A Systematic Review and Meta-Analysis of 12-Month Patency After Intervention for Iliofemoral Obstruction Using Dedicated or Non-Dedicated Venous Stents

Background: Endovascular stenting of the deep venous system has been proposed as a method to treat patients with symptomatic iliofemoral outflow obstruction. The purpose of this systematic review and meta-analysis was to compare the effectiveness of this treatment at 1-year following the development of dedicated venous stents. Method and results: We searched MEDLINE and EMBASE for studies evaluating the effectiveness of venous stent placement. Data were extracted by disease pathogenesis: non-thrombotic iliac vein lesions (NIVL), acute thrombotic (DVT), or post-thrombotic syndrome (PTS). Main outcomes included technical success, stent patency at 1 year and symptom relief. A total of 49 studies reporting outcomes in 5154 patients (NIVL, 1431; DVT, 950; PTS, 2773) were included in the meta-analysis. Technical success rates were comparable among groups (97%-100%). There were no periprocedural deaths. Minor bleeding was reported in up to 5% of patients and major bleeding in 0.5% upon intervention. Transient back pain was noted in 55% of PTS patients following intervention. There was significant heterogeneity between studies reporting outcomes in PTS patients. Primary and cumulative patency at 1 year was: NIVL—96% and 100%; DVT—91% and 97%; PTS (stents above the ligament)—77% and 94%, and; PTS (stents across the ligament)—78% and 94%. There were insufficient data to compare patency outcomes of dedicated and nondedicated venous stents in patients with acute DVT. In NIVL and PTS patients, stent patency was comparable at 1 year. There was inconsistency in the use of validated tools for the measurement of symptoms before and after intervention. When reported, venous claudication, improved in 83% of PTS patients and 90% of NIVL patients, and ulcer healing occurred in 80% of PTS patients and 32% of NIVL patients. Conclusions: The first generation of dedicated venous stents perform comparably in terms of patency and clinical outcomes to non-dedicated technologies at 1 year for the treatment of patients with NIVL and PTS. However, significant heterogeneity exists between studies and standardized criteria are urgently needed to report outcomes in patients undergoing deep venous stenting.

Stenting in the common femoral vein does not increase posthrombotic syndrome or rethrombosis

Background In lower limbs deep venous thrombosis (DVT) scenario there is evidence that favours catheter guided invasive treatment. The treatment with stenting in the common femoral vein could be related with a diminished permeability in the inflow of the deep femoral vein. There is scarce data of the clinical follow up of this treatment. Purpose To analize and compare clinical and procedural outcomes in endovenous interventions that required stent placement in the common femoral vein because of residual lesion vs interventions that did no require such treatment. Methods From May 2010 to December 2020, 122 endovenous interventions were performed, within these 74 were DVT compromising the iliofemoral territory. Two groups were defined: Group A 28 (38%) that required stent placement in the common femoral vein and Group B 46 (62%) that did not required such treatment. Results Baseline characteristics were Group A vs Group B n (%) respectively: Median age 41.1±16.7 vs 40.5±18.8; female 23 (82) vs 27 (58); smoking 7 (25) vs 14 (30); cancer 1 (4) vs 7 (15); prior prolonged rest 7 (25) vs 14 (30); concomitant diagnosis of pulmonary embolism 7 (25) vs 17 (37). Within the female population 2 (7) vs 1 (2) were in puerperium; 6 (21) vs 6 (13) were under contraceptive therapy. Regarding the diagnosis of DVT 21 (75) vs 37 (80) were acute; 7 (25) vs 9 (19) were chronic. Compromised vessels were primitive iliac vein 21 (75) vs 38 (82); external iliac vein 6 (21) vs 18 (39); superficial femoral vein 11 (39) vs 8 (17); May-Thurner syndrome 14 (50) vs 20 (43). As regards the aspects of the intervention 15 (53) vs 34 (74) had a filter implanted in the inferior vena cava; thrombolytics were infused in 20 (71) vs 32 (70); manual thrombectomy was performed in 8 (27) vs 17 (37); mechanical thrombectomy 11 (39) vs 19 (41); pre dilation with balloon was performed in 22 (79) vs 39 (85); dedicated venous stents were implanted in 22 (78) vs 39 (85); not dedicated venous stents in 13 (46) vs 11 (24). Technique success was achieved in 28 (100) vs 45 (98) p=1; major bleeding occurred 0 vs 2 (4) p=0.5; rethrombosis 3 (10) vs 9 (20) p=0.25; intrahospital death 1 (4) vs 2 (4) p=1; early reintervention was needed 1 (4) vs 2 (4) p=1, radiation dose (min) 35.4±20.2 vs 30.1±17.0 p=0.2; Contrast (ml) 216.5±76.8 vs 217.3±90.8 p=0.9. During follow up (34.1±31.5 vs 22.3±16.4) image control was performed in 27 (96) vs 39 (85) p=0.23 with either doppler or chest computed tomography angiography. Post thrombotic syndrome (PTS) symptoms were classified with Villalta Score assuming that 0–4 points had no PTS, 5–9 points presented mild PTS, 10–14 points moderate PTS, >14 points severe PTS, in Group A 1 (4) presented mild PTS vs Group B 2 (4) mild PTS p=1, 1 (2) moderate PTS. Conclusions Endovenous treatment with stent placement in the common femoral vein did not required more reinterventions nor had more complications nor had more PTS that the interventions without stent placement. FUNDunding Acknowledgement Type of funding sources: None. Table 1. Basal Characteristics Table 2. Outcomes

What are the ideal characteristics of a venous stent?

Historically, the stents used in the venous system were not dedicated scaffolds. They were largely adapted arterial stents. An essential feature of a venous stent is compliance, in order to adapt its crosssectional area to the vein. It should also be crush resistant, corrosion resistant and fatigue resistant. The material should be radiopaque, for follow-up. Another characteristic of the ideal venous stent is flexibility, to adapt its shape to the vein, not vice versa. The scaffold should be uncovered too, in order to avoid the occlusion of collaterals. The ideal venous stent should not migrate, so it is necessary a large diameter and a long length. The radial force is important to prevent migration. However, current stents derived from arterial use display high radial force, which could affect the patency of the thin venous wall. Alternatively, if the stent has an anchor point, that permits a passive anchoring, the radial force required to avoid migration will be lower. Dedicated venous stents were not available until very recently. Furthermore, there is a preclinical study about a new compliant nitinol stent, denominated Petalo CVS. Out of the commonest causes of large veins obstruction, dedicated venous stent could also treat other diseases described more recently, such as the jugular variant of the Eagle syndrome, JEDI syndrome and jugular lesions of the chronic cerebrospinal venous insufficiency that result unfavorable for angioplasty according to Giaquinta classification.

Choosing the Most Appropriate Treatment Option for Pelvic Venous Disease: Stenting versus Embolization

Pelvic venous disease (PeVD) in women encompasses a wide variety of entities all resulting in pelvic pain and varices. Successful treatment with percutaneous interventions is dependent on identifying underlying factors contributing to the disease and addressing them with either embolization of incompetent veins or stenting for venous stenoses. There are a multitude of embolization methods with marked practice heterogeneity. Moreover, with the ongoing development of dedicated venous stents in the treatment of chronic venous disease, there are more opportunities to consider this modality for the treatment of PeVD, as many patients present with combined vein reflux and central venous stenosis. The necessity to address both and the order of interventions in these patients is still to be elucidated. Here, we describe when to choose stenting or embolization for PeVD, their limitations, and our practice and identify further areas of research in this field.