A 70-year-old male presents to the Emergency Room with abdominal pain and distention. The patient has a history stage IV non-small cell lung cancer, chronic obstructive pulmonary disease, hypertension, severe dementia and recent deep venous thrombosis. He presents secondary to 2 days of poor appetite, diffuse abdominal pain, abdominal distention, and increasing dyspnea. He reports no bowel movements in last 2 days.
The decision was made to proceed with a CT of the abdomen and pelvis with intravenous and oral contrast. The following study was obtained.
Whats is the most likely diagnosis?
Diagnosis: High-grade small bowel obstruction due to internal hernia with small bowel pneumatosis and small volume pneumoperitoneum.
In cases with bowel obstruction, the radiologist should aim to identify the cause of the obstruction as early surgical reversal may be curative for the patient. One of the uncommon causes of small bowel obstruction includes internal hernias. This is a difficult diagnosis to make, and a few signs are may be useful to help identify it. Firstly, it is important to look at the overall distribution of the bowel loops. In this case, the distended bowel loops are abnormal in position, as they are within the pelvis as well as positioned anterior to the large bowel.
In this case, the duodenojejunal junction and ligament of Treitz are seen to the right of midline and are positioned inferiorly and posteriorly deep pelvis along the peritoneal reflection. In this case, the low position of the bowel loops may be due to a defect in the sigmoid mesocolon which would make the rare diagnosis of a sigmoid mesocolon hernia.
Most importantly are the ancillary features which make this case a surgical emergency. Firstly, pneumatosis intestinalis is seen within the small bowel wall:
Using the lung window, we are also able to notice subtle pneumoperitoneum:
In cases with suspected bowel ischemia, it is important to additionally look for gas within the portal venous system, which in this case was not present.
Due to multiple comorbidities, and upon further consultation with family and the patient, the decision was made not to operate and undergo conservative management.