Abstract: Background Subvalvular aortic stenosis (SAS) is a common congenital disease in large-breed dogs, caused by left ventricular outflow tract obstruction due to a membranous or muscular lesion. Dogs with severe SAS are at increased risk of sudden death, heart failure, and reduced life expectancy. Interventional outcomes for SAS remain poorly defined, with existing studies limited by small sample sizes and heterogeneous techniques.
Hypothesis/Objectives Cutting balloon followed by high-pressure balloon valvuloplasty results in a clinically meaningful and sustained reduction in pressure gradients, with acceptable survival, in dogs with severe membranous SAS.
Animals Twenty-six dogs with severe membranous SAS.
Methods Retrospective case series evaluating dogs undergoing cutting balloon followed by high-pressure balloon valvuloplasty for the treatment of severe membranous SAS.
Results The median preoperative pressure gradient was 162 mmHg (86–266.6 mmHg), decreasing to a median of 74.7 mmHg (29.9–130.2 mmHg) immediately postoperatively. Pressure gradients increased at 3 months to a median of 99.6 mmHg (54–155 mmHg) and remained stable at subsequent follow-up visits. At the last follow-up, 9/26 dogs had died, with a median age at death of 996 days (179–2,495 days). Fourteen of 26 dogs remained alive at last follow-up, with a median age of 2,396 days (652–4,977 days). One dog was lost to follow-up, and two dogs died intraoperatively. Postoperative pressure gradients returned to or exceeded preoperative values in 4/26 dogs.
Conclusions and Clinical Importance Combined cutting balloon and high-pressure balloon valvuloplasty provides substantial and durable pressure gradient reduction with acceptable survival in selected dogs with severe membranous SAS.
