Transcatheter implantation of a bovine valve in pulmonary position - A lamb study

Background-Pulmonary regurgitation can lead to severe right ventricular dysfunction, which is a delicate postoperative problem in the long-term follow-up of patients who had surgery for congenital heart diseases. Clinical conditions of patients suffering from pulmonary valve incompetence are improved by valve replacement with a prosthetic valve. To date, the surgical approach is the only option to replace a pulmonary valve. We report the first experience of percutaneous pulmonary valve implantation. Methods and Results-A fresh bovine jugular vein containing a native valve was sutured into a vascular stent and then cross-linked with a 0.6% glutaraldehyde solution for 36 hours. After being hand-crimped onto a balloon catheter, the device was inserted percutaneously according to standard stent-placing techniques. The valved stent was finally deployed in the position of the native pulmonary valve of the lamb. Hemodynamic evaluation was carried out before and 2 months after implantation. Anatomic evaluation was finally performed. Percutaneous pulmonary valve replacement was successful in 5 lambs. No complications were noted. Early and late angiographic and hemodynamic studies confirmed a good position of the stents with a competent valve at the end of the protocol. One stent was slightly stenotic, with macroscopically visible calcifications. Conclusion-Nonsurgical implantation of pulmonary valves is possible in the lamb. This new technique is similar to standard stent implantation. Thus, it should be feasible in humans, in whom it will lead to a significant reduction of reoperations in patients in need of pulmonary valve replacement.