Valve transplantation to the canine popliteal vein: the utility of a distal arteriovenous fistula and the hemodynamic result of a single functional valve

Abstract

Purpose: The objectives were to transplant a venous valve into the popliteal vein of a canine insufficiency model that would maintain long-term function and then to measure the hemodynamic benefit of such a valve.

Methods: Indexes of venous valvular function, including venous filling time, 90% of venous refilling time, and simulated ambulatory venous pressure, were measured in 11 greyhounds before intervention (Control) and after hind limb venous valvulotomy, which produces chronic venous insufficiency. Three weeks later a valve-containing segment of external jugular vein was transplanted to the popliteal vein with (n = 6) or without (n = 5) a distal arteriovenous fistula. The fistula was ligated in 4 to 6 weeks. Repeat venous indexes were obtained an average of 2 weeks after the last operative intervention. Gross anatomic inspection +/- duplex scanning performed before the animals were killed were used to distinguished normal from damaged valves.

Results: Four of five simple valve transplants demonstrated scarring and/or thrombosis and the average venous filling time, ambulatory venous pressure, and 90% of venous refilling time were consistent with chronic venous insufficiency and/or obstruction. One fistula failed in the six valve distal arteriovenous fistula transplants, and that valve was incompetent. Analysis of the remaining five functional valves demonstrated venous filling time consistent with chronic venous insufficiency, normalization of ambulatory venous pressure, and 90% of venous refilling time between normal, and chronic venous insufficiency. These valves appeared normal.

Conclusions: Popliteal vein valve transplant anatomy is preserved by an adjunctive distal arteriovenous fistula, and a competent valve transplant improves postexercise venous hemodynamics to approach those of a normal limb.