Building Core Competence of Domestic-Made Mobile Phone

Chinese domestic mobile phone producerssnatched 30% market share in 2002.Some medias described it as“the firstyear of a reign”which showed the highexpectation from domestic mobile phone in-dustry. The inarguable fact behind the boom isthat most domestic mobile phone manufactur-ers put too more efforts on the brand and mar-ket strategy without any breakthrough in their

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.

Stent-grafts for the treatment of TIPS dysfunction:Fluency stent vs Wallgraft stent

AIM:To evaluate the clinical efficacy of an expanded polytetrafluoro-ethylene-covered Fluency stent compared with that of a polyethylene terephthalate-covered Wallgraft stent for the management of transjugular intrahepatic portosystemic shunt(TIPS)dysfunction.METHODS:A retrospective review of patients who underwent TIPS revision with stent-grafts between May 2007 and June 2011 was conducted.The patients were divided into two groups according to the stentgrafts implanted:the Fluency stent(Bard Incorporated,Karlsruhe,Germany)and the Wallgraft stent(Boston Scientific,Galway,Ireland).The primary patency rates were calculated and compared using the Kaplan-Meier method.RESULTS:A total of 73 patients were evaluated in this study:33 with Fluency stents and 40 with Wallgraft stents.The primary patency rates at 12 and 24 mo were 91% and 85%,respectively,in the Fluency stent group and 78% and 63%,respectively,in the Wallgraft stent group.The primary shunt patency rates after TIPS revision were significantly better with the Fluency stent than with the Wallgraft stent(P = 0.033).CONCLUSION:TIPS revision with the Fluency stent has higher medium-term patency rates than that with the Wallgraft stent.

Experimental and computational studies on the flow fields in aortic aneurysms associated with deployment of AAA stent-grafts

Pulsatile flow fields in rigid abdominal aortic aneurysm （AAA） models were investigated numerically, and the simulation results are found in good agreement with particle image velocimetry （PIV） measurements. There are one or more vortexes in the AAA bulge, and a fairly high wall shear stress exists at the distal end, and thus the AAA is in danger of rupture. Medical treatment consists of inserting a vascular stent-graft in the AAA, which would decrease the blood impact to the inner walls and reduce wall shear stress so that the rupture could be prevented. A new computational model, based on porous medium model, was developed and results are documented. Therapeutic effect of the stent-graft was verified numerically with the new model.

Stent-grafts placement for treatment of massive hemorrhage from ruptured hepatic artery after pancreaticoduodenectomy

AIM:To present a series of cases with life-threatening hemorrhage from ruptured hepatic artery pseudoaneurysm after pancreaticoduodenectomy(PD) treated with placement of stent-grafts.METHODS:Massive hemorrhage from ruptured hepatic artery pseudoaneurysm after PD in 9 patients(6 men,3 women) at the age of 23-75 years(mean 48 years),were treated with placement of percutaneous endovascular balloon-expandable coronary stent-grafts.All patients were not suitable for embolization because of a non-patent portal vein.One or more stent-grafts,ranging 3-6 mm in diameter and 16-55 mm in length,were placed to exclude ruptured pseudoaneurysm.Followup data,including clinical condition,liver function tests,and Doppler ultrasound examination,were recorded at the outpatient clinic.RESULTS:Immediate technical success was achieved in all the 9 patients.All stent-grafts were deployed in the intended position for immediate cessation of bleeding and preservation of satisfactory hepatic arterial blood flow.No significant procedure-related complications occurred.Recurrent bleeding occurred in 2 patients at 16 and 24 h,respectively,after placement of stent-grafts and treated with surgical revision.One patient died of sepsis 12 d after the interventional procedure.The remaining 6 patients were survived when they were discharged.The mean follow-up time was 10.5 mo(range 4-16 mo).No patient had recurrent bleeding after discharge.Doppler ultrasound examination verified the patency of hepatic artery and stent-grafts during the follow-up.CONCLUSION:Placement of stent-grafts is an effective and safe procedure for acute life-threatening hemorrhage from ruptured hepatic artery pseudoaneurysm.

Endovascular stent-grafts for acute and chronic type B aortic dissection: comparison of clinical outcomes

Objective To evaluate the early and mid-term results of endovascular repair for acute and chronic type B aortic dissection, and to compare the clinical outcomes between the 2 groups. Methods From May 2002 to December 2006, 50 patients with type B aortic dissection were treated by endovascular stent-graft. There were 23 patients in the acute aortic dissection (AAD) group and 27 patients in the chronic aortic dissection (CAD) group. All patients were followed up from 1 to 54 months (average, 17±16 months).The immediate and follow-up clinical outcomes were documented and compared between the 2 groups. Results Placement of endovascular stent-grafts across the primary entry tears was technically successful in all 50 patients. Compared to the CAD group, the AAD group had a higher percentage of pleural effusion (17.4% vs. 0%, P=0.04) and visceral /leg ischemia (26.1% vs 3.7%, P=0.04). Procedure related complications, including endoleak and post-implantation syndrome, occurred more frequently in the AAD group than in the CAD group (21.7% vs 3.7% and 30.4% vs 11.1%, respectively; P=0.08 and P=0.04). Kaplan–Meier analysis showed no difference in the survival rate at 4 years between the 2 groups (86.4% vs 92.3%, P=0.42 by log-rank test). However, the event-free survival rate was higher in patients with chronic dissection than in patients with acute aortic dissection(96.2% vs 73.9%; P=0.02 by log-rank test). Conclu- sions Endovascular repair with stent-graft was safe and effective for the treatment of both acute and chronic type B aortic dissection. However, both immediate and long term major complications occurred more frequently in patients with acute dissection than in those with chronic dissection.

Short-term results in canines of novel stent-graft design for chimney technique in TEVAR

Introduction:Parallel stent-stent grafting is a major endovascular technique used to preserve the supra-aortic branches during thoracic endovascular aortic repair(TEVAR)of aortic pathologies involving the aortic arch.The short-and mid-term results of this technique are satisfactory;however,endoleak remains a major concern.Thus,here we designed a new chimney stent-graft to decrease the endoleak rate.Aim:To testify the feasibility and safety of the new chimney stent-graft system in a canine model.Material and methods:Six Labrador retrievers were used.Pre-operative data were collected and all operations were performed under general anesthesia.The main and chimney stent-grafts were implanted through the abdominal aorta and left subclavian artery approaches,respectively.Completion digital subtraction angiography(DSA)was performed to confirm the immediate outcomes.All dogs were fed separately for 6 months and sacrificed after aortic angiography.The thoracic aorta and the main and chimney stent-grafts were harvested for histopathologic examination.Results:No complications were found in follow-up DSA.All branch arteries were patent.In?ammatory responses were observed around the stent-grafts in 3 experimental animals,and slight hyperplasia was observed in the surrounding tissues compared with the normal vessels.There was no mural thrombus in the stent,endothelial cells were noted on the inner surface of the stent,and thrombus was formed in the outer skirt and gutter area.The histopathologic examinations revealed similar results to those of gross necropsy observations.Conclusions:This study demonstrated the feasibility and safety of the Longuette stent-graft and the first to report a revised stent-graft specific for chimney technique.

Fatigue Performance of Fabrics of Stent-Grafts Supported with Z-Stents vs. Ringed Stents

Stent-grafts were commercialized rapidly and gained a broad clinical acceptance over the past two decades. However,relatively more recent recognition of particular stent-graft design shortcomings have been identified which need to be addressed. It appears that various stent-graft designs may be more or less resistant to metal fatigue and /or fabric abrasions which can lead to type III and type IV endoleaks over the long term. Therefore,it is necessary to investigate the fatigue performance of the most common stentgraft designs: Z-stents and ringed stents,in a long-term in vitro fatigue simulation environment. This paper aimed to analyze nondestructively( gross observations) and destructively( fabric characteristics,mechanical and chemical properties) in order to put forward suggestions to improve the fabric and stent characteristics that may prevent type III and IV endoleaks. The fabric supported with ringed stent-grafts remained nearly completely intact after 168h. However, the fabric supported with Z-stents demonstrated significant damage. Fabric characteristics and tensile strength of the fibers did not present a significant difference between the control and fatigue simulated specimens. The crystallinity declined for both specimens. The fatigue performance of fabrics supported with ringed stents appears to be superior to that supported with Z-stents. The potential for a dynamic and destructive interaction between the apices of Z-stents which can lead to fraying and /or tearing of the graft fabric must be addressed in future designs.

Total endovascular repair of aberrant right subclavian artery using caster branched stent-graft

A 57-year-old man has 20-year history of hypertension presented with intermittent chronic pain in the chest area and shoulder blades over the last three months.Computed tomographic angiography(CTA)on admission revealed a chronic type B aortic dissection(TBAD)with an aberrant right subclavian artery(ARSA)crossed behind the trachea and bovine aortic arch(Figure IB).

Endovascular stent-grafts for acute and chronic type B aortic dissection: comparison of clinical outcomes

Within the recent months, endovascular repair of aortic aneurysms has become a rather interesting alternative to patients considering open surgery. In the past, the procedure was typically and more solely reserved to a selected group of elderly patients with several co-morbidities.……

Mid-term outcomes of left subclavian artery revascularization with Castor stent graft in treatment of type B aortic dissection in left subclavian artery

Background:Here we analyzed mid-term data of thoracic endovascular aneurysm repair(TEVAR)surgery with Castor single-branched stent graft placement for the management of Stanford type B aortic dissection(STBAD)involving the left subclavian artery(LSA).Methods:Between April 2014 and February 2019,32 patients with STBAD involving a Castor single-branched stent graft were included.We analyzed their outcomes,including technical success rate(TSR),surgical duration(SD),presence of ischemia,perioperative complications,LSA patency,and survival rate(SR),using computed tomography angiography and clinical evaluation during mid-term follow-up.Results:The mean patient age was 54.63±12.37 years(range,36–83 years).The TSR was 96.88%(n=31/32).The mean SD was 87.44±10.89 with a mean contrast volume of 125.31±19.30 mL.No neurological complications or deaths occurred during the study period.The patients had a mean hospital stay of 7.84±3.20 days.At a mean follow-up of 68.78±11.26 months,four non-aortic deaths(12.5%)were observed.The LSA patency rate was 100%(n=28/28).There was only one case of type I endoleak immediately after surgery(3.12%)(type I from LSA).However,none of the patients experienced type II endoleaks,and there were no cases of retrograde type A aortic dissection or stent graft-driven new distal entry.Finally,all patients exhibited good LSA patency.Conclusion:TEVAR using a Castor single-branched stent graft may be a highly feasible and efficient procedure for the management of STBAD involving the LSA.

Case Report of a Pseudoaneurysm of Ascending Aorta Treated by Stent

Pseudoaneurysms of the ascending aorta are a rare complication of aortic and cardiac surgery. In this article, we present a clinical case of a 56-year-old patient with a fortuitous diagnosis of a pseudoaneurysm of ascending aorta that was treated by an endovascular stent-graft. We discuss in this article the diagnostic and therapeutic aspect of the case and the place of endovascular treatment for the ascending aorta.

Endovascular management of visceral artery aneurysms: When to watch, when to intervene?

Visceral artery aneurysms(VAA) include splanchnic and renal artery aneurysms. They represent a rare clinical entity, although their detection is rising due to an increased use of cross-sectional imaging. Rupture is the most devastating complication, and is associated with a high morbidity and mortality. In addition, increased percutaneous endovascular interventions have raised the incidence of iatrogenic visceral artery pseudoaneurysms(VAPAs). For this reason, elective repair is preferable in the appropriately chosen patient. Controversy still exists regarding their treatment. Over the past decade, there has been steady increase in the utilization of minimally invasive, non-operative interventions, for vascular aneurysmal disease. All VAAs and VAPAs can technically be fixed by endovascular techniques but that does not mean they should. These catheter-based techniques constitute an excellent approach in the elective setting. However, in the emergent setting it may carry a higher morbidity and mortality. The decision for intervention has to take into account the size and the natural history of the lesion, the risk of rupture, which is high during pregnancy, and the relative risk of surgical or radiological intervention. For splanchnic artery aneurysms, we should recognize that we are not, in reality, well informed about their natural history. For most asymptomatic aneurysms, expectant treatment is acceptable. For large, symptomatic or aneurysms with a high risk of rupture, endovascular treatment has become the firstline therapy. Treatment of VAPAs is always mandatory because of the high risk of rupture. We present our point of view on interventional radiology in the splanchnic arteries, focusing on what has been achieved and the remaining challenges.

Stent placement is effective on both postoperative hepatic arterial pseudoaneurysm and subsequent portal vein stricture:A case report

To treat postoperative bleeding after hepato-pancreato-biliary surgery, interventional radiology has become essential. We report a case of coincidental pseudoan-eurysm and jejunal varices that were both successfully treated by stent-grafts. After a pancreaticoduodenec-tomy, the patient developed a pseudoaneurysm in the hepatic artery and a stenosis in its periphery. After establishing hepatic arterial flow by placing stent-grafts over both the pseudoaneurysm and the stenosis, the pseudoaneurysm was embolized with microcoils. Nine months later, the patient developed jejunal varices caused by a severe stricture in the main trunk of the portal vein. Percutaneous transhepatic portography was performed and stent-grafts were placed over the stenotic segment. A venoplasty using stent-grafts nor-malized the portal blood flow and the jejunal varices vanished. Although stenosis occurred due to scarred tissues from leakage after pancreaticoduodenectomy, stent-grafts were useful for managing jejunal bleeding post-operatively.

The interactions between bloodstream and vascular structure on aortic dissecting aneurysmal model: A numerical study

Stent-graft implantation is an important means of clinical treatment for aortic dissecting aneurysm （ADA）. However, researches on fluid dynamics effects of stent were rare. Computer simulation was used to investigate the interactions between bloodstream and vascular structure in a stented ADA, which endures the periodic pulse velocity and pressure. We obtained and analyzed the flow velocity distribution, the wall displacement and wall stress in the ADA. By comparing the different results between a non-stented and a stented ADA, we found that the insertion of a vascular graft can make the location of maximum stress and displacement move from the aneurysm lumen wall to the artery wall, accompanied with a greatly decrease in value. These results imply that the placement of a stent-graft of any kind to oc-clude ADA will result in a decreased chance of rupture.

Fatal arterial hemorrhage after pancreaticoduodenectomy:How do we simultaneously accomplish complete hemostasis and hepatic arterial flow?

BACKGROUND Although arterial hemorrhage after pancreaticoduodenectomy(PD)is not frequent,it is fatal.Arterial hemorrhage is caused by pseudoaneurysm rupture,and the gastroduodenal artery stump and hepatic artery(HA)are frequent culprit vessels.Diagnostic procedures and imaging modalities are associated with certain difficulties.Simultaneous accomplishment of complete hemostasis and HA flow preservation is difficult after PD.Although complete hemostasis may be obtained by endovascular treatment(EVT)or surgery,liver infarction caused by hepatic ischemia and/or liver abscesses caused by biliary ischemia may occur.We herein discuss therapeutic options for fatal arterial hemorrhage after PD.AIM To present our data here along with a discussion of therapeutic strategies for fatal arterial hemorrhage after PD.METHODS We retrospectively investigated 16 patients who developed arterial hemorrhage after PD.The patients’clinical characteristics,diagnostic procedures,actual treatments[transcatheter arterial embolization(TAE),stent-graft placement,or surgery],clinical courses,and outcomes were evaluated.RESULTS The frequency of arterial hemorrhage after PD was 5.5%.Pancreatic leakage was observed in 12 patients.The onset of hemorrhage occurred at a median of 18 d after PD.Sentinel bleeding was observed in five patients.The initial EVT procedures were stent-graft placement in seven patients,TAE in six patients,and combined therapy in two patients.The rate of technical success of the initial EVT was 75.0%,and additional EVTs were performed in four patients.Surgical approaches including arterioportal shunting were performed in eight patients.Liver infarction was observed in two patients after TAE.Two patients showed a poor outcome even after successful EVT.These four patients with poor clinical courses and outcomes had a poor clinical condition before EVT.Fourteen patients were successfully treated.CONCLUSION Transcatheter placement of a covered stent may be useful for simultaneous accomplishment of complete hemostasis and HA flow preservation.

Percutaneous coronary intervention following repair of type B aortic dissection:a report of 8 cases

Objective Patients with aortic dissection have a significant incidence of coronary artery disease.The purpose of this study is to evaluate the safety and feasibility of percutaneous coronary stent in patients who have undergone endovascular stent,and to assess the effect of anti-coagulant and anti-platelet treatment on patients'thrombosis process.Methods From January 2005 to July 2007,8 patients who had undergone endovascular stent-graft during the past 1 to 7 months for type B aortic dissection repair,underwent percutaneous coronary intervention(PCI)because of coexisting coronary artery disease.Anti-coagulant and anti-platelet treatments were administrated after PCI according to the standard protocol.Patients were followed up for a mean period of 23 months.Clinical and false lumen status data were collected during the follow-up.Results PCI were technically successful in all 8 patients and no severe complications such as death,paraplegia,renal failure occurred during hospitalization.Complete false lumen thrombosis was observed in 5 patients and incomplete false lumen thrombosis in the remained 3 patients at the end of follow up.There were no major complications such as death,dissection rupture or aneurysm development occurred during the follow-up period.Conclusion Our data implied that PCI can be safely performed in patients with type B aortic dissection who have undergone endovascular stent-graft,without interrupt-ing the thrombosis process.

Repeated Surgery for Recurrent Pseudoaneurysms after Thoracoabdominal Aortic Replacement

Aneurysm or pseudoaneurysm formation in the aortic patch containing the intercostal or visceral arteries is an unusual late complication after thoracoabdominal aortic surgery. We report the case of a 58-year-old woman who had previously undergone thoracoabdominal aortic replacement (Crawford extent II) for dissecting aneurysm. About 12 months after the operation repeated pseudoaneurysmal degenerations occurred at the intercostal or visceral artery reattachment site. They were repaired with open surgery or endovascular stent-graft. The patient recovered without major complications, and computed tomographic scans showed no recurrence of aneurysm or pseudoaneurysm at the sites of repair 1 year after the procedure.

Endovascular treatment of traumatic renal artery pseudoaneurysm with a Stanford type A intramural haematoma:A case report

BACKGROUND Aortic intramural hematoma(IMH) associated with aortic branch tear and intramurally located pseudoaneurysm after blunt trauma has not been reported.Here,we report a case of progressive type A aortic IMH associated with a pseudoaneurysm arising from the injured proximal renal artery after blunt trauma.CASE SUMMARY During logging operations,a 66-year-old man experienced blunt force trauma after being injured by a fallen tree.He arrived at our trauma center with a left flank pain complaint.Computed tomography(CT) revealed a pseudoaneurysm arising from the proximal renal artery(localized within the aortic media) and Stanford type A IMH.A covered stent was deployed along the left main renal artery,bridging the pseudoaneurysm and covering the parent artery,successfully excluding the pseudoaneurysm as confirmed using aortography.However,although the degree of the pseudoaneurysm decreased,follow-up CT revealed remnant pseudoaneurysm,likely caused by an endoleak.Subsequently,a covered stent was additionally installed through the previously deployed covered stent.Successful exclusion of the pseudoaneurysm was confirmed using final aortography.In the 7-mo follow-up CT scan,the IMH and pseudoaneurysm completely disappeared with no evidence of stent-related complications.CONCLUSION Endovascular treatment such as stent-graft placement can be an effective and safe treatment for traumatic renal artery injury.