When is the right time to take an emergency surgery decision in Mechanical Intestinal Obstruction?

Development and validation of a nomogram model to predict the risk of strangulated intestinal obstruction

To develop and validate a nomogram model for discriminating simple intestinal obstruction and strangulated intestinal obstruction, thus providing objective evidence for clinical decision-making. Following pre-established inclusion and exclusion criteria, a retrospective analysis was conducted on the clinical data of 560 patients diagnosed with intestinal obstruction who were admitted to the Emergency Surgery Department of the First Affiliated Hospital of Anhui Medical University between January 1, 2020, and December 31, 2022. The data was subsequently split into a training cohort (n = 393) and a validation cohort (n = 167) using a 7:3 ratio. To identify independent risk and protective factors associated with strangulated intestinal obstruction, a multivariate logistic regression analysis was employed. Based on the identified factors, a nomogram prediction model was constructed. The model's discriminatory ability was assessed using the receiver operating characteristic (ROC) curve, the area under the curve (AUC), and the corrected C-index. The Hosmer-Lemeshow test was utilized to evaluate the model's goodness of fit in both the training and validation cohorts. Calibration curves were generated to assess the model's accuracy in predicting the probability of strangulated intestinal obstruction. Finally, decision curve analysis (DCA) was performed to evaluate the model's potential clinical utility. Multivariate logistic regression analysis identified neutrophil percentage, peritoneal irritation sign, and abdominal fluid as independent risk factors for strangulated intestinal obstruction, while albumin emerged as an independent protective factor. These factors were incorporated into the nomogram, demonstrating high discrimination (AUC of 0.842[95%CI: 0.787-0.897] in the training set and 0.839 [95%CI: 0.742-0.937] in the validation set) and good calibration. The corrected C-index further supported the model's performance in the training (0.833) and validation (0.813) cohorts. The Hosmer-Lemeshow test results (p = 0.759 and p = 0.505, respectively) indicated a good model fit in both cohorts. Calibration curves confirmed the close agreement between the nomogram predictions and actual observations. Finally, DCA corroborated the model's net clinical benefit. The comprehensive nomogram developed in this study emerged as a promising and convenient tool for evaluating the risk of strangulated intestinal obstruction, thereby aiding clinicians in screening the high-risk population.

Prognostic factors to identify resolution of small bowel obstruction without need for operative management: systematic review

OBJECTIVES

To identify imaging, clinical, and laboratory variables potentially prognostic for surgical management of small bowel obstruction.

METHODS

Two researchers systematically reviewed indexed literature 2001-2021 inclusive for imaging, clinical, and laboratory variables potentially predictive of surgical management of small bowl obstruction and/or ischaemia at surgery, where performed. Risk of bias was assessed. Contingency tables for variables reported in at least 5 studies were extracted and meta-analysed to identify strong evidence of association with clinical outcomes, across studies.

RESULTS

Thirty-one studies were ultimately included, reporting 4638 patients (44 to 313 per study). 11 (35%) studies raised no risk of bias concerns. CT was the modality reported most (29 studies, 94%). Meta-analysis of 21 predictors identified 5 strongly associated with surgical intervention, 3 derived from CT (peritoneal free fluid, odds ratio [OR] 3.24, 95%CI 2.45 to 4.29; high grade obstruction, OR 3.58, 95%CI 2.46 to 5.20; mesenteric inflammation, OR 2.61, 95%CI 1.94 to 3.50; abdominal distension, OR 2.43, 95%CI 1.34 to 4.42; peritonism, OR 3.97, 95%CI 2.67 to 5.90) and one with conservative management (previous abdominopelvic surgery, OR 0.58, 95%CI 0.40 to 0.85). Meta-analysis of 10 predictors identified 3 strongly associated with ischaemia at surgery, 2 derived from CT (peritoneal free fluid, OR 3.49, 95%CI 2.28 to 5.35; bowel thickening, OR 3.26 95%CI 1.91 to 5.55; white cell count, OR 4.76, 95%CI 2.71 to 8.36).

CONCLUSIONS

Systematic review of patients with small bowel obstruction identified four imaging, three clinical, and one laboratory predictors associated strongly with surgical intervention and/or ischaemia at surgery.

CLINICAL RELEVANCE STATEMENT

Via systematic review and meta-analysis, we identified imaging, clinical, and laboratory predictors strongly associated with surgical management of small bowel obstruction and/or ischaemia. Multivariable model development to guide management should incorporate these since they display strong evidence of potential utility.

KEY POINTS

• While multivariable models incorporating clinical, laboratory, and imaging factors could predict surgical management of small bowel obstruction, none are used widely. • Via systematic review and meta-analysis we identified imaging, clinical, and laboratory variables strongly associated with surgical management and/or ischaemia at surgery. • Development of multivariable models to guide management should incorporate these predictors, notably CT scanning, since they display strong evidence of potential utility.

Changing patterns and surgical outcomes of small bowel obstruction in the era of minimally invasive surgery for colorectal cancer

INTRODUCTION

This study aimed to investigate whether the incidence, patterns, and surgical outcomes of small bowel obstruction (SBO) have changed in the era of minimally invasive surgery (MIS) for primary colorectal cancer (CRC).

METHODS

Consecutive patients who underwent laparotomy for SBO were divided into MIS and traditional open surgery (TOS) groups based on the previous colorectal cancer operation technique used. The MIS group was selected from 1544 consecutive patients who underwent MIS as a treatment for primary CRCs between 2014 and 2022, while the TOS group was selected from 1604 consecutive patients who underwent TOS as a treatment for primary CRCs between 2004 and 2013. The demographics, clinicopathological features, and surgical outcomes were compared between the two groups.

RESULTS

The SBO incidence in patients who underwent MIS for primary CRC was significantly lower than that in patients who underwent TOS (4.4%, n =68/1544 vs. 9.7%, n =156/1604, P <0.0001). Compared with the TOS group, the MIS group had significantly different ( P <0.0001) SBO patterns: adhesion (48.5 vs. 91.7%), internal herniation (23.5 vs. 2.6%), external herniation (11.8 vs. 1.9%), twisted bowel limbs (4.4 vs. 0.6%), ileal volvulus with pelvic floor adhesion (5.9 vs. 1.9%), and nonspecific external compression (5.9 vs. 1.3%). A subset analysis of patients with adhesive SBO (ASBO) showed that the MIS group tended to ( P <0.0001) have bands or simple adhesions (75.8%), whereas the TOS group predominantly had matted-type adhesions (59.4%). Furthermore, SBO in the MIS group had an acute (<3 months) or early (3-12 months) onset (64.7%), while that in the TOS group ( P <0.0001) had an intermediate or a late onset. When the surgical outcomes of SBO were evaluated, the TOS group had significantly more ( P <0.0001) blood loss and longer operation time; however, no significant difference was observed in the surgical morbidity/mortality (Clavien-Dindo classification ≧3, 11.8 vs. 14.1%, P =0.6367), hospitalization, and readmission rates between the two groups. Postoperative follow-up showed that the estimated 3-year (11.37 vs. 18.8%) and 6-year (25.54 vs. 67.4%) recurrence rates of SBO were significantly lower ( P =0.016) in the MIS group than in the TOS group.

CONCLUSIONS

The wide adoption of MIS to treat primary CRC has led to a lower incidence, altered patterns, and reduced recurrence rates of SBO. Awareness of this new trend will help develop surgical techniques to prevent incomplete restoration of anatomical defects and bowel malalignments specifically associated with MIS for CRC, as well as facilitate timely and appropriate management of SBO complications whenever they occur.