Mechanisms underlying the antireflux action of fundoplication.

Abstract

The effect offundoplication on patterns of gastrooesophageal reflux and the underlying motor mechanisms were investigated in 18 patients with symptomatic reflux. Oesophageal motility and pH were recorded concurrently after a standard meal. Studies were performed preoperativey and from 5 to 27 months after surgery. Fundoplication virtually eliminated reflux in all but three patients. Control of reflux was associated with a 50% fall in the number of transient lower oesophageal sphincter relaxations, a fall in the proportion oftransient lower oesophageal sphincter relaxations accompanied by reflux from 47% to 17%, and an increase in the mean residual pressure at the gastro-oesophageal junction during swallow induced lower oesophageal sphincter relaxation from 0-7 mm Hg to 6*0 mm Hg. Basal pressure at the gastro-oesophageal junction rose from 10-9 mm Hg to 14*5 mm Hg, however, there was no correlation between postoperative reflux and basal gastro-oesophageal junction pressure. These findings suggest that the antireflux effects of fundoplication result from changes in the mechanical behaviour of the gastro-oesophageal junction that result in inGastroenterology Unit, complete abolition of the high pressure zone Royal Adelaide Hospital during lower oesophageal sphincter relaxation, A C Ireland and reduced triggering of transient lower R H Holloway oesophageal sphincter relaxations.

Review article: the clinical relevance of transient lower oesophageal sphincter relaxations in gastro-oesophageal reflux disease

“…84,96 The third mechanism by which anti-reflux surgery (complete and partial fundoplication) causes a reduction in reflux episodes is a decreased rate of TLOSRs. [97][98][99][100] Furthermore, the percentage of TLOSRs associated with reflux was found to be decreased after fundoplication. 97,98 The mechanism by which a fundoplication results in a decreased rate of TLOSR is unclear.…”

“…[97][98][99][100] Furthermore, the percentage of TLOSRs associated with reflux was found to be decreased after fundoplication. 97,98 The mechanism by which a fundoplication results in a decreased rate of TLOSR is unclear. Fundoplication reduces the volume of the proximal stomach, theoretically leading to a decrease in gastric distensibility and a decreased gastric receptor activation.…”

The Spectrum of Motor Function Abnormalities in Gastroesophageal Reflux Disease and Barrett’s Esophagus

“…Studies assessing the effects of healing of esophagitis on esophageal motility have yielded inconsistent results. Improvement in esophageal contractility and LES pressure has been occasionally reported with acid suppressive therapy [56,57,58] and also from surgical series [59,60,61]. An increase in the amplitude of esophageal contractions and a corresponding decrease in the number of ineffective swallows was documented on manometry in patients after a median follow-up of 3.5 years after Nissen fundoplication [59].…”

“…Sagar et al [60] reported a significant improvement in LES pressure after fundoplication, with 24 of 56 patients showing partial or complete regression of Barrett’s esophagus. Ireland et al [61] reported two major effects of fundoplication: a 50% reduction in the rate of TLESRs and a reduction in the proportion of TLESRs that were accompanied by reflux from 46 to 17%. Nevertheless, such improvement in LES pressure may simply represent the effects of the artificial high-pressure zone that was created around the LES by fundoplication, and which persists during both transient and swallow-induced LES relaxation [62].…”

Approaches to driving the evolving understanding of lower oesophageal sphincter mechanical function

“…First sleeve sensor and then HRM studies have shown that antireflux surgery causes a minor impairment of the completeness of the swallow-induced reduction of gastro-oesophageal junction pressure (Ireland et al, 1993;Clouse et al, 2000) and that persistent, troublesome post-surgical dysphagia can be related to excessive impairment of this swallow relaxation response (Ireland et al, 1993;Scheffer et al, 2005). HRM also has the potential to be able to determine whether dysphagia is related to a too tight fundic wrap or a constrictive diaphragmatic hiatus (Kahrilas et al, 2000).…”