Venous disease

In this report we describe the outcome of a 6-week study of the valvestent device in a goat model. Six female goats underwent endoscopic subcutaneous harvest of a valve-containing segment of external jugular vein. This segment was sutured inside a 10-mm Wallstent (Schneider Inc., USA), and the device was compressed and loaded into a 12 Fr. introducer sheath and deployed through a venotomy into the contralateral external jugular vein. The animals were anticoagulated for 1 week and euthanized at 6 weeks. Flow studies, manual strip test, and angioscopic evaluation were performed prior to sacrifice. All six valve-stents were patent at harvest by Doppler flow studies, and five of six were competent as demonstrated by the manual strip test. At angioscopic evaluation, the valves were open. Gross and histologic examination revealed intact valve leaflets in five specimens. This technique is a minimally invasive approach to valve harvest and transplantation with a valve-stent device. We have demonstrated that valve-stent can remain patent and competent for up to 6 weeks. This technique may have potential application in venous valvular incompetence.

Purpose: We investigated the mechanical characteristics of lyophilized human saphenous vein valves to determine their suitability for use as allogeneic transplants to treat chronic venous insufficiency.

Methods: Fresh cadaveric veins were lyophilized in vacuum bottles within 24 hours of harvest and were stored at room temperature. The veins were reconstituted in saline solution and then were placed in an in vitro flow circuit for evaluation. At varied flow rates, pressures proximal and distal to valves during prograde and retrograde flow were measured. Valve closure times were determined with Doppler examination and spectral analysis. The valves were also stressed to 350 mm Hg on a separate apparatus.

Results: All pressures proximal and distal to the valves remained less than 10 mm Hg during prograde flow. A pressure gradient developed immediately on the reversal of flow. Pressure as high as 200 mm Hg applied against the closed valves was not transmitted beyond the valve. Valve closure times had a mean of 0.31 ± 0.03 seconds and 0.21 ± 0.01 seconds for the Doppler examination and spectral analysis, respectively. All valves withstood stress pressures to 350 mm Hg.

Conclusions: The in vitro mechanical characteristics of the valves of lyophilized veins are similar to known values for normal in vivo valves. (J Vasc Surg 1997;26:823-8.)

Purpose: Most epidemiologic studies on chronic venous insufficiency (CVI) are cross-sectional surveys that suggest potential risk factors by describing their population. However, these relationships could be due to the CVI population's older age. We performed a dual case-control study with multivariate analysis to address this issue.

Methods: Ninety-three patients with venous ulcers, 129 patients with varicose veins (VV), and 113 general population control patients from two hospitals were interviewed by use of a standardized questionnaire covering medical history, patient demographics, medications, and lifestyle questions. Univariate and multivariate analyses were used to compare the groups.

Results: Univariate analyses showed CVI to be characterized by several factors, many of which were found to be age related after multivariate analysis. Age-adjusted relationships for CVI include male sex and obesity. Histories of serious leg injury or phlebitis were important associations resulting in a 2.4-fold and 25.7-fold increase in risk for CVI, respectively. After adjusting for age, subjects with VV tend to be younger and female, to more frequently have a history of phlebitis, and to report a family history of VV more frequently than control subjects.

Conclusions: Many of the previously suggested associations found with CVI are in reality due to this population's greater age. Patients with CVI are older, male, obese, have a history of phlebitis, and have a history of serious leg injury. These results suggest that a prior deep vein thrombosis, either clinical or subclinical, may be a predisposing factor for CVI. (J VASC SURG 1995;22:622-8.)