Abdominal Multidetector Computed Tomography for Suspected Small-Bowel Obstruction: Multireader Study Comparing Radiologist Performance for Predicting Surgical Outcomes

Correlation of CT findings with intra-operative outcome in closed-loop small bowel obstruction (CL-SBO)

PURPOSE

To correlate CT-findings in patients with closed-loop small bowel obstruction (CL-SBO) with perioperative findings, to identify patients who require immediate surgical intervention. Secondary purpose was to substantiate the role of radiologists in predicting perioperative outcome.

METHODS

Data were retrospectively obtained from patients with surgically confirmed CL-SBO, between September 2013 and September 2019. Three radiologists reviewed CTs to assess defined CT features and predict patient outcome for bowel wall ischemia and necrosis using a likelihood score. Univariate statistical analyses were performed and diagnostic performance parameters and interobserver agreement were assessed for each feature.

RESULTS

Of 148 included patients, 28 (19%) intraoperatively had viable bowel and 120 (81%) had bowel wall ischemia or necrosis. Most CT characteristics, as well as the likelihood of ischemia and necrosis, found fair or moderate multirater agreement. Increased attenuation of bowel wall and mesenteric vessels on non-contrast-enhanced CT had a specificity for bowel ischemia or necrosis of 100% (sensitivity respectively 48% (p < 0.001) and 21% (p = 0.09)). Mesenteric edema had high sensitivity for ischemia or necrosis (90%), but specificity of only 26% (p < 0.001). For mesenteric fluid, sensitivity was 60% and specificity 57% (p = 0.004). Decreased enhancement of bowel wall in both arterial and PV-phase showed significant correlation, respectively a sensitivity of 58% and 42%, and specificity of 88% and 79% (both p < 0.001). Likelihood of both ischemia and necrosis were significantly correlated with perioperative outcome (p < 0.001).

CONCLUSION

CT findings concerning mesenteric and bowel wall changes, as well as radiologists' judgement of likelihood of ischemia and necrosis are significantly correlated with perioperative outcome of bowel wall ischemia and necrosis in patients with CL-SBO.

Value of MDCT and Clinical and Laboratory Data for Predicting the Need for Surgical Intervention in Suspected Small-Bowel Obstruction

OBJECTIVE

The purpose of this article is to assess the value of a large panel of clinical and MDCT variables in patients with suspected small-bowel obstruction (SBO) for predicting urgent surgical intervention (< 72 hours), bowel ischemia, and bowel resection.

MATERIALS AND METHODS

MDCT studies performed at admission for 179 nonconsecutive adults (mean age, 55.8 years; 86 men and 93 women) with suspected SBO were retrospectively reviewed by three board-certified radiologists. In addition to assessing individual CT features, each radiologist scored the overall likelihood of each main outcome measure using a 5-point scale. All relevant clinical and laboratory data were abstracted from electronic medical record review. Univariate and multivariate analyses were performed.

RESULTS

Among all 179 patients with suspected SBO, 56 (31.3%) underwent surgical intervention within 72 hours, 10 (5.6%) had ischemia at surgery, and nine (5.0%) required small-bowel resection. On univariate analysis, multiple CT findings were highly significant (p < 0.01) for predicting the main surgical outcomes, including degree of obstruction, 5-point radiology likelihood scores, and the presence of a transition point, closed loop, and mesenteric congestion. None of the objective clinical or laboratory variables (including serum lactate level) reached this level of significance. At multivariate analysis, forward stepwise logistic regression with 0.05 significance level cutoff included both degree of obstruction (p < 0.001) and closed loop (p < 0.01), with the presence of a transition point showing a trend toward significance (p = 0.081).

CONCLUSION

A number of findings at abdominal MDCT are associated with the need for surgery and other important surgical outcomes in patients with suspected SBO. Overall radiologist impression of need for surgical intervention was a better predictor than any clinical or laboratory parameter.