Learning curve of totally robotic pancreaticoduodenectomy in early-career surgeons: a dual analysis using CUSUM and moving average.

BACKGROUND

Robotic pancreaticoduodenectomy (RPD) is increasingly performed, but most learning curve studies involved senior surgeons with laparoscopic pancreaticoduodenectomy (LPD) experience. Evidence is lacking for early-career surgeons transitioning directly from open surgery to robotics. This study aimed to evaluate the learning curve of RPD using dual analytic methods and to explore efficiency gains through sub-phase analysis of operative time.

METHODS

We retrospectively analyzed 78 consecutive RPD performed by a single early-career surgeon (May 2023-August 2025). Learning curves were assessed using cumulative sum (CUSUM) and five-case moving average analyses of operative time. Perioperative and postoperative outcomes were compared across phases. In addition, operative time was subdivided into docking, resection, and anastomosis to evaluate phase-specific efficiency gains.

RESULTS

CUSUM identified proficiency at case 23, and moving average showed stabilization at case 41, delineating three phases: initial learning (1-22), proficiency (23-41), and stabilization (42-78). Mean operative time decreased significantly across phases (523.6 → 309.3 min; p < 0.001). Clinically relevant pancreatic fistula declined from 31.8 to 5.4% (p = 0.012). Conversion to open surgery was 3.8%. Sub-phase analysis demonstrated that most reductions were attributable to shorter resection and docking times, while anastomosis time remained stable. Oncologic adequacy was preserved (mean lymph nodes 18.6, R0 resection 97.4%). No 90-day mortality occurred.

CONCLUSION

In this single-surgeon series, operative proficiency appeared after approximately 23 cases and stabilized after 41 cases. Dual analytic methods revealed complementary insights into the learning curve, and sub-phase analysis highlighted that efficiency gains were primarily achieved in resection and docking. RPD may represent a feasible training pathway for early-career surgeons in structured high-volume environments with appropriate mentorship.