Study Confirms Safety of Living Donor Nephrectomy

From Medscape Transplantation
Viewpoints
Study Confirms Safety of Living Donor Nephrectomy

Posted 03/12/2009

Robert J. Stratta, MD

Ibrahim HN, Foley R, Tan L, et al
N Engl J Med. 2009;360:459-469

Summary

From 1963 through 2007, a total of 3698 nephrectomies in living donors were performed at a single center. Ibrahim and colleagues performed a retrospective analysis to determine the vital status and lifetime risk for end-stage renal disease (ESRD) in all donors.

From 2003 through 2007, a subset of 255 donors also underwent measurement of glomerular filtration rate (GFR) and urinary albumin excretion and were assessed for the prevalence of hypertension, general health status, and quality of life using the Short Form (SF)-36.

Overall, 268 donors (7.2%) died (30% due to cardiovascular disease), which was believed to be comparable to the death rate in the general population. A total of 11 donors (estimated incidence: 180 per million persons per year) developed ESRD at a mean of 22.5 years following kidney donation, which was believed to be less than the incidence of ESRD in the general population (overall adjusted incidence rate: 268 per million persons per year). Of the 255 donors who underwent a more comprehensive assessment at a mean of 12.2 years after kidney donation, the mean serum creatinine level was 1.1 mg/dL (compared with 0.9 mg/dL preoperatively) and the estimated GFR was 63.7 mL/min (compared with 84 mL/min preoperatively), which represented a 20% to 25% decline in renal function over time.

Only 1.2% of the 255 donors had macroalbuminuria, and none had an estimated GFR < 30 mL/min. A total of 63/255 donors (24.7%) were being treated with antihypertensive medication, including 19 (7.5%) with newly diagnosed hypertension. Overall health status in the 255 donors was as good as, if not better than, 255 matched controls. Quality of life, including physical- and mental-health summary scores, was significantly (P < .001) above the US population norms for both comparisons.

On the basis of these results, the authors concluded that lifespan, health status, and quality of life are not adversely affected by unilateral nephrectomy in carefully screened kidney donors.
Viewpoint

This seminal report is one of the largest and most comprehensive studies to date to examine the long-term outcomes and confirm the safety of the living donor nephrectomy procedure in appropriately selected donors. Potential donors did not have diabetes, albuminuria, or hypertension; had a GFR > 80 mL/min; and were free from liver disease, active infections, and any systemic illnesses. Many of the donors in this study were followed for 20-30 years.

Although it is not surprising that carefully screened donors would have lower mortality rates and improved health-related quality of life compared with the general population, it is reassuring that renal function was preserved and rates of ESRD were low following uninephrectomy. However, it is important to note the age and socioeconomic makeup of the most recent cohort of 255 donors who were studied more intensely: The majority (99%) were white, 62% were women, and the mean age at donation was 41 years. It is well established that nephron mass, overall kidney function, and the capacity for compensatory hypertrophy decline with age. In addition, chronic kidney disease tends to be more prevalent and progress more rapidly in other ethnic groups. Moreover, the influence of mild hypertension and obesity remains uncertain when evaluating prospective candidates for kidney donation.

Overall, studies of former kidney donors have revealed excellent long-term outcomes in regard to donor health when compared with the general population. However, previous studies have important limitations that preclude extrapolation of these results to all populations. Studies performed in Europe have included only persons of northern European descent. Studies in the United States have been limited by incomplete follow-up and are mostly restricted to younger white persons residing in the North. Outcomes in kidney donors from racial and ethnic minority groups, many of whom bear a disproportionate burden of kidney disease, have not been described in detail, and preliminary studies have yielded conflicting results.

Blacks comprise approximately 12% of the US population but account for approximately one third of patients with ESRD in the United States. Familial clustering of kidney disease, regardless of etiology, has been demonstrated in black families. Blacks with a first-degree relative with ESRD are 9 times more likely to develop ESRD than are whites with a first-degree relative with ESRD. Although black kidney donors appear to assume more risk than white donors do, outcomes in black kidney donors are not well described.

It is not known whether the individuals studied had medical insurance or access to healthcare. All kidney donors, particularly those from higher-risk populations, would benefit from long-term medical follow-up because the long-term outcomes of donation have not been delineated clearly in all racial and ethnic groups. Discrimination from insurance companies as a result of kidney donation may result in decreased access to healthcare and delay in recognition of treatable health problems, such as hypertension. Protecting the insurability of donors and providing adequate medical and quality-of-life follow-up after donation would be appropriate given the heroic and voluntary nature of the donation process.

http://www.medscape.com/viewarticle/588975