The required experience of open pancreaticoduodenectomy before becoming a specialist in hepatobiliary and pancreatic surgeons: a multicenter, cohort study of 334 open pancreaticoduodenectomies.

Background: Open pancreaticoduodenectomy (OPD) is an essential surgical procedure for expert hepato-biliary-pancreatic (HBP) surgeons. However, there is no standard for how many surgeries must be performed by a surgeon in training before they are considered to have enough experience to ensure surgical safety.

Methods: Cumulative Sum (CUSUM) analysis was performed using the surgical data of OPDs performed during the training period of board-certified expert surgeons of the Japanese Society of Hepato-Biliary-Pancreatic Surgery.

Results: Fourteen HBP surgeons participated in this study and performed 334 OPDs during their training period. The median (interquartile range) values for operative time, blood loss, and length of hospital stay were 455 (397-519) minutes, 450 (234--716) ml, and 28 (21-38) days, respectively. CUSUM analysis showed inflection points at 20 surgeries performed for operative time. After 20 procedures, operative time was significantly shorter (461 min vs. 425 min, p = 0.021) and blood loss was significantly lower (470 ml vs. 340 ml, p = 0.038). No significant differences between within 20 and after 21 procedures were found in the complication rate (53% vs. 48%, p = 0.424) and rate of in-hospital deaths (1.5% vs.1.4%. p = 0.945). Up to 20 surgeries, PDAC and another malignant tumor had longer operative time than benign/low malignant diseases (486 min vs. 472 min vs. 429 min, p < 0.001), and higher blood loss (500 ml vs. 502 ml vs. 355 ml, p < 0.001). Mortality rate was higher at PDAC cases (5% vs. 0% vs. 0%, p = 0.01). After the 21 procedures, these outcomes were improved and no differences in by primary disease were observed. Multivariable analysis showed that within 20 surgeries were independent risk factors of longer operative time (HR2.6, p = 0.013) and higher blood loss (HR2.0, p = 0.049).

Conclusions: To stabilize the surgical outcome of OPD for malignant disease, at least 20 surgeries should be performed at a certified institution during surgeon training.

Trial registration: Clinical trial number: Not applicable.