Sigmoid volvulus: identifying patients requiring emergency surgery with the dark torsion knot sign

Objectives: To determine which clinical or CT imaging factors can help accurately identify complicated sigmoid volvulus (SV), defined as irreversible bowel ischaemia or necrosis requiring emergent surgery in patients with SV. Methods: We performed a retrospective study of 51 patients admitted consecutively to the emergency department for SV. All patients attempted endoscopic detorsion as the first treatment. Clinical and contrast-enhanced CT factors were analysed. A newly described dark torsion knot sign (sudden loss of mucosal enhancement in the volvulus torsion knot) was included as a CT factor. Patients were diagnosed with complicated versus simple SV based on either surgery or follow-up endoscopic findings. Univariate and multivariate analyses were used to identify predictors of complicated SV. Results: Of 51 study patients, 9 patients (17.6%) had complicated SV. Univariate analysis revealed that three clinical factors (sepsis, elevated C-reactive protein, and elevated lactic acid levels) and four CT factors (reduced bowel wall enhancement, increased bowel wall thickness, dark torsion knot sign, and diffuse omental infiltration) were significantly associated with complicated SV. Multivariate analysis identified only dark torsion knot sign (odds ratio = 104.40; p = 0.002) and sepsis (odds ratio = 16.85; p = 0.043) as independent predictive factors of complicated SV. Conclusion: A newly defined CT imaging factor of dark torsion knot sign and a clinical factor of sepsis can predict complicated SV necessitating emergent surgery instead of colonoscopic detorsion as a primary treatment of choice. Key Points: • A newly defined CT imaging factor of dark torsion knot sign and a clinical factor of sepsis can be helpful for predicting complicated SV necessitating emergent surgery instead of endoscopic detorsion.