First reported long-term two- and three-dimensional echocardiographic follow-up with histopathological analysis of a transcatheter pulmonary valve implantation in a pet dog.

Transcatheter pulmonary valve implantation (TPVI) is indicated for use in the management of failing pulmonary valves in humans. We report here the long-term follow-up of the first documented transcatheter pulmonary valve implanted in a client-owned dog.A 1-year-old Beagle dog with severe congenital type A valvular pulmonic stenosis first underwent percutaneous balloon pulmonary valvuloplasty leading 2 years later to severe pulmonary regurgitation. A TPVI using a Melody™ bioprosthetic valve was then successfully performed, with normalization of the right heart cavities.Repeated two- and three-dimensional transthoracic echocardiographic examinations combined with Doppler modes confirmed the appropriate position and function of the valve for 4 years. Mitral myxomatous valvular degeneration led to refractory left-sided congestive heart failure, and the dog was humanely euthanized. After postmortem examination, X-ray imaging and histopathological evaluation of the stent and the valve were performed. Ex-vivo imaging of the implanted valve using a Faxitron® Path radiography system and microscopic evaluation of the implanted stent and bioprosthetic leaflets did not show any significant leaflet or stent alterations.This case provides a proof-of-concept in interventional veterinary cardiology showing that TPVI can be performed in dogs with subsequent long-term maintaining normal pulmonary valve function.