Coil embolization of an aorticopulmonary fistula in a dog

Abnormal movement of the pulmonary valve in dogs diagnosed with patent ductus arteriosus

In the typical left-to-right patent ductus arteriosus (PDA), the shunt flows from the ductus arteriosus towards the pulmonary valve. Although hemodynamic changes have been carefully studied in dogs with PDA, there is very little information on the outcomes of the pulmonary valve after surgical correction of PDA. This study aimed to visualize the pulmonary valve by transthoracic echocardiography in dogs with PDA before and after surgical ligation. Prior to surgery, the movement of the anterior semilunar cusp of the pulmonary valve was obstructed by the shunted blood flow during systole in all nine dogs with PDA in this study. M-mode echocardiography revealed a continuous trajectory of the cusp, because the cusp was pushed towards the right ventricle during the whole cardiac cycle by the shunted flow. Epicardial echocardiography performed in one dog during surgical ligation of the ductus arteriosus revealed that the movement of the anterior semilunar cusp normalized immediately after ligation. B- and M-mode echocardiography may be used to support the diagnosis of PDA through observation of the pulmonary valve when color Doppler echography is not available. The findings in this study may be of importance in distinguishing PDA from PDA-mimicking diseases worth considering before the treatment process (e.g. aorticopulmonary fistulas or aberrant arteriovenous shunts).

Transcatheter embolization of systemic-to-pulmonary artery fistulas in a dog using embolization coils and silk suture

A 4-month-old intact female Cavalier King Charles spaniel presented for evaluation of a left, basilar continuous murmur. Transthoracic echocardiography suggested anomalous vessels around the main pulmonary artery, and computed tomography angiography revealed two systemic-to-pulmonary artery fistulas. Transcatheter embolization of these fistulas was achieved with a combination of embolization coils and silk suture threads delivered through a microcatheter.

Clinical, echocardiographic and advanced imaging characteristics of 13 dogs with systemic-to-pulmonary arteriovenous fistulas

OBJECTIVES

The objective is to describe the clinical, radiographic, echocardiographic and angiographic findings in dogs with systemic-to-pulmonary arteriovenous fistula (SPAVF).

ANIMALS

Thirteen medical records of client-owned dogs with a diagnosis of SPAVF were reviewed/analysed.

METHODS

This is a retrospective study of case records. Thoracic radiography, transthoracic echocardiography (TTE), transesophageal echocardiography (TEE), three-dimensional TEE, intracardiac echocardiography, fluoroscopy-guided or computed tomography (CT) angiography were carried out.

RESULTS

Based on the TTE, SPAVF was identified in seven of the included dogs. In eight cases, TEE and angiography were both performed and confirmed the diagnosis. Computed tomography angiography was performed in three dogs. A case was diagnosed by TEE alone, another one by three-dimensional TEE and the latter by intracardiac echocardiography.

CONCLUSIONS

Transthoracic echocardiography identified seven cases of SPAVF, while definitive diagnosis in the remaining dogs required selective angiography or computed tomography angiography.

Use of an Amplatz Canine Ductal Occluder (ACDO) device to close an acquired aortopulmonary fistula with a hybrid approach in a dog

A 2-year-old recently spayed female Rottweiler was referred as an emergency with cardiac tamponade and the presence of an anomalous retrograde flow in the pulmonary artery. Echocardiography and angiography demonstrated a left-to-right aortopulmonary fistula. Clinical history and data indicated a possible infectious aetiology. Antibiotics and heart failure medications were administered for 30 days before intervention. Initial attempt at insertion of an Amplatz occluder by means of a percutaneous catheterization technique was tried but a safe release of the device was judged to be not possible due to the angle and the fragile and irregular margins of the window. A decision was made to proceed with a hybrid technique combining thoracotomy and direct pulmonary artery catheterization. This hybrid approach was successful with resolution of congestive heart failure with only residual mild paraprosthetic leakage.

MULTIDETECTOR-ROW COMPUTED TOMOGRAPHY PATTERNS OF BRONCHOESPHAGEAL ARTERY HYPERTROPHY AND SYSTEMIC-TO-PULMONARY FISTULA IN DOGS

Anomalies involving arterial branches in the lungs are one of the causes of hemoptysis in humans and dogs. Congenital and acquired patterns of bronchoesophageal artery hypertrophy have been reported in humans based on CT characteristics. The purpose of this retrospective study was to describe clinical, echocardiographic, and multidetector computed tomography features of bronchoesophageal artery hypertrophy and systemic-to-pulmonary arterial communications in a sample of 14 dogs. Two main vascular patterns were identified in dogs that resembled congenital and acquired conditions reported in humans. Pattern 1 appeared as an aberrant origin of the right bronchoesophageal artery, normal origin of the left one, and enlargement of both the bronchial and esophageal branches that formed a dense network terminating in a pulmonary artery through an orifice. Pattern 2 appeared as a normal origin of both right and left bronchoesophageal arteries, with an enlarged and tortuous course along the bronchi to the periphery of the lung, where they communicated with subsegmental pulmonary arteries. Dogs having Pattern 1 also had paraesophageal and esophageal varices, with the latter being confirmed by videoendoscopy examination. Authors conclude that dogs with Pattern 1 should be differentiated from dogs with other congenital vascular systemic-to-pulmonary connections. Dogs having Pattern 2 should be evaluated for underlying pleural or pulmonary diseases. Bronchoesophageal artery hypertrophy can be accompanied by esophageal venous engorgement and should be included in the differential diagnosis for esophageal and paraesophageal varices in dogs.