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.

Biocompatibility of porcine small intestinal submucosa and rat endothelial progenitor cells in vitro.

OBJECTIVE: This study investigated the biocompatibility of the small intestinal submucosa (SIS) and endothelial progenitor cells (EPCs) by co-cultivating EPCs and SIS in vitro and observing EPC growth on the SIS. METHODS: The porcine SIS was prepared and bone marrow mononuclear cells (BMMNCs) were isolated from 3 or 4-week old male SD rats. Cellular morphology was observed by light microscopy and scanning electron microscopy (SEM) and viabilities by the MTT assays. Endothelial progenitor cells (EPCs) were phenotyped by immunocytochemistry, immunofluorescence microscopy and flow cytometry. Vascular lumen formation was evaluated by the Matrigel tube formation assays. EPCs were seeded onto the SIS and production of angiogenin-1 and endothelial cell growth factor (VEGF) by EPCs was examined by ELISA and immunoblotting assays. RESULTS: Light microscopy and SEM showed that the mechanically and chemically treated small intestinal submucosa was composed of cell-free extracellular matrix. Immunohistochemistry, and flow cytometry revealed that the EPCs expressed appropriate surface markers including CD34, CD133, and VEGFR-2. Furthermore, the EPCs formed lumen-like structures and the SIS significantly enhanced the growth of EPCs in vitro. CONCLUSION: SIS has good biocompatibility with EPCs. SIS pre-seeded with EPCs can be potentially applied as an alternative scaffold material in artificial blood vessel prosthesis.

Immediate and middle term outcome of symptomatic spontaneous isolated dissection of the superior mesenteric artery.

PURPOSE: Spontaneous isolated dissection of the superior mesenteric artery (SIDSMA) is a rare but fatal condition. Herein, we report the therapeutic outcome of a contemporary series of 12 patients with SIDSMA who were treated with conservative, anticoagulation, or endovascular therapy. METHODS: Revascularization was measured according to recanalization of the primary arterial occlusive lesion and reperfusion was measured by flow through the occluded vessel. Pain was evaluated by using the visual analog scale (VAS) at admission and at each follow-up visit. RESULTS: Type I SIDSMA was seen in 3 (25%) patients, type IIa in 4 (33.3%) patients, and type IIb in 5 (41.7%) patients. No patient had type III SIDSMA. The false lumens were patent in 6 (50%) patients. Partial thrombosis in the false lumen was demonstrated in CT scans in 5 (41.7%) patients and total thrombosis in 1 (8.3%) patient. Four (33.3%) patients received conservative therapy, and 2 (16.7%) patients received anticoagulation therapy. All six patients resumed normal blood flow in the SMA. The remaining six patients received endovascular stenting. After stent placement, excellent distal blood flow was restored. Abdominal pain was completely resolved in all patients except in one patient. No complications associated with SMA dissection occurred. CONCLUSION: If bowel perfusion is not compromised and the SMA aneurysm is not likely to rupture in patients with a symptomatic SIDSMA, conservative, or anticoagulation therapy can be considered. If patient has sustained intestinal ischemic symptoms, and severe compression of the true lumen, or dissecting aneurysm likely to rupture, endovascular therapy, or surgery should be adopted.

Stenting of iliac vein obstruction following catheter-directed thrombolysis in lower extremity deep vein thrombosis.

BACKGROUND: Catheter-directed thrombolysis (CDT) for deep venous thrombosis (DVT) of the lower extremity has good effect, but whether iliac vein stent placement after thrombolytic therapy is still controversial. The goal of this study was to evaluate the efficacy of stent placement in the iliac vein following CDT in lower extremity DVT. METHODS: This was a single-center, prospective, randomized controlled clinical trial. After receiving CDT, the major branch of the distal iliac vein was completely patent in 155 patients with lower extremity DVT, and 74 of these patients with iliac vein residual stenosis of >50% were randomly divided into a control group (n = 29) and a test group (n = 45). In the test group, stents were implanted in the iliac vein, whereas no stents were implanted in the control group. We evaluated the clinical indicators, including patency of the deep vein, C in CEAP classification, Venous Clinical Severity Score (VCSS), and Chronic Venous Insufficiency Questionnaire (CIVIQ) Score. RESULTS: All patients had postoperative follow-up visits for a period of 6-24 months. Venography or color ultrasound was conducted in subjects. There was a significant difference between the patency rate at the last follow-up visit (87.5% vs. 29.6%) and the 1-year patency rate (86.0% vs. 54.8%) between the test and control groups. The change in the C in CEAP classification pre- and post-procedure was significantly different between the test and control groups (1.61 ± 0.21 vs. 0.69 ± 0.23). In addition, at the last follow-up visit, VCSS and CIVIQ Score were both significantly different between the test and control groups (7.57 ± 0.27 vs. 0.69 ± 0.23; 22.67 ± 3.01 vs. 39.34 ± 6.66, respectively). CONCLUSION: The stenting of iliac vein obstruction following CDT in lower extremity DVT may increase the patency of the deep vein, and thus provides better efficacy and quality of life.

[Endovascular therapy of superior mesenteric artery embolism].

OBJECTIVE: To explore the safety and immediate efficacy of endovascular treatment for superior mesenteric artery embolism. METHODS: From November 2007 to October 2012, 18 cases of superior mesenteric artery embolism were treated by thrombus extraction and/or catheter-directed thrombolysis. There were 13 males and 5 females with an age range of 44-91 years. The concurrent conditions included atrial fibrillation (n = 8) and rheumatic valve disease (n = 3). All diagnoses were made with abdominal enhanced computed tomography (CT) examination. Embolism was predominantly located at 3 to 10 cm away from opening. The procedures included thrombus extraction plus system thrombosis (n = 3), thrombus extraction and catheter-directed thrombolysis (n = 6), catheter-directed thrombolysis (n = 5) and thrombus extraction, catheter-directed thrombolysis and PTA (n = 2). RESULTS: The technical success rate was 100%. Two cases had new embolism in popliteal artery. Another case with peritoneal irritation syndrome died after automatic discharge. The other 17 patients obtained satisfactory results and were followed up after 6 months by color Doppler ultrasound or abdominal enhanced CT. It showed that superior mesenteric arteries were unobstructed, but local stenosis occurred in 2 cases. CONCLUSION: Endovascular interventional therapy is both safe and efficacious in the treatment of superior mesenteric artery embolization. And its immediate effect is satisfactory.

Rapamycin and 3-methyladenine regulate apoptosis and autophagy in bone-derived endothelial progenitor cells.

BACKGROUND: Mammalian target of rapamycin (mTOR) is involved in a caspase independent form of programmed cell death called autophagy. The aim of this research was to investigate the effects of rapamycin and 3-methyladenine (3-MA) on autophagy, proliferation, apoptosis, and cell-cycle parameters of rat bone marrow-derived endothelial progenitor cells (EPCs). METHODS: Mononuclear cells isolated from rat bone marrow were treated with rapamycin (0.01, 0.1, 1, or 10 µg/L) or 3-MA (1.25, 2.5, 5, or 10 mmol/L) for 24 hours. Expression of the autophagy marker protein LC3-II was analyzed by Western blotting. Apoptosis and cell-cycle progression were analyzed by flow cytometry. Cell proliferation was measured using the MTT assay. RESULTS: Rapamycin treatment of EPCs induced apoptosis and autophagy and inhibited proliferation and cell-cycle progression in a dose-dependent manner. Treatment with 5 mmol/L 3-MA promoted cell proliferation; in contrast, treatment with 10 mmol/L 3-MA promoted apoptosis and induced S-phase arrest. CONCLUSIONS: Rapamycin treatment of EPCs induced apoptosis and autophagy. Low concentrations of 3-MA had no significant effect on the proliferation and apoptosis of EPCs; The 5 mmol/L group promoted cell proliferation, but had no effect on the apoptosis; the 10 mmol/L group inhibited the proliferation and promoted apoptosis through the cell cycle.

Endovascular treatment of iliac vein compression syndrome.

BACKGROUND: Iliac vein compression syndrome (IVCS), the symptomatic compression of the left common iliac vein between the right common iliac artery and the vertebrae, is not an uncommon condition. The aim of this research was to retrospectively evaluate long-term outcome and the significance of endovascular treatment in patients with left IVCS. METHODS: Between January 1997 and September 2008, 296 patients received interventional therapy in the left common iliac vein. In the second stage, 170 cases underwent saphenous vein high ligation and stripping. Two hundred and thirty-one cases were followed up over a period of 6 to 120 months (average 46 months) and evaluated for symptom improvement with color ultrasound and ascending venography. RESULTS: The stenotic or occlusive segments of the left iliac vein were successfully dilated in 285 cases, of whom 272 received stent implantation therapy. Most of the patients achieved satisfactory results on discharge. During the follow-up period, varicose veins were alleviated in 98.7% of the patients, and leg swelling disappeared or was obviously relieved in 84% of cases. About 85% of leg ulcers completely healed. The total patency rate was 91.7% as evaluated with color ultrasound and 91.5% with ascending venography. CONCLUSIONS: Endovascular treatment of IVCS provides effective symptomatic improvement and good long-term patency in most patients.

Transplantation of VEGF165-gene-transfected endothelial progenitor cells in the treatment of chronic venous thrombosis in rats.

BACKGROUND: The organization and recanalization of thrombi is a dynamic and complex process. The aim of this research was to study the cotherapeutic effect of stem cell transplantation and gene transfection on chronic venous thrombosis. METHODS: We constructed a recombinant adenoviral vector carrying the vascular endothelial growth factor 165 (VEGF165) gene by using the pAdEasy system, which was subsequently identified and amplified. Simultaneously, endothelial progenitor cells (EPCs) were isolated from rat bone marrow using Ficoll, cultured in EBM-2MV medium, and identified. Then, the cells were transfected with the recombinant Ad-VEGF165. The EPCs were labeled with 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine (Dil) before transplantation. A rat model of chronic vein thrombosis was developed by partial ligation of the inferior vena cava. The rats were randomly divided into 4 groups (n = 25, each): A, Ad-VEGF165/EPC-transplantation group received 1 ml (10(6)) of Ad-VEGF165/EPCs; B, EPC-transplantation group received 1 ml (10(6)) of EPCs; C, Ad/EPC-transplantation group received 1 ml (10(6)) of Ad/EPCs; D, control group received 1 ml of the transplantation medium. The thrombi and adjacent caval walls were harvested 28 days after transplantation; real-time quantitative polymerase chain reaction was used to detect the expression level of vascular endothelial growth factor (VEGF) mRNA; and western blotting was used to measure changes in VEGF protein expression. Hematoxylin-eosin staining and immunohistochemical staining were performed to detect recanalization. Neovascularization was detected by immunohistochemical staining using the antibody for von Willebrand factor (vWF), which is a component of endothelial cells. The capillary density was quantitatively determined by counting the capillaries under a high-power microscope. RESULTS: The Ad-VEGF165 was constructed, and bone-marrow-derived EPCs were cultivated and successfully identified. We determined the optimum transfection ratio that promoted the growth of EPCs. After transfection, the EPCs secreted the VEGF protein. After transplantation, the in vivo survival of EPCs and their differentiation into endothelial cells were determined by detecting the fluorescence associated with the Dil stain. VEGF mRNA was expressed in groups A, B, C and D after transplantation, and the VEGF mRNA level in group A was significantly higher than those in groups B, C and D (P < 0.05); the VEGF mRNA levels in groups B and C were significantly higher than those in group D (P < 0.05), and there was no statistical significance between the VEGF mRNA levels in groups B and C. The recanalization capillary density in group A was significantly higher than those in groups B, C (P < 0.05) and D (P < 0.01); the recanalization capillary densities in groups B and C were significantly higher than that in group D (P < 0.05). Moreover, there was no statistical significant difference between the values for groups B and C. CONCLUSIONS: The EPCs were successfully transfected by Ad-VEGF165. A suitable transfection ratio can improve the efficiency of EPCs and the possibility of promotion of angiogenesis after transplantation. Transfected EPCs caused accelerated organization and recanalization of vein thrombi.

[Curative effects of extrusive and Fogarty balloon catheter embolectomy in acute femoral vein thrombosis: experiment with rabbits].

OBJECTIVE: To compare the influence extrusive and Fogarty balloon catheter embolectomy on the patency rate of bloodstream and the damage of the wall of vein in acute femoral vein thrombosis. METHODS: Eighty rabbits were randomly divided into 4 groups: Group A (n = 25) undergoing ligation of unilateral femoral to establish acute femoral vein thrombosis model and treated by extrusion of the hind leg muscles 24 h after the operation, Group B (n = 25) treated by Fogarty balloon catheter embolectomy 24 h after establishment of the thrombosis model, Group C (n = 25) undergoing sham operation, and Group D (n = 5) as normal controls.7, 14, and 28 days after the treatment digital subtraction angiography (DSA) was conducted to observe the patency rate of the vessel.1, 4, 7, 14, and 28 days after the treatment specimens of the thrombotic and corresponding sections of the veins were collected from the 4 groups (on days 1 and 7 for Group D) to undergo transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Quantitative reverse transcription and polymerase chain reaction was used to detect the level of tissue thromboplastin (TF). ELISA was used to detect the levels of thromboxane B(2), (TXB(2)) and 6-keto-prostaglandin F1alpha (PGF1alpha). RESULTS: Occlusion was seen in 3 femoral veins of Group B and one femoral vein of Group (P < 0.01), and the other veins were all patent. TEM and SEM showed that the endothelial cell injury was slight in Group A, and aggravated in Group B. TF mRNA expression could be seen 1 day after the treatment in Groups A, B, and C, and peaked on the day 7, and not found in Group D at any time points (all P < 0.01); and the TF mRNA levels at different time points of Group A were all significantly lower than those of Group B (all P < 0.01). The TXB(2) expression levels on days 1 and 7 of Groups A, B, and C were all significantly higher than those of Group D; especially those of Group B (all P < 0.01). The 6-keto-PGF(1)alpha levels on days 1 and 7 of Group D were both significantly higher than those of Groups A, B, and C (all P < 0.01). CONCLUSION: Compared with Fogarty balloon catheter embolectomy, extrusion embolectomy can discard the thrombus more thoroughly and guarantee the patency rate of bloodstream. Both extrusion embolectomy and Fogarty balloon catheter embolectomy, especially the latter, cause damage to the blood vessel endothelium.

Radical correction of Budd-Chiari syndrome.

BACKGROUND: Interventional therapy is widely accepted as the first choice for the treatment of the Budd-Chiari syndrome, but the use of radical correctional therapy should not be discarded. This study describes radical correction by controlling bleeding from distal end of pathological segment of the inferior vena cava (IVC) and discusses potential surgical errors and postoperative complications. METHODS: Of the 216 patients in the study, 78 were treated with simple membranectomy, 64 with dissection of the pathological segment of the IVC and vascular prosthesis or pericardial patch plasty, 60 with resection of the pathological segment of the IVC and orthotopic graft transplantation with vascular prosthesis, and 14 with resection of the occlusive main hepatic vein and its upper IVC, hepatic venous outflow plasty and vascular prosthesis orthotopic graft transplantation from the hepatic venous entrance to the IVC of right atrial ostium. RESULTS: Except 14 cases who were discharged after hepatic vein outflow plasty, four cases died postoperatively, and 198 patients were discharged without complications. The symptoms of 15 patients were relieved partially and 2 without any change. There were no deaths intraoperatively. Of the 112 cases who were followed up for 72 months, 13 suffered from a relapse. CONCLUSIONS: Radical correction is a beneficial therapy in the treatment of Budd-Chiari syndrome.

Effects of bone marrow-derived endothelial progenitor cell transplantation on vein microenvironment in a rat model of chronic thrombosis.

BACKGROUND: Endothelial progenitor cells (EPCs) have been used in both experimental studies and clinical treatments of limb ischemia, as well as in the construction of engineered vascular tissue. The objective of this study was to investigate the effects of transplanted bone marrow-derived EPCs on the vein microenvironment in a rat model of chronic vein thrombosis. METHODS: Mononuclear cells were isolated from the bone marrow of immature rats by density gradient centrifugation, cultured, and then transplanted into experimentally induced thrombi into inferior vena cava through the femoral vein. Vascular endothelial growth factor (VEGF), angiopoietin-1 (ANG-1) and monocyte chemotactic protein-1 (MCP-1) mRNA and protein expression levels were measured by real-time quantitative polymerase chain reaction and Western blotting of thrombi and adjacent caval walls 28 days post-transplantation. RESULTS: Levels of VEGF, ANG-1, and MCP-1 mRNA in EPC-transplanted thrombi were 100%, 230.7%, and 212.5% of levels detected in the sham-operated group (P < 0.01), and 99.9%, 215.4%, and 177.8% of levels detected in the experimental control group (P < 0.01). VEGF, ANG-1 and MCP-1 protein levels exhibited a similar trend. CONCLUSIONS: Transplanted bone marrow-derived EPCs appear to alter the vein microenvironment in experimentally induced chronic vein thrombosis by upregulating cytokines associated with thrombic organization and recanalization.