Diagnosis and treatment of incarcerated inguinal hernia with "complete reduction": a case report

Reduction en masse (REM) of an incarcerated inguinal hernia is a rare but serious diagnostic pitfall in which apparently successful reduction masks a persistent closed-loop obstruction within the preperitoneal space. Rather than returning to the peritoneal cavity, the hernia sac and its contents are displaced together as a single unit, so the constricting ring continues to compromise the trapped bowel. The result is an occult internal hernia that carries a high risk of bowel strangulation when diagnosis is delayed, yet the deceptively benign external examination frequently leads clinicians to attribute persistent symptoms to other causes.

A 70-year-old man presented with small-bowel obstruction 48 hours after forcefully self-reducing a right inguinal hernia. The external bulge had resolved, but obstructive symptoms persisted and progressed. Contrast-enhanced computed tomography (CT) revealed a pathognomonic "preperitoneal hernia-sac sign": a rounded, obstructed jejunal loop adjacent to the inferior epigastric vessels. Diagnostic laparoscopy confirmed REM, with 10 cm of viable but oedematous small bowel trapped within a direct hernia defect. The constriction was released, a serosal tear was oversewn, and the internal ring was closed. Following conservative management of a postoperative pelvic haematoma, a second-stage open tissue repair was performed one week later. The patient recovered well and remained recurrence free at six-month follow-up.

REM should be suspected in any patient with persistent obstructive symptoms after apparent hernia reduction, particularly when there is a history of forceful self-reduction. High-resolution contrast-enhanced CT demonstrating the "preperitoneal hernia-sac sign" is crucial for early diagnosis. Prompt laparoscopic exploration is both diagnostic and therapeutic, enabling assessment of bowel viability, release of the incarceration, and definitive repair while reducing postoperative morbidity. A staged repair strategy is safe and effective in contaminated or oedematous surgical fields. Greater clinician awareness and the systematic consideration of REM in emergency settings can prevent diagnostic delay and its serious consequences.