Robotic Gastrectomy Lowers Blood Loss, Conversions in Japan

Key Takeaways

• In Japan, patients undergoing minimally invasive distal or total gastrectomy for gastric cancer had shorter postoperative hospital stays and fewer conversions to open surgery with robotic surgery than with laparoscopy.
• Robotic distal and total gastrectomy each required more operating time than the corresponding laparoscopic procedures.
• Robotic surgery was associated with lower intraoperative blood loss across both distal and total gastrectomy comparisons.
• Robotic distal gastrectomy was associated with fewer serious postoperative complications and intra-abdominal infections, but robotic total gastrectomy did not significantly improve the primary major-complication outcome versus laparoscopy.

Laparoscopic gastrectomy is an established minimally invasive option for gastric cancer, but the operation remains technically demanding in a confined field where rigid instruments can limit dexterity and magnify tremor. Robotic gastrectomy was adopted to improve precision, dexterity, and visualization during complex dissection and reconstruction. In Japan, national insurance coverage and broader access and training expansion made it timely for investigators to examine whether wider routine use of robotic gastrectomy was associated with different perioperative outcomes than laparoscopy.

Shibasaki and colleagues’ Gastric Cancer registry analysis of robotic versus laparoscopic gastrectomy used Japan’s National Clinical Database for a retrospective cohort comparison of minimally invasive distal gastrectomy (DG) and total gastrectomy (TG) performed from January 2023 through December 2024. Propensity score matching yielded 9,743 robotic-laparoscopic DG pairs and 1,617 robotic-laparoscopic TG pairs, reflecting contemporary routine practice in Japan.

In matched comparisons, robotic gastrectomy (RG) took approximately 50 minutes longer than laparoscopic gastrectomy (LG) for DG and nearly 70 minutes longer for TG, while blood loss was 33–40% lower across the distal and total gastrectomy comparisons. The perioperative tradeoff was longer procedures with less intraoperative blood loss.

Robotic surgery was also associated with a 50–65% lower likelihood of conversion to open surgery and with shorter postoperative hospital stays in both procedure groups. In DG, RG was associated with fewer serious postoperative complications and fewer intra-abdominal infections, whereas in TG the primary major-complication outcome did not improve significantly versus laparoscopy.

Because this was a retrospective, propensity-matched registry comparison, the findings do not establish that the surgical platform itself caused the observed differences. The investigators indicated that the absolute differences were small, and the benefits were not uniform across procedures because the major-complication signal was clearer in DG than in TG. They also suggested that better contemporary robotic outcomes than in earlier nationwide experience may reflect advances in robotic technology, greater experience, and expanded training within the Japanese practice setting.

The authors reported that contemporary robotic gastrectomy in Japan was associated with several perioperative advantages over laparoscopic surgery despite longer operating times, with the complication advantage more evident for distal than for total gastrectomy.

Clinician Questions

Which gastric cancer operations does the robotic versus laparoscopic comparison actually cover?

The comparison covered patients in Japan undergoing minimally invasive distal gastrectomy and total gastrectomy for gastric cancer after propensity score matching of robotic and laparoscopic cases in the National Clinical Database. The findings therefore apply to contemporary Japanese minimally invasive DG and TG practice rather than to open gastrectomy or to gastric cancer surgery in every setting.

Why was the complication advantage clearer for robotic distal gastrectomy than for robotic total gastrectomy?

Robotic distal gastrectomy was associated with fewer serious postoperative complications and fewer intra-abdominal infections, whereas robotic total gastrectomy did not significantly improve the primary major-complication outcome versus laparoscopy. The investigators attributed that difference to total gastrectomy remaining more technically demanding and being performed less often, which may limit opportunities to build robotic experience.

Does this analysis say anything about long-term cancer outcomes after robotic gastrectomy?

The available summary is limited to perioperative and short-term postoperative outcomes such as operating time, blood loss, conversion to open surgery, complications, and postoperative hospital stay. Long-term oncologic outcomes are not provided in the available summary, so no conclusion about cancer control or survival can be drawn from this analysis.