Predictors of severity in ischemic colitis: Usefulness of early ultrasonography

PURPOSE

The main objective was to evaluate the usefulness of early ultrasonography for determining prognosis of patients with ischemic colitis.

MATERIALS AND METHODS

We reviewed the histories of patients with diagnosis of ischemic colitis over a period of 11 years. Two hundred twenty nine patients with ischemic colitis were included. Demographic, clinical, laboratory and sonographic findings were retrospectively analyzed. Patients were divided into two groups according to the outcome: mild (those who improved with conservative treatment) or severe (those who died or required surgery), and the findings of each group were compared. In addition, we developed a predictive model of multivariate logistic regression analysis, and then it was validated in a different population of 58 consecutive patients with ischemic colitis.

RESULTS

The mild ischemic colitis group consisted of 184 patients (age 74,7±8,8years), and the severe group of 45 patients (age 78,6±7,7years). More pancolitis (p=0.005), altered pericolic fat (p=0.032) and free fluid (p=0.013) was observed in the severe ischemic colitis group compared with the mild group. Severe ischemic group had lower wall thickness (p=0.020) and higher resistive index than mild group (p=0.025). Multivariate analysis identified as protective factors to severe ischemic colitis: pain (p=0.026), diarrhea (p=0.034), rectal bleeding (p=0.000), and hypertension (p=0.001). Altered pericolic fat (p=0.008) and pancolitis (p=0.017) were sonographic findings significantly related to severe ischemic colitis. Our model correctly classified 88.4% of the study patients and 89.6% of the population of 58 patients used in validation.

CONCLUSIONS

Sonographic features with clinical findings can predict the outcome of ischemic colitis. Our predictive model could differentiate properly between patients with mild or severe ischemic colitis.

Sonographic findings in ischemic colitis in 58 patients

OBJECTIVE

The purpose of this study was to describe the sonographic findings of 58 patients with proven ischemic colitis and to evaluate whether any of the findings are related to the presence or development of transmural necrosis.

MATERIALS AND METHODS

We reviewed the histories of patients diagnosed with ischemic colitis over a period of 5.5 years. Sixty-two patients had undergone sonographic examinations. The spectrum of sonographic findings in ischemic colitis was based on the original imaging report, with an analysis of the presence of colonic abnormalities and their associated alterations. In the second part of the study, we divided the patients into two groups according to the presence or absence of transmural necrosis, and the sonographic findings of each group were compared. Ten patients had sonographic follow-up studies during their hospital stay.

RESULTS

The prospective sensitivity of sonography for the characterization of colonic abnormalities was 93.5% (58/62 patients). Segmental involvement was detected in 57 of the 58 patients, with left-sided colitis in 47 (81%). The mean length of bowel involved was 19 cm, with a mean wall thickness of 7.6 mm. Colon wall stratification was preserved in 38 patients (66%). Altered pericolic fat was observed in 16 patients (28%). Absence of or barely visible color Doppler flow in the thickened bowel wall was recorded in 80% of patients. Altered pericolic fat was the only sonographic variable significantly associated with the presence of transmural necrosis (p = 0.004). Improvement as assessed on sonography was observed in all patients with a good clinical course. In patients with transmural necrosis, sonography did not show improvement.

CONCLUSION

Sonography is a valuable technique for the detection of colonic abnormalities resulting from ischemic colitis. In this study, altered pericolic fat or the absence of improvement in sonographic follow-up studies were factors associated with transmural necrosis.