SEM image analysis of endothelium of distended autogenous vein grafts

ＳＥＭｉｍａｇｅａｎａｌｙｓｉｓｏｆｅｎｄｏｔｈｅｌｉｕｍｏｆｄｉｓｔｅｎｄｅｄａｕｔｏｇｅｎｏｕｓｖｅｉｎｇｒａｆｔｓＱｉａｎＪｉｘｉａｎ（钱济先）；ＨｕａｎｇＹａｏｔｉａｎ（黄耀添）；ＢａｏＣｈｕｎｊｉｅ（包春杰）；ＷａｎｇＪｕｎ（王军）；ＬｕＹ...

Changes of Ca^2+ activated potassium channels and cellular proliferation in autogenous vein grafts

Objective: To investigate changes of Ca2+ activated potassium channels (KCa) in autogenous vein grafts. Methods: Contraction of venous ring was measured by means of perfusion in vitro. The intimal rabbits proliferation of vascular and proliferation of cultured smooth muscle cells(vascular smooth muscle cells, VSMCs)were observed by the means of computerised image analysis and MTT method respectively. Furthermore, whole cell mode of patch clamp was used to record KCa of VSMCs isolated from autogenous vein grafts. Results: One week after transplantation there were no significant differences of contraction and intimal relative thickness between autogenous vein grafts and control. Contraction and intimal relative thickness of autogenous vein graft were significantly increased 2 weeks after transplantation (P<0.05, n=8 vs control), and they was more enhanced 4 weeks after vein transplantation (P<0.01, n=8 vs control).TEA(blocker of Ca2+ activated potassium channels)increased MTT A490 nm value of VSMCs from femoral vein in a dose dependent manner(P<0.05, n=8). KCa current density was significantly attenuated in VSMCs from autogenous vein grafts (1-4) week after transplantation(P<0.05, n=5).Conclusion: KCa is inhibited in autogenous vein graft, which account for vasospasm and intimal proliferation.

Internal Jugular Vein Graft after Inadvertent Severing of the Internal Carotid Artery during Carotid Endarterectomy and an Urgent Re-Exploration for Immediate Post-Operative Wound Site Bleeding: A Case Report

Carotid endarterectomy is a well-established treatment for preventing stroke in selected patients. Although there is debate over whether patch angioplasty or primary closure should be used to reconstruct the bifurcation after carotid endarterectomy, there is growing evidence in the literature in favor of patch angioplasty. When compared to primary closure, patch angioplasty during conventional carotid endarterectomy is suggested to lower the incidence of restenosis and recurrent ipsilateral stroke. Various materials have been used as a patch in this procedure, including the saphenous vein, synthetic patches, or less frequently, an internal jugular vein patch where extensive narrowing of the internal carotid artery is evident. In our case, we used an internal jugular vein graft after inadvertent severing the internal carotid artery (ICA) during carotid endarterectomy after the failure of reconstruction with a saphenous vein patch. We also encountered immediate postoperative reactionary hemorrhage following anesthetic reversal, necessitating an urgent re-exploration. The purpose of this case report is neither an attempt to suggest all patients need angioplasty nor to state that an internal jugular vein patch or graft is superior to synthetic material or saphenous veins;rather, it is an attempt to emphasize a potentially effective rescue way to reconstruct inadvertent extensive vascular injury during carotid endarterectomy.

Evaluation of corporal fibrosis in cadaveric pericardium and vein grafts for tunica albuginea substitution in rats

<abstract>Abstract Aim: To evaluate the degree of corporal fibrosis in rats with cadaveric pericardium or vein as grafting materials for tunica albuginea substitution. Materials and methods: Thirty male Sprague-Dawley rats (300 g-325 g) were divided at random into 3 groups of 10 animals each: group 1 was the sham-operated controls and groups 2 and 3 underwent wedge excision of tunica albuginea and replacement with cadaveric pericardium and vein grafts, respectively. Four months later, rats were sacrificed and the penis removed to assess the degree of fibrosis using RT PCR technique for TGP-β1 mRNA expression. The tissues were fixed in 10 % formalin, paraffin-embedded and stained with Masson's trichrome and Verhoff's van Giesen for collagen and elastic fibers. Results: Four months after grafting, there was minimal fibrosis surrounding the patch in the vein graft rats and moderate fibrosis in the pericardial graft rats. The degree of penile fibrosis in the pericardial graft rats was significantly higher than that in the controls (P<0.01), but in the vein graft rats it was not significantly different from that of the controls (P>0.05). Conclusion: The degree of penile fibrosis of cadaveric pericardial graft was significantly higher than that of the control group, while in the vein graft group it was comparable to the latter. The authors believe that the vein graft may be a more ideal substance to be used as the tunica albuginea substitute than the pericardial graft in the surgical treatment of Peyronie's disease.

Experimental Study of Tissue-type Plasminogen Activator Gene to Prevent Vein Grafts Stenosis

The effects of in vivo local expression of recombined human tissue-type plasminogen activator （t-PA） gene on the thrombosis and neointima formation of vein grafts were explored. Jugular vein-to-artery bypass grafting was performed on 72 New Zealand white rabbits. The rabbits were divided into 3 groups according to the different processing methods： transfected t-PA gene group （n = 24）, vector group （n= 24） and blank control group （n = 24）. Samples of vein grafts were harvested at different time points after surgery. The expression of t-PA gene in vein graft was detected by RT-PCR and the synthesis of t-PA protein by Western-Blot assay. The t-PA activity was measured by chromogenic substrate assay. The Cr51 labeled platelets accumulation in vein grafts was counted. The histopathological changes were compared in intima hyperplasia index among the three groups after operation. The results showed that at the 2^nd , 5^th , 14^th and 28^th day after operation, RT-PCR and Western-blot confirmed the expression of t-PA mRNA and protein at the site of gene transfer. The t-PA activity detected on the 2^nd, 5^th, 14^th and 28^th day in experimental group was 370. 63±59. 44, 344. 13±48. 47, 252.87±51.80 and 161.75±68. 94 U/g respectively, and disappeared on the 60^th day and undetected in the control groups. The number of platelets accumulated in the vein grafts in gene group, vector group and blank control group was （85. 04 ± 21.58） 10s, （225.87±85.13） 10^6 and （211.57±78.02） 10^6 respectively. The number of platelets accumulated in gene group was significantly fewer than that in the control groups. Morphometric analysis revealed that intimal hyperplasia was markedly reduced in the t-PA gene group as compared with that in the control groups. It was suggested that the local expression of t-PA gene in vein graft significantly inhibited the accumulation of platelets, thrombosis and concomitant intimal hyperplasia, by which stenosis of bypass graft could be prevented effectively.

Reducing intimal hyperplasia in vein grafts harvested by a no-touch harvesting technique

Objective To investigate the effect of no-touch harvesting technique in reducing vein graft intimal hyperplasia. Methods This longitudinal trial compared graft angiostenosis of two groups undergoing jugular vein to carotid artery interposition grafting in rabbit model. Conventional group:12 rabbits had their veins stripped,distended,and stored in heparinized saline solution. No-touch group:12 rabbits had veins removed with surrounding tissues,but were not distended,and stored in heparinized blood. The grafts were removed 4 weeks following grafting,and morphometry and immunohistochemistry assessment were performed. Results The intimal thickness,degree of angiostenosis and proliferation index of vascular smooth muscle cells of no-touch group were significantly reduced (P<0.01) compared with those of the conventional group. The proliferating cell nuclear antigen positive-staining cells were significantly increased (P<0.01) in the conventional group compared with whose in the no-touch group. Conclusion Harvesting the vein graft with no-touch harvesting technique could significantly reduce intimal hyperplasia of the vein graft.

Differentially Expressed MicroRNAs Associated with Vein Graft Restenosis in Rats

Objective:Intimal hyperplasia is the main cause of restenosis of vein grafts after venous transplantation.MicroRNAs are considered to play a role in vein graft restenosis;however,the expression profi le of microRNAs in neointima has not been reported in detail.We wanted to investigate the differentially expressed microRNAs in the restenosis of vein grafts in rats.Methods:We established a rat model for vein transplantation to explore the pathogenic roles of microRNAs during intimal hyperplasia.Hematoxylin and eosin staining was used to confi rm intimal hyperplasia in the vein grafts.Changes in microRNA expression in the vein grafts were detected 3 and 14 days after surgery by sequencing,reverse transcription–quantitative polymerase chain reaction,and bioinformatics analyses for functional annotation.Results:We detected 711 newly predicted microRNAs among all the comparisons.Among these comparisons,437 differentially expressed microRNAs were detected in the postoperative day 3 group versus the control group,265 were detected in the postoperative day 14 group versus the control group,and 158 were detected in the postoperative day 14 group versus the postoperative day 3 group.Pathway analysis revealed signifi cant enrichment of target genes that mediate Wnt,mitogen-activated protein kinase,vascular smooth muscle contraction,and regulation of actin cytoskeleton signaling.Conclusion:Our results provide insight into the pathogenesis of restenosis and will help develop novel targets in the prevention and treatment of vein graft restenosis.

Cavernous nerve reconstruction with autologous vein graft and platelet-derived growth factors

In this study, we investigated the feasibility of using autologous vein graft and platelet-derived growth factors to bridge transected cavernous nerve in a rat model. A short defect in the bilateral cavernous nerve was created and repaired with vein graft from the right jugular vein or vein graft plus platelet-derived growth factors. The 32 rats were divided into four groups, namely Group 1 - no repair as a negative control, Group 2 - vein graft alone, Group 3 - vein graft plus platelet-derived growth factors, and Group 4 - sham operation as a positive control. We evaluated nerve regeneration and functional recovery using retrograde tracing study with FluoroGold, Toluidine blue staining of cavernous nerve, and the intracavernous pressure at 3 months. Three months after surgery, rich FluoroGold-positive cells were observed in the sham and vein graft plus platelet-derived growth factors group, but very few were found in the no repair group. The number of myelinated axons of regenerated cavernous nerve and intracavernous pressure were increased obviously in the two vein graft groups, especially in the vein graft plus platelet-derived growth factors group. These findings confirm the feasibility of using autologous vein as guides for cavernous nerve regeneration, and the regeneration can be further enhanced when the vein is filled with Dlatelet-derived growth factors.

Effects of 3,3',4',5,7-pentamethylquercetin on intimal hyprerplasia vein grafts

Objective Pentamethylquercetin (PMQ) has a role in cardiovascular protection.We investigate the effects of 3,3 ’,4 ’,5,7 pentamethylquercetin,a derivative of PMQ,on intimal hyperplasia of the vein grafts in rats both in vivo and in vitro. Methods The proliferation of vascular smooth muscle cells (VSMC) was induced with Ang Ⅱ (0.1 μmol/L,24 h) while PMQ was administrated at six different dosages (0.1,0.3,1,3,10 and 30 μmoL/L).

Ewings sarcoma of patella:A rare entity treated with a novel technique of extensor mechanism reconstruction using tendoachilles auto graft

We report a case of Ewings sarcoma(ES) involving the patella in a young female. ES of patella is a rare entity. The patient was presented with anterior knee pain and swelling arising from the patella. She was treated with neoadjuvant chemotherapy followed by wide excision of the patella and reconstruction of the extensor mechanism using split tendoachilles auto graft. The patella is an uncommon site for primary or metastatic tumors of the bone. ES, though rare, should be included in the differential diagnosis of swellings arising from the patella. Auto graft from the tendoachilles is a good alternative for reconstructing the extensor mechanism of the knee.

Retrograde percutaneous coronary intervention via critically degenerated saphenous vein grafts for chronic total occlusion in native coronary arteries

We report the case of a 78-year-old woman with saphenous vein graft (SVG) disease and chronic total occlusion (CTO) in three native coronary arteries [left anterior descending artery (LAD), left circumflex artery, and the right coronary artery], who was successfully treated by percutaneous coronary intervention (PCI) using the retrograde approach via the critically degenerated SVGs. The patient, a 78-year-old woman, presented with sudden chest pain and dyspnea. She had previously undergone coronary artery bypass surgery using SVGs for the three vessels and percutaneous coronary intervention with sirolimuseluting stent placement in the posterolateral branch 13 and 3 years ago, respectively. Electrocardiography revealed ST-segment elevation in leads V1-4, whereas emergent coronary angiography revealed total occlusion in her native coronary arteries. Primary PCI was scheduled. A channel dilator was advanced very smoothly and safely into the distal site of the CTO lesion in the LAD, which showed complete occlusion in the proximal region, via an SVG that was temporally occluded four days earlier. A reverse controlled antegrade and retrograde tracking technique was used to successfully perform percutaneous recanalization. Subsequently, the other two native CTO lesions protected by critically degenerated SVGs were treated with retrograde intervention via the SVGs. The retrograde approach via critically degenerated SVGs is safe, reliable, and fast. If an SVG bypassing the native CTO lesion is critically degenerated, percutaneous coronary intervention should be performed via the SVG.

Percutaneous recanalization of total saphenous vein graft occlusion with excimer laser treatment

Patients presenting with recurrence of anginal symptoms after saphenous vein bypass surgery pose an increasingly frequent challenge.In general,approximately 40%to 50%of saphenous vein graft(SVG)will become diseased or occluded within the first ten years after surgery.[1]Because adverse clinical outcomes,such as high restenosis rates and distal embolization,have been reported,percutaneous coronary intervention(PCI)for SVG is not recommended as a first-line strategy.[2]Distal embolization occurs in 2%–17%of patients despite advances in therapy,including the utilization of embolic protection device(EPD),which may lead to increased mortality at both short follow-up and midterm follow-up.[3]However,these patients often associated with inappropriate anatomic characteristics of native vessel intervention including calcification,tortuosity,abundant plaque burden,and complex chronic total occlusion(CTO)lesions.Moreover,repeat coronary bypass surgery is an option but is technically more demanding and is associated with a higher mortality.Therefore,it can sometimes result in SVG stenosis being the only intervention option.This is why the recanalization of SVG lesions,especially totally occluded lesions,remains one of the most challenging procedures in interventional cardiology.

Experimental study on autogenous vein cuff alleviating arterial intimal hyperplasia

Objective: To explore the alleviation of arterial intimal hyperplasia and improvement of outflow by inserting an autogenous vein cuff between poly tetraflu oroethylene (PTFE) graft and arteri al an astomosis. Methods: Twenty-four hindlimbs of 12 mongrel dogs were randomly divided into control group and experimental group. Sole PTFE bypasses were made in the control group, an autologous vein cuff was inserted in the distal anastomosis in the experimental group. Eight weeks after operation, angiography was made and specimens were harvested, histomorphological studies under microscope and picture analysis with computer were carried out, scanning electromicroscopy on the vein cuff was made. Results: Angiography demonstrated the patency of control and experimental group was 16. 7% and 66. 7%, respectively; Computer gave the intimal thickness: (483. 5 ± 67. 3) μm and (147. 4 ± 38. 6) μm, respectively; no obvious change was seen in medial thickness; area of intimal hyperplasia was (5217 ± 1 123) (pixel) and (31 17 ± 890) (pixel), respectively, accounting (80. 9 ± 17. 2)% and (47. 7 ± 13. 7)% of the sectional area of vessel lumen. The interpositional vein was arteriolization. Conclusion: The interpositional autologous vein cuff can obviously mitigate the arterial intimal hyperplasia after PTFE bypasses, improving postoperative patency of vascular surgery.

Radial Artery and Saphenous Vein Grafts in Coronary Artery Bypass Surgery Comparison in Terms of Patient Symptoms

Background: The aim of this study is to compare radial artery with saphenous vein grafts which are widely used for coronary bypass, from views of patients’ satisfaction and postoperative findings. Methods: 42 isolated coronary bypass (CABG) patients performed during November 2012-April 2013 are included in the study. 30 days after the operation, in patients who had both RA and SV removal made responses to a questionnaire form which included 6 questions about symptoms of extremity. Results: After analyzing the responses and physical examination, there was no difference in terms of quality of life and usefulness of the extremity for daily use between two grafts. 2 patients (2%) have wound infection on the saphenous vein incision and additional surgical procedure was performed and a scar tissue has occurred. There was no statistically significance between uncomfortable symptoms and demographic data. Conclusion: Our study suggested that RA graft using showed a bit more comfortable and suitable effect against SV in our patients. We think that radial arterial grafts should be used more widely in coronary surgery with selected patients.

Autogenous inside-out versus standard vein and skeletal muscle-combined grafting for facial nerve repair

BACKGROUND： In the repair of nerve defects, collapse of the venous wall, as a result of vein grafting alone, could impede nerve regeneration. Therefore, vein lumens filled with muscle and nerve segments have been used to bridge nerve defects. OBJECTIVE： To compare the effects of autogenous, inside-out, vein-skeletal, muscle-combined grafting versus standard, vein-skeletal, muscle-combined grafting for the repair of facial nerve defects. DESIGN, TIME AND SETTING： A randomized, controlled, neuroanatomical, animal study was performed at the Animal Experimental Center and Laboratories of the Capital Medical University Xuanwu Hospital and the Peking Union Medical College Hospital from September 2007 to October 2008.MATERIALS： A total of 10 healthy, male, New Zealand rabbits, aged 6 months, were randomly assigned to inside-out, vein-skeletal, muscle-combined grafting and standard, vein-skeletal, muscle-combined grafting groups, with 5 rabbits in each group. METHODS： A 20-mm gap in the buccal branch of the right facial nerve was made in each animal, which was respectively repaired with inside-out, vein-skeletal, muscle-combined grafts or standard vein-skeletal muscle-combined grafts.MAIN OUTCOME MEASURES： At 6 months after implantation, evoked maximal compound muscle action potentials were recorded on bilateral facial nerves using electromyogram. Myelinated nerve fibers of the regenerating nerves were quantified using myelin sheath osmic acid staining. RESULTS： There was no significant difference between the groups in terms of ratios of bilateral amplitude and latency of compound muscle action potential （P 〉 0.05）. Moreover, morphology of regenerating nerves and quantity of myelinated nerve fibers were similar between the groups （P 〉 0.05）. CONCLUTION： Compared with standard vein grafting, the inside-out vein grafting did not significantly improve nerve regeneration. Therefore, it is not necessary to utilize inside-out vein grafting for the repair of nerve defects, in particular with the combined use of autogenous vein and skeletal muscle grafts.

A novel Nanocellulose-Gelatin-AS-IV external stent resists EndMT by activating autophagy to prevent restenosis of grafts

Vein grafts are widely used for coronary artery bypass grafting and hemodialysis access,but restenosis remains the"Achilles’heel"of these treatments.An extravascular stent is one wrapped around the vein graft and provides mechanical strength;it can buffer high arterial pressure and secondary vascular dilation of the vein to prevent restenosis.In this study,we developed a novel Nanocellulose-gelatin hydrogel,loaded with the drug Astragaloside IV(AS-IV)as an extravascular scaffold to investigate its ability to reduce restenosis.We found that the excellent physical and chemical properties of the drug AS-IV loaded Nanocellulose-gelatin hydrogel external stent limit graft vein expansion and make the stent biocompatible.We also found it can prevent restenosis by resisting endothelial-to-mesenchymal transition(EndMT)in vitro.It does so by activating autophagy,and AS-IV can enhance this effect both in vivo and in vitro.This study has added to existing research on the mechanism of extravascular stents in preventing restenosis of grafted veins.Furthermore,we have developed a novel extravascular stent for the prevention and treatment of restenosis.This will help optimize the clinical treatment plan of external stents and improve the prognosis in patients with vein grafts.

Ligamentum teres hepatis as a graft for portal and/or superior mesenteric vein reconstruction:From bench to bedside

BACKGROUND Pancreaticoduodenectomy combined with portal vein(PV)and/or superior mesenteric vein(SMV)resection in patients with pancreaticobiliary malignancy has become a common surgical procedure.There are various grafts currently used for PV and/or SMV reconstruction,but each of these grafts have certain limitations.Therefore,it is necessary to explore novel grafts that have an extensive resource pool,are low cost with good clinical application,and are without immune response rejection or additional damage to patients.AIM To observe the anatomical and histological characteristics of the ligamentum teres hepatis(LTH)and evaluate PV/SMV reconstruction using an autologous LTH graft in pancreaticobiliary malignancy patients.METHODS In 107 patients,the post-dilated length and diameter in resected LTH specimens were measured.The general structure of the LTH specimens was observed by hematoxylin and eosin(HE)staining.Collagen fibers(CFs),elastic fibers(EFs),and smooth muscle(SM)were visualized by Verhoeff-Van Gieson staining,and the expression of CD34,factor VIII-related antigen(FVIIIAg),endothelial nitric oxide synthase(eNOS),and tissue type plasminogen activator(t-PA)were detected using immunohistochemistry in LTH and PV(control)endothelial cells.PV and/or SMV reconstruction using the autologous LTH was conducted in 26 patients with pancreaticobiliary malignancies,and the outcomes were retrospectively analyzed.RESULTS The post-dilated length of LTH was 9.67±1.43 cm,and the diameter at a pressure of 30 cm H2O was 12.82±1.32 mm at the cranial end and 7.06±1.88 mm at the caudal end.Residual cavities with smooth tunica intima covered by endothelial cells were found in HE-stained LTH specimens.The relative amounts of EFs,CFs and SM in the LTH were similar to those in the PV[EF(%):11.23±3.40 vs 11.57±2.80,P=0.62;CF(%):33.51±7.71 vs 32.11±4.82,P=0.33;SM(%):15.61±5.26 vs 16.74±4.83,P=0.32].CD34,FVIIIAg,eNOS,and t-PA were expressed in both LTH and PV endothelial cells.The PV and/or SMV reconstructions were successfully completed in all patients.The overall morbidity and mortality rates were 38.46%and 7.69%,respectively.There were no graft-related complications.The postoperative vein stenosis rates at 2 wk,1 mo,3 mo and 1 year were 7.69%,11.54%,15.38%and 19.23%,respectively.In all 5 patients affected,the degree of vascular stenosis was less than half of the reconstructed vein lumen diameter(mild stenosis),and the vessels remained patent.CONCLUSION The anatomical and histological characteristics of LTH were similar to the PV and SMV.As such,the LTH can be used as an autologous graft for PV and/or SMV reconstruction in pancreaticobiliary malignancy patients who require PV and/or SMV resection.

Portal vein arterialization in 25 liver transplant recipients:A Latin American single-center experience

BACKGROUND Portal vein arterialization(PVA)has been used in liver transplantation(LT)to maximize oxygen delivery when arterial circulation is compromised or has been used as an alternative reperfusion technique for complex portal vein thrombosis(PVT).The effect of PVA on portal perfusion and primary graft dysfunction(PGD)has not been assessed.All patients receiving PVA and LT at the Fundacion Santa Fe de Bogota between 2011 and 2022 were analyzed.To account for the time-sensitive effects of graft perfusion,patients were classified into two groups:prereperfusion(pre-PVA),if the arterioportal anastomosis was performed before graft revascularization,and postreperfusion(post-PVA),if PVA was performed afterward.The pre-PVA rationale contemplated poor portal hemodynamics,severe vascular steal,or PVT.Post-PVA was considered if graft hypoperfusion became evident.Conservative interventions were attempted before PVA.