An Experimental Study of the Effectiveness of Various Antireflux Operations

Abstract

After a hypotensive lower esophageal sphincter was created in cats by circular myectomy of the distal esophagus, a comparative study was performed of the sphincter-enhancing operations currently in use: the Nissen fundoplication, the Belsey Mark IV, and the Hill posterior gastropexy. Subdiaphragmatic transposition of the myectomized segment was included to assess the effectiveness of intraabdominal positioning on lower esophageal sphincter competence. The mean lower esophageal sphincter pressure after Nissen fundoplication (21.7 ± 1.5 cm H 2O) did not differ significantly from control values (24.3 $pL 1.8 cm H 2O), whereas significantly lower pressures were recorded after the Belsey Mark IV (11.7 ± 1.5 cm H 2O), Hill posterior gastropexy (9.0 ± 1.5 cm H 2O), and subdiaphragmatic transposition (4.0 ± 1.5 cm H 2O) procedures. The adaptive response of the lower esophageal sphincter to increased intragastric pressure was restored to near normal levels by both the Nissen and Belsey procedures, whereas the Hill posterior gastropexy and subdiaphragmatic transposition were less effective. In addition, pH reflux testing clearly indicated that the Nissen fundoplication afforded maximum protection against acid reflux. The experimental evidence suggests that optimum results in the surgical treatment of gastroesophageal reflux are achieved when the resting lower esophageal sphincter pressure and the adaptive response are restored to normal levels. The Nissen fundoplication accomplishes these objectives more effectively than the alternative antireflux procedures.