Retrospective evaluation of occlusion of patent ductus arteriosus with hemoclips in 20 dogs

Twenty dogs with patent ductus arteriosus occluded with Hemoclips were eval uated with a mean follow-up time of 799.4 days (range, 83 to 3,580 days). S ignificant decreases were found between pre- and postsurgical means for ver tebral heart size and for echocardiographic left atrial/aortic-root ratios and percent fractional shortening (%FS). Despite a good clinical outcome, s ix of 20 dogs had persistent cardiomyopathy of overload with diminished %FS (28% or less) at follow-up. One dog had residual ductal flow identified fi ve days postoperatively. Subsequent evaluations in this case at 60, 144, 22 6, 344, and 560 days postoperatively demonstrated gradually diminishing duc tal flow. The remaining 19 dogs did not recanalize.