Standing myotomy to treat fibrotic myopathy: 22 cases (2004-2016).

OBJECTIVE: To report the clinical and diagnostic findings associated with fibrotic myopathy, describe the surgical procedure for standing fibrotic myotomy and report postoperative outcomes. STUDY DESIGN: Retrospective study. SAMPLE POPULATION: Twenty-two horses. METHODS: Records were included if a clinical diagnosis of fibrotic myopathy was based on clinical and/or ultrasonographic examination and the horse was treated with myotomy of the affected muscle. Records were reviewed for signalment, preoperative findings, perioperative complications, and outcomes. Follow-up also included a phone survey of owners. RESULTS: Quarter horses represented 14 of 22 horses in this study. Ultrasonographic examination was performed in 14 of 22 horses. The semitendinosus muscle was affected in 17 of 22 horses. Other muscles affected included the semimembranosus, gracilis, and biceps femoris. Four of the 22 horses had a diagnosis of incisional postoperative complications. Eight of 12 formerly athletic horses returned to their intended athletic use. Ten of 16 owners were satisfied with the procedure. CONCLUSION: Prognosis for long-term comfort after standing fibrotic myotomy was fair with appropriate rehabilitation. Ultrasonographic examination was helpful in identifying the muscles affected and aided in surgical planning. CLINICAL IMPACT: Standing fibrotic myotomy is a technically straightforward procedure that yields a fair outcome in horses with minimal intraoperative and/or postoperative complications.

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

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.