STEPHEN ASH

Home dialysis is principally limited by the inherent technical complexity of the procedure. Presentations in this session described improvements in techniques that could increase the practicality of home hemodialysis.

Mahendra Agraharkar, MBBS, from the University of Texas Medical Branch, Galveston, Texas, described five episodes of problems of bleeding from central venous catheters. One episode was due to a manufacturing defect. Two episodes occurred in the first 6 – 7 days after placement, due to pinhole punctures of the catheter that did not leak until the dialysis procedures were implemented (as blood flow caused increased pressure within the catheter). Suturing at the exit site resulted in these small punctures near the exit site. Two other bleeding episodes occurred 6 – 8 weeks after placement. Tight sutures around a grommet (stabilizer or suture wing) on the catheter resulted in external forces that cut the catheter as it expanded due to internal pressure. Catheters with wings on the Y-connector can be sutured directly to the skin reasonably safely. For other catheters, a transparent adhesive dressing can be applied to the catheter in a sandwich technique, securely fixing the catheter at the skin exit site.

Stephen Ash, MD, PhD, Purdue University and HemoCleanse, Inc., West Lafayette, Indiana, described a new system for hemodialysis that is simple, safe, and automated. As opposed to standard dialysis machines that pump blood volumetrically and measure pressure, the HemoCleanse-HD™ system pumps blood under constant pressure and measures the blood flow rate. A standard plate dialyzer attaches to a single-lumen catheter or fistula cannula, and vacuum and pressure applied to the dialysate causes membrane motion to pump the blood. Other features include blood tubing leak detection, inflow and fluid replacement line bubble detection, automated fluid return and final rinse, and completely disposable blood-side and dialysateside components. The system has been tested in 12 end-stage renal disease (ESRD) patients, with 4- to 5-hour treatments. Chemical effectiveness and biocompatibility are similar to dialysis with standard dialyzers at blood flow rates of 200 – 250 mL/min. Used for 8 hours of dialysis overnight with 80 – 100 L of dialysate, the system should result in effective, economic, and safe therapy for ESRD.