CT colonography after metallic stent placement for acute malignant colonic obstruction.
OBJECTIVE
To evaluate the feasibility of using computed tomographic (CT) colonography for preoperative examination of the proximal colon after metallic stent placement in patients with acute colon obstruction caused by colorectal cancer.


METHODS
Institutional review board approval was obtained, and patient informed consent was waived. Fifty patients (mean age +/- standard deviation, 58.5 years +/- 11.7), who demonstrated no postprocedural complication after successful placement of self-expandable metallic stents to treat acute colon obstruction caused by cancer, underwent CT colonography 1-43 days (median, 5 days) after stent placement. CT colonography was performed after cathartic preparation by using magnesium citrate (n = 20) or sodium phosphate (n = 3), combined with oral bisacodyl, or by using polyethylene glycol (n = 27). Fecal/fluid tagging was achieved by using 100 mL of meglumine diatrizoate. The colon was distended by means of pressure-monitored CO(2) insufflation. The sensitivity and specificity of CT colonography in evaluating the colon proximal to the stent and CT colonography-related complications were assessed. The 95% confidence intervals (CIs) were calculated for proportional data.


RESULTS
Per-lesion and per-patient sensitivities of CT colonography for lesions 6 mm or larger in diameter in the colon proximal to the stent were 85.7% (12 of 14 lesions; 95% CI: 58.8%, 97.2%) and 90% (nine of 10 patients; 95% CI: 57.4%, 99.9%), respectively. CT colonography depicted all synchronous cancers (two lesions) and advanced adenomas (five lesions). Per-patient specificity for lesions 6 mm and larger in the proximal colon was 85.7% (18 of 21 patients; 95% CI: 64.5%, 95.9%). CT colonography did not generate any false diagnosis of synchronous cancer. False-positive findings at CT colonography did not result in a change in surgical plan for any patients. No CT colonography-associated stent dislodgment/migration or colonic perforation occurred in any patient (95% CI: 0%, 6.2%).


CONCLUSIONS
CT colonography is a safe and useful method for preoperative examination of the proximal colon after metallic stent placement in patients with acute colon obstruction caused by cancer. (c) RSNA, 2010.
Cha
Eun-Young
EY
Department of Radiology and Research Institute of Radiology and Department of Surgery, University of Ulsan College of Medicine, Asan Medical Center, 388-1 Poongnap-Dong, Songpa-Gu, Seoul 138-040, Korea.
Park
Seong Ho
SH
Lee
Seung Soo
SS
Kim
Jin Cheon
JC
Yu
Chang Sik
CS
Lim
Seok-Byung
SB
Yoon
Sang Nam
SN
Shin
Yong Moon
YM
Kim
Ah Young
AY
Ha
Hyun Kwon
HK
D000208:Acute Disease; D000368:Aged; D003110:Colonic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D023881:Colonography, Computed Tomographic / Q000379:methods*; D003287:Contrast Media; D005260:Female; D006801:Humans; D007415:Intestinal Obstruction / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D007472:Iohexol / Q000031:analogs & derivatives; D008297:Male; D008670:Metals; D008875:Middle Aged; D011857:Radiographic Image Interpretation, Computer-Assisted; D012015:Reference Standards; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D015607:Stents
D003287:Contrast Media; D008670:Metals; D007472:Iohexol; C038192:iopromide