Purpose: To describe the appearance, prevalence, and possible as-sociations of colonic wall redundancy in patients with cys-tic fibrosis (CF).
Materials and Methods:The institutional review board approved this HIPAA-com-pliant study. Abdominal computed tomographic (CT) im-ages of 38 consecutive patients with CF and a control group of 38 consecutive potential renal donors were retro-spectively identified. Three readers independently re-corded presence and location of colonic wall redundancy and wall thickness of the ascending, transverse, and descending colon. Interobserver agreement for colonic wall redundancy was determined with the k statistic. Colonic wall thicknesses were compared between patient groups with the Student t test. Proportions of adult and pediatric patients with and those without colonic wall redundancy and prevalence of specific gene mutations were compared between groups with the Fisher exact test. CT findings were compared with radiologic reports and clinical records.
Results:Each reviewer found colonic wall redundancy in I 1 of 28 adults with CF but in none of the children with CF (P < .05 for each reviewer). There was excellent interobserver agreement for identification of colonic wall redundancy ( = 0.91, P < .001). Mean thickness of the wall of the ascending colon was significantly greater in patients with CF who had colonic wall redundancy (4.0 mm) than in those without this finding (1.8 mm, P < .03) or in control patients (1.2 mm, P < .05). Among adult patients with CF, ΔF508 mutation was the predominant mutant allele in 10 of 13 patients with normal colons at CT, whereas more uncommon non-ΔF508 mutations were seen in seven of 10 patients with colonic wall redundancy (P < .05). Asymp-tomatic colonic wall redundancy at CT was prospectively misinterpreted as acute colonic disease in five adult patients.
Conclusion:Proximal colonic wall redundancy is seen frequently in adults with CF and may be more common in those with non-ΔF508 CFTR gene mutations. This finding provides a starting point for further investigation of the molecular basis of colonic phenotype in CF.
