Intestinal obstruction due to internal hernia with dual defects following laparoscopic retroperitoneal tumor resection: a case report.

Introduction and importance: Internal hernias following retroperitoneal surgery are rare but potentially life-threatening. We report a case of intestinal obstruction caused by an internal hernia with dual hernia orifices after laparoscopic retroperitoneal tumor resection, highlighting the unique pathogenesis and the importance of mesenteric defect closure in retroperitoneal surgery. Presentation of case: A 60-year-old female patient underwent laparoscopic transabdominal resection of a retroperitoneal tumor located in the lower pole of the left kidney. On postoperative day 23, the patient presented with vomiting and abdominal pain. Contrast-enhanced computed tomography revealed a closed-loop obstruction extending into the perirenal space, with congested and dilated small bowel within the abdominal cavity, suggesting an internal hernia through multiple orifices. Emergency laparotomy revealed small bowel incarceration in the perirenal space through the descending mesocolon and Gerota's fascia. The herniated bowel adhered to the perirenal space, preventing spontaneous reduction. No intestinal necrosis was observed. Adhesiolysis and bowel reduction were performed, followed by suture closure of the mesenteric defect and omental patching of Gerota's fascia defect. No hernia recurrence was observed 4 months postoperatively. Clinical discussion: Dual hernia orifices involving the mesentery and Gerota's fascia led to bowel entrapment and intestinal obstruction. Adhesion of the leading bowel segment within the perirenal space may have hindered spontaneous reduction, thereby promoting bowel ischemia. Conclusion: In laparoscopic retroperitoneal tumor resection, combined mesenteric and retroperitoneal defects are an important risk factor for intestinal obstruction due to internal hernia.