[Usefulness of CT colonography in the preoperative evaluation of patients with distal occlusive colorectal carcinoma].
OBJECTIVE
To evaluate the role of preoperative virtual colonoscopy to study the proximal colon in patients with distal occlusive carcinomas, diagnosed by conventional colonoscopy.


METHODS
We examined 19 patients aged 46 to 83 years (13 men and 6 women) with distal occlusive colorectal carcinomas diagnosed by conventional colonoscopy, who were preoperatively studied with virtual colonoscopy. Patients with acute bowel obstruction were excluded. Results were compared with the findings of preoperative conventional colonoscopy and barium enema examination, intraoperative colon palpation, histopathologic outcome, postoperative conventional colonoscopy and barium enema examination.


RESULTS
Virtual colonoscopy identified all 19 distal occlusive colon carcinomas and 22 synchronous lesions, 2 cancers (prevalence 10,6%) and 20 polyps (prevalence 68,4%). Both synchronous cancers were confirmed intraoperatively by direct palpation. Postoperative conventional colonoscopy, which was performed in 18 patients, confirmed the presence of 15 polyps in 12 patients. Three subcentimeter polyps were removed during conventional colonoscopy and were missed at virtual colonoscopy. Two polyps shown by virtual colonoscopy were not found at conventional colonoscopy. Postoperative barium enema was performed in three patients and confirmed three polyps identified at virtual colonoscopy. Preoperative barium enema was performed in five patients and failed to adequately demonstrate the proximal colon. Virtual colonoscopy showed a sensitivity of 87% and a specificity of 75%.


CONCLUSIONS
Virtual CT colonoscopy can be considered an important diagnostic technique to evaluate preoperatively the proximal colon in patients with distal occlusive carcinomas,as it gives better results than barium enema or conventional colonoscopy, as well as being well tolerated and less invasive.
Galia
M
M
Istituto di Radilogia P. Cignolini, Università degli Studi, Palermo, Italy. maxgall@tin.it
Midiri
M
M
Carcione
A
A
Cusmà
S
S
Bartolotta
T V
TV
Angileri
T
T
De Maria
M
M
Lagalla
R
R
D000230:Adenocarcinoma / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000601:surgery; D000368:Aged; D000369:Aged, 80 and over; D003110:Colonic Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000601:surgery; D003111:Colonic Polyps / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000601:surgery; D003113:Colonoscopy / Q000379:methods*; D003251:Constriction, Pathologic / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000601:surgery; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D014057:Tomography, X-Ray Computed / Q000379:methods