Ligation of the ligamentum arteriosum and aberrant left subclavian artery in five dogs in which persistent right aortic arch had been diagnosed

Objective To determine and report the diagnosis, treatment, and outcome in dogs with persistent right aortic arch (PRAA) with an aberrant left subclavian artery (ALS) that underwent thoracoscopic surgery. Animals Dogs with PRAA and an ALS (n = 5). Study design Short case series. Methods Medical records were reviewed from 2014 to 2019. Dogs that underwent thoracoscopy for PRAA with an ALS at an academic referral hospital were included. Signalment, clinical signs, diagnostic imaging, surgical approach, complications, and short‐ and long‐term outcomes were recorded. Results Persistent right aortic arch with an ALS was identified in five dogs. Dogs initially underwent a three‐port intercostal thoracoscopic approach, and an intercostal thoracotomy was performed in converted cases. In all five dogs, the ligamentum arteriosum (LA) and ALS were divided; three were performed by a thoracoscopy alone. Two cases were converted because of poor exposure (1) and requirement to temporary occlude an ALS (1). The ALS was ligated and divided in all dogs without apparent negative effects. No intraoperative or postoperative complications occurred. Four dogs had resolution of regurgitation, three of which required diet modification. One dog had reported regurgitation when it was excited. Median follow‐up was 188 days (range, 150‐1133). Conclusion Ligation and division of both the LA and the ALS in all dogs in this case series was safe and allowed for improvement in clinical signs and good to excellent long‐term outcomes. In addition, both thoracoscopy and thoracotomy were used safely and successfully for ligation and transection of the LA and ALS in all dogs.