Thoracoscopy with Concurrent Esophagoscopy for Persistent Right Aortic Arch in 9 Dogs

To report the diagnosis, treatment, and short-term outcome in dogs with suspected persistent right aortic arch (PRAA) undergoing thoracoscopy with concurrent esophagoscopy.

Multi-institutional retrospective case series.

Dogs with suspected PRAA (n=9).

Medical records were reviewed from 2012 to 2016. Dogs undergoing thoracoscopy for PRAA at 3 referral hospitals were included. Signalment, clinical signs, diagnostic imaging, anesthesia protocol (including the use of one-lung ventilation), surgical approach, complications, and short-term outcome were recorded. Dogs underwent a left-sided intercostal thoracoscopic approach with concurrent intraoperative esophagoscopy. The ligamentum arteriosum (LA) and constricting fibers were divided using a vessel-sealing device using a 3 or 4 port thoracoscopy technique. Visualization and dissection of the LA was aided by transesophageal illumination by esophagoscopy.

Thoracoscopy confirmed PRAA in 9 dogs, with an aberrant left subclavian artery (LS) identified in 5 dogs. Major complications occurred in 2 dogs: postoperative hemorrhage from the LS and esophageal perforation, which resulted in euthanasia. Median follow-up was 250 days (range, 56-1,595). Regurgitation resolved in 4 of 8 surviving dogs. One dog had recurrence of regurgitation 1,450 days postoperatively, esophageal compression by the LS was identified, and regurgitation resolved following LS transection.

Esophagoscopy aided identification and dissection of the LA in all cases. Due to the potential for the LS to cause clinical esophageal constriction postoperatively, a recommendation for LS transection may be warranted. Vascular clips can also be considered as an alternative for vessel ligation to avoid complications associated with vessel-sealing device use.