A new catheter to prevent exit-site infection in peritoneal dialysis.

In order to prevent exit-site infection, we studied a new Tenckhoff-derived catheter, named the "Malpighi catheter," capable of avoiding sinus tract formation. The outer cuff of this new device is 3.5 cm long and is deliberately positioned half-extruded; in fact, half of the cuff remains outside the skin exit-site. The implantation technique is identical to that of the standard two-cuff Tenckhoff catheter. We implanted eight Malpighi catheters in 5 CAPD and 3 IPD patients. The observation period was 146 patient-months (range 14-23, M +/- SD 18.2 +/- 3.3). We observed excellent adhesion between the outer cuff and surrounding tissue. Actually, by pulling the catheter the skin around the half-extruded cuff becomes cone-shaped, with the cone's apex tightly stuck to cuff and the sinus tract disappearing completely. Only one case of exit-site infection by Staphylococcus aureus and two cases of ulcer of the skin beneath the external part of the half-extruded cuff were observed. These complications were resolved completely. No catheter needed to be removed and there were no leakages. The histological study of the cuff showed a good infiltration of the dacron cuff by fibrous tissue. On the grounds of our preliminary experience, we believe that the absence of the sinus tract, the formation of an efficient mechanical and bacterial barrier and the reduction of exit-site infection incidence are all factors that encourage further research.