Cuff Technique for Small-Diameter Vascular Grafts in the Systemic Arterial Circulation of the Rat

This study determined the feasibility of the cuff technique for small-caliber vascular grafts in a rat model. A graft was implanted with the cuff technique or suture technique in a 1-cm segment of the abdominal aorta in 12 rats. The mean aortic clamp time was 29 minutes with the cuff technique and 44 minutes with the suture technique; the cuff technique was significantly shorter. Abdominal angiography at 1 week after implantation showed no significant stenosis in 9 rats, focal stenosis of the mid-portion of the graft in 1 rat with each technique, and total occlusion of the graft in 1 rat with the suture technique. We have successfully used the cuff technique for anastomosis for small-caliber vascular grafts in an animal model.

Application value of artery approach in the lower colon region combined with portal vein resection and allograft vascular grafts in radical pancreaticoduodenectomy / 中华消化外科杂志

Objective To investigate the application value of artery approach in the lower colon region combined with portal vein (PV) resection and allograft vascular grafts in radical pancreaticoduodenectomy for pancreatic cancer combined with vascular invasion.Methods The retrospective descriptive study was conducted.The clinicopathological data of 13 patients with pancreatic cancer involving in PV,splenic vein or junction who were admitted to the Beijing Chao Yang Hospital of Capital Medical University from March 2014 to June 2015 were collected.The superior mesenteric artery (SMA),tumors and soft tissues (including involved vessels) in the right of the celiac trunk were resected after exploring SMA and evaluating resectability of tumors.Patients underwent PV-splenic vein resection and reconstruction with allogenic vein.Observation indicators:(1) surgical situations;(2) postoperative situations;(3) follow-up situation.Follow-up using outpatient examination and telephone interview was performed to detect survival of patients and tumor recurrence and metastasis up to April 2016.Measurement data with normal distribution were represented as (x)±s.Results (1) Surgical situations:13 patients successfully underwent radical pancreaticoduodenectomy via artery approach in the lower colon region combined with PV,splenic vein resection and allograft vascular grafts.Operation time and volume of intraoperative blood loss were respectively (489 ± 31) minutes and (407 ± 96) mL,without intra-and post-operative deaths.(2)Postoperative situations:of 13 patients,3 and 1 patients were respectively complicated with pancreatic fistula (2 in grade A and 1 in grade B) and gastroplegia,and cured by conservative treatment.There was no occurrence of bleeding,intraperitoneal infection,diarrhea,anastomotic stenosis and thrombus.The median duration of postoperative hospital stay was 12 days.Results of postoperative pathological examination:of 13 patients,high-,moderate-and low-differentiated adenocarcinoma was detected in 2,7 and 4 patients respectively.Three patients had negative vascular margin,2 had tunica intima invasion and 8 had tumor cell invasion in vascular adventitia.One,2,6,4 patients were detected in Ⅰ B,Ⅱ A,Ⅱ B and Ⅲ staging,respectively.The negative margin rate by postoperative pathological examination was 11/13.(3) Follow-up situation:13 patients were followed up 10 months postoperatively,with good survival and without tumor recurrence or metastasis.Conclusion The radical pancreaticoduodenectomy via artery approach in the lower colon region combined with PV/SMV resection and allograft vascular grafts is safe and feasible for pancreatic cancer involving in PV,splenic vein or junction,it can also evaluate early resectability of tumors,with good operative efficacy.

Application value of artery approach in the lower colon region combined with portal vein resection and allograft vascular grafts in radical pancreaticoduodenectomy / 中华消化外科杂志

Objective To investigate the application value of artery approach in the lower colon region combined with portal vein (PV) resection and allograft vascular grafts in radical pancreaticoduodenectomy for pancreatic cancer combined with vascular invasion.Methods The retrospective descriptive study was conducted.The clinicopathological data of 13 patients with pancreatic cancer involving in PV,splenic vein or junction who were admitted to the Beijing Chao Yang Hospital of Capital Medical University from March 2014 to June 2015 were collected.The superior mesenteric artery (SMA),tumors and soft tissues (including involved vessels) in the right of the celiac trunk were resected after exploring SMA and evaluating resectability of tumors.Patients underwent PV-splenic vein resection and reconstruction with allogenic vein.Observation indicators:(1) surgical situations;(2) postoperative situations;(3) follow-up situation.Follow-up using outpatient examination and telephone interview was performed to detect survival of patients and tumor recurrence and metastasis up to April 2016.Measurement data with normal distribution were represented as (x)±s.Results (1) Surgical situations:13 patients successfully underwent radical pancreaticoduodenectomy via artery approach in the lower colon region combined with PV,splenic vein resection and allograft vascular grafts.Operation time and volume of intraoperative blood loss were respectively (489 ± 31) minutes and (407 ± 96) mL,without intra-and post-operative deaths.(2)Postoperative situations:of 13 patients,3 and 1 patients were respectively complicated with pancreatic fistula (2 in grade A and 1 in grade B) and gastroplegia,and cured by conservative treatment.There was no occurrence of bleeding,intraperitoneal infection,diarrhea,anastomotic stenosis and thrombus.The median duration of postoperative hospital stay was 12 days.Results of postoperative pathological examination:of 13 patients,high-,moderate-and low-differentiated adenocarcinoma was detected in 2,7 and 4 patients respectively.Three patients had negative vascular margin,2 had tunica intima invasion and 8 had tumor cell invasion in vascular adventitia.One,2,6,4 patients were detected in Ⅰ B,Ⅱ A,Ⅱ B and Ⅲ staging,respectively.The negative margin rate by postoperative pathological examination was 11/13.(3) Follow-up situation:13 patients were followed up 10 months postoperatively,with good survival and without tumor recurrence or metastasis.Conclusion The radical pancreaticoduodenectomy via artery approach in the lower colon region combined with PV/SMV resection and allograft vascular grafts is safe and feasible for pancreatic cancer involving in PV,splenic vein or junction,it can also evaluate early resectability of tumors,with good operative efficacy.

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.

Construction of Completely Biological Tissue-Engineered Small-Diameter Blood Vessel Based on a Biological Hybrid Scaffold / 中国康复理论与实践

@#Objective To prepare completely biological tissue-engineered small-diameter blood vessel based on a biological hybrid scaffold.MethodsEndothelial cells and smooth muscle cells were isolated from the porcine aorta and expanded in vitro. Mixture of smooth muscle cells and porcine fibrin was prayed coating on the decellularized canine carotid artery. Then, the inner surface of the decellularized artery was seeded with the endothelial cells to construction of completely biological tissue-engineered small-diameter blood vessel. The tissue-engineered blood vessel was evaluated with Hematoxylin and Eosin (H&E) staining and scanning electron microscopy.ResultsHistology examination revealed that the completely biological tissue-engineered small-diameter had intact media and intima. Scanning electron microscopy examination confirmed that the inner surface of tissue-engineered blood vessel was covered with intact monolayer endothelial cells and the external surface was covered with multilayer smooth muscle cells.ConclusionThe completely biological tissue-engineered small-diameter with intact media and intima was prepared using mixture of blood vessel cells and porcine fibrin on the decellularized canine carotid artery.

Constructing a Completely Biological Hybrid Scaffold for Small-Diameter Vascular Tissue Engineering Using Fibrin and Decellularized Artery / 中国康复理论与实践

@#Objective To prepare a completely biological hybrid scaffold for small-diameter vascular tissue engineering using porcine fibrin and decellularized canine carotid artery.MethodsPorcine fibrin was sprayed coating on the external surface of decellularized canine carotid artery to construct completely biological hybrid scaffold for small-diameter vascular tissue engineering. The completely biological hybrid scaffold was evaluated with Hematoxylin and Eosin (H&E) staining, scanning electron microscopy and biomechanics test.ResultsHistology examination revealed that the porcine fibrin was sprayed coating uniformly on the external surface of decellularized canine carotid artery. Scanning electron microscopy examination confirmed that the external surface of completely biological hybrid scaffold was smooth and uniformly. Compared with fresh canine carotid artery and decellularized artery, the biological hybrid scaffold had similar burst and breaking strength. Furthermore, compared with decellularized artery, the biological hybrid scaffold had higher compliance.ConclusionThe porcine fibrin was sprayed coating uniformly on the external surface of decellularized canine carotid artery to prepare a completely biological hybrid scaffold for small-diameter vascular tissue engineering. The biological hybrid scaffold had appropriate biomechanical properties and had potential to serve as scaffolds for small-diameter vascular tissue engineering.

Advances in scaffold materials of vascular tissue engineering / 国际生物医学工程杂志

Vascular graft is an important component of vascular tissue engineering. In the past several decades, the scaffold materials for vascular tissue engineering have developed from simple natural materials to compound of degradable polymer and biological materials. Great progress has been made in material design and procossing. Electrospirming has been introduced to replace the manual processing. However, more work still needs to be done to make the method of design and processing more satisfactory. Main efforts should be put into the studies on improving the mechanical properties and biological functions of the scaffold materials.

Experimental Study of Vascular Tissue Engineering / 中国康复理论与实践

@#Objective To obtain the experimental data of vascular tissue engineering.MethodsThe vascular endothelial cells (VEC) and vascular smooth muscle cells (VSMCs) were acquired and cultured, and then seeded on vascular tissue engineering materials. The porous gelatin-chitosan scaffold with VSMCs was subcutaneously implanted, followed by the observation of the cell growth ten days later.ResultsThe two kinds of cells were successfully cultured and their morpholoical and immunohistochemical characteristics were consistent with vascular endothelial and VSMCs respectively. The VSMCs could grow extensively on the scaffold after the in vivo implantation. The scaffold were wrapped by the fibrous tissue ten days later after the in vitro implantation of VSMCs. The seed cells grew in the scaffold, and the vessel cavity seen in the center of the scaffold, was quite different from the normal vessel structure.ConclusionIt is feasible to implant the VSMCs with fibrin gels into the living body. The vessels reconstructed, though different from the normal structure, is similar to the embryo of the vessels.

Transfection of Nitric Oxide Synthase Gene with Adenovirus Can Inhibit the Intimal Hyperplasia of Venous Autografts / 中国康复理论与实践

@#ObjectiveTo investigate the effects of nitric oxide synthase (NOS) genetic transfection on the intimal hyperplasia of venous autografts. MethodsThe external jugular veins were autografted into abdominal aorta arteries in 20 Wistar rats, which were divided evenly into experimental or control groups. The transplanted veins of experimental group were immersed in the adenovirus-mediated eNOS gene solution for 15 minutes just before anastomosis. The transplanted vascular samples were taken out 2 weeks after operation. The intimal thickness(IH), degree of restenosis(DR), expression of PCNA and NOS mRNA were determined with histology and transcription polymerase chain reaction (PCR). ResultsThe IH, DR and PCNA decreased, while the expression of eNOS mRNA increased comparing with control group(P<0.01). ConclusionTransfection of NOS gene can inhibit the intimal hyperplasia of venous autografts.

Endovascular repair for thoracic dissecting aneurysm / 中国普通外科杂志

Objective To study the clinical effects of endovascular stent-graft repair for thoracic aortic aneurysm(TDA).Methods The clinical records of 32 patients with thoracic aorta dissecting aneurysm,including 26 men and 6 women,who underwent endovascular repair were retrospectively analyzed.The characteristics,location,and anatomic condition of dissecting aneurysm were evaluated using CTA before operation.Under general or local anesthesia,32patients underwent endovascular repair under dynamic DSA.For those patient,8 Talent,22 Yuhengjia(Beijing) and 2 Microinvasive(Shanghai) stent grafts were used.Results Among them 32 patients the distance between entry tear and left subclavian artery was

Diagnosis and treatment of Leriche syndrome: a report of 33 cases / 中国普通外科杂志

Objective To summarize the diagnosis and treatment of 33 cases of Leriche syndrome. Methods A retrospective review of the clinical data of 33 cases of Leriche syndrome was done. Results Claudication and impotence occurred in 79.9% and 70.4% of the cases. Color Doppler ultrasonography, especially combining with CTA or MRA, was helpful for the diagnosis. Aortic angiography or DSA was necessary for the determination of the clinical patterns and selecting the therapeutic methods. Surgical patterns selestion should be considering the patients' general status and conditions of the affected vessels. Surgical treatment was performed on 25 cases, including12 aortoiliac artery bypasses , 6 aortobifemoral artery bypasses , 4 axillo bifemoral artery bypasses, 2 embolectomies by Fogarty tube only and 1 aortal interposition with artificial vessel plus renal artery plasty. Aorta iliac artery bypasses get the best results with 1 year patency rate(100%) in all cases, and 5 year patency rate of 75.0%, which was significantly superior to those axillo bifemoral artery bypass grafts with 5 year patency rate of 37.5%. All the other 8 patients without operation died within 5 months. Conclusions Early diagnosis and comprehensive therapy should be adopted to improve the long term patency rates of grafts transplantation in Leriche syndrome.