Stent fracture after transjugular intrahepatic portosystemic shunt placement using the bare metal stent/stent-graft combination technique

BACKGROUND A transjugular intrahepatic portosystemic shunt(TIPS)is widely placed to treat portal hypertension.Because the Viatorr®stent(W.L.Gore and Associates,Flagstaff,AZ,United States)is not available in all hospitals in China,the bare metal stent(BMS)/stent-graft combination technique is still popular for TIPS construction.Stent fracture is a complication after TIPS placement using this technique,with limited available literature focusing on it.AIM To assess the incidence of stent fracture after TIPS placement using the BMS/stent-graft combination technique and to identify the risk factors for stent fracture.We proposed technique modifications to improve the clinical results of TIPS placement with the BMS/stent-graft combination technique.METHODS We retrospectively analyzed the computed tomography(CT)data of all patients with portal hypertension who underwent the TIPS procedure between June 2011 and December 2021 in a single center.Patients implanted with the BMS/stent graft and had follow-up imaging data available were included.We identified patients with stent fracture and analyzed their characteristics.Multivariable logistic regression was applied to identify the potential predictors of stent fracture.RESULTS Of the 68 included patients,stent fracture occurred in seven(10.3%)patients.Based on CT images,the stent fractures were categorized into three types.Our study consisted of four(57.1%)type I fractures,one(14.3%)type II fracture,one(14.3%)type IIIa fracture,and one(14.3%)type IIIb fracture.After adjusting for covariates,multivariable logistic regression revealed that the risk factors for stent fracture were the implantation of a greater number of stents[adjusted odds ratio(aOR)=22.2,95%confidence interval(CI):1.2-415.4,P=0.038]and a larger proximal sagittal stent bending angle(aOR=1.1,95%CI:1.0-1.3,P=0.020).CONCLUSION Stent fracture occurred in approximately 10%of patients with portal hypertension who underwent TIPS with the BMS/stent-graft combination technique.The number of implanted stents and stent bending angle at the inferior vena cava end were predictors of stent fracture,which suggests that the incidence of stent fracture could potentially be reduced by procedural modifications.

Is concomitant radiotherapy necessary with gemcitabinebased chemotherapy in pancreatic cancer?

AIM:To evaluate the efficacy and safety of gemcitabine(GEM)plus radiotherapy compared with GEM alone for pancreatic cancer(PC).METHODS:A systematic search for eligible studies comparing gemcitabine plus radiotherapy with gemcitabine alone for PC was performed using MEDLINE,EMBASE,and the Cochrane Library.A quality assessment was performed in each study.Meta-analyses were performed to study the pooled effects of relative risk with 95%confidence interval(CI).RESULTS:A total of 336 participants from four original studies were included.Gemcitabine plus radiotherapy resulted in comparable overall survival(HR=0.84,95%CI:0.53-1.34,P=0.48)and progress freesurvival(HR=0.99,95%CI:0.97-1.01,P=0.36)to gemcitabine alone.Moreover,concomitant radiotherapy was associated with a significantly higher incidence of severe(grade 3 or greater)toxicities,mainly anemia,leukocytopenia,thrombocytopenia,anorexia,nausea/vomiting,and asthenia/fatigue.CONCLUSION:Radiotherapy is not beneficial with gemcitabine-based chemotherapy for PC.Further exploration for better radiotherapy approaches and therapeutic regimens for the treatment of PC is warranted.

Developing a diagnostic model for predicting prostate cancer: a retrospective study based on Chinese multicenter clinical data

The overdiagnosis of prostate cancer(PCa)caused by nonspecific elevation serum prostate-specific antigen(PSA)and the overtreatment of indolent PCa have become a global problem that needs to be solved urgently.We aimed to construct a prediction model and provide a risk stratification system to reduce unnecessary biopsies.In this retrospective study,clinical data of 1807 patients from three Chinese hospitals were used.The final model was built using stepwise logistic regression analysis.The apparent performance of the model was assessed by receiver operating characteristic curves,calibration plots,and decision curve analysis.Finally,a risk stratification system of clinically significant prostate cancer(csPCa)was created,and diagnosis-free survival analyses were performed.Following multivariable screening and evaluation of the diagnostic performances,a final diagnostic model comprised of the PSA density and Prostate Imaging-Reporting and Data System(PI-RADS)score was established.Model validation in the development cohort and two external cohorts showed excellent discrimination and calibration.Finally,we created a risk stratification system using risk thresholds of 0.05 and 0.60 as the cut-off values.The follow-up results indicated that the diagnosis-free survival rate for csPCa at 12 months and 24 months postoperatively was 99.7%and 99.4%,respectively,for patients with a risk threshold below O.05 after the initial negative prostate biopsy,which was significantly better than patients with higher risk.Our diagnostic model and risk stratification system can achieve a personalized risk calculation of csPCa.It provides a standardized tool for Chinese patients and physicians when considering thenecessity of prostatebiopsy.

High-strength mineralized collagen artificial bone

Mineralized collagen （MC） is a biomimetic material that mimics natural bone matrix in terms of both chemical composition and microstructure. The biomimetic MC possesses good biocompatibility and osteogenic activity, and is capable of guiding bone regeneration as being used for bone defect repair. However, mechanical strength of existing MC artificial bone is too low to provide effective support at human load-bearing sites, so it can only be used for the repair at non-load-bearing sites, such as bone defect filling, bone graft augmentation, and so on. In the present study, a high strength MC artificial bone material was developed by using collagen as the template for the biomimetic mineralization of the calcium phosphate, and then followed by a cold compression molding process with a certain pressure. The appearance and density of the dense MC were similar to those of natural cortical bone, and the phase composition was in conformity with that of animal＇s cortical bone demonstrated by XRD. Mechanical properties were tested and results showed that the compressive strength was comparable to human cortical bone, while the compressive modulus was as low as human cancellous bone. Such high strength was able to provide effective mechanical support for bone defect repair at human load-bearing sites, and the low compressive modulus can help avoid stress shielding in the application of bone regeneration. Both in vitro cell experiments and in v/vo implantation assay demonstrated good biocompatibility of the material, and in v/vo stability evaluation indicated that this high-strength MC artificial bone could provide long-term effective mechanical support at human load- bearing sites.

Strength and fatigue properties of three-step sintered dense nanocrystal hydroxyapatite bioceramics

Dense hydroxyapatite （HA） ceramic is a promising material for hard tissue repair due to its unique physical properties and biologic properties. However, the brittleness and low compressive strength of traditional HA ceramics limited their applications, because previous sintering methods produced HA ceramics with crystal sizes greater than nanometer range. In this study, nano-sized HA powder was employed to fabricate dense nanocrystal HA ceramic by high pressure molding, and followed by a three-step sintering process. The phase composition, microstructure, crystal dimension and crystal shape of the sintered ceramic were examined by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. Mechanical properties of the HA ceramic were tested, and cytocompatibility was evaluated. The phase of the sintered ceramic was pure HA, and the crystal size was about 200 nm. The compressive strength and elastic modulus of the HA ceramic were comparable to human cortical bone, especially the good fatigue strength overcame brittleness of traditional sintered HA ceramics. Cell attachment experiment also demonstrated that the ceramics had a good cytocompatibility.

C-arm-based flat-panel detector cone-beam computed tomography venography in the diagnosis of iliac vein compression syndrome

Background:C-arm-based flat-panel detector cone-beam computed tomography(CBCT)venography has never been used in the management of iliac vein compression syndrome(IVCS).This study aimed to determine the technical feasibility and safety of CBCT venography in the diagnosis of IVCS compared with conventional venography(CV).Methods:Twenty patients with clinical manifestations of lower extremity venous insufficiency were prospectively enrolled between May 2018 and December 2018.Each patient underwent both CV and CBCT venography.The feasibility and safety of CBCT venography were assessed by technical success rate and complication rate.The relationships between the clinical indexes and the results of CBCT venography and CV were analyzed with correlation analysis.The consistency of the diagnosis of IVCS using each modality was analyzed by the kappa test.Results:The technical success rate was 100%for CBCT venography and for CV,without any complications.Compared with CV,CBCT venography was able to show more details of adjacent tissues which might be helpful for making etiological diagnosis.The stenosis rate under CBCT venography had excellent consistency with that under CV(kappa=0.78,Chi-square test).The stenosis rate under CBCT venography was positively correlated with the presence of collateral veins(odds ratio 1.12,95%confidence interval:[1.00,1.26],P=0.049),while the stenosis rate under CV was not.Unexpectedly,only one patient had a venous pressure gradient of more than 2 mmHg(1 mmHg=0.133 kPa).Conclusions:For the diagnosis of IVCS,C-arm-based CBCT venography was technically feasible,with good safety.The presence of collateral veins on CBCT was clinically significant.A C-arm fluoroscopy-based technique that combines CV and CBCT might be a promising protocol for the management of IVCS during a single session.

Hybrid surgery for symptomatic chronic near-total or total occlusion of the internal carotid artery

Stroke is the second leading cause of death globally and accounts for an estimated 5.5 million deaths each year worldwide.[1]Revascularization of the carotid artery is one of the key procedures to reduce the incidence of stroke.Chronic total occlusion(TO)and near-total occlusion(NO)of the carotid artery are rare.Treatment for TO and NO is controversial with potential complications,including periprocedural stroke,intracranial hemorrhage,and carotid-cavernous fistula(CCF).[2]There have been attempts to implement carotid artery endarterectomy(CEA)and endovascular treatment,but the success rates were far from satisfactory.For patients with TO,the success rate of revascularization is around 40%and 60%,respectively,for CEA and endovascular technique.[3]For patients with NO,the morbidity and mortality rates are 3%and 9%,respectively.

Transcription Factor MAFA Regulates Mechanical Sensation by Modulating Piezo2 Expression

Dear Editor,Essential for survival,mechanical sensation is detected and transmited to the spinal cord by primary sensory afferents and their cell bodies located in the dorsal root ganglia(DRG).Multiple types of mechanically sensitive DRG neurons have been identified that mediate various mechanosensation modalities(e.g.non-painful versus painful).