Thursday, April 30, 2009

Osteotomy

PROCEDURE OF THE DAY

Osteotomy

An osteotomy is a surgical operation whereby a bone is cut to shorten, lengthen, or change its alignment. It is sometimes performed to correct a hallux valgus, or to straighten a bone that has healed crookedly following a fracture. It is also used to correct a coxa vara, genu valgum, and genu varum. The operation is done under a general anaesthetic.

Osteotomy is one method to relieve pain in arthritis, especially of the hip and knee. It is being replaced by joint replacement in the older patient.

Due to the serious nature of this procedure, recovery may be extensive. Careful consultation with a physician is important in order to ensure proper planning during a recovery phase. Tools exist to assist recovering patients who may have non weight bearing requirements and include bedpans, dressing sticks, long-handled shoe-horns, grabbers/reachers and specialized walkers and wheelchairs.


Osteotomies of the hip


Two main types of osteotomies are used in the correction of hip dysplasias and deformities to improve alignment/interaction of acetabulum - (socket) - and femoral head (femur head) - (ball), innominate osteotomies and femoral osteotomies. The bones are cut, reshaped or partially removed to realign the load bearing surfaces of the joint.

Adjustments are made to part of the hip-bone. Many operating methods and variations have been developed. They are defined by the type of cut and adjustment made Some acetabular procedures are named after the surgeons who first described them as Salter (R. Salter), Dega (W. Dega), Sutherland (D.H. Sutherland), Chiari (K. Chiari): other names one may encounter are Ludlov, P. Pemberton, and James B. Steele. Some are named after the shape of cut (e.g. Chevron, Wedge) or the way the bones are aligned (Dial=old style rotary dial phone).

Femoral osteotomies, as the name indicates, involves adjustments made to the femur head and/or the femur.[1]

Osteotomy of the knee


Knee osteotomy is commonly used to realign arthritic damage on one side of the knee. The goal is to shift the patient's body weight off the damaged area to the other side of the knee, where the cartilage is still healthy. Surgeons remove a wedge of the shinbone from underneath the healthy side of the knee, which allows the shinbone and thighbone to bend away from the damaged cartilage.

A model for this is the hinges on a door. When the door is shut, the hinges are flush against the wall. As the door swings open, one side of the door remains pressed against the wall as space opens up on the other side. Removing just a small wedge of bone can "swing" the knee open, pressing the healthy tissue together as space opens up between the thighbone and shinbone on the damaged side so that the arthritic surfaces do not rub against each other.

Osteotomy is also used as an alternative treatment to total knee replacement in younger and active patients. Because prosthetic knees may wear out over time, an osteotomy procedure can enable younger, active osteoarthritis patients to continue using the healthy portion of their knee. The procedure can delay the need for a total knee replacement for up to ten years.

Surgery

The location of the removed wedge of bone depends on where osteoarthritis has damaged the knee cartilage. The most common type of osteotomy performed on arthritic knees is a high tibial osteotomy, which addresses cartilage damage on the inside (medial) portion of the knee. The procedure usually takes 60 to 90 minutes to perform.

During a high tibial osteotomy, surgeons remove a wedge of bone from the outside of the knee, which causes the leg to bend slightly inward. This resembles the realigning of a bowlegged knee to a knock-kneed position. The patient's weight is transferred to the outside (lateral) portion of the knee, where the cartilage is still healthy.

After regional or general anesthesia is administered, the surgical team sterilizes the leg with antibacterial solution. Surgeons map out the exact size of the bone wedge they will remove, using an X-ray, CT scan, or 3D computer modeling. A four- to five-inch incision is made down the front and outside of the knee, starting below the kneecap and extending below the top of the shinbone.

Guide wires are drilled into the top of the shinbone (tibia plateau) from the outside (lateral side) of the knee. The wires usually outline a triangle form in the shinbone.

A standard oscillating saw is run along the guide wires, removing most of the bone wedge from underneath the outside of the knee, below the healthy cartilage. The cartilage surface on the top of the outside (lateral side) of the shinbone is left intact. The top of the shinbone is then lowered on the outside and attached with surgical staples or screws, depending on the size of the wedge that was removed. The layers of tissue in the knee are stitched together, usually with absorbable sutures.

Rehabilitation and Prevention


A fall or torque to the leg during the first two months after surgery may jeopardize healing. Patients must exercise extreme caution during all activities, including walking, until healing is complete.

After rehabilitation, preventing osteoarthritis involves slowing the progression and spread of the disease. Maintaining aerobic cardiovascular fitness has been an effective method for preventing the progression of osteoarthritis. Light, daily exercise is much better for an arthritic knee than occasional, heavy exercise.

It is especially important to avoid any serious knee injuries, such as torn ligaments or fractured bones, because arthritis can complicate knee injury treatment. High-impact or repetitive stress sports, like football and distance running, should be avoided.

Because osteoarthritis has multiple causes and may be related to genetic factors, no universal prevention tactic exists.

General recommendations include:

* Avoid activities that causes pain which lasts over an hour.
* Perform controlled range of motion activities that do not overload the joint.
* Avoid heavy impact on the knees during everyday and athletic activities.
* Gently strengthen thigh and lower leg muscles to help protect the bones and cartilage in the knee.
* Non-contact activities keep joints and bones healthy and maintain fitness over time. Exercise also helps promote weight loss, which can take stress off knees.

Osteotomy of the jaw


Mandibular and Maxillary


This is performed to realign your mandible (lower jaw) or your maxilla (upper jaw) with the rest of your skull and/or teeth. This is usually performed to prevent premature erosion of the teeth and temporomandibular joints, or to correct facial deformities such as mandibular retrognathia. There is little scarring, and all of the surgery takes places inside of the mouth. Othodontic braces may have to be worn pre- and post- operation to realign the teeth to match the newly religned jaw.

Veterinary Osteotomy Procedures

In veterinary medicine, osteotomies are frequently performed to address rupture of the canine cranial cruciate ligament, which is analogous to the anterior cruciate ligament. The tibial plateau leveling osteotomy and tibial tuberosity advancement are two of the most common ostetomy procedures performed in the United States. Recovery is often 6-8 weeks and the osteotomy can be filled with autologous bone grafts, scaffolds (hydroxyapatite, TR Matrix, etc.) or ceramics.

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Anterior Cruciate Ligament Reconstruction

Wednesday, April 29, 2009

Bone Grafting

PROCEDURE OF THE DAY

Bone Grafting

Bone grafting is a surgical procedure that replaces missing bone with material from the patient's own body, an artificial, synthetic, or natural substitute. Bone grafting is used to repair bone fractures that are extremely complex, pose a significant health risk to the patient, or fail to heal properly.


Types and Tissue Sources

Autologous bone grafting

Autologous (or autogenous) bone grafting is the most desired. Autogenous bone grafting involves taking the patient's own bone from a part of the body where it is not essential (typically from the pelvis or iliac crest), and placing it where it's needed. Autogenous bone grafts are the most preferred by surgeons because there is less risk of the bone being rejected due to the fact that the bone originated in the patient's body [1], and therefore has the most abundant "amount of the patient's bone growing cells and proteins" and is a kind of "outline" for the new bone that is growing. One negative aspect of the procedure would be that the surgeon has to make more incisions than are required for the surgical site; he or she must make an extra incision to extract the bone that is being used for the surgery. An effect of this is "another location for postoperative pain" and it may increase the price of the procedure.[2]

Autologous bone is typically harvested from intra-oral sources as the chin or extra-oral sources as the iliac crest, the fibula, the ribs, the mandible and even parts of the skull.

All bone requires a blood supply in the transplanted site. Depending on where the transplant site is and the size of the graft, an additional blood supply may be required. For these types of grafts, extraction of the part of the periosteum and accompanying blood vesels along with donor bone is required. This kind of graft is known as a free flap graft.

Allograft bone grafting


Allograft bone grafting is similar to the autogenous bone graft in that it is still harvested from people. Allograft bone in bone taken from cadavers or deceased people that have donated their bone so that it can be used for living people who are in need of it; it is typically sourced from a bone bank. The bone is disinfected and then frozen or lyophilized (freeze-dried).[2] It helps minimize problems that come with taking the patient's bone and takes the place of a bone graft extender or replacement in the procedure. A disadvantage of this type of graft is that it is not very successful; it is fairly useful in several types of spinal fusions, but because it is not a very powerful "biological stimulant", it cannot, when used as the only grafting material, typically achieve a good fusion in procedures such as a lumbar spinal fusion.[1]

Demineralized Bone Matrix

To demineralize bone, proteins that help with bone formation are taken from bones and are processed. Demineralized bone is suggested as only a bone graft extender because there really isn't much proof that it is "powerful enough" to fuse a human spine.[1]

Synthetic variants


Other alternatives to using a patient's own bone include ceramics, calcium phosphates, and various synthetic materials--all of which are not biologically active. Some remedies to this problem include "supercharging the materials by adding bone marrow aspirate", a procedure that involves soaking bone marrow cells onto synthetic materials, which gives the materials more biological activity. To some disappointment, studies have shown that this method is somewhat inferior to autogenous bone grafting simply because of the longevity of the graft is finite whereas autogenous grafts last for a lifetime.[1]

Xenografts


Xenograft bone substitute has its origin from a species other than human, such as bovine. Xenografts are usually only distributed as a calcified matrix.

Alloplastic Grafts

Alloplastic grafts may be made from hydroxylapatite, a naturally occurring mineral that is also the main mineral component of bone. They may be made from bioactive glass. Hydroxylapetite is a Synthetic Bone Graft, which is the most used now among other synthetic due to its osteoconduction, hareness and acceptability by bone there are also calcium carbonate which start to decrease in usage because it is completely resorbable in short time which make the bone easy to break again finally used is the tricalcium phosphate which now used in combination with hydroxylapatite thus give both effect osteoconduction and resorbsbility.

Growth Factors


Growth Factor enhanced grafts are produced using recombinant DNA technology. They consist of either Human Growth Factors or Morphogens (Bone Morphogenic Proteins in conjunction with a carrier medium, such as collagen).

Uses


The most common use of bone grafting is in the application of dental implants, in order to restore the edentulous area of a missing tooth. Dental implants require bones underneath them for support and to have the implant integrate properly into the mouth. People who have been edentulous (without teeth) for a prolonged period may not have enough bone left in the necessary locations. In this case, bone can be taken from the chin or from the pilot holes for the implants or even from the iliac crest of the pelvis and inserted into the mouth underneath the new implant.

In general, bone grafts are either used en block (such as from the chin or the ascending ramus area of the lower jaw) or particulated, in order to be able to adapt it better to a defect.

Another common bone graft, which is more substantial than those used for dental implants, is of the fibular shaft. After the segment of the fibular shaft has been removed normal activities such as running and jumping are permitted on the leg with the bone deficit. The grafted, vascularized fibulas have been used to restore skeletal integrity to long bones of limbs in which congenital bone defects exist and to replace segments of bone after trauma or malignant tumor invasion. The periosteum and nutrient artery are generally removed with the piece of bone so that the graft will remain alive and grow when transplanted into the new host site. Once the transplanted bone is secured into its new location it generally restores blood supply to the bone in which it has been attached.

Besides the main use of bone grafting--dental implants--this procedure is used to fuse joints to prevent movement, repair broken bones that have bone loss, and repair broken bone that has not yet healed.[3]

Bone grafts are used in hopes that the defective bone will be healed or will regrow with little to no graft rejection.[3]

Procedure

Depending on where the bone graft is needed, a different doctor may be requested to do the surgery. Doctors that do bone graft procedures are commonly orthopedic surgeons, otolaryngology head and neck surgeons, neurosurgeons, craniofacial surgeons, oral and maxillofacial surgeons, and periodontists.[4]

Risks

As with any procedure, there are risks involved; among these include reactions to medicine and problems breathing, bleeding, and infection.[3]Infection is reported to occur in less than 1% of cases and is curable with antibiotics. Overall, patients with a preexisting illness are at a higher risk of getting an infection as opposed to those who are overall healthy.[5]

Risks for grafts from the iliac crest

Some of the potential risks and complications of bone grafts employing the iliac crest as a donor site include[5][6][7]:

* acquired bowel herniation (this becomes a risk for larger donor sites (>4 cm))[5]. About 20 cases have been reported in the literature from 1945 till 1989[8] and only a few hundred cases have been reported worldwide[9]
* meralgia paresthetica (injury to the lateral femoral cutaneous nerve also called Bernhardt-Roth's syndrome)
* pelvic instability
* fracture (extremely rare and usually with other factors[10][11])
* injury to the clunial nerves (this will cause posterior pelvic pain which is worsened by sitting)
* injury to the ilioinguinal nerve
* infection
* minor hematoma (a common occurrence)
* deep hematoma requiring surgical intervention
* seroma
* ureteral injury
* pseudoaneurysm of iliac artery (rare)[12]
* tumor transplantation
* cosmetic defects (chiefly caused by not preserving the superior pelvic brim)
* chronic pain

Bone grafts harvested from the posterior iliac crest in general have less morbidity, but depending on the type of surgery, may require a flip while the patient is under general anesthesia.[13][14]

Recovery and Aftercare


The amount of time it takes for an individual to recovery depends on the severity of the injury being treated and lasts anywhere from 2 weeks to 2 months with a possibility of vigorous exercise being barred for up to 6 months.[3]

Costs

Bone graft procedures consist of more than just the surgery. The average cost of bone graft procedures ranges from approximately $33,860 to $37,227.[15] Besides the cost of the bone graft itself (ranging from $250 to $900) other expenses for the procedure include: surgeon's fees (these vary), anesthesiologist fees (approximately $350 to $400 per hour), hospital charges (these vary; averaging about $1,500 to $1,800 a day), medication charges ($200 to $400), and additional fees for services such as medical supplies, diagnostic procedures, equipment use fees, etc.

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Osteotomy

Tuesday, April 28, 2009

Lung Transplantation

PROCEDURE OF THE DAY

Lung Transplantation

Lung transplantation is a surgical procedure in which a patient's diseased lungs are partially or totally replaced by lungs which come from a donor. While lung transplants carry certain associated risks, they can also extend life expectancy and enhance the quality of life for end-stage pulmonary patients.


Qualifying conditions

Lung transplantation is the therapeutic measure of last resort for patients with end-stage lung disease who have exhausted all other available treatments without improvement. A variety of conditions may make such surgery necessary. As of 2005, the most common reasons for lung transplantation in the United States were:[1]

* 27% chronic obstructive pulmonary disease or COPD, including emphysema;
* 16% idiopathic pulmonary fibrosis;
* 14% cystic fibrosis;
* 12% idiopathic (formerly known as "primary") pulmonary hypertension;
* 5% alpha 1-antitrypsin deficiency;
* 2% replacing previously transplanted lungs that have since failed;
* 24% other causes, including bronchiectasis and sarcoidosis.

Contraindications


Despite the severity of a patient's respiratory condition, certain preexisting conditions may make a person a poor candidate for lung transplantation. These conditions include:[2]

* concurrent chronic illness (e.g. congestive heart failure, kidney disease, liver disease);
* current infections, including HIV and hepatitis;
* current or recent cancer;
* current use of alcohol, tobacco, or illegal drugs;
* age;
* psychiatric conditions;
* history of noncompliance with medical instructions.

History


The history of organ transplants began with several attempts that were unsuccessful due to transplant rejection. Animal experimentation by various pioneers, including Vladimir Demikhov and Dominique Metras, during the 1940s and 1950s, first demonstrated that the procedure was technically feasible. James Hardy of the University of Mississippi performed the first human lung transplant in 1963.[3] Following a left lung transplantation, the patient survived for 18 days. From 1963-1978, multiple attempts at lung transplantation failed because of rejection and problems with anastomotic bronchial healing. It was only after the invention of the heart-lung machine, coupled with the development of immunosuppressive drugs such as cyclosporine, that organs such as the lungs could be transplanted with a reasonable chance of patient recovery.

The first successful transplant surgery involving the lungs was a heart-lung transplant, performed by Dr. Bruce Reitz of Stanford University on a woman who had idiopathic pulmonary hypertension.[4]

* 1983: First successful single lung transplant (Tom Hall) by Joel Cooper (Toronto)[5]
* 1986: First successful double lung transplant (Ann Harrison) by Joel Cooper (Toronto)[6]
* 1988: First successful double lung transplant for cystic fibrosis by Joel Cooper (Toronto)

Transplant requirements


Requirements for potential donors

There are certain requirements for potential lung donors, due to the needs of the potential recipient. In the case of living donors, this is also in consideration of how the surgery will affect the donor.[2]

* healthy;
* size match; the donated lung or lungs must be large enough to adequately oxygenate the patient, but small enough to fit within the recipient's chest cavity;
* age;
* blood type.

Requirements for potential recipients

While each transplant center is free to set its own criteria for transplant candidates, certain requirements are generally agreed upon:[2]

* end-stage lung disease;
* has exhausted other available therapies without success;
* no other chronic medical conditions (e.g. heart, kidney, liver);
* no current infections or recent cancer. There are certain cases where preexisting infection is unavoidable, as with many patients with cystic fibrosis. In such cases, transplant centers, at their own discretion, may accept or reject patients with current infections of B. cepacia or MRSA.
* no HIV or hepatitis;
* no alcohol, smoking, or drug abuse;
* within an acceptable weight range (marked undernourishment or obesity are both associated with increased mortality);
* age (single vs. double tx);
* acceptable psychological profile;
* has social support system;
* financially able to pay for expenses;
* able to comply with post-transplant regimen. A lung transplant is a major operation, and following the transplant, the patient must be willing to adhere to a lifetime regimen of medications as well as continuing medical care.

Medical tests for potential transplant candidates

Patients who are being considered for placement on the organ transplant list must undergo an extensive series of medical tests in order to evaluate their overall health status and suitability for transplant surgery.[7]

* blood typing; the blood type of the recipient must match that of the donor due to certain antigens that are present on donated lungs. A mismatch of blood type can lead to a strong response by the immune system and subsequent rejection of the transplanted organs;
* tissue typing; ideally, the lung tissue would also match as closely as possible between the donor and the recipient, but the desire to find a highly compatible donor organ must be balanced against the patient's immediacy of need;
* Chest X-ray - PA & LAT, to verify the size of the lungs and the chest cavity;
* pulmonary function tests;
* CT Scan (High Resolution Thoracic & Abdominal);
* Bone mineral density scan;
* MUGA (Gated cardiac blood pool scan);
* Cardiac stress test (Dobutamine/Thallium scan);
* ventilation/perfusion (V/Q) scan;
* electrocardiogram;
* cardiac catheterization;
* echocardiogram.

Lung allocation score


Prior to 2005, donor lungs within the United States were allocated by the United Network for Organ Sharing on a first-come, first-serve basis to patients on the transplant list. This was replaced by the current system, in which prospective lung recipients of age of 12 and older are assigned a lung allocation score or LAS, which takes into account various measures of the patient's health. The new system allocates donated lungs according to the immediacy of need rather than how long a patient has been on the transplant list. Patients who are under the age of 12 are still given priority based on how long they have been on the transplant waitlist. The length of time spent on the list is also the deciding factor when multiple patients have the same lung allocation score.

Patients who are accepted as good potential transplant candidates must carry a pager with them at all times in case a donor organ becomes available. These patients must also be prepared to move to their chosen transplant center at a moment's notice. Such patients may be encouraged to limit their travel within a certain geographical region in order to facilitate rapid transport to a transplant center.

Types of lung transplant


Lobe

A lobe transplant is a surgery in which part of a living donor's lung is removed and used to replace part of recipient's diseased lung. This procedure usually involves the donation of lobes from two different people, thus replacing a single lung in the recipient. Donors who have been properly screened should be able to maintain a normal quality of life despite the reduction in lung volume.

Single-lung


Many patients can be helped by the transplantation of a single healthy lung. The donated lung typically comes from a donor who has been pronounced brain-dead.

Double-lung

Certain patients may require both lungs to be replaced. This is especially the case for people with cystic fibrosis, due to the bacterial colonisation commonly found within such patients' lungs; if only one lung were transplanted, bacteria in the native lung could potentially infect the newly transplanted organ.

Heart-lung

Some respiratory patients may also have severe cardiac disease which in of itself would necessitate a heart transplant. These patients can be treated by a surgery in which both lungs and the heart are replaced by organs from a donor or donors.

A particularly involved example of this has been termed a "domino transplant" in the media. First performed in 1987, this type of transplant typically involves the transplantation of a heart and lungs into recipient A, whose own healthy heart is removed and transplanted into recipient B.[8]

Procedure


While the precise details of surgery will depend on the exact type of transplant, there are many steps which are common to all of these procedures. Prior to operating on the recipient, the transplant surgeon inspects the donor lung(s) for signs of damage or disease. If the lung or lungs are approved, then the recipient is connected to an IV line and various monitoring equipment, including pulse oximetry. The patient will be given general anesthesia, and a machine will breathe for him or her.[9]

It takes about one hour for the pre-operative preparation of the patient. A single lung transplant takes about four to eight hours, while a double lung transplant takes about six to twelve hours to complete. A history of prior chest surgery may complicate the procedure and require additional time.[9]

Lobe


Single-lung

Incision scarring from a double lung transplant.

In single-lung transplants, the lung with the worse pulmonary function is chosen for replacement. If both lungs function equally, then the right lung is usually favored for removal because it avoids having to maneuver around the heart, as would be required for excision of the left lung.[2]

In a single-lung transplant the process starts out after the donor lung has been inspected and the decision to accept the donor lung for the patient has been made. An incision is generally made from under the shoulder blade around the chest, ending near the sternum. An alternate method involves an incision under the breastbone.[1] In the case of a singular lung transplant the lung is collapsed, the blood vessels in the lung tied off, and the lung removed at the bronchial tube. The donor lung is placed, the blood vessels reattached, and the lung reinflated. To make sure the lung is satisfactory and to clear any remaining blood and mucus in the new lung a bronchoscopy will be performed. When the surgeons are satisfied with the performance of the lung the chest incision will be closed.

Double-lung

A double-lung transplant, also known as a bilateral transplant, can be executed either sequentially, en bloc, or simultaneously. Sequential is more common than en bloc.[2] This is effectively like having two separate single-lung transplants done. A less common alternative is the transplantation of both lungs en bloc or simultaneously.

The transplantation process starts after the donor lungs are inspected and the decision to transplant has been made. An incision is then made from under the patient's armpit, around to the sternum, and then back towards the other armpit, this is known as a clamshell incision. In the case of a sequential transplant the recipients lung with the poorest lung functions is collapsed, the blood vessels tied off, and cut at the corresponding bronchi. The new lung is then placed and the blood vessels reattached. To make sure the lung is satisfactory before transplanting the other a bronchoscopy is performed. When the surgeons are satisfied with the performance of the new lung, surgery on the second lung will proceed. In 10% to 20% of double-lung transplants the patient is hooked up to a heart-lung machine which pumps blood for the body and supplies fresh oxygen.[1]

Post-operative care

Immediately following the surgery, the patient is placed in an intensive care unit for monitoring, normally for a period of a few days. The patient is put on a ventilator to assist breathing. Nutritional needs are generally met via total parenteral nutrition, although in some cases a nasogastric tube is sufficient for feeding. Chest tubes are put in so that excess fluids may be removed. Because the patient is confined to bed, a urinary catheter is used. IV lines are used in the neck and arm for monitoring and giving medications.[9] After a few days, barring any complications, the patient may be transferred to a general inpatient ward for further recovery. The average hospital stay following a lung transplant is generally one to three weeks, though complications may require a longer period of time.[9] After this stage, patients are typically required to attend rehabilitation gym for approximately 3 months to regain fitness. Light weights, exercise bike, treadmill, stretches and more are all a part of the rehabilitation programme.

There may be a number of side effects following the surgery. Because certain nerve connections to the lungs are cut during the procedure, transplant recipients cannot feel the urge to cough or feel when their new lungs are becoming congested. They must therefore make conscious efforts to take deep breaths and cough in order to clear secretions from the lungs.[10] Their heart rate responds less quickly to exertion due to the cutting of the vagus nerve that would normally help regulate it.[11] They may also notice a change in their voice due to potential damage to the nerves that coordinate the vocal cords.[11]

Miscellaneous


Post-transplant patients are held from driving for the first 3 months pending an assessment of the patients capacity to drive, this assessment is usually performed by an occupational therapist. Eye sight, physical ability to do simple actions such as check blind spots, wear a seat belt safely without the wound site being affected and hand eye coordination are all assessed.

Hygiene becomes more important in every day living because due to the Immunosuppressant drugs which are required every day to prevent transplant rejection. Lack of a strong immune system leaves transplant recipients vulnerable to infections. Care must be taken into food preparation and hygiene as gastroenteritis becomes more of a risk.

Risks


As with any surgical procedure, there are risks of bleeding and infection. The newly transplanted lung itself may fail to properly heal and function. Because a large portion of the patient's body has been exposed to the outside air, sepsis is a possibility, so antibiotics will be given to try to prevent that.

Transplant rejection is a primary concern, both immediately after the surgery and continuing throughout the patient's life. Because the transplanted lung or lungs come from another person, the recipient's immune system will "see" it as an invader and attempt to neutralize it. Transplant rejection is a serious condition and must be treated as soon as possible.

Signs of rejection:[1]

* fever;
* flu-like symptoms, including chills, dizziness, nausea, general feeling of illness, night sweats;
* increased difficulty in breathing;
* worsening pulmonary test results;
* increased chest pain or tenderness;
* increase or decrease in body weight of more than 2 kilograms in a 24'hour period.

In order to prevent transplant rejection and subsequent damage to the new lung or lungs, patients must take a regimen of immunosuppressive drugs. Patients will normally have to take a combination of these medicines in order to combat the risk of rejection. This is a lifelong commitment, and must be strictly adhered to. The immunosuppressive regimen is begun just before or after surgery. Usually the regimen includes cyclosporine, azathioprine and corticosteroids, but as episodes of rejection may reoccur throughout a patient's life, the exact choices and dosages of immunosuppressants may have to be modified over time. Sometimes tacrolimus is given instead of cyclosporine and mycophenolate mofetil instead of azathioprine.

The immunosuppressants that are needed to prevent organ rejection also introduce some risks. By lowering the body's ability to mount an immune reaction, these medicines also increase the chances of infection. Antibiotics may be prescribed in order to treat or prevent such infections. Certain medications may also have nephrotoxic or other potentially harmful side-effects. Other medications may also be prescribed in order to help alleviate these side effects. There is also the risk that a patient may have an allergic reaction to the medications. Close follow-up care is required in order to balance the benefits of these drugs versus their potential risks.

Chronic rejection, meaning repeated bouts of rejection symptoms beyond the first year after the transplant surgery, occurs in approximately 50% of patients.[12] Such chronic rejection presents itself as bronchiolitis obliterans, or less frequently, atherosclerosis.[12]

Prognosis


These statistics are based on data from 2006. The source data made no distinction between living and deceased donor organs, nor was any distinction made between lobar, single, and double lung transplants.[13]
1 year survival 5 years survival 10 years survival
Lung transplant 84.9% 51.6% 25.6%
Heart-lung transplant 77.8% 43.6% 27.3%

Transplanted lungs typically last three to five years before showing signs of failure.

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Bone Grafting

Monday, April 27, 2009

Pancreas Transplantation

PROCEDURE OF THE DAY

Pancreas Transplantation

A pancreas transplant is an organ transplant that involves implanting a healthy pancreas (one that can produce insulin) into a person who usually has diabetes. Because the pancreas is a vital organ, performing functions necessary in the digestion process, the recipient's native pancreas is left in place, and the donated pancreas is attached in a different location. In the event of rejection of the new pancreas which would quickly cause life-threatening diabetes, the recipient could not survive without the native pancreas still in place. The healthy pancreas comes from a donor who has just died or it may be a partial pancreas from a living donor. [1] At present, pancreas transplants are usually performed in persons with insulin-dependent diabetes, who have severe complications that are usually of a renal nature. Patients with pancreatic cancer are not eligible for valuable pancreatic transplantations, since the condition has a very high mortality rate and the disease, being highly malignant, could and probably would soon return.


Types

There are three main types of pancreas transplantation:

* Simultaneous pancreas-kidney transplant (SPK), when the pancreas and kidney are transplanted simultaneously from the same deceased donor.
* Pancreas-after-kidney transplant (PAK), when a cadaveric, or deceased, donor pancreas transplant is performed after a previous, and different, living or deceased donor kidney transplant.
* Pancreas transplant alone, for the patient with type 1 diabetes who usually has severe, frequent hypoglycemia, but adequate kidney function.

Indications


In most cases, pancreas transplantation is performed on individuals with type 1 diabetes with end-stage renal disease The majority of pancreas transplantations (>90%) are simultaneous pancreas-kidney transplantions.[2]

Preservation until implantation

Standard practice is to replace the donor's blood in the pancreatic tissue with an ice-cold organ storage solution, such as UW (Viaspan) or HTK until the allograft pancreatic tissue is implanted.

Complications

Complications immediately after surgery include rejection, thrombosis, pancreatitis and infection.

Prognosis


The prognosis after pancreas transplantation is very good. Over the recent years, long-term success has improved and risks have decreased. One year after transplantation more than 95% of all patients are still alive and 80-85% of all pancreases are still functional. After transplantation patients need lifelong immunosuppression. Immunosuppression increases the risk for a number of different kinds of infection[3] and cancer.

History

The first pancreas transplantation was performed in 1966 by the team of Dr. Kelly, Dr. Lillehei, Dr.Merkel, Dr.Idezuki Y, & Dr. Goetz, three years after the first kidney transplantation.[4] A pancreas along with kidney and duodenum was transplanted into a 28-year-old woman and her blood sugar levels decreased immediately after transplantation, but eventually she died three months later from pulmonary embolism. In 1979 the first living-related partial pancreas transplantation was done.

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Lung Transplantation

Sunday, April 26, 2009

Renal Transplantation

PROCEDURE OF THE DAY

Renal Transplantation

Kidney transplantation or renal transplantation is the organ transplant of a kidney in a patient with end-stage renal disease. Kidney transplantation is typically classified as deceased-donor (formerly known as cadaveric) or living-donor transplantation depending on the source of the recipient organ. Living-donor renal transplants are further characterized as genetically related (living-related) or non-related (living-unrelated) transplants, depending on whether a biological relationship exists between the donor and recipient.


History


The first documented kidney transplant in the United States was performed June 17, 1950, on Ruth Tucker, a 44-year-old woman with polycystic kidney disease, at Little Company of Mary Hospital in Evergreen Park, Illinois, a Chicago suburb. Although the donated kidney was rejected because no immunosuppressive therapy was available at the time – the development of effective antirejection drugs was years away – Tucker's remaining diseased kidney began working again and she lived another 5 years before dying of an unrelated illness.[citation needed] Thereafter, successful kidney transplantations were undertaken in 1954 in Boston and Paris. The Boston transplantation was done between identical twins to eliminate any problems of an immune reaction. The first kidney transplant in the United Kingdom did not occur until 1960, when Michael Woodruff performed one between identical twins in Edinburgh. Until the routine use of medications to prevent and treat acute rejection, introduced in 1964, deceased donor transplantation was not performed. The kidney was the easiest organ to transplant, tissue-typing was simple, the organ was relatively easy to remove and implant, live donors could be used without difficulty, and in the event of failure, kidney dialysis was available from the 1940s. Tissue typing was essential to the success: early attempts in the 1950s on sufferers from Bright's disease had been very unsuccessful. In 1954, Dr. Joseph E. Murray performed the world's first successful renal transplant between genetically identical patients, for which he won the Nobel Prize for Medicine in 1990. The donor is still alive as of 2005; the recipient died eight years after the transplantation.

The major barrier to organ transplantation between genetically non-identical patients lay in the recipient's immune system, which would treat a transplanted kidney as a "non-self" and immediately or chronically, reject it. Thus, having medications to suppress the immune system was essential. However, suppressing an individual's immune system places that individual at greater risk of infection and cancer (particularly skin cancer and lymphoma), in addition to the side effects of the medications.

The basis for most immunosuppressive regimens is prednisolone, a corticosteroid. Prednisolone suppresses the immune system, but its long-term use at high doses carries a multitude of side effects, including glucose intolerance and diabetes, weight gain, osteoporosis, muscle weakness, hypercholesterolemia, and cataract formation amongst others. Prednisolone alone is usually inadequate to prevent rejection of a transplanted kidney. Thus other, non-steroid immunosuppressive agents are needed, which also allow lower doses of prednisolone.

Indications


The indication for kidney transplantation is end-stage renal disease (ESRD), regardless of the primary cause. This is defined as a drop in the glomerular filtration rate (GFR) to 20-25% of normal. Common diseases leading to ESRD include malignant hypertension, infections, diabetes mellitus and glomerulonephritis; genetic causes include polycystic kidney disease as well as a number of inborn errors of metabolism as well as autoimmune conditions including lupus and Goodpasture's syndrome. Diabetes is the most common cause of kidney transplant, accounting for approximately 25% of those in the US. The majority of renal transplant recipients are on some form of dialysis – hemodialysis, peritoneal dialysis, or the similar process of hemofiltration – at the time of transplantation. However, individuals with chronic renal failure who have a living donor available often elect to undergo transplantation before dialysis is needed.

Contraindications and requirements

Contraindications include both cardiac and pulmonary insufficiency, as well as hepatic disease. Concurrent tobacco use and morbid obesity are also among the indicators putting a patient at a higher risk for surgical complications.

Kidney transplant requirements vary from program to program and country to country. Many programs place limits on age (e.g. the person must be less than 69 years old when put on the waiting list) and require that one must be in good health (aside from the kidney disease).

Significant cardiovascular disease, incurable terminal infectious diseases and cancer often are transplant exclusion criteria. In addition, candidates are typically screened to determine if they will be compliant with their medications, which is essential for survival of the transplant. People with mental illness and/or significant on-going substance abuse issues may be excluded. HIV was at one point considered to be a complete contraindication to transplantation. There was fear that immunosuppressing someone with a depleted immune system would result in the progression of the disease. However, current research does not bear out this fear; in fact there are findings that immunosuppressive drugs and antiretrovirals may work synergistically to help both HIV viral loads/CD4 cell counts and prevent active rejection.

Sources of kidneys

Since medication to prevent rejection is so effective, donors need not be genetically similar to their recipient. Most donated kidneys come from deceased donors, with some coming from living donors. However, the utilization of living donors in the United States is on the rise. In the year 2006, 47% of donated kidneys were actually from living donors (Organ Procurement and Transplantation Network, 2007). It is important to note that this varies by country: for example, only 3% of transplanted kidneys during 2006 in Spain came from living donors (Organización Nacional de Transplantes (ONT), 2007).

Living donors


More than one in three donations in the UK is now from a live donor,[1] and almost one in three in Israel.[2] The percentage of transplants from living donors is increasing. Potential donors are carefully evaluated on medical and psychological grounds. This ensures that the donor is fit for surgery and has no disease which brings undue risk or likelihood of a poor outcome for either the donor or recipient. The psychological assessment is to ensure the donor gives informed consent and is not coerced. In countries where paying for organs is illegal, the authorities may also seek to ensure that a donation has not resulted from a financial transaction. In the UK the Human Tissue Act of 2004 dictated that donors must prove a familial or long term relationship or enduring friendship, for instance by providing photographs of themselves together spread over a period of time, or a birth or wedding certificate. Purely altruistic donation to strangers has recently been accepted by the Human Tissue Authority in the United Kingdom, and as of December 2007 only four people had been given permission to do this under the HTA. The decision must be approved by a panel, whereas the typical donation based on relationship is required only to go through an executive.[3] There is good evidence that kidney donation is not associated with long term harm to the donor.[4]

Traditionally, the donor procedure has been through a single, 4 to 7 inch incision but live donation is being increasingly performed by laparoscopic surgery. This reduces pain and accelerates recovery for the donor. Operative time and complications decreased significantly after a surgeon performed 150 cases. Live donor kidney grafts tend to perform better than those from deceased donors.[5] Since the increase in the use of laparascopic surgery, the number of live donors has increased. Any advance which leads to a decrease in pain and scarring and swifter recovery has the potential to boost donor numbers.

The recent removal of a donor kidney through a bodily orifice has been said to be interesting for this reason, though it was rendered more possible because the woman had a previous hysterectomy.[6] The extraction was performed using Natural orifice transluminal endoscopic surgery, where an endoscope is inserted through an orifice, then through an internal incision, so that there is no external scar. The donor was able to leave hospital within 48 hours. The recent advance of Single port access surgery requiring only one entry point at the navel is another advance with possible potential for more frequent use.

In 2004 the FDA approved the Cedars-Sinai High Dose IVIG therapy which reduces the need for the living donor to be the same blood type (ABO compatible) or even a tissue match[7]. The therapy reduced the incidence of the recipient's immune system rejecting the donated kidney in highly-sensitized patients[7].

Organ trade

For the main article on this subject, see Organ trade

In the developing world some people sell their organs. Such people are often in a situation of grave poverty,[8] or exploited by salespersons. People travelling to make use of such kidneys, sometimes known as "transplant tourists", are not looked upon favourably for instance by the NHS, who may be loath to treat them, and they have increased complications due to poor infection control and lower medical and surgical standards. One surgeon has said organ trade could be legalized in the UK to prevent such tourism, but this is not seen by the National Kidney Research Fund as the answer to a deficit in donors.[9]

Deceased donors


Deceased donors can be divided in two groups:

* Brain-dead (BD) donors
* Donation after Cardiac Death (DCD) donors

Although brain-dead (or "heart-beating") donors are considered dead, the donor's heart continues to pump and maintain the circulation. This makes it possible for surgeons to start operating while the organs are still being perfused. During the operation, the aorta will be cannulated, after which the donor's blood will be replaced by an ice-cold storage solution, such as UW (Viaspan), HTK, or Perfadex. [Depending on which organs are transplanted, more than one solution may be used simultaneously.] Due to the temperature of the solution (and since large amounts of cold NaCl-solution are poured over the organs for a rapid cooling of the organs), the heart will stop pumping.

"Donation after Cardiac Death" donors are patients who do not meet the brain-dead criteria, but due to the small chance of recovery have elected, via a living will or through family, to withdraw support. In this procedure, treatment is discontinued (mechanical ventilation is shut off). Usually, a certain amount of minutes after death has been pronounced, the patient is rushed to the operating theatre, where the organs are recovered, after which the storage solution is flushed through the organs itself. Since the blood is no longer being circulated, coagulation must be prevented with relatively large amounts of anti-coagulation agents, such as heparin. It is important to note that several ethical and procedural guidelines must be followed, chief of which is that the organ recovery team should not participate in the patient's care in any manner until after death has been declared.

Kidneys from brain-dead donors are generally of a superior quality, since they have not been exposed to warm ischemia (the time between the heart stopping and the kidney being cooled).

Compatibility


If plasmapheresis or IVIG is not performed, the donor and recipient have to be ABO blood group compatible. Also, they should ideally share as many HLA and "minor antigens" as possible. This decreases the risk of transplant rejection and the need for another transplant. The risk of rejection may be further reduced if the recipient is not already sensitized to potential donor HLA antigens, and if immunosuppressant levels are kept in an appropriate range. In the United States, up to 17% of all deceased donor kidney transplants have no HLA mismatch. However, it is important to note that HLA matching is a relatively minor predictor of transplant outcomes. In fact, living non-related donors are now almost as common as living (genetically)-related donors.

In the 1980s, experimental protocols were developed for ABO-incompatible transplants using increased immunosuppression and plasmapheresis. Through the 1990s these techniques were improved and an important study of long-term outcomes in Japan was published. [1]. Now, a number of programs around the world are routinely performing ABO-incompatible transplants. [2]

In 2004 the FDA approved the Cedars-Sinai High Dose IVIG protocol which eliminates the need for the donor to be the same blood type. [3]

Procedure

Since in most cases the barely functioning existing kidneys are not removed because this has been shown to increase the rates of surgical morbidities, the kidney is usually placed in a location different from the original kidney (often in the iliac fossa), and as a result it is often necessary to use a different blood supply:

* The renal artery of the kidney, previously branching from the abdominal aorta in the donor, is often connected to the external iliac artery in the recipient.
* The renal vein of the new kidney, previously draining to the inferior vena cava in the donor, is often connected to the external iliac vein in the recipient.

Kidney-pancreas transplant


Occasionally, the kidney is transplanted together with the pancreas. This is done in patients with diabetes mellitus type I, in whom the diabetes is due to destruction of the beta cells of the pancreas and in whom the diabetes has caused renal failure (diabetic nephropathy). This is almost always a deceased donor transplant. Only a few living donor (partial) pancreas transplants have been done. For individuals with diabetes and renal failure, the advantages of earlier transplant from a living donor (if available) are far superior to the risks of continued dialysis until a combined kidney and pancreas are available from a deceased donor.[citation needed]

These procedures are commonly abbreviated as follows:

* "SKP transplant", for "simultaneous kidney-pancreas transplant"
* "PAK transplant", for "pancreas after kidney transplant"

(By contrast, "PTA" refers to "Pancreas transplant alone".)

The pancreas can come from a deceased donor as well as a living one. A patient can either receive a living kidney followed by a donor pancreas at a later date (PAK, or pancreas-after-kidney) or a combined kidney-pancreas from a donor (SKP, simultaneous kidney-pancreas.)

Transplanting just the islet cells from the pancreas is still in the experimental stage, but shows promise. This involves taking a deceased donor pancreas, breaking it down, and extracting the islet cells that make insulin. The cells are then injected through a catheter into the recipient and they generally lodge in the liver. The recipient still needs to take immunosuppressants to avoid rejection, but no surgery is required. Most people need two or three such injections, and many are not completely insulin-free.

Post operation

The transplant surgery lasts about three hours. The donor kidney will be placed in the lower abdomen and its blood vessels connected to arteries and veins in the recipient's body. When this is complete, blood will be allowed to flow through the kidney again, so the ischemia time is minimized. In most cases, the kidney will soon start producing urine. Since urine is sterile, this has no effect on the operation. The final step is connecting the ureter from the donor kidney to the bladder.

Depending on its quality, the new kidney usually begins functioning immediately. Living donor kidneys normally require 3-5 days to reach normal functioning levels, while cadaveric donations stretch that interval to 7-15 days. Hospital stay is typically for four to seven days. If complications arise, additional medicines may be administered to help the kidney produce urine.

Medicines are used to suppress the immune system from rejecting the donor kidney. These medicines must be taken for the rest of the patient's life. The most common medication regimen today is : tacrolimus, mycophenolate, and prednisone. Some patients may instead take cyclosporine, rapamycin, or azathioprine. Cyclosporine, considered a breakthrough immunosuppressive when first discovered in the 1980's, ironically causes nephrotoxicity and can result in iatrogenic damage to the newly transplanted kidney. Blood levels must be monitored closely and if the patient seems to have a declining renal function, a biopsy may be necessary to determine if this is due to rejection or cyclosporine intoxication.

Acute rejection occurs in 10% to 25% of people after transplant during the first sixty days. Rejection does not necessarily mean loss of the organ, but may require additional treatment. [4]

Complications


Problems after a transplant may include:

* Transplant rejection (hyperacute, acute or chronic)
* Infections and sepsis due to the immunosuppressant drugs that are required to decrease risk of rejection
* Post-transplant lymphoproliferative disorder (a form of lymphoma due to the immune suppressants)
* Imbalances in electrolytes including calcium and phosphate which can lead to bone problems amongst other things
* Other side effects of medications including gastrointestinal inflammation and ulceration of the stomach and esophagus, hirsutism (excessive hair growth in a male-pattern distribution), hair loss, obesity, acne, diabetes mellitus (type 2), hypercholesterolemia, and others.
* The average lifetime for a donor kidney is ten to fifteen years. When a transplant fails a patient may opt for a second transplant, and may have to return to dialysis for some intermediary time.

Prognosis

Kidney transplantation is a life-extending procedure.[10] The typical patient will live ten to fifteen years longer with a kidney transplant than if kept on dialysis.[11] The years of life gained is greater for younger patients, but even 75 year-old recipients (the oldest group for which there is data) gain an average four more years' life. People generally have more energy, a less restricted diet, and fewer complications with a kidney transplant than if they stay on conventional dialysis.

Some studies seem to suggest that the longer a patient is on dialysis before the transplant, the less time the kidney will last. It is not clear why this occurs, but it underscores the need for rapid referral to a transplant program. Ideally, a kidney transplant should be pre-emptive, i.e. take place before the patient starts on dialysis.

At least three professional athletes have made a comeback to their sport after receiving a transplant: NBA players Sean Elliott and Alonzo Mourning; and New Zealand rugby union player Jonah Lomu as well as the German-Croatian Soccer Player Ivan Klasnić.

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Pancreas Transplantation

Saturday, April 25, 2009

Cardiac Transplantation

PROCEDURE OF THE DAY

Cardiac Transplantation

Heart transplantation, or cardiac transplantation, is a surgical transplant procedure performed on patients with end-stage heart failure or severe coronary artery disease. The most common procedure is to take a working heart from a recently deceased organ donor (allograft) and implant it into the patient. The patient's own heart may either be removed (orthotopic procedure) or, less commonly, left in to support the donor heart (heterotopic procedure); both are controversial "solutions" to one of the most enduring human ailments. Post-operation survival periods now average 15 years.[1]

Worldwide there are 3,500 heart transplants performed every year; about 800,000 people have a Class IV heart defect (moribund) and need a new organ.[2] This disparity has spurred considerable research into the use of non-human hearts since 1993. It is now possible to take a heart from another species (xenograft), or implant a man-made artificial one, although the outcome of these two procedures has been less successful in comparison to the far more commonly performed allografts. Engineers want to fix the remaining problems with the manufactured options in the next 15 years.[1]


History

The first heart transplant involving a human was carried out by a team led by Dr James D. Hardy on the of 23 of January 1964 at the University of Mississippi Medical Center, when the heart of a chimpanzee was transplanted into the chest of a dying man. The heart beat for only 90 minutes before stopping. The procedure raised a series of ethical and moral questions, and received copious amounts of publicity. However, it also helped pave the way for human-to-human heart transplants.

The first human-to-human heart transplant was performed by cardiac surgeon Christiaan Barnard at Groote Schuur Hospital in South Africa on the 3rd December, 1967 by a team led by Dr. Christiaan Barnard. The patient was Louis Washkansky of Cape Town, South Africa, who lived for 18 days after the procedure before dying of pneumonia. Barnard transplanted a healthy heart from a deceased patient, the donor, Denise Darvall, who was rendered brain dead in a car accident.

The first successful heart transplant in the United States was done at Stanford University by doctor Norman Shumway in January, 1968. Subsequently, another transplant was done at St. Luke's Episcopal Hospital in Houston, Texas by Denton Cooley in June 1968. The donor was a teenage suicide victim (who had had an aortic coarctation repaired as a young child, also by Dr. Cooley) and the recipient, Mr. Thomas, had terminal severe cardiomyopathy. He survived 8 months before dying of rejection of the transplanted heart. A series of five subsequent heart transplants were done that month by Dr. Cooley followed by a number of transplants in Houston that year before the program was canceled, leaving only Norman Shumway at Stanford University doing heart transplants and research on the rejection phenomenon.

On 27 April 1968, French surgeon Christian Cabrol performed the first European heart transplantation in the Paris Pitié-Salpêtrière Hospital. The patient was a 66 year old man, Clovis Roblain, who survived 53 hours before dying of a pulmonary embolism.[3]

In 1984, at two years old, Elizabeth Craze became the youngest surviving heart transplant patient. Another followed shortly in 1988, when Kimberly Martinez received a heart transplant at the age of three months old from Stanford University. At one year old, she developed lymphoma which required the removal of three-fourths of her lung. She fully recovered and since 1989 has had no further problems.[4][5]

The concept of heart transplantation dates back to at least 400 AD in China. The book of Liezi tells a story of Bian Que exchanging the hearts of two warriors to balance their personal characteristics.[6]

Indications


In order for a patient to be recommended for a heart transplant they will generally have advanced, irreversible heart failure with a severely limited life expectancy. Other possible treatments for their condition, including medication, should have been considered prior to recommendation. Generally, the following causes of heart failure can be treated with a heart transplant:

* Cardiomyopathy
* Congenital heart disease
* Coronary artery disease
* Heart valve disease
* Life-threatening arrhythmias.

Contraindications

Some patients are less suitable for a heart transplant, especially if they suffer from other circulatory conditions unrelated to the heart. The following conditions in a patient would increase the chances of complications occurring during the operation:

* Kidney, lung, or liver disease
* Insulin-dependent diabetes with other organ dysfunction
* Life-threatening diseases unrelated to heart failure
* Vascular disease of the neck and leg arteries.
* High pulmonary vascular resistance
* Recent thromboembolism
* Age over 60 years (some variation between centres)
* Alcohol or drug abuse

Procedures


Pre-operative


A typical heart transplantation begins with a suitable donor heart being located from a recently deceased or brain dead donor. The transplant patient is contacted by a nurse coordinator and instructed to attend the hospital in order to be evaluated for the operation and given pre-surgical medication. At the same time, the heart is removed from the donor and inspected by a team of surgeons to see if it is in a suitable condition to be transplanted. Occasionally it will be deemed unsuitable. This can often be a very distressing experience for an already emotionally unstable patient, and they will usually require emotional support before being sent home. The patient must also undergo many emotional, psychological, and physical tests to make sure that they are in good mental health and will make good use of their new heart. The patient is also given immunosuppressant medication so that their immune system will not reject the new heart.

Operative

Schematic of a transplanted heart with native lungs and the great vessels.

Once the donor heart has passed its inspection, the patient is taken into the operating room and given a general anesthetic. Either an orthotopic or a heterotopic procedure is followed, depending on the condition of the patient and the donor heart.

Orthotopic procedure

The orthotopic procedure begins with the surgeons performing a median sternotomy to expose the mediastinum. The pericardium is opened, the great vessels are dissected and the patient is attached to cardiopulmonary bypass. The failing heart is removed by transecting the great vessels and a portion of the left atrium. The pulmonary veins are not transected; rather a circular portion of the left atrium containing the pulmonary veins is left in place. The donor heart is trimmed to fit onto the patients remaining left atrium and the great vessels are sutured in place. The new heart is restarted, the patient is weaned from cardiopulmonary bypass and the chest cavity is closed.

Heterotopic procedure

In the heterotopic procedure, the patient's own heart is not removed before implanting the donor heart. The new heart is positioned so that the chambers and blood vessels of both hearts can be connected to form what is effectively a 'double heart'. The procedure can give the patients original heart a chance to recover, and if the donor's heart happens to fail (eg. through rejection), it may be removed, allowing the patients original heart to start working again. Heterotopic procedures are only used in cases where the donor heart is not strong enough to function by itself (due to either the patients body being considerably larger than the donor's, the donor having a weak heart, or the patient suffering from pulmonary hypertension).

Post-operative

The patient is taken into ICU to recover. When they wake up, they will be transferred to a special recovery unit in order to be rehabilitated. How long they remain in hospital post-transplant depends on the patient's general health, how well the new heart is working, and their ability to look after their new heart. Doctors typically like the new recipients to leave hospitals soon after surgery because of the risk of infection in a hospital (typically 1 - 2 weeks without any complications). Once the patient is released, they will have to return to the hospital for regular check-ups and rehabilitation sessions. They may also require emotional support. The number of visits to the hospital will decrease over time, as the patient adjusts to their transplant. The patient will have to remain on lifetime immunosuppressant medication to avoid the possibility of rejection. Since the vagus nerve is severed during the operation, the new heart will beat at around 100 bpm until nerve regrowth occurs.

'Living organ' transplant


Doctors made medical history in February 2006, at Bad Oeynhausen Clinic for Thorax- and Cardiovascular Surgery, Germany, when they successfully transplanted a 'beating heart' into a patient.[7] Normally a donor's heart is injected with potassium chloride in order to stop it beating, before being removed from the donor's body and packed in ice in order to preserve it. The ice can usually keep the heart fresh for a maximum of four[8] to six hours with proper preservation, depending on its starting condition. Rather than cooling the heart, this new procedure involves keeping it at body temperature and hooking it up to a special machine called an Organ Care System that allows it to continue beating with warm, oxygenated blood flowing through it. This can maintain the heart in a suitable condition for much longer than the traditional method.

Prognosis

The prognosis for heart transplant patients following the orthotopic procedure has greatly increased over the past 20 years, and as of May 30, 2008, the survival rates were as follows.[9]

* 1 year: 87.5% (males), 85.5% (females)
* 3 years: 78.8% (males), 76.0% (females)
* 5 years: 72.3% (males), 67.4% (females)


In a November 2008 study conducted on behalf of the U.S. federal government by Dr. Eric Weiss of the Johns Hopkins University School of Medicine, it was discovered that heart transplants- all other factors being accounted for- work better in same-sex transplants (male to male, female to female). However, due to the present acute shortage in donor hearts, this may not always be feasible.

As of the end of 2007, Tony Huesman is the world's longest living heart transplant patient, having survived for 29 years with a transplanted heart. Huesman received a heart in 1978 at the age of 20 after viral pneumonia severely weakened his heart. The operation was performed at Stanford University under American heart transplant pioneer Dr. Norman Shumway, who continued to perform the operation in the U.S. after others abandoned it due to poor results.[10]. Another noted heart transplant recipient, Kelly Perkins, climbs mountains around the world to promote positive awareness of organ donation. Perkins is the first heart transplant recipient to climb to the peaks of Mt. Fuji, Mt. Kilimanjaro, the Matterhorn, Mt. Whitney, and Cajon de Arenales in Argentina in 2007, 12 years after her transplant surgery. Dwight Kroening is yet another noted recipient promoting positive awareness for organ donation. Twenty two years after his heart transplant, he is the first to finish an Ironman competition.[11] Fiona Coote was the second Australian to receive a heart transplant in 1984 (at age 14) and the youngest Australian. At 24 years since her transplant she is also a long term survivor and is involved in publicity and charity work for the red cross, and promoting organ donation in Australia.

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Renal Transplantation

Friday, April 24, 2009

Hepatic Transplantation

PROCEDURE OF THE DAY

Hepatic Transplantation

Liver transplantation or hepatic transplantation is the replacement of a diseased liver with a healthy liver allograft. The most commonly used technique is orthotopic transplantation, in which the native liver is removed and the donor organ is placed in the same anatomic location as the original liver. Liver transplantation nowadays is a well accepted treatment option for end-stage liver disease and acute liver failure.

History

The first human liver transplant was performed in 1963 by a surgical team led by Dr. Thomas Starzl[1] of Denver, Colorado, United States. Dr. Starzl performed several additional transplants over the next few years before the first short-term success was achieved in 1967 with the first one-year survival posttransplantation. Despite the development of viable surgical techniques, liver transplantation remained experimental through the 1970s, with one year patient survival in the vicinity of 25%.[2] The introduction of cyclosporine by Sir Roy Calne markedly improved patient outcomes, and the 1980s saw recognition of liver transplantation as a standard clinical treatment for both adult and pediatric patients with appropriate indications. Liver transplantation is now performed at over one hundred centres in the USA, as well as numerous centres in Europe and elsewhere. One year patient survival is 80-85%, and outcomes continue to improve, although liver transplantation remains a formidable procedure with frequent complications. Unfortunately, the supply of liver allografts from non-living donors is far short of the number of potential recipients, a reality that has spurred the development of living donor liver transplantation.

Indications


Liver transplantation is potentially applicable to any acute or chronic condition resulting in irreversible liver dysfunction, provided that the recipient does not have other conditions that will preclude a successful transplant. Metastatic cancer outside liver, active drug or alcohol abuse and active septic infections are absolute contraindications. While infection with HIV was once considered an absolute contraindication, this has been changing recently. Advanced age and serious heart, pulmonary or other disease may also prevent transplantation (relative contraindications). Most liver transplants are performed for chronic liver diseases that lead to irreversible scarring of the liver, or cirrhosis of the liver.

Techniques


Before transplantation liver support therapy might be indicated (bridging-to-transplantation). Artificial liver support like liver dialysis or bioartificial liver support concepts are currently under preclinical and clinical evaluation. Virtually all liver transplants are done in an orthotopic fashion, that is the native liver is removed and the new liver is placed in the same anatomic location. The transplant operation can be conceptualized as consisting of the hepatectomy (liver removal) phase, the anhepatic (no liver) phase, and the postimplantation phase. The operation is done through a large incision in the upper abdomen. The hepatectomy involves division of all ligamentous attachments to the liver, as well as the common bile duct, hepatic artery, hepatic vein and portal vein. Usually, the retrohepatic portion of the inferior vena cava is removed along with the liver, although an alternative technique preserves the recipient's vena cava ("piggyback" technique).

The donor's blood in the liver will be replaced by an ice-cold organ storage solution, such as UW (Viaspan) or HTK until the allograft liver is implanted. Implantation involves anastomoses (connections) of the inferior vena cava, portal vein, and hepatic artery. After blood flow is restored to the new liver, the biliary (bile duct) anastomosis is constructed, either to the recipient's own bile duct or to the small intestine. The surgery usually takes between five and six hours, but may be longer or shorter due to the difficulty of the operation and the experience of the surgeon.

The large majority of liver transplants use the entire liver from a non-living donor for the transplant, particularly for adult recipients. A major advance in pediatric liver transplantation was the development of reduced size liver transplantation, in which a portion of an adult liver is used for an infant or small child. Further developments in this area included split liver transplantation, in which one liver is used for transplants for two recipients, and living donor liver transplantation, in which a portion of a healthy person's liver is removed and used as the allograft. Living donor liver transplantation for pediatric recipients involves removal of approximately 20% of the liver (Couinaud segments 2 and 3).

Immunosuppressive management

Like all other allografts, a liver transplant will be rejected by the recipient unless immunosuppressive drugs are used. The immunosuppressive regimens for all solid organ transplants are fairly similar, and a variety of agents are now available. Most liver transplant recipients receive corticosteroids plus a calcinuerin inhibitor such as tacrolimus or Cyclosporin plus a antimetabolite such as Mycophenolate Mofetil.

Liver transplantation is unique in that the risk of chronic rejection also decreases over time, although recipients need to take immunosuppresive medication for the rest of their lives. It is theorized that the liver may play a yet-unknown role in the maturation of certain cells pertaining to the immune system. There is at least one study by Dr. Starzl's team at the University of Pittsburgh which consisted of bone marrow biopsies taken from such patients which demonstrate genotypic chimerism in the bone marrow of liver transplant recipients.

Graft Rejection


After a liver transplantation, there are three types of graft rejection that may occur. They include hyperacute rejection, acute rejection and chronic rejection. Hyperacute rejection is caused by preformed anti-donor antibodies. It is characterized by the binding of these antibodies to antigens on vascular endothelial cells. Complement activation is involved and the effect is usually profound. Hyperacute rejection happens within minutes to hours after the transplant procedure. Unlike hyperacute rejection, which is B cell mediated, acute rejection is mediated by T cells. It involves direct cytotoxicity and cytokine mediated pathways. Acute rejection is the most common and the primary target of immunosuppressive agents. Acute rejection is usually seen within days or weeks of the transplant. Chronic rejection is the presence of any sign and symptom of rejection after 1 year. The cause of chronic rejection is still unknown but an acute rejection is a strong predictor of chronic rejections. Liver rejection may happen anytime after the transplant. Lab findings of a liver rejection include abnormal AST, ALT, GGT and liver function values such as prothrombin time, ammonia level, bilirubin level, albumin concentration, and blood glucose. Physical findings include encephalopathy, jaundice, bruising and bleeding tendency. Other nonspecific presentation are malaise, anorexia, muscle ache, low fever, slight increase in white blood count and graft tender.

Results

Prognosis is quite good. However, those with certain illnesses may differ. [3] There is no exact model to predict survival rates; however, those with transplant have a 58% chance of surviving 15 years. [4] Failure from the new liver occurs in 10% to 15% of all cases. These percentages are contributed by many complications. Early graft failure is probably due to preexisting disease of the donated organ. Others include technical flaws during surgery such as revascularization that may lead to nonfunctioning graft.

Living donor transplantation

Living donor liver transplantation (LDLT) has emerged in recent decades as a critical surgical option for patients with end stage liver disease, such as cirrhosis and/or hepatocellular carcinoma often attributable to one or more of the following: long-term alcohol abuse, long-term untreated Hepatitis C infection, long-term untreated Hepatitis B infection. The concept of LDLT is based on (1) the remarkable regenerative capacities of the human liver and (2) the widespread shortage of cadaveric livers for patients awaiting transplant. In LDLT, a piece of healthy liver is surgically removed from a living person and transplanted into a recipient, immediately after the recipient’s diseased liver has been entirely removed.

Historically, LDLT began as a means for parents of children with severe liver disease to donate a portion of their healthy liver to replace their child's entire damaged liver. The first report of successful LDLT was by Dr. Silvano Raia at the Universidade de São Paulo (USP) Medical School in 1986. Surgeons eventually realized that adult-to-adult LDLT was also possible, and now the practice is common in a few reputable medical institutes. It is considered more technically demanding than even standard, cadaveric donor liver transplantation, and also poses the ethical problems underlying the indication of a major surgical operation (hepatectomy) on a healthy human being. In various case series the risk of complications in the donor is around 10%, and very occasionally a second operation is needed. Common problems are biliary fistula, gastric stasis and infections; they are more common after removal of the right lobe of the liver. Death after LDLT has been reported at 0% (Japan), 0.3% (USA) and <1% (Europe), with risks likely to improve further as surgeons gain more experience in this procedure.[5]

In a typical adult recipient LDLT, 55% of the liver (the right lobe) is removed from a healthy living donor. The donor's liver will regenerate to 100% function within 4-6 weeks and will reach full volumetric size with recapitulation of the normal structure soon thereafter. It may be possible to remove 70% to 75% of the liver from a healthy living donor without harm in most cases. The transplanted portion will reach full function and the appropriate size in the recipient as well, although it will take longer than for the donor.

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Cardiac Transplantation

Thursday, April 23, 2009

Duodenal Switch

PROCEDURE OF THE DAY

Duodenal Switch

The Duodenal Switch (DS) procedure, also known as Biliopancreatic Diversion with Duodenal Switch (BPD-DS) or Gastric Reduction Duodenal Switch (GRDS), is a weight loss surgery procedure that is composed of a restrictive and a malabsorptive aspect.

The restrictive portion of the surgery involves removing approximately 70% of the stomach along the greater curvature.

The malabsorptive portion of the surgery reroutes a lengthy portion of the small intestine, creating two separate pathways and one common channel. The shorter of the two pathways, the digestive loop, takes food from the stomach to the common channel. The much longer pathway, the biliopancreatic loop, carries bile from the liver to the common channel. The common channel is the portion of small intestine, usually 75-150 centimeters long, in which the contents of the digestive path mix with the bile from the biliopancreatic loop before emptying into the large intestine. The objective of this arrangement is to reduce the amount of time the body has to capture calories from food in the small intestine and to selectively limit the absorption of fat. As a result, following surgery, these patients only absorb approximately 20% of the fat they intake.


Comparison to other surgeries


Advantages

The primary advantage of Duodenal Switch (DS) surgery is that its combination of moderate intake restriction with substantial calorie malabsorption results in a very high percentage of excess weight loss for obese individuals, with a very low risk of significant weight regain.[2]

Type 2 diabetics have had a 98% "cure" [3] (i.e. became euglycemic) almost immediately following surgery which is due to the metabolic effect from the intestine switch. The results are so favorable that some surgeons in Europe are performing the "switch" or intestinal surgery on non-obese patients for the benefits of curing the diabetes.[citation needed]

The following observations were reported on the resolution of obesity related comorbidities following the Duodenal Switch: type 2 diabetes 99%, hyperlipidemia 99%, sleep apnea 92%, and hypertension 83%. [4]

Because the pyloric valve between the stomach and small intestine is preserved, people who have undergone the DS do not experience the dumping syndrome common with people who've undergone the Roux-en-Y gastric bypass surgery (RNY). Much of the production of the hunger hormone, ghrelin, is removed with the greater curvature of the stomach.

Diet following the DS is more normal and better tolerated than with other surgeries. [5]

The malabsorptive component of the DS is fully reversible as no small intestine is actually removed, only re-routed.

Disadvantages

The malabsorptive element of the DS requires that those who undergo the procedure take vitamin and mineral supplements above and beyond that of the normal population, as do patients having the RNY surgery. Commonly prescribed supplements include a daily multivitamin, calcium citrate, and the fat-soluble vitamins A, D, E and K.

Because gallstones are a common complication of rapid weight loss following any type of weight loss surgery, some surgeons may remove the gall bladder as a preventative measure during the DS or the RNY. Others prefer to prescribe medication to reduce the risk of post-operative gallstones.

Far fewer surgeons perform the DS compared to other weight loss surgeries because it is a more difficult one to learn compared to RNY and Lap Band procedures.

Like RNY patients, DS patients require lifelong and extensive blood tests to check for deficiencies in life critical vitamins and minerals. Without proper follow up tests and lifetime supplementation RNY and DS patients can become ill. This follow-up care is non-optional and must continue for as long as the patient lives.

The restrictive portion of the DS is not reversible, since part of the stomach is removed. However, the stomach in all DS patients does expand over time and while it will never reach the same size as the natural stomach, some reversal by stretching always occurs.

Risks


All surgical procedures involve a degree of risk however this must be balanced against the significant risks associated with severe obesity.

Some of the surgical risks or complications for this procedure are: perforation involving small bowel, duodenum, or stomach causing a leak, infection, abscess, deep vein thrombosis (blood clot), and pulmonary emboli (blood clot traveling to the lungs).

Longer term risks include hernia and bowel obstruction.

Malnutrition is an uncommon and preventable risk after Duodenal Switch. [6]

Qualifications

The National Institutes of Health state that if you meet the following guidelines[7], weight loss surgery may be an appropriate measure for permanent weight loss:

* BMI of 40 or over
* BMI of 35 or over with obesity-related illnesses such as:
o Diabetes mellitus type 2
o Coronary heart disease
o Sleep apnea
o Osteoarthritis
* An understanding of the operation and lifestyle changes necessary following the surgery.

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Hepatic Transplantation

Wednesday, April 22, 2009

Puestow Procedure

PROCEDURE OF THE DAY

Puestow procedure

The Puestow procedure (also known as a Puestow-Gillesby procedure, or a pancreaticojejunostomy) is a surgical technique used in the treatment of chronic pancreatitis. It involves the surgical formation of an artificial passage connecting the pancreas to the jejunum.[1]

Technique

The operation involves creating a longitudinal incision along the pancreas while the main pancreatic duct is filleted open longitudinally from the head of the organ to its tail. The duct and pancreas are then attached to a loop of the small intestine (pancreaticojejunostomy), which is oversewn to the exposed pancreatic duct in order to allow its drainage. When used in the appropriate setting, pain from chronic pancreatitis can improve. One advantage of this procedure compared to a Frey's procedure is that pancreatic tissue is preserved, which may be of critical importance in patients with exocrine or endocrine insufficiency from their chronic pancreatitis.

Indications


A Puestow procedure is indicated for the treatment of symptomatic chronic pancreatitis patients with pancreatic ductal obstruction and a dilated main pancreatic duct. The main pancreatic duct needs to be 6mm in diameter in the body of the pancreas for this procedure to be possible.

Limitations

One of the problems that can lead to failure of the Puestow procedure is that pain can persist due to failure to drain the pancreatic duct on the head of the pancreas. A Frey's procedure is an alternative surgical procedure to the Puestow that allows for better drainage of the head, but pancreatic tissue is removed.

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Tuesday, April 21, 2009

Endoscopic Retrograde Cholangiopancreatography

PROCEDURE OF THE DAY

Endoscopic Retrograde Cholangiopancreatography

Endoscopic retrograde cholangiopancreatography (ERCP) is a technique that combines the use of endoscopy and fluoroscopy to diagnose and treat certain problems of the biliary or pancreatic ductal systems. Through the endoscope, the physician can see the inside of the stomach and duodenum, and inject dyes into the ducts in the biliary tree and pancreas so they can be seen on x-rays.

ERCP is used primarily to diagnose and treat conditions of the bile ducts, including gallstones, inflammatory strictures (scars), leaks (from trauma and surgery), and cancer. ERCP can be performed for diagnostic and therapeutic reasons, although the development of safer and relatively non-invasive investigations such as magnetic resonance cholangiopancreatography (MRCP) and endoscopic ultrasound has meant that ERCP is now rarely performed without therapeutic intent.

Diagnostic

* Obstructive jaundice - This may be due to several causes
* Chronic pancreatitis - a now controversial indication due to widespread availability of safer diagnostic modalities including endoscopic ultrasound, high-resolution CT, and MRI/MRCP
* Gallstones with dilated bile ducts on ultrasonography
* Bile duct tumors
* Suspected injury to bile ducts either as a result of trauma or iatrogenic
* Sphincter of Oddi dysfunction
* Pancreatic tumors no longer represent a valid diagnostic indication for ERCP unless they cause bile duct obstruction and jaundice. Endoscopic ultrasound represents a safer and more accurate diagnostic alternative

Therapeutic

* Any of the above when the following may become necessary
o Endoscopic sphincterotomy (both of the biliary and the pancreatic sphincters)
o Removal of stones
o Insertion of stent(s)
o Dilation of strictures (e.g. primary sclerosing cholangitis, anastomotic strictures after liver transplantation)

Contraindications

1. Absolute contraindication:
* The uncooperative patient.
2. Relative contraindications
* Recent attack of acute pancreatitis, within the past several weeks.
* Recent myocardial infarction.
* Inadequate surgical back-up
* History of contrast dye anaphylaxis
* Poor health condition for surgery.
* Severe cardiopulmonary disease.

Procedure

The patient is sedated or anaesthetized. Then a flexible camera (endoscope) is inserted through the mouth, down the esophagus, into the stomach, through the pylorus into the duodenum where the ampulla of Vater (the opening of the common bile duct and pancreatic duct) exists. The sphincter of Oddi is a muscular valve that controls the opening of the ampulla. The region can be directly visualized with the endoscopic camera while various procedures are performed. A plastic catheter or cannula is inserted through the ampulla, and radiocontrast is injected into the bile ducts, and/or, pancreatic duct. Fluoroscopy is used to look for blockages, or other lesions such as stones.

When needed, the opening of the ampulla can be enlarged with an electrified wire (sphincterotome) and access into the bile duct obtained so that gallstones may be removed or other therapy performed.

Other procedures associated with ERCP include the trawling of the common bile duct with a basket or balloon to remove gallstones and the insertion of a plastic stent to assist the drainage of bile. Also, the pancreatic duct can be cannulated and stents be inserted. The pancreatic duct requires visualisation in cases of pancreatitis.

In specific cases, a second camera can be inserted through the channel of the first endoscope. This is termed duodenoscope-assisted cholangiopancreatoscopy (DACP) or mother-daughter ERCP. The daughter scope can be used to administer direct electrohydraulic lithotripsy to break up stones, or to help in diagnosis by directly visualizing the duct (as opposed to obtaining X-ray images).[1]

Risks

The major risk of an ERCP is the development of pancreatitis, which can occur in up to 5% of all procedures. This may be self limited and mild, but may require hospitalization, and rarely, may be life-threatening. Patients at additional risk for pancreatitis are younger patients, patients with previous post-ERCP pancreatitis, females, procedures that involve cannulation or injection of the pancreatic duct, and patients with sphincter of Oddi dysfunction.[2]

Gut perforation is a risk of any endoscopic procedure, and is an additional risk if a sphincterotomy is performed. As the second part of the duodenum is anatomically in a retroperitoneal location (that is, behind the peritoneal structures of the abdomen), perforations due to sphincterotomies are also retroperitoneal. Sphincterotomy is also associated with a risk of bleeding.[2]

Oversedation can result in dangerously low blood pressure and nausea and vomiting.

There is also a risk associated with the contrast dye in patients who are allergic to compounds containing iodine.

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Puestow Procedure