Long-term experience with the Thomas shunt, the forgotten permanent vascular access for haemodialysis

Background. Vascular access complications are the main cause of hospitaliza tion in dialysis patients. The difficulty in creating and maintaining vascu lar access after several years on haemodialysis (HD) remains the primary pr oblem in these patients. The femoro-femoral Thomas shunt is a permanent vas cular access that was used in the 1970s and is all but forgotten at present . We analysed our experience with the Thomas shunt since 1979 in patients w ith no other possibility of regular vascular access. Methods. We retrospectively studied 27 Thomas shunts implanted in 10 patien ts, aged 27-75 years at the time of first shunt implantation. Prior to impl antation of the Thomas shunt, these patients had experienced 80 failed vasc ular accesses (plus four patients on CAPD), with an average of 8.6 accesses per patient. All Thomas shunts were implanted in femoral vessels. Clinical data were extracted from hospital and dialysis unit records and were analy sed for efficacy, complications, and duration of patency. Results. Total follow-up was 1176 months, with an average shunt duration of 43.7 months (range 3-151 months). One-, 2-, 3- and 6-year survival rates w ere 85, 57, 49 and 25% respectively. Five patients spent more than 10 years on HD using the Thomas shunt, and one patient had the same unit for 12.5 y ears. A high blood flow (450 ml/min) was obtained, without recirculation, d ue to the characteristics of this shunt. Efficacy, measured as percentage u rea reduction (PRU), was high (on average 77.8 +/-1.5%). The infection inci dence was one episode every 37.5 patient-months, Staphylococcus species bei ng the most commonly isolated. There were no shunt removals because of infe ction. The most important cause of shunt withdrawal was thrombosis, with an incidence of one episode every 7 patient-months. Percutaneous angioplasty was successful in the majority of stenosis episodes. Conclusions. This study indicates that the Thomas shunt provides a good per manent vascular access for HD patients who have no other possibility of a r egular vascular access. This shunt offers high dialysis efficacy without re circulation and an access duration comparable to AV fistulae. For these rea sons the Thomas shunt should continue to be used as a vascular access in HD .