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Objective To study the mechanical properties and degradation behavior of biodegradable silicon-covered magnesium alloy stent in vitro,to investigate the technical feasibility of its implantation into rabbit esophagus and to observe the tissue reaction in vivo.Methods The mechanical compression recovery properties and the degradation behavior of biodegradable silicon-covered magnesium alloy stent were tested in vitro.A total of 30 healthy Holland rabbits were randomly divided into silicon-covered magnesium alloy stent group (n=15) and control group (n=15).For rabbits in the silicon-covered magnesium alloy stent group fluoroscopy-guided insertion of the stent into the lower third segment of esophagus was conducted,while for rabbits in the control group no intervention was adopted.One,2 and 4 weeks after the implantation of the stent,esophagography was performed for all rabbits of both groups,and each time every 5 rabbits from both groups were sacrificed,the specimens were collected and sent for histological examinations.Results In vitro test indicated that biodegradable silicon-covered magnesium alloy stent had good flexibility and elasticity,and in phosphate-buffered saline with pH 4.0 or pH 7.4 it degraded more slowly than bare magnesium alloy stent.In vivo test showed that the stent implantation could be well tolerated by all experimental rabbits.Before stent insertion the esophageal diameter was(9.2±0.8) mm,and at one,2 and 4 weeks after stent insertion the esophageal diameters were (9.7±0.7) mm,(9.6±0.8) mm and (9.6±0.5) mm respectively (P＞0.05).In the silicon-covered magnesium alloy stent group,stent displacement occurred in 6 rabbits in one week (n=l),2weeks (n=1) and 4 weeks (n=4).After stent implantation,the tissue reactions such as esophageal wall injury,collagen deposition,etc.were not obviously different from those in the control group (P＞0.05).Conclusion It is technically feasible to insert silicon-covered magnesium alloy stent into the rabbit's esophagus,the stent can provide sufficient support for at least 2 weeks,the stent displacement rate is low and acceptable,and no severe esophageal wall injury and collagen deposition are observed.
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Objective To assess the clinical value of percutaneous bone cement fusion in treating stress fracture of vertebral body that is adjacent to pseudoarthrosis in patients with ankylosing spondylitis.Methods The clinical data of 4 ankylosing spondylitis patients with stress fracture of vertebral body adjacent to pseudoarthrosis,which was treated with percutaneous bone cement fusion,were retrospectively analyzed.Bone cement fusion through injection of bone cement was performed for 4 vertebral segments.Visual analogue scale (VAS) of pain and Oswesty disability index (ODI) were determined before and after operation,the results were compared,and the improvements of pain and daily activity were evaluated.Results The operation was successfully accomplished in all the 4 patients.The mean used amount of bone cement for each vertebral segment was 14.5 ml.Small amount of bone cement extravasation was observed in one patient,but no severe clinical complication occurred.The mean VAS score decreased from preoperative 9 points to postoperative 3.5 points;ODI score decreased from preoperative 43.8 points to postoperative 14.5 points.After the treatment,the pain was obviously relieved and the daily activity was markedly improved.Conclusion For the treatment of stress fracture of vertebral body that is adjacent to pseudoarthrosis in patients with ankylosing spondylitis,percutaneous bone cement fusion is minimally-invasive,safe and effective.
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The authors report one case of primary hepatic neuroendocrine carcinoma associated with multiple liver metastases. A patient was a 41-year-old female. In 2010, B-ultrasound examination revealed that there were multiple space-occupying lesions in the liver, and hepatic hemangiomas was considered to be the diagnosis. Then, the patient was followed up regularly. In Aug. 2013, B-ultrasound examination indicated that the hepatic lesions were significantly enlarged. Multi-detector CT scanning and MRI examination were performed, and still the diagnosis of multiple hepatic hemangiomas was suggested. On CT and MRI the lesion presented as a well-circumscribed hypervascular tumor with “fast-in and slow-out” enhancement pattern. On MRI, the lesion was characterized by multiple nodules. Needle biopsy was carried out, and the pathological and immunohistochemical diagnosis was metastatic neuroendocrine tumor. Systemic examination did not find the primary lesion. Therefore, primary hepatic neuroendocrine carcinoma associated with intra- hepatic metastases was diagnosed. The patient was treated with transcatheter arterial chemoembolization. The drugs used were 100 mg Oxaliplatin+one bottle of gelatin sponge particles(300-500μm)+10 ml iodized oil, and micro-pump infusion of 100 mg oxaliplatin(99 mg/h) through catheter was also employed. Clinically, primary hepatic neuroendocrine carcinoma is extremely rare. In combination with the medical literatures, the authors attempt to make a preliminary discussion on the clinical characteristics, differential diagnosis, treatment and prognosis of primary hepatic neuroendocrine carcinoma.
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Stent implantation plays a more and more important role in the treatment of benign esophageal stenosis. Metal stents are most commonly used in the clinical practice, which can be classified into permanent stents and temporary retrieval stents. Permanent implantation of metal stents is easy to cause complications such as inflammatory hyperplasia, in-stent restenosis, perforation, bleeding, etc. Temporary retrieval stents should be removed with one week after it is implanted in order to avoid esophageal scar tissue repair and in-stent tissue hyperplasia, which can cause difficulty in its removing and produce higher recurrence rate of esophageal restenosis. Clinically, drug-eluting stents have already been used in cardiovascular system procedures, but at present the gastrointestinal drug-eluting stents are still in development and animal experiment stage. Biodegradable magnesium alloy stents have been widely employed in cardiovascular system procedures. With the rapid development of biological engineering materials, drug-eluting magnesium alloy stent has become a hot spot and the frontier in research field. This paper aims to make a comprehensive review about the current research status and prospect of the drug-eluting magnesium alloy stents, focusing on the stent technology, stent molding, coating modification, and the treatment of drug-eluting.
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Objective To investigate the method for effective establishment of nude rat tumor xenograft model of human lung cancer cells A549 in order to provide the experimental basis for tumor-related interventional research in vivo. Methods A549 cell lines were subcutaneously transplanted in nude rats, then single-cell suspension or tumor tissue block were prepared when the tumor lesion was established. The single-cell suspension and tumor tissue block were transplanted into subcutaneous tissue behind ear in rats. The tumor formation rate, growth situation and cell cycle of primary xenograft tumor group, the secondary single-cell suspension group and the secondary tumor block group were evaluated. The results were analyzed. Results The tumor formation rate of the secondary tumor block group was significantly higher than that of the other two groups. The tumor cells quickly proliferated with less tumor variation. Tumor cell cycle analysis indicated that G2/M ratio of the secondary tumor block group was remarkably higher than that of the other two groups. Conclusion Transplantation with tumor tissue block can significantly increase the tumor formation rate of human lung cancer cells A549 in experimental rats. This technique is an effective method for the establishment of nude rat tumor xenograft model.
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Objective To compare the inhibiting effect on human lung adenocarcinoma who were treated with gem?citabine combined with cisplatin chemotherapy through either arterial or intravenous route to explore the optimum adminis?tration route. Methods Human lung adenocarcinoma derived A549 cells were transplanted into 40 BALB/c-nu mice to es?tablish lung cancer model. The models were divided into 4 groups:animals in arterial or intravenous chemotherapy groups were treated with gemcitabine 150 mg/kg combined with cisplatin 10 mg/kg through either arterial route or intravenous route. Animals in negative control group were given normal saline through caudal vein while animals in sham operation group were treated with normal saline via arterial route. Then dynamical change of tumor volume and tumor inhibiting rate were assessed , and Bcl-2 and Caspase 3 expressions were investigated using western blot. Finally inhibiting effect were compared between these two different administration routes. Results Transplanted tumors in arterial and intravenous che?motherapy groups (especially in arterial group) were suppressed, in terms of mass of tumor(g:1.91±0.19, 2.61±0.21 vs 4.58± 0.46), compared to the control group (P<0.05). Furthermore, tumor inhibiting rates in arterial chemotherapy group and ve?nous chemotherapy group are 57.6%and 42.4%respectively (P<0.05). Expression of Bcl-2 was down regulated while ex?pression of Caspase-3 was up regulated upon both arterial and intravenous chemotherapy. And arterial route showed much more obvious tumor apoptosis effect than venous route. Conclusion Arterial route of gemcitabine combined with cisplatin for lung adenocarcinoma treatment is more effective to restrain the tumor growth in clinical application.
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Objective To evaluate the flexibility and efficacy of the Willis covered stent in the treatment of distal internal carotid artery(DICA)aneurysms.Methods The study was approved by the anthors' institutional review board,and the research was conducted by the authors' institution and the MicroPort Medical Company(Shanghai,China).Thirty-one patients with 33 DICA aneurysms were considered for treatment with a Willis covered stent.The angiographic assessments were categorized as complete or incomplete occlusion.The data on technical Success,initial and final angiographic results,mortality,morbidity,and final clinical outcome were collected,and follow-up was performed at 1,3,6,and 12 months and yearly after the procedures.Results Navigation and deployment of the covered stents were succssfnl in 97.6%(41 of 42;95%confidence interval[CI]:93%,102%)of the attempted stent placement procedures.The initial angiographic results showed a complete occlusion in 23 patients with 25 aneurysms(of 32 aneurysms,78.1%[95%CI:63%,93%])and an incomplete occlusion in seven patients with seven aneurysms(21.9%).The angiographic follow-up(mean,14 months[95% CI:12,15 months])findings exhibited a complete occlusion in 27 patients with 29 aneurysms(of 31 aneurysms,93.5%[95%CI:84%,103%])and an incomplete occlusion in two aneurysms(6.5%),with a mild in-stent stenosis in two patients.The clinical follow-up(mean,27 months[95% CI:23,30 months])demonstrated that 15 patients experienced a full recovery and 14 patients improved.Conclusion The preliminary results demonstrate good flexibility and efficacy of the Willis covered stent in the treatment of DICA aneurysms in selected patients:longer follow-up and expanded clinical trials are needed.
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Objective To report our experiences in the treatment of recurrent intracranial aneurysms with re-coiling or covered stents.Methods A total of 291 patients with 305 intracranial aneurysms were treated with detachable coils.and 41(28.9%)of 142 patients with aneurysms in the intemal carotid artery had a recurrent aneurysm during the follow-up period.For this study,31 recurrent aneurysms in 31 patients who had angiograms within 6 months following retreatment with detachable coils(group A,n=20)or covered stents(group B.n=11)were analysed.Aneurysms were categorised as complete or incomplete occlusion via angiographic assessment and graded as full recovery,improvement,no change or deterioration via clinical assessment.Data regarding technical success,initial and final angiographic results,final clinical outcome were collected and analysed postoperatively.Results Coil embolisation and covered stent placement.were technically successful in all recurrent aneurysms.The initial angiographic results showed complete occlusion in 11 patients(55%)in group A and in eight(72.7%)in group B(P=0.452),and the final angiographic results exhibited complete occlusion in 10 patients(50%)in group A and in 11(100%)in group B(P=0.005).There were no significant differences in technique success or final clinical outcome between the two groups.Conclusions Recurrent aneurysms after coiling can be successfully treated and occluded with re-coiling or covered stent placement.However,covered stents seem to be more effective than re-coiling with regard to complete occlusion of recurrent aneurysms.
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Objective Complicated aneurysms located in the cisternal segment of the internal carotid artery(ICA-CSA)present unique therapeutic difficulties.This study is to discuss the feasibility of the Willis stent-graft in treating complicated ICA-CSA by comparing its effect with that of coiling therapy.Methods Willis covered stents were employed in 19 complicated ICA-CSAs(group A),while coils were used in 17 complicated ICA-CSAs(group B).Follow-up angiography was performed to investigate aneurysm recurrence,endoleak and parent artery(PA)stenosis.Kaplan-Meier curves were constructed to compare the recurrencefree and PA stenosis-free rate in both groups.Results Total exclusion was immediately achieved in 13 ICACSAs and minor endoleaks presented in 5 cases in group A.Total or near-total occlusion was achieved in 7 ICA-CSAs.subtotal occlusion in 8 and partial occlusion in 2 cases in group B after coiling.Acute thrombosis occurred in 1 patient in either group and re-hemorrhage happened in 1 patient after coiling.Follow-up angiography in group A revealed that 16 ICA-CSAs were completely isolated,with two parent arteries showing mild in-stent stenosis.Eighteen months after the procedure,Kaplan-Meier analysis showed that the recurrence-free rate was 93.3%and 50%,while the stenosis-free rate of parent artery was 87.5%and 100% in group A and in Group B,respectively.In group A and group B the clinical neurological symptoms were fully recovered in 9 and 9,obviously improved in 3 and 5,unchanged in 2 and 2,and aggravated in one and 0 patients,respectively.Conclusion The implantation of Willis stent-graft is a feasible endovascular therapy for complicated ICA-CSAs.When the parent artery is very tortuous or when the risk that a main collateral branch may be wrongly covered and occluded is present,the implantation of Willis covered stent can not be taken as the treatment of first choice.
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Objective To establish a carotid siphon aneurysm model in dogs in order to test the mechanical features of a newly-designed Willis covered stent-graft and to investigate the histological reaction of the stent-implanted vessel during a follow-up period of 12 months.Methods Twenty-four saccular sidewall aneurysms were surgically created in twelve dogs(group A)and 12 carotid siphon aneurysms in another twelve dogs(group B).A Willis stent-graft was implanted in each aneurysm.Angiography was performed immediately after the procedure and 1,3,6 and 12 months after the implantation to investigate the aneurysm isolation,endoleak,stent angulation,and the patency or restenosis of the parent artery.Light and scanning electronic microscopy were used to identify aneurysmai sac thrombi,intima hyperplasia and endothelial progress of the stent-loaded arterial segment.Results In group B,postoperative immediate angiography demonstrated that two aneurysms had mild endoleak and three stents became angulated.Follow-up exam 12 months after the procedure revealed that all previous endoleaks disappeared,one parent artery became occluded and three parent arteries developed mild stenosis(＜50%).In group A.occlusion of parent artery was seen in one and mild stenosis(＜50%)in 2 cases.Electronic microscopy revealed new intima formation in all stents,and all aneurysmal sacs were filled with thrombi.In group B.the endothelialization process was not completed until 12 months after the stent implantation,and a marked correlation existed between endothelial cell arrangement and the hemodynamic orientation.Conclusion It is feasible to treat carotid-siphon aneurysm in dog with a Willis stent-graft.The complete endothelialization of the covered stent in tortuous vessel takes longer time than that in rather straight vessel.
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Objective To evaluate the role of transarterial chemoembolization (TACE) as an adjuvant therapy in patients with hepatocellular carcinoma (HCC) treated with hepatectomy. Methods Clinical data of 386 consecutive patients who underwent hepatectomy for HCC were analyzed retrospectively.Of the 386 patients, 156 patients did not undergo TACE served as controls (non-TACE group), the remaining 230 patients underwent TACE (TACE group) preoperatively (n=71), postoperatively (n=86), or both (n =73). For the purpose of comparison, patients who did not undergo preoperative TACE were assigned to group A (n=242), and those patients who underwent preoperative TACE were assigned to group B (n =144). Patients cumulative survival rates were calculated by survival table and analyzed using Kaplan-Meier survival curves. Results There were significantly higher complete necrosis rates in group B (18/144) than those in group A (0/242) ( P ＜ 0.01). The difference between the survival rate of patients with complete necrosis and those with incomplete necrosis was statistically significant (P＜0.01).The 1-,3-,5-and 10-year survival rates were 90.4%(66/73),72.9%(42/73),51.9%(22/73) and 25.4%(2/73) in combined TACE group, 74.0% (50/71) ,46.2%(28/71) ,27.3%(5/71) and 0(0/71) in preoperative TACE group, 88. 0% (73/86) ,59. 6% (39/86) ,36. 7% (11/86) and 0(0/86) in postoperative TACE group, and 75. 8% (110/156), 63.4% (48/156), 31.0% (13/156) and 23.9% (10/156) in non-TACE group,respectively. Combined TACE group got a significantly higher survival rate compared with non-TACE group or preoperative TACE group or postoperative TACE group (P＜0.05). The survival rates in either preoperative or postoperative TACE group were not significantly better than those in non-TACE group (P＞0.05).Conclusions As an adjuvant treatment, combined pre-and post-operative TACE can increase survival rate in patients with surgically resectable HCC. No significant benefit for patient's long term survival when either preoperative or postoperative TACE was performed in addition to surgery.
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Objective To investigate the technique of transarterial embolization of dural carotidcavernous fistulas(DCCFs)with low concentration(14%-25%)of n-butyl-cyanoacrylate(NBCA)and determine its value.Methods Eight patients with DCCFs were treated by transarterial embolization with low concentration of NBCA using a wedged microcatheter.Of the 8 patients,5 had unsuccessful transvenous embolization and 3 could not be treated with transvenous embolization.Results Transarterial embolization with low concentration of NBCA using a wedged microcatheter resulted in complete obliteration of the affected cavernous sinus and related shunts in 5 patients,no residual arteriovenous shunt was demonstrated on postembolization angiography.On clinical and angiographic follow-up 6-12 months later,complete resolution of clinical symptoms was observed in all 5 patients and there were no recurrent or residual DCCFs found.Partial obliteration of the involved cavernous sinus and the related shunt was achieved in the remaining 3 patients on immediate post-procedure angiography,but the volume of shunt diminished significantly.On clinical and angiographic follow-up 3 months later,in 2 patients,clinical symptoms were improved and the arteriovenous shunts were diminished;in the third patient,clinical symptom resolved and the shunt was obliterated.There were no major complications except for the transient worsening of ocular symptoms due to Ⅵ cranial nerve palsy in 1 patient.Conclusions Transarterial embolization of DCCFs with low concentration of NBCA using a wedged microcatheter was a safe and effective treatment method.It is an optimal alternative for the patients with DCCFs in which transvenous route was unsuccessful,or impossible.
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Objective To assess the efficacy and safety of a newly-designed temporary covered cardia stent for the treatment of achalasia in canine models and to investigate the histopathological changes at different points of follow-up time after the stent was removed. Methods The canine achalasia model was created by injecting benzyl-dimethyl-tetradecyl ammonium chloride (BAC) circumferentially into the lower esophageal sphincter (LES) of the dogs. Twenty-four dogs with achalasia were randomly and equally divided into two groups with 12 dogs in each group:control group (using routine esophageal stents) and study group (using newly-designed temporary covered cardia stents). Under fluoroscopic guidance stents were implanted in the esophagus and were taken away from the esophagus 4 days after stent insertion in experimental dogs of both groups. LES pressures and timed barium esophagography (TBE) were performed in all dogs before and immediately after the stenting procedure,as well as at one week,3 and 6 months after the stent was removed. Every three dogs were sacrificed each time at one week,3 and 6 months after the stent was removed. The esophageal cardia was excised and sent for pathological examination. Results All animals well tolerated the stent insertion / removal and the follow-up procedures. No severe complications such as esophageal perforation occurred. Comparison between two groups showed that stent migration occurrence was much lower in study group (n = 1) than that in control group (n = 5). The reduction of LES pressures in study group was more significant in comparison with control group (at 6-month follow-up,P = 0.027). The difference in barium column product (height ? width) between 0-min and 5-min TBE was statistically significant in study group (at 3-month follow-up,P = 0.009). Integrated analysis of multi-comparison for LES pressures among subgroups of each group revealed that the dogs in study group exhibited better outcomes than the dogs in control group. Both proliferating cell nuclear antigen (PCNA) and ?-smooth muscle actin (?-SMA) immuno-staining revealed that the inflammatory reaction reached its peak at 1-month follow-up. Trichrome staining indicated that the collagenous fiber proliferating index inclined to be stable at 3-month follow-up. Conclusion In treating achalasia in canine models the newly-designed temporary covered cardia stent is superior to the routine esophageal stent in respect of safety and efficacy.
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Stent implantation plays an significant role in the interventional therapy, mainly with permanent stent, possessing many disadvantages such as restenosis and inflammatory hyperplasia and can thus hardly be used in children and nonmalignant stenosis. Biodegradable stent has theoretical capability to solve these problems and acquires a bright future. Nowadays, with the development of material industry and manufacture craft, biodegradable stent technique has turned up to be mature in last decades. Through the strict animal experiments and prophase of clinic application, satisfactory result has been acquired. We believe that bioabsorbable stent will be widely used in many benign diseases which would be a good supplement for permanent stent in the near future.
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Objective To evaluate the toxic effects and efficacy of the intra-arterial chrono-chemotherapy on patients with liver metastasis arised from colorectal cancer. Methods Chemotherapy of 42 patients were randomly divided into group A (n = 20) with continuously constant arterial infusion, and group B (n = 22) with arterial chrono-modulated infusion. And the toxic effects and efficacy of two groups were compared. Results A significant difference was found in the toxic effects of digestive system between the two groups. The treatment response was similar in the two groups. Conclusions Intra-arterial chrono-chemotherapy may decrease the toxic effects and improve the life quality of these patients.
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Objective To observed the long-term follow-up of the two types of interventional procedure for achalasia. Methods The study cohort was comprised of 140 patients of achalasia including 70 patients treated under fluoroscopy with pneumatic dilation (group A) and 70 with temporary partially covered metal stent dilation (group B). Results One hundred and forty dilations were performed on the 70 patients of group A with complications of chest pain (n=35), reflux (n=18), and bleeding (n=8); 38 atients of relapsing dysphagia during a 12-month follow-up, and 50 patients out of 60 of recurrent dysphagia during a 36-month follow-up. Seventy partially covered expandable metal stents were temporarily placed in the 70 patients of group B and withdrawn after 3-7 days via gastroscopy with complications of chest pain (n=28), reflux (n=15), and bleeding (n=9); 7 patients out of 70 exhibited dysphagia relapse during a 12-month follow-up, and 9 out of 58 patients exhibited dysphagia relapse during a 36-month follow-up. All the stents were inserted and withdrawn successfully. The follow-up in groups A-B lasted for 12-96 months. Conclusion Temporary partially covered metal stent dilation is one of the best methods of interventional procedure for achalasia in long-term follow-up. (J Intervent Radiol,2005,14:171-174)
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Objective To evaluate the mid- and long-term radiological outcomes of cerebral aneurysms with GDCs embolization.Methods One hundred and sixty-two patients with 173 aneurysms embolized with GDCs underwent angiographic follow-up from 1 to 54 months post-operatively and were retrospectively reviewed. Three neuro-radiologists reviewed each angiogram and made a comparison between initial and follow-up angiograms. Morphological outcomes were evaluated as follows: unchanged; progressive thrombosis; and re-opening or re-growth. Results Of 173 aneurysms with GDC embolization, 142 aneutysms had total or nearly total occlusion, 23 subtotal occlusion and 8 partial occlusion shown on initial angiograms. The incidence of re-opening was 17.1% (13/76) in less than 3 months, and 6.2% (6/97) between 3 and 6 months postoperatively. Four aneurysms showed recurrency(2.3%) on second follow-up angiography in one year after procedure and one-year cumulative recurrent rate was 13.3% of 56 aneurysms with the third follow-up angiography in the post-operation period of 12 to 54 months, four showed a little enlargement and the cmnulative recurrent rate so far was 20.2% (35/173). Conclusions The direct and main causes for aneurysmal recurrence are incomplete and loosening packing. The first angiographic follow-up is recommended to be performed at 3 months or earlier after the procedure, especially in aneurysms with initial incomplete occlusion. Re-treatment with balloon- or stent-assisted coil embolization is recommended in re-opening aneurysms. (J Intervent Radiol,2005,14:472-479)
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Achalasia is a primary esophageal motility disorder, with the main symptom of dysphagia; and caused by the tonus increase and abnormal relaxation of the lower esophageal sphincter(LES). The etiology remains unclear, the objective of the current treatment approaches for achalasia containing the reduction of the LES tone and obstruction to relieve the patients' symptoms; including pharmacologic treatment, botulinum toxin treatment, surgical myotomy, pneumatic dilatation and cardia stent dilatation. The temporary cardia stent dilatation possesses some better advantages and effects; and ought to be the first choice of minimal invasive interventional management for achalasia.
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Objective To assess the effectiveness and safety and biocompatibility of balloon-expanding stainless steel stents (SSS) covered with polyurethane membrane (PUM), expanding poly teflon ester membrane(ePTFEM)and biomembrane (BM) in the treatment of experimental saccular aneurysms of carotid arteries in canine models.Methods 36 experimental saccular aneurysms of carotid arteries in 20 canines were created successfully by sugery. Experimental aneurysms were treated with covered stents including twelve PUM-SSS, twelve ePTFEM-SSS and twelve BM-SSS for each twelve canines repectively. They were placed endovascularly in the common carotid arteries covering the orifice of aneurysms. Follow up angiography was performed immediately after the procedure and 2, 4 and 12 weeks afterwards under the control of conventional anticoagulation. The animals were then sacrificed for histopathologic and statistical investigation. Results 36 stents were placed successfully in the target arteries. The complete patency rates of PUM-SSS, ePTFEM-SSS and BM-SSS were 25.0%, 41.7% and 91.7% respectively. Histological analysis indicated that all treated aneurysmal pouches were filled with thrombus. Stent wires were found to be located deep within the vessel wall and encased by extension of the tunica intima. Endothelialization of BM-SSS groups already began at the 2nd week which was earlier than that of PUM-SSS and ePTFEM-SSS. Various degrees of degenerative cells were seen under the transmission electron microscopy without surface erosion of stents. Conclusion Placement of covered stent endovascularly is expedient, safe, and effective. BM-SSS provides the best mechanical behavior, physiochemical stability, anticoagulative ability and biocompatibility.
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Objective To evaluate the effects and methods of interventional therapy of the atherosclerotic renal artery stenosis(ARAS).Methods 28 cases of ARAS were implanted with stents by guiding catheter or guidewire exchanging, 31 stents were implanted (Palmaz stent in 22, Wallstent in 4, and Symphony stent in 5). Follow up was undertaken for 6 months to 1 year, together with recording the blood pressure, creatinine, the effective number of antihypertensive medication and comparing with those before the procedure. Results Stents were implanted successfully in all cases. Complication of renal arterial embolism happened in 2 cases with recanalization by guidewire exchanging. Restenosis happened in 4 cases.Conclusion Stent implantation for renal artery stenosis by guiding catheter is an ideal method or probably the chief interventional therapy to preserve the renal function.