Antireflux role of free muscle transplantation. Experimental study in a reflux esophagitis rat model

Purpose: Experimental work on free muscle transplantation has resulted in s ome successful clinical applications. After a previous experimental study t hat established the viability of this procedure on the distal esophagus of the rat, we investigated the antireflux efficacy of free muscle transplanta tion on the distal esophagus in a reflux esophagitis rat model. Methods: Two groups of Sprague-Dawley rats were submitted to a reflux-induc ing operation. Thirteen animals underwent esophagojejunostomy only (EJ) and fourteen were submitted to esophagojejunostomy plus free muscle transplant ation of plantaris on the distal esophagus (ETx). Eight weeks later, the es ophagi of survivors were removed after sacrifice (EJ, n = 10; ETx, n = 10) and the macroscopic longitudinal extension (mm) and the histological grade (1-4) of esophagitis evaluated. Results: All esophageal specimens of both groups had esophagitis. However, the extent of esophagitis (median: ETx: 23 vs EJ: 32) and the frequency of high grades of esophagitis (ETx: 30% vs. EJ: 100%) were significantly lower in the ETx group (p = 0.005 and p = 0.001, respectively). All except one E Tx subject presented with an extent and/or a grade of esophagitis which was less than the EJ subjects' lowest values. Conclusions: Experimental free muscle transplantation on the distal esophag us seems to have antireflux function, thus its therapeutic implications des erve further investigation. The incomplete efficacy of the procedure may su ggest that a putative anatomic sphincter per se is not enough to promote an effective antireflux mechanism.