Abstract from the AVMA Journal, sounds like PRAA surgery is very promising.

J Am Vet Med Assoc. June 1997;210(12):1761-3.
M M Muldoon1, S J Birchard, G W Ellison
1 Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Ohio State University, Columbus 43210, USA.

Abstract
OBJECTIVE: To evaluate long-term outcome of dogs with persistent right aortic arch that undergo surgical correction.

DESIGN: Retrospective study.

ANIMALS: 25 dogs.

PROCEDURE: Surgical correction consisted of ligation and division of the ligamentum arteriosum through a left fourth intercostal thoracotomy. Long-term (> 6 months after surgery) follow-up information was obtained by means of a telephone survey of owners (22 dogs) and by means of reevaluations by a veterinarian (3).

RESULTS: Median age at the time of surgical treatment was 12 weeks. Short-term (2 to 4 weeks after surgery) follow-up information was available for 14 dogs. Nine no longer regurgitated after eating, and 5 regurgitated infrequently. Follow-up esophagography (median time after surgery, 4 months) was performed in 13 dogs and revealed persistence of megaesophagus in all 13. At the time of long-term follow-up, 23 (92%) dogs no longer regurgitated after eating, and the remaining 2 (8%) had regurgitated less than once per week.

CLINICAL IMPLICATIONS: Contrary to previous reports, surgical correction of persistent right aortic arch resulted in complete alleviation of clinical signs in most dogs and an improvement in signs in the remaining dogs. Persistence of megaesophagus and regurgitation in the early postoperative period did not indicate a poor long-term outcome.