D2 Lymph Node Dissections during Reduced-port Robotic Distal Subtotal Gastrectomy and Conventional Laparoscopic Surgery Performed by a Single Surgeon in a High-volume Center: a Propensity Score-matched Analysis

Purpose: Various studies have indicated that reduced-port robotic gastrectomies are safe and feasible for treating patients with early gastric cancer. However, there have not been any comparative studies conducted that have evaluated patients with clinically advanced gastric cancer. Therefore, we aimed to compare the perioperative outcomes of D2 lymph node dissections during reduced-port robotic distal subtotal gastrectomies (RRDGs) and conventional 5-port laparoscopic distal subtotal gastrectomies (CLDGs). Materials and Methods: We retrospectively evaluated 118 patients with clinically advanced gastric cancer who underwent minimally invasive distal subtotal gastrectomies with D2 lymph node dissections between February 2016 and November 2019. To evaluate the patient data, we performed a 1:1 propensity score matching (PSM) according to age, sex, body mass index, American Society of Anesthesiologists physical status classification score, and clinical T status. The short-term surgical outcomes were also compared between the two groups. Results: The PSM identified 40 pairs of patients who underwent RRDG or CLDG. The RRDG group experienced a significantly longer operation time than the CLDG group (P<0.001), although the RRDG group had significantly less estimated blood loss (P=0.034). The number of retrieved extraperigastric lymph nodes in the RRDG group was significantly higher than that of the CLDG group (P=0.008). The rate of postoperative complications was not significantly different between the two groups (P=0.115). Conclusions: D2 lymph node dissections can be safely performed during RRDGs and the perioperative outcomes appear to be comparable to those of conventional laparoscopic surgeries. Further studies are needed to compare long-term survival outcomes.