Non-thrombotic Iliac Vein Lesions Research Articles

Left common iliac vein diameter in patients referred for lower limb venous duplex ultrasound.

Evidence regarding ultrasound assessment of left common iliac vein diameter (LCIV) is limited. Extensive work is currently being undertaken worldwide on non-thrombotic iliac vein lesions to identify patients who may benefit from intervention to alleviate symptoms of chronic venous obstruction. Interventions include long-term stent implantation to improve vein diameter stenosis. This study aimed to assess a cohort of symptomatic venous patients and the diameter of the LCIV in these patients. : Retrospective medical records review of all patients attending a tertiary vascular surgery centre who underwent a venous duplex ultrasound assessment between April 2017 and February 2018 were analysed for assessment of LCIV. Medical records of those patients with documented LCIV diameter were assessed over 18 months of follow-up. : A total of 672 (271 males, 401 females) LCIV diameter measurements were collected. The age of the patients ranged from 21 to 95years (mean = 56.38). Median LCIV diameter overall was 7.64mm (IQR 5.80mm-9.00mm). 40 patients (6%) were reported to have a LCIV diameter measurement of < 4mm, 8 (20%) male and 32 female (80%). 17 of these 40 patients (47.5%) were treated conservatively. Median LCIV diameter was 3.4mm (IQR 2.5-3.7). 21 of these 40 patients (52.5%) underwent superficial venous intervention only, with a median LCIV diameter of 3.5mm (IQR 3.2-3.7) and 2 out of these 40 patients (5%) underwent deep venous stenting (2/2 female - 100%), with a median LCIV diameter of 2.9 (IQR 2.9-2.9). No patients underwent both superficial and deep venous treatment in this 40 patient cohort. In those undergoing superficial venous intervention, 4 (19%) underwent repeat treatment. The two deep venous stenting patients underwent magnetic resonance venogram and venogram with intravascular ultrasound to allow stent placement, which confirmed a narrowed left common iliac vein. Primary stent patency at 18 months was 100%. In this large study cohort of venous duplex assessments the median vein diameter was 7.64mm and 40 patients out of 672 had a vein diameter smaller than 4mm. 2 patients underwent deep venous stenting with primary patency of 100%.

Predictive Factors of Stent Patency in Iliofemoral Venous Diseases in a Multicentre Cohort Study

To assess predictive factors of primary stent patency in three groups of patients with history of lower limb (LL) vein thrombosis: non-thrombotic iliac vein lesion (NIVL), acute deep vein thrombosis (aDVT) and post thrombotic syndrome (PTS). Consecutive patients with history of LL vein stenting from 7 hospitals were included from January 2014 to December 2020. All patients received an iliac or common femoral venous stent and had at least a 6-month follow-up available with stent imaging. The anticoagulant and antiplatelet therapy strategies employed after venous stenting are reported and compared between groups. This study included 377 patients: 134 NIVL, 55 aDVT and 188 PTS. Primary patency was significantly higher in the NIVL group (99.3%) compared to the PTS group (68.6%) (p <.001) and the aDVT group (83.6%) (p=.002). PTS patients received a significantly greater number of stents (p<.001) and had more stents below the inguinal ligament (p<.001). Median follow-up was 28.8 months [IQR: 16; 47]. Discontinuation of antiplatelet therapy at the last assessment was 83.6% for NIVL, 100% for aDVT and 95.7% for the PTS group (p<.001). Discontinuation of anticoagulation therapy at the last assessment was 93.2% for NIVL, 25.0% for aDVT and 70.3% for the PTS group (p<.001). The only predictor of worse primary patency in the aDVT group was long-term anticoagulation before stenting. Patients with NIVL have better primary patency after venous stenting than patients with venous thrombotic disorders. Long-term anticoagulation before stenting was the only factor associated with poorer primary patency in patient with aDVT.

Iliac vein stent failure in community practice and results of corrective reinterventions

ObjectiveThe goal of endovenous stenting is to relieve venous obstruction and reduce peripheral venous hypertension by using large caliber venous stents in the presence of adequate venous inflow and outflow for the stented conduit. The aim of this report is to describe the technical reasons and outcomes for reinterventions in a subset of patients who had a history of iliac vein stenting and were now referred to us at a specialty venous clinic for further care. MethodsFrom January 2016 to December 2021, records of all patients who were referred to us with a history of iliac vein stenting performed at an outside facility and who had a reoperation performed at our center were retrospectively analyzed. ResultsA total of 149 limbs underwent a deep venous reintervention after a failure of a trial of conservative therapy. The mean age of the sample was 57 ± 16 years. The ratio of non-thrombotic iliac vein lesions to post-thrombotic lesions was 1:2.5. The majority of the patients (84%) were CEAP class C4 or higher. The most common reason for reintervention was stent occlusion (74%), followed by iatrogenic stenosis (53%) and in-stent restenosis/shelving (38%). There was a trend for improvement in all clinical parameters (venous clinical severity score, visual analog scale for pain, and edema grade) after the reintervention. Poor inflow was present in 70% of limbs with stent occlusion. The median diameters of stented common femoral vein, external iliac vein, and common iliac vein prior to reintervention were 12, 12, and 13 mm, respectively. The median diameters of stented common femoral vein, external iliac vein, and common iliac vein after reintervention were 14, 15, and 16 mm, respectively. Eighty-eight percent of limbs required at least one further reintervention after initial reoperation. ConclusionsVenous reoperations are generally infrequent and required in a small number of patients. Poor inflow appeared to be a common cause of stent occlusion. Iatrogenic stenosis is another common reason for venous reoperation and is difficult to fully rectify through current endovascular techniques and tools. Use of intravascular ultrasound planimetry routinely in every deep venous intervention and thorough knowledge of the principles of venous stenting outlined in this report may help forestall the need for reoperative deep venous surgery in some cases.

Venous stent patency is independent of total stented length in nonthrombotic iliac vein and post-thrombotic venous stenoses

ObjectiveVenous stenting has become the preferred treatment of symptomatic outflow obstruction due to nonthrombotic iliac vein lesions (NIVLs) and post-thrombotic venous stenoses (PTs). A paucity of data exists regarding the effect of stent length on patency rates after intervention. We evaluated the association between stent length and patency in patients treated for iliofemoral venous outflow obstruction. MethodsThe institutional review board approved the present study. A total of 161 patients had undergone venous stenting for NIVLs and thrombotic disease from January 2016 to April 2021. For thrombotic disease, patients with PTs and those with acute deep vein thrombosis (DVT) with underlying outflow obstruction were included. The patient characteristics evaluated included gender, age, body mass index, diagnosed thrombophilia, a history of venous thromboembolism, and CEAP (clinical, etiologic, anatomic, pathophysiologic) score. All the patients had undergone multiplanar venography and intravascular ultrasound during the index procedure. The intravascular ultrasound findings were used to determine the diameter and length of the implanted stents. The patients were placed into two groups, those with stented lengths ≤100 mm and those with stented lengths >100 mm. The primary end point was stent patency between the two groups using duplex ultrasound at 6 months. ResultsA total of 108 patients (58.3% female) had had 6-month duplex ultrasound scans available for review. Their mean age was 55.6 ± 17.2 years. The mean body mass index was 31.7 ± 6.9 kg/m2. Overall, the 6-month patency was 89.9%. Of the 108 patients, 56 (51.9%) had had a total stented length of ≤100 mm with a 6-month patency of 92.9%. The remaining 52 patients (48.1%) had had a total stented length >100 mm with a 6-month patency of 86.5%. The rate of patency did not differ significantly between the two groups (P = .222). Stent patency at 6 months for patients with NIVLs was 98% (40 of 41). Stent patency for patients with PTs was 84% (32 of 38). Patency for patients with acute DVT who had undergone stenting after thrombectomy was 86% (25 of 29). Overall, 10 patients with thrombotic disease, including PT and acute DVT, had developed stent thrombosis. The total stented length was not predictive of the loss of patency. ConclusionsThese findings suggest that the length of stent coverage does not confer an increased likelihood of stent thrombosis for patients with iliofemoral venous obstruction. Interventionalists should treat the affected venous segments identified on intravascular ultrasound and effectively stent from normal to normal venous areas, regardless of the stent length required. These results suggest that the total stented length is not a risk factor for stent thrombosis for both NIVL and thrombotic iliofemoral venous lesions.

How Prior History of Deep Vein Thrombosis Influences Iliac Vein Stenting

We observed that a history of deep vein thrombosis (DVT) was more prevalent than expected among patients undergoing iliofemoral vein stent placement for nonthrombotic iliac vein lesion (NIVL), of which May-Thurner syndrome is the most common. We undertook this study to understand how prior DVT affects perioperative outcomes among these patients.

Double-barrel iliocaval reconstruction using closed-cell dedicated venous stents

ObjectiveDouble-barrel iliocaval reconstruction is performed by deploying two stents simultaneously in a side-by-side, or “double-barrel,” configuration in the inferior vena cava (IVC) with extension into the bilateral common iliac veins. The aim of this study was to examine the outcomes of double-barrel reconstruction using closed-cell dedicated venous stents for the treatment of iliocaval deep venous thrombosis and iliac vein compression syndrome. MethodsAll endovascular procedural reports comprising vascular surgery and interventional radiology operators from a single urban academic hospital between May 1, 2019, and April 30, 2021, were retrospectively searched. A cohort of 22 consecutive patients who underwent double-barrel iliocaval stenting with closed-cell dedicated venous stents for chronic or acute-on-chronic iliocaval venous disease without prior endovascular iliocaval repair was identified. Baseline characteristics, procedural data, and patient outcomes were determined via a manual review of preprocedure clinical notes, diagnostic imaging studies, procedure notes and images, and follow-up clinical notes. ResultsThe median (range) age was 59 (27-81) years, and the cohort consisted of 59.1% female. The most common presenting symptoms of venous disease were lower extremity swelling (90.9%) and pain (50.0%). CEAP clinical classification was C3 in 86.4% of patients, whereas the remainder had C4 disease. Most patients (72.7%) had post-thrombotic syndrome, 22.7% had a nonthrombotic iliac vein lesion, and one patient (4.5%) had the congenital absence of the infrarenal IVC. A total of 40.9% of patients had a pre-existing IVC filter at the time of treatment. Six of the 22 patients underwent concurrent pharmacomechanical thrombectomy during the index iliocaval reconstruction and stenting procedure. The number of stents placed ranged from 2 to 5. With a mean follow-up period of 7.1 months, ranging from 12 days to 16.7 months, the freedom from reintervention rate was 90.9%. Twenty of 22 patients achieved subjective improvement or resolution of symptoms. The major adverse event rate was 9.1%, as two patients had access site complications requiring intervention. ConclusionsDouble-barrel iliocaval reconstruction with closed-cell dedicated venous stents for the treatment of post-thrombotic syndrome or iliac vein compression syndrome is technically feasible and clinically effective with a low reintervention rate.

Criteria to predict midterm outcome after stenting of chronic iliac vein obstructions (PROMISE trial)

BackgroundEndovenous stent placement has become a first-line approach to prevent post-thrombotic syndrome in patients with chronic post-thrombotic obstruction (PTO) or nonthrombotic iliac vein lesions if conservative management fails. This study aims to identify factors associated with loss of patency to facilitate patient selection for endovenous stenting. MethodsWe retrospectively analyzed 108 consecutive patients after successful endovenous stenting for chronic vein obstruction performed at a single institution from January 2008 to July 2020. Using multivariable logistic regression, we explored potential predictive factors for loss of stent patency, including baseline demographics, post-thrombotic changes, and peak flow velocities measured in the common femoral vein (CFV), deep femoral vein, and femoral vein (FV) using duplex ultrasound examination. ResultsThe mean follow-up duration was 41 ± 26 months, and participants had a mean age of 47.4 ± 15.4 years with 46.3% women. Ninety (83.3%) patients had PTO and 18 (16.7%) had nonthrombotic iliac vein lesions, predominantly due to May-Thurner syndrome. Loss of patency occurred in 20 (18.5%) patients, all treated for PTO. Comorbidities, side of intervention, and sex did not differ between patients with occluded and patent stents. Stent occlusion was more common with increasing number of stents implanted (P < .001) and with distal stent extension into and beyond the CFV (P < .001). Preinterventional predictive factors for stent occlusion were lower duplex ultrasound peak velocity in the CFV (odds ratio [OR]: 7.52, 95% confidence interval [CI]: 2.54-22.28; P < .001) and FV (OR: 10.75, 95% CI: 2.07-55.82; P < .005), and post-thrombotic changes in the deep femoral vein (OR: 4.51, 95% CI: 1.53-13.25; P = .006) and FV (OR: 3.62: 95% CI: 1.11-11.84; P = .033). Peak velocities of ≤7 cm/s (interquartile range: 0-20 cm/s) in the CVF and ≤8 cm/s (interquartile range: 5-10 cm/s) in the FV were significantly associated with loss of patency. ConclusionsInsufficient venous inflow as assessed by low peak velocities in the CFV and FV as well as post-thrombotic findings represent reliable risk predictors for stent occlusions, warranting their inclusion into the decision-making process for invasive treatment of PTO.

Clinical Efficacy of Venastent - A Novel Iliac Vein Stent for Non-Thrombotic Iliac Vein Lesions: A Multi-Centre Randomised Controlled Trial

To determine the efficacy of Venastent - a novel iliac vein stent for non-thrombotic iliac vein lesions (NIVLs). From October 2018 to January 2021, 256 NIVL patients were recruited at 19 Chinese hospitals. A randomised controlled trial was conducted to compare the efficacy of the new iliac vein stent-Venastent (Tianhong China) with Zilver stent (Cook USA). All patients were allocated randomly to two groups: the experimental group patients used Venastent, while the control group received the Zilver stent. The trial was registered in Chinese Clinical Trial Registry (ChiCTR2200057851). A total of 123 patients in the experimental group and 122 patients in the control group had a full set of data collected (p = ns). The technical success rate was 100% (n = 245/245). The patency rate was 100% (n = 123/123) in the experimental group and 98.4% (n = 120/122) in control group one year after operation (p = ns). 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 (p = ns). 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 (p = ns). The ulcer healing rate was 90% (n = 18/20) in the experimental group and 87% (n = 20/23) in the control group (p = ns). There was no difference in stent re-stenosis or clinical remission between the two groups. The new iliac vein stent, Venastent, had a comparable high patency rate and safety profile as the Zilver stent (Cook) in NIVLs patients. Venastent significantly reduced symptoms of chronic venous disease.

Treatment of Non-thrombotic Iliac Vein Stenosis: Where is the Evidence?

Non-thrombotic iliac vein lesions (NIVLs) refer to iliac vein lumen stenosis, usually secondary to extrinsic compression, without associated thrombosis. Clinical presentation varies; patients may be asymptomatic, have symptoms of lower extremity venous hypertension, or in women, may be associated with chronic pelvic pain. Given the significant variability in symptomatology, thorough history and physical examination are mandatory in excluding other causes of symptoms. Non-invasive imaging, such as venous duplex/insufficiency ultrasound examinations, and axial imaging aid in the diagnosis of a NIVL in the appropriate clinical context. Catheter venography and intravascular ultrasound remain the primary modalities for definitive diagnosis, treatment planning, and ultimately placement of self-expanding venous stents to resolve the causative iliofemoral venous obstruction. In appropriately selected patients, stent placement can lead to marked improvements in symptoms, heal stasis ulceration when present, and improve disease-specific and overall quality of life. Stents placed in patients with NIVL demonstrate high long-term primary patency. In this article, the authors discuss clinical presentation, diagnostic workup, endovascular interventions and outcomes of NIVL treatment.

Patients With Post-thrombotic Syndrome Are More Likely to Undergo Venographic Reintervention and Experience Slower Symptom Resolution After Iliac Vein Stenting

Patients undergoing iliac vein stent placement (IVS) for chronic proximal venous outflow obstruction are observed to have two types of stenosis: a more focal stenosis from external compression, also known as nonthrombotic iliac vein lesions (NIVL), or more diffuse stenosis suggestive of post-thrombotic syndrome (PTS) from a remote deep venous thrombosis (DVT). We assessed the influence of PTS on the outcomes of IVS.

Editor's Choice – Clinical Efficacy of Venastent - A Novel Iliac Vein Stent for Non-Thrombotic Iliac Vein Lesions: A Multi-Centre Randomised Controlled Trial

To determine the efficacy of Venastent - a novel iliac vein stent for non-thrombotic iliac vein lesions (NIVLs). From October 2018 to January 2021, 256 NIVL patients were recruited at 19 Chinese hospitals. A randomised controlled trial was conducted to compare the efficacy of the new iliac vein stent-Venastent (Tianhong China) with Zilver stent (Cook USA). All patients were allocated randomly to two groups: the experimental group patients used Venastent, while the control group received the Zilver stent. The trial was registered in Chinese Clinical Trial Registry (ChiCTR2200057851). A total of 123 patients in the experimental group and 122 patients in the control group had a full set of data collected (p= ns). The technical success rate was 100% (n= 245/245). The patency rate was 100% (n= 123/123) in the experimental group and 98.4% (n= 120/122) in control group one year after operation (p= ns). 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 (p= ns). 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 (p= ns). The ulcer healing rate was 90% (n= 18/20) in the experimental group and 87% (n= 20/23) in the control group (p= ns). There was no difference in stent re-stenosis or clinical remission between the two groups. The new iliac vein stent, Venastent, had a comparable high patency rate and safety profile as the Zilver stent (Cook) in NIVLs patients. Venastent significantly reduced symptoms of chronic venous disease.

Best Endovenous Treatment, Including Stenting, versus Best Nonendovenous Treatment in Chronic Proximal Deep Venous Disease—The BEST Multicenter Randomized Controlled Trial Protocol

Chronic obstruction of the iliac veins or inferior vena cava can occur as a result of deep vein thrombosis, or owing to extrinsic compression in nonthrombotic iliac vein lesions (NIVLs). This obstruction can manifest as post-thrombotic syndrome (PTS) after deep vein thrombosis or as chronic venous disease (CVD) in NIVL. Little evidence exists to support the use of deep venous stents in established PTS or NIVLs, and the evidence for its use in the prevention of PTS is inconclusive. A provisional health economic analysis over 5 years found that the incremental cost-effectiveness ratio of stenting versus no stenting over a 5-year period was between £7,500 and £52,000 per quality-adjusted life-year for treatment of established PTS.

Pivotal Study Evaluating the Safety and Effectiveness of the Abre Venous Self-Expanding Stent System in Patients With Symptomatic Iliofemoral Venous Outflow Obstruction.

Iliofemoral venous obstruction is recognized with increasing frequency as the underlying cause of lower extremity symptoms including edema, pain, skin changes, and, in advanced cases, ulceration. This study sought to evaluate the safety and effectiveness of the Abre venous self-expanding stent system for the treatment of symptomatic iliofemoral venous outflow obstruction. The ABRE Study (A Multi-Center, Non-Randomized Study to Evaluate the Safety and Effectiveness of the Abre Venous Self-Expanding Stent System in Patients With Symptomatic Iliofemoral Venous Outflow Obstruction) is a single-arm, multicenter, prospective study that included 200 subjects from 24 global sites. The primary end points were 12-month primary patency and major adverse events within 30 days. Secondary end points included lesion and procedure success, primary-assisted and secondary patency, major adverse events, stent migration, stent fracture, and quality of life changes. End point-related adverse events and imaging studies were adjudicated by independent clinical events committee and core laboratories, respectively. Venous obstruction cause was classified as acute deep vein thrombosis (16.5%, 33/200), post-thrombotic syndrome (47.5%, 95/200), or nonthrombotic iliac vein lesion (36.0%, 72/200). The common iliac and external iliac veins were stented in 96.0% (192/200), 80.5% (161/200) of subjects, respectively. Stent implant into the common femoral vein was required in 44.0% (88/200). Primary patency at 12 months was 88.0% (162/184). Four (2.0%) major adverse events occurred within 30 days. Twelve-month primary-assisted and secondary patency were 91.8% (169/184) and 92.9% (171/184), respectively. No stent fractures or migrations were reported. Mean target limb Villalta score decreased from 11.2±5.6 at baseline to 4.1±4.8 at 12 months, and the mean target limb revised Venous Clinical Severity Score decreased from 8.8±4.7 at baseline to 4.3±3.6 at 12 months. Clinically meaningful improvements in quality of life and venous functional assessment scores from baseline were demonstrated through 12 months in all measures. Symptomatic iliofemoral venous obstruction can be successfully treated with an Abre venous stent. Study outcomes demonstrated a high patency rate with a good safety profile. Patients demonstrated a significant reduction in clinical symptoms and improvement in quality of life that was maintained through 12-month follow-up. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03038438.

A systematic review of current trends in pharmacologic management after stent placement in nonthrombotic iliac vein lesions.

Stenting of the iliac vein is increasingly recognized as a treatment for chronic venous insufficiency (CVI). However, the pharmacologic management after stent placement is unclear. This review was conducted to illustrate recent trends in anticoagulation and antiplatelet regimens following stent placement for nonthrombotic iliac vein lesions (NIVL). The MEDLINE database was searched using the term "iliac vein stent." Retrieval of articles was limited to studies conducted on humans and published in English between 2010 and 2020. Studies were included that described iliac vein stent placement. Studies were excluded that contained fewer than 25 patients, performed procedures other than stent placement, did not specify the postoperative anticoagulant used, or treated lesions of thrombotic origin. 12 articles were included in this review, yielding a total of 2782 patients with a male-to-female ratio of 0.77. The predominant CEAP classification encountered was C3. The most common stent used in the included studies was the Wallstent (9/12), and the most common pharmacologic regimen was 3 months of clopidogrel (6/12). Warfarin, aspirin, cilostazol, and rivaroxaban were among other agents used. Primary stent patency ranged from 63.1 to 98.3%. There was no apparent correlation between pharmacologic agent used and stent patency or subjective patient outcomes. Multiple different approaches are being taken to pharmacologically manage patients following stent placement for NIVL. There is no consensus on which agent is best, nor is there a formal algorithmic approach for making this decision. Additionally, the findings in this study call into question whether anticoagulation following stenting for NIVL is necessary at all, given the similar outcomes among the different agents utilized. This review underscores the potential value of undertaking a multi-institutional prospective study to determine what is the best pharmacologic therapy following venous stent placement for NIVL.

Immediate postprocedure anticoagulation with factor Xa inhibitors of venous stents for nonthrombotic venous lesions does not increase stent patency

BackgroundMany clinicians will prescribe anticoagulation therapy for patients after iliac vein stenting to prevent early or late stent thrombosis. At present, it is unknown whether therapeutic anticoagulation has any effect on stent patency. Thus, we assessed the role of short-term anticoagulation on iliac vein stent patency in patients with nonthrombotic iliac vein lesions (NIVLs). MethodsWe performed a retrospective medical record review of all iliac vein stents placed for NIVLs at the Center for Vascular Medicine from January 2018 to December 2019. We compared the stent patency in the two groups. The anticoagulation (AC) group had received rivaroxaban or apixaban postoperatively for a minimum of 90 days and were compared with a group that had received no postoperative anticoagulation (NAC). Stent patency was assessed using transabdominal ultrasound at 3, 6, 12, 18, 24, and 30 months. At the discretion of the treating physician, the patients who demonstrated thrombus layering on surveillance ultrasound scanning continued rivaroxaban or apixaban until thrombus resolution was observed. The demographics and stent location, diameter, and length were assessed. Stent patency was analyzed using life table analyses. Differences in stent patency were analyzed using GraphPad Prism, version 8, statistical software (GraphPad Software Inc, La Jolla, Calif) and the log-rank (Mantel-Cox) test. ResultsThe number of patients and stents in each group were as follows: AC group, 299 patients and 308 stents; and NAC group, 77 patients and 90 stents. The average age was 52.24 ± 13.44 years and 55.63 ± 14.49 years in the AC and NAC groups, respectively (P ≤ .065). Women constituted 76% of the patients in the AC group and 72% in the NAC group. The average stent diameter and length for the AC group was 20 ± 2 mm and 77 ± 13 mm and for the NAC group was 19 ± 2 mm and 82 ± 9 mm, respectively. The stents had been placed in the right common iliac vein, bilaterally, or left common iliac vein territory in 15%, 3%, and 82% in the AC group and 18%, 2%, and 80% in the NAC group, respectively. The cumulative stent patency at 30 months was 98.7% and 94.6% for the NAC and AC groups, respectively (P ≤ .83). All the stents placed were Wallstents (Boston Scientific, Marlborough, Mass). A total of eight insertion site thromboses occurred that did not affect stent patency: five in the AC group (1.6%) and three in the NAC group (4.5%; P = .15). In addition, 19 patients demonstrated evidence of thrombus layering, with 6 receiving extended anticoagulation. ConclusionsOur data indicate that perioperative stent thrombosis in patients with NIVLs is uncommon. Thus, anticoagulation for perioperative stent thrombosis prophylaxis is not necessary. Anticoagulation should only be used for patients with insertion site thromboses and should be considered if thrombus layering is observed on surveillance scanning.

Iliofemoral venous stenting in patients with central neuromuscular disorders

BackgroundLeg swelling in patients with various central neuromuscular disorders is a common clinical scenario and can lead to significant morbidity. The aim of the present study was to evaluate a subset of patients with central neuromuscular disorders who had undergone iliofemoral venous stenting at a specialty venous clinic at a tertiary care hospital. MethodsFrom January 2000 to December 2020, the medical records of all patients with a known central neuromuscular disorder who had undergone iliofemoral venous stenting for chronic iliofemoral venous obstruction were retrospectively analyzed. ResultsA total of 42 patients (45 limbs) with central neuromuscular disorders had undergone iliofemoral stenting after failure of a trial of conservative therapy. The central neuromuscular disorders included Parkinson disease (n = 20 limbs), multiple sclerosis (n = 15 limbs), and other neuromuscular conditions (n = 10 limbs). The mean age of the sample was 59 ± 14 years. The ratio of post-thrombotic to nonthrombotic iliac vein lesions was 3:1. Most of the patients had had CEAP (clinical, etiologic, anatomic, pathophysiologic) class ≥C4 (64.4%); 25 limbs had a history of venous thromboembolism (56%). A trend was seen toward improvement in all clinical parameters measured (venous clinical severity score, visual analog scale for pain score, and edema grade) after stenting. An ulcer healing rate of ≤90% was noted after stenting. Of the 45 limbs, 24 had required some form of reintervention (53%) after initial stent placement. ConclusionsVenous intervention in the form of endovenous stenting was associated with improvement in the clinical parameters for patients with central neuromuscular disorders. However, these patients should be counseled regarding the relatively higher rate of reinterventions that might be required to correct residual or recurrent symptoms.

Venous Stent Patency is Independent of Total Stented Length in Nonthrombotic Iliac Vein and Post-thrombotic Venous Stenoses

Venous stenting has become the preferred treatment of symptomatic iliofemoral venous obstruction due to nonthrombotic iliac vein lesions (NIVLs) and post-thrombotic venous stenoses (PTs). A paucity of data is available regarding the effect of stent length on patency rates after intervention. We evaluated the association between stent length and patency in patients treated for iliofemoral venous outflow obstruction.

Three-Year Results from the Venovo Venous Stent Study for the Treatment of Iliac and Femoral Vein Obstruction

PurposeTo assess safety and patency of the Venovo venous stent for the treatment of iliofemoral vein obstruction.Materials and MethodsTwenty-two international centers enrolled 170 patients in the VERNACULAR study (93 post-thrombotic syndrome; 77 non-thrombotic iliac vein lesions). Primary outcome measures were major adverse events at 30 days and 12-month primary patency (freedom from target vessel revascularization, thrombotic occlusion, or stenosis > 50%). Secondary outcomes included the Venous Clinical Severity Score Pain Assessment and Chronic Venous Quality-of-Life Questionnaire assessments (hypothesis tested). Secondary observations included primary patency, target vessel and lesion revascularization (TVR/TLR), and assessment of stent integrity through 36 months.ResultsFreedom from major adverse events through 30 days was 93.5%, statistically higher than a pre-specified performance goal of 89% (p = 0.032) while primary patency at 12 months was 88.6%, also statistically higher than a performance goal of 74% (p < 0.0001). Mean quality-of-life measures were statistically improved compared to baseline values at 12 months (p < 0.0001). Primary patency at 36 months was 84% (Kaplan–Meier analysis) while freedom from TVR/TLR was 88.1%. There was no stent embolization/migration, and no core laboratory assessed stent fractures reported through 36 months. Six deaths were reported; none adjudicated as device or procedure related.ConclusionThe Venovo venous stent was successfully deployed in obstructive iliofemoral vein lesions and met the pre-specified primary outcome measures through 12 months. At 3 years, primary patency was 84%, reintervention rates were low, standardized quality-of-life and pain measures improved from baseline, and there was no stent migration or fractures.Level of EvidenceLevel 2—prospective, multicenter, controlled clinical study without a concurrent control or randomization. Pre-specified endpoints were hypothesis-tested to performance goals derived from peer-reviewed clinical literature.Registration clinicaltrials.govUnique Identifier NCT02655887.

Early and Mid-Term Outcomes of Femoro-Ilio-Caval Vein Stent Implantation.

We sought to investigate mid-term clinical outcomes and identify risk factors in one of the largest comprehensive series reported of femoro-ilio-caval (FIC) vein stent placement. Endovascular intervention with balloon angioplasty and stenting of the iliac and common femoral veins has become first-line treatment for symptomatic deep venous outflow obstruction. We conducted a single-center, retrospective analysis of 180 patients who underwent FIC stent implantation between May 2017 and May 2019; 327 procedures were performed. Our primary objective was to evaluate a composite of stent thrombosis and stent restenosis. Secondary outcomes included individual predictors of in-stent restenosis (ISR) and in-stent thrombosis (IST), primary and secondary patency, access-site complications, major bleeding, pulmonary embolism, cardiovascular death, any death, intracranial bleeding, all-cause mortality, and components of major adverse cardiac and cerebrovascular events (MACCE) in a 24-month period. A total of 327 procedures were performed for 180 patients. At 2-year follow up, 78.3% of cases remained free of any complication. Primary outcome occurred in 53 procedures (16.2%) and was highest at early (<30 days) follow-up. Primary patency at 2-year follow-up was 78.43%. There were no deaths, 1 patient (0.3%) had a subdural hematoma, and 3 patients (0.9%) had MACCE. Age and post-thrombotic syndrome (PTS) were significant predictors of primary outcome. PTS and Venous Clinical Severity score (VCSS) ≥10 were found to have higher rates of thrombosis. Active smokers, the elderly, history of deep vein thrombosis (DVT), and VCSS ≥10 had a statistically significant elevated risk of ISR. Endovascular treatment with stent implantation for non-thrombotic iliac vein lesion and PTS is safe, with low morbidity, zero mortality, low complications, and persistent improvement of symptoms. Age and PTS were significant predictors of primary outcome.

Treatment of Nonthrombotic Iliac Vein Lesions.

Nonthrombotic iliac vein lesions (NIVLs) most frequently result from extrinsic compression of various segments of the common or external iliac vein. Patients develop symptoms associated with chronic venous insufficiency (CVI); female patients may develop symptoms of pelvic venous disease. Given that iliac vein compression can be clinically silent, a thorough history and physical examination is mandatory to exclude other causes of a patient's symptoms. Venous duplex ultrasound, insufficiency examinations, and axial imaging are most commonly used to assess for the presence of a NIVL. Catheter venography and intravascular ultrasound (IVUS) are the mainstay for invasive assessment of NIVLs and planning prior to stent placement. IVUS in particular has become the primary modality by which NIVLs are evaluated; recent evidence has clarified the lesion threshold for stent placement, which is indicated in patients with moderate to severe symptoms. In appropriately selected patients, stent placement results in improved pain, swelling, quality of life, and, when present, healing of venous stasis ulcers. Stent patency is well preserved in the majority of cases, with a low incidence of clinically driven need for reintervention. In this article, we will discuss the clinical features, workup, endovascular management, and treatment outcomes of NIVL.