Prospective investigation of a subcutaneous, implantable central venous access device for therapeutic plasma exchange in adults with neurological disorders.

Standard alternatives to antecubital access for long-term therapeutic plasma exchange, including percutaneous polyurethane or tunneled silicone catheters, are associated with complications and inconvenience for the patient. We have investigated the Bard CathLink 20, a subcutaneously implantable central venous access device, as an alternative for outpatient plasma exchange. The CathLink 20 consists of a funnel-shaped titanium port connected to a soft polyurethane-derived catheter and is accessed percutaneously using an 18-gauge catheter-over-needle Angiocath. Six patients with paraproteinemic polyneuropathies underwent 64 outpatient plasma exchanges using the CathLink 20 for access, 31 using 2 CathLink 20's (draw and return), 20 using a single CathLink 20 as the draw site and 13 using a single CathLink 20 as the return site. Mean (+/- SD) plasma removed was 3,680 +/- 551 ml in 115.2 +/- 25.3 min. Apheresis personnel were able to access the ports in 1.23 +/- 0.6 attempts per port per procedure. Six of 70 planned procedures were aborted: 3 because of failure of an antecubital access site and 3 because of catheter occlusion resolved using a thrombolytic agent. Whole blood flow rate was approximately 54 ml/min, and plasma flow rate was about 32 ml/min for 135 min. Access pressures were stable at -150 to -200 torr (P = 0.1395). Return line pressures varied between 90 and 130 torr (P = 0.0147). No patient required hospitalization during the study. Though not optimized for apheresis, the CathLink 20 provides a reasonable option for chronic apheresis patients who lack adequate peripheral venous access.