BACKGROUND Pediatric liver transplantation(LT)is the definitive treatment for end-stage liver disease and acute liver failure in children.However,graft size mismatch poses significant challenges,particularly in infant...BACKGROUND Pediatric liver transplantation(LT)is the definitive treatment for end-stage liver disease and acute liver failure in children.However,graft size mismatch poses significant challenges,particularly in infants weighing less than 10 kg.Large-forsize grafts can lead to severe complications,including vascular thrombosis and impaired graft perfusion.Surgical innovations,such as hyper-reduced left lateral segment(HRLLS)grafts and monosegmental grafts(MSG),offer viable solutions by tailoring graft size without compromising vascular or biliary integrity.AIM To analyze the techniques and outcomes of HRLLS and MSG grafts in pediatric liver trabsplantation.METHODS Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines,a comprehensive literature search was conducted across PubMed,Scopus,and Google Scholar,including studies up to February 2025.Eligible studies included case-control,observational,and randomized controlled trials reporting clinical outcomes of HRLLS,MSG,or reduced left lateral segment grafts(RLLS)in pediatric LT.The Joanna Briggs Institute Critical Appraisal Checklist was used for quality assessment.Meta-analysis was performed using MetaXL software to pool survival outcomes and assess complication profiles.RESULTS Eighteen studies involving various graft reduction techniques were included.Both HRLLS and MSG demonstrated comparable one-year survival rates exceeding 80%,with some studies reporting rates above 95%.Complications such as hepatic artery thrombosis,portal vein thrombosis,and sepsis were slightly more frequent in HRLLS/RLLS recipients but remained within acceptable limits.Meta-analysis revealed no significant differences in survivability between graft types.CONCLUSION HRLLS and MSG techniques enable successful liver transplantation in small pediatric recipients,achieving longterm outcomes comparable to standard approaches.These graft modification strategies expand donor pool utilization and optimize patient survival while mitigating large-for-size complications.展开更多
Liver transplantation(LT)has made significant progress in the treatment of end stage liver disease(ESLD).However,many patients still die from disease progression while awaiting transplantation.As the number of patient...Liver transplantation(LT)has made significant progress in the treatment of end stage liver disease(ESLD).However,many patients still die from disease progression while awaiting transplantation.As the number of patients on LT waiting lists is increasing,and the organ shortage crisis is obvious,various efforts have been made to increase the pool of available liver grafts[1].In addition to living donor liver transplantation(LDLT),improving the utilization rate of extended criteria donor(ECD)livers is an important way.However,under traditional cold storage,ECD livers are usually associated with a higher risk of ischemic biliary disease,early allograft dysfunction(EAD)or even primary nonfunction(PNF).The frequently described definition in the literature for ECD grafts generally includes elderly,steatotic,long cold ischemia time(CIT),grafts obtained from donation after circulatory death(DCD),split liver grafts,donors with increased risk of infectious disease transmission and prolonged donor intensive care unit stay[2].展开更多
Diabetic foot ulcers(DFUs)represents a significant public health issue,with a rising global prevalence and severe potential complications including amputation.Traditional treatments often fall short due to various lim...Diabetic foot ulcers(DFUs)represents a significant public health issue,with a rising global prevalence and severe potential complications including amputation.Traditional treatments often fall short due to various limitations such as high recurrence rates and extensive resource utilization.This editorial explores the innovative use of acellular fish skin grafts as a transformative approach in DFU management.Recent studies and a detailed case report highlight the efficacy of acellular fish skin grafts in accelerating wound closure,reducing dressing changes,and enhancing patient outcomes with a lower socio-economic burden.Despite their promise,challenges such as limited availability,patient acceptance,and the need for further research persist.Addressing these through more extensive randomized controlled trials and fostering a multidisciplinary treatment approach may optimize DFU care and reduce the global health burden associated with these complex wounds.展开更多
BACKGROUND Transcatheter aortic valve replacement(TAVR)can be performed through multiple access sites with the preferred approach being transfemoral.In patients with severe peripheral arterial disease and previous gra...BACKGROUND Transcatheter aortic valve replacement(TAVR)can be performed through multiple access sites with the preferred approach being transfemoral.In patients with severe peripheral arterial disease and previous grafts,the safety of transfemoral access via direct graft puncture,especially when performed twice within a short period,remains unclear compared to alternative access methods.We present a case demonstrating the safety and efficacy of direct graft puncture for transfemoral access during balloon aortic valvuloplasty(BAV)and TAVR.CASE SUMMARY An 82-year-old man presented with dyspnea on exertion.Echocardiogram was significant for severe aortic stenosis.Following a heart team discussion,the patient was scheduled for a balloon valvuloplasty followed by staged TAVR.Based on pre-TAVR computed tomography angiogram,the aortobifemoral graft was deemed as an appropriate access site.Micropuncture needle was used to access the right femoral artery graft,and the sheath was upscaled to 10 Fr.He underwent successful intervention to ostial left anterior descending and left circumflex arteries,and BAV with 22 mm Vida BAV balloon.Hemostasis was achieved using Perclose.For TAVR,an 8 Fr sheath was inserted via the right femoral bypass graft.The arteriotomy was pre-closed with two Perclose ProGlides and access was upsized to 18F Gore DrySeal.A 5Fr sheath was used for left femoral bypass graft access.Patient underwent successful TAVR with 29 mm CoreValve.Hemostasis was successfully achieved using 2 Perclose for right access site and one Perclose for left side with no postoperative bleeding complications.CONCLUSION BAV and TAVR are feasible and safe through a direct puncture of the aortofemoral bypass graft with successful hemostasis using Perclose.展开更多
BACKGROUND Tibial plateau fractures often require structural support for metaphyseal defects created during articular reduction.While autologous bone grafting has been utilized as the gold standard,bone substitutes of...BACKGROUND Tibial plateau fractures often require structural support for metaphyseal defects created during articular reduction.While autologous bone grafting has been utilized as the gold standard,bone substitutes offer advantages including reduced donor site morbidity.Our meta-analysis evaluated the comparative efficacy of these approaches across clinical and operative outcomes.AIM To conduct a systematic review and meta-analysis of randomized controlled trials comparing autologous bone grafts with bone substitutes for tibial plateau fractures.METHODS We conducted a systematic review and meta-analysis of randomized controlled trials comparing autologous bone grafts with bone substitutes for tibial plateau fractures.Primary outcomes included joint depression,secondary collapse rate,operative time,blood loss,and infection rate.Subgroup analyses were performed by fracture complexity,geographic region,and methodological factors.In addition to that,we also developed a combined outcome score integrating structural,procedural,and complication domains.RESULTS Seven randomized controlled trials with 424 patients(296 bone substitute,128 autograft)were included.No significant differences in joint depression or secondary collapse were observed across fracture complexity categories.Geographic variations were evident,with Western studies showing significantly higher risk of secondary collapse with autografts(risk ratio=1.45,P value=0.02).Both Western and Asian studies have demonstrated significantly reduced blood loss with bone substitutes(70-90 mL less),while operative time reduction was more significant in the Asian studies(23.65 vs 8.00 minutes,P value=0.04 for subgroup difference).The combined outcome score(standardized effect size-0.2481)favored bone substitutes,primarily due to procedural advantages.CONCLUSION Bone substitutes provide similar structural outcomes to autologous bone grafts while having better procedural advantages in tibial plateau fracture management.These findings support bone substitutes as a viable option across fracture patterns.Future studies should focus on specific bone substitute formulations and cost-effectiveness analyses.展开更多
The milestone reported by He et al.—demonstrating pig‐tohuman lung xenotransplantation in a brain‐dead recipient—is a seminal moment in organ xenografting.It extends the horizons of xenotransplantation beyond the ...The milestone reported by He et al.—demonstrating pig‐tohuman lung xenotransplantation in a brain‐dead recipient—is a seminal moment in organ xenografting.It extends the horizons of xenotransplantation beyond the breakthroughs achieved in porcine heart and kidney grafts and aligns with the emergent clinical data on porcine liver applications[1].展开更多
The aim of this review is to present and compare the various animal models of vascularized nerve grafts described in the literature as well as to summarize preclinical evidence for superior functional results compared...The aim of this review is to present and compare the various animal models of vascularized nerve grafts described in the literature as well as to summarize preclinical evidence for superior functional results compared to non-vascularized free nerve grafts. We also will present the state of the art on prefabricated vascularized nerve grafts. A systematic literature review on vascularized nerve graft models was conducted via the retrieval with the Pub Med database on March 30, 2019. Data on the animal, nerve, and vascularization model, the recipient bed, the evaluation time points and methods, and the results of the study results were extracted and analyzed from selected articles. The rat sciatic nerve was the most popular model for vascularized nerve grafts, followed by the rabbit;however, rabbit models allow for longer nerve grafts, which are suitable for translational evaluation, and produced more cautious results on the superiority of vascularized nerve grafts. Compared to free nerve grafts, vascularized nerve grafts have better early but similar long-term results, especially in an avascular bed. There are few studies on avascular receiving beds and prefabricated nerve grafts. The clinical translation potential of available animal models is limited, and current experimental knowledge cannot fully support that the differences between vascularized nerve grafts and free nerve grafts yield a clinical advantage that justifies the complexity of the procedure.展开更多
In this study,injectable bone graft putty samples were developed using fine and coarse melt-quenched 45S5 bioactive glass(BG)incorporated into a carrier system composed of glycerol and polyethylene glycol(PEG)with dif...In this study,injectable bone graft putty samples were developed using fine and coarse melt-quenched 45S5 bioactive glass(BG)incorporated into a carrier system composed of glycerol and polyethylene glycol(PEG)with different average molecular weights.Selected putty samples were further incorporated with varying amounts of Denosumab(5wt%-10wt%)to investigate its influence on rhe-ological behavior and flow properties using mathematical modeling.All PEG/glycerol/45S5-based putty samples exhibited viscoelastic behavior(storage modulus>loss modulus)and pseudoplastic behavior(n<1),with viscosity values required for optimal flow remaining below 1000 Pa∙s.Both viscosity and thixotropic area increased proportionally with higher BG content and smaller-sized BG particles.All putty samples showed more than 98%injectability through a 12G cannula,suggesting potential clinical suitability.However,injectability decreased with smaller cannulas,dropping to 34.7%-58.3%with a 19G cannula and further decreasing with a 23G cannula at higher BG contents.Incorporation of Denosumab preserved viscoelasticity and injectability but modified the flow behavior,shifting it from pseudo-plastic to more Newtonian with higher Denosumab content,while also reducing viscosity and thixotropic area values.Among all tested samples,putty containing a lower amount of Denosumab and smaller-sized BG exhibited the most suitable combination of injectability and rheological features.All putty samples were well described by both the Power law and Herschel-Bulkley rheological models(coeffi-cient of determination>0.95).This study highlights the influence of Denosumab on flowability and rheological relationships and sug-gests potential improvements in bioactivity through a dual synergistic effect of BG and Denosumab in minimally invasive bone graft sys-tems.展开更多
Large bone defects in load-bearing bone can result from tumor resection,osteomyelitis,trauma,and other factors.Although bone has the intrinsic potential to self-repair and regenerate,the repair of large bone defects w...Large bone defects in load-bearing bone can result from tumor resection,osteomyelitis,trauma,and other factors.Although bone has the intrinsic potential to self-repair and regenerate,the repair of large bone defects which exceed a certain critical size remains a substantial clinical challenge.Traditionally,repair methods involve using autologous or allogeneic bone tissue to replace the lost bone tissue at defect sites,and autogenous bone grafting remains the“gold standard”treatment.However,the application of traditional bone grafts is limited by drawbacks such as the quantity of extractable bone,donor-site morbidities,and the risk of rejection.In recent years,the clinical demand for alternatives to traditional bone grafts has promoted the development of novel bone-grafting substitutes.In addition to osteoconductivity and osteoinductivity,optimal mechanical properties have recently been the focus of efforts to improve the treatment success of novel bone-grafting alternatives in load-bearing bone defects,but most biomaterial synthetic scaffolds cannot provide sufficient mechanical strength.A fundamental challenge is to find an appropriate balance between mechanical and tissue-regeneration requirements.In this review,the use of traditional bone grafts in load-bearing bone defects,as well as their advantages and disadvantages,is summarized and reviewed.Furthermore,we highlight recent development strategies for novel bone grafts appropriate for load-bearing bone defects based on substance,structural,and functional bionics to provide ideas and directions for future research.展开更多
BACKGROUND Liver transplantation(LT)is the only curative,life-saving option for children and adults with end-stage liver disease.Due to the well-known shortage and heterogeneity of grafts,split LT(SLT)is an attractive...BACKGROUND Liver transplantation(LT)is the only curative,life-saving option for children and adults with end-stage liver disease.Due to the well-known shortage and heterogeneity of grafts,split LT(SLT)is an attractive strategy to expand the donor pool and reduce waitlist times.Given increased risk of cold ischemia time with SLT,machine perfusion represents a promising option to reduce it and optimize transplant logistics and outcomes.The present communication describes various possible combinations of procurement steps to perform SLT facilitated by placing one or both grafts on a normothermic machine perfusion(NMP)closed circuit device.CASE SUMMARY A 19-month-old female with biliary atresia after failed Kasai portoenterostomy and a 42-year-old woman with unresectable intrahepatic cholangiocarcinoma were selected as recipients for a SLT from a 17-year-old male donor.The SLT generated a left lateral segment and a right trisectional graft of appropriate volume for both recipients.After a mixed in-situ and ex-situ split,in order to improve logistics,the right trisectional graft was placed on a closed circuit NMP device,following an appropriate vascular reconstruction.Both grafts were implanted with excellent short-term outcomes.CONCLUSION Use of NMP with SLT for preservation prior to implantation allows not only for graft optimization but also for significant improvement of transplant logistics.We propose various models and standardization of logistic options for combining SLT with NMP to optimize graft availability and outcomes.展开更多
BACKGROUND Small-for-size grafts (SFSGs) in living donor liver transplantation (LDLT) could optimize donor postoperative outcomes and also expand the potential donor pool. Evidence on whether SFSGs would affect medium...BACKGROUND Small-for-size grafts (SFSGs) in living donor liver transplantation (LDLT) could optimize donor postoperative outcomes and also expand the potential donor pool. Evidence on whether SFSGs would affect medium-term and long-term recipient graft survival is lacking. AIM To evaluate the impact of small-for-size liver grafts on medium-term and longterm graft survival in adult to adult LDLT. METHODS A systematic review and meta-analysis were performed by searching eligible studies published before January 24, 2019 on PubMed, EMBASE, and Web of Science databases. The primary outcomes were 3-year and 5-year graft survival. Incidence of small-for-size syndrome and short term mortality were also extracted. RESULTS This meta-analysis is reported according to the guidelines of the PRISMA 2009 Statement. Seven retrospective observational studies with a total of 1821 LDLT recipients were included in the meta-analysis. SFSG is associated with significantly poorer medium-term graft survival. The pooled odds ratio for 3-year graft survival was 1.58 [95% confidence interval 1.10-2.29, P = 0.014]. On the other hand, pooled results of the studies showed that SFSG had no significant discriminatory effect on 5-year graft survival with an odds ratio of 1.31 (95% confidence interval 0.87-1.97, P = 0.199). Furthermore, incidence of small-for-size syndrome detected in recipients of SFSG ranged from 0-11.4% in the included studies. CONCLUSION SFSG is associated with inferior medium-term but not long-term graft survival. Comparable long-term graft survival based on liver graft size shows that smaller grafts could be accepted for LDLT with appropriate flow modulatory measures. Close follow-up for graft function is warranted within 3 years after liver transplantation.展开更多
The scarcity of available organs and the gap between supply and demand continue to be the main limitations of liver transplantation. To relieve the organ shortage, current transplant strategies have implemented extend...The scarcity of available organs and the gap between supply and demand continue to be the main limitations of liver transplantation. To relieve the organ shortage, current transplant strategies have implemented extended criteria, which include the use of liver from patients with signs of past or present hepatitis B virus(HBV) infection. While the use of liver grafts from donors with evidence of past HBV infection is quite limited, some data have been collected regarding the feasibility of transplanting a liver graft from a hepatitis B surface antigen(HBs Ag) positive donor. The aim of the present work was to review the literature regarding liver transplants from HBs Ag-positive donors. A total of 17 studies were identified by a search in Medline. To date, HBs Ag positive grafts have preferentially been allocated to HBs Ag positive recipients. The large majority of these patients continue to be HBs Ag positive despite the use of immunoglobulin, and infection prevention can only be guaranteed by using antiviral prophylaxis. Although serological persistence is evident, no significant HBV-related disease has been observed, except in patients coinfected with delta virus. Consistently less data are available for HBs Ag negative recipients, although they are mostly promising. HBs Agpositive grafts could be an additional organ source for liver transplantation, provided that the risk of reinfection/reactivation is properly prevented.展开更多
We previously demonstrated that overexpression of tropomyosin receptor kinase A(TrkA)promotes the survival and Schwann celllike differentiation of bone marrow stromal stem cells in nerve grafts,thereby enhancing the r...We previously demonstrated that overexpression of tropomyosin receptor kinase A(TrkA)promotes the survival and Schwann celllike differentiation of bone marrow stromal stem cells in nerve grafts,thereby enhancing the regeneration and functional recovery of the peripheral nerve.In the present study,we investigated the molecular mechanisms underlying the neuroprotective effects of TrkA in bone marrow stromal stem cells seeded into nerve grafts.Bone marrow stromal stem cells from Sprague-Dawley rats were infected with recombinant lentivirus vector expressing rat TrkA,TrkA-shRNA or the respective control.The cells were then seeded into allogeneic rat acellular nerve allografts for bridging a 1-cm right sciatic nerve defect.Then,8 weeks after surgery,hematoxylin and eosin staining showed that compared with the control groups,the cells and fibers in the TrkA overexpressing group were more densely and uniformly arranged,whereas they were relatively sparse and arranged in a disordered manner in the TrkA-shRNA group.Western blot assay showed that compared with the control groups,the TrkA overexpressing group had higher expression of the myelin marker,myelin basic protein and the axonal marker neurofilament 200.The TrkA overexpressing group also had higher levels of various signaling molecules,including TrkA,pTrkA(Tyr490),extracellular signal-regulated kinases 1/2(Erkl/2),pErk1/2(Thr202/Tyr204),and the anti-apoptotic proteins Bcl-2 and Bcl-xL.In contrast,these proteins were downregulated,while the pro-apoptotic factors Bax and Bad were upregulated,in the TrkA-shRNA group.The levels of the TrkA effectors Akt and pAkt(Ser473)were not different among the groups.These results suggest that TrkA enhances the survival and regenerative capacity of bone marrow stromal stem cells through upregulation of the Erk/Bcl-2 pathway.All procedures were approved by the Animal Ethical and Welfare Committee of Shenzhen University,China in December 2014(approval No.AEWC-2014-001219).展开更多
AIM: To evaluate the dual-graft living donor liver transplantation (LDLT) with ultrasonography, with special emphasis on the postoperative complications. METHODS: From January 2002 to August 2007, 110 adult-to-adult L...AIM: To evaluate the dual-graft living donor liver transplantation (LDLT) with ultrasonography, with special emphasis on the postoperative complications. METHODS: From January 2002 to August 2007, 110 adult-to-adult LDLTs were performed in West China Hos- pital of Sichuan University. Among them, dual-graft implantations were performed in six patients. Sonographic findings of the patients were retrospectively reviewed. RESULTS: All the six recipients survived the dual-graft adult-to-adult LDLT surgery. All had pleural effusion. Four patients had episodes of postoperative abdominal complications, including fluid collection between the grafts in three patients, intrahepatic biliary dilatation in two, hepatofugal portal flow of the left lobe in two, and atrophy of the left lobe in one. CONCLUSION: Although dual-graft LDLT takes more efforts and is technically complicated, it is safely feasible. Postoperative sonographic monitoring of the recipient is important.展开更多
Liver transplantation(LT) is one of the most effective treatments for end-stage liver disease caused by related risk factors when liver resection is contraindicated. Additionally,despite the decrease in the prevalence...Liver transplantation(LT) is one of the most effective treatments for end-stage liver disease caused by related risk factors when liver resection is contraindicated. Additionally,despite the decrease in the prevalence of hepatitis B virus(HBV) over the past two decades,the absolute number of HBs Ag-positive people has increased,leading to an increase in HBV-related liver cirrhosis and hepatocellular carcinoma. Consequently,a large demand exists for LT. While the wait time for patients on the donor list is,to some degree,shorter due to the development of living donor liver transplantation(LDLT),there is still a shortage of liver grafts. Furthermore,recipients often suffer from emergent conditions,such as liver dysfunction or even hepatic encephalopathy,which can lead to a limited choice in grafts. To expand the pool of available liver grafts,one option is the use of organs that were previously considered "unusable" by many,which are often labeled "marginal" organs. Many previous studies have reported on the possibilities of using marginal grafts in orthotopic LT; however,there is still a lack of discussion on this topic,especially regarding the feasibility of using marginal grafts in LDLT. Therefore,the present review aimed to summarize the feasibility of using marginal liver grafts for LDLT and discuss the possibility of expanding the application of these grafts.展开更多
AIM To compare the effect of University of Wisconsin(UW) solution with or without metformin, an AMP-activated protein kinase(AMPK) activator, for preserving standard and marginal liver grafts of young and aged rats ex...AIM To compare the effect of University of Wisconsin(UW) solution with or without metformin, an AMP-activated protein kinase(AMPK) activator, for preserving standard and marginal liver grafts of young and aged rats ex vivo by hypothermic machine perfusion(HMP).METHODS Eighteen young(4 mo old) and 18 aged(17 mo old)healthy male SD rats were selected and randomly divided into three groups: control group, UW solution perfusion group(UWP), and UW solution with metformin perfusion group(MUWP). Aspartate aminotransferase(AST), alanine aminotransferase(ALT), lactate dehydrogenase(LDH), interleukin-18(IL-18), and tumor necrosis factor-alpha(TNF-α) in the perfused liquid were tested. The expression levels of AMPK and endothelial nitric oxide synthase(e NOS) in liver sinusoidal endothelial cells were also examined.Additionally, microscopic evaluation of the harvested perfused liver tissue samples was done. RESULTS AST, ALT, LDH, IL-18 and TNF-α levels in the young and aged liver-perfused liquid were, respectively,significantly lower in the MUWP group than in the UWP group(P < 0.05), but no significant differences were found between the young and aged MUWP groups.Metformin increased the expression of AMPK and e NOS protein levels, and promoted the extracellular release of nitric oxide through activation of the AMPK-e NOS mediated pathway. Histological examination revealed that in the MUWP group, the extent of liver cells and tissue damage was significantly reduced compared with the UWP group.CONCLUSION The addition of metformin to the UW preservative solution for ex vivo HMP can reduce rat liver injury during cold ischemia, with significant protective effects on livers, especially of aged rats.展开更多
This study reviews the state of the art in structural design and the corresponding mechanical behaviours of composite vascular grafts. We critically analyse surface and matrix designs composed of layered, embedded, an...This study reviews the state of the art in structural design and the corresponding mechanical behaviours of composite vascular grafts. We critically analyse surface and matrix designs composed of layered, embedded, and hybrid structures along the radial and longitudinal directions;materials and manufacturing techniques, such as tissue engineering and the use of textiles or their combinations;and the corresponding mechanical behaviours of composite vascular grafts in terms of their physical–mechanical properties, especially their stress–strain relationships and elastic recovery. The role of computational studies is discussed with respect to optimizing the geometrics designs and the corresponding mechanical behaviours to satisfy specialized applications, such as those for the aorta and its subparts. Natural and synthetic endothelial materials yield improvements in the mechanical and biological compliance of composite graft surfaces with host arteries. Moreover,the diameter, wall thickness, stiffness, compliance, tensile strength, elasticity, and burst strength of the graft matrix are determined depending on the application and the patient. For composite vascular grafts, hybrid architectures are recommended featuring multiple layers, dimensions, and materials to achieve the desired optimal flexibility and function for complying with user-specific requirements. Rapidly emerging artificial intelligence and big data techniques for diagnostics and the threedimensional(3D) manufacturing of vascular grafts will likely yield highly compliant, subject-specific, long-lasting, and economical vascular grafts in the near-future.展开更多
Corneal transplantation is the most common surgical procedure amongst solid organ transplants with a high survival rate of 86% at 1-year post-grafting. This high success rate has been attributed to the immune privileg...Corneal transplantation is the most common surgical procedure amongst solid organ transplants with a high survival rate of 86% at 1-year post-grafting. This high success rate has been attributed to the immune privilege of the eye. However, mechanisms originally thought to promote immune privilege, such as the lack of antigen presenting cells and vessels in the cornea, are challenged by recent studies. Nevertheless, the immunological and physiological features of the cornea promoting a relatively weak alloimmune response is likely responsible for the high survival rate in "low-risk" settings. Furthermore, although corneal graft survival in "lowrisk" recipients is favourable, the prognosis in "high-risk" recipients for corneal graft is poor. In "high-risk" grafts, the process of indirect allorecognition is accelerated by the enhanced innate and adaptive immune responses due to pre-existing inflammation and neovascularization of the host bed. This leads to the irreversible rejection of the allograft and ultimately graft failure. Many therapeutic measures are being tested in pre-clinical and clinical studies to counter the immunological challenge of "high-risk" recipients. Despite the prevailing dogma, recent data suggest that tissue matching together with use of systemic immunosuppression may increase the likelihood of graft acceptance in "high-risk" recipients. However, immunosuppressive drugs are accompanied with intolerance/side effects and toxicity, and therefore, novel cell-based therapies are in development which target host immune cells and restore immune homeostasis without significant side effect of treatment. In addition, developments in regenerative medicinemay be able to solve both important short comings of allotransplantation:(1) graft rejection and ultimate graft failure; and(2) the lack of suitable donor corneas. The advances in technology and research indicate that wider therapeutic choices for patients may be available to address the worldwide problem of corneal blindness in both "low-risk" and "high-risk" hosts.展开更多
Coronary artery bypass grafting surgery is increasingly being carried out on patients with multi-vessel coronary artery disease,but the best grafting candidate for non-left anterior descending coronary arteries is unc...Coronary artery bypass grafting surgery is increasingly being carried out on patients with multi-vessel coronary artery disease,but the best grafting candidate for non-left anterior descending coronary arteries is unclear.This research sought to systematically compare the efficacies and safeties of coronary bypass with radial artery and other available grafts.A systematic literature retrieval was performed for all clinical trials comparing the outcomes of coronary artery bypass surgery with radial artery and other grafts in PubMed,EMBASE,and the Cochrane Library.Seven eligible clinical studies,comparing radial artery and great saphenous vein grafts,were found between 1966 and 2010:one prospective non-randomized and six prospective randomized trials.The pooling analysis obtained a relative risk of 0.507 (P<0.05) of graft occlusion in radial arteries compared with great saphenous veins.There was a significantly lower infection rate in arms (i.e.,harvest sites for radial arteries) relative to legs (harvest sites for veins),with a pooled relative risk of 0.140 (P<0.05).From the reports on mortality after follow-up ranging from one year to six years,there was no significant difference in mortality between the two graft types (P=0.927).In addition,four cohort controlled trials for radial and right internal thoracic artery grafts were included.The radial graft was associated with less cardiac related events relative to the right internal thoracic artery graft (P=0.014),but with comparable mortality and comparable rates of repeat percutaneous transluminal coronary angioplasty.Subjects with radial arteries seemed to have a lower occlusion rate and a lower graft harvest site infection rate than those with great saphenous veins.Moreover there were fewer cardiac related events with radial arteries relative to the right internal thoracic artery grafts.More studies are needed to confirm these findings concerning the favorable outcomes of coronary artery bypass grafting with radial arteries on long-term patency and mortality.展开更多
BACKGROUND: The source of nerve allograft enriches. We may choose expediently nerve allograft to repair injured nerve and the structure of choice nerve homology or similar with the injured nerve, but the immunological...BACKGROUND: The source of nerve allograft enriches. We may choose expediently nerve allograft to repair injured nerve and the structure of choice nerve homology or similar with the injured nerve, but the immunological rejection limits the clinical application of nerve allograft. The ideal substitute of autograft never is researching. OBJECTIVE: In this experiment, Triton X-100 was used to extract the Schwann cells and myelin sheaths of allograft nerve and obtain the inartificial and eliminated antigenicity nerve-transplanter (nerve grafts). DESIGN: Controlled experiment. SETTING: Department of Hand Surgery, the Third Affiliated Hospital of Hebei Medical University; Second Department of Orthopedics, Fourth Center Hospital of Tianjin. MATERIALS: Thirty health New Zealand big ear white rabbit, of either sex (gender), weighing 2000-3000 g, were provided by the Center of Experimental Animal of Hebei Medical University. TritonX-100 was offered by SIGMA Company. METHODS: The experiment was carried out at the Central Laboratory of the Third Affiliated Hospital of Hebei Medical University from December 2003 to December 2004. Sixty pieces of sciatic nerves, 10-mm-long nerve segment, which were taken from 30 rabbits, were incised. They were randomly divided into chemical extraction group (n =50) and control group (n =10). In the chemical extraction groups, the nerves were put into 3% Triton X-100 solution. They were treated with Triton X-100 for 12 hours, 24 hours, 48 hours, 96 hours and 1 week, respectively. They were examined in every period. The control groups did not treated with anything. ① Respectively two segments of nerve by 2 mm length were taken from each nerve in the every periods. ② The laminin immunohistochemical stained sections were performed with image acquisition and analyzed with multicolor pathological image analysis system. Measured the laminin antibody reaction part of each section and computed laminin average gray degrees of the unit area. All dates were analyzed by SPSS 10.0 software. MAIN OUTCOME MEASURES: ① General observation and histological observation in two groups; ② Compared with laminin average gray degrees of the unit area in each section. RESULTS: ① General observation: In the control groups, fresh nerve was polish, rigidity and elasticity. After the nerves were chemical extracted, the floccules was seen at two ends and around of the nerves. The nerves being extraction presented ivory and lackluster. Its diameter and length compared reduced, tenderness and tenacity with the fresh nerve. Observed by light microscope, Schwann cells, myelin sheaths and basement membrane distribute uniformly in control groups. After the nerves were extracted, Schwann cells and myelin sheaths disappeared. Basement membrane presented barrier array in longitudinal sections. Between the membranes was the basement membrane tube. Observed with scanning electron microscope, the basement membrane tubes composed by collagen fibers were remained and collagen fibers maintained their former position, form and structure. Further, the structure of membrane was seen in the tubes. It was Schwann cells basement membrane. ② In chemical extraction groups, laminin average gray degrees of the unit area were 140.1±3.41 (12 hours), 142.1±3.14 (24 hours), 142.1±3.14 (48 hours), 140.4±4.03 (96 hours), 141.7±2.62 (1 week). In the control groups, laminin average gray degree of the unit area was 142.7±7.24. There were not significant differences among the groups (P > 0.05). CONCLUSION: The method of chemical extraction by using of Triton X-100 may be an ideal measure for preparing tissue-engineered nerve-transplanter and reserved the live of laminin in the basement membrane.展开更多
文摘BACKGROUND Pediatric liver transplantation(LT)is the definitive treatment for end-stage liver disease and acute liver failure in children.However,graft size mismatch poses significant challenges,particularly in infants weighing less than 10 kg.Large-forsize grafts can lead to severe complications,including vascular thrombosis and impaired graft perfusion.Surgical innovations,such as hyper-reduced left lateral segment(HRLLS)grafts and monosegmental grafts(MSG),offer viable solutions by tailoring graft size without compromising vascular or biliary integrity.AIM To analyze the techniques and outcomes of HRLLS and MSG grafts in pediatric liver trabsplantation.METHODS Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines,a comprehensive literature search was conducted across PubMed,Scopus,and Google Scholar,including studies up to February 2025.Eligible studies included case-control,observational,and randomized controlled trials reporting clinical outcomes of HRLLS,MSG,or reduced left lateral segment grafts(RLLS)in pediatric LT.The Joanna Briggs Institute Critical Appraisal Checklist was used for quality assessment.Meta-analysis was performed using MetaXL software to pool survival outcomes and assess complication profiles.RESULTS Eighteen studies involving various graft reduction techniques were included.Both HRLLS and MSG demonstrated comparable one-year survival rates exceeding 80%,with some studies reporting rates above 95%.Complications such as hepatic artery thrombosis,portal vein thrombosis,and sepsis were slightly more frequent in HRLLS/RLLS recipients but remained within acceptable limits.Meta-analysis revealed no significant differences in survivability between graft types.CONCLUSION HRLLS and MSG techniques enable successful liver transplantation in small pediatric recipients,achieving longterm outcomes comparable to standard approaches.These graft modification strategies expand donor pool utilization and optimize patient survival while mitigating large-for-size complications.
文摘Liver transplantation(LT)has made significant progress in the treatment of end stage liver disease(ESLD).However,many patients still die from disease progression while awaiting transplantation.As the number of patients on LT waiting lists is increasing,and the organ shortage crisis is obvious,various efforts have been made to increase the pool of available liver grafts[1].In addition to living donor liver transplantation(LDLT),improving the utilization rate of extended criteria donor(ECD)livers is an important way.However,under traditional cold storage,ECD livers are usually associated with a higher risk of ischemic biliary disease,early allograft dysfunction(EAD)or even primary nonfunction(PNF).The frequently described definition in the literature for ECD grafts generally includes elderly,steatotic,long cold ischemia time(CIT),grafts obtained from donation after circulatory death(DCD),split liver grafts,donors with increased risk of infectious disease transmission and prolonged donor intensive care unit stay[2].
基金Supported by the Zhejiang Medical Technology Project,No.2022RC009 and No.2024KY645.
文摘Diabetic foot ulcers(DFUs)represents a significant public health issue,with a rising global prevalence and severe potential complications including amputation.Traditional treatments often fall short due to various limitations such as high recurrence rates and extensive resource utilization.This editorial explores the innovative use of acellular fish skin grafts as a transformative approach in DFU management.Recent studies and a detailed case report highlight the efficacy of acellular fish skin grafts in accelerating wound closure,reducing dressing changes,and enhancing patient outcomes with a lower socio-economic burden.Despite their promise,challenges such as limited availability,patient acceptance,and the need for further research persist.Addressing these through more extensive randomized controlled trials and fostering a multidisciplinary treatment approach may optimize DFU care and reduce the global health burden associated with these complex wounds.
文摘BACKGROUND Transcatheter aortic valve replacement(TAVR)can be performed through multiple access sites with the preferred approach being transfemoral.In patients with severe peripheral arterial disease and previous grafts,the safety of transfemoral access via direct graft puncture,especially when performed twice within a short period,remains unclear compared to alternative access methods.We present a case demonstrating the safety and efficacy of direct graft puncture for transfemoral access during balloon aortic valvuloplasty(BAV)and TAVR.CASE SUMMARY An 82-year-old man presented with dyspnea on exertion.Echocardiogram was significant for severe aortic stenosis.Following a heart team discussion,the patient was scheduled for a balloon valvuloplasty followed by staged TAVR.Based on pre-TAVR computed tomography angiogram,the aortobifemoral graft was deemed as an appropriate access site.Micropuncture needle was used to access the right femoral artery graft,and the sheath was upscaled to 10 Fr.He underwent successful intervention to ostial left anterior descending and left circumflex arteries,and BAV with 22 mm Vida BAV balloon.Hemostasis was achieved using Perclose.For TAVR,an 8 Fr sheath was inserted via the right femoral bypass graft.The arteriotomy was pre-closed with two Perclose ProGlides and access was upsized to 18F Gore DrySeal.A 5Fr sheath was used for left femoral bypass graft access.Patient underwent successful TAVR with 29 mm CoreValve.Hemostasis was successfully achieved using 2 Perclose for right access site and one Perclose for left side with no postoperative bleeding complications.CONCLUSION BAV and TAVR are feasible and safe through a direct puncture of the aortofemoral bypass graft with successful hemostasis using Perclose.
文摘BACKGROUND Tibial plateau fractures often require structural support for metaphyseal defects created during articular reduction.While autologous bone grafting has been utilized as the gold standard,bone substitutes offer advantages including reduced donor site morbidity.Our meta-analysis evaluated the comparative efficacy of these approaches across clinical and operative outcomes.AIM To conduct a systematic review and meta-analysis of randomized controlled trials comparing autologous bone grafts with bone substitutes for tibial plateau fractures.METHODS We conducted a systematic review and meta-analysis of randomized controlled trials comparing autologous bone grafts with bone substitutes for tibial plateau fractures.Primary outcomes included joint depression,secondary collapse rate,operative time,blood loss,and infection rate.Subgroup analyses were performed by fracture complexity,geographic region,and methodological factors.In addition to that,we also developed a combined outcome score integrating structural,procedural,and complication domains.RESULTS Seven randomized controlled trials with 424 patients(296 bone substitute,128 autograft)were included.No significant differences in joint depression or secondary collapse were observed across fracture complexity categories.Geographic variations were evident,with Western studies showing significantly higher risk of secondary collapse with autografts(risk ratio=1.45,P value=0.02).Both Western and Asian studies have demonstrated significantly reduced blood loss with bone substitutes(70-90 mL less),while operative time reduction was more significant in the Asian studies(23.65 vs 8.00 minutes,P value=0.04 for subgroup difference).The combined outcome score(standardized effect size-0.2481)favored bone substitutes,primarily due to procedural advantages.CONCLUSION Bone substitutes provide similar structural outcomes to autologous bone grafts while having better procedural advantages in tibial plateau fracture management.These findings support bone substitutes as a viable option across fracture patterns.Future studies should focus on specific bone substitute formulations and cost-effectiveness analyses.
文摘The milestone reported by He et al.—demonstrating pig‐tohuman lung xenotransplantation in a brain‐dead recipient—is a seminal moment in organ xenografting.It extends the horizons of xenotransplantation beyond the breakthroughs achieved in porcine heart and kidney grafts and aligns with the emergent clinical data on porcine liver applications[1].
文摘The aim of this review is to present and compare the various animal models of vascularized nerve grafts described in the literature as well as to summarize preclinical evidence for superior functional results compared to non-vascularized free nerve grafts. We also will present the state of the art on prefabricated vascularized nerve grafts. A systematic literature review on vascularized nerve graft models was conducted via the retrieval with the Pub Med database on March 30, 2019. Data on the animal, nerve, and vascularization model, the recipient bed, the evaluation time points and methods, and the results of the study results were extracted and analyzed from selected articles. The rat sciatic nerve was the most popular model for vascularized nerve grafts, followed by the rabbit;however, rabbit models allow for longer nerve grafts, which are suitable for translational evaluation, and produced more cautious results on the superiority of vascularized nerve grafts. Compared to free nerve grafts, vascularized nerve grafts have better early but similar long-term results, especially in an avascular bed. There are few studies on avascular receiving beds and prefabricated nerve grafts. The clinical translation potential of available animal models is limited, and current experimental knowledge cannot fully support that the differences between vascularized nerve grafts and free nerve grafts yield a clinical advantage that justifies the complexity of the procedure.
基金supported by Yildiz Technical University Scientific Research Projects Coordination Unit under project number FBA-2023-5377support from the Scientific and Technological Research Council of Turkey(TUBITAK)under the BIDEB/2211-A National PhD Scholarship Program and 2250-Performance-Based Scholarships Program for PhD.
文摘In this study,injectable bone graft putty samples were developed using fine and coarse melt-quenched 45S5 bioactive glass(BG)incorporated into a carrier system composed of glycerol and polyethylene glycol(PEG)with different average molecular weights.Selected putty samples were further incorporated with varying amounts of Denosumab(5wt%-10wt%)to investigate its influence on rhe-ological behavior and flow properties using mathematical modeling.All PEG/glycerol/45S5-based putty samples exhibited viscoelastic behavior(storage modulus>loss modulus)and pseudoplastic behavior(n<1),with viscosity values required for optimal flow remaining below 1000 Pa∙s.Both viscosity and thixotropic area increased proportionally with higher BG content and smaller-sized BG particles.All putty samples showed more than 98%injectability through a 12G cannula,suggesting potential clinical suitability.However,injectability decreased with smaller cannulas,dropping to 34.7%-58.3%with a 19G cannula and further decreasing with a 23G cannula at higher BG contents.Incorporation of Denosumab preserved viscoelasticity and injectability but modified the flow behavior,shifting it from pseudo-plastic to more Newtonian with higher Denosumab content,while also reducing viscosity and thixotropic area values.Among all tested samples,putty containing a lower amount of Denosumab and smaller-sized BG exhibited the most suitable combination of injectability and rheological features.All putty samples were well described by both the Power law and Herschel-Bulkley rheological models(coeffi-cient of determination>0.95).This study highlights the influence of Denosumab on flowability and rheological relationships and sug-gests potential improvements in bioactivity through a dual synergistic effect of BG and Denosumab in minimally invasive bone graft sys-tems.
基金supported by the National Natural Science Foundation of China(No.82202450).
文摘Large bone defects in load-bearing bone can result from tumor resection,osteomyelitis,trauma,and other factors.Although bone has the intrinsic potential to self-repair and regenerate,the repair of large bone defects which exceed a certain critical size remains a substantial clinical challenge.Traditionally,repair methods involve using autologous or allogeneic bone tissue to replace the lost bone tissue at defect sites,and autogenous bone grafting remains the“gold standard”treatment.However,the application of traditional bone grafts is limited by drawbacks such as the quantity of extractable bone,donor-site morbidities,and the risk of rejection.In recent years,the clinical demand for alternatives to traditional bone grafts has promoted the development of novel bone-grafting substitutes.In addition to osteoconductivity and osteoinductivity,optimal mechanical properties have recently been the focus of efforts to improve the treatment success of novel bone-grafting alternatives in load-bearing bone defects,but most biomaterial synthetic scaffolds cannot provide sufficient mechanical strength.A fundamental challenge is to find an appropriate balance between mechanical and tissue-regeneration requirements.In this review,the use of traditional bone grafts in load-bearing bone defects,as well as their advantages and disadvantages,is summarized and reviewed.Furthermore,we highlight recent development strategies for novel bone grafts appropriate for load-bearing bone defects based on substance,structural,and functional bionics to provide ideas and directions for future research.
文摘BACKGROUND Liver transplantation(LT)is the only curative,life-saving option for children and adults with end-stage liver disease.Due to the well-known shortage and heterogeneity of grafts,split LT(SLT)is an attractive strategy to expand the donor pool and reduce waitlist times.Given increased risk of cold ischemia time with SLT,machine perfusion represents a promising option to reduce it and optimize transplant logistics and outcomes.The present communication describes various possible combinations of procurement steps to perform SLT facilitated by placing one or both grafts on a normothermic machine perfusion(NMP)closed circuit device.CASE SUMMARY A 19-month-old female with biliary atresia after failed Kasai portoenterostomy and a 42-year-old woman with unresectable intrahepatic cholangiocarcinoma were selected as recipients for a SLT from a 17-year-old male donor.The SLT generated a left lateral segment and a right trisectional graft of appropriate volume for both recipients.After a mixed in-situ and ex-situ split,in order to improve logistics,the right trisectional graft was placed on a closed circuit NMP device,following an appropriate vascular reconstruction.Both grafts were implanted with excellent short-term outcomes.CONCLUSION Use of NMP with SLT for preservation prior to implantation allows not only for graft optimization but also for significant improvement of transplant logistics.We propose various models and standardization of logistic options for combining SLT with NMP to optimize graft availability and outcomes.
文摘BACKGROUND Small-for-size grafts (SFSGs) in living donor liver transplantation (LDLT) could optimize donor postoperative outcomes and also expand the potential donor pool. Evidence on whether SFSGs would affect medium-term and long-term recipient graft survival is lacking. AIM To evaluate the impact of small-for-size liver grafts on medium-term and longterm graft survival in adult to adult LDLT. METHODS A systematic review and meta-analysis were performed by searching eligible studies published before January 24, 2019 on PubMed, EMBASE, and Web of Science databases. The primary outcomes were 3-year and 5-year graft survival. Incidence of small-for-size syndrome and short term mortality were also extracted. RESULTS This meta-analysis is reported according to the guidelines of the PRISMA 2009 Statement. Seven retrospective observational studies with a total of 1821 LDLT recipients were included in the meta-analysis. SFSG is associated with significantly poorer medium-term graft survival. The pooled odds ratio for 3-year graft survival was 1.58 [95% confidence interval 1.10-2.29, P = 0.014]. On the other hand, pooled results of the studies showed that SFSG had no significant discriminatory effect on 5-year graft survival with an odds ratio of 1.31 (95% confidence interval 0.87-1.97, P = 0.199). Furthermore, incidence of small-for-size syndrome detected in recipients of SFSG ranged from 0-11.4% in the included studies. CONCLUSION SFSG is associated with inferior medium-term but not long-term graft survival. Comparable long-term graft survival based on liver graft size shows that smaller grafts could be accepted for LDLT with appropriate flow modulatory measures. Close follow-up for graft function is warranted within 3 years after liver transplantation.
文摘The scarcity of available organs and the gap between supply and demand continue to be the main limitations of liver transplantation. To relieve the organ shortage, current transplant strategies have implemented extended criteria, which include the use of liver from patients with signs of past or present hepatitis B virus(HBV) infection. While the use of liver grafts from donors with evidence of past HBV infection is quite limited, some data have been collected regarding the feasibility of transplanting a liver graft from a hepatitis B surface antigen(HBs Ag) positive donor. The aim of the present work was to review the literature regarding liver transplants from HBs Ag-positive donors. A total of 17 studies were identified by a search in Medline. To date, HBs Ag positive grafts have preferentially been allocated to HBs Ag positive recipients. The large majority of these patients continue to be HBs Ag positive despite the use of immunoglobulin, and infection prevention can only be guaranteed by using antiviral prophylaxis. Although serological persistence is evident, no significant HBV-related disease has been observed, except in patients coinfected with delta virus. Consistently less data are available for HBs Ag negative recipients, although they are mostly promising. HBs Agpositive grafts could be an additional organ source for liver transplantation, provided that the risk of reinfection/reactivation is properly prevented.
基金supported by the National Natural Science Foundation of China,No.81372041(to DW),and No.81801220(to MGZ)
文摘We previously demonstrated that overexpression of tropomyosin receptor kinase A(TrkA)promotes the survival and Schwann celllike differentiation of bone marrow stromal stem cells in nerve grafts,thereby enhancing the regeneration and functional recovery of the peripheral nerve.In the present study,we investigated the molecular mechanisms underlying the neuroprotective effects of TrkA in bone marrow stromal stem cells seeded into nerve grafts.Bone marrow stromal stem cells from Sprague-Dawley rats were infected with recombinant lentivirus vector expressing rat TrkA,TrkA-shRNA or the respective control.The cells were then seeded into allogeneic rat acellular nerve allografts for bridging a 1-cm right sciatic nerve defect.Then,8 weeks after surgery,hematoxylin and eosin staining showed that compared with the control groups,the cells and fibers in the TrkA overexpressing group were more densely and uniformly arranged,whereas they were relatively sparse and arranged in a disordered manner in the TrkA-shRNA group.Western blot assay showed that compared with the control groups,the TrkA overexpressing group had higher expression of the myelin marker,myelin basic protein and the axonal marker neurofilament 200.The TrkA overexpressing group also had higher levels of various signaling molecules,including TrkA,pTrkA(Tyr490),extracellular signal-regulated kinases 1/2(Erkl/2),pErk1/2(Thr202/Tyr204),and the anti-apoptotic proteins Bcl-2 and Bcl-xL.In contrast,these proteins were downregulated,while the pro-apoptotic factors Bax and Bad were upregulated,in the TrkA-shRNA group.The levels of the TrkA effectors Akt and pAkt(Ser473)were not different among the groups.These results suggest that TrkA enhances the survival and regenerative capacity of bone marrow stromal stem cells through upregulation of the Erk/Bcl-2 pathway.All procedures were approved by the Animal Ethical and Welfare Committee of Shenzhen University,China in December 2014(approval No.AEWC-2014-001219).
文摘AIM: To evaluate the dual-graft living donor liver transplantation (LDLT) with ultrasonography, with special emphasis on the postoperative complications. METHODS: From January 2002 to August 2007, 110 adult-to-adult LDLTs were performed in West China Hos- pital of Sichuan University. Among them, dual-graft implantations were performed in six patients. Sonographic findings of the patients were retrospectively reviewed. RESULTS: All the six recipients survived the dual-graft adult-to-adult LDLT surgery. All had pleural effusion. Four patients had episodes of postoperative abdominal complications, including fluid collection between the grafts in three patients, intrahepatic biliary dilatation in two, hepatofugal portal flow of the left lobe in two, and atrophy of the left lobe in one. CONCLUSION: Although dual-graft LDLT takes more efforts and is technically complicated, it is safely feasible. Postoperative sonographic monitoring of the recipient is important.
文摘Liver transplantation(LT) is one of the most effective treatments for end-stage liver disease caused by related risk factors when liver resection is contraindicated. Additionally,despite the decrease in the prevalence of hepatitis B virus(HBV) over the past two decades,the absolute number of HBs Ag-positive people has increased,leading to an increase in HBV-related liver cirrhosis and hepatocellular carcinoma. Consequently,a large demand exists for LT. While the wait time for patients on the donor list is,to some degree,shorter due to the development of living donor liver transplantation(LDLT),there is still a shortage of liver grafts. Furthermore,recipients often suffer from emergent conditions,such as liver dysfunction or even hepatic encephalopathy,which can lead to a limited choice in grafts. To expand the pool of available liver grafts,one option is the use of organs that were previously considered "unusable" by many,which are often labeled "marginal" organs. Many previous studies have reported on the possibilities of using marginal grafts in orthotopic LT; however,there is still a lack of discussion on this topic,especially regarding the feasibility of using marginal grafts in LDLT. Therefore,the present review aimed to summarize the feasibility of using marginal liver grafts for LDLT and discuss the possibility of expanding the application of these grafts.
基金Supported by the National Natural Science Foundation,No.81470896the Project of Development and Innovation Team of Ministry of Education,No.IRT_16R57
文摘AIM To compare the effect of University of Wisconsin(UW) solution with or without metformin, an AMP-activated protein kinase(AMPK) activator, for preserving standard and marginal liver grafts of young and aged rats ex vivo by hypothermic machine perfusion(HMP).METHODS Eighteen young(4 mo old) and 18 aged(17 mo old)healthy male SD rats were selected and randomly divided into three groups: control group, UW solution perfusion group(UWP), and UW solution with metformin perfusion group(MUWP). Aspartate aminotransferase(AST), alanine aminotransferase(ALT), lactate dehydrogenase(LDH), interleukin-18(IL-18), and tumor necrosis factor-alpha(TNF-α) in the perfused liquid were tested. The expression levels of AMPK and endothelial nitric oxide synthase(e NOS) in liver sinusoidal endothelial cells were also examined.Additionally, microscopic evaluation of the harvested perfused liver tissue samples was done. RESULTS AST, ALT, LDH, IL-18 and TNF-α levels in the young and aged liver-perfused liquid were, respectively,significantly lower in the MUWP group than in the UWP group(P < 0.05), but no significant differences were found between the young and aged MUWP groups.Metformin increased the expression of AMPK and e NOS protein levels, and promoted the extracellular release of nitric oxide through activation of the AMPK-e NOS mediated pathway. Histological examination revealed that in the MUWP group, the extent of liver cells and tissue damage was significantly reduced compared with the UWP group.CONCLUSION The addition of metformin to the UW preservative solution for ex vivo HMP can reduce rat liver injury during cold ischemia, with significant protective effects on livers, especially of aged rats.
基金the Innovation and Technology Fund-The Hong Kong Research Institute of Textiles and Apparel (ITF-HKRITA, PRP/059/19TI)the Department General Research Fund, the Hong Kong Polytechnic University (G-UAHB) for supporting this study。
文摘This study reviews the state of the art in structural design and the corresponding mechanical behaviours of composite vascular grafts. We critically analyse surface and matrix designs composed of layered, embedded, and hybrid structures along the radial and longitudinal directions;materials and manufacturing techniques, such as tissue engineering and the use of textiles or their combinations;and the corresponding mechanical behaviours of composite vascular grafts in terms of their physical–mechanical properties, especially their stress–strain relationships and elastic recovery. The role of computational studies is discussed with respect to optimizing the geometrics designs and the corresponding mechanical behaviours to satisfy specialized applications, such as those for the aorta and its subparts. Natural and synthetic endothelial materials yield improvements in the mechanical and biological compliance of composite graft surfaces with host arteries. Moreover,the diameter, wall thickness, stiffness, compliance, tensile strength, elasticity, and burst strength of the graft matrix are determined depending on the application and the patient. For composite vascular grafts, hybrid architectures are recommended featuring multiple layers, dimensions, and materials to achieve the desired optimal flexibility and function for complying with user-specific requirements. Rapidly emerging artificial intelligence and big data techniques for diagnostics and the threedimensional(3D) manufacturing of vascular grafts will likely yield highly compliant, subject-specific, long-lasting, and economical vascular grafts in the near-future.
基金Supported by Saving Sight in Grampian,Development Trust of University of Aberdeen,United KingdomAction Medical Research United Kingdom(grant SP4328)Link?ping University,Sweden
文摘Corneal transplantation is the most common surgical procedure amongst solid organ transplants with a high survival rate of 86% at 1-year post-grafting. This high success rate has been attributed to the immune privilege of the eye. However, mechanisms originally thought to promote immune privilege, such as the lack of antigen presenting cells and vessels in the cornea, are challenged by recent studies. Nevertheless, the immunological and physiological features of the cornea promoting a relatively weak alloimmune response is likely responsible for the high survival rate in "low-risk" settings. Furthermore, although corneal graft survival in "lowrisk" recipients is favourable, the prognosis in "high-risk" recipients for corneal graft is poor. In "high-risk" grafts, the process of indirect allorecognition is accelerated by the enhanced innate and adaptive immune responses due to pre-existing inflammation and neovascularization of the host bed. This leads to the irreversible rejection of the allograft and ultimately graft failure. Many therapeutic measures are being tested in pre-clinical and clinical studies to counter the immunological challenge of "high-risk" recipients. Despite the prevailing dogma, recent data suggest that tissue matching together with use of systemic immunosuppression may increase the likelihood of graft acceptance in "high-risk" recipients. However, immunosuppressive drugs are accompanied with intolerance/side effects and toxicity, and therefore, novel cell-based therapies are in development which target host immune cells and restore immune homeostasis without significant side effect of treatment. In addition, developments in regenerative medicinemay be able to solve both important short comings of allotransplantation:(1) graft rejection and ultimate graft failure; and(2) the lack of suitable donor corneas. The advances in technology and research indicate that wider therapeutic choices for patients may be available to address the worldwide problem of corneal blindness in both "low-risk" and "high-risk" hosts.
文摘Coronary artery bypass grafting surgery is increasingly being carried out on patients with multi-vessel coronary artery disease,but the best grafting candidate for non-left anterior descending coronary arteries is unclear.This research sought to systematically compare the efficacies and safeties of coronary bypass with radial artery and other available grafts.A systematic literature retrieval was performed for all clinical trials comparing the outcomes of coronary artery bypass surgery with radial artery and other grafts in PubMed,EMBASE,and the Cochrane Library.Seven eligible clinical studies,comparing radial artery and great saphenous vein grafts,were found between 1966 and 2010:one prospective non-randomized and six prospective randomized trials.The pooling analysis obtained a relative risk of 0.507 (P<0.05) of graft occlusion in radial arteries compared with great saphenous veins.There was a significantly lower infection rate in arms (i.e.,harvest sites for radial arteries) relative to legs (harvest sites for veins),with a pooled relative risk of 0.140 (P<0.05).From the reports on mortality after follow-up ranging from one year to six years,there was no significant difference in mortality between the two graft types (P=0.927).In addition,four cohort controlled trials for radial and right internal thoracic artery grafts were included.The radial graft was associated with less cardiac related events relative to the right internal thoracic artery graft (P=0.014),but with comparable mortality and comparable rates of repeat percutaneous transluminal coronary angioplasty.Subjects with radial arteries seemed to have a lower occlusion rate and a lower graft harvest site infection rate than those with great saphenous veins.Moreover there were fewer cardiac related events with radial arteries relative to the right internal thoracic artery grafts.More studies are needed to confirm these findings concerning the favorable outcomes of coronary artery bypass grafting with radial arteries on long-term patency and mortality.
基金the grant from Education Committee of Hebei Province, No.2002234
文摘BACKGROUND: The source of nerve allograft enriches. We may choose expediently nerve allograft to repair injured nerve and the structure of choice nerve homology or similar with the injured nerve, but the immunological rejection limits the clinical application of nerve allograft. The ideal substitute of autograft never is researching. OBJECTIVE: In this experiment, Triton X-100 was used to extract the Schwann cells and myelin sheaths of allograft nerve and obtain the inartificial and eliminated antigenicity nerve-transplanter (nerve grafts). DESIGN: Controlled experiment. SETTING: Department of Hand Surgery, the Third Affiliated Hospital of Hebei Medical University; Second Department of Orthopedics, Fourth Center Hospital of Tianjin. MATERIALS: Thirty health New Zealand big ear white rabbit, of either sex (gender), weighing 2000-3000 g, were provided by the Center of Experimental Animal of Hebei Medical University. TritonX-100 was offered by SIGMA Company. METHODS: The experiment was carried out at the Central Laboratory of the Third Affiliated Hospital of Hebei Medical University from December 2003 to December 2004. Sixty pieces of sciatic nerves, 10-mm-long nerve segment, which were taken from 30 rabbits, were incised. They were randomly divided into chemical extraction group (n =50) and control group (n =10). In the chemical extraction groups, the nerves were put into 3% Triton X-100 solution. They were treated with Triton X-100 for 12 hours, 24 hours, 48 hours, 96 hours and 1 week, respectively. They were examined in every period. The control groups did not treated with anything. ① Respectively two segments of nerve by 2 mm length were taken from each nerve in the every periods. ② The laminin immunohistochemical stained sections were performed with image acquisition and analyzed with multicolor pathological image analysis system. Measured the laminin antibody reaction part of each section and computed laminin average gray degrees of the unit area. All dates were analyzed by SPSS 10.0 software. MAIN OUTCOME MEASURES: ① General observation and histological observation in two groups; ② Compared with laminin average gray degrees of the unit area in each section. RESULTS: ① General observation: In the control groups, fresh nerve was polish, rigidity and elasticity. After the nerves were chemical extracted, the floccules was seen at two ends and around of the nerves. The nerves being extraction presented ivory and lackluster. Its diameter and length compared reduced, tenderness and tenacity with the fresh nerve. Observed by light microscope, Schwann cells, myelin sheaths and basement membrane distribute uniformly in control groups. After the nerves were extracted, Schwann cells and myelin sheaths disappeared. Basement membrane presented barrier array in longitudinal sections. Between the membranes was the basement membrane tube. Observed with scanning electron microscope, the basement membrane tubes composed by collagen fibers were remained and collagen fibers maintained their former position, form and structure. Further, the structure of membrane was seen in the tubes. It was Schwann cells basement membrane. ② In chemical extraction groups, laminin average gray degrees of the unit area were 140.1±3.41 (12 hours), 142.1±3.14 (24 hours), 142.1±3.14 (48 hours), 140.4±4.03 (96 hours), 141.7±2.62 (1 week). In the control groups, laminin average gray degree of the unit area was 142.7±7.24. There were not significant differences among the groups (P > 0.05). CONCLUSION: The method of chemical extraction by using of Triton X-100 may be an ideal measure for preparing tissue-engineered nerve-transplanter and reserved the live of laminin in the basement membrane.
