Prospective study of the effect of laparoscopic Nissen fundoplication on reflux mechanisms

Background: Laparoscopic Nissen fundoplication effectively reduces acid ref lux and reflux symptoms. Little is known about the effect on reflux mechani sms, especially on transient lower oesophageal sphincter relaxations (TLOSR s). Methods: Twenty-seven patients were studied prospectively before and after laparoscopic Nissen fundoplication, by simultaneous recording of pH and low er oesophageal sphincter (LOS) characteristics using sleeve manometry. In a ll of the 27 patients the operation was judged successful, based on major i mprovement or resolution of reflux symptoms and acid reflux. Vagus nerve in tegrity was studied indirectly by the secretion of pancreatic polypeptide ( PP) in response to insulin-induced hypoglycaemia. Results: After fundoplication basal LOS pressure increased significantly fr om mean(s.e.m.) 13(1) to 22(1) mmHg (P<0.001). Laparoscopic Nissen fundopli cation significantly decreased the frequency of TLOSR in the fasting period from mean(s.e.m.) 2.5(0.5) to 0.6(0.2) per h, and in the postprandial peri od from 4.0(0.4) to 1.3(0.3) per h (P<0.01). The percentage of TLOSRs assoc iated with reflux also decreased significantly from 24(10) to 0(0) per cent in the fasting period and from 42(6) to 12(6) per cent in the postprandial period, before and after fundoplication respectively (P<0.01). After opera tion the PP response was abnormal in three patients, pointing to vagus nerv e dysfunction. Postoperative TLOSR frequency and LOS pressure were no diffe rent between patients with and without vagus nerve dysfunction. Conclusion: Laparoscopic Nissen fundoplication significantly increased fast ing and postprandial LOS pressure and significantly decreased the rate of T LOSR. This resulted in a significant reduction in oesophageal acid exposure but postprandial LOS characteristics were preserved.