Learning curve of robot-assisted middle pancreatectomy (RMP): experience of the first 100 cases from a high-volume pancreatic center in China

Middle pancreatectomy (MP) is safe and feasible in patients with benign or low-grade malignant tumors located at the neck or proximal body of the pancreas. As a tissue-sparing operation, MP can preserve normal pancreatic function and reduce the risk of postoperative endocrine and exocrine insufficiency. However, the morbidity, especially the postoperative pancreatic fistula (POPF) rate, remains high. A robot-assisted surgical system may provide patients with less trauma; however, there are few reports on robot-assisted middle pancreatectomy (RMP). We describe the experience of RMP at our center to illustrate the learning curve (LC).

From August 2010 to July 2017, 100 patients underwent RMP in the Pancreatic Disease Center of Shanghai Ruijin Hospital affiliated to Shanghai Jiaotong University School of Medicine. Patient characteristics, operative outcomes, and oncological outcomes were collected and analyzed. The CUSUM curve was analyzed according to operative time and estimated blood loss (EBL) and was used to describe the LC and identify the flexion points.

Among the 100 patients who underwent RMP in our hospital, the mean age was 47.5 ± 14.2 years, and 69 patients were female. From the CUSUM curve, we found two flexion points: cases 12 and 44. After 44 cases, the rate of improvement was much faster. We separated the patients into two groups based on the LC (cases 1–44 and cases 45–100). There were significant improvements in operative time (173.1 ± 44.7 min vs. 137.3 ± 30.1 min, p < 0.001) and EBL (103.4 ± 90.0 ml vs. 69.3 ± 53.9 ml, p = 0.021). The overall POPF rate was 32% (32/100), while the incidence rate of biochemical leakage was 14% (14/100). However, there was no significant difference in the risk of POPF or other complications between the two groups. The postoperative length of stay (LOS) was also not different. The 90-day mortality rate was 1%. From our long-term follow-up, pancreatic function was preserved in most patients, with only three cases of endocrine insufficiency and two cases of exocrine insufficiency.

RMP was helpful and a good choice for the selected patients. PF was the main complication and has not been improved until now. There were two flexion points in the LC at cases 12 and 44. More cases are needed to gain more experience. A larger sample size and prospective studies are needed to verify the advantage of RMP.