Venous Return Assist Devices for Intermittent Claudication: A Randomized Controlled Trial Utilizing a Sham Comparator

Abstract

Objectives: To determine whether an intermittent mechanical compression device (Venowave) effects walking distance in patients with intermittent claudication as compared to placebo, as well as to review the published literature on the topic. Design: Randomized, cross-over, blinded trial of an intermittent mechanical compression device (Venowave), compared with a sham compression device. Setting: Hamilton Health Sciences, Hamilton, Canada. Participants: 27 patients with severe peripheral limb ischemia, as identified by at least one of: i) ABI<0.4; ii) ACD<200 m (Fontaine stage IIb); iii) toe-brachial index<0.5; or iv) toe pressure<40 mmHg or rest pain due to arterial ischemia. Main Outcome Measures: The primary outcome measure was Absolute Claudication Distance (ACD) while walking on a treadmill. Secondary outcome measures included Initial Claudication Distance (ICD), walk time measured in minutes, and a modified version of the Walking Impairment Questionnaire (WIQ). Results: There was no significant difference in ACD (mean difference: 14.1 m; 95% CI: -31.6 m-59.9 m; p=0.53) or ICD (mean difference: 5.9 m; 95% CI: -26.3 m-14.5 m; p=0.55) between active and sham devices. Mean walk time was identical between active and sham devices (5.6 minutes (2.1) vs. 5.6 minutes (2.0); p=0.99). The modified WIQ score was higher in the active group compared with the sham group (mean difference 2.1 m; 95% CI: 0.3 m-3.9 m; p=0.03). Conclusion: In patients with moderate to severe intermittent claudication, the Venowave device did not increase walking distance when used immediately prior to and during measured effort. This is the first study to use a sham device as a comparator in this specific context.