Transvenous detachable coiling of patent ductus arteriosus in small dogs.

OBJECTIVE: To report on transvenous detachable coiling in small dogs deemed ineligible for traditional transarterial patent ductus arteriosus occlusion and compare transthoracic echocardiographic and angiographic measurements to determine their equivalence. MATERIALS AND METHODS: A retrospective study of 35 dogs that underwent transvenous coiling of a patent ductus arteriosus. Demographic information, echocardiographic and angiographic studies, surgery reports, and follow-up evaluation of residual flow were obtained. A Bland-Altman analysis was used to compare echocardiographic and angiographic measurements of the minimal ductal diameter (Echo-MDD, Ang-MDD) and ampulla diameter (Echo-A, Ang-A). RESULTS: Thirty-four of 35 dogs had successful deployment of a coil, with one dog undergoing occlusion with a different device after the exteriorized coil pulled through the ductus. Complete occlusion was achieved in 18 dogs within 24 h; four dogs were lost to follow-up, and the remaining 12 dogs had no residual flow or a significant reduction in shunting with normalization in cardiac chamber dimensions by a median of 99 days. Thirty percent of dogs (11/35) experienced perioperative complications of which 10 were minor complications. The analysis of 26 dogs with both echocardiographic and angiographic ductal measurements showed a -0.14 mm mean difference (95% limits of agreement -1.08 to 0.8 mm) in minimal ductal diameter and -0.68 mm mean difference (95% limits of agreement -2.73 to 1.37 mm) in ampulla diameter. CONCLUSIONS: Dogs less than 3 kg deemed too small for transarterial occlusion can successfully undergo transvenous coil embolization of patent ductus arteriosus.

High-pressure balloon dilation in a dog with supravalvular aortic stenosis.

A 6-month-old female intact Goldendoodle was presented for diagnostic work up of a grade IV/VI left basilar systolic heart murmur. An echocardiogram was performed and revealed a ridge of tissue distal to the aortic valve leaflets at the sinotubular junction causing an instantaneous pressure gradient of 62 mmHg across the supravalvular aortic stenosis and moderate concentric hypertrophy of the left ventricle. Intervention with a high-pressure balloon dilation catheter was pursued and significantly decreased the pressure gradient to 34 mmHg. No complications were encountered. The patient returned in 5 months for re-evaluation and static long-term reduction in the pressure gradient was noted.