Value of water enema computed tomography in elderly symptomatic patients

Colonoscopy remains the gold standard for the examination of the colon. However, its use in the elderly is not well tolerated, and there is often a need for general anaesthesia, thus increasing the risk, especially if there are co-morbidities. Water enema computed tomography has been suggested to be a satisfactory alternative as a non-invasive, fast and effective means for the diagnosis of colorectal supra-centimetric lesions. The aim of our study was to assess the performance of water enema computed tomography as first-line examination by calculating its negative predictive value (NPV) for the diagnosis of supra-centimetric lesions in symptomatic elderly referred to colonoscopy. This was a prospective study including 57 symptomatic patients older than 65 years. All patients were explored by water enema computed tomography at first, followed by colonoscopy, and responded to a questionnaire on the tolerance to the preparation and both procedures. The mean age of patients was 73 years. The M:F sex ratio was 1.59. The most frequent indication for colonoscopy was bowel disorders associated with abdominal pain (30%). Water enema computed tomography allowed the diagnosis of tumours (n = 2), polyps (n = 6), diverticulosis (n = 7), inflammatory wall thickening (n = 1) and extra-colic lesions (n = 28). NPV of water enema computed tomography for supra-centimetric lesions was 96.5%. Sensitivity and specificity were 87.3% and 98%, respectively. However, for sub-centimetric lesions, water enema computed tomography had a low sensitivity estimated at 6%, specificity at 89.9%, positive predictive value at 91.9% and NPV at 27.7%. Water enema computed tomography has proven to be a valuable and non-invasive method indicated as a first-line examination in case of colonic symptoms in the elderly to diagnose supra-centimetric lesions.