LAUSR

To the Editor: We read with interest the paper by Sinha et al regarding initial results from the off-label use of the Edwards SAPIEN 3 (S3) valve for percutaneous transcatheter pulmonary valve implantation. The introduction of the S3 valve represents progress for the treatment of patients with larger right ventricular outflow tracts (RVOTs). Furthermore, the availability of a relatively small sized delivery system (14 Fr for the 20, 23, and 26 mm valves and 16 Fr for the 29 mmvalve) may facilitate its use in smaller patients. However, there are concerns related to the relatively high rate of complications (four of 50 patients) including new aortic regurgitation and tricuspid regurgitation needing surgical treatment. The most common valve-related complication is the development of tricuspid regurgitation in three of 50 patients. In one case, it was related to maneuvers during the prestenting part of the procedure while in the other two cases it appeared to be related to the valve implantation itself. Recently, we reported similar complications in three of 40 cases undergoing transcatheter pulmonary valve implantation using the Edwards SAPIEN XT valve. Furthermore, in the same paper, we also reported that one out of 20 SAPIEN 3 implants developed a significant tricuspid regurgitation after valve implant. As pointed out by Sinha et al, one potential cause may be that the valve has to be advanced in a “non-protected way” through the tricuspid valve, potentially entrapping tricuspid valve apparatus. Furthermore, this risk may be amplified by the need for multiple maneuvers that are sometimes needed to advance the assembly through dilated ventricles or the dilated RVOT. Finally, the presence of a stent in the RVOT may give a further source of impairment to an easy valve delivery. Various options could be available in order to reduce the risk of such complications including the use of balloon tipped catheters to cross the tricuspid valve at the beginning of the procedure or the use of echocardiographic imaging to check valve status at every stage of the procedure. Perhaps, the most obvious relevant advance would be the use of a long sheath that would cover and protect the valve as it traverses the right heart, potentially reducing the risk of tricuspid valve damage. In this regard, we have used the GORE DrySeal Flex Introducer Sheath with hydrophilic coating in six patients needing SAPIEN 3 valve in the pulmonary position. It is designed for endovascular repair of abdominal aortic (AAA) and thoracic aortic (TAA) aneurysms; however, the indications for use describe that it is intended to be inserted in the vasculature to provide a conduit for the insertion of endovascular devices while minimizing blood loss associated with such insertions. Furthermore, it is kink resistant and highly flexible to deal with complex anatomical substrates. It is available in sizes from 12 Fr to 26 Fr and in 33 cm and 65 cm lengths. The longer length is available for sheath sizes ranging from 20 to 26 Fr. In our experience, we have used the 22 Fr 65 cm long sheath that was in all cases long enough to protect the tricuspid valve while advancing the valve through it and to reach the pulmonary artery trunk making the procedure relatively easy. In the discussion section, the authors too pointed out that “ultimately, a covered system might avoid this complication”. Our experience with Gore DrySeal system is in its initial stage and future studies will determine whether this might be a way of preventing tricuspid valve damage associated with SAPIEN valve implantation.