Complex Kidneys for Complex Patients: The Risk Associated With Transplantation of Kidneys With Multiple Arteries Into Obese Patients

• We analyze the impact of complex graft vasculature on obese kidney transplant recipients.
• Renal arterial multiplicity is detrimental to graft survival.
• Obese recipients are at higher risk of poor outcomes if receiving grafts of complex vasculature.
• Our analysis aids informed clinical and patient decision-making with regard to organ allocation.

Conflicting evidence surrounds clinical outcomes in obese individuals after transplantation; nonetheless, many are denied the opportunity to receive a transplant. Allografts with complex vascular anatomy are regularly used in both deceased and living donor settings. We established the risk of transplanting kidneys with multiple renal arteries into obese recipients. A retrospective analysis of data from 1095 patients undergoing renal transplantation between January 2004 and July 2013 at a single centre was conducted. Of these, 24.2% were obese (body mass index >30 kg/m2), whereas 25.1% of kidneys transplanted had multiple arteries, thereby making the transplantation of kidneys of complex anatomy into obese recipients a relatively common clinical occurrence. Vessel multiplicity was associated with inferior 1-year graft survival (85.8.% vs 92.1%, P = .004). Obese patients had worse 1-graft survival compared to those of normal BMI (86.8% vs 93.8%, P = .001). The risk of vascular complications and of graft loss within a year after transplantation were greater when grafts with multiple arteries were transplanted into obese recipients as compared to their nonobese counterparts (RR 2.00, CI 95% 1.07–3.65, and RR 1.95, CI 95% 1.02–3.65). Additionally, obese patients faced significantly higher risk of graft loss if receiving a kidney with multiple arteries compared to one of normal anatomy (RR 1.97, 95% CI 1.02–3.72). Thus, obese patients receiving complex anatomy kidneys face poorer outcomes, which should be considered when allocating organs, seeking consent, and arranging for aftercare.