This retrospective observational study analyses the reasons why potential living kidney donors were declined at the Cantonal Hospital St. Gallen in Switzerland between 2007 and 2021. The goal was to identify the medical/surgical, immunological, and psychosocial factors influencing donor eligibility and trends in donor acceptance over time.
275 donor candidates were evaluated for 161 recipients, 71.6% (197 donors) were declined and 28.4% (78 donors) were accepted. Most candidates were female (61.1%), and acceptance didn’t differ significantly by sex. The average donor age was 54 years, with age-related variations in decline reasons.
The main factors behind donor exclusion were:
Medical & Surgical (32.7%)
– Kidney-related conditions (9.5%), especially low eGFR or complex renal anatomy.
– Diabetes (6.5%), hypertension (5.1%), cardiovascular issues (4.7%), and obesity (2.5%).
Immunological (21.1%)
– Positive crossmatches, donor-specific antibodies with or without blood group incompatibilities.
– Immunological reasons were most common in recipients with prior transplants (70.5%).
Psychosocial (12.7%)
– Mental health issues, withdrawal of consent, family or financial conflicts.
– These were similarly distributed across age groups but slightly more common in younger donors.
Over time, a gradual increase in accepted donor age was observed and accepted donors showed lower eGFR, indicating a shift toward accepting medically more complex cases. The BMI remained relatively stable, although a BMI above a relatively strict but widely used threshold (>35 kg/m²) was viewed as contraindication.
Regarding the policy and evaluation process, the following statements can be made. The donor evaluation followed Swiss national guidelines, prioritizing donor safety while balancing ethical concerns. Assessments included medical, surgical, psychosocial, and immunological reviews. Decisions were made holistically.
The study calls for early psychological screening in the evaluation process. Switzerland’s Kidney Paired Donation (KPD) program has been slow to scale, and international collaboration is suggested to potentially expand donor pools. The findings of this study align with KDIGO 2017 guidelines, emphasizing the need for tailored risk assessments, especially for complex donors and offer valuable insights into living donor management within Central Europe, encouraging more evidence-based and transparent selection criteria.
Interview with Dr. med. Ritter Alexander (St. Gallen)
What inspired you to conduct this study?
Living kidney donation is vital in addressing organ shortages, yet most research focuses on accepted donors. However, many donor candidates are declined, and little is known about their characteristics. Switzerland was the first country to establish a prospective living donor registry (SOL-DHR), which not only provides donor follow-up but has also become an important tool for studying donor outcomes. Ultimately, studies like ours can complement donor registry derived data and may help refine evaluation practices and, importantly, identify opportunities to safely expand the donor pool.
Were there any unexpected findings?
Although not entirely surprising, we observed notable differences from Anglo-American studies: diabetes and obesity were far less common reasons for decline, whereas immunological and psychosocial factors were more prominent. Over time, more medically complex donors - such as older candidates with lower kidney function - were accepted, reflecting international practice but raising concerns about long-term safety.
What is the direct impact on the surgeon’s work?
The direct impact of the study on surgical work is probably limited, but it shows that the donor population is becoming increasingly medically complex, which requires careful surgical planning and risk stratification often in a multidisciplinary setting. New retrieval methods, such as the Da Vinci robot, are being used increasingly and could be advantageous in this evolving donor population
What is your learning point from this project?
We need to continue critically examining the boundaries between declined and accepted donor pools in outcome studies using registry data, in order to eventually expand the donor pool safely. Novel desensitization protocols and international collaborations for the kidney paired donation program may help to overcome immunological barriers, particularly in a relatively small country like Switzerland.
Are there any subsequent projects planned?
Not exactly, but long-term outcome studies of medically complex donors remain crucial to ensure donor safety as well as studies on interventions - such as lifestyle modification, novel therapies or desensitization protocols - that could help convert currently ineligible candidates into suitable donors.
