Interventional treatment for post-thrombotic chronic venous obstruction: Progress and challenges

Chronic venous obstruction, including nonthrombotic iliac vein lesions and post-thrombotic syndrome, presents a significant burden on patients' quality of life and health care systems. Venous recanalization and stenting have emerged as promising minimally invasive approaches, yet challenges in patient selection, procedural techniques, and long-term outcomes persist. This review synthesizes current knowledge on the interventional treatment of post-thrombotic syndrome, focusing on the evolution of endovascular techniques and stenting. Patient selection criteria, procedural details, and the characteristics of dedicated venous stents are discussed. Particular emphasis is given to the role of inflow and other anatomical considerations, along with postoperative management protocols for an optimal long-term outcome.

Optimizing Venous Stenting: Consensus Recommendations for Enhanced Management of Lower Extremity Deep Vein Thrombosis

INTRODUCTION

 Deep vein thrombosis (DVT) poses a complex challenge and often leads to postthrombotic syndrome (PTS), a debilitating complication. The emergence of venous stents offers a potential preventive avenue against this complication. This study aimed to provide consensus recommendations on the use of venous stent for DVT.

MATERIALS AND METHODS

 From June to July 2023, 20 internal medicine, angiology and vascular surgery, and vascular and interventional radiology experts were involved in the Delphi process. Thirty-one recommendations, categorized into three thematic areas, were rigorously evaluated: indications for stent use, stent selection and placement, and monitoring and prevention of complications. Agreement was evaluated using a Likert scale, with consensus defined as agreement by two-thirds of the participants.

RESULTS

 Consensus was reached for 23 (74.2%) of 31 recommendations. The agreement was centered on considerations, such as stent placement in specific acute DVT scenarios, emphasizing pivotal stent characteristics. However, there were divergences in the recommended stent length to prevent migration and stent characteristics based on iliocaval bifurcation morphology. Notably, there was no consensus on whether patients with DVT caused by a major transient risk factor need more than 3 months of anticoagulation therapy or whether aspirin should be added to anticoagulant treatment after venous stenting.

CONCLUSIONS

 These consensus recommendations offer practical insights into optimizing venous stent use to prevent PTS in DVT patients. Addressing the critical aspects of stent selection, placement, and postprocedural care, these recommendations contribute to clinical decision-making. The identified divergences underscore the importance of consensus and thus indicate the need for further investigation.

The TOPOS study

Background: We aimed to study the long-term safety and efficacy of oblique venous stents for post-thrombotic syndrome (PTS) with iliac vein compression. Patients and methods: In the multinational, prospective, single-arm TOPOS study, PTS patients scheduled for endovascular therapy with the sinus-Obliquus® stent and optional distal extension with the sinus-Venous® or sinus-XL Flex® stent were enrolled at eight European vascular centres between October 2016 and December 2020. The primary outcome was primary stent patency at 24 months, and secondary outcomes included the clinical course of PTS (Villalta score, revised Venous Clinical Severity Score [rVCSS], Visual Analog Scale [VAS] of pain), quality of life changes (Chronic Venous Insufficiency Quality of Life Questionnaire, CIVIQ-20), and device-related complications. Results: We enrolled 60 patients (mean age 46±15 years, 68% women, 13% active ulcers): 80% required stent extension (70% below the inguinal ligament). The primary patency rate at 24 months was 80.7% (95%CI 68.1-90.0%); it was higher in patients without vs. those with stent extension (90.9% vs. 78.3%, p=.01). Compared to baseline, the Villalta, rVCSS, pain VAS, and CIVIQ-20 decreased by a median of 8 (interquartile range (IQR): 4-11), 5 (IQR: 3-7), 3 (IQR: 2-5), and 17 (IQR: 6-22) points, respectively; p<.001 for all parameters. Overall, 9 events of acute stent occlusion, 4 symptomatic stent stenosis, and 1 pulmonary embolism occurred. We did not observe major bleeding events or contralateral thrombosis. Conclusions: Endovascular treatment with the oblique stent and optional stent extension was safe and resulted in high patency rates at 24 months. The reduction in PTS severity was substantial and persisted over 2-year follow-up.

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

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.

Deep venous thrombosis of the contralateral iliac vein after stenting of the iliocaval confluence: a therapeutic challenge

The treatment of choice for patients with symptomatic venous compression syndrome is venous stenting. However, this treatment has well-documented complications and, although rare, contralateral deep venous thrombosis is one of these complications. Our objective is to present a case of deep venous thrombosis of the contralateral iliac vein resulting from placement of the stent beyond the recommended position and the therapeutic challenge is to recanalize the vein with reconstruction of the iliocaval confluence.

Clinical outcomes of venous self-expanding stent placement for iliofemoral venous outflow obstruction

OBJECTIVE

In the present study, we evaluated the feasibility of a self-expanding venous stent for treating iliofemoral venous obstruction.

METHODS

The present retrospective study reviewed the data from 49 patients who had undergone Zilver Vena (Cook Medical, Bloomington, Ind) stent placement for treatment of iliofemoral venous obstruction from September 2017 to March 2019. All patients had undergone received follow-up duplex ultrasound examinations to assess for stent patency. The Villalta scores and Venous Clinical Severity Scores (VCSSs) were also calculated to stratify the postoperative improvement in disease.

RESULTS

Of the 49 patients, 19 had had acute deep vein thrombosis, 7, nonthrombotic iliac venous lesions, and 23, post-thrombotic syndrome. At 1 year after Zilver Vena stent placement, the primary, assisted primary, and secondary patency rates were 93.8%, 95.9%, and 97.9%, respectively. The baseline median Villalta score before treatment for those with post-thrombotic syndrome was 19 (range, 11-30), and the median VCSS for the patients with post-thrombotic syndrome and nonthrombotic iliac venous lesions was 11 (range, 6-25). At 1 year after stent placement, the median Villalta score for the post-thrombotic syndrome patients was 4.0 (range, 2-18), and the median VCSS for the post-thrombotic syndrome and nonthrombotic iliac venous lesions patients was 3.0 (range, 2-12).

CONCLUSIONS

Venous placement of self-expanding stents offers excellent 1-year patency rates and improved the outcomes of patients with iliofemoral venous obstruction caused by acute deep vein thrombosis, nonthrombotic iliac venous lesions, and post-thrombotic syndrome.

Catheter Interventions for Acute Deep Venous Thrombosis: Who, When and How

Deep venous thrombosis (DVT) is common and can be a source of morbidity by way of pulmonary embolism and post-thrombotic syndrome. Recent trials have demonstrated both early and late symptomatic benefit in venous thrombolysis and early recanalisation of the iliocaval system of selected patients. Based on the emerging evidence, national societies have published guidelines that recommend early thrombus removal in iliofemoral DVT in patients with low bleeding risk and good life expectancy. In light of these recommendations, endovenous thrombolysis and/or thrombectomy have become more popular among vein specialists. As more venous technology becomes available, surgeons and interventionalists should take pause and ensure their patient selection and treatment algorithms parallel that of existing and emerging evidence. This article summarises current evidence, technology, and the approach used at a high-volume academic centre in treating iliofemoral DVT.