Endoscopic implantation of a biopolymer in the lower esophageal sphincter for gastroesophageal reflux
Gastroesophageal reflux disease (GERD) is the most frequent disorder of the esophagus. The causes of GERD include mainly lower esophageal sphincter (LES) dysfunction, with a decreased resting LES pressure and increased frequency of transient relaxations. Most of the patients with GERD can be adequately managed with PPI but symptom relapse is common after cessation of medical treatment, thus committing many patients to lifelong therapy. For patients who need continuous medical therapy, antireflux surgery, until recently, is the single alternative to lifelong treatment. Despite that, only a small minority of patients undergo surgical fundoplication, since both physicians and patients are cautious about a surgical procedure which, though effective, has a significant rate of morbidity and postoperative complications.
A nonsurgical means of controlling GERD that would avoid the shortcomings of medical and surgical therapy would be desirable. To this end, endoscopic submucosal injections at the level of the cardia, using bovine collagen or Teflon were attempted in the past, with transient encouraging results in terms of symptoms and LES pressure improvements. However, the promising results were short lived since collagen was biodegraded and Teflon particles tended to migrate from the injection site.
A pilot study was conducted in 15 patients with GERD needing continuous PPI therapy who accepted to receive injections of a biocompatible, non-biodegradable polymer (Ethylene-Vinyl-Alcohol copolymer, EVA, Enteryx) into the muscle of the cardia . Primary endpoints were the safety of the procedure, the effect on LES pressure and the stability of the injected material. Secondary endpoint was the effect of treatment on heartburn score evaluated off PPI.
EVA injection into the cardia resulted in the creation of a circular diffusion of the product and in an increase in LES pressure in most of the cases, at 1 month, which was sustained after a median follow-up of 6 (range 4-12) months. This was also associated with a sustained reduction of the heartburn score evaluated off PPI. Nine of the 15 patients had more than 50 % of the material remaining in place at the second follow-up. Only 2 had lost more than 75 % of the EVA injected. Only 4/15 patients had to go back on PPI. Mild retrosternal discomfort was observed in 8/15 patients, always disappearing after a maximum of 3 days. 84 patients have been now enrolled in a multicentric FDA-approval study. The criteria for inclusion were similar to those of the pilot study. At 3 months, 72/84 (85.7 %) were still off PPIs and at 6 months, 37 of the 43 patients currently available (86 %) were off PPI. The mean GERD-HQRL score off PPI was 25.5 at baseline and 8.2, 5.6 and 7.1 at 1, 3 and 6 months respectively. At 6 months, 27/37 patients had a normalized or = 25 % reduction of pH-measure and 16/37 had a normalized pH-metry.
In conclusion, EVA implantation in the muscle of the cardia is feasible and safe. In a pilot study, it led to a sustained increase in resting LES pressure. This was associated with a sustained improvement of heartburn score measured off PPI in most of the patients previously needing continuous therapy.
1. DEVIERE J, PASTORELLI A, LOUIS H, MAERTELAER V de, LEHMAN G, LE MOINE O, SILVERMAN D and COSTAMAGNA G. – Endoscopic implantation of a biopolymer in the lower esophageal sphincter for gastroesophageal reflux: a pilot study. Gastrointestinal Endoscopy, March 2002 ; 55.