Six months clinical, angiographic, and IVUS follow-up after PTFE graft stent implantation in native coronary arteries

Abstract

Introduction: Restenosis remains a problem even after stent implantation. An important breakthrough could be the use of graft stents, functioning as a mechanical barrier between the blood flow and the vessel wall, and possibly inducing less restenosis by more limited hyperplasia and minimal transgraft tissue penetration.

Objective: To assess the acute and 6 months clinical, angiographic and IVUS results of a new balloon expandable coronary polytetrafluoroethylene (PTFE) graft stent (Jomed).

Method: Ten patients with a short (< or = 15 mm length) de novo proximal stenosis in a large (> or = 3 mm diameter) coronary artery were treated by elective implantation of a graft stent (19 mm stent, 15 mm graft). Clinical assessment, quantitative coronary angiography (QCA) and intracoronary ultrasound (IVUS) were performed before, immediately after and 6 months after implantation. A stress test was also done at 6 months.

Results: The coronary arteries treated were: RCA in 7 patients, LCX in 2 patients, LAD in 1 patient. Mean balloon size was 3.7 mm diameter, and mean inflation pressure was 18 atm (min. 12, max. 23). Additional stenting was needed in 3 patients. Two patients showed a minimal rise in CK (< 250 IU/l) and 1 patient needed a transfusion. No patient experienced a (sub)acute nor late thrombosis. As shown in the table, no restenosis was seen in the body of the graft stent. In 2 patients a restenosis was detected in the proximal and/or distal parts of the stent which are not covered by the graft. In 1 patient a restenosis was found outside the stent. All patients remained asymptomatic with a negative stress test at 6 months follow-up (FU). [table in text]

Conclusions: A graft stent could indeed reduce the restenosis rate after stenting, in the part of the stent covered by the graft, but the uncovered distal and proximal parts are the weak points in this type of stent. For this reason, technical ameliorations in the construction of this graft stent are needed, e.g. a complete coverage of the stent by the PTFE graft and less rigidity of the stent causing reduced vessel trauma at the edges of the stent during implantation.