The utility of a CT grading scale in deciding on surgical intervention for patients with suspected small bowel obstruction.

Background: A grading system was developed for computerized tomography (CT) scans evaluating patients with suspected small bowel obstruction (SBO). We hypothesized that patients with a higher grade of suspected SBO on CT scan would be more likely to require surgical intervention.

Methods: Retrospective chart review of patients who presented to the Emergency Room (ER) who had a CT of the abdomen and pelvis for suspected SBO. Patients were divided into 5 groups: Grade 1 (SBO unlikely), Grade 2 (probable partial or early SBO), Grade 3 (probable high grade SBO), Grade 4 (SBO with changes concerning for ischemia) and Not Graded.

Results: The CT scans of 655 patients were graded. Of the 22 patients with a grade 1 SBO, only 1 went for surgery (4.5 %). For grade 2 patients, 23 out of 299 had an operation (7.7 %), for grade 3 it was 84 out of 299 (28.1 %) and for grade 4 SBO, 25 out of 35 patients (71.4 %) had surgery. The value is <0.00001. The three most common intraoperative findings were SBO obstruction from adhesions alone (48 % of cases), followed by incarcerated hernias (12 %) and ischemic bowel (9 %). Only 8 cases out of 133 operations (6 % of total) had no findings at time of surgery other than dilated bowel.

Conclusions: The CT grading scale for SBO developed at our institution shows excellent correlation between grade and going for surgery, with few negative results, and can be a useful tool among other factors for general surgeons when deciding whether or not to operate on a patient with suspected SBO.