A multicenter feasibility study (Figure 1) unfortunately suggested that a low-grade rejection phenomenon was damaging the allogenic femoral vein valves, with primary patency rate of 67% and primary competency rate of only 56%.15 A two-year clinical study reported a disappointing 27% patency and competency rate.16 The cryopreserved valve allograft failed in early and midterm clinical trial, and is not considered a suitable valve substitute for treating DVI.
Another clinical investigation utilized a cryopreserved allograft pulmonary valve monocusp implanted surgically into the common femoral vein in patients with longstanding, active venous ulcerations ( 3 years).17 It was difficult to determine if the patients had an autogenous alternative, but the technique is unique.
The CQL features a higher “crack” pressure than most valves, which helps to create a higher level of hypobaric suspension.
Designed to work with liners with a seal band, the Hands Free Valve offers auto expulsion and a manual twist option that increases airflow for donning and doffing.
NONAUTOGENOUS VALVES Some investigations have never advanced past the point of a promising valve studied for hemodynamic responsiveness.
In a lyophilized cadaveric vein, a valve acts mechanically much like a native valve when rehydrated.6 The cusps withstood greater than 350 mm Hg retrograde pressure without leakage, and the closure time was 0.31 0.03 seconds. Venous reflux repair with cryopreserved vein valves. A variety of techniques have been used clinically, and improved venous hemodynamics and valve competency have been demonstrated. Glutaraldehyde-preserved venous valve transplantation in the dog. However, the majority of these valve studies await confirmation by other investigators over extended periods. The CQL Auto Expulsion Valve can be retrofit or used with new fabrication tooling for easy installation in new sockets.The built-in auto expulsion quietly expels air all day with no fuss.The standard dictionary definition of “artificial” is “not arising from natural growth.” Therefore, and for this review, an artificial venous valve is not considered as a “de novo” venous valve. Implantation of cryopreserved allograft pulmonary monocusp patch to treat nonthrombotic femoral vein incompetence. In general, two categories of artificial venous valves have been studied: valves devoid of autogenous components; and valves constructed, at least partially, from autogenous components. Ultimate responsibility for the coding of services/products rests with the individual practitioner.End-stage deep venous insufficiency is unrelenting venous hypertension with sequelae, and no standard option is available, or all options have been tried and found wanting. Even in the best hands, and with an architecturally preserved venous valve, about one-third of internal valvuloplasty repairs will fail within 5 years.3,4 Those requiring valve transposition or transplantation procedures fare less well, with only about 30% to 40% of valves competent at 5 years.3-5 In the face of unrelenting symptomatic deep venous insufficiency, and the lack of a standard treatment option, there is an opportunity for the use of an artificial venous valve. The quest to address this need has been ongoing for decades, and many avenues have been explored.