Introduction: Kidney transplantation is the preferred treatment for patients with end-stage renal disease. Although the standard of care for kidney transplantation has been the open approach, since the introduction of the robot assisted kidney transplantation (RAKT) in 2009, a number of centers have applied this technique as an alternative to open kidney transplantation (OKT). Early studies have demonstrated the feasibility and safety of RAKT, with graft functions comparable to OKT. The objective of the study is to comprehensively analyze our early experiences, and detail our surgical technique and evaluate the learning curve for RAKT. Postoperative outcomes were assessed to evaluate graft function and overall safety of RAKT.
Methods: We retrospectively reviewed 782 patients who underwent living donor kidney transplantation at our center between January 2018 and January 2024. Patient demographics were collected, and propensity score matching was performed to account for potential confounding factors. The matched cohort was evaluated for intraoperative and postoperative variables. Shewhart control charts and cumulative sum (CUSUM) analysis of ischemic and anastomosis times were used to evaluate technical outcomes and learning curve of RAKT. Postoperative variables were compared, and RAKT and OKT patients were evaluated for overall graft function and safety. Three RAKT risk groupings (moderate, high, very high) were identified based on rewarming times.
Results: Propensity score matching resulted in 50 RAKT and 150 OKT patients, with no significant difference between both groups across all variables. Compared to OKT, RAKT was associated with longer operation time (292.5 min vs 230.0 min; p <0.001), rewarming time (74.0 min vs 36.0 min; p <0.001), nonanastomotic time during rewarming time (27.0 min vs 5.0 min; p <0.001), and venous (24.0 min vs 15.0 min; p <0.001) and arterial (20.5 min vs 15.5 min; p <0.001) anastomosis times. Overall, postoperative eGFR trends showed comparable graft function between RAKT recipients and OKT recipients (p = 0.315); additionally, postoperative eGFR values did show mild improvement in the moderate risk group, but were still statistically comparable to high (p = 0.238) and very high (p = 0.694) risk groups. CUSUM analysis indicated that the learning curve of RAKT rewarming time requires approximately 15 cases.
Conclusion: Robot assisted kidney transplantation is associated with longer anastomosis and ischemic times. However, even during the early experience of RAKT, no significant differences were observed in graft function or postoperative complications compared to open kidney transplantation. RAKT is a complex procedure that requires at least 15 cases to overcome the learning curve. In our experience, given a relatively short learning curve associated with anastomoses, reducing nonanastomotic time during rewarming time appears to be critical for improving overall rewarming time.