Mechanical dilation, botulinum toxin A injection, and surgical myotomy with fundoplication for treatment of lower esophageal sphincter achalasia‐like syndrome in dogs

Abstract

Background Megaesophagus (ME) carries a poor long‐term prognosis in dogs. In people, lower esophageal sphincter (LES) achalasia is a rare cause of ME that may respond to targeted intervention. Dogs with lower esophageal sphincter achalasia‐like syndrome (LES‐AS) have been described recently, warranting investigation of analogous targeted treatment. Hypothesis/Objectives Evaluate response of dogs with LES‐AS to LES mechanical dilation and botulinum toxin A (BTA) injections, with or without surgical myotomy and fundoplication. We hypothesized that clinical and videofluoroscopic swallow study (VFSS) features of LES‐AS would improve after treatment targeting functional LES obstruction. Animals Fourteen client‐owned dogs with LES‐AS diagnosed by VFSS. Methods Retrospective study. Dogs diagnosed with LES‐AS underwent treatment between April 2015 and December 2017. Outcome measures included client perception of clinical severity, body weight (BW), body condition score (BCS), regurgitation frequency, and VFSS parameters (ME, esophageal motility, gastric filling). Dogs with positive responses were considered candidates for LES myotomy with fundoplication. Results By a median IQR of 21 (IQR, 14‐25) days after mechanical dilation and BTA, clients reported clinical improvement in 100% of dogs, BW increased 20.4% (IQR, 12.7%‐25%), pre‐ and post‐treatment BCS was 3 (IQR, 3‐4) and 5 (IQR, 4‐5), respectively, and frequency of regurgitation decreased by 80% (IQR, 50%‐85%). Duration of effect was 40 (IQR, 17‐53) days. Despite clinical improvement, ME and abnormal esophageal motility persisted in 14 dogs. Six dogs subsequently underwent myotomy and fundoplication and maintained improvement observed after mechanical dilation and BTA. Conclusions and Clinical Importance Dogs with LES‐AS experienced significant, temporary, clinical improvement after mechanical dilation and BTA. Preliminary results suggest myotomy with fundoplication provide lasting clinical benefit despite persistence of ME.

Use of a videofluoroscopic feeding evaluation to guide management of dogs with congenital idiopathic megaoesophagus

“…Retention of ingesta within the oesophagus was seen commonly in dogs within this study and is presumed to occur in many dogs with ME. This retention could be presumed to lead to the development of esophagitis, and oesophageal mucosal changes have been noted during endoscopy of dogs with ME (Grobman, Hutcheson, et al., 2019). For this reason, many owners of dogs in this study were advised to administer an oral proton pump inhibitor (omeprazole).…”

Evaluation of aerodigestive disease and diagnosis of sliding hiatal hernia in brachycephalic and nonbrachycephalic dogs

“…Importantly, AeroD may present in the absence of GI clinical signs (CS) and with normal thoracic radiographs making clinical recognition challenging 2 . Correction of the underlying AeroD has been demonstrated to improve clinical outcome, making identification of AeroD critical for optimal case management 6,9‐11 …”

“… 2 Correction of the underlying AeroD has been demonstrated to improve clinical outcome, making identification of AeroD critical for optimal case management. 6 , 9 , 10 , 11 …”

Reflux, aspiration and respiratory disease in dogs : clinical consideration and advances in aerodigestive diagnostics

“…This is especially important because our group later demonstrated that dogs with LES-AS, like people with LES-achalasia, respond to intervention directed at relieving the obstruction at the LES (Chapter 4). (313) In our study mechanical dilation and botulinum toxin A (BTA) injections at the LES resulted in 100% perceived clinical improvement by owners as well as significantly increased body weight, body condition score, and significantly reduced regurgitant frequency. (313) These subjective and objective clinical assessments were supported by improved swallowing parameters as detected by VFSS.…”

“…A Heller myotomy with Dor fundoplication was found to be similarly effective and may represent a long-term intervention in dogs with LES-AS. (313) The findings of this study provide hope for a population of dogs with a disease for which there have been historically very few therapeutic options.…”