Unusual vascular ring anomaly associated with a persistent right aortic arch and an aberrant left subclavian artery in German pinschers

The objective of this study was to describe a specific form of persistent right aortic arch (PRAA) in three German pinscher dogs and to analyse the mode of inheritance in the breed. This type of PRAA is characterised by a left retro-oesophageal subclavian artery in combination with a ligamentum arteriosum originating at the aberrant left subclavian artery (PRAA-SA-LA). This rare combination of anomalies has only been reported in two isolated cases in other dog breeds and the occurrence of any form of PRAA was not previously known to occur in the German pinscher. In the present study, 18 cases of this congenital anomaly were ascertained and their high degree of relatedness and inbreeding could be shown through pedigree analysis. Three of the affected dogs underwent further clinical investigations, and post-mortem examination (two cases) and findings at surgery (one case) verified the diagnosis of PRAA-SA-LA. A monogenic autosomal recessive mode of inheritance was not likely.     

Surgical management of an aberrant left subclavian artery originating from a left patent ductus arteriosus in a dog with a right aortic arch and abnormal branching

An increase in the availability of advanced imaging modalities has led to improved recognition of cardiovascular anomalies. Computed tomography angiography (CTA) provides a non-invasive means of acquiring 3D images with a relatively short acquisition time thereby providing essential information in regards to patient anatomy and procedure planning. The dog in this report had a right aortic arch and abnormal branching with an aberrant left subclavian artery originating from the ampulla of a left patent ductus arteriosus (PDA) that was detected with CTA. The PDA was creating a volume overload to the left side of the heart as well as contributing to the vascular ring and compression of the esophagus. Therefore, ligation and transection instead of a minimally invasive catheter-based procedure was required. This aortic arch anomaly and surgical management have not been previously reported in dogs.     

Persistent right aortic arch and aberrant left subclavian artery in a white Bengal tiger (Panthera tigris).

A 3-mo-old male white Bengal tiger (Panthera tigris) presented with the chief complaint of regurgitation of solid food since weaning at 2 mo of age. Compared with its littermates, the tiger was in poor body condition and weighed only 10.3 kg when its littermates were estimated at 20-25 kg. Thoracic radiographs showed a megaesophagus cranial to the heart base. A contrast esophagram more clearly outlined the megaesophagus, and fluoroscopy demonstrated normal motility of the caudal esophagus. Endoscopic examination revealed a structure coursing dorsally from right to left over the esophagus and a constrictive band on the left of the esophagus at the heart base. Nonselective angiography confirmed the presence of a persistent right aortic arch, as well as an aberrant left subclavian artery. A left fourth intercostal thoracotomy was performed, and the ligamentum arteriosum was double ligated and divided. The left subclavian artery did not cause significant compromise of the esophagus and was not manipulated at surgery. The tiger recovered well from anesthesia and surgery. Solid food was slowly introduced over a 2-mo period without any regurgitation. The cub gained weight rapidly after surgery.     

Surgical correction of an aberrant right subclavian artery in a dog

A diagnosis of an aberrant right subclavian artery was made in a 3-month-old Boston terrier. Surgical correction was performed after confirming adequate collateral circulation. Reports of surgical correction and evaluation of the perioperative thoracic limb blood pressure are rare in dogs.     

Three cases of aberrant right subclavian artery in the dog

In the normal dog only 2 arteries leave the ascending aorta–the brachiocephalic trunk and the left subclavian artery. This communication describes 3 dogs, a labrador, a poodle and a german shepherd, in which 3 large arteries left the ascending aorta–firstly a trunk for both common carotid arteries, then a left subclavian artery and finally a right subclavian artery.     

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.     

Thoracoscopic correction of persistent right aortic arch in a dog.

A 15-week-old, male intact, miniature schnauzer presented for signs consistent with persistent right aortic arch (PRAA). Esophagram and esophagoscopy confirmed this diagnosis. Following selective intubation, the constricting ligamentum arteriosum was visualized and completely resected via thoracoscopy. No complications were noted with this procedure. Advantages of thoracoscopy for management of persistent right aortic arch observed in this case were better visualization of the ligamentum arteriosum, minor postoperative discomfort, and minimal intraoperative hypothermia. Therefore, thoracoscopy is a potential alternative to intercostal thoracotomy for correction of PRAA.     

Late-onset regurgitation associated with persistent right aortic arch in two dogs

Congenital persistent right aortic arch was diagnosed as the cause of weight loss and regurgitation in 2 dogs, aged 2.5 and 8 years, respectively. The first dog had 2 brief episodes of regurgitation that resolved spontaneously before the most recent onset of signs and diagnosis. The second dog had no clinical signs attributed to persistent right aortic arch until 2 months before the diagnosis was made. Dogs born with persistent right aortic arch typically have clinical signs of esophageal stenosis around the time of weaning. Evidence from the 2 dogs in this report indicate that clinical signs associated with vascular ring anomalies may not become evident until later in life. Veterinarians should consider the diagnosis of persistent right aortic arch in any age dog that is admitted because of regurgitation, weight loss, and dilatation of the cranial portion of the esophagus.     

Unusual vascular ring anomaly associated with a persistent right aortic arch in two dogs

An unusual vascular ring anomaly consisting of a persistent right aortic arch and a left ligamentum arteriosum extending from the main pulmonary artery to an aberrant left subclavian artery and left aortic arch remnant complex was identified in a German shepherd dog and a great Dane. The left subclavian artery and left aortic arch remnant complex originated at the junction between the right distal aortic arch and the descending aorta and coursed dorsal to the oesophagus in a cranial direction. The attachment of the ligamentum arteriosum to the aberrant left subclavian artery was approximately 5 cm cranial to the point of origin of the aberrant left subclavian artery and left aortic arch remnant complex from the descending aorta in both dogs. This anomaly observed in both dogs is similar to an anomaly reported in humans, in which a persistent right aortic arch is found in conjunction with an aberrant left subclavian artery and a left aortic arch remnant (Kommerell's diverticulum). Surgical ligation and division of the left ligamentum arteriosum in both dogs, along with division of the left subclavian artery in the great Dane, resulted in resolution of clinical signs in both of the dogs in this report.     

Thoracoscopic correction of a congenital persistent right aortic arch in a young cat

A 9-week-old kitten was diagnosed with a congenital vascular ring anomaly by means of an esophageal contrast study. At 6 mo of age, a non-selective vascular study was used to diagnose a persistent right aortic arch (PRAA). Left-sided thoracoscopic surgery was performed, using a Liga-Sure vessel sealant device to seal and transect the ligamentum arteriosum.     

Double aortic arch in a dog

Vascular ring anomalies are developmental anomalies of the thoracic great vessels resulting in complete or partial encircling of the esophagus and the trachea by a vascular ring formation. Persistent right aortic arch with left ligamentum arteriosum accounts for 95% of vascular ring anomalies in dogs. The dog in this report had a double aortic arch, which is a type 4 vascular ring anomaly. Double aortic arch is a rare congenital heart defect resulting from the improper development of the embryonic arches. The prognosis for dogs that have undergone surgery for correction of double aortic arches is generally regarded as poor. The dog in this report underwent surgery for correction of double aortic arches and recovered without dilation or motility disorders of the esophagus. Results indicate that small animals that undergo early surgical correction of double aortic arches with relief of esophageal constriction can have a good prognosis. To the authors' knowledge, there have been no previous reports of dogs that have survived long enough to be discharged from the hospital after surgical correction of double aortic arches.