Short- and long-term outcome of dogs following surgical correction of a persistent right aortic arch.

This study reports the survival to discharge, postdischarge survival, and long-term outcome of dogs following surgical correction of a persistent right aortic arch (PRAA). Information for 52 dogs, 28 dogs, and 23 dogs was available for analysis of survival to discharge, postdischarge survival, and long-term outcome, respectively. Ninety-two percent of dogs survived to the time of discharge and 18% of dogs surviving to discharge were euthanized within 2 mo of surgery. Breed, age at the time of presentation, and gender were not correlated with increased odds of death prior to discharge from the hospital. Long-term outcome for dogs was excellent in 30%, good in 57%, and poor in 13% of dogs. Although this study shows a relatively high mortality rate prior to discharge from the hospital and within 2 mo of surgical treatment, the long-term outcome is good or excellent in 87% of survivors. Dogs frequently display either residual clinical signs or require dietary modification long-term, but owner satisfaction is high.

Spontaneous resolution of postoperative chylothorax following surgery for persistent right aortic arch in two dogs.

Two young dogs underwent surgical management of a persistent right aortic arch (PRAA) and developed chylothorax postoperatively. In both cases, the surgical procedure and anesthetic recovery were uncomplicated and routine. Following surgery, both patients appeared bright, alert, responsive, and previous signs of regurgitation had resolved. Dyspnea and tachypnea developed 1-2 days postoperatively in each patient, and chylous effusion was detected on thoracocentesis. For each case, a diagnosis of chylothorax was based on cytology and triglyceride concentrations of the aspirated pleural fluid. Similar protocols for monitoring were used in the treatment of each patient's chylothorax. The duration and volume of chylous effusion production were closely monitored via routine thoracostomy tube aspiration. Both dogs rapidly progressed to recovery with no additional complications. With diligent monitoring, chylothorax secondary to surgical trauma can resolve in a rapid, uncomplicated manner.

Delayed primary surgical treatment in a dog with a persistent right aortic arch.

A 5-year-old, 1.36-kg, neutered male Yorkshire terrier was referred for evaluation of a persistent right aortic arch with concurrent megaesophagus. The dog was 3 months old when clinical signs were first noted, 2 years of age when diagnosed with megaesophagus, and 4 years of age when diagnosed with vascular ring anomaly (VRA). Surgical correction of the VRA was performed when the dog was 5 years of age, after gastrostomy tube feeding for 1 year to maintain nutritional requirements and mitigate the degree and duration of the esophageal distention. Thirteen months after surgery, the dog was eating soft dog food with no vomiting or regurgitation.

Multiple vascular anomalies in a regurgitating German shepherd puppy.

Five cardio-thoracic vascular anomalies were detected in a German shepherd puppy. The patent ductus arteriosus (PDA) was detected on physical examination (5/6 continuous murmur) and confirmed by echocardiogram. The persistent right aortic arch (PRAA) was suspected by the signalment and history of the patient, and confirmed by survey thoracic radiographs (leftward deviation of the trachea cranial to the heart on the ventrodorsal projection). The ventrally deviated trachea cranial to the heart on the right lateral thoracic radiograph was suggestive of a persistent retroesophageal left subclavian artery and confirmed at surgery. The persistent left cranial vena cava and the left azygous vein were detected at surgery. This case report gives a thorough description of the clinical signs, diagnostics and treatments required for the detection and successful resolution of PRAA. The report describes the importance of having experienced surgeons who can recognize vascular anomalies associated with PRAA in order to successfully alleviate the arch and the coinciding oesophageal stricture without compromising vital blood supplies.

Tracheal signs and associated vascular anomalies in dogs with persistent right aortic arch.

Medical records of 55 dogs with 1 or more vascular rings around the esophagus and trachea were reviewed to determine the nature and frequency of related vascular anomalies and to determine the reliability of tracheal deviation on radiographs for the diagnosis of persistent right aortic arch (PRAA). Fifty-two (95%) of the 55 dogs had PRAA. Of the 52 dogs with PRAA, 44% had coexisting compressive arterial anomalies: 17 had retroesophageal left subclavian artery and 6 had double aortic arch with atretic left arch. Characteristic tracheal deviation was consistently present in dogs with PRAA. Moderate or marked focal leftward curvature of the trachea near the cranial border of the heart in dorsoventral (DV) or ventrodorsal (VD) radiographs was found in 100% of available radiographs of 27 dogs with PRAA. Moderate or marked focal narrowing of the trachea also was noted in 74% of DV or VD radiographs and 29% of lateral radiographs of the dogs. Tracheal position in 30 of 30 dogs with megaesophagus and 62 of 63 control dogs was midline or rightward in VD or DV radiographs. Histology in a neonatal dog with PRAA revealed evidence of tracheal deviation and compression even before birth. Focal leftward deviation of the trachea near the cranial border of the heart in DV or VD radiographs is a reliable sign of PRAA in young dogs that regurgitate after eating solid food, and contrast esophagrams are not necessary to confirm the diagnosis of vascular ring compression.

Unusual vascular ring anomaly in a foal.

A 2.5-month-old filly was presented with signs of esophageal obstruction. The filly was euthanized and postmortem examination revealed a vascular ring anomaly. The vascular ring anomaly was not caused by a persistent right aortic arch, which is the only vascular ring anomaly reported to occur in horses.

Video-assisted thoracoscopic division of the ligamentum arteriosum in two dogs with persistent right aortic arch.

Video-assisted division of the ligamentum arteriosum can be performed successfully in dogs with minimal postoperative complications and hospitalization time. Single-lung ventilation and thoracic insufflation are not mandatory and standard instrumentation may be used for most of the procedure.

Long-term results of surgical correction of persistent right aortic arch in dogs: 25 cases (1980-1995).

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.