Autografting is the gold standard for surgical repair of nerve defects>5 mm in length;however,autografting is associated with potential complications at the nerve donor site.As an alternative,nerve guidance conduit...Autografting is the gold standard for surgical repair of nerve defects>5 mm in length;however,autografting is associated with potential complications at the nerve donor site.As an alternative,nerve guidance conduits may be used.The ideal conduit should be flexible,resistant to kinks and lumen collapse,and provide physical cues to guide nerve regeneration.We designed a novel flexible conduit using electrospinning technology to create fibers on the innermost surface of the nerve guidance conduit and employed melt spinning to align them.Subsequently,we prepared disordered electrospun fibers outside the aligned fibers and helical melt-spun fibers on the outer wall of the electrospun fiber lumen.The presence of aligned fibers on the inner surface can promote the extension of nerve cells along the fibers.The helical melt-spun fibers on the outer surface can enhance resistance to kinking and compression and provide stability.Our novel conduit promoted nerve regeneration and functional recovery in a rat sciatic nerve defect model,suggesting that it has potential for clinical use in human nerve injuries.展开更多
Peripheral nerve injuries induce a severe motor and sensory deficit. Since the availability of autologous nerve transplants for nerve repair is very limited, alternative treatment strategies are sought, including the ...Peripheral nerve injuries induce a severe motor and sensory deficit. Since the availability of autologous nerve transplants for nerve repair is very limited, alternative treatment strategies are sought, including the use of tubular nerve guidance conduits(tNGCs). However, the use of tNGCs results in poor functional recovery and central necrosis of the regenerating tissue, which limits their application to short nerve lesion defects(typically shorter than 3 cm). Given the importance of vascularization in nerve regeneration, we hypothesized that enabling the growth of blood vessels from the surrounding tissue into the regenerating nerve within the tNGC would help eliminate necrotic processes and lead to improved regeneration. In this study, we reported the application of macroscopic holes into the tubular walls of silk-based tNGCs and compared the various features of these improved silk^(+) tNGCs with the tubes without holes(silk^(–) tNGCs) and autologous nerve transplants in an 8-mm sciatic nerve defect in rats. Using a combination of micro-computed tomography and histological analyses, we were able to prove that the use of silk^(+) tNGCs induced the growth of blood vessels from the adjacent tissue to the intraluminal neovascular formation. A significantly higher number of blood vessels in the silk^(+) group was found compared with autologous nerve transplants and silk^(–), accompanied by improved axon regeneration at the distal coaptation point compared with the silk^(–) tNGCs at 7 weeks postoperatively. In the 15-mm(critical size) sciatic nerve defect model, we again observed a distinct ingrowth of blood vessels through the tubular walls of silk^(+) tNGCs, but without improved functional recovery at 12 weeks postoperatively. Our data proves that macroporous tNGCs increase the vascular supply of regenerating nerves and facilitate improved axonal regeneration in a short-defect model but not in a critical-size defect model. This study suggests that further optimization of the macroscopic holes silk^(+) tNGC approach containing macroscopic holes might result in improved grafting technology suitable for future clinical use.展开更多
BACKGROUND Aorto-hepatic conduits(AHCs)are an effective revascularization method for liver allografts when the native hepatic artery is unusable.Various studies have confirmed that outcomes with AHCs are inferior to t...BACKGROUND Aorto-hepatic conduits(AHCs)are an effective revascularization method for liver allografts when the native hepatic artery is unusable.Various studies have confirmed that outcomes with AHCs are inferior to those with native hepatic artery inflow.AIM To investigate the published evidence on the outcomes according to different inflow site for AHCs.METHODS A systematic search was conducted for studies reporting on AHCs in liver transplantation over the last 10 years(January 2014 onwards).Two independent reviewers selected articles,assessed quality,and evaluated bias in the included systematic reviews.The methodological quality of the included studies was assessed using the Newcastle-Ottawa Scale.The protocol was registered with PROSPERO(CRD42024545810).Review was conducted using the Preferred Reporting Items for Systematic Review and Meta-Analysis statement standards.RESULTS Fourteen studies identified a total of 32486 deceased donor liver transplants,of which 1136(3.5%)required AHCs.The most frequent indications for AHC use included poor arterial flow,intimal dissections,and hepatic artery thrombosis.Among all AHCs,207(18.2%)were supra-coeliac(SC)AHCs,738(65.0%)infrarenal(IR)AHCs,25(2.2%)iliac artery conduits,and 166(14.6%)had unspecified origins.Pooled analysis revealed comparable demographic characteristics.The median follow-up duration ranged from 18 to 52 months.There were no significant differences in early occlusions of AHCs[odds ratio(OR)=0.94(0.48,1.84);P=0.86],late occlusions of AHCs[OR=0.46(0.16,1.32);P=0.15],early allograft dysfunction[OR=0.82(0.46,1.47);P=0.51],biliary complications[OR=1.10(0.69,1.76);P=0.68],post-transplant renal replacement therapy(RRT)requirement[OR=1.12(0.72,1.72);P=0.62],and major surgical complications(Clavien-Dindo>3b)[OR=1.06(0.70,1.61);P=0.79].The median duration for graft occlusion was approximately 142 days,ranging from 13 to 3313 days.One-year graft and patient survival rates for SC conduits were 77%to 81.1%and 80%to 85.1%,respectively.For IR conduits,one-year graft and patient survival rates were 66%to 79.1%and 73%to 88.3%,respectively.Five-year graft and patient survival rates for SC conduits were 53.9%to 67%and 67.8%to 74%,respectively.For IR conduits,five-year graft and patient survival rates were 50%to 56%and 56%to 64.9%,respectively.CONCLUSION Considering these findings,there is no significant difference in early and late outcomes between SC and IR AHCs,although there is a discernible tendency towards higher late occlusion rates in the IR group.展开更多
BACKGROUND Type 2 diabetes(T2D)remission has been widely reported after bariatric surgery,but rarely reported after esophagectomy.AIM To explore the incidence and predictors of T2D remission 1 year after esophagectomy...BACKGROUND Type 2 diabetes(T2D)remission has been widely reported after bariatric surgery,but rarely reported after esophagectomy.AIM To explore the incidence and predictors of T2D remission 1 year after esophagectomy with gastric conduit reconstruction.METHODS In this prospective study,consecutive patients from 2 tertiary hospitals who had esophageal cancer and T2D and underwent esophagectomy with gastric conduit reconstruction were studied preoperatively and at 3 months,6 months,and 12 months postoperatively.Remission of T2D is defined as glycated hemoglobin(HbA1c)values below 6.5%without glucose-lowering medications.Related clinical information were recorded and analyzed.RESULTS A total of 187 patients were included.Of these patients,24(12.8%)discontinued antidiabetic drugs and maintained HbA1c values below 6.5%1 year after surgery.At baseline,patients with T2D remission were younger(63.0±5.2 years vs 67.0±6.1 years,P=0.002),had higher body mass index values(body weight 68.6±11.1 kg vs 61.2±9.3 kg,P=0.001;body mass index 25.5±2.4 kg/m2 vs 23.8±3 kg/m2,P=0.011),shorter duration of T2D(4.9±3.9 years vs 7.1±3.7 years,P=0.008)and higher preoperative HbA1c(8.5%±1.7%vs 7.7%±1.3%,P=0.042).Multivariate logistic regression analysis showed that younger age and greater body weight were independent predictors of T2D remission after surgery.CONCLUSION This study reveals a significant incidence of T2D remission after esophagectomy with gastric conduit reconstruction,and remission is more frequent in patients with younger age and greater body weight.展开更多
The flow field characteristics of the conduit-matrix system(CMS)have consistently been a primary area of interest to researchers.However,under the long-term influence of water flow,the hydraulic conductivity of the ma...The flow field characteristics of the conduit-matrix system(CMS)have consistently been a primary area of interest to researchers.However,under the long-term influence of water flow,the hydraulic conductivity of the matrix surrounding the conduit often deforms differentially along the conduit axis,resulting in the development of a conduit-multilayer matrix system(CMMS).This renders conventional models inadequate in accurately describing the flow field characteristics of CMMS.In this study,a semi-analytical model with second-order accuracy is developed to investigate the velocity profile characteristics of CMMS by coupling the Navier-Stokes(N–S)equations in the conduit and the Darcy-Brinkman(D-B)equation in the multilayer matrices.In this model,the interface between the conduit and the matrix satisfies the velocity continuity and stress jumping condition.In contrast,different matrix interfaces require both velocity and stress to be equal.The model's validity is verified through Lattice Boltzmann Method(LBM)simulation,COMSOL simulation,and experimental data under different conduit apertures,matrix region numbers,and matrix permeability characteristics.Moreover,the current model predicts discharges with higher accuracy than the Hagen-Poiseuille law and Darcy's law(the maximum error between the present model and the test is 7.24%).Furthermore,the existing Poiseuille's law,conduit-matrix model,and conduit-matrix1-matrix2 model are all special cases of the current semi-analytical model,thereby indicating its broader applicability.Sensitivity results reveal that the flow velocities in the surrounding matrix and the conduit regions also increase when the permeability of the matrix in proximity to the conduit increases.Additionally,as the stress jumping coefficient at the interface approaches zero,the transition from free flow to seepage becomes smoother.展开更多
Traumatic peripheral nerve injuries are a major contributor to long-term disability,accounting for nearly half of all peripheral nervous system disorders.Although autologous nerve grafting remains the clinical gold st...Traumatic peripheral nerve injuries are a major contributor to long-term disability,accounting for nearly half of all peripheral nervous system disorders.Although autologous nerve grafting remains the clinical gold standard,it is limited by donor-site morbidity and often fails to achieve full functional recovery.Biodegradable collagen conduits have emerged as an appealing alternative,providing a scaffold for directed axonal growth without requiring graft harvest.We reported three cases of chronic nerve injuries(6-12 months post-trauma):two involving 2.0-3.5 cm ulnar nerve defects in the forearm and one with a 2.5 cm median nerve defect at the wrist.Under microscopic guidance,each defect was bridged with a tubular type I collagen conduit secured by epineurial sutures,followed by standardized physiotherapy and sensory reeducation.At 12-18 months of follow-up,all patients demonstrated near-complete sensory recovery—two-point discrimination and Semmes-Weinstein thresholds returned to≤6 mm—and motor function improved to Medical Research Council grades 4-5,restoring fine dexterity and grip strength.Patient-reported measures indicated marked reductions in neuropathic pain and paresthesia.No conduit-related adverse events or neuroma formation were observed.This case series highlights the potential of collagen-based conduits to promote robust axonal regeneration and functional restoration even in delayed presentations.By eliminating donor-site morbidity and simplifying the reconstructive procedure,conduit-assisted repair offers a less invasive,reproducible alternative to autologous grafts for both acute and chronic peripheral nerve injuries.展开更多
基金supported by the National Natural Science Foundation of China,No.82202718the Natural Science Foundation of Beijing,No.L212050the China Postdoctoral Science Foundation,Nos.2019M664007,2021T140793(all to ZL)。
文摘Autografting is the gold standard for surgical repair of nerve defects>5 mm in length;however,autografting is associated with potential complications at the nerve donor site.As an alternative,nerve guidance conduits may be used.The ideal conduit should be flexible,resistant to kinks and lumen collapse,and provide physical cues to guide nerve regeneration.We designed a novel flexible conduit using electrospinning technology to create fibers on the innermost surface of the nerve guidance conduit and employed melt spinning to align them.Subsequently,we prepared disordered electrospun fibers outside the aligned fibers and helical melt-spun fibers on the outer wall of the electrospun fiber lumen.The presence of aligned fibers on the inner surface can promote the extension of nerve cells along the fibers.The helical melt-spun fibers on the outer surface can enhance resistance to kinking and compression and provide stability.Our novel conduit promoted nerve regeneration and functional recovery in a rat sciatic nerve defect model,suggesting that it has potential for clinical use in human nerve injuries.
基金supported by the Lorenz B?hler Fonds,#2/19 (obtained by the Neuroregeneration Group,Ludwig Boltzmann Institute for Traumatology)the City of Vienna project ImmunTissue,MA23#30-11 (obtained by the Department Life Science Engineering,University of Applied Sciences Technikum Wien)。
文摘Peripheral nerve injuries induce a severe motor and sensory deficit. Since the availability of autologous nerve transplants for nerve repair is very limited, alternative treatment strategies are sought, including the use of tubular nerve guidance conduits(tNGCs). However, the use of tNGCs results in poor functional recovery and central necrosis of the regenerating tissue, which limits their application to short nerve lesion defects(typically shorter than 3 cm). Given the importance of vascularization in nerve regeneration, we hypothesized that enabling the growth of blood vessels from the surrounding tissue into the regenerating nerve within the tNGC would help eliminate necrotic processes and lead to improved regeneration. In this study, we reported the application of macroscopic holes into the tubular walls of silk-based tNGCs and compared the various features of these improved silk^(+) tNGCs with the tubes without holes(silk^(–) tNGCs) and autologous nerve transplants in an 8-mm sciatic nerve defect in rats. Using a combination of micro-computed tomography and histological analyses, we were able to prove that the use of silk^(+) tNGCs induced the growth of blood vessels from the adjacent tissue to the intraluminal neovascular formation. A significantly higher number of blood vessels in the silk^(+) group was found compared with autologous nerve transplants and silk^(–), accompanied by improved axon regeneration at the distal coaptation point compared with the silk^(–) tNGCs at 7 weeks postoperatively. In the 15-mm(critical size) sciatic nerve defect model, we again observed a distinct ingrowth of blood vessels through the tubular walls of silk^(+) tNGCs, but without improved functional recovery at 12 weeks postoperatively. Our data proves that macroporous tNGCs increase the vascular supply of regenerating nerves and facilitate improved axonal regeneration in a short-defect model but not in a critical-size defect model. This study suggests that further optimization of the macroscopic holes silk^(+) tNGC approach containing macroscopic holes might result in improved grafting technology suitable for future clinical use.
文摘BACKGROUND Aorto-hepatic conduits(AHCs)are an effective revascularization method for liver allografts when the native hepatic artery is unusable.Various studies have confirmed that outcomes with AHCs are inferior to those with native hepatic artery inflow.AIM To investigate the published evidence on the outcomes according to different inflow site for AHCs.METHODS A systematic search was conducted for studies reporting on AHCs in liver transplantation over the last 10 years(January 2014 onwards).Two independent reviewers selected articles,assessed quality,and evaluated bias in the included systematic reviews.The methodological quality of the included studies was assessed using the Newcastle-Ottawa Scale.The protocol was registered with PROSPERO(CRD42024545810).Review was conducted using the Preferred Reporting Items for Systematic Review and Meta-Analysis statement standards.RESULTS Fourteen studies identified a total of 32486 deceased donor liver transplants,of which 1136(3.5%)required AHCs.The most frequent indications for AHC use included poor arterial flow,intimal dissections,and hepatic artery thrombosis.Among all AHCs,207(18.2%)were supra-coeliac(SC)AHCs,738(65.0%)infrarenal(IR)AHCs,25(2.2%)iliac artery conduits,and 166(14.6%)had unspecified origins.Pooled analysis revealed comparable demographic characteristics.The median follow-up duration ranged from 18 to 52 months.There were no significant differences in early occlusions of AHCs[odds ratio(OR)=0.94(0.48,1.84);P=0.86],late occlusions of AHCs[OR=0.46(0.16,1.32);P=0.15],early allograft dysfunction[OR=0.82(0.46,1.47);P=0.51],biliary complications[OR=1.10(0.69,1.76);P=0.68],post-transplant renal replacement therapy(RRT)requirement[OR=1.12(0.72,1.72);P=0.62],and major surgical complications(Clavien-Dindo>3b)[OR=1.06(0.70,1.61);P=0.79].The median duration for graft occlusion was approximately 142 days,ranging from 13 to 3313 days.One-year graft and patient survival rates for SC conduits were 77%to 81.1%and 80%to 85.1%,respectively.For IR conduits,one-year graft and patient survival rates were 66%to 79.1%and 73%to 88.3%,respectively.Five-year graft and patient survival rates for SC conduits were 53.9%to 67%and 67.8%to 74%,respectively.For IR conduits,five-year graft and patient survival rates were 50%to 56%and 56%to 64.9%,respectively.CONCLUSION Considering these findings,there is no significant difference in early and late outcomes between SC and IR AHCs,although there is a discernible tendency towards higher late occlusion rates in the IR group.
基金Supported by the Technological innovation project of Shapingba District,No.2024111the Research Promotion Fund of Chongqing University Cancer Hospital,No.2023nlts008.
文摘BACKGROUND Type 2 diabetes(T2D)remission has been widely reported after bariatric surgery,but rarely reported after esophagectomy.AIM To explore the incidence and predictors of T2D remission 1 year after esophagectomy with gastric conduit reconstruction.METHODS In this prospective study,consecutive patients from 2 tertiary hospitals who had esophageal cancer and T2D and underwent esophagectomy with gastric conduit reconstruction were studied preoperatively and at 3 months,6 months,and 12 months postoperatively.Remission of T2D is defined as glycated hemoglobin(HbA1c)values below 6.5%without glucose-lowering medications.Related clinical information were recorded and analyzed.RESULTS A total of 187 patients were included.Of these patients,24(12.8%)discontinued antidiabetic drugs and maintained HbA1c values below 6.5%1 year after surgery.At baseline,patients with T2D remission were younger(63.0±5.2 years vs 67.0±6.1 years,P=0.002),had higher body mass index values(body weight 68.6±11.1 kg vs 61.2±9.3 kg,P=0.001;body mass index 25.5±2.4 kg/m2 vs 23.8±3 kg/m2,P=0.011),shorter duration of T2D(4.9±3.9 years vs 7.1±3.7 years,P=0.008)and higher preoperative HbA1c(8.5%±1.7%vs 7.7%±1.3%,P=0.042).Multivariate logistic regression analysis showed that younger age and greater body weight were independent predictors of T2D remission after surgery.CONCLUSION This study reveals a significant incidence of T2D remission after esophagectomy with gastric conduit reconstruction,and remission is more frequent in patients with younger age and greater body weight.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.52079068,52090081)the State Key Laboratory of Hydroscience and Engineering(Grant No.2021-KY-04).
文摘The flow field characteristics of the conduit-matrix system(CMS)have consistently been a primary area of interest to researchers.However,under the long-term influence of water flow,the hydraulic conductivity of the matrix surrounding the conduit often deforms differentially along the conduit axis,resulting in the development of a conduit-multilayer matrix system(CMMS).This renders conventional models inadequate in accurately describing the flow field characteristics of CMMS.In this study,a semi-analytical model with second-order accuracy is developed to investigate the velocity profile characteristics of CMMS by coupling the Navier-Stokes(N–S)equations in the conduit and the Darcy-Brinkman(D-B)equation in the multilayer matrices.In this model,the interface between the conduit and the matrix satisfies the velocity continuity and stress jumping condition.In contrast,different matrix interfaces require both velocity and stress to be equal.The model's validity is verified through Lattice Boltzmann Method(LBM)simulation,COMSOL simulation,and experimental data under different conduit apertures,matrix region numbers,and matrix permeability characteristics.Moreover,the current model predicts discharges with higher accuracy than the Hagen-Poiseuille law and Darcy's law(the maximum error between the present model and the test is 7.24%).Furthermore,the existing Poiseuille's law,conduit-matrix model,and conduit-matrix1-matrix2 model are all special cases of the current semi-analytical model,thereby indicating its broader applicability.Sensitivity results reveal that the flow velocities in the surrounding matrix and the conduit regions also increase when the permeability of the matrix in proximity to the conduit increases.Additionally,as the stress jumping coefficient at the interface approaches zero,the transition from free flow to seepage becomes smoother.
文摘Traumatic peripheral nerve injuries are a major contributor to long-term disability,accounting for nearly half of all peripheral nervous system disorders.Although autologous nerve grafting remains the clinical gold standard,it is limited by donor-site morbidity and often fails to achieve full functional recovery.Biodegradable collagen conduits have emerged as an appealing alternative,providing a scaffold for directed axonal growth without requiring graft harvest.We reported three cases of chronic nerve injuries(6-12 months post-trauma):two involving 2.0-3.5 cm ulnar nerve defects in the forearm and one with a 2.5 cm median nerve defect at the wrist.Under microscopic guidance,each defect was bridged with a tubular type I collagen conduit secured by epineurial sutures,followed by standardized physiotherapy and sensory reeducation.At 12-18 months of follow-up,all patients demonstrated near-complete sensory recovery—two-point discrimination and Semmes-Weinstein thresholds returned to≤6 mm—and motor function improved to Medical Research Council grades 4-5,restoring fine dexterity and grip strength.Patient-reported measures indicated marked reductions in neuropathic pain and paresthesia.No conduit-related adverse events or neuroma formation were observed.This case series highlights the potential of collagen-based conduits to promote robust axonal regeneration and functional restoration even in delayed presentations.By eliminating donor-site morbidity and simplifying the reconstructive procedure,conduit-assisted repair offers a less invasive,reproducible alternative to autologous grafts for both acute and chronic peripheral nerve injuries.
