Larger amounts of nitrite and nitrate-reducing bacteria in megaesophagus of Chagas' disease than in controls.

In the megaesophagus of Chagas' disease, chronic esophagitis is caused by stasis of swallowed food and saliva. In this environment, the overgrowth of aerobic and anaerobic bacteria, including nitrate-reducing bacteria, is observed. The reduction of nitrate into nitrite by the action of these bacteria has been associated with the formation of volatile nitrosamines in different situations of gastric bacterial overgrowth. We have hypothesized that this phenomenon could occur in the esophageal lumen of patients with megaesophagus. To evaluate the concentration of nitrite, the presence of volatile nitrosamines and the concentration of nitrate-reducing bacteria in the esophageal lumen of patients with non-advanced megaesophagus of Chagas' disease and in a group of patients without esophageal disease. Fifteen patients with non-advanced megaesophagus [megaesophagus group (MG)] and 15 patients without any esophageal disease [control group (CG)] were studied. Saliva samples were taken for nitrate and nitrite quantitative determination and esophageal stasis liquid samples were taken for nitrate and nitrite quantitative determination, volatile nitrosamines qualitative determination and reductive bacteria quantitative determination. MG and CG were equivalent in nitrate and nitrite saliva concentration and in nitrate esophageal concentration. Significant difference was found in nitrite (p = 0.003) and reductive bacteria concentration (p < 0.0001), both higher in MG. Volatile nitrosamines were identified in three MG patients and in none of the CG patients, but this was not significant (p = 0.113). There is a higher concentration of reductive bacteria in MG, responsible for the rise in nitrite concentration at the esophageal lumen and, eventually, for the formation of volatile nitrosamines.

Laparoscopic mesh repair antireflux surgery for treatment of large hiatal hernia.

SUMMARY: One of the most frequently occurring anatomic failures after laparoscopic fundoplication is migration of the wrap into the chest, with or without disruption. This so-called 'slipped' Nissen fundoplication may be the result of inadequate closure of the diaphragmatic crura or rupture of the sutures or disruption of the muscle fibers approached. From January 2000 to December 2002, a total of seven patients (four male) with a mean age of 56 years (range 22-72 years), were considered for laparoscopic antireflux procedure using DACRON mash to reinforce the crural hiatal closure. The patients were operated under general anesthesia; laparoscopy was performed by classical approach with five trocars. The mean operative time was 120 minutes (range 40-240 min). There were no deaths. The average of postoperative hospital stay was 3.5 days (range, 3-5). Patients returned to normal activities usually on postoperative day 10 (range, 7-15). The follow-up time was at least 2 years. There was only one late complication related to the use of DACRON mesh at the hiatus, due to migration of the mesh into the esophageal lumen causing disphagia. In conclusion the mesh repair antireflux surgery is a good alternative for closing the diaphragmatic defect in large hiatal hernias or to correct this problem in case of recurrence or Barrett's esophagus.

Experimental esophageal carcinogenesis: technical standardization and results.

The aim of this research was to determine the occurrence of epidermoid carcinoma of the esophagus induced by diethylnitrosamine (DEN) in Wistar rats. DEN was administered (250-300 g) in drinking water (10 mg/kg body weight) to four groups of rats for 72 h/week, for a duration of 90, 120, 150, or 200 days (groups T90, T120, T150, and T200). Ten animals whose drinking water did not contain DEN constituted the control group. All rats were sacrificed and their esophaguses studied macro- and microscopically. The control group did not exhibit either carcinomas or preneoplasic lesions. The T120 and T200 groups presented, respectively, 47 and 58 in situ carcinomas; 1 and 20 submucosal carcinomas (P < 0.05); 4 and 17 microinvasive carcinomas (P < 0.05); 4 and 11 advanced carcinomas (P < 0.05); and 1 and 1 cases of benign hyperplasia. Pulmonary and liver carcinomas were also found in the T200 group. The majority of advanced macroscopic lesions in the T200 group were polypoid, exophytic, and not microscopically invasive in the esophageal wall. This research confirms the effectiveness of the DEN in bringing about carcinogenesis in the Wistar rat esophagus and also shows that the lesions are dosage dependent.