Thank you to Professor Giselle Hosgood BVSc (Hons), MS, PhD, FACVSc, Dipl. ACVS for your advice and assistance in creating this post. Gastroesophageal reflux in brachycephalic dogs is common and the pathophysiology is multifactorial. Underlying esophageal disease, upper airway obstruction leading to decreased intrathoracic/increased intraabdominal pressure, and oesophageal hiatal insufficiency have been proposed underlying factors. Some surgeons propose that correction of the underlying upper airway obstruction combined with medical management can reduce the occurrence of reflux; however, the underlying malformation of the hiatus, over time, may continue to allow regurgitation. "Circumferential esophageal hiatal rim reconstruction for treatment of persistent regurgitation in brachycephalic dogs: 29 cases (2016–2019)" Hosgood et al JAVMA 2021, discusses a technique for reconstructing the esophageal hiatal rim. In these dogs, there was marked laxity of the left and right pars lumbalis. This leads to lack of a 'pinchcock' effect from the crural muscles of the diaphragm (pinchcock = clamping off of a flexible tube). This paper has some really excellent diagrams (my favourite diagrams of the diaphragm). There is also a description of the technique.
"Circumferential esophageal hiatal rim reconstruction for treatment of persistent regurgitation in brachycephalic dogs: 29 cases (2016–2019)" Hosgood et al JAVMA 2021.
In this case series, post rim reconstruction and esophagopexy, regurgitation frequency was reduced. 7/29 dogs continued to have mild regurgitation that resolved with medical management (presumed esophagitis). In 16/19 dogs with long-term followup, regurgitation was resolved. Some of these dogs had airway surgery at the same time and my thought when reading this paper was whether the airway correction component may have contributed to the success. I was lucky enough to be able to discuss this with Professor Giselle Hosgood via personal communications. She made the point that most dogs have underlying hiatal malformation or laxity that contributes to regurgitation. Hiatal herniation, when identified, is likely an advanced change, often only noted in a small proportion of dogs. Because it represents a late change, and in essence an end point of hiatal malformation, it should not be the criteria that drives surgical reconstruction. In her experience, correcting the airways alone is insufficient to correct regurgitation. Often regurgitating dogs that have airway correction alone, will present in the future with worsened regurgitation. For this reason, she recommends correction of the hiatal malformation with rim reconstruction, as well as airway correction, in dogs with persistent regurgitation.