We evaluated perioperative and long-term outcomes of minimally invasive surgery (MIS) and established indications of MIS in solid pseudopapillary tumor (SPT) in pediatric patients.

From October 1992 to April 2018, 66 patients (age, <18 years) diagnosed with SPT underwent either open pancreatectomy (OP) or MIS. Variables including postoperative complications and recurrence rates were retrospectively analyzed.

Thirty-five patients underwent open surgery and 31 underwent laparoscopic/robotic surgery. Mean tumor size in MIS was significantly smaller than that in OP (4.3±1.8 cm vs. 7.6±3.5 cm, p=0.005). There were 4 cases of open conversion from laparoscopic surgery because of vessel encasements (n=2), bleeding (n=1), and pancreatic ductal injury (n=1). Solitary pseudopapillary carcinoma was diagnosed in 6 patients. Recurrence was observed in 3 and 1 patients who underwent OP and MIS, respectively (p=0.634). Tumor size, mass size/abdominal diameter (MS/AD) ratio, and degree of the portal or superior mesenteric vein involvement were the most important indications for MIS.

MIS is being widely used in pediatric surgeries with increased expertise and safety, especially in pancreatic diseases. Careful patient selection for MIS in regards with parameters such as MS/AD ratio and vessel abutment might be a feasible choice.

Purpose
Thoracoscopic repair of congenital diaphragmatic hernia (CDH) is technically challenging and requires various surgical strategies. However, studies investigating the learning curve of thoracoscopic repair of CDH are rare. The
objective
of this study was to determine whether there is a learning curve of thoracoscopic repair of CDH and analyze its pattern by cumulative sum (CUSUM) analysis.
Methods
From 2008, when the first case was performed, to 2020, children diagnosed with Bochdalek-type CDH who underwent thoracoscopic repair were included. Learning curves of 2 operators were analyzed individually using the CUSUM method which is the running total of differences between operation time of each case and the mean operation time. We divided the CUSUM curve into three phases based on its slope and performed interphase analysis of patients’ baseline characteristics and surgical outcomes.
Results
A total of 111 children (operator A, n=88; operator B, n=23) underwent thoracoscopic repair of CDH during the study period. CUSUM curve of operator A showed an ascending curve from the first case to the 33rd case, then a plateau between the 34th case and the 55th case, and a descending form from the 56th case. In interphase comparisons of surgical outcome of operator A, recurrence rate and rate of complication did not show statistically significant differences. The learning curve of operator B showed a flat overall appearance and plateaued after the 14th case.
Conclusion
Surgical experience based on 33 cases was needed to reach the learning curve to perform thoracoscopic repair of CDH. For a new surgeon experienced with assisting a skilled operator, a relatively high proficiency was obtained from the start with a shorter learning curve. Interphase analysis of surgical outcome suggests that thoracoscopic repair of CDH can be performed without compromising patients’ safety even before reaching the learning curve.