The histological appearances of Nissen-type fundoplication in the ferret

Postfundoplication retching: Strategies for management

BACKGROUND

Retching is a common symptom in children following antireflux surgery, particularly in those with neurodisability. There is now a strong body of evidence that implicates retching as a major cause of wrap breakdown. Retching is not a symptom of gastroesophageal reflux disease; it is a component of the emetic reflex. In addition to causing wrap breakdown, it is indicative of the presence of nausea. It is a highly aversive experience and warrants treatment in its own right.

METHODS

A framework was constructed for the management of postoperative retching, with strategies targeting different components of the emetic reflex. The impact of differing antireflux procedures upon retching was also considered.

CONCLUSIONS

Once treatable underlying causes have been excluded, the approach includes modifications to feeds and feeding regimens, antiemetics and motility agents. Neuromodulation and other, novel, therapies may prove beneficial in future. Children at risk of postoperative retching may be identified before any antireflux surgery is performed. Fundoplication is inappropriate in these children because it does not treat their symptoms, which are not because of gastroesophageal reflux, and may make them worse. They are also at risk of wrap disruption. Alternative strategies for symptom management should be employed, and fundoplication should be avoided.

LEVEL OF EVIDENCE

II-V.

Does retching matter? Reviewing the evidence-Physiology and forces

Failure of antireflux surgery is common in children with neurodisability, with a high incidence of persistent or recurrent symptoms, including retching. Anatomical disruption of the wrap is a frequent finding, but what forces underlie this disruption? This article reviews the forces generated during potential wrap-stressing episodes, putting them into the clinical context of wrap failure. Historically, wrap failure has been attributed to pressures arising from a reduction in gastric capacity or compliance, with advocates for an additional, gastric emptying procedure, at the time of fundoplication. However, any postoperative pressure changes are small and insufficient to cause disruption, and evidence of benefit from gastric emptying procedures is lacking. Diaphragmatic stressor events are common in the presence of neurodisability, and there is now increasing recognition of an association between diaphragmatic stressors and wrap breakdown. The analysis in this review demonstrates that the greatest forces on the fundoplication wrap are those associated with retching and vomiting. The direction and magnitude of these forces are sufficient to cause wrap herniation into the thorax, and wrap separation. Clinical series confirm that retching is consistently and strongly associated with wrap breakdown. Retching needs to be addressed if we are to reduce the incidence of wrap failure. Level of Evidence V.

Incorporation of Nissen fundoplication in a rat model of duodenoesophageal reflux

BACKGROUND

Few in vivo models of esophageal reflux and fundoplication suitable for the study of the pathogenesis of Barrett's esophagus and esophageal cancer exist. We describe a modification of a rat model of duodenoesophageal reflux that incorporates Nissen fundoplication and uses it to study the role of fundoplication in ameliorating esophageal reflux.

METHODS

A previously described rat model of duodenoesophageal reflux was modified to include Nissen fundoplication. Reflux threshold (RT), defined as the gastric pressure required to cause gastroesophageal reflux during transgastric instillation of saline, was measured in 12 Sprague-Dawley rats at baseline, after cardiomyotomy with esophagogastroduodenal anastomosis (EGDA), after subsequent Nissen fundoplication, and, finally, after takedown of Nissen fundoplication (NF).

RESULTS

Cardiomyotomy with EGDA induced no significant change in RT compared with baseline (mean RT +/- SD: 4.0 +/- 1.9 mmHg and 6.0 +/- 2.5 mmHg, respectively, p = 0.741). Nissen fundoplication led to a 14-fold increase in RT (56.4 +/- 18.2 mmHg) compared with cardiomyotomy. RT pressure reverted to baseline levels after NF takedown (4.7 +/- 2.9 mmHg, p < 0.001). Antegrade esophageal flow was demonstrated without an increase in distal esophageal pressure after NF.

CONCLUSIONS

Nissen fundoplication creates a one-way antireflux mechanism that eliminates gastroesophageal reflux in this rat model. This modification of an in vivo model of duodenoesophageal reflux represents a unique opportunity to investigate the effect of NF on cardiomyotomy-induced reflux and distal esophageal exposure to duodenogastric refluxate, and could be useful in the study of the role of NF in preventing progression to BE and ECA.

Gastrointestinal complications of fundoplication

In children with medically refractory gastroesophageal reflux disease (GERD), fundoplication is effective and safe. However, in a subset of patients, gastrointestinal dysfunction occurs postoperatively. Symptoms include chest pain, persistent dysphagia in 5%, gas bloat in 2% to 4%, diarrhea in up to 20%, and dumping syndrome in up to 30%. Symptoms are often nonspecific, arising from recurrent or persistent GERD, anatomic complications such as disrupted or herniated wrap, functional disturbances such as rapid gastric emptying or altered gastric accommodation, or alternative diagnoses such as cyclic vomiting syndrome or food allergy. Detailed investigation, including various combinations of pHmetry, videofluoroscopy, endoscopy, motility studies, and dumping provocation testing, may be required to clarify pathophysiology and guide management.