BACKGROUND:Randomized trials of venous thrombolysis to prevent postthrombotic syndrome have produced mixed results. A method to identify patients most likely to benefit from interventional treatment is needed. This study evaluated a contrast-free, magnetic resonance-based multisequence thrombus imaging (MSTI) technique to characterize deep venous thrombi and predict susceptibility to thrombolysis. METHODS:Venous thrombosis was induced in the inferior vena cava of BALB/C mice (n=56, male), which were imaged up to 28 days postsurgery and 24 hours after systemic thrombolysis (Actilyse, 10 mg/kg, IV). The prelysis MSTI protocol included 3-dimensional T1 mapping, 3-dimensional magnetization transfer, and 2-dimensional diffusion-weighted imaging. Thrombolysis was defined as successful if inferior vena cava blood flow increased by ≥50% compared with prelysis values. In a clinical cohort, 41 patients with acute iliofemoral deep venous thrombi underwent MSTI before catheter-directed thrombolysis. Imaging parameters were analyzed against postintervention outcomes. RESULTS:MSTI identified thrombi susceptible to thrombolysis in both mice and humans. In mice, lysed thrombi showed lower T1 (723 [667-782] versus 874 [799-1000] ms; P<0.001) and higher apparent diffusion coefficient values (1.02 [0.96-1.14] versus 0.78 [0.62-0.88]×10-³ mm²/s; P<0.001) than nonlysable thrombi, with no difference in magnetization transfer. In patients, lysed thrombi demonstrated lower T1 (606 [543-656] versus 765 [630-909] ms; P<0.001), lower apparent diffusion coefficient (0.67 [0.5-1.1] versus 1.23 [0.69-1.74]×10-³ mm²/s; P=0.001), and similar magnetization transfer rates. Combining MSTI parameters optimized prediction, achieving 88% sensitivity and 97% specificity in mice, and 86% sensitivity and 91% specificity in humans. CONCLUSIONS:MSTI enables noninvasive, contrast-free characterization of thrombus composition and predicts thrombolytic susceptibility. This technique has the potential to guide patient selection for invasive therapies and should be incorporated into future trials of venous thrombosis treatment.

Objective: Ambulatory venous hypertension secondary to chronic inferior vena cava (IVC) and iliofemoral obstruction can have considerable impact on patient quality of life, including pain, edema, venous ulceration, and exercise intolerance. To date, there are no venous stents available in the United States specifically designed to treat iliocaval obstruction. The GORE VIAFORT Vascular Stent clinical trials investigate the safety and effectiveness of a novel venous stent developed for the treatment of symptomatic IVC obstruction, with or without iliofemoral obstruction, as well as unilateral symptomatic iliofemoral venous obstruction. Methods: Two prospective, nonrandomized, multicenter, single-armed clinical studies are being conducted at 34 clinical sites. The iliocaval study enrolled 89 patients in the United States, Europe, Australia, and New Zealand, with an additional 23 patients enrolled globally for regulatory purposes, for a total of 112 patients. Its primary end point is a composite measure that includes primary patency and freedom from stent embolization/migration at 12 months, as well as 30-day freedom from clinically significant pulmonary embolism and device- or procedure-related events (eg, death, major bleeding, or vascular injury requiring surgical or endovascular intervention). The iliofemoral study aims to enroll up to 165 patients in the United States. Its primary composite safety end point consists of freedom from stent embolization/migration at 12 months, as well as 30-day freedom from clinically significant pulmonary embolism and device- or procedure-related events (eg, death, major bleeding, and vascular injury requiring surgical or endovascular intervention). The distinct primary efficacy end point is primary patency through 12 months. Secondary end points for both studies include technical, lesion, and procedural success; primary and secondary patency; clinically driven target lesion revascularization; and device fractures through the 60-month follow-up, stent embolization through 12-month follow-up, and individual device- or procedure-related events through 30 days. Quality of life scores assessed through 60 months include revised Venous Clinical Severity Scale (rVCSS), rVCSS pain score, VEINES, Villalta, and EQ-5D-5L. The primary end points and the secondary end point of improvement in rVCSS pain score at 12 months will undergo formal hypothesis testing in both studies. All additional secondary end points will be summarized descriptively. Conclusions: The GORE VIAFORT Vascular Stent clinical trials are designed to evaluate the safety and efficacy of the unique GORE VIABAHN Venous Stent for the treatment of IVC and iliofemoral occlusive disease.

OBJECTIVE:Chronic venous disease (CVD) is a debilitating disease that results in significant morbidity and costs. A lack of standardised outcome reporting has made it difficult to evaluate the impact of interventions for CVD involving the deep veins. This study aimed to develop a core outcome set (COS) for studies evaluating interventions for this subset of CVD. METHODS:The COS was developed using the Core Outcome Measures in Effectiveness Trials (COMET) methodology. A systematic review and interviews with 19 patients experiencing post-thrombotic syndrome after deep vein thrombosis generated a longlist of outcomes, which was then refined by a steering group. Each outcome was rated on importance by patients and healthcare practitioners using a 9 point Likert scale within a Delphi survey. Outcomes not meeting consensus criteria in the first round were re-prioritised in a second round. Outcomes meeting the criteria for being critically important were discussed in a final meeting between patients and international experts to develop the COS. RESULTS:The review and interviews generated 80 outcomes, which entered the Delphi process. In total, 233 stakeholders responded in the first round and 143 in the second round. Consensus was reached on 29 outcomes deemed critically important. These outcomes were discussed in the final meeting to yield seven general outcomes and six procedure specific outcomes, since some outcomes were not relevant to all patients with CVD. The general outcomes were death, lower limb ulceration, venous thromboembolism, bleeding, quality of life, limb pain, and oedema or limb swelling. The procedure specific outcomes were device migration, device mechanical failure, patency, technical and/or procedural success, re-intervention, and vascular complications. CONCLUSION:A COS was developed for studies evaluating interventions for CVD involving the deep veins, comprising seven general outcomes and six procedure specific outcomes. Reporting these outcomes will promote comparison of interventions for CVD involving the deep veins.

BACKGROUND AND AIMS:Central venous obstruction (CVO) increases the complexity of pacing interventions, whether it be with device-associated symptomatic superior vena cava syndrome (SVCS), or by impeding new implants. Endovascular treatment involves the joint expertise of both cardiac pacing and vascular specialists. We report the outcomes of such procedures at our institution. METHODS:A single-center retrospective observational study, examining outcomes of joint pacing-vascular procedures for CVO. Cases were screened from an existing institutional database. RESULTS:There were 19 total cases. Two were new device implants where the novel "inside-out" procedure was utilized to establish access in SVCS, both with no complications. The remainder (n = 17) were transvenous lead extractions plus attempted recanalization of CVO using venoplasty with or without stenting. Transvenous devices were re-implanted in eight patients. Complete procedure success rate was 84%. There were two cases of pericardial effusion requiring pericardiocentesis, resulting in procedure abandonment. There was no in-hospital mortality and no cases of emergency sternotomy. Over mean follow-up of 28 months, 2/6 patients receiving venoplasty (33%) and 2/8 patients receiving stenting (25%) required re-intervention for symptomatic restenosis. Of the patients who were not re-implanted with a transvenous device following initially successful endovascular intervention (6/14), none had recurrence over the follow-up period. CONCLUSION:Pacing interventions in SVCS carry a significant risk profile, requiring management by experienced operators in high-volume centers to maximize safety. Endovascular interventions have a significant recurrence rate, with up-front stenting potentially being superior. Our data suggests that those without re-implantation of transvenous leads may have better long term outcomes.

Objective: Ambulatory venous hypertension secondary to chronic inferior vena cava (IVC) and iliofemoral obstruction can have considerable impact on patient quality of life, including pain, edema, venous ulceration, and exercise intolerance. To date, there are no venous stents available in the United States specifically designed to treat iliocaval obstruction. The GORE VIAFORT Vascular Stent clinical trials investigate the safety and effectiveness of a novel venous stent developed for the treatment of symptomatic IVC obstruction, with or without iliofemoral obstruction, as well as unilateral symptomatic iliofemoral venous obstruction. Methods: Two prospective, nonrandomized, multicenter, single-armed clinical studies are being conducted at 34 clinical sites. The iliocaval study enrolled 89 patients in the United States, Europe, Australia, and New Zealand, with an additional 23 patients enrolled globally for regulatory purposes, for a total of 112 patients. Its primary end point is a composite measure that includes primary patency and freedom from stent embolization/migration at 12 months, as well as 30-day freedom from clinically significant pulmonary embolism and device-or procedure-related events (eg, death, major bleeding, or vascular injury requiring surgical or endovascular intervention). The iliofemoral study aims to enroll up to 165 patients in the United States. Its primary composite safety end point consists of freedom from stent embolization/migration at 12 months, as well as 30-day freedom from clinically significant pulmonary embolism and device-or procedure-related events (eg, death, major bleeding, and vascular injury requiring surgical or endovascular intervention). The distinct primary efficacy end point is primary patency through 12 months. Secondary end points for both studies include technical, lesion, and procedural success; primary and secondary patency; clinically driven target lesion revascularization; and device fractures through the 60-month follow-up, stent embolization through 12-month follow-up, and individual device-or procedure-related events through 30 days. Quality of life scores assessed through 60 months include revised Venous Clinical Severity Scale (rVCSS), rVCSS pain score, VEINES, Villalta, and EQ-5D-5L. The primary end points and the secondary end point of improvement in rVCSS pain score at 12 months will undergo formal hypothesis testing in both studies. All additional secondary end points will be summarized descriptively. Conclusions: The GORE VIAFORT Vascular Stent clinical trials are designed to evaluate the safety and efficacy of the unique GORE VIABAHN Venous Stent for the treatment of IVC and iliofemoral occlusive disease. (JVS-Vascular Insights 2025;3:100295.)

BACKGROUND:Nutcracker syndrome (NCS) describes the symptomatic compression of the left renal vein between the aorta and superior mesenteric artery. Whereas asymptomatic compression is a common radiological finding, patients with NCS can report a range of symptoms. There are no specific diagnostic criteria and interventions include a range of open surgical and endovascular procedures. Therefore, we wished to develop an international consensus document covering aspects of diagnosis, management, and follow-up for patients with NCS. METHODS:A three-stage modified Delphi consensus was performed. A steering committee developed 37 statements covering 3 categories for patients with NCS: diagnosis, management, and follow-up. These statements were reported individually by 20 international experts in the management of venous disease, using a 5-point Likert scale. Consensus was defined if ≥70% of respondents rated the statement between 1 and 2 (agreement) and between 4 and 5 (disagreement). Those statements without consensus were recirculated in a second round of voting. A third round of the questionnaire was performed with 14 additional statements to clarify diagnostic values of NCS. RESULTS:Responses were returned by 20 of 20 experts (100%) in round one and 17 of 20 (85%) in round two. Initial consensus was reached in 24 of 37 statements (65%) spread over all categories. Round two achieved a further consensus on 5 out of 10 statements (50%). No categories reported consensus on all statements. In round two consensus was reached in the category of follow-up (4/5 statements [80%]). The final round reached consensus on 5 out of 14 statements (36%). Experts agreed that imaging is obligated to confirm NCS. Experts did not agree on specific diagnostic cut-off values. There was a consensus that the first choice of operative treatment is left renal vein transposition and that the risk of stent migration outweighs the advantages of a percutaneous procedure. CONCLUSIONS:Consensus was achieved on most statements concerning the assessment and management of NCS. This Delphi consensus identified those areas in which further research is needed, such as antiplatelet therapy, endovascular treatment, and renal autotransplantation. A rare disease registry to improve data and reports of patient outcomes is warranted.

Objective This systematic review and meta-analysis aimed to appraise recent evidence assessing patency outcomes at various time points in patients with superior vena cava, subclavian, and brachiocephalic vein stenosis who had undergone stenting. Data Sources PubMed, Scopus, and Cochrane Library databases were searched for studies up to December 2022. Review Methods Measured outcomes included technical success rate, primary, primary assisted, and secondary patency at various time points. A subgroup analysis was also conducted to compare malignant and benign obstruction. GRADE was used to assess the certainty of evidence. Results Thirty nine studies reporting outcomes in 1539 patients were included in the meta-analysis. Primary patency up to 1 year after the procedure was 81.5% (95% CI 74.5 – 86.9%). Primary patency declined after 1 year to 63.2% (95% CI 51.9 – 73.1%) at 12 – 24 months. Primary assisted patency and secondary patency at ≥ 24 months were 72.7% (95% CI 49.1 – 88.0%) and 76.6% (95% CI 51.1 – 91.1%). In the subgroup analysis, primary patency was significantly higher in patients with a malignant stenosis compared with a benign stenosis at 1 – 3 and 12 – 24 months. No significant difference was seen for pooled secondary patency rates when comparing the malignant and benign subgroups. GRADE analysis determined the certainty of evidence for all outcomes to be very low. Conclusion Stenting is an effective intervention for benign and malignant stenosis of the superior vena cava, subclavian, and brachiocephalic veins. Primary patency rates were good up to 1 year after the procedure, with 81.5% of stents retaining patency at 6 – 12 months. Patency rates declined after 1 year, to 63.2% primary and 89.3% secondary patency at 12 – 24 months, showing improved outcomes following re-intervention. High quality evidence is lacking. More research is needed to investigate patency outcomes and the need for surveillance or re-intervention programme.

Objective Chronic venous disease (CVD) is a debilitating disease that results in significant morbidity and costs. A lack of standardised outcome reporting has made it difficult to evaluate the impact of interventions for CVD involving the deep veins. This study aimed to develop a core outcome set (COS) for studies evaluating interventions for this subset of CVD. Methods The COS was developed using the Core Outcome Measures in Effectiveness Trials (COMET) methodology. A systematic review and interviews with 19 patients experiencing post-thrombotic syndrome after deep vein thrombosis generated a longlist of outcomes, which was then refined by a steering group. Each outcome was rated on importance by patients and healthcare practitioners using a 9 point Likert scale within a Delphi survey. Outcomes not meeting consensus criteria in the first round were re-prioritised in a second round. Outcomes meeting the criteria for being critically important were discussed in a final meeting between patients and international experts to develop the COS. Results The review and interviews generated 80 outcomes, which entered the Delphi process. In total, 233 stakeholders responded in the first round and 143 in the second round. Consensus was reached on 29 outcomes deemed critically important. These outcomes were discussed in the final meeting to yield seven general outcomes and six procedure specific outcomes, since some outcomes were not relevant to all patients with CVD. The general outcomes were death, lower limb ulceration, venous thromboembolism, bleeding, quality of life, limb pain, and oedema or limb swelling. The procedure specific outcomes were device migration, device mechanical failure, patency, technical and/or procedural success, re-intervention, and vascular complications. Conclusion A COS was developed for studies evaluating interventions for CVD involving the deep veins, comprising seven general outcomes and six procedure specific outcomes. Reporting these outcomes will promote comparison of interventions for CVD involving the deep veins.

Deep venous stent placement has developed into a primary treatment modality for venous obstruction in recent decades. Reported rates of complications are low in the literature and are based mainly on case reports and single-centre cohorts. Interventionalists performing these procedures must be aware of the occurrence of complications associated with stent placement to counsel patients adequately and promote avoidance through optimal procedural approach. This study aims to determine the incidence of serious complications associated with iliocaval and iliofemoral stent placement in a cohort of patients from 3 major tertiary deep venous referral centres. Data were collated from January 2014 to September 2023. The following major complications were included in the analysis: death, major bleeding requiring transfusion, massive pulmonary embolism, any complication which required endovascular or open surgical intervention, vessel rupture, acute kidney injury requiring dialysis, stent crushing, fracture, migration, involution or erosion. One thousand eight hundred fourteen (1814) patients were treated for acute or chronic deep venous pathology during the 9-year study period. Sixty-one patients (3.3

Objective: Early clot removal using endovascular intervention aims to reduce post-thrombotic syndrome (PTS) following iliofemoral deep venous thrombosis (DVT). This may reduce long term morbidity but incurs a higher initial cost. This study examined the cost effectiveness of catheter directed thrombolysis (CDT) and pharmacochemical thrombectomy (PMT) compared with oral anticoagulation (OAC) alone for treatment of acute iliofemoral DVT in the United Kingdom. Methods: A combined decision tree (acute DVT complications) and Markov model (long term complications [PTS]) was used for decision analytic modelling with five states: no PTS, mild PTS, moderate PTS, severe PTS, and dead. All patients started with acute DVT. Patients who survived acute complications transitioned into the Markov model. Cycle time was six months. A healthcare payer perspective and lifetime horizon was used, adjusting for excess mortality due to history of thrombosis. Data for probabilities, transition probabilities, mortality, and utilities were obtained from the published literature. Cost data were obtained from UK NHS tariffs and published literature. Outcomes were mean lifetime cost, quality adjusted life years (QALYs), and cost effectiveness. Results: Over a patient's lifetime, OAC was more costly (37 pound 206) than CDT (32 pound 043) and PMT (36 pound 288). Mean lifetime QALYs for OAC (12.9) were lower than CDT (13.5) and PMT (13.3). Therefore, in the incremental cost effectiveness analysis, both CDT and PMT were dominant: CDT was less costly (-5 pound 163) and more effective (+0.6 QALYs) than OAC, and PMT was also less costly (-917) pound and more effective (+0.3 QALYs) than OAC. Results were robust to univariable sensitivity analyses, but probabilistic sensitivity analyses suggested Conclusion: Early interventional treatment of iliofemoral DVT is cost effective in the UK. Future clinical and epidemiological studies are needed to characterise parameter uncertainty. Further analysis of modern practice, alternative treatments, and optimised care models is warranted.

Catheter-directed interventions for acute iliofemoral deep venous thrombosis (DVT) have been increasingly used over the past 15 years to target severe symptomatology and prevention of post-thrombotic syndrome incidence or reduce its severity if it were to develop. Aside from successful thrombus removal, adjunctive stents are frequently required to treat an uncovered lesion or significant fi cant residual thrombus to ensure quality of life improvement besides retarding DVT recurrence and post-thrombotic syndrome. As the evidence is mounting, the need and role for stenting, as well as the principles of an optimal technique, in the acute DVT setting are now better understood. Accumulating experience appears to favor stenting in the acute setting. The diameter of the stent, the length, the extent of overlapping, and the landing zones are crucial determinants of a successful durable outcome. This article endeavors to guide the interventionalist on stenting when encountering a patient with acute symptomatic iliofemoral DVT with concerns of quality of life impairment. (J Vasc Surg Venous Lymphat Disord 2024;12:101868.)

OBJECTIVE:This retrospective, multicentre study aimed to assess the prognostic value of a proposed classification system for chronic venous obstruction (CVO) patients undergoing successful interventional procedures. METHODS:This study analysed data from 13 vascular centres, including 1 033 patients with CVO treated between 2015 - 2019. The patients were classified into five category types: 1 - non-thrombotic iliac vein lesion; 2 - CVO of iliac segment; 3 - CVO of iliofemoral segment above common femoral vein confluence; 4 - CVO of iliofemoral segment extending into the femoral vein (FV) or deep femoral vein (DFV); and 5 - CVO of iliofemoral segment involving both DFV and FV. Stent deployment, complications, and follow ups were evaluated. Uni- and multivariable analyses were performed to identify predictors of primary patency loss. RESULTS:The mean age of the patients was 44.0 ± 14.7 years, with 59.9% being women. A median of two stents was used for unilateral cases and five stents for bilateral cases. At twelve months follow up, primary patency rates for types 1 - 5 were 94.9%, 90.3%, 80.8%, 60.6%, and 39.4%, respectively. These rates were strongly correlated with the extent of CVO and showed significant differences between each type. Univariable analysis identified predictors of primary patency loss as the type of CVO, history of deep vein thrombosis, and the total number of stents. In the multivariable analysis, the significant independent predictors of primary patency loss were the type of CVO and the total number of stents. CONCLUSION:The proposed anatomical classification of iliofemoral CVO will help to predict intervention outcomes and facilitate comparison of stent outcomes in future studies. However, further evaluation and validation in prospective studies are needed to confirm the utility of this classification.

Complications after iliofemoral and inferior vena cava stenting are rare, and most can be managed effectively without significant long-term consequences for the patient. Nevertheless, the procedure is not without risk, and clinicians considering starting a venous practice must be aware of the range of complications that can occur, which range from minor access site bleeds to fatal arrhythmia from stent migration to the heart. Most complications can be avoided with appropriate patient selection, stent sizing, and careful access and deployment techniques.

Objective Iliofemoral venous obstructive disease can result in significant, potentially debilitating symptoms that can negatively affect quality of life. Unlike arterial disease, patients with deep venous disease have a significantly lower median age, therefore the need for long term stent patency becomes a matter of decades rather than years. Furthermore, iliofemoral lesions frequently require stent placement across the inguinal ligament. Such stents are subject to dynamic stress from leg movement and associated concerns for device fatigue, resulting in stent fracture. The aim of this study was to describe an in vitro 50 year stent fatigue test method designed to assess durability against dynamic stress induced device fracture. Methods Through literature review, cadaver studies, and computer modelling, the most challenging loading was confirmed to be hip flexion across the inguinal ligament. This occurs when the patient adjusts between a seated and standing position. Sit to stand hip flexion at the inguinal ligament was effectively simulated on the bench in this in vitro experimental study. Results When tested under challenge parameters, hip flexion was reliably found to cause fractures in non-venous nitinol stents. However, a dedicated self expanding nitinol venous stent, engineered for improved durability, underwent up to 50 years of simulated loading on the bench with 15% (3/20) of stents experiencing fractures at 50 years, compared with fractures in 35% (14/40) of non-venous stents tested to 1.4 years; no statistical testing was performed as durations do not match and the objective was to demonstrate the test method). Conclusion The presented fatigue test method is a suitable approach for evaluating the durability of stents intended for venous use. Venous stents demonstrated superior fatigue resistance compared with non-venous stents via in vitro hip flexion testing.

Catheter-directed interventions for acute iliofemoral deep venous thrombosis (DVT) have been increasingly used over the past 15 years to target severe symptomatology and prevention of post-thrombotic syndrome incidence or reduce its severity if it were to develop. Aside from successful thrombus removal, adjunctive stents are frequently required to treat an uncovered lesion or significant residual thrombus to ensure quality of life improvement besides retarding DVT recurrence and post-thrombotic syndrome. As the evidence is mounting, the need and role for stenting, as well as the principles of an optimal technique, in the acute DVT setting are now better understood. Accumulating experience appears to favor stenting in the acute setting. The diameter of the stent, the length, the extent of overlapping, and the landing zones are crucial determinants of a successful durable outcome. This article endeavors to guide the interventionalist on stenting when encountering a patient with acute symptomatic iliofemoral DVT with concerns of quality of life impairment.

Travelling introduces a potentially increased risk of deep vein thrombosis (DVT). This may be enhanced following varicose vein surgery, but travel advice given to patients is not consistent. This aim was to establish guidelines for thromboprophylaxis during travel.