Based on the findings of a multicentre, randomised controlled trial, researchers have concluded that a new iliac vein stent—the Venastent (Tianhong)—provides a “safe and effective” endovascular treatment option for non-thrombotic iliac vein lesions (NIVLs) and is “as efficient as” the Zilver Vena stent (Cook Medical). The results of the trial also show that the Venastent significantly reduced symptoms of chronic venous disease.
The study, authored by Lei Hong, Xiaotian Wang (both The First Affiliated Hospital of USTC, Anhui, China) and colleagues, was recently published as an Editor’s Choice paper in the European Journal of Vascular and Endovascular Surgery (EJVES).
The authors explain that the Venastent is a self-expanding, bare stent system made with nickel titanium alloy and a conveying system. Some design elements of the Venastent were recently altered in order to improve its patency rate and intraoperative manipulation, they write. These modifications include the fact that the head of the stent is designed with a large mesh corolla, which extends into the contralateral canal wall, in order to avoid stent displacement. The large mesh ensures outflow of the contralateral iliac vessels, the investigators claim.
In order to begin their assessment of the patency and efficacy of the Venastent, the researchers note that they recruited 256 NIVL patients at 19 Chinese hospitals in the period October 2018 to January 2021. They subsequently conducted a randomised controlled trial to compare the Venastent with the Zilver Vena. The investigators randomly allocated all patients to two groups: the experimental group patients used Venastent, while the control group received the Zilver Vena.
Writing in EJVES, Hong, Wang et al report that they were able to collect a full set of data for a total of 123 patients in the experimental group and 122 patients in the control group. They relay a technical success rate of 100% (n=245/245). In the experimental group, they add, the patency rate was 100% (n=123/123), compared to a rate of 98.4% (n=120/122) in the control group one year after operation.
Hong, Wang and colleagues list a series of other findings in their paper. They report the following:
- The lower extremity swelling remission rate was 79.1% (n=87/110) in the experimental group and 78.4% (n=91/116) in the control group
- The lower extremity pain relief rate was 68.8% (n=50/80) in the experimental group and 77.2% (n=71/92) in the control group
- The ulcer healing rate was 90% (n=18/20) in the experimental group and 87% (n=20/23) in the control group
- There was no difference in stent restenosis or clinical remission between the two groups.
Hong, Wang et al acknowledge certain limitations of their study, including the fact that the follow-up time was just one year. The researchers plan to conduct follow-up at three and five years to evaluate the long-term efficacy of the Venastent in future research, they reveal in EJVES. They also recognise a second limitation as being the absence of medical management as another control group, and finally note that, as intravascular ultrasound (IVUS) is not yet widespread in China, they had to instead use 3D venography or computed tomography venography to detect vascular stenosis.