Plasma kallikrein supports FXII-independent thrombin generation in mouse whole blood.

Plasma kallikrein (PKa) is an important activator of factor (F)XII of the contact pathway of coagulation. Several studies have shown that PKa also possesses procoagulant activity independent of FXII, likely through its ability to directly activate FIX. We evaluated the procoagulant activity of PKa using a mouse whole blood (WB) thrombin generation (TG) assay. TG was measured in WB from PKa-deficient mice using contact pathway or extrinsic pathway triggers. PKa-deficient WB had significantly reduced contact pathway-initiated TG compared to wild-type controls and was comparable to that observed in FXII-deficient WB. PKa-deficient WB supported equivalent extrinsic pathway-initiated TG compared to wild-type controls. Consistent with the presence of FXII-independent functions of PKa, targeted blockade of PKa with either small molecule or antibody-based inhibitors significantly reduced contact pathway-initiated TG in FXII-deficient WB. Inhibition of activated FXII (FXIIa) using an antibody-based inhibitor significantly reduced TG in PKa-deficient WB, consistent with a PKa-independent function of FXIIa. Experiments using mice expressing low levels of tissue factor demonstrated that persistent TG present in PKa- and FXIIa-inhibited WB was driven primarily by endogenous tissue factor. Our work demonstrates that PKa contributes significantly to contact pathway-initiated TG in the complex milieu of mouse WB and that a component of this contribution occurs in a FXII-independent manner.

EXTENT study: Medium-term outcomes of EXTra-design engineering inner-branch ENdografts for the treatment of complex aortic aneurysms from a multicenter collaboration.

OBJECTIVE: This study aims to present the medium-term outcomes of Extra-Design engineering endografts with inner branches (EDE-iBEVARs, Artivion) in endovascular aortic repairs of complex aneurysms building upon promising early results. METHODS: A retrospective, international, multi-center study was conducted including consecutive patients who underwent complex endovascular aortic repairs using EDE-iBEVARs between 2018 and 2022. Patient demographics, aneurysm anatomical features, procedural details, reinterventions, complications, and endograft failures during follow-up were assessed. The primary outcome was aneurysm-related mortality. Secondary outcome measures included the freedom from all-cause mortality and reintervention, technical and clinical success, and late related complications including branch instability, endoleaks, and serious adverse events. RESULTS: Our study encompassed a total of 260 patients across 13 European centers. The cohort included patients with thoracoabdominal aortic aneurysms (n = 116), suprarenal or juxta-renal aneurysms (n = 95), and those who had previous open repair or previous endovascular aortic repair with type 1A endoleak (n = 49). Of 982 possible inner branches (937 antegrade and 45 retrograde), 962 (98%) were successfully cannulated and bridged with covered stents during the index procedure. Overall, the endograft was successfully deployed in 98% of patients, and 93% were discharged from hospital following surgery. At 3 years, freedom from aneurysm-related mortality was 97%, whereas the freedom of all-cause mortality was 89%. Freedom from reinterventions was 91% and 76% at 1 and 3 years, respectively. The rate of late complications such as endoleaks or branch instability events was 12% (n = 30). The late branch occlusion rate during follow-up was 1.5% (n = 15), of which 12 were renal branches. CONCLUSIONS: EDE-iBEVARs demonstrate satisfactory medium-term outcomes with reintervention rates comparable to other endografts. Encouragingly, rates of branch patency were high, and major adverse events were low. This technology could expand the treatment options for patients with challenging complex aortic conditions.

Molecular magnetic resonance imaging of myeloperoxidase activity identifies culprit lesions and predicts future atherothrombosis.

Aims: Unstable atherosclerotic plaques have increased activity of myeloperoxidase (MPO). We examined whether molecular magnetic resonance imaging (MRI) of intraplaque MPO activity predicts future atherothrombosis in rabbits and correlates with ruptured human atheroma. Methods and results: Plaque MPO activity was assessed in vivo in rabbits (n = 12) using the MPO-gadolinium (Gd) probe at 8 and 12 weeks after induction of atherosclerosis and before pharmacological triggering of atherothrombosis. Excised plaques were used to confirm MPO activity by liquid chromatography-tandem mass spectrometry (LC-MSMS) and to determine MPO distribution by histology. MPO activity was higher in plaques that caused post-trigger atherothrombosis than plaques that did not. Among the in vivo MRI metrics, the plaques' R1 relaxation rate after administration of MPO-Gd was the best predictor of atherothrombosis. MPO activity measured in human carotid endarterectomy specimens (n = 30) by MPO-Gd-enhanced MRI was correlated with in vivo patient MRI and histological plaque phenotyping, as well as LC-MSMS. MPO-Gd retention measured as the change in R1 relaxation from baseline was significantly greater in histologic and MRI-graded American Heart Association (AHA) type VI than type III-V plaques. This association was confirmed by comparing AHA grade to MPO activity determined by LC-MSMS. Conclusion: We show that elevated intraplaque MPO activity detected by molecular MRI employing MPO-Gd predicts future atherothrombosis in a rabbit model and detects ruptured human atheroma, strengthening the translational potential of this approach to prospectively detect high-risk atherosclerosis.

Intra-arterial Fractional Flow Reserve Measurements Provide an Objective Assessment of the Functional Significance of Peripheral Arterial Stenoses.

OBJECTIVE: Peripheral arterial stenoses (PAS) are commonly investigated with duplex ultrasound (DUS) and angiography, but these are not functional tests. Fractional flow reserve (FFR), a pressure based index, functionally assesses the ischaemic potential of coronary stenoses, but its utility in PAS is unknown. FFR in the peripheral vasculature in patients with limb ischaemia was investigated. METHODS: Patients scheduled for angioplasty and or stenting of isolated iliac and superficial femoral artery stenoses were recruited. Resting trans-lesional pressure gradient (Pd/Pa) and FFR were measured after adenosine provoked hyperaemia using an intra-arterial 0.014 inch flow and pressure sensing wire (ComboWire XT, Philips). Prior to revascularisation, exercise ABPI (eABPI) and DUS derived peak systolic velocity ratio (PSVR) of the index lesion were determined. Calf muscle oxygenation was measured using blood oxygenation level dependent cardiovascular magnetic resonance prior to and after revascularisation. RESULTS: Forty-one patients (32, 78%, male, mean age 65 ± 11 years) with 61 stenoses (iliac 32; femoral 29) were studied. For lesions < 80% stenosis, resting Pd/Pa was not influenced by the degree of stenosis (p = .074); however, FFR was discriminatory, decreasing as the severity of stenosis increased (p = .019). An FFR of < 0.60 was associated with critical limb threatening ischaemia (area under the curve [AUC] 0.87; 95% CI 0.75 - 0.95), in this study performing better than angiographic % stenosis (0.79; 0.63 - 0.89), eABPI (0.72; 0.57 - 0.83), and PSVR (0.65; 0.51 - 0.78). FFR correlated strongly with calf oxygenation (rho, 0.76; p < .001). A greater increase in FFR signalled resolution of symptoms and signs (ΔFFR 0.25 ± 0.15 vs. 0.13 ± 0.09; p = .009) and a post-angioplasty and stenting FFR of > 0.74 predicted successful revascularisation (combined sensitivity and specificity of 95%; AUC 0.98; 0.91 - 1.00). CONCLUSION: This pilot study demonstrates that FFR can objectively measure the functional significance of PAS that compares favourably with visual and DUS based assessments. Its role as a quality control adjunct that confirms optimal vessel patency after angioplasty and or stenting also merits further investigation.

HTATIP2 regulates arteriogenic activity in monocytes from patients with limb ischemia.

Use of autologous cells isolated from elderly patients with multiple comorbidities may account for the modest efficacy of cell therapy in patients with chronic limb threatening ischemia (CLTI). We aimed to determine whether proarteriogenic monocyte/macrophages (Mo/MΦs) from patients with CLTI were functionally impaired and to demonstrate the mechanisms related to any impairment. Proarteriogenic Mo/MΦs isolated from patients with CLTI were found to have an impaired capacity to promote neovascularization in vitro and in vivo compared with those isolated from healthy controls. This was associated with increased expression of human HIV-1 TAT interactive protein-2 (HTATIP2), a transcription factor known to suppress angiogenesis/arteriogenesis. Silencing HTATIP2 restored the functional capacity of CLTI Mo/MΦs, which was associated with increased expression of arteriogenic regulators Neuropilin-1 and Angiopoietin-1, and their ability to enhance angiogenic (endothelial tubule formation) and arteriogenic (smooth muscle proliferation) processes in vitro. In support of the translational relevance of our findings, silencing HTATIP2 in proarteriogenic Mo/MΦs isolated from patients with CLTI rescued their capacity to enhance limb perfusion in the ischemic hindlimb by effecting greater angiogenesis and arteriogenesis. Ex vivo modulation of HTATIP2 may offer a strategy for rescuing the functional impairment of pro-angio/arteriogenic Mo/MΦs prior to autologous delivery and increase the likelihood of clinical efficacy.

Device profile of EndoAnchors for aortic stent graft implantation: overview of their safety and efficacy.

INTRODUCTION: Endovascular aneurysm repair (EVAR) and thoracic endovascular aneurysm repair (TEVAR) are established techniques to treat abdominal aortic aneurysms (AAA) and thoracic aortic aneurysms (TAA). However, there are limitations when challenging proximal neck anatomy is present. Heli-FX EndoAnchors have been used in addition to EVAR and TEVAR to improve proximal sealing of a stent-graft, but there are limited data available on their outcomes, safety, and efficacy. AREAS COVERED: The properties and development of Heli-FX EndoAnchors are evaluated. The evidence of various clinical outcomes, safety, and efficacy is interrogated with the augmented use of Heli-FX EndoAnchors with EVAR or TEVAR. EXPERT OPINION: Challenging proximal neck anatomy can be problematic during EVAR or TEVAR. EndoAnchors may be part of the solution - used either prophylactically or therapeutically. The safety and efficacy databases are building but long-term data are still not available for this device and there remains inadequate data to support its routine use. Judicious patient selection is still needed.

Factors that influence the feasibility and implementation of a complex intervention to improve the treatment of peripheral arterial disease in primary and secondary care: a qualitative exploration of patient and provider perspectives.

OBJECTIVES: Our aim was to examine the feasibility and implementation of a complex intervention to improve the care of patients with peripheral arterial disease (the LEGS intervention) from the perspective of patients, general practitioners and secondary care clinicians. DESIGN: A qualitative study involving semistructured individual interviews with patients and providers to gain an understanding of the feasibility of the LEGS intervention as well the barriers and facilitators to implementation in secondary and primary care. SETTING: Primary and secondary care settings across two National Health Service Trusts. PARTICIPANTS: Twenty-five semistructured telephone interviews were conducted with (1) patients who had received the intervention (n=11), (2) secondary care clinicians responsible for delivering the intervention (n=8) and (3) general practitioners (n=6). ANALYSIS: Data were initially analysed using inductive descriptive thematic analysis. The consolidated framework for implementation research was then used as a matrix to explore patterns in the data and to map connections between the three participant groups. Lastly, interpretive analysis allowed for refining, and a final coding frame was developed. RESULTS: Four overarching themes were identified: (1) the potential to make a difference, (2) a solution to address the gap in no man's land, (3), prioritising and making it happen and (4) personalised information and supportive conversations for taking on the advice. The impetus for prioritising and delivering the intervention was further driven by its flexibility and adaptability to be tailored to the individual and to the environment. CONCLUSIONS: The LEGS intervention can be tailored for use at early and late stages of peripheral arterial disease, provides an opportunity to meet patient needs and can be used to promote shared working across the primary-secondary care interface.

Long-Term Effects of Acute Kidney Injury Following Endovascular Femoropopliteal Intervention: Insights From a Multicenter Trial.

PURPOSE: To examine the association between acute kidney injury (AKI) severity and duration with cardiovascular mortality, following endovascular treatment of femoropopliteal disease, and whether it is AKI in itself that confers an increased risk of cardiovascular mortality. METHODS: A retrospective analysis of prospectively collected data obtained between 2014 and 2019 from 3 vascular centers. Renal function was followed up for a minimum of 90 days. Electronic records were queried to establish a cause of death, where applicable. Patients were excluded if unable to provide written informed consent or if presenting with acute limb ischemia. Primary outcomes were the hazard ratios for cardiovascular death (AKI patients vs no AKI; no AKI vs stage 1 AKI vs stage 3 AKI; and no AKI vs transient AKI vs established AKI). Propensity score-matched analysis was used to establish whether developing AKI, in patients with similar demographics and procedural characteristics, is associated with a higher risk of cardiovascular death. RESULTS: Overall 239 patients developed AKI, and this was associated with an increased risk of cardiovascular mortality (hazard risk [HR]: 4.3, 95% confidence intervals [CIs]: 2.1-6.8, pairwise comparison p value=0.006]. This was dependent on the severity of the AKI stage (HR 5.4, 95% CI: 2.4-7.3, pairwise comparison p value=0.01) and duration (HR 4.2, 95% CI: 2.3-6.2, pairwise comparison p value=0.04). The propensity score-matched analysis showed that even when patients are matched for comorbidity and procedural characteristics, AKI confers an increased risk of mortality (p=0.04). CONCLUSIONS: Acute kidney injury is common after femoropopliteal endovascular therapy. It confers an increased risk of long-term cardiovascular mortality, which is still present when renal decline is transient, and highest for patients with established decline in renal function. CLINICAL IMPACT: This is the first study in the setting of peripheral arterial disease to show that acute kidney injury has an adverse effect on cardiovascular mortality, in the long-term, that is dependent on its severity, and present even when the AKI is transient. We have also shown that this difference in cardiovascular mortality becomes more pronounced from the medium-term, and thus closer follow-up of these patients is required.

Medium Term Outcomes of Deep Venous Stenting in the Management of Venous Thoracic Outlet Syndrome.

OBJECTIVE: Venous thoracic outlet syndrome (vTOS) is a relatively rare condition associated with significant morbidity. Its management continues to evolve, with increasing use of endovascular adjuncts, such as percutaneous thrombectomy and angioplasty, in addition to first rib resection. The utility of stenting residual venous stenotic lesions is poorly defined within the literature. This study sought to review the medium term patency rates of upper limb deep venous stenting in the management of vTOS. METHODS: A single centre, retrospective review of patients managed for vTOS with first rib resection followed by upper limb deep venous stenting between January 2012 and February 2021 was conducted. Post-procedural ultrasounds were reviewed to determine stent patency. RESULTS: Twenty-six patients were included, with 33 stents placed. The median duration of follow up was 50 months. On venous duplex ultrasound at three years post-operatively, primary patency rates were 66%, primary assisted patency rates were 88%, secondary patency rates were 91%, and total occlusion rates were 9%. After stent placement, 80% of patients remained asymptomatic with regard to compression symptoms. CONCLUSION: Upper limb deep venous stenting is an effective adjunct to surgical decompression in the management of vTOS. Stent medium term patency rates are promising; however, further studies with longer follow up and larger cohorts with multicentre results are required to confirm these early findings.

Risk factors and classification of reintervention following deep venous stenting for acute iliofemoral deep vein thrombosis.

BACKGROUND: Acute iliofemoral deep vein thrombosis (DVT) is associated with the development of post-thrombotic syndrome (PTS). Thrombolysis and deep venous stenting can restore vessel outflow and can reduce the incidence of PTS. However, for a proportion of patients, subsequent stenosis or reocclusion will necessitate further intervention. In the present study, we aimed to identify the risk factors, examine the outcomes (reintervention success and PTS), and develop a classification system for reintervention. METHODS: A retrospective single-center cohort study of patients who had undergone successful lysis for iliofemoral DVT from 2013 to 2017. The patients' records and imaging studies were examined for demographics, risk factors, extent of thrombus and vessel clearance, stenting, flow, reintervention, anticoagulation compliance, Villalta score, and secondary patency. From our findings, a system of classification for patients for whom procedures have failed was developed, constituting technical, hematologic, flow related, or multiple factors. RESULTS: Of 143 limbs (133 patients), 48 (33.6%) had required reintervention, of which 25 had presented with reocclusion (17.4%). The median time to reintervention was 45 days. The need for reintervention was associated with inferior vena cava thrombus (risk ratio [RR], 2.16; P < .01), stenting across the inguinal ligament (RR, 2.08; P < .01), and anticoagulation noncompliance (RR, 7.09; P < .01). Successful reintervention was achieved in 31 limbs (64.6%): 23 of 23 (100%) treated before occlusion vs 8 of 25 (36.4%) treated after occlusion (RR, 32.31; P < .01). A greater incidence of any PTS was observed for patients requiring reintervention (median Villalta score, 3 [interquartile range, 1-5]; vs 1 [interquartile range, 1-4]; RR, 2.28; P = .029). Cases without complete vessel occlusion (reintervention and control) had a lower rate of any PTS (14.0% vs 42.9%; RR, 3.06; P < .01) and moderate to severe PTS (3.0% vs 14.3%; RR, 4.76; P = .046) Technical issues were observed in 54.2% of reintervention cases and 6.3% of cases not requiring reintervention (P < .01). Hematologic issues were identified in 33.3% of reintervention cases and 1.1% of cases not requiring reintervention (P < .01). Flow-related issues were observed in 43.8% of the reintervention cases and no cases not requiring reintervention (P < .01). Of the reintervention cases, 27.1% were multifactorial and were associated with a lower rate of vessel salvage; however, this did not translate into a significant difference in secondary patency on survival analysis (RR, 1.70; P = .429). CONCLUSIONS: A large proportion of patients required reintervention because of potentially preventable factors. Anticoagulation compliance, thrombus burden, and poor flow are important risk factors to consider in patient selection. Reintervention increased the risk of PTS and was more often successful when achieved before vessel occlusion.

Performance of Open and Closed Cell Laser Cut Nitinol Stents for the Treatment of Chronic Iliofemoral Venous Outflow Obstruction in Patients Treated at a Single Centre.

OBJECTIVE: A number of dedicated self expanding nitinol stents have been developed for use in the venous system, with both open cell (OC) and closed cell (CC) designs available. Data comparing these different designs are lacking. The objective of this study was to evaluate outcomes in patients treated with open and closed cells for unilateral chronic iliac vein obstruction. METHODS: A single centre retrospective cohort study was conducted, including all patients treated with a dedicated nitinol venous stent between 2014 and 2019. Stent patency and details of re-interventions (including lysis, venoplasty, reinforcement, extension, arteriovenous fistula formation) were examined in the first post-operative year. Subgroup analysis described outcomes for patients treated with OC and CC stents ending above the inguinal ligament and those who required extension into the common femoral vein. Cox regression analysis was used to identify factors associated with loss of primary patency. RESULTS: A total of 207 patients were included (OC 100 patients, CC 107 patients). There was no significant difference between the groups for age (OC 42 years, CC 44 years); gender (OC and CC 67% female); presence of post-thrombotic lesions (OC 71%, CC 73%); stenting across the inguinal ligament (OC 58%, CC 56%), or presence of inflow disease (OC 49%, CC 47%). Primary and cumulative patency at 12 months were similar between groups (primary: OC 63%, CC 65%; cumulative: OC 93%, CC 90%). Patients with a CC stent across the inguinal ligament had a greater risk of needing multiple re-interventions at one year compared with those with an OC stent (odds ratio 2.84, 95% confidence interval [CI] 1.16 - 6.9) but overall, the only factor significantly associated with loss of primary patency was inflow vessel disease (hazard ratio 3.39, 95% CI 1.73 - 6.62, p < .001). CONCLUSION: OC and CC dedicated nitinol venous stents were observed to perform similarly in terms of patency and symptom improvement at one year. Disease of the inflow vessels was the most important factor associated with a loss of stent patency irrespective of stent design.

A Community and Hospital cAre Bundle to improve the medical treatment of severe cLaudIcation and critical limb iSchaemia (CHABLIS).

Background: Patients with peripheral artery disease (PAD) often do not receive optimal best medical therapy (BMT). Through interaction with patients and healthcare-professionals (HCPs) we developed the LEaflet Gp letter Structured checklist (LEGS) complex clinical intervention to support HCPs in providing guideline-compliant PAD BMT. Methods: This was a prospective multicentre study assessing the feasibility and fidelity of delivering the LEGS intervention in primary and secondary care over six months. Intervention fidelity was scored based on the proportion of intervention components used correctly at discharge, 30 days, and six months. Results: Overall, 129 individuals were screened and 120 took part (33% female, 74% with chronic limb threatening ischaemia; 93% recruitment rate). Of those, 118 (98% retention rate) completed follow-up. Mean intervention fidelity score at discharge (primary outcome measure) was 63% [95% Confidence Interval (CI): 39-68%, SD: 5%], exceeding the success criteria set at 60% by a panel of HCPs and patients. This, however, declined to 51% at six months. Eight patients (6.7%) died (all cardiovascular deaths), four (3.3%) had a major lower limb amputation, 12 (10%) had a cardiovascular event, and 13 (11%) were admitted due to limb ischaemia at six months. Incomplete lipid therapy prescriptions and LEGS intervention documents not received by primary care CHPs were the most common reasons for not complying with the LEGS intervention. Conclusions: The LEGS intervention can be delivered in PAD care pathways across different hospitals, primary, and community healthcare settings with acceptable fidelity, to streamline and improve PAD BMT short- and medium-term.

Use of the Off-The-Shelf Pre-Cannulated E-Nside Endograft to Overcome Anatomical Challenges in Urgent Complex Endovascular Aortic Repair.

Treatment options for large or symptomatic complex aortic aneurysms that require urgent intervention remain limited. Patient factors and comorbidities often make open surgery unappealing, leading to increasing interest in endovascular solutions that can be employed in the urgent setting, such as off-the-shelf endografts. The E-nsideTM (Jotec GmbH, Hechingen, Germany) is a new off-the-shelf endograft with 4 pre-cannulated inner branches that has recently become available in Europe. We report the urgent treatment of 2 large complex aortic aneurysms using this device and discuss the benefits of this new technology. The E-nside off-the-shelf endograft with inner branches is a useful addition to our treatment options for complex aortic aneurysms, particularly those with a narrow aortic lumen. Pre-cannulation of branches provides consistent access to the branches and a readily available option for establishment of a through and through wire for added stability during cannulation and bridging stent-grafts placement. The design of inner branches provides flexibility during deployment of the endograft and cannulation of the target vessels in varied, challenging anatomies.

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

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

Medium-term outcomes after inferior vena cava reconstruction for acute and chronic deep vein thrombosis and retroperitoneal fibrosis.

OBJECTIVE: In the present study, we evaluated the technical and clinical outcomes after endovascular inferior vena cava (IVC) reconstruction in patients with nonmalignant obstruction. METHODS: The preoperative, procedural, and follow-up medical records and imaging studies were retrospectively reviewed for 59 consecutive patients who had undergone endovascular IVC reconstruction for nonmalignant obstruction from February 2014 to January 2019. The patients were classified into three groups according to the quality of their infrainguinal inflow vessels. The outcomes measured were the primary, primary-assisted, and secondary patency rates, reintervention rates, and symptomatic resolution. RESULTS: The indications for treatment were post-thrombotic syndrome (n = 41), acute deep vein thrombosis (n = 12), and retroperitoneal fibrosis (n = 6). The median patient age was 37 years, 11 months, 71.2% were men, and 32.2% had a diagnosis of thrombophilia, with no significant difference in these demographics between the three inflow groups. The median follow-up duration was 2 years, 3 months (range, 6 months to 6 years, 5 months). The whole-cohort primary patency was 91.2%, 71.0%, and 24.1% at 1, 3, and 5 years, respectively. Secondary patency was 76.7% at 1 year and 66.4% at both 3 and 5 years. Inflow group A (no post-thrombotic disease in the femoral or deep femoral veins) demonstrated significantly higher primary patency compared with group B (stenotic disease in one or two infrainguinal inflow veins; P = .009) and significantly higher secondary patency than for both groups B (P = .008) and C (all three infrainguinal inflow veins had stenosed or femoral and/or deep femoral vein occlusion was present; P = .04). In post-thrombotic syndrome patients, the Villalta scores had decreased from a mean of 14.2 to 8.1 at 1 year and 6.8 at 2 years, and the Venous Insufficiency Epidemiological and Economic Study Quality of Life score had improved from a mean of 19.8 to 54.1 and 57.3 at 1 and 2 years, respectively. In the patients with acute deep vein thrombosis, the Villalta score was 2.8 at 1 year and 0 at 2 years. In the patients with retroperitoneal fibrosis, the Venous Insufficiency Epidemiological and Economic Study Quality of Life score had improved from a mean of 25.3 at baseline to 44 at 6 months. CONCLUSIONS: Endovascular IVC reconstruction for nonmalignant obstruction can achieve good patency and clinical improvement, although the outcomes were poorer for patients with post-thrombotic disease of the femoral and deep femoral veins.