Xiaoqiang Li

Outcome of Endovascular Treatment in Postthrombotic Syndrome

BACKGROUND The postthrombotic syndrome (PTS) is a chronic complication of deep venous thrombosis (DVT) that is characterized by leg swelling and ulceration. METHODS Sixty-seven cases of PTS underwent attempted endovascular treatment with success in 63 between June 2005 and June 2012. Thirty-six cases underwent endovascular treatment only and 18 cases combined with temporary femoral arteriovenous fistula, 5 cases great saphenous vein ligation and stripping whereas 4 cases with communicating branch ligation around ulcers. RESULTS Stenting was successfully performed in 63 of 67 patients. The technical success rate was 94% with no mortality. Fifty-eight cases were followed up from 1 to 84 months. Stent occlusion or restenosis occurred in 17 patients. The primary and secondary patency rates were 87.9% and 93.1%, respectively, at 12 months and 70.7% and 82.8%, respectively, at 36 months. CONCLUSIONS Endovascular treatment of PTS is safe and effective. It can alleviate symptoms and prevent further deterioration of patients with PTS.

Downregulation of let-7e-5p contributes to endothelial progenitor cell dysfunction in deep vein thrombosis via targeting FASLG

This study aimed to evaluate the role of let-7e-5p in endothelial progenitor cells (EPCs) function and explore its therapeutic potential for deep vein thrombosis (DVT). We performed miRNAs screening and found that let-7e-5p was downregulated in DVT patients compared to control subjects. By using let-7e-5p agomir and antagomir, we demonstrated that let-7e-5p increased the migration and tube formation of human and rat EPCs. Based on bioinformatics, luciferase reporter assay and gene expression analysis, we identified Fas ligand (FASLG) as the target of let-7e-5p, and FASLG knockdown increased the migration and tube formation of EPCs. Furthermore, EPCs overexpressing let-7e-5p exhibited enhanced ability of homing and thrombus revascularization inrat model of venous thrombosis. In conclusion, let-7e-5p regulates the function of EPCs and is a potential therapeutic target in DVT treatment.

Autophagy protein 5 enhances the function of rat EPCs and promotes EPCs homing and thrombus recanalization via activating AKT

Deep venous thrombosis (DVT) is one of the most common peripheral vascular diseases. The roles of bone marrow-derived endothelial progenitor cells (EPCs) on the recanalization of venous thrombosis has been suggested recently, while the underlying mechanisms are not completely understood. Our objective was to investigate the functions of autophagy protein 5 (ATG5) in rat EPCs and its potential application in DVT. We have found that silencing of ATG5 or pharmacological suppression of ATG5 in rat EPCs reduces both the migration and psudotube formation under hypoxia in vitro. In line, overexpression of ATG5 significantly enhances the EPCs migration and psudotube formation capabilities. More importantly, injection of EPCs that stably express ATG5 increases EPC homing to the ischemic site and promotes thrombus recanalization in a rat DVT model in vivo. Mechanistically, we have shown that ATG5 overexpression enhances psudotube formation via the activation of AKT. These findings suggest that ATG5-AKT signaling plays an essential role in EPC migration and psudotube formation. Regulation of ATG5-AKT signaling may provide a potential novel therapy for DVT.

Mid-term outcome of endovascular treatment for acute lower extremity deep venous thrombosis

Purposes of the study To evaluate the benefit of stenting the iliac vein in patients with residual iliac vein stenosis treated with catheter-directed thrombolysis for acute iliofemoral deep venous thrombosis. Procedures In this randomized prospective study, patients with a first-time acute lower extremity deep venous thrombosis that had persisted <14 days were treated with catheter-directed thrombolysis. After catheter-directed thrombolysis, patients with >50% residual iliac vein stenosis were randomly divided into two groups: catheter-directed thrombolysis + Stent Group and catheter-directed thrombolysis Alone Group. Patients received urokinase thrombolysis and low-molecular-weight heparin/oral warfarin during the hospitalization period and were administrated oral warfarin after discharge. Cumulative deep vein patency, the Clinical Etiology Anatomic Pathophysiologic classification system, the Venous Clinical Severity Score and the Chronic Venous Insufficiency Questionnaire score were evaluated. Findings The cumulative deep vein patency rate was 74.07% in the catheter-directed thrombolysis + Stent Group and 46.59% in the catheter-directed thrombolysis Alone Group. The mean postoperative Clinical Etiology Anatomic Pathophysiologic classification and Venous Clinical Severity Score was significantly lower in the catheter-directed thrombolysis + Stent Group than in the catheter-directed thrombolysis Alone Group. The mean postoperative Chronic Venous Insufficiency Questionnaire score was significantly higher in the catheter-directed thrombolysis + Stent Group than the catheter-directed thrombolysis Alone Group. Conclusions Placement of an iliac vein stent in patients with residual iliac vein stenosis after catheter-directed thrombolysis for acute lower extremity deep venous thrombosis increases iliac vein patency and improves clinical symptoms and health-related quality of life at mid-term follow-up compared to patients treated with catheter-directed thrombolysis alone.

Transplantation of VEGFl65-overexpressing vascular endothelial progenitor cells relieves endothelial injury after deep vein thrombectomy.

AIM The purpose of this study was to explore the therapeutic efficacy of VEGF165-overexpressing vascular endothelial progenitor cells (EPCs) in post-thrombotic syndrome. MATERIALS AND METHODS A thrombus model was developed to mimic the in-vivo setting, and adenovirus transfection was used to overexpress VEGF165 in EPCs. These cells were transplanted into the animal model, and their ability to relieve endothelial injury was evaluated using haematoxylin and eosin staining, immunohistochemistry and scanning electron microscopy. RESULTS Ferric chloride was used to build rat models of the inferior vena cava thrombosis, and HEK 293A cells were used to amplify adenovirus that overexpresses VEGF165. EPCs were infected with adenovirus, and this was confirmed by fluorescence microscopy. Transplantation of VEGH165-overexpressing EPCs into injured endothelial sites led to faster repair of the post-thrombotic tunica intima than wild-type EPCs. CONCLUSION Transplantation of VEGF165-overexpressing EPCs was found to promote repair of the tunica intima, thus improving rehabilitation after surgery.

Safety and Efficacy of Low Dosage of Urokinase for Catheter-directed Thrombolysis of Deep Venous Thrombosis.

Background: Catheter-directed thrombolysis (CDT) has been a mainstay in treating deep venous thrombosis (DVT). However, the optimal dosage of a thrombolytic agent is still controversial. The goal of this study was to evaluate the safety and efficacy of low dosage urokinase with CDT for DVT. Methods: A retrospective analysis was performed using data from a total of 427 patients with DVT treated with CDT in our single center between July 2009 and December 2012. Early efficacy of thrombolysis was assessed with a thrombus score based on daily venography. The therapeutic safety was evaluated by adverse events. A venography or duplex ultrasound was performed to assess the outcome at 6 months, 1 year and 2 years postoperatively. Results: The mean total dose of 3.34 (standard deviation [SD] 1.38) million units of urokinase was administered during a mean of 5.18 (SD 2.28) days. Prior to discharge, Grade III (complete lysis) was achieved in 154 (36%) patients; Grade II (50–99% lysis) in 222 (52%); and Grade I (50% lysis) in 51 (12%). The major complications included one intracranial hemorrhage, one hematochezia, five gross hematuria, and one pulmonary embolism. Moreover, no death occurred in the study. Conclusions: Treatment of low-dose catheter-directed thrombosis is an efficacious and safe therapeutic approach in patients with DVT offering good long-term outcomes and minimal complications.

Bidirectional Pull-Back Technique for Retrieval of Strut-Embedded Cylinder-Shaped Filters in Inferior Vena Cava

Background IVC filters have been widely accepted as an effective method to prevent pulmonary embolism (PE) in patients with deep venous thrombosis (DVT). However, the placement of IVC filters is associated with significant complications and filter retrieval can be challenging when the filter struts are embedded into the caval wall. Material/Methods Over 26 months, we reviewed the safety and efficacy of the bidirectional pull-back technique for removing strut-embedded IVC filters in 15 consecutive patients. Retrieval procedural data such as in-dwell time, retrieval time, and fluoroscopy time were recorded. Clinical outcomes and procedure-related complications were evaluated by venography or enhanced computed tomography. Histologic tissue was analyzed to reveal the pathologic effects of chronic filter implantation. All patients underwent routine clinical follow-up at a mean time of 12 months (range, 8–14 months). Results Technical success of filter retrieval was achieved in 100%, with mean implantation of 46.6 days (range, 27–66 days). Filter types were as follows: OptEase (n=11) and Aegisy (n=4). The mean retrieval time and fluoroscopy time were 21.43±5.42 min and 7.63±2.67 min, respectively. Immediate postprocedure venography showed no procedure-related complications. Thirteen patients discontinued previously prescribed lifelong anticoagulation. There were no long-term complications during follow-up. Conclusions The bidirectional pull-back technique is safe and efficient for filter retrieval. This complex technique can be particularly useful in selected patients to remove strut-embedded cylindrical-shaped IVC filters previously considered irretrievable.