Computed-tomography angiography in arterial acute intestinal ischemia: prognostic interest of vascular semiology.

PURPOSE: To investigate vascular features on abdominal Computed-Tomography Angiography (CTA) correlated with 48-h mortality in patients who underwent arterial acute intestinal ischemia (AAII) surgery. The secondary objective was to create a prognostic score on the 48-h mortality after surgery, based on the most relevant signs. METHOD: We included 104 patients who underwent surgery for acute mesenteric ischemia. 2 radiologists retrospectively blind reviewed the preoperative CTA scans. They used a standardized analysis grid for the arterial and venous vascular signs described in angiography. When signs were present, the affected abdominal quadrant was specified in coronal reconstruction. Each sign was analyzed for 48-h mortality on CTA. A score based on signs correlated with early mortality was developed and evaluated by ROC curve analysis. RESULTS: 22 patients died within 48 h. The number of superior mesenteric artery (SMA) branches was significantly reduced in deceased patients (p = 0.006). Other prognostic factors associated with 48-h mortality were decreased venous return in area number 1 corresponding to right colic flexure, proximal half of the transverse colon, proximal ileum (p = 0.04) and decreased venous return in more than 2 zones (p = 0.01). The weighted AAII48 score included 1 protective clinical item and 5 radiological items. The area under the ROC curve was 0.784 with, for a 6-point threshold value, a sensitivity of 68% and a specificity of 77%. The intraclass correlation coefficient for interobserver reproducibility of the score was 0.81 [95% CI 0.73; 0.87]. CONCLUSION: Three vascular signs on CTA were found to be prognostic factors for early mortality: SMA branches number ≤ 5 (p = 0.006), decreased venous return in area 1 (p = 0.04), and > 2 areas of decreased venous return (p = 0.01). They were incorporated into the AAII48 score. This score could help to identify patients at risk and to adapt subsequent management.