COMPLICATIONS OF BALLOON CATHETERIZATION ASSOCIATED WITH ABERRANT CEREBRAL ARTERIAL ANATOMY IN A HORSE WITH GUTTURAL POUCH MYCOSIS

A 3-year-old Quarter Horse gelding was treated for left guttural pouch mycosis by ligation and balloon catheterization of the left internal carotid artery. Catheter advancement was shorter (10 cm) than the norm ally reported distance (13-15 cm), but was observed endoscopically dur ing placement as it coursed within the internal carotid artery through the guttural pouch. The horse developed a persistently abnormal respi ratory pattern after catheter placement, failed to gain consciousness, developed pulmonary edema, and died 5.5 hours postoperatively. Postmo rtem examination revelaed an aberrant left internal carotid arterial c ourse with location of the embolectomy catheter at the junction of the basilar and caudal cerebellar arteries. Brainstem neuronal necrosis a nd alveolar and interstitial pulmonary edema were identified on histol ogical examination. Angiography may be used to identify aberrant branc hing patterns. Failure to identify and occlude aberrant branches may r esult in fatal epistaxis and Brainstem lesions. (C) Copyright 1998 by The American College of Veterinary Surgeons.