FINE TRABECULARIZED CARBON - IDEAL MATERIAL AND TEXTURE FOR PERCUTANEOUS DEVICE SYSTEM OF PERMANENT LEFT-VENTRICULAR ASSIST DEVICE

The development of a percutaneous artificial internal organ system req uires a reliable biocompatible connection between the external environ ment and the inside of the human body. Such is necessary for the succe ss of a permanent left ventricular assist device. However, the search for a satisfactory interface at the epidermal level has proven to be d ifficult. Carbon has been proposed for this application, but its textu re does not typically promote ingrowth from surrounding tissue. We hav e therefore employed a new processing method to produce a fine trabecu larized carbon implant. The method for preparing the implant involves infiltrating low temperature pyrolytic carbon into the surface of a ca rbon core which is wrapped with carbon fabric. This results in a tight ly woven porous structure of carbon (carbon fiber diameter: 35-50 mu m , maximal pore size >200 mu m) with gradually increasing porosity from 15-75%. We implanted test samples percutaneously in a calf for in viv o histological evaluation. Thirty days after implantation epidermal do wngrowth was minimal. Microscopic analysis revealed that a thin fibrou s capsule surrounded the implant, and mature connective tissue with ac companying blood vessels filled the pores of the fine trabecularized c arbon layer. From these results we suggest that fine trabecularized ca rbon is ideally suited for a percutaneous device system in a permanent left ventricular assist device.