Double aortic arch in a dog (Canis familiaris): a case report

Computed tomographic features of double aortic arch in six dogs

Double aortic arch (DAA) is a rare, congenital anomaly in small animals, resulting in a complete vascular ring encircling the esophagus and trachea, and subsequent compression of these organs. Few studies have reported utilizing CT angiography (CTA) for diagnosing DAA in dogs; thus, the imaging features are currently lacking in the literature. The objectives of this retrospective, multicenter, descriptive case series were to report the clinical and CTA characteristics of DAA in surgically treated cases. Medical records and CTA images were reviewed. Six juvenile dogs met the inclusion criteria (median age: 4.2 months; range: 2-5 months). The most common clinical signs included chronic regurgitation (100%), decreased body condition (67%), and coughing (50%). Common CTA features of DAA included a dominant left aortic arch (median diameter: 8.1 mm) and minor right aortic arch (median diameter: 4.3 mm; 83%), an aberrant right subclavian artery arising directly from the right aortic arch (83%), segmental esophageal constriction (100%), and variable degrees of dilation cranial to the heart base, and marked tracheal luminal compression (median percent change: -55%; 100%) and leftward curvature of the trachea at the level of the bifurcation of the aortic arches (100%). All dogs underwent successful surgical correction with only minor postoperative complications. Due to the similarity of clinical and imaging characteristics described to that of other forms of vascular ring anomalies (VRA), CTA is vital for the specific diagnosis of DAA in dogs.

Clinical findings, surgical treatment and long-term outcome of dogs and cats with double aortic arch: four cases (2005-2022)

OBJECTIVE

To describe the clinical presentation, diagnostic findings, treatment and long-term outcome following surgery of dogs and cats undergoing surgical treatment for a double aortic arch.

MATERIALS AND METHODS

Medical records of dogs and cats diagnosed with a double aortic arch between 2005 and 2022 at three small animal referral hospitals were retrospectively reviewed. Long-term outcome was assessed by a clinical examination and/or by contacting the owners or referring veterinarians.

RESULTS

Two dogs and two cats were included. Regurgitation after eating, stunted growth and poor weight gain were the predominant clinical features. All animals had thoracic radiography and oesophagography; a dilation of the cranial thoracic oesophagus cranial to the heart base, was described in all animals. CT angiography confirmed double aortic arch in three of these and the right aortic arch was larger and appeared more well developed compared with the left aortic arch in all based on CT or surgical findings. Surgery was performed via a left fourth intercostal thoracotomy; ligation and transection of the lesser left aortic arch was performed. Follow-up time ranged from 360 to 1563 days. All animals showed a marked improvement during the postoperative period, and all gained weight gradually. Owners' perception of the surgical procedure outcome and quality of life was described as excellent for all animals.

CLINICAL SIGNIFICANCE

Surgical ligation of the lesser aortic arch in dogs and cats with double aortic arch is associated with a favourable prognosis for recovery, resolution of clinical signs, and quality of life with only minor feeding modifications.

Anomalous branching of the aortic arch in a dog

Anomalies in the subclavian and common carotid arteries can be of interest in cases of cranial mediastinal surgeries, as well as to diagnose the cause of oesophageal constrictions leading to clinical signs of dysphagia (dysphagia lusoria). The development and regression of the aortic arches are of key importance in understanding the origin of these type of vascular anomalies. This report describes the congenital anomalous aortic origin of the common carotid and the subclavian arteries in a 14-year-old dog and the plausible developmental pattern failure. Academic dissection revealed a common bicarotid trunk and bisubclavian trunk arising from the most cranial aspect of the aortic arch. Despite the abnormal origin, these vessels displayed a predominantly standard anatomical course. All the anticipated branches were identified and described. Cardiac abnormalities were also noted including right atrial dilation, coronary sinus enlargement, right and left valvular endocardiosis, a patent foramen ovale and marked concentric left ventricular hypertrophy with compensatory left atrial dilation. Additionally, the right recurrent laryngeal nerve demonstrated an aberrant course consistent with a 'non-recurrent laryngeal nerve' (non-RLN). Awareness of the anatomical variations of the aortic arch is important for surgical interventions of the cranial mediastinum as well as radiological interpretation. Although infrequent, the variants similar to the one described here have been reported in different species.

Successful Surgical Therapy of a Double Aortic Arch in a 10-Month-Old Mixed Breed Dog

A 10-month-old female spayed mixed breed dog with a suspected vascular ring anomaly was presented for exercise intolerance and wheezing. Computed tomography (CT) revealed a double aortic arch. The smaller right aortic arch was successfully ligated via right 4th intercostal thoracotomy. The patient was discharged one day postoperatively and continued to have good outcome at recheck 3.5 weeks after surgery. This is the 4th documented case of double aortic arch with a successful outcome. Preoperative CT scan was vital in preoperative planning and should be strongly recommended in all cases of suspected vascular ring anomalies with atypical presentation.

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.

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.

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.