CHAPTER 58 Organ Transplantation
OVERVIEW OF TRANSPLANTATION
Societal mores also impose limitations. The scarcity of cadaveric organs creates a mismatch between the number of patients who need transplantation and the number who can undergo transplantation. Currently, there are over 93,000 persons on the waiting list for a solid organ transplantation, but only 17,000 transplants were done between January and July of 2006.1 Some European countries follow the doctrine of “presumed consent” for postmortem donation, but the United States does not. In recent years, transplant centers have attempted to expand the donor pool by harvesting organs from persons who have been declared dead secondary to cardiac arrest (i.e., non–heart-beating donors) in addition to harvesting organs from persons who have been declared dead by neurological criteria (i.e., brain death). In response to this problem, the Institute of Medicine (IOM) created a committee to study ways in which the supply of transplantable organs can be increased. The committee’s report, released in May 2006, recommended the following: vigorous public education about organ donation; provision of more opportunities for registration as an organ donor; easier access to state donor registries; and renewed attention to improvement of organ procurement systems.2
Organ donation by living donors is an increasingly important potential source of transplantable kidneys, livers, and lungs. This is especially true in Japan where there are no defined criteria for determination of brain death and therefore few cadaveric organs are available for harvest.3 In the United States, living donors may be related to the recipient; unrelated but emotionally connected; or anonymous, altruistic strangers. In 2006, 4,252 transplanted kidneys came from deceased donors and 3,751 kidney transplants came from live donors. Parent-to-child liver transplantation (of the left lateral lobe) is an option, as is adult-to-adult transplantation of the right hepatic lobe. Living-lung donation is also an option for carefully selected candidates, but it requires a lower lobe from two different donors for each single potential recipient. The source of the donated organ, that is, from a deceased donor or living donor, does not affect recipient outcome.
Living organ donation raises several ethical questions: for example, “What is true informed consent regarding both short- and long-term risks for the donor?” and “Is the donor’s offer (be it from an emotionally connected or unrelated person) truly voluntary?” It is difficult to determine what level of risk is acceptable for a healthy, altruistic donor.4
Several retrospective studies of the long-term medical and psychological sequelae in living organ donors have been conducted. Short-term risks for live kidney donors include the morbidity secondary to surgery and anesthesia (e.g., bleeding and infection) and salary loss during the weeks of recovery. For kidney donors, long-term health risks include the development of microalbuminuria and the potential for renal failure in the remaining kidney. Approximately 0.1% of live kidney donors in the United States have been placed on the waiting list for a kidney transplant.5 To date, no deaths have resulted from living lobar lung donation, but donors do lose 15% to 20% of their total lung volume and often experience a decrease in exercise capacity.6 Adult-to-adult liver donation carries a significant degree of morbidity, and mortality rate estimates approach 1%. As of March 2003, there have been seven deaths among live partial-liver donors. In addition, two adult donors have required liver transplantation. This procedure is currently under investigation by the National Institute of Health (NIH) and the American College of Transplant Surgeons. Recent literature suggests that right lobectomy in a donor is less risky if the remnant liver volume is greater than 35% of the total liver volume.7 The long-term effects of giving up over half of one’s total liver volume are still unknown.
In the United States, the United Network for Organ Sharing (UNOS), a nonprofit organization, endowed by Congress but reporting to the Department of Health and Human Services, regulates the allocation and distribution of donor organs. UNOS has two branches: the Organ Procurement and Transplant Network (OPTN) and the Scientific Registry. The OPTN divides the country into 11 distinct geographical regions, and each region has its own waiting list. The length of time spent on the waiting list can differ among regions. Determination of priority is organ specific. For kidneys, the length of time on the waiting list is the primary determining factor, although full human leukocyte antigen (HLA) compatibility confers priority. Pediatric recipients (those patients age 12 and under) for kidneys and livers take priority over adults. The Lung Allocation Score (LAS) is a calculated score for patients over 12 years of age that represents severity of illness and the likelihood of a successful transplant outcome. That score, in addition to blood type and distance from the hospital where the donor organs are located, determines waiting-list placement for potential lung transplantation recipients. The Model for End-Stage Liver Disease (MELD) is also a calculated score that predicts how urgently a patient over 12 years of age will need a transplant within the next 3 months. The only exception to the MELD system is a special category known as “Status 1.” Status 1 patients have suffered acute hepatic failure and might die within hours or days without a transplant. Tables 58-1 and 58-2 list the LAS and MELD criteria.
Diagnosis Age Body mass index (BMI) Presence of diabetes New York Heart Classification of functional status Distance walked in 6 minutes Forced vital capacity (FVC) Pulmonary artery pressure (PAP) Pulmonary capillary wedge pressure (PCWP) Creatinine Continuous oxygen requirement Requirement for ventilatory support |
* Adapted from United Network for Organ Sharing (UNOS): www.unos.org.
Bilirubin (BR) Prothrombin time (international normalized ratio [INR]) Creatinine |
Score ranges from 6-40 Represents urgency for need of transplant within 3 months of calculation |
* Adapted from United Network for Organ Sharing (UNOS): www.unos.org.
PSYCHIATRIC EVALUATION OF THE TRANSPLANT PATIENT
Pretransplant Psychiatric Evaluation
There are no universally accepted guidelines for the psychiatric evaluation of potential candidates for organ transplanta tion and little reliable or predictive data regarding “suitability for transplantation.” Some centers routinely offer a face-to-face clinical interview with a mental health provider, whereas other centers administer formal psychological testing or offer a structured or semistructured interview. Transplant centers differ in their determination of who is an “acceptable” candidate and what degree of risk they are willing to assume. Common psychosocial and behavioral exclusion criteria include active substance abuse, active psychotic symptoms, suicidal ideation (with intent or plan), dementia, or a felony conviction. Relative contraindications include poor social supports with inability to arrange for pretransplant or posttransplant care, personality disorders that interfere with a working relationship with a transplant team, nonadherence to a medication regimen, and neurocognitive limitations8 (Table 58-3).
Absolute Active substance abuse Active psychotic symptoms that interfere with function Suicidal ideation with intent or plan Dementia |
Relative Poor social supports Personality disorders that cause interpersonal difficulties with members of the transplant team Nonadherence to medication regimen or to recommendations for procedures |