Abstract: A smooth-walled non-crimped inflow conduit for an implantable ventricular assist system. The conduit has an internally smooth lumen surface for enhanced washing of the conduit under irregular blood flow conditions. The conduit includes a tubular graft body that may be formed of a knitted fabric sealed with bovine collagen or gelatin, or formed of closed structured PTFE. The conduit may include external ribbing or support to prevent inward collapse under negative pressure conditions and also protect against damage from inadvertent physical contact in the operating room. The external support may be bonded to the exterior or formed integrally with the tubular graft body. An outer reinforcement cage may be provided to help prevent gross distortion or damage to the tubular graft body. The ends of the tubular graft body are left unsupported and wrapped around opposed lips of conduit coupling structure to minimize blood contacting surfaces at junctions with other conduits or with the heart.