title: A temporary distal arteriovenous fistula improves venous hemodynamics in a model of venous occlusion.
abstract: The formation of a temporary distal arteriovenous fistula (dAVF) has been used clinically to palliate patients with symptomatic venous hypertension. This study tested the efficacy of a temporary dAVF for the treatment of venous hypertension in an experimental model. Twenty-four New Zealand white rabbits were divided into two experimental groups. Group I rabbits (n = 12) underwent standardized ligation of the iliac and femoral venous systems. Group II rabbits (n = 12) underwent standardized ligation of the iliac and femoral venous systems with the formation of a temporary dAVF. Venous obstruction was documented with venography, and venous hypertension was documented with femoral venous pressure measurements. Venous pressure, resistance, blood flow, vein circumference, vein cross-sectional area, vein wall thickness, and venography were compared between four rabbits from each group at 2, 4, and 8 weeks. The effect of differences in baseline venous pressures was eliminated by subtracting the venous pressure in the unobstructed rabbit limb from the pressure in the obstructed rabbit leg. Group II rabbits had a lower standardized venous pressure (4.4 +/- 2.2 versus 9.5 +/- 4.2 mm Hg, p less than 0.01) and venous outflow resistance (0.16 +/- 0.08 versus 0.36 +/- 0.18, p less than 0.05) than did group I rabbits. Group II rabbits also had a larger superficial femoral vein circumference (3.46 +/- 0.67 versus 2.57 +/- 0.08 mm, p less than 0.05) and cross-sectional area (0.66 +/- 0.31 versus 0.31 +/- 0.09 mm2, p less than 0.01) than did group I rabbits. The improvement persisted throughout the 6-week study, which suggested an improved venous outflow.
mesh_terms: D000818:Animals; D001166:Arteriovenous Shunt, Surgical / Q000379:methods*; D006973:Hypertension / Q000503:physiopathology / Q000601:surgery*; D008026:Ligation; D010166:Palliative Care; D010690:Phlebography; D011817:Rabbits; D014652:Vascular Diseases / Q000601:surgery*; D014680:Veins / Q000601:surgery*; D014690:Venous Pressure