To compare the esophageal dynamic changes before and after laparoscopic Nissen fundoplication (LNF) in patients with gastroesophageal reflux disease (GERD) by high resolution manometry (HRM) and to explore the anti-reflux mechanism of the procedure.

A total of 73 consecutive hospitalized patients with GERD were included. A series of preoperative evaluations including HRM were performed within 1 weeks before LNF. After the GERD symptoms were significantly relieved and dysphagia and other complications disappeared, the HRM was rechecked. The 9 esophageal motility parameters of the HRM before and after operation were compared and analyzed, and further analysis was made on whether or not there were hiatus hernia before the operation.

The average length of esophagus was prolonged by (0.43±1.72) cm after operation, and the length of intra-abdominal and lower esophageal sphincter was prolonged by (1.20±0.94) cm. Postoperative resting pressure of the lower esophageal sphincter increased by an average of (5.99±7.79) mmHg and the integrated relaxation pressure increased by (3.41±5.43) mmHg. The distal contractile integral increased by an average of (157.26±596.01) mmHg?s?cm, the distal latency increased by an average of (0.93±2.30) s, the above 6 motility parameters compared with preoperative had significant difference (P=0.04, <0.01, <0.01, <0.01, 0.03, <0.01). There were no significant differences in the length of the lower esophageal sphincter, the pressure of the upper esophageal sphincter and the contractile front velocity after operation (P=0.83, 0.43, 0.73). The length of the esophagus, the length of the lower esophageal sphincter, and the distal contractile integral were significantly improved in the patients with hiatal hernia comparing with those without hiatal hernia (P<0.01, <0.01, <0.01).

The effective anti-reflux effect is mainly achieved by prolonging the length of the intraperitoneal esophageal, enhancing the lower esophageal sphincter pressure and enhancing the esophageal clearance function by LNF. Patients with esophageal hiatal hernia had better esophageal motility improvement than those without esophageal hiatal hernia.