Optimizing the diagnostic strategy for accurate detection of internal herniation following Roux-en-Y gastric bypass: a diagnostic accuracy study.

BACKGROUND

Internal herniation is a serious complication after Roux-en-Y gastric bypass (RYGB). Diagnosis is challenging due to nonspecific clinical findings, heterogeneous computed tomography (CT)-based predictive models, and lack of consensus on the optimal diagnostic strategy. Although diagnostic laparoscopic surgery (DLS) is considered the reference standard, it frequently results in negative explorations.

OBJECTIVES

To identify predictive clinical parameters and CT signs for internal herniation in post-RYGB patients presenting with abdominal pain, and to evaluate the clinical decision-making process leading to DLS.

SETTING

Emergency department of a high-volume nonacademic teaching hospital with a dedicated bariatric center in the Netherlands.

METHODS

This prospective diagnostic accuracy study included all adults presenting with acute abdominal pain more than 30 days post-RYGB between March 2023 and June 2024. Standardized clinical, laboratory, and CT assessments were performed. A bariatric surgeon assigned a clinical suspicion score (CSS) and a dedicated radiologist a radiological suspicion score (RSS). Patient management followed a predefined protocol. Predictors were analyzed using Least Absolute Shrinkage and Selection Operator regression.

RESULTS

In total, 125 patients were included. DLS was performed in 84 patients (67%), confirming internal herniation in 30 (36%). CSS was not associated with internal herniation, whereas a higher RSS was strongly associated with its presence (P < .001). Venous congestion, swirl sign, and mushroom sign were identified as independent predictors.

CONCLUSION

Clinical assessment alone has limited reliability in guiding decision-making regarding DLS in post-RYGB patients with abdominal pain. Structured CT assessment by a dedicated abdominal radiologist is the most accurate diagnostic tool and should be performed in all such patients.