Safety in Robotic Kidney Transplant for All-Comers: Does Body Mass Index Need to be Considered?

BACKGROUND

Obesity remains a common barrier to kidney transplantation, with many centers enforcing strict body mass index (BMI) cutoffs due to concerns regarding surgical complexity and postoperative complications. Robotic kidney transplantation (RKT) has emerged as a minimally invasive alternative that may mitigate obesity-associated surgical risks. However, outcomes across granular BMI subgroups, particularly among patients with morbid obesity (BMI ≥40 kg/m2), remain incompletely characterized.

METHODS

We performed a retrospective cohort study of adult patients undergoing RKT at a single academic transplant center between November 2021 and September 2025. Patients were stratified by BMI into two primary cohorts (BMI <30 vs ≥30 kg/m2) with a secondary subgroup analysis comparing those with BMI 30-40 vs ≥40 kg/m2. Demographic characteristics, intraoperative metrics, and 30-day postoperative outcomes were compared.

RESULTS

A total of 104 patients underwent RKT, with 26 patients with BMI<30 kg/m2, 53 with BMI between 30 and 40 kg/m2, and 25 with BMI ≥40 kg/m2. No significant differences were observed between BMI <30 and ≥30 cohorts in operative time, ischemia times, estimated blood loss, length of stay, delayed graft function, or 30-day readmission. Patients with BMI <30 had a higher rate of 30-day all-cause reoperation (15% vs 3%, p=0.03). In subgroup analysis, patients with BMI ≥40 demonstrated comparable intraoperative parameters and postoperative complication rates to those with BMI 30-40, with no significant differences in graft or patient survival.

CONCLUSIONS

Robotic kidney transplantation is associated with comparable perioperative outcomes across BMI categories, including among patients with morbid obesity. These findings challenge rigid BMI-based exclusion criteria and support a more individualized approach to transplant candidacy in the era of robotic surgery.