Pivotal Evaluation of Novel Dedicated Venous Stent for Iliofemoral Venous Obstruction: A Prospective Cohort Study

Abstract

Purpose:

The purpose was to evaluate the clinical outcomes of a dedicated venous stent with the tripartite composite segments for the treatment of iliofemoral venous obstruction (IVO) in a mixed cohort of nonthrombotic iliac vein lesion (NIVL) and post-thrombotic syndrome (PTS) over a period of 12 months.

Methods:

The Grency Trial is a prospective, multicenter, single-arm, open-label, pivotal study, which was conducted at 18 large tertiary hospitals in China from August 2019 to October 2020. A total of 133 hospitalized patients were screened and 110 patients with clinical, etiology, anatomical, and pathophysiology clinical class (CEAP) clinical grade C>3 and iliac vein stenosis >50% or occlusion, including 72 patients with NIVL and 38 patients with PTS, were implanted with Grency venous stents. Primary endpoint was stent patency at 12 months follow-up, and secondary outcomes were technical success; improvement in venous clinical severity score (VCSS) at 3, 6, and 12 month follow-up; and rates of clinical adverse events.

Results:

Among 110 patients who were implanted with Grency venous stents, 107 patients completed the 12 month follow-up. All 129 stents were successfully implanted in 110 limbs. Twelve-month primary patency rate was 94.39% [95% confidence interval [CI]=88.19%-97.91%] overall, and 100% [94.94%-100%] and 83.33% [67.19%-93.63%] in the NIVL and PTS subgroups, respectively. Venous clinical severity score after iliac vein stenting improved significantly up to 12 months follow-up. There were 3 early major adverse events (1 intracerebral hemorrhage and 2 stent thrombosis events related to anticoagulation therapy), and 7 late major adverse events (1 cardiovascular death, 1 intracranial hemorrhage with uncontrolled hypertension, and 5 in-stent restenosis cases without stent fractures or migration).

Conclusions:

The Grency venous stent system appeared excellent preliminary safe and effective for IVO treatment. Further large-scale studies with longer-term follow-up are needed to evaluate long-term patency and durability of stent.

Clinical impact

The design of venous stents for iliofemoral venous obstruction (IVO) must address engineering challenges distinct from those encountered in arterial stenting. The Grency venous stent, a nitinol self-expanding stent specifically tailored for IVO, features a composite structure designed to meet the stent requirements of various iliac vein segments. The Grency Trial is a prospective, multicenter, single-arm, open-label pivotal study aimed at evaluating the efficacy and safety of the Grency stent system. Following a 12-month follow-up period, the Grency venous stent system has demonstrated both safety and efficacy in treating iliofemoral venous outflow obstruction.

Keywords

venous stent self-expanding stent iliofemoral venous obstruction

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References

Liu

The preclinical study of a novel self-expanding dedicated venous stent based on human CT image data: (DOI:10.27637/d.cnki.gjyjc.2019.000082) [Doctoral dissertation, Chinese PLA Medical School]. Chinese Doctoral Dissertations Full-text Database, 2020. https://oversea.cnki.net/.

Raju

Treatment of iliac-caval outflow obstruction. Semin Vasc Surg. 2015;28(1):47–53.

Riegger

Byrne

Joner

, et al. Histopathological evaluation of thrombus in patients presenting with stent thrombosis— a multicenter European study: a report of the prevention of late stent thrombosis by an interdisciplinary global European effort consortium. Eur Hea J. 2016;37(19):1538–1549.

Lichtenberg

Breuckmann

Stahlhoff

, et al. Placement of closed-cell designed venous stents in a mixed cohort of patients with chronic venous outflow obstructions: short-term safety, patency, and clinical outcomes. Vasa. 2018;47(6):475–481.

O’Sullivan

Sheehan

Lohan

, et al. Iliofemoral venous stenting extending into the femoral region: initial clinical experience with the purpose-designed Zilver Vena stent. J Cardiovasc Surg (Torino). 2013;54(2):255–261.

Razavi

Marston

Black

, et al. The initial report on 1-year outcomes of the feasibility study of the VENITI VICI VENOUS STENT in symptomatic iliofemoral venous obstruction. J Vasc Surg Venous Lymphat Disord. 2018;6(2):192–200.

van Vuuren

TMAJ

Doganci

Wittens

CHA.

Patency rates and clinical outcomes in a cohort of 200 patients treated with a dedicated venous stent. J Vasc Surg Venous Lymphat Disord. 2018;6(3):321–329.

Lichtenberg

MKW

de Graaf

Stahlhoff

, et al. Venovo venous stent in the treatment of non-thrombotic or post-thrombotic iliac vein lesions: short-term results from the Arnsberg venous registry. VASA Zeitschr Gefasskrankh. 2019;48(2):175–180.

Henke

Sharma

Wakefield

, et al. Insights from experimental post-thrombotic syndrome and potential for novel therapies. Transl Res. 2020;225:95–104.

10.

Neglén

Hollis

Olivier

, et al. Stenting of the venous outflow in chronic venous disease: long-term stent-related outcome, clinical, and hemodynamic result. J Vasc Surg. 2007;46(5):979–990.

11.

Zhang

Jing

Sang

, et al. Long-term follow-up of the stenting across the iliocaval confluence in patients with iliac venous lesions. J Throm Thrombol. 2019;47(1):134–139.

12.

Raju

Neglen

Percutaneous recanalization of total occlusions of the iliac vein. J Vasc Surg. 2009;50(2):360–368.

13.

Duarte-Gamas

Rocha-Neves

Pereira-Neves

, et al. Contralateral deep vein thrombosis after stenting across the iliocaval confluence in chronic venous disease: a systematic review. Phlebology. 2020;35(4):221–230.

14.

Yang

Zhao

Chen

, et al. The effect of stent compression on in-stent restenosis and clinical outcomes in iliac vein compression syndrome. Quant Imaging Med Surg. 2021;11(6):2245–2252.

15.

Raju

Tackett

Jr Neglen

Reinterventions for nonocclusive iliofemoral venous stent malfunctions. J Vasc Surg. 2009;49(2):511–518.

16.

Murphy

Johns

Varney

, et al. Deep venous thrombosis associated with caval extension of iliac stents. J Vasc Surg Venous Lymphat Disord. 2017;5(1):8–17.

17.

Raju

Davis

Anomalous features of iliac vein stenosis that affect diagnosis and treatment. J Vasc Surg Venous Lymphat Disord. 2014;2(3):260–267.

18.

Cho

Kim

Hong

, et al. Stent compression in iliac vein compression syndrome associated with acute ilio-femoral deep vein thrombosis. Korean J Radiol. 2015;16(4):723–728.