Case report: Echocardiographic and computed tomographic features of congenital bronchoesophageal artery hypertrophy and fistula in a dog

Abstract

Introduction: Studies on aberrant bronchoesophageal arteries are limited. Herein, we report a case of a multi-origin systemic-to-pulmonary shunt with suspected bronchoesophageal artery hypertrophy and fistula in a dog.

Case report: A 4-year-old castrated male beagle weighing 11 kg underwent routine medical screening. Physical examination revealed a right-sided continuous murmur of grades 1-2. Thoracic radiography revealed a mild cardiomegaly. Echocardiography revealed a continuous turbulent shunt flow distal to the right pulmonary artery (RPA) branch from the right parasternal short axis pulmonary artery view. Computed tomography demonstrated systemic-to-pulmonary shunts originating from the descending aorta at the level of T7-8, the right 5th and 6th dorsal intercostal arteries, and the right brachiocephalic trunk, which formed anomalous networks around the trachea and esophagus that anastomosed into a large tortuous vessel at the level of T6-7 and entered the RPA. Surgical ligation of multiple shunting vessels was performed. Postoperative echocardiography and computed tomography showed decreased left ventricular volume overload and markedly decreased size of the varices. Additionally, most of the shunting vessels were without residual shunt flow.

Conclusion: The present study provides information regarding imaging features and the successful surgical management of multiple systemic-to-pulmonary shunts originating from the descending aorta, right brachiocephalic trunk, and intercostal arteries and terminating at the RPA. Multimodal imaging features after surgical ligation have also been described.

Keywords: aberrant bronchoesophageal artery; aortopulmonary shunt; canine; cardiovascular anomaly; esophageal varices.

Figure 1

Preoperative Doppler echocardiography at the shunt insertion. Color-flow Doppler examination from a right parasternal short-axis view (A,B) reveals a turbulent positive continuous shunt flow entering the distal right pulmonary artery (white arrow) (systolic, 4.18 m/s; diastolic, 2.56 m/s). Postoperative Doppler echocardiography at the preoperative location of the shunt. No residual flow was seen at the location (white arrowhead) (C,D).

Figure 2

MIP images and a 3D reconstructed image of preoperative computed tomography scans. Scale bars equal 10 mm. Transverse 5-mm-thick slab MIP (A–C), dorsal 10-mm-thick slab MIP (D), sagittal 7.5-mm-thick slab MIP (E,F), and 3D reconstructed images of the heart and adjacent vessels (G). Shunt (black arrow) from the descending aorta at T8 level, which was considered the enlarged left bronchoesophageal artery (BEA) (A,E). Note that in (E), the shunt is supplying the periesophageal network (white dotted arrow). Tortuous vessels (white arrowhead) arising from the fifth and sixth dorsal intercostal arteries course forward and connect to the peritracheal network (black arrowhead) (B,F,G). On dorsal and transverse MIP images, the main shunt (white arrow) entering the distal right pulmonary artery (RPA) (black asterisk) is seen (C,D). 3D reconstructed image showing multiple tortuous vessels (white arrowhead), a network, and the main shunt vessel (white arrow) connected to the distal RPA (black asterisk). Note the aberrant tortuous vessel from the brachiocephalic trunk, which was considered the aberrant right BEA (black dotted arrow) (G).

Figure 3

View at the time of surgical ligation of the shunting vessels. The main shunt entering the right pulmonary artery (white dotted line) is identified (A). The caudal vena cava is indicated by the black arrow. Blunt separation and ligation of the shunt are performed using a surgical clip (white arrow) and 5–0 polypropylene (B,C). Identification and ligation of the shunting vessel (yellow dotted line) from the brachiocephalic trunk—which was considered the aberrant form of the right bronchoesophageal artery and right fifth–sixth dorsal intercostal arteries—is performed, and a surgical clip (white arrowhead) is observed. The white asterisk indicates the reflection of the esophagus on the malleable retractor (D–F).

Figure 4

Follow-up computed tomography (CT) images at 12 weeks postoperatively (A–F) and a reconstructed 3D image (G) for comparison. Scale bars equal 10 mm. The remaining trunk of the ligated vessel (white arrow) connected to the right pulmonary artery, which is supplied by the peritracheal network (white dotted arrow), is identified, but no connection cranial to the surgical clip (white arrowhead, 1) is observed (A,B,C,G). Note the remarkable decrease in the flow of the peritracheal network (white dotted arrow) and the ligated vessel compared with those observed in preoperative CT (D,G). Surgical clip for the ligation of the small tortuous vessel originating from the fifth and sixth intercostal arteries, which were supplying the peritracheal network (white arrowhead, 2) (C). Ligation of the shunting vessel from the brachiocephalic trunk, which was considered the aberrant right bronchoesophageal artery (BEA) supplying the peritracheal network. No remaining flow after the ligation is observed. Surgical clips for the ligation of the suspected aberrant right BEA (white arrowhead, 3) and of the small shunting vessel originating from the fifth dorsal intercostal artery (white arrow, 2) (C–F).