Simethicone to prevent colonic bubbles during CT colonography performed with polyethylene glycol lavage and iohexol tagging: a randomized clinical trial.

OBJECTIVE: The purpose of this study was to determine whether the occurrence of numerous colonic bubbles during CT colonography (CTC) performed with polyethylene glycol cleansing and oral iohexol fecal/fluid tagging could be prevented by use of simethicone. SUBJECTS AND METHODS: Adults with suspected colonic neoplasia who had been randomly assigned to control and simethicone intervention groups underwent CTC after cleansing with 4 L of polyethylene glycol, tagging with 50 mL of 350 mg I/mL oral iohexol, and without (control) or with (intervention) oral administration of 200 mg of simethicone. Colonic segments in the control and intervention groups were evaluated for amount of colonic bubbles during CTC. A 6-point grading system was used in which 0 indicated no bubbles and 5 indicated that more than three fourths of the air-distended mucosa was covered with bubbles. The primary endpoint was a per-patient colonic bubble grade, derived as an average of the segmental grades. RESULTS: Eighty adults with suspected colonic neoplasia were randomly assigned to the control (40 patients) and simethicone intervention (40 patients) groups. A total of 659 colonic segments in the control group and 689 segments in the intervention group were evaluated for amount of colonic bubbles during CTC. The per-patient colonic bubble score was significantly lower in the simethicone intervention group than in the control group. The mean score was 0.0±0.1 (SD) versus 1.2±0.8 (p<0.001; 95% CI for the mean difference, -1.4 to -1.0). In the intervention group, 673 (97.7%) segments were grade 0, and 16 (2.3%) were grade 1. In contrast, in the control group, 226 (34.3%) segments were grade 0; 173 (26.3%), grade 1; 175 (26.6%), grade 2; 45 (6.8%), grade 3; 23 (3.5%), grade 4; and 17 (2.6%), grade 5. CONCLUSION: The colonic bubbles associated with fecal/fluid tagging with iohexol can be successfully prevented by adding simethicone to the colonic preparation.

Malignant rectal obstruction within 5 cm of the anal verge: is there a role for expandable metallic stent placement?

BACKGROUND: Placement of expandable metallic stents (EMS) has been considered contraindicated for patients with malignant rectal obstruction within 5 cm of the anal verge because of the potential problems of anal pain. OBJECTIVE: Our purpose was to investigate the technical feasibility, clinical effectiveness, and safety of EMS placement in patients with malignant rectal obstruction within 5 cm of the anal verge. DESIGN: Retrospective study. SETTING: Single tertiary referral university hospital. PATIENTS: The sites of obstruction included the rectum within 5 cm (range, 25-50 mm) of the anal verge in 16 patients (group A) and more than 5 cm (range, 53-74 mm) in 14 patients (group B). INTERVENTIONS: Placement of 3 types of EMS. MAIN OUTCOME MEASUREMENTS: Complications including pain were evaluated and compared between 2 groups with the Fisher exact test. RESULTS: The overall technical success rate was 100%. Colon perforation occurred in 2 patients, who underwent emergency surgery. Ten (62.5%) of group A and 1 (7.1%) of group B complained of pain (P = .011). In 3 of the 10 patients in group A, the pain disappeared spontaneously within a week or was tolerated by the patients without use of analgesics, although the remaining 7 patients of group A and the 1 patient in group B needed analgesics until death or elective surgery. LIMITATIONS: Retrospective study. CONCLUSIONS: Placement of EMS in patients with malignant rectal obstruction within 5 cm of the anal verge seems feasible and relatively safe and may provide adequate palliation and preoperative decompression of obstruction symptoms. Anal pain was tolerable to the patients with or without use of analgesics.