Closed aortic valvotomy: a retrospective study in 15 dogs

The results of closed, transventricular valvotomy in 15 dogs with subvalvular aortic stenosis (SAS) were evaluated in a retrospective study. Fourteen dogs ranged from five to 10 months of age; one dog was 42 months of age at the time of surgery. A combination of physical examination, thoracic radiography, electrocardiography, echocardiography, Doppler ultrasonography, and cardiac catheterization was used to establish a definitive diagnosis. Of the 15 dogs undergoing surgery for SAS, 13 had both two-dimensional (2-D) and M-mode echocardiographic examinations; three had successful Doppler aortic blood-flow studies; and five had successful cardiac catheterizations with selective ventricular angiography and intracardiac pressure measurements. In the five dogs undergoing preoperative catheterization, pressure gradient measurements across the aortic valve ranged from 58 to 130 mm Hg. Gradients were reduced by 55% (from 58 to 26 mm Hg), 54% (from 65 to 30 mm Hg), and 30% (from 93 to 65 mm Hg) in three dogs measured postsurgically at 2.5 months (n = 2) and four months (n = 1), respectively. The 10 surviving dogs that were available for follow-up were free of clinical signs of cardiac disease postoperatively.