[Vascular access validity and treatment efficiency in hemodialysis]

Abstract

The vascular access is the "Achille's heel" of the modern hemodialysis. In order to obtain a good depuration, the blood flow in dialysis must be of 250-300 mL/min, at least. The procedures for the preparation and their complications are cause of the 25% of the hospital admissions in patients with chronic uremia in substitutive therapy. Gold standard is still represented from the distal arteriovenous fistulas of Cimino and Brescia. The alternatives to the native veins as the syntetic graft and the tunneled central venous catheteters or the Dialock system, revealed useful in the patients that have exausted the superficial veins, but are of second choice. The native fistula has an advanced validity, demonstrated from lower risk of mortality in the patients who use it, diabetic or not. These affirmations come just from USA, where the arteriovenous grafts prevail and the percentage of central venous catheters is elevated. Thrombosis, infections and reduced depurative efficiency are the main causes. In the Dialysis Unit of Mantova we adopted an aggressive approach to the construction of distal fistula. Out of 172 patients in chronic hemodialysis, 165 use an arterovenous fistula, 4 an arterovenous grafts (PTFE) and 3 a tunnelled central venous catheters (2 Permcath and 1 Tesio). The surgical activity between 1987 and 2001 included 858 procedures on 516 patients (medium ages 59.1 years): Among these, 815 are created from native veins, 28 by arterovenous graft fistulas and 15 with tunnelled hemodialysis catheters. Our current strategy recommended to candidate to permanent venous catheter only patients on chronic hemodialysis with exhausted periferal vascular bed and only when peritoneal dialisys is'nt possible. Generally, the management of the vascular access must preview one tight collaboration between nephrologists, nurses, patient, vascular surgeons and radiologists.