3:45 PM Abstract No. 87 Prospective study of central venous stenosis and pressure gradients in patients with fistula access

Abstract

To explore if pressure gradients (PG) correlate with degree of central venous stenosis (CVS) in dialysis patients and if PG could be a useful decision-making tool to treat CVS. Background: Dialysis patients are predisposed to CVS. Symptoms include congestion, pain, and fistula dysfunction. Percutaneous angioplasty is first-line treatment for CVS and is indicated when patients are symptomatic or when collaterals are present, regardless of symptoms. At present, it is unclear if asymptomatic CVS without collaterals affect the function of ipsilateral surgical dialysis access and if treatment of these lesions is necessary. The risk of treatment is rupture during treatment or accelerated restenosis. This prospective study selected for subjects with AV fistulas referred to our institution for a fistulagram. The indication for subjects’ fistulagram and fistula details were recorded. Venogram evaluated for stenosis percentage. PG were obtained with a Compass device measuring the difference between pre and post stenotic pressures. Caliber and PG were measured in the subclavian and innominate veins, and superior vena cava. Pre- and poststenotic PG were correlated with degree of stenosis. The presence of collaterals was noted. 16 subjects (9 male and 7 female, age 24-86 years) of which 6 subjects with fistulas demonstrated 30-70% stenosis of the brachiocephalic vein. 10 subjects did not show stenosis. 3 subjects with 30-50% stenosis had higher PG than those with no stenosis (2.7 ± 1.2 (2-4) vs. 0.6 ± 0.7 (0-2) mm Hg, P = 0.006). 3 subjects with 50-70% stenosis had PG higher than those with no stenosis of (9.0 ± 4.4 (1-16) vs. 0.6 ± 0.7 (0-2) mm Hg, P = 0.008). PG were similar in those with 30-50% stenosis and 50-70% stenosis (P = 0.22), though PG and percent stenosis had a significant positive correlation (ρ = 0.74, P = 0.001). This ongoing prospective study suggests subjects with dialysis access have elevated PG with severe CVS. PG in subjects with 30-50% or 50-70% CVS are similar. Both CVS groups had elevated PGs compared to subjects with no CVS. Across all subjects, PG was correlated with percent stenosis. Further investigation will help delineate these promising trends.