Non-thrombotic Iliac Vein Lesions Research Articles

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

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. 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. 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). 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. 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.

Principles of Optimal Antithrombotic Therapy for Iliac VEnous Stenting (POATIVES): A national expert-based Delphi consensus study

ObjectiveManagement of antithrombotic therapy in patients undergoing venous stents has not yet reached consensus, and there are not any recommendations from published guidelines. We undertook a Delphi consensus from Chinese experts to develop recommendations regarding the preferred antithrombotic therapy in patients following venous stenting. MethodsThe phase 1 questionnaire was comprised of three clinical scenarios of venous stenting for non-thrombotic iliac vein lesions (NIVL), acute deep vein thrombosis (DVT), and post-thrombotic syndrome (PTS) and was sent to venous practitioners across China. In phase 2, the results of phase 1 were distributed to a panel of experts for evaluation along with a questionnaire encompassing a series of statements produced during phase 1. A modified Delphi method was used to reach consensus on recommendations through two rounds of surveys. ResultsThe phase 1 questionnaire was completed by 283 respondents. In phase 2, an expert panel consisting of 28 vascular surgeons and interventional radiologists was assembled and voted 17 statements relating to antithrombotic management after venous stenting for NIVL (4 statements), DVT (6 statements), and PTS (7 statements). The majority of the statements about the antithrombotic agent selection received a high consensus strength. ConclusionsBased on the national Delphi consensus of Chinese experts regarding antithrombotic therapy following iliac venous stenting in three common scenarios, most of the statements could be used to guide antithrombotic management following venous stenting. Further studies are required to clarify controversial issues including the dose and duration of anticoagulants, the role of antiplatelet agents, especially in patients with NIVL.

Risk factors for low back pain after iliac vein stenting for non-thrombotic iliac vein lesions

ObjectiveIliac vein stenting is an option being explored to treat chronic venous insufficiency. We have noted that our most common postoperative complication is low back pain after stent placement, which is occasionally quite severe. We wanted to investigate risk factors that are involved in this phenomenon and identify potentially modifiable factors. MethodsPatients who failed 3 months of conservative therapy had iliac vein interrogation performed. We limited the scope of this database to non-thrombotic iliac vein lesions treated in the office in which Wallstents were placed. Data were collected from September 2012 to August 2020 for 2308 consecutive outpatients who underwent 3747 procedures. Before August 2016, patients received pre-procedure oral valium (n = 2679) and thereafter, patients received intravenous (IV) sedation (n = 1068). A pain score, on a Likert scale ranging from 0 to 10, was assessed within 1 hour postoperatively. We analyzed the medications administered and correlated them with pain scores. ResultsThe average of all the pain scores was 0.86 (range, 0-10; standard deviation [SD], 2.00). Age had a slight inverse effect on pain scores (r = −0.12; P < .00001). Presenting signs (based upon CEAP) (P = .11) and body mass index (P = .88) did not have a significant effect on pain scores. Average pain score for females (0.96) was slightly higher than for males (0.70), with P < .0001. Average pain score for procedures on the right side (0.67) was lower than for procedures on the left side (1.01), with P < .0001. Average pain score for patients who received IV sedation (mean, 0.68; SD, 1.58) was lower than that for those who did not (mean, 0.93; SD, 2.15), with P = .0004. When using a single agent, propofol was associated with the lowest pain scores (P < .0001). Toradol displayed a dose-dependent effect on pain score (P < .0001). The best combination of agents for pain control was propofol and toradol together. ConclusionsOverall, the vast majority of pain scores were low. Factors that were associated with lower pain scores were older age, male sex, procedures on the right side, and IV sedation, in particular with the use of propofol. These data may help us better target patients anticipated to have high pain scores and suggest the preferential use of propofol and toradol.

An Evaluation of the Duration of Oral Anticoagulant Use Among Patients Undergoing Endovascular Treatment of Nonthrombotic Iliac Vein Lesions

This study aimed to compare clinical outcomes associated with the duration of postoperative direct oral anticoagulant (DOACs) therapy in patients with nonthrombotic iliac vein lesions. We retrospectively analyzed 176 consecutive patients who underwent stenting for nonthrombotic iliac vein lesions between March 2018 and December 2021. In total, 99 and 77 patients were discharged on a 3-month and >3-month regimen of DOAC therapy, respectively. The primary cumulative endpoint was a composite of thrombotic complications, bleeding complications, primary patency, primary-assisted patency, and secondary patency within 1year. Patients undergoing 3-month and >3-month DOAC therapy were similar in age, sex, lesion site, symptoms, and average stent diameter and length. Upon multivariate analysis, the primary cumulative endpoint did not differ between the 2 groups (hazard ratio [HR]: 1.18; 95% confidence interval [CI]: 0.42-3.30; P=0.76). Moreover, the primary patency at 1year did not differ between the groups (HR: 1.50; 95% CI: 0.14-16.54; P=0.74). Furthermore, there were no discernible differences in the secondary endpoints of bleeding complications (HR: 0.66; 95% CI: 0.22-1.96; P=0.45) or thrombotic complications (HR: 1.79; 95% CI: 0.55-5.80; P=0.34) between the groups. The 3-month regimen of DOAC therapy showed a similar risk of postoperative thrombosis and bleeding when compared to longer DOAC therapy durations over the course of 1year following endovascular intervention. This could be a preferred option for patients with a higher estimated bleeding risk after venous stenting.

Technical Feasibility and Clinical Efficacy of Iliac Vein Stent Placement in Adolescents and Young Adults with May-Thurner Syndrome.

To report technical feasibility and clinical efficacy of iliac vein stent placement in adolescent patients with May-Thurner Syndrome (MTS). Single-institution retrospective review of the medical record between 2014 and 2021 found 63 symptomatic patients (F = 40/63; mean age 16.1years, 12-20years) who underwent left common iliac vein (LCIV) stent placement for treatment of LCIV compression from an overriding right common iliac artery, or equivalent (n = 1, left IVC). 32/63 (50.7%) patients presented with non-thrombotic iliac vein lesions (NIVL). 31/63 (49.2%) patients presented with deep vein thrombosis of the lower extremity and required catheter-directed thrombolysis after stent placement (tMTS). Outcomes include technically successful stent placement with resolution of anatomic compression and symptom improvement. Stent patency was monitored with Kaplan-Meier analysis at 3, 6, 12, 24, and 36months. Anticoagulation and antiplatelet (AC/AP) regimens were reported. Technical success rate was 98.4%. 74 bare-metal self-expanding stents were placed in 63 patients. Primary patency at 12, and 24-months was 93.5%, and 88.9% for the NIVL group and 84.4% and 84.4% for the tMTS group for the same period. Overall patency for the same time intervals was 100%, and 95.4% for the NIVL group and 96.9%, and 96.9% for the tMTS group. Procedural complication rate was 3.2% (2/63) with no thrombolysis-related bleeding complications. Clinical success was achieved in 30/32 (93.8%) and 29/31 (93.5%) patients with tMTS and NIVL groups, respectively. CIV stent placement in the setting of tMTS and NIVL is technically feasible and clinically efficacious in young patients with excellent patency rates and a favorable safety profile.

Impact of stent compression in patients with non-thrombotic iliac vein lesions on iliac vein blood flow and related symptoms.

To study outcomes in patients with non-thrombotic iliac vein lesions (NIVLs) treated by stents. We performed a retrospective study that collected 109 patients from January 2016 to August 2020 diagnosed with symptomatic NIVLs. The patients underwent endovenous stenting using the Wallstents. Clinical severity was assessed using the venous clinical severity score and the Villalta scores. The patency was assessed using duplex ultrasound, while the diameters and the blood flow velocities (BFVs) in the proximal, middle, and distal stented segments were recorded simultaneously. A total of 128 stents were placed in 115 limbs (median age, 61years), with a mean follow-up of 32months. At 36months, the Villalta scores went from 12.17 to 3.64 (p < .001). The VCSS went from 9.41 to 3.31 (p < .001). The mean diameters in the proximal, middle, and distal stented segments were 8.52 ± 2.15mm, 10.13 ± 1.75mm, and 10.17 ± 1.69mm in the first month, while the mean BFVs were 31.17 ± 13.66cm/s, 31.07 ± 11.90cm/s, and 36.39 ± 18.41cm/s, respectively. Repeated-measures analysis in 55 consecutive patients from 1month to 3years after procedure revealed a decrease of the stent diameter in the proximal stented segment (p = .004); a stabilization of the stent diameter in the middle (p = .43) or distal (p = .45) stented segment; a steadiness of the BFVs in the proximal (p = .40), middle (p = .93), and distal (p = .25) stented segments; and an improvement in the VCSS (p = .03) and Villalta scores (p = .006). BFVs in stented segments remained steady and the symptoms in lower extremities improved after surgery, while stent compression was observed in the diameter of the proximal stented segment, with no impact on BFVs or symptoms.

Identifying venous clinical severity score thresholds for Clinical-Etiology-Anatomy-Pathophysiology classifications of venous edema and higher.

Venous Clinical Severity Score (VCSS) is a widely used standard for assessing and grading the severity of chronic venous disease (CVD). Prior research highlighted its high validity in detecting and quantifying venous disease. However, there is little, if any, known about the precise thresholds at which VCSS discriminates important stages of deep venous disease. This study sought to elucidate the diagnostic accuracy, thresholds, and correlation at which VCSS detects salient CEAP (Clinical-Etiology-Anatomy-Pathophysiology) classes in deep venous disease progression. A registry of 840 patients who presented with chronic proximal venous outflow obstruction (PVOO) secondary to non-thrombotic iliac vein lesions from August 2011 to June 2021 was retrospectively analyzed. VCSS and CEAP classifications were used to evaluate preoperative symptoms. VCSS was compared to CEAP classes to determine the precise VCSS composite values at which the instrument was able to detect CEAP C3 and higher, C4 and higher, and C5 and higher. Receiver operative characteristic (ROC) curve and area under the curve (AUC) were used to evaluate VCSS for its ability to discriminate disease at these stages of CEAP classification. Spearman's rank coefficient was used to determine the correlation between CEAP VCSS composite as well as individual VCSS components (pain, varicose vein, edema, pigmentation, inflammation, induration, ulcer number, ulcer size, ulcer duration, compression). VCSS composite was able to detect venous edema (C3) and higher at a sensitivity of 68.9% and a specificity of 54.8% at an optimized threshold of 8.5 (AUC = 0.648; 95% C.I. = 0.575-0.721). To detect changes in skin and subcutaneous tissue from CVD (C4) and higher, an optimal threshold of 11.5 was found with a sensitivity of 51.7% and specificity of 76.5% (AUC = 0.694; 95% C.I. = 0.656-0.731). Healed venous ulcer (C4) and higher was detectable at an optimized threshold of 13.5 at a sensitivity of 67.7% and a specificity of 88.9% (AUC = 0.819; 95% C.I. = 0.766-0.873). The correlation between VCSS composites and CEAP was weak (ρ = 0.372; p < .001). Attributes of VCSS that reflect more severe venous disease correlated more closely with CEAP classes, namely pigmentation (ρ = 0.444; p < .001), inflammation (ρ = 0.348; p < .001), induration (ρ = 0.352; p < .001), number of active ulcers (ρ = 0.497; p < .001), active ulcer size (ρ = 0.485; p < .001), and ulcer duration (ρ = 0.497; p < .001). The correlation between CEAP class and the other four components of VCSS were not statistically significant. VCSS composite thresholds of 8.5, 11.5, and 13.5 are threshold values for detecting CEAP classification C3 and higher, C4 and higher, and C5 and higher, respectively. Consistent with prior work, VCSS appears to have a better ability to discriminate CVD at more severe CEAP classifications. In this registry, the correlation between VCSS and CEAP was found to be weak while components of VCSS that suggest more advanced disease exhibited the strongest correlation with CEAP.

Editor's Choice – Quality of Life after Stenting for Iliofemoral Venous Obstruction: A Randomised Controlled Trial with One Year Follow Up

Deep venous obstruction (DVO) is a great burden on the healthcare system and patients' quality of life (QoL). Case series show stenting is safe and effective, however most studies lack control groups and QoL changes have not been compared with conventional treatment. The aim was to assess the difference in QoL changes from baseline to 12 months between stent and conventionally treated patients with DVO. Subjects > 18 years old with DVO due to post-thrombotic (PTS) or non-thrombotic iliac vein lesions (NIVLs) in a tertiary hospital were prospectively randomised to best medical therapy (BMT) or stent placement with BMT in a ratio 2:1, stratified for PTS or NIVL. The primary outcome was the between group difference in VEINES-QoL scores change from baseline to 12 months after treatment. Secondary outcomes included the difference in score changes for EuroQoL 5-Dimension 5 Level (EQ-5D-5L), Pain Disability Index (PDI), Venous Clinical Severity Score (VCSS), and the Villalta score. After three years, the inclusion rate dropped to almost zero, therefore the study had to be stopped. Sixty-three patients were randomised to either the stent (n= 42) or control group (n= 21). Overall, 50patients had available data for primary outcome analysis. The adjusted mean difference between 12month scores for VEINES-QoL and VEINES-Sym was 8.07 (95% CI 3.04 - 13.09) and 5.99 (95% CI 0.75 - 11.24) (p= .026), respectively, in favour of the stent group. The differences were significant, but a pre-defined meaningful 14 point improvement in QoL was not reached. The mean difference between 12 month scores for VCSS was -2.93 (95% CI -5.71 - 0.16, p= .040), -11.83 (95% CI -20.81 - 2.86, p= .011) for PDI, 0.015 (95% CI -0.12 - 0.15, p= .82) for the EQ-5D index, and -2.99 (95% CI -7.28 - 1.30, p= .17) for the Villalta score. Symptomatic patients with DVO who received dedicated venous stents had significantly higher VEINES-QoL/Sym scores at 12 months compared with the control group, but the between group difference was lower than the pre-specified clinically relevant QoL difference of at least 14 points. NCT03026049.

Inguinal intranodal lymphangiography reveals a high incidence of suprainguinal lymphatic disease in patients with leg edema undergoing stenting for symptomatic chronic iliofemoral venous obstruction

ObjectiveRecent studies have emphasized the important role lymphatics play in the drainage of interstitial fluid and edema prevention. Although the infrainguinal lymphatics have been studied in some depth, with patterns of pathology identified, such data above the groin are sparse, especially for patients with phlebolymphedema. The present study attempts to evaluate the status of lymphatic flow above the inguinal ligament in patients presenting with edema and undergoing stenting for symptomatic chronic iliofemoral venous obstruction (CIVO). MethodsA total of 31 lower limbs that underwent pedal lymphoscintigraphy for leg edema and subsequent stenting for symptomatic CIVO formed the study cohort. Each limb underwent intranodal lymphangiography of an ipsilateral inferior inguinal lymph node (10 mL of lipiodol) at the time of stenting. Fluoroscopic visualization of lipiodol transit was performed at 20, 40, and 60 minutes and 3 hours after injection. Enumeration of the lymph nodes and lymphatic collector vessels from above the inguinal ligament to L1, visualization of the thoracic duct, the time delay to visualization of the thoracic duct, and pathologic changes to the thoracic duct when present were all evaluated. These anomalies were independently scored, with the scores combined to generate a total suprainguinal score (range, 0-3). This score was then compared to the limb's lymphoscintigraphically derived infrainguinal score (total infrainguinal score range, 0-3) using the t test and Spearman correlation. The clinical outcomes (grade of swelling, venous clinical severity score) after stenting were appraised. ResultsOf the 30 patients (31 limbs), 18 were women, with left laterality noted in 23 limbs. A nonthrombotic iliac vein lesion occurred in 9 limbs and post-thrombotic syndrome in 22 limbs. Of the 31 limbs, 24 (77%) had suprainguinal lymphatic disease (SLD), with 22 of the 24 limbs having severe SLD and 2, mild SLD. When SLD was compared with infrainguinal lymphatic disease, 6 limbs (19%) had the same degree of involvement above and below the groin (1 with normal and 5 with severe disease), 17 limbs (55%) had more severe SLD, and 8 limbs (26%) had more severe infrainguinal lymphatic disease. Three limbs with normal pedal lymphoscintigraphic findings had severe SLD. The Spearman correlation coefficient for the comparison of SLD and infrainguinal disease in the same limb was 0.1 (P = .69). At baseline, the limbs with severe SLD had the same degree of leg swelling and venous clinical severity score as the limbs with absent to mild SLD (P > .1) with similar improvements after stenting (P > .4). Seven limbs underwent complex decongestive therapy (all with severe SLD and concomitant severe infrainguinal disease in one) to treat significant residual leg edema, with improvement. ConclusionsSLD appears to be common in patients with leg edema undergoing stenting for symptomatic CIVO. Such disease appears to affect the thoracic duct more commonly. Although patients with persistent or residual leg edema after stenting can benefit from complex decongestive therapy, further workup in the form of inguinal intranodal lymphangiography and targeted intervention might need to be considered for those who do not benefit from such therapy. Further study is warranted.

Stent deformations in the common iliac and iliofemoral veins as a result of hip flexion and extension

ObjectiveIn the present study, we characterized deformations of venous stents implanted into common iliac veins for nonthrombotic iliac vein lesions and iliofemoral veins for deep vein thrombosis due to hip movements commensurate with everyday activities such as walking, sitting, and stair climbing. MethodsPatients treated with iliofemoral venous stents were recruited from three centers and underwent imaging with two orthogonal two-dimensional projection radiographs. Stents in the common iliac veins and iliofemoral veins crossing the hip joint were imaged with the hip in 0°, 30°, 90° and −15°, 0°, and 30° positions, respectively. Using the radiographs, the three-dimensional geometries of the stents were constructed for each hip position, and the diametric and bending deformations between those positions were quantified. ResultsTwelve patients were included, and the findings showed that the common iliac vein stents experienced approximately twofold more local diametric compression with 90° hip flexion compared with 30° flexion. Also, iliofemoral vein stents crossing the hip joint experienced significant bending with hip hyperextension (−15°) but not with hip flexion. In both anatomic locations, maximum local diametric and bending deformations were in proximity with each other. ConclusionsStents implanted in the common iliac and iliofemoral veins exhibit greater deformation during high hip flexion and hyperextension, respectively, and iliofemoral venous stents interact with the superior ramus of the pubis during hyperextension. These findings suggest that device fatigue could be influenced by the type and level of patient physical activity, in addition to anatomic positioning, opening up the potential benefit of activity modification and the use of a careful implantation strategy. The proximity of maximum diametric and bending deformations means that simultaneous multimodal deformations should be considered for device design and evaluation.

Preprocedural imaging modalities in patients undergoing iliocaval venous recanalization and stent placement.

To determine the diagnostic accuracy of preinterventional imaging modalities in patients being evaluated for iliocaval venous recanalization and stent placement. Consecutive patients with iliocaval postthrombotic obstructions or nonthrombotic iliac vein lesions (NIVL), who were scheduled for recanalization, underwent duplex ultrasound (DUS), magnetic resonance venography (MRV), multiplanar venography (MPV), and intravascular ultrasound (IVUS). The diagnostic accuracies of DUS, MRV, and MPV were analyzed using IVUS as reference. A total of 216 limbs in 108 patients (80 patients with postthrombotic obstructions, 28 patients with NIVL) were examined. In patients with postthrombotic obstructions, the diagnostic sensitivities for the detection of lesions of the common femoral vein were 81% (95% CI 71-89%) for DUS, 76% (95% CI 65-85%) for MRV, and 86% (95% CI 76-93%) for MPV. The sensitivities for detecting lesions of the iliac veins were 96% (95% CI 89-99%) for DUS, 99% (95% CI 92-100%) for MRV, and 100% (95% CI 94-100%) for MPV. Regarding the inferior vena cava, the sensitivities were 44% (95% CI 24-65%) for DUS, 52% (95% CI 31-73%) for MRV, and 70% (95% CI 47-86%) for MPV. The sensitivities for detecting NIVL were 58% (95% CI 34-79%) for DUS, 90% (95% CI 68-97%) for MRV, and 95% (95% CI 73-99%) for MPV. In patients scheduled for recanalization of iliocaval postthrombotic obstructions, the sensitivities of DUS, MRV, and MPV were similar. In patients with suspected inferior vena cava involvement and in patients with NIVL, additional imaging with MR or conventional venography is required.

Outcomes of dedicated iliac venous stents during pregnancy and postpartum

ObjectiveThe aim of this study was to assess the performance of dedicated iliac venous stents during subsequent pregnancy and postpartum, including stent patency and stent integrity, as well as incidence of venous thromboembolism and bleeding complications. MethodsThis study included retrospective analysis of prospectively collected data of patients attending a private vascular practice. Women of child-bearing age who had received dedicated iliac venous stents were included in a surveillance program and then, for any subsequent pregnancies, followed the same pregnancy care protocol. This included an antithrombotic regime of 100 mg aspirin daily until gestation week 36, and subcutaneous enoxaparin at a dose dependent on risk of thrombosis: low-risk patients, those stented for non-thrombotic iliac vein lesion, received a prophylactic dose of 40 mg/day from the third trimester; high-risk patients, those stented for thrombotic indication, received a therapeutic dose of 1.5 mg/kg/day from the first trimester. All women underwent follow-up with duplex ultrasound assessment of stent patency during pregnancy and at 6 weeks postpartum. ResultsData was analyzed for a total of 10 women and 13 post-stent pregnancies. Stents were placed for non-thrombotic iliac vein lesions in seven patients, and for post-thrombotic stenoses in three patients. All stents were dedicated venous stents, and four crossed the inguinal ligament. All stents remained patent during pregnancy, at 6 weeks postpartum, and latest follow-up (median time post-stent, 60 months). There were no cases of deep vein thrombosis or pulmonary embolism, and no bleeding complications. There was only one reintervention case due to in-stent thrombus, and one case of asymptomatic stent compression. ConclusionsDedicated venous stents performed well through pregnancy and post-partum. A protocol including the use of low dose antiplatelets in combination with anticoagulation at either a prophylactic or therapeutic dose depending on the patient’s risk profile appears safe and effective.

Venous Clinical Severity Score has a suboptimal ability to detect improvement after iliac vein stenting across three years of follow-up

ObjectiveVenous Clinical Severity Score (VCSS) is currently the gold standard for measuring the severity of chronic venous disease, especially in patients with chronic proximal venous outflow obstruction (PVOO) secondary to non-thrombotic iliac vein lesions. Change in VCSS composite scores is often used to quantitatively measure the degree of clinical improvement after venous interventions. This study sought to assess the discriminative ability, sensitivity, and specificity of change in VCSS composites for detecting clinical improvement after iliac venous stenting. MethodsA registry of 433 patients who underwent iliofemoral vein stenting for chronic PVOO from August 2011 to June 2021 was retrospectively analyzed. These 433 patients had follow-up exceeding 1 year after the index procedure. Change in VCSS composite and clinical assessment scores (CAS) were used to quantify improvement after venous interventions. CAS is an assessment by the operating surgeon based on patient self-reporting to assess the degree of improvement at each clinic visit compared with before the index procedure longitudinally across the treatment course of a patient. Patients are rated as worse (−1), no change (0), mildly improved (+1), significantly improved (+2), and asymptomatic/complete resolution (+3) at every follow-up visit as compared with their disease severity prior to the procedure based on patient self-report. This study defined improvement as CAS >0 and no improvement as CAS ≤0. VCSS was then compared with CAS. Receiver operative characteristic curve and area under the curve (AUC) were used to evaluate change in VCSS composite for its ability to discriminate between improvement and no improvement after intervention at each year of follow-up. ResultsChange in VCSS was a suboptimal measure for discriminating clinical improvement (1-year AUC, 0.764; 2-year AUC, 0.753; 3-year AUC, 0.715). Across all three time points, a change in VCSS threshold of +2.5 maximized the sensitivity and specificity of the instrument to detect clinical improvement. At 1 year, change in VCSS at this threshold was able to detect clinical improvement at a sensitivity of 74.9% and specificity of 70.0%. At 2 years, VCSS change had a sensitivity of 70.7% and specificity of 66.7%. At 3 years of follow-up, VCSS change had a sensitivity of 76.2% and specificity of 58.1%. ConclusionsAcross 3 years, change in VCSS exhibited a suboptimal ability to detect clinical improvement in patients undergoing iliac vein stenting for chronic PVOO with considerable sensitivity but variable specificity at a threshold of 2.5.

The efficacy of stenting in the iliofemoral vein of patients with venous obstruction and secondary lymphedema from malignancy

ObjectiveTo investigate the safety and effectiveness of venous stenting in patients with chronic iliofemoral venous obstruction and secondary lymphedema from malignancy. MethodsFrom July 2012 to December 2020, patients with iliofemoral venous obstruction and secondary lymphedema who underwent venous stenting in our institution were reviewed retrospectively. Clinical characteristics, surgical complications, and symptom relief were assessed. Stent patency was evaluated with duplex ultrasound or computed tomographic venography. Twelve-month outcomes were reported. ResultsFifty-three patients with concurrent secondary lymphedema who had stents placed for iliofemoral venous obstruction were included. There were 42 females, and the mean age was 56.9 years. Nonthrombotic iliac vein lesions were identified in 16 patients (30.1%). Immediate technical success was 100%, with an average of two stents implanted. The median Villalta score, and Chronic Venous Disease Quality of Life quality of life questionnaire scores decreased from 12 (IQR, 10-15) and 58 (IQR, 50-66) at baseline, respectively, to 5 (interquartile range [IQR], 4-6) and 28 (IQR, 22-45) at 12 months after the procedure (P < .05), showing significant improvement in the quality of life. At the end of a median follow-up of 12 months (range, 3-25 months), the cumulative primary, assisted primary, and secondary patency rates were 70.8%, 76.9%, and 90.1%, respectively. ConclusionsIn patients with secondary lymphedema from malignancy, venous stent placement is safe and effective for iliofemoral venous obstruction.

Evaluation of 3-dimensional rotational venography for the diagnosis of non-thrombotic iliac venous lesion.

The purpose of this study was to determine the technical feasibility and safety of 3D rotational venography (3D-RV) in the diagnosis of non-thrombotic iliac vein lesions compared with traditional 2D-digital subtraction angiography (2-DSA). The general epidemiological data (including age, gender), clinical manifestations (including major symptom, affected extremity, CEAP classification, comorbidity, stenosis rate), and intra-operative findings (iliac vein indentation position, collateral circulation, procedure time, X-rays dose, contrast agent dosage) of 61 NIVL patients who were assessed by 3D-RV and traditional 2-DSA between October 2018 to October 2022 were obtained and analyzed. A total of 61 consecutive patients with symptomatic NIVL from our institution were enrolled in this study. With the aggravation of iliac vein stenosis, the proportion of indicators such as contralateral formation and iliac vein compression indentation reflecting the severity of compression under 3D-RV reconstruction increased significantly. Also, significant differences were observed between the 3D-RV and 2-DSA groups concerning procedure time (10.56 ± 0.09 s vs. 12.59 ± 0.37 s; p < 0.01), X-ray dose (41.25 ± 0.21 mGy vs. 81.59 ± 1.69 mGy; p < 0.01) and contrast agent dosage (21.48 ± 0.24 mL vs. 33.69 ± 0.72 mL; p < 0.01). Contralateral iliac vein imaging (p = 0.002), pelvic collateral vein imaging (p = 0.03), and external iliac vein indentation (p = 0.001) were found to influence the severity of iliac vein compression. 3D-RV can display dynamic stereo image information of NIVL, augmenting the information obtained from traditional 2-DSA. Contralateral iliac vein imaging, pelvic collateral vein imaging, and external iliac vein indentation can be used to evaluate the severity of iliac vein compression to some extent.

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.