Persistent Right Aortic Arch (PRAA) is one of the most frequent congenital vascular system anomalies in dogs, responsible for the formation of a vascular ring that compresses the esophagus and can lead to the development of megaesophagus and recurrent regurgitation, especially during the post-weaning period. Given the clinical relevance of this condition and its potential complications, this study aims to report the anesthetic and surgical management of a PRAA case in a pediatric patient, highlighting the necessary care to minimize perioperative risks. The methodology consists of a case report from the Veterinary Hospital of the Federal Rural University of Pernambuco (UFRPE), involving a four-month-old mixed-breed female dog referred for surgical correction of the anomaly. Preoperative laboratory tests and clinical evaluation were performed, followed by a balanced anesthetic protocol using methadone and midazolam as pre-anesthetic medication, induction with propofol, and maintenance with inhalation anesthesia associated with a constant rate infusion (CRI) of remifentanil and lidocaine. Ultrasound-guided intercostal and serratus plane blocks were performed with bupivacaine and ropivacaine, respectively, along with continuous monitoring throughout the procedure. The intervention lasted approximately two hours and proceeded without relevant anesthetic complications, maintaining cardiovascular and ventilatory stability. In the immediate postoperative period, the patient showed satisfactory recovery with no episodes of regurgitation. It is concluded that the application of multimodal anesthesia, combined with intensive monitoring and adequate airway protection, significantly contributes to the safety and success of perioperative management in patients with PRAA.

A 4-month-old intact male Sapsaree dog was referred due to a history of postprandial regurgitation following consumption of solid food. Thoracic radiography revealed focal leftward displacement of the thoracic trachea at T1 to T4 vertebrae levels. Barium contrast radiography revealed focal dilation of the cranial thoracic esophagus at the heart base level. Persistent right aortic arch (PRAA) with an aberrant left subclavian artery branching from the patent ductus arteriosus was diagnosed by computed tomography angiography (CTA). Although barium contrast radiography can presumptive diagnose PRAA, CTA should be considered for identifying additional vascular anomalies, specific types, and surgical planning.

A 1.5-year-old male German Shepherd dog was referred to a Teaching Veterinary Hospital with a chronic history of regurgitation and a previous presumptive diagnosis of megaesophagus. An esophagogram showed partial esophageal dilation, suggesting one vascular ring anomaly. Computed tomography identified a persistent right aortic arch (PRAA) and an aberrant left subclavian artery (ALSA). The patient underwent thoracotomy, ligamentum arteriosum ligation, and debridement of the periesophageal region. The ligation of the ALSA was not carried out because the esophagus was observed to be released entirely during the surgical intervention. Therefore, intervention on the subclavian artery was not necessary. Clinical follow-up occurred on seven, 14, and 30 postoperative days. The dog improved, showing only sporadic regurgitations. Clinical history and complementary exams were essential to establish a diagnosis. The liberation of the esophageal transit during surgery contributed to the decision not to perform the ALSA ligation.

Aortic arch anomalies can give rise to vascular rings, such as persistent right aortic arch (PRAA), a rare vascular anomaly in cats with significant health implications. Here, we report late surgical correction in a case of PRAA, an almost 12-month-old cat with the clinical syndrome of dysphagia and postprandial regurgitation. The patient was presented to the veterinary hospital at FMVZ-USP with a history of chronic regurgitation since puppyhood after weaning, with a significant worsening of the clinical condition 10 days ago. Computed tomography had a potential role in diagnosing and detecting complications of PRAA, allowing surgical planning. Approach via left thoracotomy and section of the arteriosus ligament resulted in the successful resolution of extrinsic esophageal compression due to PRAA with the restoration of normal swallowing of a dry diet by the cat and absence of esophageal sequelae on radiographic assessment in a six-month clinical follow-up.

SummaryCongenital vascular ring anomalies (VRA) have been occasionally described in horses. To the authors' knowledge, this is the first case report providing radiographic and computed tomography (CT) findings of a congenital type 3 persistent right aortic arch (PRAA) in a foal. A 1.5 months old Franches‐Montagnes colt was presented for growth retardation with a history of mild intermittent bilateral nasal discharge occasionally containing milk and coughing since birth. Thoracic radiographs and ultrasound, oesophagoscopy, positive contrast oesophagography and CT angiography were performed. A final diagnosis of persistent right fourth aortic arch, with left ligamentum arteriosum and aberrant left subclavian artery (type 3 VRA) and subsequent aspiration pneumonia was achieved. Due to the poor physical condition, the presence of severe aspiration pneumonia and most importantly the lack of a surgical option for a type 3 VRA, the colt was euthanised and the post‐mortem examination confirmed the oesophagography and CT angiography findings.

To evaluate thoracoscopic treatment of persistent right aortic arch (PRAA) in dogs with and without the use of one lung ventilation (OLV). Retrospective cohort study. Twenty-two (client-owned and shelter) dogs diagnosed with PRAA. Medical records were reviewed retrospectively and intraoperative and immediate postoperative data were compared between dogs that underwent thoracoscopic treatment of PRAA with (OLV+) and without (OLV-) OLV. Ten of the 12 dogs in the OLV+ group and 7/10 dogs in the OLV- group had their left ligamentum arteriosum successfully ligated during thoracoscopy. Median surgical time, surgery complications, anesthesia complications, and rate of conversion to an open thoracotomy due to limited visualization or surgical complications were similar between the two groups. Thoracoscopic treatment of PRAA can be performed with or without OLV. Surgical time, intraoperative complications, and conversion rates were similar between dogs that underwent thoracoscopic treatment of PRAA with and without OLV. OLV may not have contributed to improved visualization in this group of dogs. The use of OLV is safe during thoracoscopic treatment of PRAA. OLV did not appear to provide significant benefits in this case series and thoracoscopic treatment of PRAA in dogs may be performed successfully with or without the use of OLV.

BackgroundCongenital heart diseases are occasionally encountered in the bovine species. Ventricular septal defects (VSD) and atrial septal defects (ASD) are reported to be the most common; however, a vast collection have been reported [1, 2]. Congenital heart diseases is thought to represent less than 3% of all congenital abnormalities in calves [3]. Various cardiac anomalies arise due to defective embryologic development such as defects of the septae or the cardiac chambers [2]. The exact aetiology of these congenial heart anomalies remains to be fully elucidated [4]. VSDs appear to be the most common congenital cardiac anomaly in calves. Other diseases can be subdivided into cyanotic (e.g. ASD or patent ductus arteriosus) and non-cyanotic (e.g. tetralogy of fallot or eisenmengers complex) [5, 6]. An exceptional presentation of an array of congenital anomalies was identified in a Friesian heifer calf. To the authors’ knowledge this concurrent collection of congenital abnormalities has never been reported in this species.Case presentationA 3-day old Friesian heifer presented with a history since birth of regurgitation post feeding. The main finding on clinical examination was tachypnoea with a holosystolic murmur. Echocardiography identified a VSD, patent foramen ovale (PFO) (both with left to right blood flow) and tricuspid insufficiency. The calf was subsequently euthanised and underwent gross post-mortem examination. A persistent right aortic arch (PRAA) was identified. The cardiac anomalies identified on the echocardiogram were confirmed along with additional abnormalities; double outlet right ventricle (DORV), partial transposition of the great vessels, pulmonic stenosis, hypoplasia of the right branch of the pulmonary artery and right ventricular hypertrophy. The final diagnosis was Tetralogy of Fallot with DORV, PFO and PRAA. The lungs appeared oedematous and congested due to cardiac malfunction and cranioventral aspiration pneumonia. Free serous fluid was identified in the thoracic cavity. Unilateral renal agenesis of the left kidney was an incidental finding but is of note due to its coexistence with the cardiac abnormalities.ConclusionsThis is an unusual case as it features numerous congenital abnormalities that appeared to negate each other allowing capability with life. To the authors’ knowledge, this collection of concurrent cardiac anomalies has not been previously reported in bovines.

Vascular ring anomalies present in young patients and will inhibit growth and development. Therefore it is essential that these patients have the anomaly corrected as soon as clinically stable enough to undergo surgical correction. In particular the congenital malformation of the persistent right aortic arch (PRAA) is uncommon in practice to see, but does require good knowledge and understanding by the veterinary team to provide a successful outcome.

OBJECTIVE To evaluate thoracoscopy as a treatment for dogs with persistent right aortic arch (PRAA) and to compare intra- and postoperative complications and short-term outcomes of dogs that underwent thoracoscopy versus thoracotomy for treatment of PRAA. DESIGN Retrospective cohort study. ANIMALS 30 dogs (24 client-owned and 6 shelter-owned) that had undergone thoracoscopy or thoracotomy for treatment of PPRA between 1998 and 2015. PROCEDURES Medical records were reviewed retrospectively, and data were compared between dogs that underwent thoracoscopy versus thoracotomy. For dogs that underwent thoracoscopy, linear regression was performed to compare duration of surgery with sequential order of thoracoscopies. RESULTS Dogs underwent a thoracotomy alone (n = 15), thoracoscopy alone (10), or thoracoscopy converted to thoracotomy (5) for treatment of PRAA. Median duration of surgery was not markedly different among groups, nor was the incidence of postoperative complications or median amount of time a thoracostomy tube was maintained in place. Median duration of hospitalization was 1 day (range, 0.5 to 2 days) for dogs that underwent thoracoscopy and 2 days (range, 0.5 to 22 days) for dogs that underwent thoracotomy or in which thoracoscopy was converted to a thoracotomy. CONCLUSIONS AND CLINICAL RELEVANCE Thoracoscopy was found to be an acceptable method for treating dogs with PRAA and was not associated with higher morbidity or mortality rates, compared with thoracotomy.

Background: : : Vascular ring anomalies were congenital malformation of the great vessels, caused by defects in embryogenesis of the aortic arches. In dogs the most common type is persistent right aortic arch (PRAA). The PRAA occurs when the fourth right aortic arch persists instead of left to form the aorta. This malformation causes extraluminal compression of the esophagus up to the base of the heart. The constriction leads to esophageal dilatation secondary, located cranial to the base heart. The food, which can not progress beyond the narrowing, is regurgitated intermittently. Thus, the main clinical sign of disease is regurgitation when the patient starts eating solid foods. Respiratory clinical signs (mainly pneumonia by aspiration) may occur and can complicate the disease. The diagnosis is suspected by history (puppies at weaning) and physical examination. The diagnosis is confirmed by the esophagogram, where the image is characteristic (esophagic dilatation cranial base of the heart). The treatment of the affection is surgical, with transection and ligature of the vascular ring, viewed during thoracotomy by fourth intercostal space. The postoperative management which consists mainly of liquid diet and/or pasty is important for total recovery of the animal. In some cases, the animal must receive a special diet for life to prevent regurgitation. However at long term, most operated animal presents important sequels. These sequelae include respiratory disorders and low development of animal. The objective of the present paper is to relate a case of bitch with persistent right aortic arch, successful treated surgically, without serious clinical consequences. Case: A mongrel bitch with 2 months of age was attended at the Veterinary Hospital of the Federal University of the Piauí, Brazil, with vomiting. At the clinical examination was observed increase in volume in the cervical region. Radiographic examination revealed dilatation cranial to the heart base, characterizing megaesohagus. The diagnosis was PRAA. The dog was submitted at thoracotomy by fourth right intercostal space. The ligamentum arteriosum was localized and ligated at the distal and craniallly. During transoperative was made blood transfusion for correction of the anemia detected in preoperative period. The chest wall was closed routinely. Two days after surgery the dog was discharged. The postoperative diet consisted of liquids for a week, followed by semi-solid food always in bipedal position. After discharge, the owner returned for monthly visits for a year, with completion of physical examination and radiographs. Discussion: PRAA is most common in purebred dog, but in this case the animal is a mixed breed dog. The diagnosis was suspected due to history, and confirmed by esophagogram, where there was megaesophagus cranial to the heart base, according by literature. The surgical treatment, rapidly decided, and the absence of pneumonia, which is the main complication postsurgical, contributed to the observed good results. The blood transfusion to correct anemia also was important for the recovery of the animal. There is an esophageal dilatation after one year, however no clinical manifestation occurs. The dog has a normal life. Excellent results as in the case reported here have a slower rate than 10%.

To report the diagnosis, treatment, and short-term outcome in dogs with suspected persistent right aortic arch (PRAA) undergoing thoracoscopy with concurrent esophagoscopy. Multi-institutional retrospective case series. Dogs with suspected PRAA (n=9). Medical records were reviewed from 2012 to 2016. Dogs undergoing thoracoscopy for PRAA at 3 referral hospitals were included. Signalment, clinical signs, diagnostic imaging, anesthesia protocol (including the use of one-lung ventilation), surgical approach, complications, and short-term outcome were recorded. Dogs underwent a left-sided intercostal thoracoscopic approach with concurrent intraoperative esophagoscopy. The ligamentum arteriosum (LA) and constricting fibers were divided using a vessel-sealing device using a 3 or 4 port thoracoscopy technique. Visualization and dissection of the LA was aided by transesophageal illumination by esophagoscopy. Thoracoscopy confirmed PRAA in 9 dogs, with an aberrant left subclavian artery (LS) identified in 5 dogs. Major complications occurred in 2 dogs: postoperative hemorrhage from the LS and esophageal perforation, which resulted in euthanasia. Median follow-up was 250 days (range, 56-1,595). Regurgitation resolved in 4 of 8 surviving dogs. One dog had recurrence of regurgitation 1,450 days postoperatively, esophageal compression by the LS was identified, and regurgitation resolved following LS transection. Esophagoscopy aided identification and dissection of the LA in all cases. Due to the potential for the LS to cause clinical esophageal constriction postoperatively, a recommendation for LS transection may be warranted. Vascular clips can also be considered as an alternative for vessel ligation to avoid complications associated with vessel-sealing device use.

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.

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.

Persistent right aortic arch (PRAA) in cats is an uncommon vascular anomaly with clinical signs referable to oesophageal obstruction. To our knowledge no reports of axial skeletal malformations concomitant to PRAA have been reported in cats. The aim of this study is to depict a new clinical feature in cats affected by PRAA. In the study six cats with a diagnosis of vascular ring anomaly were enrolled. A complete physical examination, a neurological examination and a total body radiograph were performed on each animal. Four of the six cats showed contemporary PRAA and skeletal malformations. Additionally, for the first time, a genetic test was performed on one subject to detect DNA alterations in the homologous DiGeorge region of cat. The percentage of skeletal malformations reported in the normal population was compared with animals with PRAA and showed a higher frequency. Genetic testing failed to demonstrate a correlation between PRAA and DiGeorge genomic deletion. A review of veterinary and human diseases that presented both conditions was assessed. The few animals enrolled do not allow definitive conclusions. Further studies are required to corroborate the correlation between PRAA and axial skeletal malformations in cats.

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

A 4-month-old female mixed breed dog was presented to the University of Tennessee College of Veterinary Medicine with a history of regurgitation and cachexia. Thoracic radiographs revealed focal megaesophagus cranial to the heart base. Magnetic resonance imaging (MRI) was performed. True fast imaging with steady-state precession (TrueFISP), fast low angle shot (FLASH), and short tau inversion recovery (STIR) sequences were acquired prior to contrast medium administration. Contrast-enhanced magnetic resonance angiography (CE-MRA) demonstrated focal megaesophagus and position of the aortic arch to the right of the esophagus. A small ductus diverticulum and an indistinct linear soft tissue band crossing the esophagus were also noted. Surgical exploration confirmed MR diagnosis of a persistent right aortic arch (PRAA) with left ligamentum arteriosum. The dog improved following surgery but was unable to be transitioned to dry food. To our knowledge this is the first report describing the use of CE-MRA for preoperative diagnosis and guided surgical treatment of a vascular ring anomaly in a dog.

Persistent right aortic arch (PRAA) is a congenital vascular ring anomaly common in several dog breeds. In German Pinscher, the disorder is characterized by a left retroesophageal subclavian artery in combination with a ligamentum arteriosum originating at the aberrant left subclavian artery (PRAA-SA-LA). In this study, we genotyped 38 microsatellite markers on canine chromosome 26 (CFA26) in German Pinschers and tested them for linkage and association. We found a chromosome-wide significantly linked genomic region on CFA26, which corresponds to the human DiGeorge syndrome critical region (DGCR). Therefore, we analyzed sequences from 13 genes of DGCR and the canine t-box gene TBX1. We identified a total of 26 polymorphisms in German Pinschers. Three of these SNPs located within TBX1 and one in the mitochondrial ribosomal protein L40 gene (MRPL40) were associated with the PRAA-SA-LA phenotype in German Pinscher. Despite linkage and association between PRAA-SA-LA and the canine DGCR, none of these mutations appeared responsible for PRAA-SA-LA. As the orthologue human region on HSA22q11.2 is known for high susceptibility to genomic rearrangements, we suspect that in German Pinschers, chromosomal aberrations might cause PRAA-SA-LA.

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

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.

A 10-week-old, 4.5 kg female Weimaraner dog was referred to theChonbukNationalUniversity, Animal Medical Centre with signs of regurgitation after weaning. The cervical oesophagus was palpable as a flaccid, air-filled cavity. The thoracic radiographs revealed oesophageal dilatation cranial to the heart and constriction at the level of third rib. A presumptive diagnosis was made as persistent right aortic arch (PRAA). A left 4th intercostal thoracotomy was performed and the definitive diagnosis was made as PRAA with left ligamentum arteriosum (LA) and an aberrant left subclavian artery (SA). The oesophagus was found dually compressed and severely necrosed. The corrective surgery comprised of transection of the LA as well as resection and anastomosis of the oesophagus, which resulted in a complete alleviation of the clinical signs.