Synchronous culture of rabbit bone narrow-derived endothelial progenitor cells and smooth muscle progenitor cells / 第二军医大学学报

Objective: To induce synchronous differentiation of rabbit bone marrow-derived mononuclear cells into endothelial progenitor cells (EPCs) and smooth muscle progenitor cells (SPCs), and to study their biological properties and the possibility of them as seed cells for tissue-engineered venous valves. Methods: Gradient density centrifugation was used to obtain bone marrow blood mononuclear cells, which were separately cultured with EGM-2 complete medium containing 5% FBS for differentiation of EPCs and with EBM-2 medium without vascular endothelial growth factor (VEGF) containing 5% FBS and 20 ng/mL platelet-derived growth factor-BB (PDGF-BB) for differentiation of SPCs. The differentiation of EPCs and SPCs was identified by various methods. Results: EPCs were cultured for 10 days and the cells fused into monolayer, showing a "stepping stone" appearance and expressing VEGF receptor-2 (VEGFR-2), von Willebrand factor (vWF) and CD133, but not α-smooth muscle actin (α-SMA); Weibel-Palade bodies were seen within the EPCs cytoplasm under the transmission electron microscope. Biological function tests showed visible EPCs growing on the matrigel in a blood vessel-like form. SPCs were cultured for 14 days and showed the specific features of the vascular smooth muscle growth, namely, the "peak-valley" growth way. SPCs expressed CD34 and α-SMA but not vWF and VEGFR-2. Myofilaments, paralleling with the cell longitudinal axis, were seen under the transmission electron microscope. SPCs could not form vessel-like structures on the matrigel. Conclusion: Mononuclear cells can be obtained through gradient density centrifugation of the bone marrow blood, which can be synchronously induced into EPCs and SPCs, providing economical and easy seed cels for tissue-engineered venous valves.

Applied Anatomy of the Femoral Veins in Macaca fascicularis / Anatomía Aplicada de las Venas Femorales en Macaca fascicularis

The aim was to understand the anatomical features of the venous valve in Macaca fascicularis and to compare it with that of humans. The bilateral lower limbs (24 limbs from 12 animals) of Macaca fascicularis cadavers were dissected, and the femoral veins (FVs) were equally divided into distal, intermediate, and proximal sections. The external diameter of the FV in each section was measured. The venous valves were observed microscopically and stained with hematoxylin and eosin as well as trichrome. Data describing the human venous valve were collected from the current literature. No great saphenous veins were found among the 24 lower limbs from the Macaca fascicularis cadavers. The external diameters of the FVs in the distal, intermediate, and proximal sections were 3.53 ± 0.37 mm, 3.42 ± 0.55 mm, and 3.37 ± 0.54 mm, respectively. In most cases, there was one venous bivalve located in the FV approximately 0-2.71 mm below the junction of the FV and the deep femoral vein. Endothelium covered the luminal and sinusal surfaces of the leaflets. Abundant collagen fibers were found under the endothelial cells beneath the luminal surface of the leaflets. An elastin fiber network was located under the sinus endothelial surface. Smooth muscle cells in the FV extend to the edge of the valve. The venous valve of Macaca fascicularis is similar to that of humans, both morphologically and histologically. However, there is only one venous bivalve and no great saphenous vein in Macaca fascicularis.

El objetivo fue comprender las características anatómicas de la válvula venosa en Macaca fascicularis y compararla con la de los humanos. Fueron disecados bilateralmente los miembros pélvicos (24 miembros de 12 animales) de cadáveres de Macaca fascicularis; las venas femorales (VF) fueron divididas en secciones distal, media y proximal. Se midió el diámetro externo de las VFs en cada sección. Las válvulas venosas se observaron microscópicamente y se tiñeron con H-E y tricrómico. Los datos para describir la válvula venosa humana se obtuvieron desde la literatura. No se encontraron venas safenas magnas entre los 24 miembros inferiores. Los diámetros externos de las VFs en las secciones distal, media y proximal fueron 3,53±0,37 mm, 3,42 mm±0,55, y 3,37±0,54 mm, respectivamente. En la mayoría de los casos, hubo vena bivalva situada aproximadamente 0-2,71 mm debajo de la unión de la VF y la vena femoral profunda. El endotelio cubrió las superficies luminal y sinusal. Se observaron abundantes fibras de colágeno en las células endoteliales bajo la superficie luminal de las válvulas. Una red de fibras de elastina se encontró bajo la superficie del seno endotelial. Las células musculares lisas en las VFs se extiendían hasta el margen de la válvula. La válvula venosa del Macaca fascicularis es similar a la de los seres humanos, morfológica e histológicamente. Sin embargo, sólo hubo una vena bivalvular, y no se observaron venas safenas en Macaca fascicularis.

Current research and development of tissue engineered venous valve / 中国组织工程研究

OBJECTIVE: To review the current research of tissue engineered venous valve at home and abroad, to analyze the developing trend of tissue engineered venous valve in the clinical application.METHODS: A computer retrieve was performed among PubMed, ProQuest Health & Medical Complete database, Springer English Academic Journal Full-text database, Elsevier Full-text database between January 2000 and August 2009, with the key words of "tissue engineering venous valve", and the language was limited to English. At the same time, Chongqing VIP database, Qinghua Academic Journals Database, Chinese Biomedical Literature database were also screened on computer by using the

Percutaneous placed bioprosthetic venous valve in the treatment of deep vein reflux:animal experiments and clinical trials / 中华放射学杂志

ObjectiveTo evaluate the efficiency of percutaneously placed bioprosthetic bicuspid venous valve(BVV)in the treatment of deep vein insufficiency in animal experiments and clinical trials.MethodsBVV was made of two pieces of lyophilized porcine small intestinal submucosa(SIS)which were attached to a stent frame.Three kinds of BVVs(BVV1,BVV2,BVV3)was developed using different kinds of stent frames and different Methodsof attachment. BVV1,BVV2 and BVV3 were percutaneouslv placed into ovlne's jugular veins acrossed the nature valves.Ascending and descending angiography were performed before and after BVVs placement.The patency of veins and the function of valves was evaluated during 5 weeks to 6 months follow-up. In clinical trial,BVV1 and BVV3 were percutaneouslv placed into 3 and 15 patients with chronic venous insufficiency(CVI)respectively.The patency of veins and the function of valves was also evaluated during 1 to 3 years' follow-up.ResultsIn animal experiment,BVV1,BVV2,and BVV3 were placed to 24,26 and 12 ovine's jugular veins respectively.During 5 weeks to 6 months followup period,22(88.0%),24(92.3%)and 12 of the BVVs exhibited good function.Endothelium of both surfaces of SIS leaflets was complete in approximately 3 months. SIS was graduallv reabsorbed and replaced by the host's own cells.Three BVV1 were placed into 3 patients with CVI.At the third year's follow-up,symptoms relieved in 2 cases and no change of clinical symptoms was found in 1 patient.BVV3 were percutaneously placed into 15 patients with advanced symptomatic CVI.At one month and 3 months' followup after BVV3 placement,all BVV3 functioned well. However,BVV3 were flexible and functioned well in only 4 cases at 1 year's follow-up.Intravascular ultrasound revealed thickened rigid cusps with valve leakage of difierent Jevcls and no symptom resolved in 11 cases. ConclusionsPercutaneous implantation of bioprosthetic BVV is a promising method in the treatment of CVI.Intimal hyperplasia is an important factor which damages long-term durability and flexibility.

Intermediate Stage Report about Change of Deep Venous Valve Function after Superficial Vein Surgery of Lower Extremity / 中国普外基础与临床杂志

Objective To evaluate improved effect for deep venous valve function after superficial vein surgery of lower extremity in the intermediate stage.Methods Totally 43 patients (55 limbs) with varicose veins of lower extremity were enrolled to accept surgical management of vein systems in our department from March 2006 to October 2006.All patients were respectively followed up after 6 months and 4 years about the changes of deep venous valve function with color Doppler ultrasonography.Results Thirty-nine patients’ deep venous valve function kept well up to now,and there was no significant difference between the two results.Four patients without proximal saphenous vein ligation recurred,and there was reflux in deep venous.Conclusion Endovenous laser treatment and ablation of varicose veins of lower extremity with deep venous insufficiency could improve deep venous valve function effectively.Proximal great saphenous vein ligation is important for successful operation.

Venous External Valvuloplasty in the Treatment of Moderate or Severe Primary Incompetent Deep Venous Valve of Lower Limbs / 中国医师杂志

Objective To evaluate the effectiveness of venous external valvuloplasty in treatmeant of moderate or severe incompetent deep venous valve.Methods 54 patients with moderate and severe primary incompetent deep venous valve underwent anterograde and retrograde venous angiography of lower limbs, the angiography showed that reflux degree were 2～4grade. 54 patients were divided into two groups.The first group patients(n=32) without serious injured free margin of venous valve leaves were treated by venous external valvuloplasty,the other group patients with serious injured free margin of valve leaves(n=22),were other treatment.Results The showed excellent curative effect,were obtained better effect 29(90.6%) of the 32 cases were 3(9.4%) of 32 cases.The symptoms of all patients were disappearance and ulcer were close up. The colour Doppler ultrasonography had shown that blood was not flow backwards in the vein.Conclusions The authors believe that the good results may be expected in the opration of venous external valvuloplasty in patients with moderate and severe primary incompetent deep venous valve whose free margin of valve leaves were not serious injured .

AN EXPERIMENTAL STUDY ON THE EVOLUTION OF VENOUS VALVES IN ARTERIALISED VENOUS FLAP / 解放军医学杂志

Skin flaps from rabbit thighs were raised. The saphenous veins of the flaps were anastomosed with the femoral arteries.The valves in the veins were studied histologically. Fibrous tissue of the venous valve at the site of its junction with the venous wall underwent "fatigue" injury resulting in fracture of the valve.Theraby the valve opened according to the direction of blood flow, and the valvular tissue began to adhere to the venous wall.The results suggested that rapid blood flow with high pressure might remodel the venous valve in an arterialized venous skin flap.

THE RELATIONSHIP BETWEEN STRUCTURE AND MECHANICS OF THE VENOUS VALVE / 解剖学报

The human venous valve of the brachial,femoral and long saphenous veins wereexamined with light,transmission and scanning electron microscopy.The observationshows that the venous valve is composed of three functional layers covered withendothelium on both surfaces.A loosely structured layer is located underlying theendothelium.A network mainly containing randomly oriented elastic fibers was foundnear the side towards the lumen.To the side towards the venous wall,there is adense layer composed of eircumferentially and transversly oriented collagen bundles.Some smooth muscle cells extend from the wall of the vein to the base of thevenous valve.The elastic fibers and smooth muscle cells together with the collagenfibers contribute to the mechanical load-bearing performance of the valve and to thepassive closing and openning mechanism.In addition,the smooth muscle cells mightplay an active role in the normal functioning of the valve.The scanning and transmission electron microscopy of venous valve showdifferent arrangement of the endothelium.On the surface of the valve next to the wallof the vein,the endothelial cells are transversely arranged,while on the othersurface over which the current of blood flows,the cells are longitudinally arrangedin the direction of the current.These accord with the role of fluid mechanics.12 normal venous valves were tested by universal testing instrument (Instrontype 1122).The mean value of the maximum tension of the valve is 1 N.Theaverage value of the tensile ultimate strength is 10N/mm~2.