Outcomes from a tertiary care center using a catheter thrombectomy system for managing acute iliofemoral deep vein thrombosis.

OBJECTIVE: The aim of the present study was to report a large, single-center experience using the ClotTriever thrombectomy system (Inari Medical, Irvine, CA) for the management of acute iliofemoral (IF) deep vein thrombosis (DVT). One limitation of all endovascular devices for the treatment of acute IF-DVT has been the inability to completely remove all acute thrombus and the need for adjunctive thrombolysis with its attendant risk of bleeding complications. METHODS: A single-center retrospective review of consecutive patients with acute IF-DVT treated with the ClotTriever thrombectomy system (Inari Medical) is reported. Procedural efficacy was evaluated by an independent core imaging laboratory (Syntactx, New York, NY). Both procedural and in-hospital safety were assessed during the index hospitalization. The treated vein patency was assessed using duplex ultrasound at 30 days after the procedure. RESULTS: A total of 96 patients were included in the present retrospective review, 40 of whom (40%) had contraindications to thrombolytic therapy. In terms of efficacy, 93 patients (97%) had ≥75% thrombus removal. During the index hospitalization, two patients (2%) had experienced a symptomatic pulmonary embolus. However, no mortality, major bleeding, or device-related complications had occurred in the study population. Of the 96 patients, 64 had undergone duplex ultrasound at 30 days after the procedure. Of the 64 patients, 62 had normal flow (97%), 53 (83%) had normal compressibility, and 11 (17%) had partial compressibility. CONCLUSIONS: The ClotTriever thrombectomy catheter was both safe and effective in our cohort of patients with acute IF-DVT outside a randomized clinical trial.

Histopathologic analysis of extracted thrombi from deep venous thrombosis and pulmonary embolism: Mechanisms and timing.

BACKGROUND: Mechanical thrombectomy is increasingly being used as an alternative to pharmacologic therapies for the treatment of patients with acute deep venous thrombosis (DVT) and pulmonary embolism (PE) and allows direct histopathologic comparison of thrombi extracted from living patients. We performed histopathologic analysis to thrombi extracted from cases of DVT and PE to gain insights into their relative cellular compositions. METHODS: Thrombus retrieved using a catheter-based thrombectomy system (ClotTriever for lower extremity DVT and FlowTriever for PE) from the 17 patients (7 DVT cases and 10 PE cases) were histologically evaluated. Histological features were used to estimate their age and pathological characteristics. RESULTS: The thrombus in all cases were composed of fibrin, platelets, red blood cells, and acute inflammatory cells. The weights of thrombus obtained from DVT versus PE cases were heavier (DVT 7.2 g (g) (5.6-10.2) vs. PE 4.8 g (3.6-6.8), p = .01). Overall thrombus healing (i.e., thrombus composed of smooth muscle cells, endothelial cells, and proteoglycans) was different between DVT and PE cases. 6/7 (86%) with features of late stage healing were from DVT cases while only three of ten (30%) were from PE cases while PE contained more acute thrombi with 7/10 (70%) stage 2 as compared 1/7 (14%) for DVT (p = .0498). CONCLUSION: This study is the first to directly compare the histology of extracted thrombus in DVT versus PE cases from patients with clinical events. Overall PE cases demonstrated significantly earlier stage thrombus with a larger component of red blood cells.

Outcomes of endovascular venous stenting in patients on direct oral anticoagulants and antiplatelet therapy at a tertiary referral center.

BACKGROUND: Endovenous revascularization is the standard in the management of acute thrombotic, chronic post-thrombotic iliocaval or iliofemoral obstruction, and nonthrombotic iliac vein lesions. The purpose of this study is to describe our single-center experience of postprocedure anticoagulation and antiplatelet regimens used after endovenous revascularization for a variety of venous occlusive conditions. METHODS: We conducted a retrospective analysis of 100 consecutive patients who underwent endovenous stenting for iliocaval or iliofemoral obstruction from January 1, 2014, to April 30, 2018. Patients treated with direct oral anticoagulants, warfarin, or low-molecular-weight heparin (LMWH) with or without antiplatelet therapy were identified. Demographic, procedural, patency, and follow-up data were collected. Stent patency was evaluated using duplex Doppler ultrasound examination or contrast venography. RESULTS: Seventy-one of 100 patients were treated with direct oral anticoagulant therapy (DOAC). Sixteen (23%) were lost to follow-up, leaving 55 (77%) available for analysis. The mean follow-up was 14 months (range, 1-43 months) with 32 patients (58%) followed for 12 months or longer. Primary, primary-assisted, and secondary-assisted patency rates were 87%, 97%, and 98%, respectively, at 12 months. In the non-DOAC group (patients treated with warfarin or LMWH), these rates were 87%, 93%, and 95%, respectively, at 12 months. Antiplatelet therapy, including clopidogrel, aspirin, or both, was used in 53 of 55 patients in the DOAC cohort and 18 of 19 patients in the non-DOAC group. CONCLUSIONS: Our-single center retrospective analysis demonstrates acceptable primary patency rates when using DOAC therapy compared with those treated with warfarin or LMWH.

Pulmonary Embolism: Current Role of Catheter Treatment Options and Operative Thrombectomy.

Pulmonary embolism remains a leading cause of death in the United States, with an estimated 180,000 deaths per year. Guideline-based treatment in most cases recommends oral anticoagulation for 3 months. However, in a small subset of patients, the "submassive, high-risk" by current nomenclature, with hemodynamic instability, more advanced therapeutic options are available. Treatment modalities to extract the thromboembolism and reduce pressure overload in the cardiopulmonary system include use of intravenous or catheter-directed thrombolytic agents, catheter-directed mechanical thrombectomy, and surgical embolectomy. This article discusses current minimally invasive and surgical methods for reducing embolic burden in patients with submassive, high-risk pulmonary embolism.

Surface-Engineered Blood Adsorption Device for Hyperphosphatemia Treatment.

Correspondence: Melanie S. Joy, PharmD, PhD, University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, Department of Pharmaceutical Sciences, Mail Stop C238, Room V20-4108, 12850 East Montview Blvd, Aurora, CO 80045. Email: Melanie.Joy@ucdenver.edu The research employed surface engineering methods to develop, optimize, and characterize a novel textile-based hemoadsorption device for hyperphosphatemia in hemodialysis-dependent end-stage kidney disease. Phosphate adsorbent fabrics (PAFs) were prepared by thermopressing alumina powders to polyester filtration fabrics and treatment with trimesic acid (TMA). For static experiments, phosphate adsorption capacity in buffer solution, plasma, and blood were evaluated by submersing the PAFs in 100 ml. For dynamic experiments, PAFs were equipped in a device prototype and incorporated in a pump-driven circuit. Phosphates were determined by a colorimetric assay and an Ortho Clinical Diagnostics Vitros 5600 Integrated analyzer. The maximum loading amount of TMA-alumina on PAFs was approximately 35 g/m under 260°C processing temperature. Phosphate adsorption capacity increased with initial concentration. Adsorption isotherms from buffer demonstrated a maximum phosphate adsorption capacity of approximately 893 mg/m at 37.5°C, pH 7.4, with similar results from plasma and whole blood. Measured phosphate concentrations during simulations demonstrated a 42% reduction, confirming the high capacity of the PAFs for removing phosphate from whole blood. Results from the current study indicated that an alumina-TMA treated PAF can dramatically reduce phosphate concentrations from biological samples. The technology could potentially be used as a tunable adsorbent for managing hyperphosphatemia in kidney disease.

Impact of exercise on heart rate recovery.

BACKGROUND: Abnormal heart rate recovery (HRR) has been shown to predict mortality. Although small studies have found that HRR can be improved with cardiac rehabilitation, it is unknown whether an improvement would affect mortality. The aim of this study was to determine whether HRR could be improved with cardiac rehabilitation and whether it would be predictive of mortality. METHODS AND RESULTS: We evaluated 1070 consecutive patients who underwent exercise stress testing before and after completion of a phase 2 cardiac rehabilitation program. Heart rate recovery, defined as the difference between heart rate at peak exercise and exactly 1 minute into the recovery period, and mortality were followed up as the primary end points. Of 544 patients with abnormal baseline HRR, 225 (41%) had normal HRR after rehabilitation. Of the entire cohort, 197 patients (18%) died. Among patients with an abnormal HRR at baseline, failure to normalize after rehabilitation predicted a higher mortality (P<0.001). After multivariable adjustment, the presence of an abnormal HRR at exit was predictive of death in all patients (hazard ratio, 2.15; 95% confidence interval 1.43-3.25). Patients with abnormal HRR at baseline who normalized afterward had survival rates similar to those of the group with normal HRR at baseline and after cardiac rehabilitation (P=0.143). CONCLUSIONS: Heart rate recovery improved after phase 2 cardiac rehabilitation in the overall cohort. There was a strong association of abnormal HRR at exit with all-cause mortality. Patients with abnormal HRR at baseline who normalized HRR with exercise had a mortality similar to that of individuals with baseline normal HRR.