Surface Coating of Polytetrafluoroethylene with Extracellular Matrix and Anti-CD34 Antibodies Facilitates Endothelialization and Inhibits Platelet Adhesion Under Sheer Stress

Expanded polytetrafluoroethylene (ePTFE) polymers do not support endothelialization because of nonconductive characteristics towards cellular attachment. Inner surface modification of the grafts can improve endothelialization and increase the long-term patency rate of the ePTFE vascular grafts. Here we reported a method of inner-surface modification of ePTFE vascular graft with extracellular matrix (ECM) and CD34 monoclonal antibodies (CD34 mAb) to stimulate the adhesion and proliferation of circulating endothelial progenitor cells on ePTFE graft to enhance graft endothelialization. The inner surface of ECM-coated ePTFE grafts were linked with CD34 mAb in the presence of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide (EDC/NHS) solution and the physicochemical properties, surface morphology, biocompatibility, and hemocompatibility of the grafts were studied. The hydrophilicity of CD34 mAb-coated graft inner surface was significantly improved. Fourier transform infrared spectroscopy analysis confirmed ECM and CD34 mAb cross-linking in the ePTFE vascular grafts with our method. Scanning electron microscopy analysis showed protein layer covering uniformly on the inner surface of the modified grafts. The cell-counting kit-8 (CCK-8) assay confirmed that the modified graft has no obvious cytotoxicity. The modified graft showed a low hemolytic rate (0.9%) in the direct contact hemolysis test, suggesting the modification improved hemocompatibility of biopolymers. The modification also decreased adhesion of platelets, while significantly increased the adhesion of endothelial cells on the grafts. We conclude that our method enables ePTFE polymers modification with ECM and CD34 mAb, facilitates endothelialization, and inhibits platelet adhesion on the grafts, thus may increase the long-term patency rate of the prosthetic bypass grafts.

Clinical study of mechanical thrombectomy in treating in-stent restenosis of lower extremity arteriosclerosis obliterans / 中华放射学杂志

Objective To evaluate the safety and efficacy of mechanical thrombectomy in treating in-stent restenosis of lower extremity arteriosclerosis obliterans. Methods From May 2015 to Sep 2016, the clinical data of 9 cases of lower extremity arteriosclerosis obliterans who were with in-stent restenosis(3 were stent graft)were retrospectively collected, and of which 7 were males and 2 were females with a mean age of (75.4 ± 6.3)years old. All the cases were treated by mechanical thrombectomy of Rotarex catheter. All the patients were diagnosed via low-extremity artery CTA, and treated by means of the Rotarex catheter, combined with angioplasty and stent if necessary. All patients received antiplatelet therapy. Doppler ultrasonography was taken during the followed-up. Results All the 9 cases were successed in technology, without complications in hospital. All patients received Rotarex mechanical thrombectomy. Six of which used balloon and 1 stent implanted. The ABI increased from 0.29 ± 0.07 to 0.88 ± 0.07 after treatment, the difference was statistically significant(t=28.875,P<0.05). All the patients were followed up for 3—18 (median time, 11.5)months. No death and symptoms recurrence appeared during the follow-up. Conclusions Mechanical thrombectomy using Rotarex catheter is a safe and effective treatment for in-stent restenosis in lower extremity arterial diseases.

Clinical research on the application of VIABAHN stent in the treatment of branching area lesions in lower extremity arterial diseases / 中华放射学杂志

Objective To explore the security and the short term efficacy of VIABAHN stents in the treatment of branching area lesions in lower extremity arterial diseases. Methods The data of 16 patients (11 male and 5 female, aged 59.0 to 81.0 with median of 71.6) with lower extremity arterial occlusive disease from November 2014 to June 2015 were analyzed retrospectively. All lesions were located around the branching area of the lower extremity artery (3 cases in the internal iliac artery orifice, 6 cases in the deep femoral artery orifice and 7 cases in the vascular net around the knee). The short?term effects on these patients in the follow-up period, such as the success rate of surgical technique, the improvement of symptoms and the incidence of complications were summarized. Results Revascularization was technically successful in all 16 patients, and ischemic symptoms relieved significantly after the operation. The ABI were 0.36±0.12 before and 0.89±0.10 after the operation. The patients were followed up for 3 to 9 months (median 5.5 months). All the patients were achieved limb salvage and no complication occurred. Conclusions VIABAHN stent is safe and effective for the treatment of lower extremity arterial occlusive disease. The branches around the lesion can be covered with VIABAHN stents.