Prevention of hemodialysis fistula thrombosis. Early detection of venous stenoses

Abstract

Venous dialysis pressures were measured consecutively in 168 chronic hemodialysis patients for 265 patient-years of monitored dialysis. Venous dialysis pressure greater than 150 mm Hg measured by the protocol were considered elevated. Seventy-three patients had elevated venous dialysis pressures and 58 agreed to undergo elective venography (fistulogram). Fifty of 58 patients studied (86%) had significant venous stenoses. A combination of percutaneous transluminal angioplasty (PTA) and surgical revision were used to electively treat these stenoses. Early detection and treatment of these stenoses decreased fistula thrombosis and fistula replacement threefold compared with our earlier experiences. Patients with elevated venous dialysis pressure who were venogramed and treated had an occurrence of fistula thrombosis similar to patients with normal dialysis pressure (0.15 and 0.13 episodes per patient year of dialysis respectively, P = NS). In contrast patients with elevated venous dialysis pressure who refused elective fistulogram and treatment averaged 1.4 episodes of thrombosis per patient year of dialysis (P less than 0.001) compared to both other groups). We conclude that elevated venous dialysis pressure is a reliable method of detecting fistula stenoses and that the elective treatment of these stenoses significantly decreases fistula thrombosis and fistula loss.

Comparison of Arteriovenous Grafts in the Thigh and Upper Extremities in Hemodialysis Patients

“…When the stenosis is not detected and corrected in a timely manner, grafts typically clot and require thrombectomy to restore their patency. A number of studies have found that an ongoing surveillance program for graft stenosis and timely intervention with angioplasty or surgical revision can substantially reduce (but not eliminate) the frequency of graft thrombosis (13,(23)(24)(25)(26). In the present study, thigh grafts tended to have less frequent angioplasties and more frequent thrombectomies than did upper extremity grafts (Table 3).…”

Influence of Luminal Diameters on Flow Surveillance of Hemodialysis Grafts

“…The in vitro study showed that the graft and the vein exhibit turbulent flow, whereas the artery may exhibit laminar entry flow or turbulent flow, depending on the Reynolds number: Re ϭ Q/15D ( is blood density in g/cm 3 , Q is in ml/min, and D is diameter in cm) (16). We found that as Re increased above 1500 in the artery, flow became turbulent (17).…”

“…This preference is based on the assumption that progressive stenosis causes a gradual reduction in Q that leads to stasis and thrombosis (2). Landmark nonrandomized studies reported that surveillance of function improves graft outcomes (3,4), but more recent randomized controlled trials have not confirmed this (5-7). Moreover, monthly Q measurements have proved to be an inaccurate predictor of thrombosis (8 -11).…”

Avaliação do acesso vascular para hemodiálise em crianças e adolescentes: um estudo de coorte retrospectivo de 10 anos

“…26,33 Approximately 80% of thrombotic events are related to venous stasis produced by stenotic lesions. 38 Excessive vessel compression after needle withdrawal, to avoid bleeding, and intradialytic and post-dialytic hypotensive episodes, which are frequent in children, are also important causes of thrombosis. 39 Although not computed in this study, our long experience in HD pediatric units has shown that hypotension is frequent during HD sessions, chiefly with inadequate ultrafiltration calculation or removal of too much water too fast.…”