Radiofrequency ablation of Barrett's esophagus: outcomes of 429 patients from a multicenter community practice registry.

BACKGROUND AND STUDY AIMS: The use of radiofrequency ablation (RFA) for complete eradication of Barrett's esophagus has shown promise in trials conducted at predominantly tertiary academic centers; however less is known regarding outcomes in the community. We evaluated the safety and efficacy of RFA for Barrett's esophagus delivered in a community practice setting. PATIENTS AND METHODS: This was a multicenter registry conducted in community-based gastroenterology practices. Patients had confirmed intestinal metaplasia with or without dysplasia on biopsy of a Barrett's esophagus. Intervention was step-wise RFA with follow-up esophageal biopsies. Endpoints were histology-based; complete response was defined as all biopsies at most recent endoscopy negative for intestinal metaplasia (CR-IM) or dysplasia (CR-D). Three cohorts were reported: 1) safety cohort, all patients; 2) efficacy cohort A, patients with at least one biopsy session after initial treatment; 3) efficacy cohort B, patients with at least one biopsy session > or = 1 year after initial treatment. RESULTS: The safety cohort included 429 patients (71 % men, median age 59 years, median Barrett's segment 3.0 cm). There were no serious adverse events (bleeding, perforation, death), and a stricture occurred after 1.1 % of cases (2.1 % of patients). In efficacy cohort A (n = 338), CR-IM and CR-D were achieved in 72 % and 89 % of patients, respectively (median follow-up 9 months). In efficacy cohort B (n = 137), CR-IM and CR-D were achieved in 77 % and 100 % of patients, respectively (median follow-up 20 months). CONCLUSIONS: In this multicenter registry conducted at four community-based practices, the observed safety and efficacy outcomes associated with RFA for Barrett's esophagus are comparable to those previously reported in multicenter trials from predominantly tertiary academic centers.

Myoelectric activity of the small intestine during morphine dependence and withdrawal in rats.

We investigated the effect of morphine dependence on the migrating myoelectric complex (MMC) of the small intestine, whether bacterial overgrowth developed in morphine-dependent rats, and the effect of naloxone, 0.5 mg/kg sc, and methylbromide naltrexone, 1.0 mg/kg sc, a peripheral opioid antagonist, on the MMC in morphine-naive and morphine-dependent rats. We also evaluated intestinal motility during naloxone-induced withdrawal in animals pretreated with clonidine, 100 micrograms/kg sc. Intestinal myoelectric activity was monitored by four indwelling electrodes in unanesthetized, fasted rats. D-[14C]xylose breath tests were performed before and after morphine-pellet implantation to evaluate the presence of bacterial overgrowth of the small intestine. Naloxone had no effect on myoelectric activity of the small intestine in morphine-naive rats. Cycling activity fronts were present in morphine-dependent animals, but there was a significant prolongation of activity front periodicity and slowing of the propagation velocity. No significant increase in 14CO2 excretion was noted in the morphine-dependent rats. After injection of naloxone, the morphine-dependent rats had a marked increase in spike activity with no identifiable activity fronts for 89 +/- 8 min. Similarly, methylbromide naltrexone disrupted activity fronts, but for a significantly shorter period. Clonidine prevented the marked increase in spike activity that occurred during naloxone-induced withdrawal. We conclude from our studies that myoelectric activity of the small intestine develops incomplete tolerance to morphine; bacterial overgrowth is not a feature of morphine dependence in the rat; alterations of intestinal myoelectric activity are a component of the opiate withdrawal syndrome, and they appear at least partially mediated by a peripheral mechanism that can be suppressed by an alpha 2-adrenergic agonist.