A novel discriminant formula for the prompt diagnosis of strangulated bowel obstruction

The target sign: a significant CT sign for predicting small-bowel ischemia and necrosis

OBJECTIVE

To investigate the correlation between changes in the thickness and density of diseased small-bowel wall and small-bowel ischemia and necrosis (SBN) on CT imaging when small-bowel obstruction (SBO) occurs.

METHODS

We retrospectively analyzed 186 patients with SBO in our hospital from March 2020 to June 2023. The patients were divided into simple SBO (control group) and SBN (case group) groups. We used logistic regression analysis, the chi-square test, and Fisher's exact test to analyze the correlation between the changes in the thickness and density of the diseased intestinal wall and the SBN. A receiver operating characteristic (ROC) curve was used to calculate the accuracy of the multivariate analysis.

RESULTS

Of the 186 patients with SBO, 98 (52.7%) had simple SBO, 88 (47.3%) had SBN, and the rate of SBN was 47.3% (88/186). Multivariate regression analysis revealed that six CT findings were significantly correlated with SBN (p < 0.05), namely, thickening of the diseased intestinal wall with the target sign (OR = 21.615), thinning of the diseased intestinal wall (OR = 48.106), increase in the diseased intestinal wall density (OR = 13.696), mesenteric effusion (OR = 21.635), decrease in the diseased intestinal wall enhancement on enhanced scanning (OR = 41.662), and increase in the diseased intestinal wall enhancement on enhanced scanning (OR = 15.488). The AUC of the multivariate analysis reached 0.987 (95% CI 0.974-0.999). Specifically, the target sign was easily recognizable on CT images and was a significant CT finding for predicting SBN.

CONCLUSION

We identified 6 CT findings that were significantly associated with SBN, and may be helpful for clinical treatment.

Ischemia prediction score (IsPS) in patients with strangulated small bowel obstruction: a retrospective cohort study

BACKGROUNDS

Intestinal ischemia of strangulated small bowel obstruction (SSBO) requires prompt identification and early intervention. This study aimed to evaluate the risk factors and develop a prediction model of intestinal ischemia requiring bowel resection in SSBO.

METHODS

This was a single-center, retrospective cohort study of consecutive patients underwent emergency surgery for SSBO from April 2007 to December 2021. Univariate analysis was performed to identify the risk factors for bowel resection in these patients. Two clinical scores (with contrasted computed tomography [CT] and without contrasted CT) were developed to predict intestinal ischemia. The scores were validated in an independent cohort.

RESULTS

A total of 127 patients were included, 100 in the development cohort (DC) and 27 in the validation cohort (VC). Univariate analysis showed that high white blood cell count (WBC), low base excess (BE), ascites and reduced bowel enhancement were significantly associated with bowel resection. The ischemia prediction score (IsPS) comprised 1 point each for WBC ≥ 10,000/L, BE ≤ -1.0 mmol/L, ascites, and 2 points for reduced bowel enhancement. The simple IsPS (s-IsPS, without contrasted CT) of 2 or more had a sensitivity of 69.4%, specificity of 65.4%. The modified IsPS (m-IsPS, with contrasted CT) of 3 or more had a sensitivity of 86.7%, specificity of 76.0%. AUC of s-IsPS was 0.716 in DC and 0.812 in VC, and AUC of m-IsPS was 0.838 and 0.814.

CONCLUSION

IsPS predicted possibility of ischemic intestinal resection with high accuracy and can help in the early identification of intestinal ischemia in SSBO.

Prediction and management of strangulated bowel obstruction: a multi-dimensional model analysis

BACKGROUND

Distinguishing strangulated bowel obstruction (StBO) from simple bowel obstruction (SiBO) still poses a challenge for emergency surgeons. We aimed to construct a predictive model that could distinctly discriminate StBO from SiBO based on the degree of bowel ischemia.

METHODS

The patients diagnosed with intestinal obstruction were enrolled and divided into SiBO group and StBO group. Binary logistic regression was applied to identify independent risk factors, and then predictive models based on radiological and multi-dimensional models were constructed. Receiver operating characteristic (ROC) curves and the area under the curve (AUC) were calculated to assess the accuracy of the predicted models. Via stratification analysis, we validated the multi-dimensional model in the prediction of transmural necrosis both in the training set and validation set.

RESULTS

Of the 281 patients with SBO, 45 (16.0%) were found to have StBO, while 236(84.0%) with SiBO. The AUC of the radiological model was 0.706 (95%CI, 0.617-0.795). In the multivariate analysis, seven risk factors including pain duration ≤ 3 days (OR = 3.775), rebound tenderness (OR = 5.201), low-to-absent bowel sounds (OR = 5.006), low levels of potassium (OR = 3.696) and sodium (OR = 3.753), high levels of BUN (OR = 4.349), high radiological score (OR = 11.264) were identified. The AUC of the multi-dimensional model was 0.857(95%CI, 0.793-0.920). In the stratification analysis, the proportion of patients with transmural necrosis was significantly greater in the high-risk group (24%) than in the medium-risk group (3%). No transmural necrosis was found in the low-risk group. The AUC of the validation set was 0.910 (95%CI, 0.843-0.976). None of patients in the low-risk and medium-risk score group suffered with StBO. However, all patients with bowel ischemia (12%) and necrosis (24%) were resorted into high-risk score group.

CONCLUSION

The novel multi-dimensional model offers a useful tool for predicting StBO. Clinical management could be performed according to the multivariate score.

[Preoperative diagnosis of intestinal ischemia in small bowel obstruction. Only computed tomography? A multiple-center observational study]

OBJECTIVE

To evaluate the accuracy of clinical, laboratory and instrumental methods for diagnosis of intestinal ischemia following small bowel obstruction in emergency hospitals.

MATERIAL AND METHODS

Multiple-center observational retrospective study enrolled 158 consecutive patients with benign small bowel obstruction (SBO) treated at four hospitals between May 2017 and December 2019. The role of clinical, laboratory and instrumental diagnostic methods for intestinal ischemia was analyzed. We assessed the impact of CT and contrast-enhanced X-ray examination on survival of patients.

RESULTS

Laboratory parameters as criteria of ischemia following SBO were similar (leukocytosis >14·10⁹/l (p=1.0), serum lactate >2.0 mmol/l (p=0.28), heart rate >90/min (p=0.71) and fever (p=0.74)). The only laboratory indicator with significant differences was serum sodium. Decrease in leukocytosis over time was less common in patients with ischemia (25% vs. 61.3%, p=0.012). Univariate Kaplan-Meier analysis did not establish the effect of CT on survival (7.8% [95% CI 7.6-8.0] vs. 6.5% [95% CI 6.3-6.6], p=0.786). Logistic regression revealed 6.4-fold higher chance of accurate diagnosis (ischemia/non-ischemia) in case of CT-based conclusion of ischemia (95% CI 0.025-0.85). Univariate analysis showed that the use of water-soluble contrast for adhesive SBO was associated with lower mortality (4.1% [95% CI 4.0-4.2] vs. 14.3% [95% CI 13.7-14.9], p=0.032) without assessing the comparability of groups.

CONCLUSION

Routine laboratory tests were not specific for intestinal ischemia. Therefore, they should not be considered as the only criteria for surgical tactics in intestinal obstruction. Only CT showed acceptable diagnostic accuracy, and, apparently, only this method has real prospects for improving the quality of diagnosis due to technical support, training of surgeons and specialists for diagnosis.