Evaluation and Patient Selection for Kidney Transplantation
There is no single profile that describes the potential candidate for kidney transplantation. The only consistent variable is ESRD, actual or fast approaching. Patient responses to ESRD vary according to physiologic and psychological adaptation to illness, and depend on the length of time a patient has carried the diagnosis of ESRD and/or been on dialysis. One patient may have complete functionality on peritoneal or home hemodialysis, experience only occasional periods of low energy, and be employed. Another patient may experience severe, disabling symptoms while on dialysis. The complexion may be sallow as a result of urochrome deposits in the skin. The patient may complain of lethargy or lack of energy and inability to walk short distances or climb stairs without exhaustion or shortness of breath, due to anemia cause by altered production of erythropoietin. Some patients complain about complex medication regimens, dialysis schedules, dietary restrictions, and dependency issues. Some express anxiety about financial issues and others about frustrations related to their desire to have children. In general, patients choose the option of transplantation out of a desire for more normalcy in their lives.
Treatment options for patients with ESRD include palliative care, hemodialysis, peritoneal dialysis, and kidney transplantation. The focus of this chapter is kidney transplantation. The most basic criterion for acceptance for kidney transplantation is a good probability for survival. During the pretransplant evaluation, patients are categorized as low, moderate, or high risk based on surgical risk factors and comorbid medical conditions. Absolute and relative contraindications to kidney transplantation are listed in Table 3 . Absolute contraindications include some types of neoplastic disease, HIV infection, AIDS, some infectious processes, some systemic diseases, and irreversible vital organ failure. However, due to special expertise and/or research protocols at individual centers, patients with these contraindications may be transplanted, but this is not reflective of current practice standards.
The pretransplant evaluation usually takes place in an outpatient setting. The transplant evaluation begins when a patient is referred to the transplant program, usually from a community nephrologist, internist, or primary care physician. Evaluation for transplantation is a complex and time-consuming process. A tremendous amount of information must be collected, reviewed, analyzed, and synthesized in a cost-effective manner. To that end, clinical practice guidelines can be helpful.
Comprehensive clinical practice guidelines for the evaluation of kidney transplant candidates, developed by a subcommittee of the Clinical Practice Guidelines Committee of the American Society of Transplantation, were recently published.[18,19] These guidelines were designed for use by physicians and other transplant professionals to facilitate the evaluation of potential kidney transplant candidates, with the acknowledgment that each candidate is different and faces a unique set of biopsychosocial challenges.
A multidisciplinary team of transplant surgeons, nephrologists, nurses, social workers, nutritionists, and financial coordinators form the core group that evaluates the patient. A transplant coordinator (usually a nurse) with expertise in the evaluation process coordinates the pretransplant evaluation. The main function of the transplant coordinator is to facilitate the referral consultation process, oversee the evaluation, present findings of the evaluation to the transplant team, and follow through with the team's recommendations. In some cases, the pretransplant coordinator is also responsible for coordinating the evaluation of a live donor.
The evaluation of potential kidney transplant recipients is designed to meet the needs of patients and the transplant program. For patients, the process should include opportunities for information and education necessary for informed consent and decision making. In addition, the transplant team must consider potential benefits and risks to determine what is in the best interest of the patient.
Initially, preliminary information (ie, information to determine financial feasibility) is collected from and shared with the patient and family (ie, risks and benefits). In addition, attempts should be made to identify obvious barriers to transplantation such as ischemic heart disease or substance abuse. Evaluation for kidney transplantation is expensive. Therefore, it is important to rule out unsuitable patients early in the process, before proceeding with the full evaluation. Patients with ESRD who are transplanted live longer than patients who are not transplanted, so in addition to routine histories, physical examination, and diagnostic tests, screening tests for conditions such as cancer and osteoporosis are indicated.
Despite the time involved in eliciting a thorough medical history, this information is vital to the transplant team in determining the candidate's risk profile and provides direction for the remainder of the evaluation. Information to elicit in the medical history includes vital signs; original disease that led to renal failure, including biopsy history and reports; urologic disease; dialysis history; past medical history from the referring physician; history of cardiovascular and neoplastic disease; pregnancy history; current medications; previous transfusions; and previous transplantation. It is important to know the family history of ESRD, cardiovascular disease (including hypertension), cancer, diabetes mellitus, and liver disease to identify potential hereditary risk factors.
The past surgical history includes a list of previous surgical procedures and dates and locations performed. A standardized tool (Figure 1) designed to collect pertinent information related to the patient's history ensures efficiency and reliability of the data and information.
Figure 1.
Pretransplant evaluation history and evaluation form.
Figure 1.
Pretransplant evaluation history and evaluation form.
Figure 1.
Pretransplant evaluation history and evaluation form.
Figure 1.
Pretransplant evaluation history and evaluation form.
The transplant social worker and transplant coordinator collaborate to collect information related to cognitive, behavioral, and financial factors that will be either assets or liabilities to the candidate and the family and social issues that may affect medical outcomes; for example -- information related to education, current and previous employment and occupations, disability status, substance abuse (current and past use of alcohol, drugs, or tobacco), activity level (ie, active or sedentary), and history of adherence to the medical prescriptions. From interactions with the candidate and family members, stress level, coping mechanisms, family dynamics, and perceived value of transplantation can be determined to predict the impact that transplantation will have on the patient and family.
Many centers have financial specialists who assist patients with insurance coverage and billing issues. Determining adequate pre- and posttransplant hospitalization costs, medication coverage, and additional services is necessary to avoid a financial crisis later on.
The physical examination follows the standard format of assessment of HEENT, extremities, and cardiovascular, abdomen and GI, and neurologic systems. In many cases, however, the patient has had a recent physical examination by the referring physician, which allows the transplant team to focus on the cardiovascular system to determine abnormalities, comorbidities, and surgical risk. Assessment of the iliac arteries for decreased pulses or bruits is particularly important to determine whether blood flow to the legs will be compromised after the renal allograft is implanted. In addition, a comprehensive review of systems (Figure 1) provides important information about vital organ function, potential sources of infection, signs and symptoms requiring further assessment, and need for age-appropriate health screening.
The majority of diagnostics tests are performed at the time of the initial referral; however, as results of these tests are known, additional tests such as viral serologies (HIV, hepatitis, cytomegalovirus, Epstein-Barr) may be ordered. If age- and sex-appropriate primary health screening tests (ie, Pap smear, mammogram, prostate specific antigen, occult blood in stool) have not been done, these tests are added to the evaluation.
The success of kidney transplantation depends on the recipient's immunologic acceptance of a nonself or foreign graft. One means of facilitating this is for the kidney donor and recipient to be histocompatible, thereby minimizing genetic disparity. The 2 major antigen systems for transplantation in man, the ABO system and the human leukocyte antigen (HLA) system, are discussed in detail in Chapter 2: Immunologic Aspects of Organ Transplantation.
During the evaluation, blood tests are done to determine the candidate's genetic type. This typing is often referred to as tissue typing or HLA typing. A mixed leukocyte culture (MLC) is done at some centers with recipient and live donor sera in culture to determine HLA identity and genetic disparity specific to the HLA D-DR locus. Lymphocytes exposed to nonidentical HLA antigens respond by increased stimulation, DNA synthesis, and blast formation. If blastogenesis occurs within 5-7 days of the incubation period, the donor and recipient are considered to be incompatible. Because of the length of time required to obtain confirmatory results, the MLC is done only in cases of live donor transplantation. Because of the time it takes to perform this culture, some centers are using the flow cross-match procedure to determine the B cell reactivity between donor and recipient.
Immediately before cadaveric transplantation and as part of the initial testing for live donor transplantation, a white blood cell cross-match (T cell cross-match) is done. Donor lymphocytes are exposed to recipient sera to detect the presence of preformed circulating cytotoxic antibodies to donor antigens. A positive cross-match precludes transplantation from that particular donor because the result would be hyperacute rejection.
Once the transplant candidate evaluation is completed, the data and information are summarized (Figure 2) and presented to an evaluation committee, where a decision is made to accept or not accept the patient for transplantation. Decisions regarding additional diagnostic tests, donor options, and psychosocial issues are addressed at this time, and the committee may decide that further information is required before a final decision can be made. If live donation is an option, the live donor evaluation is reviewed as well. Accepted candidates are either listed with the United Network for Organ Sharing (UNOS) or surgery is scheduled for live donation and elective transplantation. If a patient is registered on the UNOS waiting list for cadaveric donation, blood is regularly (ie, monthly) sent to the transplant center to detect current levels of reactive antibodies.
Figure 2.
Pretransplant summary form.
Pretransplant summary form.
The kidney transplant recipient has 2 potential sources of a kidney donor, the cadaveric donor and the live donor. Therefore, a discussion of donor options is part of the evaluation. The criteria for cadaveric transplantation are outlined by the UNOS.[11] In light of the ongoing cadaveric donor shortage, many centers encourage live donation to prevent extended periods on dialysis and have procedures in place to assist patients with approaching family members or friends about donating a kidney. The longer patients remain on dialysis, the more difficult it is to reintroduce the patient to employment.[20-22]
Organ Transplant © 2002 Medscape
Cite this: Rebecca P. Winsett, Judy C. Martin, Laura Reed. Kidney Transplantation - Medscape - Oct 01, 2002.
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