Hypoplastic aberrant left subclavian artery in a dog with a persistent right aortic arch

Vascular ring anomalies (VRA) are relatively uncommon cardiovascular disorders in canine patients. The most common VRA is a persistent right aortic arch (PRAA) with a left ligamentum arteriosum, however various other vascular anomalies resulting in tracheoesophageal compression have also been reported. We report a case of a dog with a PRAA and left ligamentum arteriosum with a hypoplastic aberrant left subclavian artery resulting in asymmetric cervicobrachial circulation. Selective angiography and ECG-gated multi-detector computed tomography were utilized in the evaluation of these defects. The case presented represents a unique vascular anomaly of the aortic arch not previously described in veterinary medicine.     

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.     

Unusual Combination of Multiple Vascular Anomalies in a German Shepherd Puppy with Megaoesophagus

A 2‐months‐old male German shepherd puppy was referred for regurgitation and delayed growth. Radiographic and endoscopic investigations revealed a precardiac megaoesophagus and oesophageal constriction at the level of the heart base. At post‐mortem examination, a specific form of persistent right aortic arch characterized by an aberrant left subclavian artery in combination with a ligamentum arteriosum originating at the aberrant left subclavian artery (PRAA‐SA‐LA) was detected. A complete‐type persistent left cranial vena cava (PLCVC) was also observed. This is the first report describing the association between PRAA‐SA‐LA and PLCVC in a dog with megaoesophagus.     

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.     

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.     

Non-selective computed tomography angiography of a vascular ring anomaly in a dog

Non-selective computed tomography angiography (CTA) is an emerging imaging technique that will have continued application in veterinary medicine because of its short scan time, use of a single, peripheral venous injection and availability of more detailed anatomic information—including 3-dimensional reconstructions. The improved anatomic detail may facilitate veterinary students' learning of complex aortic arch malformations and details relative to the surgical approach. Herein we describe application of its use in a dog with a vascular ring anomaly due to a persistent right fourth aortic arch and left ligamentum arteriosum. Additionally, we compare images with a normal dog.     

Vascular ring anomaly with coarctation of the aorta in a cat

A 13-week-old, entire male domestic shorthaired cat was presented with a nine-week history of regurgitation following the ingestion of food. A diagnosis of a vascular ring anomaly with coarctation of the aorta was based on clinical signs, angiography and echocardiography. Surgical exploration via a right lateral thoracotomy confirmed the existence of a persistent right aortic arch with right ligamentum arteriosum, aortic coarctation and an aberrant left subclavian artery. Following the surgical transection of the aberrant left subclavian artery, the cat made an uneventful recovery, showing normal swallowing function with no evidence of regurgitation. Twelve months after surgery, the cat had no special dietary requirements and remained clinically normal.     

Intra‐thoracic gossypiboma (textiloma) in a 6‐year‐old cocker spaniel

This report documents the first case of gossypiboma (textiloma) identified within the thorax of a dog. CT findings, surgical removal and histopathology are described. Intra‐thoracic gossypiboma has not previously been reported in dogs and is rarely reported in the human medical literature, where it is most commonly associated with previous cardiac or pulmonary surgery. This dog had previously had a thoracotomy for attempted surgical correction of a persistent right aortic arch and left ligamentum arteriosum 6 years prior to presentation. A brief review of the previous literature and recommendations for prevention of this condition are provided.     

Symmetrical double aortic arch in a beagle puppy

Double aortic arch denotes the persistence of both fourth aortic arches and has been reported as 'very rare' in the dog. Most reported cases have been seen in German shepherd dogs. An eight-week-old, male, 1.5-kg beagle presented with a three-week history of regurgitation and dyspnoea. A barium oesophagram showed severe oesophageal constriction cranial to the base of the heart, and a provisional diagnosis of a persistent right aortic arch was made. A left-sided fourth intercostal thoracotomy was performed. The ligamentum arteriosum was ligated and divided. The oesophagus was seen lying on the right-hand side of the aorta. Postoperatively, the puppy deteriorated and was euthanized. Postmortem revealed a double aortic arch entrapping both the oesophagus and trachea. The inexperienced surgeon could consider computed tomography or angiography to determine the exact vascular ring, and other possible concurrent vascular anomalies present, before surgery.     

Surgical treatment of a double aortic arch in a dog

An 8-month-old spayed female Labrador retriever dog was evaluated for regurgitation 6 months after surgery for a suspected vascular ring anomaly. The dog had a history of regurgitation and slow development as a puppy. An initial left-sided exploratory thoracotomy was unsuccessful in identifying and treating a vascular ring anomaly. The dog was subsequently presented to the PennVet Emergency Service for regurgitation. Thoracic radiography showed cranial thoracic esophageal dilation and an esophageal foreign body that was then removed endoscopically. Subsequent computed tomographic (CT) angiography revealed a double aortic arch. A left 4th intercostal space thoracotomy was performed. The smaller left aortic arch and a left ligamentum arteriosum were ligated and transected. The dog recovered uneventfully and was healthy at the 1-month follow-up visit. This is the 5th reported successful surgical correction of a double aortic arch in a dog. Computed tomographic angiography was essential in diagnosis and surgical planning.Key clinical message:Although uncommon, double aortic arches can occur and present a diagnostic and surgical challenge when a persistent right aortic arch is suspected. Computed tomographic angiography provides an accurate preoperative diagnosis and allows for surgical planning.     

Investigation of the potential heritability of persistent right aortic arch in Greyhounds

In 2 successive matings of the same dam and sire in a Greyhound kennel, 1 of 6 puppies and 2 of 6 puppies were born with persistent right aortic arch (PRAA) in the first and second litters, respectively. Many congenital heart defects in dogs are believed to be heritable; however, proof of this has been difficult to obtain. Genetic predisposition to PRAA has been reported in German Shepherd Dogs and Irish Setters. The occurrence of PRAA in related Greyhounds within a kennel suggested a genetic predisposition to PRAA in a breed with which it has not been associated previously. Although the number of matings available for analysis was insufficient to conclusively prove a genetic basis for these observations, the occurrence of PRAA in puppies arising from successive matings of the same dam and sire strongly suggests that some lines of dogs of various breeds may be genetically predisposed to PRAA.     

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.     

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.     

Necrosis and rupture of the aorta and pulmonary trunk in four horses

Four horses are described with rupture of the aortic arch and pulmonary trunk which resulted in a fistula between these vessels. Ruptures were located near the ligamentum arteriosum. Histological examination of the vessel walls revealed media necrosis which was probably due to intimal thickening and/or medial fibrosis of the vasa vasorum.     

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.     

Coarctatio aortae in pigs: a morphological approach

Two types of coarctatio aortae in pigs are described. In the juvenile type the, funnel-shaped, narrowing in the arcus aortae was located between the origin of the a. subclavia sinistra and the aortic end of the ductus arteriosus or ligamentum arteriosum. Until now, this type has been observed only in animals with other heart anomalies. In the adult type, the narrowing of the arcus aortae was crescent-shaped and was located at the aortic end of the ductus arteriosus or ligamentum arteriosum. Histologic examination of parts of the funnel-shaped and the crescent-shaped narrowing revealed that the two types of coarctatio aortae develop differently.     

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.     

Persistent right aortic arch in a yearling captive wood bison (Bison bison athabascae).

An undersized, 16-mo-old, captive wood bison (Bison bison athabascae) was observed with dysphagia and postprandial regurgitation. The animal died shortly after anesthesia was initiated for diagnostic purposes. At necropsy, a persistent right aortic arch and aberrant left subclavian artery were diagnosed. The vascular ring structure around the esophagus and the trachea caused a megaesophagus with complete esophageal obstipation and ulcerative esophagitis. The aberrant left subclavian artery did not significantly compromise the esophagus. Persistence of the right aortic arch is relatively rare in ruminants and has not previously been reported in a bison.