Transplantation using marginal living donors

Bariatric surgery in prospective obese living kidney donors: scoping review and management decision algorithm

INTRODUCTION

Global chronic kidney disease is now epidemic, with substantial health and economic consequences. While scientific support for living donor renal transplants (LDRT) is strong, donor shortages necessitate consideration of expanded criteria, including obese individuals. Bariatric surgery (BS) may mitigate obesity-related risks, but research on living donor candidates is scarce. Our scoping review aims to compile evidence, identify gaps, and formulate an algorithm to guide healthcare professionals in evaluating BS for obese living donors.

EVIDENCE ACQUISITION

We did a systematic search of studies on living kidney donors and obesity. We searched the MEDLINE Ovid, Embase Ovid, CENTRAL and Web of Science databases for studies from database inception to March 30, 2023. All English-language articles available in full text have been considered. Excluded are commentaries, editorials, letters, and abstracts.

EVIDENCE SYNTHESIS

Obesity in LDRT raises long-term ESRD risk. Current high BMI donor admission raises ethical and clinical concerns. Encouraging timely weight loss can make obese candidates suitable donors, reducing risks. Sleeve gastrectomy is the most reported and preferable approach, since it minimizes hyperoxaluria risk. Re-evaluation for donation is possible 6-12 months post-BS, with BMI<35 for three months. Cost-benefit analysis favors BS over nephrectomy in obese donors (cost-benefit ratio: 3.64) when graft survival is equal.

CONCLUSIONS

BS shows promise with short-term effectiveness and potential long-term outcomes. However, it should not be perceived as a means to expand the donor pool but rather as a personalized approach to address obesity and improve individuals' health.

Hypertension and obesity in living kidney donors

Over the past few decades, the shortage in the kidney donor pool as compared to the increasing number of candidates on the kidney transplant waitlist led to loosening of kidney donors' acceptance criteria. Hypertension and obesity represent risk factors for chronic kidney disease, both in native kidneys and those in kidney transplant recipients. While great progress has been made in kidney transplantation from living donors to benefit the recipient survival and quality of life, progress has been slow to fully risk-characterize the donors. This review critically reassesses the current state of understanding regarding the risk of end-stage kidney disease in those donors with obesity, hypertension or both. Accurate risk assessment tools need to be developed urgently to fully understand the risk glomerular filtration rate compensation failure in the remaining kidney of the donors.

Clinical Impact of a Protocolized Kidney Donor Follow-up System

BACKGROUND

Adequate kidney donor management after donation is increasingly emphasized due to concerns of renal function impairment after nephrectomy with increasing life expectancy. In this study, the clinical impact of a protocolized kidney donor follow-up system by nephrologists was evaluated.

METHODS

A total of 427 living kidney donors underwent nephrectomy from January 2010 to December 2014 and were followed for at least 2 years at the Samsung Medical Center. Donors were followed-up by nephrologists after the establishment of a donor clinic with systemized protocols in January 2013. The primary outcomes were incidence of post-donation low estimated glomerular filtration rate (eGFR) and renal function adaptability. Secondary outcomes were changes in compliance and incidence of hyperuricemia and microalbuminuria.

RESULTS

The patients were divided into 2 groups according to the time of nephrectomy: the pre-donor clinic period (n = 182) and the donor clinic period (n = 172). Preoperative eGFR in patients in the pre-donor clinic period was higher than that in patients in the donor clinic period. After donation, poor renal adaptation was less frequent in the donor clinic period compared to the pre-donor clinic period. Low eGFR tended to be less common during the donor clinic period. Shorter mean outpatient clinic visit intervals with more visits within 6 months after donation and earlier detection of de novo hyperuricemia were found during the donor clinic period.

CONCLUSION

A protocolized donor clinic run by nephrologists may improve post-nephrectomy renal outcomes and compliance and facilitate better management of potential risk factors of chronic kidney disease in donors.

Suggestions on how to make suboptimal kidney transplantation an ethically viable option

To overcome kidney donation, the pool of potentially eligible donors has been widened by using suboptimal organs harvested from living donors or cadavers. These organs may engender health complications as age, risk factors, and pathologies of donors fail to meet the standard donor criteria. After examining a wide array of literature on suboptimal kidney transplants, we evidenced two major issues: the lack of standardized terminology and the lack of longterm data on the health outcomes of both suboptimal living donors and recipients. Consequently, surgeons are still unable to provide patients with thorough information to obtain a well-informed consent. Suboptimal kidney transplantation still remains in its experimental stage, thereby raising many ethical and medico-legal concerns. We suggest that one possible solution to overcome some of the ethical shortcomings of suboptimal kidney donations is to provide living donors and recipients honest, accurate, and thorough information about its health risks. To this aim, we advocate adopting a widely standardized terminology that would embrace the whole concept of suboptimal kidney transplantation, increasing the number of future publications on the health outcomes of living donors and recipients, spurring ethical reflection to improve the experience of suboptimal kidney transplantation and reduce the waiting-list for kidney transplantation.

Ethical Issues Surrounding High-Risk Kidney Recipients: Implications for the Living Donor

Evaulating patients for living kidney donor transplantation involving a recipient with significant medical issues can create an ethical debate about whether to proceed with surgery. Donors must be informed of the surgical risk to proceed with donating a kidney and their decision must be a voluntary one. A detailed informed consent should be obtained from high-risk living kidney donor transplant recipients as well as donors and family members after the high perioperative risk potential has been explained to them. In addition, family members need to be informed of and acknowledge that a living kidney donor transplant recipient with pretransplant extrarenal morbidity has a higher risk of a serious adverse outcome event such as graft failure or recipient death. We review 2 cases involving living kidney donor transplant recipients with significant comorbidity and discuss ethical considerations, donor risk, and the need for an extended informed consent.

Pre-existing arteriosclerotic intimal thickening in living-donor kidneys reflects allograft function

BACKGROUND

Donor shortage is a serious problem worldwide and it is now debated whether kidneys from marginal donors are suitable for renal transplantation. Recent studies have shown that the findings of preimplantation kidney biopsy are useful to evaluate vasculopathy in the donated kidney, and may predict transplant outcomes in deceased- donor kidney transplantation. However, few studies have focused on the pathological findings of preimplantation biopsy in living-donor kidney transplantation. Therefore, we investigated whether arteriosclerotic vasculopathy in living-donor kidneys at the time of transplantation predicts the recipient's kidney function (allograft function) later in life.

METHODS

We retrospectively analyzed 75 consecutive adult living-donor kidney transplants performed at Kagawa University Hospital. Renal arteriosclerotic vasculopathy was defined according to the presence of fibrous intimal thickening in the interlobular artery.

RESULTS

Forty-one kidneys exhibited mild arteriosclerotic vasculopathy on preimplantation kidney biopsies. The decreases in estimated glomerular filtration rate after donation were similar in donors with or without renal arteriosclerotic vasculopathy. Pre-existing arteriosclerotic vasculopathy did not affect graft survival rate, patient survival rate or the incidence of complications. Recipients of kidneys with arteriosclerotic vasculopathy had lower allograft function at 1 and 3 years after transplantation than the recipients of arteriosclerosis-free kidneys with or without donor hypertension. In multivariate analysis, fibrous intimal thickening on preimplantation biopsy was predictive of reduced allograft function at 1 year after transplantation.

CONCLUSIONS

The present study demonstrated that mild arteriosclerotic vasculopathy in the donated kidney is an important pathological factor that reflects future impaired function of renal allografts from marginal donors.

Medical follow-up of living kidney donors by 1 year after nephrectomy

BACKGROUND

Concerns have been raised that many kidney donors do not receive adequate medical care after nephrectomy. In 2003, our program developed a policy recommending that donors receive medical follow-up by 12 months postnephrectomy. We hypothesized that medically complex donors would have a higher rate of follow-up than other donors.

METHODS

A retrospective cohort study of 137 live kidney donors from a single center was performed. Donors were considered medically complex if they had hypertension, body mass index of 30 or greater, nephrolithiasis, age 65 years or older, creatinine clearance less than 80 mL/min/1.73 m(2), or had a first-degree relative with diabetes mellitus. Adequate follow-up was defined as one visit with a nephrologist at our center, or blood pressure, serum creatinine, and urinalysis checked elsewhere.

RESULTS

Eighty-three donors (61%) had adequate follow-up, 42 did not, and 12 could not be contacted. At multivariate logistic regression, donors with adequate follow-up were more likely to be medically complex (odds ratio, 2.48; 95% confidence interval 1.18-5.23; P = .02) and older than donors with inadequate follow-up (odds ratio, 1.46 per 10 years of age; 95% confidence interval, 1.01-2.10; P = .04).

CONCLUSION

A substantial minority of donors do not receive recommended care by 1 year after nephrectomy.

Elective surgical patients as living organ donors: a clinical and ethical innovation

We propose a new model for living organ donation that would invite elective laparoscopic cholecystectomy patients to become volunteer, unrelated living kidney donors. Such donors would be surgical patients first and living donors second, in contrast to the current system, which 'creates' a surgical patient by operating on a healthy individual. Elective surgery patients have accepted the risks of anesthesia and surgery for their own surgical needs but would face additional surgical risks when a donor nephrectomy is combined with their cholecystectomy procedure. Because these two procedures have never been performed together, the precise level of additional risk entailed in such a combined approach is unknown and will require further study. However, considering the large number of elective cholecystectomies performed each year in the United States, if as few as 5% of elective cholecystectomy patients agreed to also serve as living kidney donors, the number of living kidney donors would increase substantially. If this proposal is accepted by a minority of patients and surgeons, and proves safe and effective in a protocol study, it could be applied to other elective abdominal surgery procedures and used to obtain other abdominal donor organs (e.g. liver and intestinal segments) for transplantation.

Marginal kidney donor

Renal transplantation is the treatment of choice for a medically eligible patient with end stage renal disease. The number of renal transplants has increased rapidly over the last two decades. However, the demand for organs has increased even more. This disparity between the availability of organs and waitlisted patients for transplants has forced many transplant centers across the world to use marginal kidneys and donors. We performed a Medline search to establish the current status of marginal kidney donors in the world. Transplant programs using marginal deceased renal grafts is well established. The focus is now on efforts to improve their results. Utilization of non-heart-beating donors is still in a plateau phase and comprises a minor percentage of deceased donations. The main concern is primary non-function of the renal graft apart from legal and ethical issues. Transplants with living donors outnumbered cadaveric transplants at many centers in the last decade. There has been an increased use of marginal living kidney donors with some acceptable medical risks. Our primary concern is the safety of the living donor. There is not enough scientific data available to quantify the risks involved for such donation. The definition of marginal living donor is still not clear and there are no uniform recommendations. The decision must be tailored to each donor who in turn should be actively involved at all levels of the decision-making process. In the current circumstances, our responsibility is very crucial in making decisions for either accepting or rejecting a marginal living donor.