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

Background. Vascular access complications are the main cause of hospitalization in dialysis patients. The difficulty in creating and maintaining vascular access after several years on haemodialysis (HD) remains the primary problem in these patients. The femoro-femoral Thomas shunt is a permanent vascular 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 with no other possibility of regular vascular access. Methods. We retrospectively studied 27 Thomas shunts implanted in 10 patients, aged 27-75 years at the time of first shunt implantation. Prior to implantation of the Thomas shunt, these patients had experienced 80 failed vascular 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 analysed 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 were 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 years. A high blood flow (450 ml/min) was obtained, without recirculation, due to the characteristics of this shunt. Efficacy, measured as percentage urea reduction (PRU), was high (on average 77.8 +/-1.5%). The infection incidence was one episode every 37.5 patient-months, Staphylococcus species being the most commonly isolated. There were no shunt removals because of infection. 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 permanent vascular access for HD patients who have no other possibility of a regular vascular access. This shunt offers high dialysis efficacy without recirculation and an access duration comparable to AV fistulae. For these reasons the Thomas shunt should continue to be used as a vascular access in HD.