Patent ductus arteriosus in a dog: modified method of double ligation]

Patent ductus arteriosus, a common congenital cardio-vascular disease, needs surgery for correction. Three methods are described: 1. transsection and suturing of the ductus ends; 2. dissection of the ductus itself and occlusion by double ligation (classical method), 3. modified double ligation described by Jackson and Henderson. A modification of the technique is described, based on the previous methods of double ligation.     

Patent ductus arteriosus in Murrah buffalos

Two cases of patent ductus arteriosus are described in 2 Murrah buffalos, a 7.5-month-old heifer calf and a 5-month-old bull calf. The main clinical signs consisted of exercise intolerance, dyspnea, and tachycardia. At necropsy, lesions were consistent with congestive heart failure as indicated by dependent subcutaneous edema, body cavity effusions, and nutmeg liver. The lungs were extensively atelectatic. The heart was enlarged and had a globous shape. The ductus arteriosus, measuring 0.8 cm in length and 0.4 cm in caliber, was patent. The proximal pulmonary artery had an approximately 50-mm-long aneurysm. Eccentric cardiac hypertrophy was evident primarily in the right but to a lesser degree also in the left ventricle. Additionally, there was diffuse subendocardial fibrosis in the left and right ventricle. To the best of the authors' knowledge, patent ductus arteriosus was not previously described in buffalos. Since both calves were sired by the same bull, it is possible that this cardiac anomaly has a hereditary basis.     

Patent ductus arteriosus in a 9-day-old Grant's zebra

A 9-day old Grant's zebra with a 3-day history of lethargy, weight loss, inappetance, and diarrhea was treated with ampicillin, vitamin E and selenium, and tetanus antitoxin without effect in 24 h. On transfer to the local veterinary clinic, a grade IV/VI continuous heart murmur was detected and a patent ductus arteriosus found at necropsy.     

Patent ductus arteriosus: anatomy and surgery in a cat

A 5-month-old cat with patent ductus arteriosus (PDA) and probable small ventricular septal defect had severe cardiomegaly and congestive heart failure. The cat improved slightly with medical therapy and markedly after surgical closure of the ductus. A 4th left intercostal space thoracotomy gave good exposure. The external anatomy of the PDA was similar to that of a short, wide PDA in dogs; however, the internal aortic orifice was situated more cranial than in dogs, as evidenced by preoperative cardiac catheterization. Examination 1 year later showed marked reductions in heart size and electrocardiographic amplitude. The cat was 1 of 3 with clinically diagnosed PDA at the University of Pennsylvania from 1968 to 1980. The prevalence of PDA in 14,224 cats (0.2/1,000) was significantly less than in 68,049 dogs (4.7/1,000).     

Patent ductus arteriosus repair in general practice

A 3-month-old female German Shepherd puppy was presented for routine vaccination. Clinical evaluation revealed a grade 5/6 continuous murmur with the point of maximal intensity over the left 4th intercostal space. Echocardiography revealed a patent ductus arteriosus (PDA). The PDA was closed by a team of general practitioners using the Jackson-Henderson technique, via a standard 4th intercostal thoracotomy. A multi-modal approach to analgesia and premedication was employed. A successful outcome was achieved with no murmur or evidence of cardiac disease present 6 months after surgical occlusion. The literature is reviewed with an emphasis placed on choosing techniques that are appropriate to the level of expertise of the surgical and anaesthetic teams, as well as the surgical facilities available.     

Intraoperative hemorrhage during patent ductus arteriosus ligation in dogs

OBJECTIVE: To determine the prevalence of intraoperative hemorrhage in a consecutive series of dogs undergoing patent ductus arteriosus (PDA) ligation at a veterinary teaching hospital, and to describe strategies to reduce the risk of ductus perforation and deal with hemorrhage when it occurs. STUDY DESIGN: Retrospective clinical study. ANIMALS: Sixty-four dogs. METHODS: The records of all dogs undergoing PDA ligation at the University Veterinary Center, Sydney between May 1989 and February 1998 were reviewed and the prevalence and nature of complications identified. RESULTS: Serious hemorrhage occurred in 4 of 64 dogs (6.25%) that underwent PDA ligation. In all cases, hemorrhage resulted from perforation of the craniomedial aspect of the ductus while attempting to expose the tips of the dissecting forceps. Hemorrhage was controlled in 3 dogs by clamping the main pulmonary artery, digital compression of the descending aorta, and completion of ductus ligation during an approximately 5-minute period of circulatory arrest. The remaining dog exsanguinated during an unsuccessful attempt to locate, clamp, and ligate the bleeding point. The mortality rate for PDA ligation was I of 64 dogs (1.6 %). CONCLUSIONS: The technique described in this report permits simple ligation of a range of different ductus morphologies in dogs of varying breeds, weights, and ages. In the event of serious hemorrhage, prompt ventricular outflow occlusion and ductus ligation followed by rapid whole blood transfusion is life saving in most cases.     

A wire loop technique for ligation of patent ductus arteriosus

A novel, yet simple and inexpensive, technique is described for the safe passage of suture material for closure of patent ductus arteriosus in small animals. The risk of haemorrhage is reduced by minimising dissection with forceps and by preventing inadvertent grasping of perivascular connective tissue.     

Right-to-left shunting patent ductus arteriosus with pulmonary hypertension in a cat

A 16-month-old, neutered female domestic shorthaired cat had tachypnoea, inappetence and a heart murmur, which had been first detected at eight weeks old. Diagnosis of reverse shunting patent ductus arteriosus and pulmonary hypertension was based on a detailed two-dimensional and Doppler echocardiographic examination. This report documents the clinical and imaging findings in this rare feline condition.     

Use of sodium nitroprusside in the anaesthetic protocol of a patent ductus arteriosus ligation in a dog

Patent ductus arteriosus (PDA) is one of the most common congenital cardiac abnormalities in the dog. Sodium nitroprusside has been proposed as an infusion during PDA ligation as the resultant nitric oxide production causes hypotension thereby facilitating surgical dissection and decreasing the risk of haemorrhage. This case report details how the method described did not decrease blood pressure and therefore had no beneficial effects. It is speculated that the lack of response may have been due to tachyphylaxis. Other drugs may be preferred to induce deliberate hypotension in the dog.     

Aberrant branch of the bronchoesophageal artery resembling patent ductus arteriosus in a dog

An anomalous shunt between the bronchoesophageal artery and pulmonary artery was diagnosed in a 1-year- old, 3.5 kg female Miniature Dachshund by selective contrast angiography. A cardiac murmur had been observed in the dog during examination at another hospital. The machinery murmur was auscultated at the left side of the base of the heart. Although thoracic radiography revealed mild cardiomegaly, the characteristic findings of patent ductus arteriosus (PDA), including as aortic arch enlargement and pulmonary artery enlargement were not observed. Echocardiography demonstrated shunting of blood flow presumably from the arterial duct at the pulmonary artery carina. Based on the above findings the case was diagnosed as PDA. Angiocardiography was performed to confirm the diagnosis in preparation for surgical treatment, but later we confirmed that the shunt vessel was not PDA, but apparently a branch of the bronchoesophageal artery. The shunt vessel was branching in a complicated manner and shunted to the pulmonary artery.     

A simple manoeuvre to aid in suture passage during ligation of patent ductus arteriosus

A simple manoeuvre is described which prevents incorporation of soft tissue by the forceps when passing suture around the blind (medial) side of the aorta or ductus arteriosus during ligation of patent ductus arteriosus in dogs.     

Acute onset of pulmonary necrotising arteritis in a dog with a left-to-right patent ductus arteriosus

A 12-week-old, clinically normal Chihuahua was referred for investigation for a continuous heart murmur. Cardiac evaluation revealed an anatomically and haemodynamically typical left-to-right shunting patent ductus arteriosus. The continuous wave Doppler measurement of peak ductal jet velocity of 5.6 m/s was suggestive of a normal pulmonary to systemic arterial pressure ratio. The dog returned 16 days later with right heart failure and severe pulmonary hypertension. Marked reduction in left-to-right shunting was demonstrated and the ductal jet velocity had decreased to 2.5 m/s. Immediate ductus ligation, oxygen therapy before and after the operation, and administration of hydralazine failed to reduce pulmonary hypertension, and the dog was euthanased. Histopathological examination of the lung showed pulmonary necrotising arteritis with acute and chronic arterial lesions. Chronic pulmonary vascular changes related to high flow have been associated with altered nitric oxide and endothelin responses. These changes may be responsible for the acute onset of pulmonary hypertension due to relatively minor vascular insults in some human and veterinary patients with left-to-right shunts. The potential for acute progression supports the recommendations for early ductus ligation and the prognostic importance of detecting pulmonary hypertension presurgically in patent ductus arteriosus patients.