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.

Endovascular treatment of aortoiliac aneurysms: From intentional occlusion of the internal iliac artery to branch iliac stent graft

Approximately 20%-40% of patients with abdominal aortic aneurysms can have unilateral or bilateral iliac artery aneurysms and/or ectasia. This influences and compromises the distal sealing zone during endovascular aneurysm repair. There are a few endovascular techniques that are used to treat these types of aneurysms, including intentional occlusion/over-stenting of the internal iliac artery on one or both sides, the "bell-bottom" technique, and the more recent method of using an iliac branch stent graft. In some cases, other options include the "snorkel and sandwich" technique and hybrid interventions. Pelvic ischemia, represented as buttock claudication, has been reported in 16%-55% of cases; this is followed by impotence, which has been described in 10%-17% of cases following internal iliac artery occlusion. The bellbottom technique can be used for a common iliac artery up to 24 mm in diameter given that the largest diameter of the stent graft is 28 mm. There is a paucity of data and evidence regarding the "snorkel and sandwich" technique, which can be used in a few clinical scenarios. The hybrid intervention is comprised of a surgical operation, and is not purely endovascular. The newest branch stent graft technology enables preservation of the anterograde flow of important side branches. Technical success with the newest technique ranges from 85%-96.3%, and in some small series, technical success is 100%. Buttock claudication was reported in up to 4% of patients treated with a branch stent graft at 5-year follow-up. Mid- and short-term follow-up results showed branch patency of up to 88% during the 5-6-year period. Furthermore, branch graft occlusion is a potential complication, and it has been described to occur in 1.2%-11% of cases. Iliac branch stent graft placement represents a further development in endovascular medicine, and it has a high technical success rate without serious complications.

Total endovascular repair of an intraoperative stent-graft deployed in the false lumen of Stanford type A aortic dissection: A case report

BACKGROUND A 46-year-old male underwent ascending aortic replacement,total arch replacement,and descending aortic stent implantation for Stanford type A aortic dissection in 2016.However,an intraoperative stent-graft was deployed in the false lumen inadvertently.This caused severe iatrogenic thoracic and abdominal aortic dissection,and the dissection involved many visceral arteries.CASE SUMMARY The patient had pain in the chest and back for 1 mo.A computed tomography scan showed that the patient had secondary thoracic and abdominal aortic dissection.The ascending aortic replacement,total arch replacement,and descending aortic stent implantation for Stanford type A aortic dissection were performed 2 years prior.An intraoperative stent-graft was deployed in the false lumen.Endovascular aneurysm repair was performed to address this intractable situation.An occluder was used to occlude the proximal end of the true lumen,and a covered stent was used to direct blood flow back to the true lumen.A three-dimensional printing technique was used in this operation to guide prefenestration.The computed tomography scan at the 1stmo after surgery showed that the thoracic and abdominal aortic dissection was repaired,with all visceral arteries remaining patent.The patient did not develop renal failure or neurological complications after surgery.CONCLUSION The total endovascular repair for false lumen stent-graft implantation was feasible and minimally invasive.Our procedures provided a new solution for stent-graft deployed in the false lumen,and other departments may be inspired by this case when they need to rescue a disastrous stent implantation.

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.

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.

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.

Role of Grafting Technique on the Success of Stenting Propagation of Two Rose (<i>Rosa</i>sp.) Varieties

The influence of two grafting techniques on the success of stenting (simultaneous cutting and grafting) and some ensuing growth parameters of stentlings were studied under glasshouse conditions. The Avalanch and Peach Avalanch glasshouse rose varieties were utilized as scion and grafted on R. manetti as rootstock. Two grafting techniques namely, splice and omega grafting methods were practiced and graft combinations were inserted in cocopeat-perlit (1:2) medium under mist system. The number of roots, longest root size, shoots and leaf numbers and successful grafting percentage were evaluated after grafting. In Avalanch/R. manetti and Peach Avalanch/R. manetti combinations, higher percentage of successful grafting was observed in the stentlings propagated via omega grafting technique. Furthermore Avalanch/R. manetti stentlings prepared by omega grafting were found to produce more number of roots, shoots and leaves and longest root size as compared to those propagated through splice grafting method. In case of Peach Avalanch/R. manetti combinations propagated via omega grafting more number of shoots was observed as compared to those propagated by splice method. However, these were not significantly different with respect to their leaf numbers. The results showed the superiority of omega grafting procedure.

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.

Angioscopic Observation of an Endoluminal Stent Graft: CT Imaging versus Angioscopic Imaging

We could observe the endoluminal stent graft (SG) following thoracic endovascular aneurysm repair (TEVAR) by a coronary artery angioscope and establish intravascular visualization of SG. The patient was a 70-year-old woman with the distal aortic arch aneurysm and the descending aortic aneurysm, and debranching TEVAR were performed. After 12 months follow up, urgent hospitalization was required for chest pain, and cardiac catheter examination with a coronary artery angioscope was performed. The endoluminal SG was observed. The observation in angioscope which is a video image is better than CT that is a still image, and observation in blood vessel or SG is possible. It may be possible to observe the endoluminal SG, allowing potential investigation of an endoleak, or the covering status of the SG with the native aortic vessel wall, or the state of intimal membrane formation in the endoluminal graft.

Viabahn Stent Graft for Inadvertent Insertion of a Central Venous Catheter in the Subclavian Artery

Subclavian artery (SCA) injuries associated with central venous catheter (CVC) insertion are uncommon yet lethal complications that typically require surgical treatment. This case report presents the case of a 94-year-old man with an iatrogenic right SCA injury resulting from a misplaced CVC. Computed tomography revealed the catheter piercing the right internal jugular vein to enter the right SCA and then reaching the aortic arch. Emergent endovascular treatment was performed, and a 13-mm × 50-mm self-expanding Viabahn stent graft (W.L. Gore & Associates, Flagstaff, AZ, USA) was placed via the right brachial artery. The misplaced catheter was successfully removed under simultaneous postdeployment balloon dilatation. This case highlights the utility of the Viabahn stent graft for iatrogenic right SCA injury caused by a misplaced CVC and presents some insights and tips for a safer procedure.

Which Offers the Best? Stent Graft or Bare Metal Stent for Endovascular Treatment of Aortoiliac Disease

Background: In the present study, it was aimed to compare the stent grafts and bare-metal stents in terms of post-procedural patency, clinical recovery and complications in the subjects with symptomatic aorto-iliac arterial disease. Methods: A total of 79 subjects with symptomatic aorto-iliac arterial disease treated with endovascular methods were included in the present study. Forty three subjects received self-expendable bare metal stent (ev3 Protégé stent system, Endovascular Inc., Plymouth, Minnesota, USA) and 36 subjects received PTFE-covered stent graft (Fluency Plus Stent Graft, Bard Peripheral Vascular, Tempe, Arizona). The subjects were compared after and at Months 1, 6, and 12 following the procedure in terms of Rutherford’s classification, ankle-arm index (AAI), patency rates, and complications. Results: The subjects receiving bare metal stent and stent graft for aorto-iliac arterial disease were followed for averagely 15 months. For the subjects receiving bare metal stent, primary patency rates at months 1, 6, and 12 were 98%, 81%, and 70%, respectively, while secondary patency rate at month 12 was found to be 84%. For the group of stent graft, primary patency rates were found as 97%, 97%, and 92%, respectively and secondary patency rate at month 12 was found to be 94%. Stent grafts were applied at the same time in 2 patients who had metal bare metal because the rupture occurred during the procedure. In the comparison between two groups, the group of stent graft was found to be statistically superior to the other in terms of patency, clinical and post-procedural complications. Conclusion: In conclusion, it was found that the stent grafts were superior to the bare metal stents in terms of patency and complication rates in the subjects with symptomatic aortoiliac disease.

Hybrid Procedure Utilizing Stent Grafts to Stabilize Distal Flaps after Common and Superficial Femoral Endarterectomy

Background: Endarterectomy has long been the standard for common femoral artery (CFA) occlusive disease. Hybrid procedures utilizing endovascular and open techniques have recently been used for revascularization. The purpose of this study was to evaluate the effectiveness of the use of a stent graft to stabilize the distal flap and prevent further dissection after extensive endarterectomy. Methods: All patients from Monmouth Medical Center in Long Branch, NJ from September 2008 to March 2013 who underwent an extensive common and superficial femoral (SFA) endarterectomy combined with the use of a Viabahn (Gore Medical) stent graft to stabilize the distal flap were included in the study. These stents were deployed in the proximal SFA after extensive endarterectomy, under direct visualization, without the aid of fluoroscopy. Due to the location in the SFA, these flaps were not amenable to suture tacking. Results: Fifteen patients met these criteria and were included in our study. Twelve patients underwent femoral endarterectomy for severe claudication and three patients for limb salvage. Technical success was achieved in all 15 patients. Five patients also had stents placed proximally to increase inflow and one patient had an additional stent placed distally to improve outflow. There were no intraoperative or postoperative complications. Conclusion: Stent graft placement allows a more extensive endarterectomy to be performed by stabilizing the distal flap allowing a safe transition into the true lumen that is not possible with suture tacking.

Custom Made Fenestrated Stent Graft Collapse after Thoracic Endovascular Aortic Repair: A Case Report

We present a case of stent graft collapse after performing thoracic endovascular aortic repair with a custom-made fenestrated stent graft. The patient was a 70-year-old woman with an asymptomatic aneurysm of the distal aortic arch, and thoracic endovascular aortic repair was performed. The patient showed a blood pressure difference between the left arm and the right arm on postoperative day (POD) 17 prompting the performance of a chest computed tomography scan which revealed stent graft collapse. She then underwent staged debranching of thoracic endovascular aortic repair. Stent graft collapse is a rare but well-described complication of thoracic endovascular repair. Therefore, patients who undergo such a procedure should be carefully monitored for signs and symptoms, which suggest the possibility of stent collapse.

Short-term efficacy of unibody single-branched stent in the treatment of lesions involving the left subclavian artery:two-year follow-up outcomes

The development of thoracic endovascular aortic repair(TEVAR)technology avoids the risk of patients opening the chest and is widely used in Stanford B-type dissection.[1–3]However,because TEVAR technology has clear requirements for vascular anatomy of the lesion,it limits its application to some patients.In the shortcomings of the proximal anchor zone,coverage of the left subclavian artery(LSA)origin without revascularization during TEVAR appears to have increased risk of stroke,upper extremity ischemia and paraplegia.[4]

Effect of Time, Cultivar and Rootstock on Success of Rose Propagation through Stenting Technique

An experiment was undertaken to study the effects of two grafting times (1st of June and end of September) as well as kind of rootstock on growth and rooting of rose stentlings. Two Rosa species i.e. R. canina and R. manetti were selected as rootstock and three different hybrid tea rose cultivars namely Avalanch, Peach Avalanch and Dolcevita were grafted on them as scion through omega and splice techniques. The growth parameters were collected 57 days after grafting. The highest average of rooting, healing percentage, numbers of root, shoot and leaves were seen in September grafted plants. In overall Rosa canina was the best rootstock for Avalanch cultivar. Other observations did not lead to any prominent result as it varied with time of grafting, scion and rootstock cultivars.

Repair of a common bile duct defect with a decellularized ureteral graft

AIM To evaluate the feasibility of repairing a common bile duct defect with a decellularized ureteral graft in a porcine model.METHODS Eighteen pigs were randomly divided into three groups. An approximately 1 cm segment of the common bile duct was excised from all the pigs. The defect was repaired using a 2 cm long decellularized ureteral graft over a T-tube(T-tube group, n = 6) or a silicone stent(stent group, n = 6). Six pigs underwent bile duct reconstruction with a graft alone(stentless group). The surviving animals were euthanized at 3 mo. Specimens of the common bile ducts were obtained for histological analysis.RESULTS The animals in the T-tube and stent groups survived until sacrifice. The blood test results were normal in both groups. The histology results showed a biliary epithelial layer covering the neo-bile duct. In contrast, all the animals in the stentless group died due to biliary peritonitis and cholangitis within two months post-surgery. Neither biliary epithelial cells nor accessory glands were observed at the graft sites in the stentless group.CONCLUSION Repair of a common bile duct defect with a decellularized ureteral graft appears to be feasible. A T-tube or intraluminal stent was necessary to reduce postoperative complications.

Obstruction of a Popliteal Artery Stent of a Patient with Popoiteal Artery Entrapment Syndrome

We encountered a popliteal artery entrapment syndrome (PAES) patient who was treated with stent placement for popliteal artery without correcting an abnormal muscular structure that compresses popliteal artery in another institution. The popliteal artery stent was occluded one year after the stent placement. The patient was treated with bypass graft by reversed saphenous vein. Interventionists should be cautious with stent placements for popliteal artery without adjusting the anomalous musculotendinous structure in patients with PAES.

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.

体外预开窗联合束径技术在复杂主动脉病变中的应用

目的评价体外预开窗联合束径技术在复杂主动脉病变中的应用价值。方法回顾性收集2019年12月至2022年5月郑州大学第一附属医院血管外科收治的接受体外预开窗联合束径技术腔内修复治疗的9例复杂主动脉病变患者的临床资料,其中Stanford B型主动脉夹层4例,复杂腹主动脉瘤5例。分析手术成功率、手术时间、住院时间、围手术期死亡率、随访情况。结果9例复杂主动脉病变患者中6例接受三开窗,3例接受四开窗,共重建分支动脉血管30条,植入分支支架(BSG)26条。手术成功率为100.0%(9/9),无术中死亡病例。手术时间211~440 min,平均(333.0±70.8)min。住院时间10~33 d,平均(21.8±7.6)d。1例患者在围手术期死亡,围手术期死亡率为11.11%(1/9),死因为呼吸循环衰竭。术后随访时间0.2~14.6个月,平均随访时间(6.6±5.2)个月;随访过程无患者死亡,再处理2例(25.00%),1例患者出现左肾动脉分支支架内血栓形成,予以机械抽栓并球囊扩张,1例患者右肾动脉分支支架脱入主体支架内,予以腔内技术取出并补装BSG,其余患者主动脉病变重塑良好,无不良并发症。结论体外预开窗联合束径技术腔内修复治疗复杂主动脉疾病的短中期效果满意,具有较好的安全性、可行性。