Vagus nerve signal has an inhibitory influence on the development of peritoneal metastasis in murine gastric cancer.

The vagus nerve is the only pathway for transmitting parasympathetic signals between the brain and thoracoabdominal organs, thereby exhibiting anti-inflammatory functions through the cholinergic anti-inflammatory pathway. Despite often being resected during lymph node dissection in upper gastrointestinal cancer surgery, the impact of vagotomy on postoperative outcomes in gastric cancer patients remains unclear. Sub-diaphragmatic vagotomy was performed on C57BL/6 mice. Three weeks later, syngeneic murine gastric cancer cell line YTN16P was injected into the peritoneal cavity, and the number of peritoneal metastases (PM) on the mesentery and omentum compared with control mice. The phenotypes of immune cells in peritoneal lavage and omental milky spots one day after tumor inoculation were analyzed using flow cytometry and immunohistochemistry. Intraperitoneal transfer of 3 × 105 YTN16P significantly increased the number of metastatic nodules on the mesentery in the vagotomy group compared to the control group. The omental metastasis grade was also significantly higher in the vagotomy group. Phenotypic analysis of immune cells in peritoneal lavage did not reveal significant differences after vagotomy. However, vagotomized mice exhibited a notable increase in milky spot area, with a higher presence of cytokeratin(+) tumor cells, F4/80(+) macrophages, and CD3(+) T cells. Vagus nerve signaling appears to regulate the immune response dynamics within milky spots against disseminated tumor cells and inhibits the development of PM. Preserving the vagus nerve may offer advantages in advanced gastric cancer surgery to reduce peritoneal recurrence.

Mesocolic hernia after laparoscopic transverse colectomy: A case report.

INTRODUCTION: Internal hernias are rare after laparoscopic colorectal resections. We report a patient with an internal hernia through a defect in the transverse mesocolon following laparoscopic resection. PRESENTATION OF CASE: A 52-year-old male underwent laparoscopic colectomy for transverse colon cancer and had an unremarkable postoperative course. Thirty days postoperatively, he presented to the emergency room with sudden onset abdominal pain and vomiting. Enhanced abdominal computed tomography scan showed strangulated small intestine in the left upper abdomen. An internal hernia through the mesenteric defect created during the recent colon resection was suspected, and emergency laparotomy was performed. One hundred thirty cm of small intestine was found herniated through a mesenteric defect. After repositioning the ischemic-appearing intestine, a 5 cm defect in the transverse mesocolon was found which had not been closed during the previous laparoscopic operation. No intestinal resection was needed, and the mesenteric defect closed with non-absorbable sutures. The post-operative course was unremarkable except for paralytic ileus, which resolved without further intervention. DISCUSSION: The incidence of internal hernia through a mesenteric defect after laparoscopic colorectal resection is quite low. Therefore, routine closure of the mesenteric defect after laparoscopic colorectal resection is not required. However, a left sided defect in the transverse mesocolon might be at higher risk of causing an internal hernia on anatomic grounds. CONCLUSION: We believe that mesenteric defects should be closed after laparoscopic resection of the left side of transverse colon, regardless of their size.