In vivo biomechanical properties of three different graft materials in peripheral vascular surgery

Abstract

Compliance is one of the most decisive biomechanical characteristic features of the graft wall as well as the vessel wall influencing the success of vascular reconstruction.

In the following study we noninvasively investigated graft-arterial compliance alterations in vivo after surgery with M-mode ultrasound in 99 patients with various graft materials over an extended follow-up period between 3 months and 10 years.

During a one year period in vivo graft compliance was measured with M-mode ultrasound in 49 implanted bifurcation grafts and 68 femoropopliteal reconstructions of 99 patients (25 female and 74 male). For bifurcation grafts Dacron and for femoropopliteal reconstruction either Dacron, polytetrafluoroethylene (PTFE) or autologous saphenous vein were used.

The in vivo compliance of gel-coated Dacron bifurcation grafts and femoropopliteal grafts declined with increasing time following implantation.

The compliance of bifurcation grafts depended on the patency of the outflow tract. In case of an occluded superficial femoral artery with main outflow through the deep femoral artery graft compliance declined about 51% over 5 years after implantation. In contrast, in case of a patent superficial artery the reduction of graft compliance was only 37%.

In all femoropopliteal grafts the decrease of graft compliance over 5 years after implantation depended on the graft material. With a better initial compliance autologous vein grafts were more compliant at all times in the follow-up in comparison with PTFE or Dacron grafts.

The ability to measure noninvasively in vivo graft compliance with M-mode ultrasound may enable to estimate early patency problems and at least graft failure depending on graft material and time after implantation.