Diagnostic nomogram for closed-loop small bowel obstruction requiring emergency surgery

Conversion to open surgery in laparoscopic approach of adhesive small bowel obstruction: Predictive factors and its impact on short-term outcomes

BACKGROUND

Small bowel obstruction is a common surgical emergency. Laparoscopy has been increasingly used for the treatment of adhesive small bowel obstruction (ASBO), but its indications remain unclear. In this study, we aimed to identify the risk factors for conversion to open surgery after laparoscopic ASBO treatment and evaluate the impact of conversion on short-term outcomes.

METHODS

All patients diagnosed with ASBO who initially underwent laparoscopic approach after the failure of conservative treatment between December 2020 and May 2024 were reviewed. Patients were categorized into two groups based on the surgical approach: the totally laparoscopic group (group 1) and the conversion to open surgery group (group 2). The demographic, clinical, and radiological features were compared, and risk factors were identified via univariate and multivariate analyses. The intraoperative findings and postoperative outcomes were evaluated.

RESULTS

A total of 102 patients (43 in group 1 and 59 in group 2) were included. The time between home and admission (P ​= ​0.014) and the abdominal wall ratio (P ​< ​0.001) were significantly higher in group 2 than in group 1, whereas the number of prior abdominal surgeries (P ​= ​0.010) and the rate of beak signs were significantly lower in group 2 than in group 1. The operative time (P ​< ​0.001), blood lost (P ​< ​0.001), medical expenses (P ​< ​0.001), total hospital length of stay (P ​< ​0.001), and postoperative hospital length of stay (P ​< ​0.001) were significantly higher in group 2 than in group 1. Multivariate analysis revealed that a large abdominal wall ratio (odds ratio [OR]: 4538.7; 95 ​% confidence interval [CI]: 8.5-2426334.8; P ​= ​0.009) was a risk factor for conversion, whereas the presence of beak signs (OR: 0.186; 95 ​% CI: 0.05-0.64, P ​= ​0.008) was a significant protective factor.

CONCLUSIONS

A large abdominal wall ratio is an independent risk factor for conversion, whereas the presence of beak signs is a protective factor. The conversion from laparoscopic surgery to open surgery is safe with proper management of conversion indications.

A prediction model to differentiate transient ischemia from irreversible transmural necrosis in closed-loop small bowel obstruction

Introduction

The study aims to develop a prediction model to differentiate transient ischemia from irreversible transmural necrosis in closed-loop small bowel obstruction (CL-SBO).

Methods

A total of 180 participants with CL-SBO between January 2010 and December 2019, of which 122 had complete radiologic data, were included to investigate the significant clinical and imaging characteristics for differentiating patients with necrosis from transient ischemia. A logistic regression model was developed and validated.

Results

In a multivariate analysis, the American Society of Anesthesiologists physical status classification system >2 is the independent predictor for transmural necrosis. Another multivariate analysis, including clinical and imaging factors, revealed that the imaging sign of mesenteric vessel interruption was an independent risk factor for necrosis. The diagnostic model developed using these two factors has excellent performance among the validation sets, with an area under the curve of 0.89.

Conclusion

The diagnostic model and innovative imaging signs have substantial potential in solving this complex clinical problem.

Increased Attenuation of Intestinal Contents at CT Indicates Bowel Necrosis in Closed-Loop Small Bowel Obstruction

Background Preoperative recognition of irreversible bowel necrosis is important, as it provides valuable guidance for surgical strategy selection but also may inform perioperative risk assessment and communication. Few studies have focused on the association between CT signs and bowel necrosis. Purpose To assess the diagnostic accuracy of CT signs to predict bowel necrosis in patients with closed-loop small bowel obstruction (CL-SBO). Materials and Methods This retrospective single-center study included patients who were surgically confirmed to have CL-SBO caused by adhesion or internal hernia between January 2016 and May 2022. Necrosis was determined based on surgical exploration and postoperative pathologic examination. Two radiologists independently reviewed CT signs by both subjective visual assessment and objective measurement. Disagreements were resolved in consensus with a third gastrointestinal radiologist. Univariable and multivariable analyses were used to assess the association between CT signs and bowel necrosis, and Cohen κ was used to assess interobserver agreement. Sensitivity and specificity were calculated for each CT sign. Results This study included 145 patients: 61 (42.1%) in the necrotic group (median age, 62 years [IQR, 51-71.5 years]; 37 [60.7%] women) and 84 (57.9%) in the nonnecrotic group (median age, 61.5 years [IQR, 51-68.8 years]; 51 [60.7%] women). Univariable analysis and multivariable analysis showed that increased attenuation of intestinal contents and increased attenuation of intestinal wall were independent predictors for bowel necrosis (odds ratio = 45.3 and 15.1; P = .001 and P < .001, respectively). Increased attenuation of intestinal contents and increased attenuation of intestinal wall had similar sensitivity (64% and 67%, respectively) and specificity (99% and 92%, respectively) for predicting bowel necrosis. However, interobserver agreement was better for assessing the contents than the wall (κ = 0.84 and 0.59, respectively). Conclusion Increased attenuation of intestinal contents was a highly specific CT sign with good reproducibility to predict bowel necrosis in CL-SBO. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Taourel and Zins in this issue.