The primary safety endpoint for this study will be a composite endpoint of any major adverse event (MAE) within 30 days, as adjudicated by a Clinical Events Committee.

For the pivotal cohort, one subject never returned for follow-up after discharge.

The primary effectiveness endpoint is the primary patency rate at 12 months post-intervention, defined as freedom from occlusion by thrombosis, freedom from surgical or endovascular intervention on target vessel which are found to have re-stenosis or stent occlusion to maintain patency, and freedom from in-stent stenosis more than 50% by venogram.

For the feasibility cohort, month 12 outcomes were available for 22 subjects. For the pivotal cohort, month 12 outcomes were available for 125 subjects. Those without venography performed at 12 months had their result assigned by random selection from subjects with a venogram result who had the same anatomy and the same DUS outcome (if available).

The secondary effectiveness endpoint for this study will be a binary response variable based on an improvement in Venous Clinical Severity Score (VCSS) by at least 50% at 12 months post-intervention. VCSS measures 10 clinical attributes of venous disease (Pain, Varicose Veins, Venous Edema, Skin Pigmentation, Inflammation, Induration, No. Active Ulcers, Active Ulcer Size, Ulcer Duration and Compression Therapy) on a scale of 0 - 3 (Absent 0, Mild 1, Moderate 2, and Severe 3).

For the feasibility cohort, 7 subjects did not have VCSS results at both month 12 and baseline. For the pivotal cohort, results for 24 subjects from a single US center are not included due to data integrity issues and 14 subjects did not have VCSS results at both month 12 and Baseline.

Procedural technical success is achievement of a final residual target vessel diameter stenosis of ≤50% as measured on the post procedural venogram, without skipped lesion regions, with placement of the study device alone with or without post-stenting balloon dilation as needed.

For the pivotal cohort, four subjects did not have the post-procedural venogram available for assessment. Additionally, there were two subjects that failed the endpoint due to two investigators using non-study stents.

Lesion success is defined as achievement of ≤50% residual diameter stenosis of the target lesion using any percutaneous method (including the use of non-study devices).

For the pivotal cohort, four subjects did not have the post-procedural veogram available for assessment.

Procedural success is defined as procedural technical success without the occurrence of a major adverse event (MAE) between the index procedure and discharge.

For the pivotal cohort, four subjects did not have the post-procedural venogram available for assessment.

Late technical success (through 12 months) is the absence of device movement >10mm related to anatomical landmarks or any migration leading to symptoms or requiring therapy; absence of stent occlusion by thrombosis or restenosis, defined as reduction in treated segment lumen more than 50% from the post-procedure vessel lumen diameter as measured by post-procedural venogram or DUS and maintenance of structural integrity, defined as the absence of pinching (focal compression), kinking (stent doubling or bending upon itself) that results in >50% diameter reduction of the stent, recoil (poor radial resistive force) or absence of fractures .

For the feasibility cohort, month 12 outcomes were available for 22 subjects. For the pivotal cohort, only 127 subjects had a 12-month venogram and/or stent fracture assessment.

The overall change in CIVIQ2 scores for the study patients, calculated using the mean scores at baseline and 12-months. This instrument is scored from 20 to 100 points with lower scores indicating a lesser impact on health.

For the feasibility cohort, three subjects did not have Month 12 CIVIQ-2 results. For the pivotal cohort, results for 24 subjects from a single US center are not included due to data integrity issues. Also, 11 subjects did not have a Month 12 visit and 2 subjects did not complete the CIVIQ forms.

Primary-assisted patency is defined as freedom from occlusion regardless of whether an intervention (subsequent to the index procedure) was performed.

For the feasibility cohort, only 21 subjects had known outcomes. For the pivotal cohort, only 126 subjects had known outcomes.

Secondary patency is defined as freedom from "permanent" loss of patency determined through last follow-up (irrespective of the number of interventions).

For the feasibility cohort, 13 subjects had known outcomes. For the pivotal cohort, 97 subjects had known outcomes.