Laparoscopic modified lymphadenectomy in gastric cancer surgery using systematic mesogastric excision: a novel technique based on a concept.

Radical surgery for gastrointestinal cancer involves en bloc removal of the primary tumor and organ-specific mesenteries. However, the surgical concept and technique for lymphadenectomy during gastric cancer surgery remain unclear. We examined a novel technique for laparoscopic modified lymphadenectomy during gastric cancer surgery involving systematic mesogastric excision (SME) and focused on the topographic anatomy, surgical technique, and specimens. Our surgical technique involved the following: mesenterization by dissociating embryological planes, separating fat tissue containing lymph nodes from the pancreas and its associated vessels by tracing the intramesenteric dissectable layers, and dissecting the lymph node that is dependent on the D1+ criteria. Between October 2011 and September 2016, 227 patients underwent laparoscopic D1+ gastrectomy using SME. Of these, total gastrectomy was performed in 47 cases and distal gastrectomy was performed in 180 cases. The median operative time was 303 min (range, 201-722 min), and estimated blood loss was 50 mL (range, 0-550 mL). The median number of harvested lymph nodes was 54 (range, 18-163). There was no conversion to open surgery. SME was adapted for modified gastrectomy and is considered safe. Modified lymphadenectomy during gastrectomy is determined by the resection margin of the mesogastrium.