Implementing a structured CT reporting tool for patients with Roux-en-Y gastric bypass (RYGB) surgery history could prevent missing internal hernia as the potential cause of abdominal pain.
In hospital emergency departments, RYGB patients may present with abdominal pain following the common bariatric procedure and be mistakenly diagnosed with reflux disease, gastritis, gallstone disease, or marginal ulcer, according to lead author Joseph Sanchez, MD, and colleagues from the Northwestern University Feinberg School of Medicine in Chicago. Findings from their quality improvement intervention were published on August 18 in Surgical Endoscopy.
“Although the sensitivity of diagnosing a small bowel obstruction on CT can approach 94% to 100%, internal hernias following RYGB can be difficult to detect when they are not associated with a small bowel obstruction, because of the patients’ altered surgical anatomy and subtlety of some of the imaging signs,” the group explained.
They adopted use of a structured CT reporting tool developed in May 2023 and assessed its effectiveness toward improving internal hernia detection after RYGB. According to the team, the tool incorporates certain signs of internal hernia directly into CT reads and impressions.
Prior to using the tool, radiology residents, abdominal radiology fellows, emergency radiology and abdominal radiology attendings received education on detection of internal hernias via CT scanning. Using the tool was optional at the discretion of the individual radiologist, the group noted.
For their study, researchers compared internal hernias detected and missed in a preintervention group (n = 139 CT scans) to those of a postintervention group (n = 193 CT scans), in which the tool was applied to 49.7% of the scans.
They found that for the postintervention group, eight (3.7%) radiographic diagnoses of internal hernia were made, six of which underwent operative reduction. Two diagnoses of internal hernia were missed on CT imaging (1.1%).
Working without the tool, five radiographic diagnoses of internal hernia were made, four of which underwent operative reduction. Six internal hernias (3.7%) were missed by CT. All six required surgical reduction, with one experiencing entire small bowel necrosis resulting in resection and small bowel transplantation, according to the group.
Sensitivity for internal hernia detection in the pre- and postintervention groups was 40% versus 75% (p = 0.14), and the specificity was 99.2% versus 98.9%, respectively (p = 0.79), they reported.
“An additional finding of our study was that individual reported components of the structured CT reporting tool had variable sensitivities and specificities,” Sanchez and colleagues wrote. At the very least, CT reports should incorporate mesenteric swirl pattern, mesenteric edema, or an abnormal SMV, and bowel loops located posterior to the Roux loop mesentery to ensure detection of internal hernia, they pointed out.
Radiologists have come to prefer some structured CT reporting tools over free-text reports, and this study suggests that a structured CT reporting tool may aid in the evaluation of internal hernias following RYGB, according to the group.
Importantly, “surgeons still hold an important role in making a clinical diagnosis of internal hernia as not all CT scans will accurately diagnose an internal hernia,” they added.
Read the complete paper here.