MANOMETRIC STUDY OF THE EFFECTS OF EXPERIMENTAL FUNDOPLICATION IN RATS

BACKGROUND: the manometric effects of surgical repair of gastroesophag eal reflux remain largely unknown, making the interpretation of the ch anges in the esophagogastric high pressure zone after fundoplication d ifficult. AIM: to measure in a murine model the transdiaphragmatic pre ssure gradients, intraabdominal esophageal length, and lower esophagea l sphincter pressure and length after Nissen fundoplication. MATERIAL AND METHODS: adult Wistar rats were divided into two groups Contro gro up (n = 10): in which measurements were made after laparotomy and intr aabdominal esophageal dissection. Nissen Group (n = 15): in which meas urements were made at baseline, after fundoplication and 1 week after surgery. We considered the following variables: end-inspiratory and en d-expiratory transdiaphragmatic gradient (TDIG and TDEG respectively), lower esophageal sphincter pressure (LESP) length (LESL), and length of the intraabdominal segment of the esophagus (LIAS). RESULTS: the LI AS increased significantly after esophagograstric dissection in the co ntrol group (11.38 +/- 3.22 mm vs 16.02 +/- mm, p < 0.05). No differen ces between pre-and postoperative status were found in TDIG, TDEG, LES P and LESL in the control group. However, LESP increased significantly after fundoplication (14.22 +/- 13.3 vs 32.96 +/- 7.8 mmHg, p < 0.05) and these differences were still present one week later (30.72 +/- 6. 73 mmHg, p < 0.05). LESL was also increased (1.91 +/- 1.76 mm vs 7.68 +/- 1.83 mm) after fundoplication (p < 0.05), and reached 7.02 +/- 2.1 8 mm (p < 0.05) 1 week later. No differences were found in pre-and pos toperative TDIG, TDEG and LIAS in the Nissen Group. CONCLUSION: in thi s murine experimental model, intraabdominal esophageal dissection incr eased the length of the intraabdominal esophagus without modifying the esophagogastric high pressure zone,while Nissen fundoplication increa sed lower esophageal sphincter pressure and length, without modifying the length of the intraabdominal esophagus or the transdiaphragmatic p ressure gradients.