Successful laparoscopic repair for reduction en masse of infantile inguinal hernia: a case report of this rare condition

BACKGROUND: Reduction en masse (REM) is a rare condition following manual inguinal hernia (IH) reduction in which a hernia sac is reduced back into the preperitoneal space with a loop of the bowel incarcerated at the neck of the sac. It resembles successful manual reduction and may thus be overlooked easily. We herein report an infantile case of REM of an IH that was successfully treated laparoscopically. CASE PRESENTATION: A 10-month-old boy with a surgical history of bilateral open IH repair at 4 months old presented with a bulge in his left groin and vomiting. A left incarcerated recurrent IH was suspected, and manual reduction was performed. The hernia was apparently reduced successfully, but abdominal distention and vomiting persisted. He was admitted for further observation due to the symptoms. On day 2 after admission, abdominal X-ray showed extensive small bowel obstruction (SBO). Enhanced computed tomography (CT) revealed protrusion of the small bowel with a closed-loop in the left groin. A closed-loop SBO due to postoperative adhesion or an internal hernia was suspected. To assess the etiology of SBO, emergent laparoscopic exploration with hernia repair was planned. Laparoscopy revealed REM of the left incarcerated IH with a thickened peritoneum at the neck of the sac. Laparoscopic reduction was performed, and the incarcerated small bowel showed no signs of ischemia. The hernia sac was not associated with the previously ligated processes vaginalis, which had been closed by a previous Potts’ procedure. It was located at the inside of the processes vaginalis. The sac was successfully closed by laparoscopic percutaneous extraperitoneal closure procedures, and iliopubic tract repair was also performed via the previous inguinal incision. The postoperative course was uneventful. CONCLUSION: Pediatric IH is due to the patent processes vaginalis, and REM is extremely rare. Laparoscopic surgery for REM is a relatively common and useful approach for the diagnosis and treatment of adults. In our infantile case, the laparoscopic approach was similarly effective for both investigating the cause of SBO and performing high ligation of the sac for this rare condition with IH. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40792-022-01535-1.