A comparative study of altered hemodynamics in iliac vein compression syndrome.

Introduction: Iliac vein compression syndrome (IVCS) is present in over 20% of the population and is associated with left leg pain, swelling, and thrombosis. IVCS symptoms are thought to be induced by altered pelvic hemodynamics, however, there currently exists a knowledge gap on the hemodynamic differences between IVCS and healthy patients. To elucidate those differences, we carried out a patient-specific, computational modeling comparative study. Methods: Computed tomography and ultrasound velocity and area data were used to build and validate computational models for a cohort of IVCS (N = 4, Subject group) and control (N = 4, Control group) patients. Flow, cross-sectional area, and shear rate were compared between the right common iliac vein (RCIV) and left common iliac vein (LCIV) for each group and between the Subject and Control groups for the same vessel. Results: For the IVCS patients, LCIV mean shear rate was higher than RCIV mean shear rate (550 ± 103 s-1 vs. 113 ± 48 s-1, p = 0.0009). Furthermore, LCIV mean shear rate was higher in the Subject group than in the Control group (550 ± 103 s-1 vs. 75 ± 37 s-1, p = 0.0001). Lastly, the LCIV/RCIV shear rate ratio was 4.6 times greater in the Subject group than in the Control group (6.56 ± 0.9 vs. 1.43 ± 0.6, p = 0.00008). Discussion: Our analyses revealed that IVCS patients have elevated shear rates which may explain a higher thrombosis risk and suggest that their thrombus initiation process may share aspects of arterial thrombosis. We have identified hemodynamic metrics that revealed profound differences between IVCS patients and Controls, and between RCIV and LCIV in the IVCS patients. Based on these metrics, we propose that non-invasive measurement of shear rate may aid with stratification of patients with moderate compression in which treatment is highly variable. More investigation is needed to assess the prognostic value of shear rate and shear rate ratio as clinical metrics and to understand the mechanisms of thrombus formation in IVCS patients.

A mapping review of Pacific Vascular Symposium 6 initiatives.

OBJECTIVE: The 2010 Pacific Vascular Symposium 6 (PVS6) brought venous disease content experts together with a goal of addressing critical issues collated together in the next decade with concrete plans to achieve these goals. This mapping review aims to provide a broader representation of how progress in critical issues of chronic venous disease has been made by extrapolating scientific publications related to the PVS6 initiatives. METHODS: We performed a mapping review identifying original or systematic review/meta-analysis articles related to PVS 6 initiatives (aims) that addressed one of the following key objectives: scales to measure chronic venous disease, effectiveness of interventional deep venous thrombus removal, development of a deep venous valve, and biomarkers related to venous disease. Searches were undertaken in PubMed, Ovid Medline, Cochrane Library, Embase (Elsevier), CINAHL (EBSCO), and Scopus. We extracted descriptive information about the studies and predefined variables for each specific aim, showing what and where research exists on the aims included. RESULTS: A total of 2138 articles were screened from 3379 retrieved articles from six electronic databases. We mapped 186 included articles, finding that the total number of publications significantly increased after the 2010 PVS6 meeting. Aim results were visually summarized. The largest body of data addressed catheter-based thrombus removal strategies for acute iliofemoral deep venous thrombosis. Primary research on artificial venous valves and venous biomarkers remained limited. No new post-thrombotic syndrome (PTS) score has been developed. CONCLUSIONS: This mapping review identified and characterized the available evidence and gaps in our knowledge of chronic venous disease that exist visually, which may guide where more significant investments for the future should be targeted.

Saphenous vein aneurysms characterization and treatment: A 36-year single center experience.

BACKGROUND: Superficial vein aneurysms (SVA) are rare vascular pathologies associated with trauma, chronic venous disease, and venous malformation. METHOD: We retrospectively reviewed cases of SVA treated from 1986 to 2022. RESULTS: Out of 2463 venous procedures, 16 patients were found with 19 GSV and 1 SSV aneurysms, with 88% presenting with a palpable mass. Varicose veins were noted in 94% of patients, 81% had concomitant reflux, 15% had thrombus within the aneurysm sac, and 19% demonstrated multiple aneurysms. All patients underwent ligation and excision. Post-procedure, 55% of patients received anticoagulants, and 85% received compression. Mean follow-up was 19.4 months, with no aneurysm recurrence. We propose a modification to the current SVA classification. CONCLUSION: The prevalence of multiple aneurysms suggests the need for complete limb imaging in affected patients. Surgical management of SVA was effective in preventing SVA recurrence, while the proposed classification modification will aid in future SVA management.

An ultrasound imaging and computational fluid dynamics protocol to assess hemodynamics in iliac vein compression syndrome.

OBJECTIVE: Elevated shear rates are known to play a role in arterial thrombosis; however, shear rates have not been thoroughly investigated in patients with iliac vein compression syndrome (IVCS) owing to imaging limitations and assumptions on the low shear nature of venous flows. This study was undertaken to develop a standardized protocol that quantifies IVCS shear rates and can aid in the diagnosis and treatment of patients with moderate yet symptomatic compression. METHODS: Study patients with and without IVCS had their iliac vein hemodynamics measured via duplex ultrasound (US) at two of the following three vessel locations: infrarenal inferior vena cava (IVC), right common iliac vein, and left common iliac vein, in addition to acquiring data at the right and left external iliac veins. US velocity spectra were multiplied by a weighted cross-sectional area calculated from US and computed tomography (CT) data to create flow waveforms. Flow waveforms were then scaled to enforce conservation of flow across the IVC and common iliac veins. A three-dimensional (3D), patient-specific model of the iliac vein anatomy was constructed from CT and US examination. Flow waveforms and the 3D model were used as a basis to run a computational fluid dynamics (CFD) simulation. Owing to collateral vessel flow and discrepancies between CT and US area measurements, flows in internal iliac veins and cross-sectional areas of the common iliac veins were calibrated iteratively against target common iliac flow. Simulation results on mean velocity were validated against US data at measurement locations. Simulation results were postprocessed to derive spatial and temporal values of quantities such as velocity and shear rate. RESULTS: Using our modeling protocol, we were able to build CFD models of the iliac veins that matched common iliac flow splits within 2% and measured US velocities within 10%. Proof-of-concept analyses (1 subject, 1 control) have revealed that patients with IVCS may experience elevated shear rates in the compressed left common iliac vein, more typical of the arterial rather than the venous circulation. These results encourage us to extend this protocol to a larger group of patients with IVCS and controls. CONCLUSIONS: We developed a protocol that obtains hemodynamic measurements of the IVC and iliac veins from US, creates patient-specific 3D reconstructions of the venous anatomy using CT and US examinations, and computes shear rates using calibrated CFD methods. Proof-of-concept results have indicated that patients with IVCS may experience elevated shear rates in the compressed left common iliac vein. Larger cohorts are needed to assess the relationship between venous compression and shear rates in patients with IVCS as compared with controls with noncompressed iliac veins. Further studies using this protocol may also give promising insights into whether or not to treat patients with moderate, yet symptomatic compression.

Thromboembolic outcomes are decreased with the use of a standardized venous thromboembolism risk assessment and prophylaxis protocol for patients undergoing superficial venous procedures.

OBJECTIVE: Patients with venous insufficiency can be treated with ablation or phlebectomy, or both. Patients undergoing superficial venous procedures have an elevated risk of deep vein thrombosis (DVT) and pulmonary embolism (PE). At our institution, we initiated a standardized protocol in which patients with a Caprini score (2005 version) of ≥8 are treated with 1 week of prophylactic anticoagulation after the procedure. Duplex ultrasound was performed at 1 week and then within 90 days after the procedure. This aim of the present study was to determine the thrombotic and clinical outcomes after superficial vein procedures using a standardized protocol for DVT/PE risk assessment and prophylaxis. METHODS: We performed a retrospective analysis of prospectively collected data of superficial vein procedures from 2015 to 2021 at a single center. The patient demographics, CEAP (Clinical-Etiology-Anatomy-Pathophysiology) clinical class, venous clinical severity score, patient-reported outcomes, treatment type, Caprini scores, pre- and postoperative anticoagulation use, and outcomes were collected. Descriptive statistics were used for the patient demographics, procedure details, and unadjusted surgical outcomes. Multivariable logistic regression was used to evaluate the relationship between procedure type and DVT and PE after adjusting for patient characteristics, disease severity, periprocedural anticoagulation, and Caprini score. RESULTS: A total of 1738 limbs were treated with ablation (n = 820), phlebectomy (n = 181), or ablation and phlebectomy (n = 737). More patients were women (67.1%) and White (90.9%). The overall incidence of DVT/PE was 1.4%. Patients undergoing ablation with phlebectomy had higher rates of DVT/PE (2.7%) than those undergoing ablation (0.2%) or phlebectomy alone (1.7%; P < .01). However, only 30% of DVTs were above the knee. On multivariate analysis, only the procedure type predicted for DVT/PE. However, patients undergoing ablation and phlebectomy achieved better patient-reported outcomes (Caprini score, 5.9) compared with those undergoing ablation (Caprini score, 7.2) or phlebectomy (Caprini score, 7.9) alone (P < .01). The best improvement in the venous clinical severity score was seen with phlebectomy alone. CONCLUSIONS: The expected difference in the DVT/PE rates between high- and low-risk groups did not materialize in our patients, perhaps secondary to the additional chemoprophylaxis prescribed for the high-risk cohort (Caprini score, ≥8). These results call for a randomized trial to assess the efficacy of a standardized protocol in the reduction of DVT/PE after superficial vein procedures.

The histone methyltransferase MLL1/KMT2A in monocytes drives coronavirus-associated coagulopathy and inflammation.

Coronavirus-associated coagulopathy (CAC) is a morbid and lethal sequela of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. CAC results from a perturbed balance between coagulation and fibrinolysis and occurs in conjunction with exaggerated activation of monocytes/macrophages (MO/Mφs), and the mechanisms that collectively govern this phenotype seen in CAC remain unclear. Here, using experimental models that use the murine betacoronavirus MHVA59, a well-established model of SARS-CoV-2 infection, we identify that the histone methyltransferase mixed lineage leukemia 1 (MLL1/KMT2A) is an important regulator of MO/Mφ expression of procoagulant and profibrinolytic factors such as tissue factor (F3; TF), urokinase (PLAU), and urokinase receptor (PLAUR) (herein, "coagulopathy-related factors") in noninfected and infected cells. We show that MLL1 concurrently promotes the expression of the proinflammatory cytokines while suppressing the expression of interferon alfa (IFN-α), a well-known inducer of TF and PLAUR. Using in vitro models, we identify MLL1-dependent NF-κB/RelA-mediated transcription of these coagulation-related factors and identify a context-dependent, MLL1-independent role for RelA in the expression of these factors in vivo. As functional correlates for these findings, we demonstrate that the inflammatory, procoagulant, and profibrinolytic phenotypes seen in vivo after coronavirus infection were MLL1-dependent despite blunted Ifna induction in MO/Mφs. Finally, in an analysis of SARS-CoV-2 positive human samples, we identify differential upregulation of MLL1 and coagulopathy-related factor expression and activity in CD14+ MO/Mφs relative to noninfected and healthy controls. We also observed elevated plasma PLAU and TF activity in COVID-positive samples. Collectively, these findings highlight an important role for MO/Mφ MLL1 in promoting CAC and inflammation.

Contemporary management and outcomes of peripheral venous aneurysms: A multi-institutional study.

OBJECTIVE: Extremity venous aneurysms result in the risk of pulmonary embolism (PE) and chronic venous insufficiency. At present, owing to the rarity of these aneurysms, no consensus for their treatment has been established. The purpose of the present study was to review the presentation, natural history, and contemporary management of extremity venous aneurysms. METHODS: We performed a retrospective, multi-institutional review of all patients with extremity venous aneurysms treated from 2008 to 2018. A venous aneurysm was defined as saccular or fusiform with an aneurysm/vein ratio of >1.5. RESULTS: A total of 66 extremity aneurysms from 11 institutions were analyzed, 40 of which were in a popliteal location, 14 iliofemoral, and 12 in an upper extremity or a jugular location. The median follow-up was 27 months (range, 0-120 months). Of the 40 popliteal venous aneurysms, 8 (20%) had presented with deep vein thrombosis (DVT) or PE, 13 (33%) had presented with pain, and 19 had been discovered incidentally. The mean size of the popliteal venous aneurysms presenting with DVT or PE was larger than that of those presenting without thromboembolism (3.8 cm vs 2.5 cm; P = .003). Saccular aneurysm morphology in the lower extremity was associated with thromboembolism (30% vs 9%; P = .046) and fusiform aneurysm morphology with a thrombus burden >25% (45% vs 3%). Patients presenting with thromboembolism were more likely to have had a thrombus burden >25% in their lower extremity venous aneurysm compared with those who had presented without thromboembolism (70% vs 9%). Approximately half of all the patients underwent immediate intervention, and half were managed with observation or antithrombotic regimen. In the non-operative cohort, three patients subsequently developed a DVT. Eight patients in the medically managed cohort went on to require surgical intervention. Of the 12 upper extremity venous aneurysms, none had presented with DVT or PE, and only 2 (17%) had presented with pain. Of the 66 patients in the entire cohort, 41 underwent surgical intervention. The most common indication was the absolute aneurysm size. Nine patients had undergone surgery because of a DVT or PE, and 11 for pain or extremity swelling. The most common surgery was aneurysmorrhaphy in 21 patients (53%), followed by excision and ligation in 14 patients (35%). Five patients (12%) had undergone interposition bypass grafting. A postoperative hematoma requiring reintervention was the most common complication, occurring in three popliteal vein repairs and one iliofemoral vein repair. None of the patients, treated either surgically or medically, had reported post-thrombotic complications during the follow-up period. CONCLUSIONS: Large lower extremity venous aneurysms and saccular aneurysms with thrombus >25% of the lumen are more likely to present with thromboembolic complications. Surgical intervention for lower extremity venous aneurysms is indicated to reduce the risk of venous thromboembolism (VTE) and the need for continued anticoagulation. Popliteal aneurysms >2.5 cm and all iliofemoral aneurysms should be considered for repair. Upper extremity aneurysms do not have a significant risk of VTE and warrant treatment primarily for symptoms other than VTE.

Women benefit from endovenous ablation with fewer complications: Analysis of the Vascular Quality Initiative Varicose Vein Registry.

OBJECTIVE: To evaluate the association between gender and long-term clinician-reported and patient-reported outcomes after endovenous ablation procedures. METHODS: This retrospective cohort study of prospectively collected data from the Vascular Quality Initiative's Varicose Vein Registry included patients undergoing endovenous ablation procedures on truncal veins with or without treatment of perforating veins between 2015 and 2019. A univariate analysis included comparisons of preprocedural, postprocedural, and periprocedural change in Venous Clinical Severity Score (VCSS) and total symptom score by gender. Rates of complications including deep vein thrombosis, endovenous heat-induced thrombosis, leg pigmentation, blistering, paresthesia, incisional infection, and any postprocedural complications were reported by gender. Multivariable analysis leveraged linear regression to examine how gender affected the relationships between patient characteristics, complication rates, and periprocedural change in VCSS score and total symptom score. RESULTS: Of 9743 patients who met the inclusion criteria, 3090 (31.7%) were men and 6653 (68.2%) were women. The perioperative change in VCSS score was greater for men than women (average -4.46 for men vs -4.13 for women; P < .0001). Perioperative change in total symptom score was greater for women than for men (average -10.64 for women vs -9.64 for men; P < .0001). Women had lower incidence of any leg complication (6.1% vs 8.6%; P = .001) endovenous heat-induced thrombosis (1.1% vs 2.2%; P = .002), and infection (0.4% vs 0.7%; P = .001). In multivariable analysis, among patients with a body mass index of more than 40, presence of deep reflux, and preoperative Clinical, Etiologic, Anatomic, and Physiologic classification of 2, women had a greater periprocedural change in VCSS score than men. CONCLUSIONS: Women benefited from endovenous ablation similarly as men, with a lower incidence of postprocedural complications. Gender may be useful for patient selection and counseling for endovenous ablation, with particular usefulness among patients with a high body mass index, presence of deep reflux, and preoperative Clinical, Etiologic, Anatomic, and Physiologic classification of 2.

Treatment and contemporary outcomes associated with adjunct tourniquet use during phlebectomy of complex, voluminous truncular varicosities.

OBJECTIVE: Phlebectomy of large voluminous varicose veins comes with a risk of substantial blood loss. The purpose of the present study was to investigate the outcomes associated with the use of an adjunct tourniquet during varicose vein surgery of complex and large truncular varicosities. METHODS: The prospectively collected registry data included anatomic and outcomes details for patients who presented with complex and large truncular varicosities with a CEAP clinical class of C2, or higher (indicating more serious venous disease) from December 2014 to December 2021. Of all patients, those treated with an adjunct tourniquet for large complex varicosities (largest diameter varicosity ≥1 cm by visual inspection) were selected for analysis. The venous clinical severity scores (VCSSs) and patient-reported outcomes (PROs) were obtained. Additional parameters, including operative time, tourniquet time, and blood loss, were obtained retrospectively via a review of the medical records. Univariate descriptive statistics of the demographic and procedural data were performed pre- and postoperatively, with comparisons performed using the Student two-tailed t test. RESULTS: The data from 19 patients (22 limbs; 7 women and 12 men) were analyzed. Of the 22 limbs, 11 (50%) had advanced venous disease of C4 or higher preoperatively. A review of the preoperative duplex ultrasound scans confirmed the presence of large varicosities (average, 1.0 ± 0.54 cm; n = 18). All the limbs were treated using radiofrequency ablation of axial reflux and phlebectomy (a combination of powered and stab) under tourniquet control (82%) or phlebectomy under tourniquet control alone (18%). The average tourniquet time was 40 ± 12 minutes, with a median blood loss of 50 mL (interquartile range, 30-100 mL). The average follow-up was 332 ± 422 days after 19 procedures for 16 patients (2 patients moved out of state during the immediate postoperative period and 1 patient was lost to follow-up). Of the patients who completed >3 months of follow-up, 14 limbs experienced improvement in the CEAP class, 5 limbs had no change, and 3 were limbs of patients who moved or were lost to follow-up. The VCSSs significantly improved (8.8 ± 2.8 vs 3.9 ± 1.9; P < .0001). The PROs also improved significantly (16.1 ± 5.0 vs 2.2 ± 2.3; P < .0001). CONCLUSIONS: Tourniquet use in the treatment of varicosities has only been described in the setting of high ligation and stripping. Our data suggest that in the modern era of minimally invasive endovenous treatment of axial reflux and phlebectomy, adjunct tourniquet use during the treatment of large complex varicosities can result in significant improvements in the VCSSs and PROs, with minimal blood loss.

P- and E- selectin in venous thrombosis and non-venous pathologies.

Venous thromboembolism is a very common and costly health problem worldwide. Anticoagulant treatment for VTE is imperfect: all have the potential for significant bleeding, and none prevent the development of post thrombotic syndrome after deep vein thrombosis or chronic thromboembolic pulmonary hypertension after pulmonary embolism. For these reasons, alternate forms of therapy with improved efficacy and decreased bleeding are needed. Selectins are a family (P-selectin, E-selectin, L-selectin) of glycoproteins that facilitate and augment thrombosis, modulating neutrophil, monocyte, and platelet activity. P- and E-selectin have been investigated as potential biomarkers for thrombosis. Inhibition of P-selectin and E-selectin decrease thrombosis and vein wall fibrosis, with no increase in bleeding. Selectin inhibition is a promising avenue of future study as either a stand-alone treatment for VTE or as an adjunct to standard anticoagulation therapies.

E-selectin inhibitor is superior to low-molecular-weight heparin for the treatment of experimental venous thrombosis.

BACKGROUND: This study evaluated E-selectin inhibition with GMI-1271 (Uproleselan [GMI]) alone and in combination with the standard of care low-molecular-weight heparin (LMWH) to improve vein recanalization, decrease vein wall inflammation and protect against adverse bleeding in a primate model. We sought to examine this novel treatment of venous thrombosis. METHODS: Using a well-documented primate animal model, iliac vein thrombosis was induced by balloon occlusion of the iliac vein for 6 hours. Starting on day 2 after thrombosis, animals began treatment in two phases. In phase one, nontreated controls received no treatment (n = 5) vs animals treated with the E-selectin inhibitor GMI, 25 mg/kg, subcutaneous (SC), once daily (n = 4) for 21 days (previously published data). In phase two, animals were treated with GMI plus a combination of LMWH 1.5 mg/kg or 40 mg (GMI + LMWHc) SC once daily (n = 8) for 19 days; and animals treated with LMWH 1.5 mg/kg or 40 mg (LMWHc) SC once daily (n = 6) for 19 days. Animals were evaluated by magnetic resonance venography for vein recanalization and inflammation by gadolinium extravasation, duplex ultrasound, coagulation tests (thromboelastography, bleeding time, prothrombin time, activated partial thromboplastin time, fibrinogen) and complete blood count at baseline, days 2, 7, 14, and 21 at euthanasia. Statistical analysis included using unpaired t test with Welch's correction for direct comparisons and one-way analysis of variance for comparison between the groups. RESULTS: Percent vein recanalization by magnetic resonance venography was highest in the GMI alone group followed by GMI + LMWHc, both significantly different from control. On ultrasound examination, animals treated with GMI alone had no decrease in open vein lumen by day 21, whereas decreases were observed in groups GMI + LMWHc (-26%), LMWHc (-27%), and controls (-80%). Vein wall inflammation decreased significantly in all treated groups. Intimal fibrosis and intimal thickness was best preserved in the GMI alone group. An analysis of total vein wall collagen revealed a trend in all treatment groups of decreasing vein wall collagen. No clinically significant bleeding events were noted in any group. The LMWH groups trended to have prolonged coagulation test values, whereas E-selectin inhibition with GMI did not cause clinically significant changes in coagulation measures. CONCLUSIONS: Treatment with E-selectin inhibition results in improved vein recanalization, a decrease in vein wall inflammation and vein wall intimal thickness and fibrosis, with no changes in markers of coagulation. E-selectin inhibition with GMI alone is superior to E-selectin inhibition combined with LMWH, LMWH alone, and no treatment in this deep vein thrombosis model of iliac vein thrombosis.

Low to Moderate Risk Non-orthopedic Surgical Patients Do Not Benefit From VTE Chemoprophylaxis.

This retrospective cohort study analyzes venous thromboembolism (VTE) incidence, morbidity, and mortality amongst postsurgical patients with and without VTE chemoprophylaxis within a quality collaborative. Postoperative thromboprophylaxis was broadly applied, yet was associated with no decrease in VTE, without affecting transfusion or mortality. Predictors of breakthrough VTE development despite evidence-based thromboprophylaxis are identified. OBJECTIVE: We hypothesized that a high rate of prescription of VTE chemoprophylaxis would be associated with decreased VTE incidence and mortality. SUMMARY BACKGROUND DATA: Recommendations for VTE prevention in surgical patients include chemoprophylaxis based upon preoperative risk stratification. METHODS: This retrospective cohort study analyzed VTE incidence, morbidity, and mortality amongst postsurgical patients with and without VTE chemoprophylaxis between April 2013 and September 2017 from 63 hospitals within the Michigan Surgical Quality Collaborative. A VTE risk assessment survey was distributed to providers. Bivariate and multivariate comparisons were made, as well as using propensity score matched cohorts to determine if VTE chemoprophylaxis was associated with decreased VTE events. Hospitals were compared using risk-reliability adjusted VTE prophylaxis and postoperative VTE event rates. RESULTS: Within the registry, 80% of practitioners reported performing formal VTE risk assessment. Amongst 32,856 operations, there were 480 (1.46%) postoperative VTE, and an overall mortality of 609 (1.85%) patients. Using a propensity matched cohort, we found that rates of VTE were similar in those receiving unfractionated heparin or low molecular weight heparin compared to those not receiving chemoprophylaxis (1.22 vs 1.13%, P = 0.57). When stratified further by VTE risk scoring, even the highest risk patients did not have an associated lower VTE rate (3.68 vs 4.22% P = 0.092). Postoperative transfusion (8.28 vs 7.50%, P = 0.057) and mortality (2.00% vs 1.62%, P = 0.064) rates were similar amongst those receiving and those not receiving chemoprophylaxis. No correlation was found between postoperative VTE chemoprophylaxis application and hospital specific risk adjusted postoperative VTE rates. CONCLUSIONS: In modern day postsurgical care, VTE remains a significant occurrence, despite wide adoption of VTE risk assessment. Although postoperative VTE chemoprophylaxis was broadly applied, after adjusting for confounders, no reduction in VTE was observed in at-risk surgical patients.

A narrative review on the epidemiology, prevention, and treatment of venous thromboembolic events in the context of chronic venous disease.

OBJECTIVE: Chronic venous disease (CVD) describes a spectrum of conditions associated with venous hypertension. The association between various CVD etiologies and the subsequent risk of venous thromboembolism (VTE), such as deep vein thrombosis or pulmonary embolism, is a topic of considerable clinical interest. The aims of the present review were to characterize the risk of VTE according to the CVD etiology and to determine the optimal anticoagulation strategy for the treatment or prevention of VTE in patients with CVD. METHODS: An extensive search of the available surgical and medical data was conducted in PubMed and Google Scholar. We searched for the following terms and other related terms to identify relevant studies: CVD, chronic venous insufficiency, varicose veins, post-thrombotic syndrome (PTS), anticoagulation, venous thromboembolism, and venous disease scoring systems (eg, CEAP [clinical, etiology, anatomic, pathophysiology], Villalta, Ginsberg, venous clinical severity score). The identified studies included randomized control trials, retrospective and prospective observational studies, narrative and systematic reviews, case reports, and case series that contributed to the proposed aims. The ClinicalTrials.gov database was also queried to identify any relevant ongoing clinical trials. RESULTS: Congenital CVD carries a heightened risk of VTE, although few higher level studies are available to inform on this topic or on the appropriate anticoagulation strategies for these patients. Noncongenital CVD seems to carry a heightened risk of VTE, although few studies have adequately differentiated between primary and secondary etiologies. Varicose veins are a risk factor for primary VTE but might not be associated with an increased risk of recurrent VTE. In the hospital setting, patients with varicosities should be provided thromboprophylaxis. In the setting of varicose vein intervention, high-risk patients should be identified using risk assessment models and receive thromboprophylaxis. The risk of recurrent VTE in the setting of PTS is unclear but indefinite anticoagulation is not currently indicated. For patients with PTS, residual vein thrombosis might be an indicator of when anticoagulation can be safely stopped, although practical limitations to its application exist. CONCLUSIONS: CVD is associated with an increased risk of VTE. Few studies have differentiated between classes of CVD using a standardized method and have assessed the efficacy of anticoagulation prophylaxis against or treatment of VTE. Additional studies are needed to determine the optimal therapy for preventing and treating VTE in patients with active concurrent CVD.

Antisense oligonucleotides and nucleic acids generate hypersensitive platelets.

INTRODUCTION: Despite the great promise for therapies using antisense oligonucleotides (ASOs), their adverse effects, which include pro-inflammatory effects and thrombocytopenia, have limited their use. Previously, these effects have been linked to the phosphorothioate (PS) backbone necessary to prevent rapid ASO degradation in plasma. The main aim of this study was to assess the impact of the nucleic acid portion of an ASO-type drug on platelets and determine if it may contribute to thrombosis or thrombocytopenia. METHODS: Platelets were isolated from healthy donors and men with advanced prostate cancer. Effects of antisense oligonucleotides (ASO), oligonucleotides, gDNA, and microRNA on platelet activation and aggregation were evaluated. A mouse model of lung thrombosis was used to confirm the effects of PS-modified oligonucleotides in vivo. RESULTS: Platelet exposure to gDNA, miRNA, and oligonucleotides longer than 16-mer at a concentration above 8 mM resulted in the formation of hypersensitive platelets, characterized by an increased sensitivity to low-dose thrombin (0.1 nM) and increase in p-Selectin expression (6-8 fold greater than control; p < 0.001). The observed nucleic acid (NA) effects on platelets were toll-like receptor (TLR) -7 subfamily dependent. Injection of a p-Selectin inhibitor significantly (p = 0.02) reduced the formation of oligonucleotide-associated pulmonary microthrombosis in vivo. CONCLUSION: Our results suggest that platelet exposure to nucleic acids independent of the presence of a PS modification leads to a generation of hypersensitive platelets and requires TLR-7 subfamily receptors. ASO studies conducted in cancer patients may benefit from testing the ASO effects on platelets ex vivo before initiation of patient treatment.

Effect of concomitant deep venous reflux on truncal endovenous ablation outcomes in the Vascular Quality Initiative.

OBJECTIVE: Few studies have investigated outcomes after truncal endovenous ablation in patients with combined deep and superficial reflux and no studies have evaluated patient-reported outcomes. METHODS: We investigated the short- and long-term clinical and patient-reported outcomes among patients with and without deep venous reflux undergoing truncal endovenous ablation from 2015 to 2019 in the Vascular Quality Initiative. Preprocedural and postprocedural comparisons were performed using the t-test, χ2, or their nonparametric counterpart when appropriate. Multivariable logistic regression models were used to assess for confounding. RESULTS: A total of 4881 patients were included, of which 2254 (46.2%) had combined deep and superficial reflux. The median follow-up was 336.5 days. Patients with deep reflux were less likely to be female (65.9% vs 69.9%; P = .003), more likely to be Caucasian (90.2% vs 86.5%; P = .003) and had no difference in BMI (30.6 ± 7.5 vs 30.6 ± 7.2; P = .904). Additionally, no difference was seen in rates of prior varicose vein treatments, number of pregnancies, or history of deep venous thrombosis; however, patients without deep reflux were more likely to be on anticoagulation at the time of the procedure (10.9% vs 8.1%; P < .001). Patients without deep reflux had slightly higher median preprocedural Venous Clinical Severity Score (VCSS) scores (8 [interquartile range (IQR), 6-10]) vs 7 [IQR, 6-10]; P = .005) as well as postprocedural VCSS scores (5 [IQR, 3-7] vs 4 [IQR, 2-6]; P < .001). The median change in VCSS from before to after the procedure was lower for patients without deep reflux (3 [IQR, 1.0-5.5] vs 3.5 [IQR, 1-6]; P = .006). Total symptom score was higher for patients without deep reflux both before (median, 14 [IQR, 10-19] vs median, 13.5 [IQR, 9.5-18]; P = .005) and postprocedurally (median, 4 [IQR, 1-9] vs median, 3.25 [IQR, 1-7]; P < .001), but no difference was seen in change in symptom score (median, 8 [IQR, 4-13] vs median, 9 [IQR, 4-13]; P = .172). Patients with deep reflux had substantially higher rates of complications (10.4% vs 3.0%; P < .001), with a particular increase in proximal thrombus extension (3.1% vs 1.1%; P < .001). After controlling for confounding, this estimate of effect size for any complication increased (odds ratio, 5.72; 95% confidence interval, 2.21-14.81; P < .001). CONCLUSIONS: No significant difference is seen in total symptom improvement when patients undergo truncal endovenous ablation with concomitant deep venous reflux, although a greater improvement was seen in VCSS score in these patients. Patients with deep venous reflux had a significantly increased rate of complications, independent of confounding variables, and should be counseled appropriately before the decision for treatment.

Closed plication is a safe and effective method for treating popliteal vein aneurysm.

BACKGROUND: Popliteal vein aneurysms are a rare vascular anomaly first reported in the 1980s. Degeneration of elastic fibers and smooth muscle cell reduction, possibly secondary to inflammation, are implicated as integral steps in the development of these aneurysms. Given the rarity of this clinical entity, significant controversy exists regarding ideal treatment strategies, including the role of observation, medical management with anticoagulation, and surgical intervention. Retrospective reviews have demonstrated a failure rate of >40% with anticoagulation alone, with patients often presenting with pulmonary embolism. This has prompted our institutional preference for surgical management once the aneurysm is identified. Surgical management involves tangential repair with lateral venorrhaphy most commonly, followed in prevalence by aneurysm resection and end-to-end anastomosis either primarily or with vein interposition. Herein, we report our results with venous plications, through both closed and open techniques. METHODS: We performed a retrospective review of prospectively collected data for 10 patients undergoing popliteal vein plication for treatment of popliteal vein aneurysms. Patient-level characteristics and operative details were examined from periprocedural and follow-up records. RESULTS: We identified 10 patients undergoing popliteal vein plication, including 9 closed plications and 1 open plication. The average aneurysm size at presentation was 2.35 ± 0.69 cm for closed plication and 4.74 cm for the one open plication. After treatment, the average popliteal vein size was significantly reduced to 1.12 ± 0.45 cm for the closed plications (P < .001 from preprocedural size) and 1.13 cm for the open plication with 100% primary patency. Average follow-up for patients treated with closed plication was 35.0 ± 25.2 months, during which seven (78%) patients had a stable, normal popliteal vein size. One patient with recurrence was diagnosed with Klippel-Trénaunay syndrome. The other had degeneration of the popliteal vein cranial to the previous repair at 39 months after the original operation that required additional plication. The open plication patient experienced a hematoma requiring washout and resulting in a transient peroneal mononeuropathy. There was one case of cellulitis after closed plication but no hematomas within this group. CONCLUSIONS: Closed plication demonstrated favorable primary patency rates and low recurrence rates, avoiding technical issues or need for early institution of systemic anticoagulation associated with tangential repair and venorrhaphy or resection methods. Closed plication represents an attractive option in patients without luminal thrombus to limit the risk of these postoperative complications and obviates the need for bypass conduit and postoperative anticoagulation.