Traumatic Diaphragmatic Hernia: An Unusual Complication of Colonoscopy

Abstract

Purpose: We report a case of diaphragmatic herniation during a colonoscopy, via an occult diaphragmatic weakness from the patient's prior trauma. A 68 y/o male underwent screening colonoscopy with sigmoid polypectomy. The procedure was unremarkable and well tolerated. Five days later, he presented to the hospital with left upper and bilateral lower abdominal crampy pain, associated with nausea, vomiting, loss of appetite, and abdominal distension with no BM for last 5 days. One year prior, he had been involved in a fall, with blunt trauma to his left lateral thorax resulting in multiple rib fractures with flail segment and hemothorax, which was treated with closed thoracostomy drainage. Chest X-ray showed focal elevation of the left diaphragm after treatment for hemothorax. However, the diaphragm appeared intact on CT. Review of systems was remarkable for mild intermittent left upper abdominal pain with early satiety and nausea for several months with worsening of his symptoms for last 5 days since colonoscopy. Physical examination revealed: mild abdominal distension with tympany, tenderness in left upper quadrant and hypoactive bowel sounds. Abdominal-X-ray showed protrusion of the large bowel into the left thoracic cavity along with elevation of the left diaphragm. There was no free air in the peritoneal cavity. Abdominal CT confirmed the herniation of the splenic flexure through a defect in the midportion of the left hemidiaphragm. The proximal colon and terminal ileum were dilated with air-fluid levels consistent with bowel obstruction. Subsequently, the patient underwent exploratory laparotomy which showed left diaphragmatic hernia and incarcerated colon and omentum with colonic obstruction. A reduction repair of the hernia was performed and patient was discharged with an uncomplicated post-op course. Diaphragmatic rupture develops in about 5% of cases of blunt abdominal trauma, and is more frequent on the left side. It may be asymptomatic and diagnosis may be delayed for many years. Because the intraabdominal pressure is higher than intrathoracic pressure, progressive herniation of abdominal contents may occur through the defect. Undiagnosed traumatic diaphragmatic hernia encountered during colonoscopy has been rarely reported. Colon perforation leading to tension pneumothorax has also been described. However, in our case, the patient had no evidence of a diaphragmatic defect after trauma or treatment for left hemothorax. Continuous insufflation of air during the colonoscopy seems to have induced an increase in intra-abdominal pressure, which resulted in conversion of an occult focal diaphragmatic weakness into a true defect leading to sudden herniation of the colon into the thoracic cavity.