Customized and in situ fenestrated stent-grafts:A reinforced poly-ε-caprolactone branch cuff designed to prevent type III endoleaks and enhance hemodynamics

Superior long-term anchorage of the bridging stent-grafts from the fenestrated main body endograft could be achieved with the addition of a flared cuff,capable of preventing the previously observed fabric fraying around the fenestration as a result of the balloon angioplasty of the seal zone.This novel stent cuff design will also facilitate more complete biointegration of the devices,eliminate the hemodynamic variation as well as significantly reduce the possibility of a Type III endoleak.The feasibility of this concept is demonstrated by observations made from in-situ tests performed in a Beta endograft design.Flared cuffs made of poly(ε-caprolactone)supported with a weft-knitted polyester structure can be manufactured with various configurations to optimize the transition from the main body of the endograft,thus preventing the currently marketed designs’hemodynamic perturbation while also promoting endograft biointegration.This concept represents an evolution in branch graft design,which may enhance the long-term durability of customized fenestrations and open new applications for in-vivo graft fenestration in the near future.Further ongoing investigation to optimize its structure,X-ray opacity,fixation to the flared stent,and material biocompatibility are still required to build upon this concept’s proof.

Incidental Finding of a Fenestrated Vertebrobasilar Junction Aneurysm

Basilar artery fenestration is a rare anatomical variation resulting from the failed fusion of the two vertebral arteries during embryonic life. In order of frequency, it is the second most common location of vascular fenestrations after the anterior communicating artery. Vertebrobasilar junction aneurysms are uncommon but often associated with basilar artery fenestration. We report the case of a fenestrated vertebrobasilar junction saccular aneurysm in a 57-year-old woman. The diagnosis was incidentally made on CT angiography which found the anatomical variant and the aneurysm. The radiological features illustrating this association are detailed here and a brief discussion of its pathogenesis and management was made. Vertebrobasilar junction aneurysms are rare and their presence should suggest an associated basilar fenestration.

Three-Dimensional Cerebral Aneurysm Models for Surgical Simulation and Education—Development of Aneurysm Models with Perforating Arteries and for Application of Fenestrated Clips

We modified a three-dimensional cerebral aneurysm model for surgical simulation and educational demonstration. Novel models are made showing perforating arteries arising around the aneurysm. Information about perforating arteries is difficult to obtain from individual radiological data sets. Perforators are therefore reproduced based on previous anatomical knowledge instead of personal data. Due to their fragility, perforating arteries are attached to the model using hard materials. At the same time, hollow models are useful for practicing clip application. We made a model for practicing the application of fenestrated clips for paraclinoid internal carotid aneurysms. Situating aneurysm models in the fissure of a brain model simulates the real surgical field and is helpful for educational demonstrations.

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.

LONG-TERM OUTCOMES OF FENESTRATED DISCECTOMY FOR LUMBAR DISC

Objective To evaluate the long-term outcomes of fenestrated discectomy for lumbar disc herniation and analyze the correlative influence factors. Methods Eighty-two cases of lumbar disc herniation, from February 1996 to May 1999, were retrospectively studied. All patients were treated with simple fenestrated discectomy. The average follow-up time was 8 years and 7 months （from 7 years tolO years and 3months）. There were 13, 38 and 31 cases at 13 - L4, L4 - L5 and L5 - S1 level, respectively. Results The average scales before operation were as following ： Japanes Orthopaedics Association （ JOA ） scale 6. 5 （ 5 - 9 ） , visual analysis scale （ VAS） of low back pain4.8 （0-8）. and VAS of sciatica 7.2 （4-10）. At the final follow-up, the above parameters were 13.2 （ 10 - 14 ）, 1.8 （0 - 10） and 1.2 （0 - 7）, respectively. The average increase ratio of JOA scale was 78. 8%. The average disc-vertebra height ratio （ Mochida method） was 80.2%. At the final follow-up, 7 cases reoccurred disc herniation. The final clinical satisfaction rate was 80% （ modified Macnab method ）. Conclusion With appropriate surgical indications, the successfid long-term outcomes could be expected with fenestrated discectomy. Discectomy improves sciatica to a greater extent than low back pain. The occurrence of low back pain is related to intervertebral disc height, segment stability, disc degeneration, and lumbar muscle disability.

骨性Ⅱ类高角患者正畸治疗前后牙槽骨形态特征的锥形束CT回顾性研究

目的:通过锥形束CT(cone beam computed tomography,CBCT)测量分析骨性Ⅱ类高角患者正畸治疗前后上下颌切牙区骨开窗、骨开裂发生率差异及牙槽骨改建特征。方法:选取骨性Ⅱ类高角患者46例,男18例,女28例,年龄(16.9±2.2岁),测量其正畸治疗前后上下颌切牙区牙槽骨形态特征,统计分析骨开窗、骨开裂转归及牙槽骨改建情况。结果:治疗前后骨开窗发生率分别为6.39%和3.00%,差异有统计学意义(P<0.05),骨开裂发生率分别为22.55%和23.91%,差异无统计学意义(P>0.05);治疗后切牙区舌腭侧骨开裂缺损深度增加,牙槽骨厚度和面积减少,差异均有统计学意义(P<0.05)。结论:骨性Ⅱ类高角患者正畸治疗后,上下颌切牙区唇侧牙槽骨增生修复,骨开窗、骨开裂状况改善;舌腭侧牙槽骨压迫吸收,牙槽骨厚度及面积减少,骨开裂发生率增加。

经枕外隆凸开窗取脑技术

目的 采用新的去枕骨取脑技术,提升取脑成功率。方法 在传统取脑技术的基础上锯开颅骨,以枕外隆凸为中心向下去除部分枕骨至枕骨大孔,暴露端脑、小脑、延髓后面等结构;然后清理小脑幕,切断延髓,在颅底切断相关脑神经,取出脑组织。结果 取出的脑组织端脑、小脑及脑干结构完整,脑沟内血管清晰,视交叉、嗅束、椎-基底动脉等较完整。结论 经枕外隆凸开窗取脑技术可有效保护脑标本的完整,提高取脑成功率,对于中枢神经系统实验教学及完善人脑组织资源库具有重要意义。

开窗减压术治疗口腔颌面部囊肿的临床效果分析

目的分析在口腔颌面部囊肿治疗中应用开窗减压术的临床效果。方法选取60例口腔颌面部囊肿患者,根据治疗方式不同分为参比组和分析组,每组30例。参比组应用囊肿刮除术治疗,分析组应用开窗减压术治疗。比较两组患者手术指标、囊腔缩小情况、并发症发生情况、临床疗效。结果分析组手术时间(57.32±13.21)min、住院时间(6.20±1.04)d均短于分析组的(81.21±12.21)min、(8.91±1.31)d,术中出血量(102.52±14.27)ml少于参比组的(151.52±17.21)ml,术后视觉模拟评分法(VAS)评分(3.37±0.53)分低于参比组的(5.56±0.60)分,有统计学差异(P<0.05)。分析组患者术后囊腔缩小率(83.20±8.21)%、囊腔缩小体积(51.23±4.21)mm^(3)、术后囊腔密度(0.52±0.14)g/m^(3)均高于参比组的(62.23±7.63)%、(36.62±3.97)mm^(3)、(0.33±0.11)g/m^(3),有统计学差异(P<0.05)。分析组并发症发生率3.33%低于参比组的20.00%,有统计学差异(χ^(2)=4.043,P=0.044<0.05)。分析组临床总有效率96.67%高于参比组的76.67%,有统计学差异(χ^(2)=5.192,P=0.023<0.05)。结论在口腔颌面部囊肿治疗中应用开窗减压术,可短时间内改善患者病情,促进症状转归,且较为安全,临床疗效更佳。

Laparoscopic fenestration vs open fenestration in patients with congenital hepatic cysts: A meta-analysis

AIM: To determine whether the outcomes of laparoscopic fenestration (LF) were superior to open fenestration (OF) for congenital liver cysts.METHODS: Comparative studies published between January 1991 and May 2010 on Medline (Ovid),Emsco,PubMed,Science Direct;Cochrane Reviews;CNKI;Chinese Biomedical Database,VIP and other electronic databases were searched.Randomized controlled trials (RCTs) and retrospective case-control studies on the management of congenital hepatic cysts were collected according to the pre-determined eligibility criteria to establish a literature database.Retrieval was ended in May 2010.Meta-analysis was performed using RevMan 5.0 software (Cochrane library).RESULTS: Nine retrospective case-control studies involving 657 patients,comparing LF with OF were included for the final pooled analysis.The meta-analysis results showed less operative time [mean difference (MD): -28.76,95% CI: -31.03 to 26.49,P < 0.00001];shorter hospital stay (MD: -3.35,95% CI: -4.46 to -2.24,P < 0.00001);less intraoperative blood loss (MD: -40.18,95% CI: -52.54 to -27.82,P < 0.00001);earlier return to regular diet (MD: -29.19,95% CI: -30.65 to -27.72,P < 0.00001) and activities after operation (MD: -21.85,95% CI: -31.18 to -12.51,P < 0.0001) in LF group;there was no significant difference between the two groups in postoperative complications (odds ratio: 0.99,95% CI: 0.41 to 2.38,P = 0.98) and cysts recurrence rates.CONCLUSION: The short-term outcomes of LF for patients with congenital hepatic cysts were superior to open approach,but its long-term outcomes should be verified by further RCTs and extended follow-up.

Long-term results of laparoscopic fenestration for patients with congenital liver cysts

BACKGROUND: The feasibility and immediate outcome of laparoscopic fenestration for patients with congenital liver cysts have been generally recognized. The aim of the present study was to assess the long-term results after laparoscopic fenestration. METHODS: A retrospective study was performed on 44 patients with congenital liver cysts who had undergone laparoscopic fenestration between June 1998 and December 2004. Among them, 30 were women and 14 men, aged 57 years on average (range 18-76 years). While 14 patients had solitary cysts, 20 had multiple cysts, and 10 had polycystic liver disease. The results of laparoscopic fenestration, including mortality, morbidity, mean postoperative hospital stay, and recurrences of cysts were evaluated. RESULTS: There was no perioperative death and the morbidity rate was 11% (5/44). All complications were treated conservatively. The mean postoperative hospital stay was 4 days. A mean follow-up of 57 months showed that the rates of cyst recurrence and symptom recurrence were 9% and 4.5%, respectively. CONCLUSION: Laparoscopic fenestration as a feasible and safe treatment procedure for patients with congenital liver cysts can yield very good long-term results.

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.

Treatment of polycystic liver disease with resection-fenestration and a new classification

AIM: To evaluate outcomes in patients with autosomal dominant polycyst liver disease (APLD) treated by combined hepatic resection and fenestration. A new classification was recommended to presume postoperative complications and long outcome of patients. METHODS: Twenty-one patients with APLD were treated by a combined hepatic resection and fenestration technique. All patients were reviewed retrospectively, and clinical symptoms, performance status and morbidity were recorded. A new classifi cation of APLD is recommended here. RESULTS: All patients were discharged when free of symptoms. The mean follow-up time was 55.7 mo and three patients had a recurrence of symptoms at 81, 68 and 43 mo after operation, respectively. The overall morbidity rate was 76.2%. Two patients with Type B-Ⅱ and Type B-Ⅰ developed biliary leakage. Four patients had severe ascites, including three with Type B-Ⅲ and one with Type B-Ⅱ, Nine patients had pleural effusion, including one with Type A-Ⅰ; one with Type B-Ⅰ; fi ve with Type B-Ⅱ; one with Type A-Ⅲ and one with Type B-Ⅲ. Three patients with Type B had recurrence of symptoms, while none with Type A had severe complications. CONCLUSION: Combined hepatic resection and fenestration is an acceptable procedure for treatment of APLD. According to our classifi cation, postoperative complications and long outcome can be predicted before surgery.

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.

Laparoscopic fenestration of multiple giant biliary mucinous cystadenomas of the liver

Biliary cystadenomas of the liver are rare, cystic neoplasms of the biliary ductal system usually occur in middle aged women. We report a case of synchronous multiple huge biliary mucinous cystadenomas with unique features. This is, according to our knowledge, the first report in the literature about three synchronously occurring hepatobiliary cystadenomas. Cystadenomas have a strong tendency to recur, particularly following incomplete excision, and a potential of malignant transformation. A therapeutic re-evaluation may be necessary when the diagnosis of hepatobiliary cystadenoma is made after the operation and an open liver resection should be considered.

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.

Endoscopic gastric fenestration of debriding pancreatic walled-off necrosis: A pilot study

BACKGROUND Endoscopic drainage of walled-off necrosis(WON) is still a challenge due to stentassociated problems. We explored endoscopic gastric fenestration(EGF) as an innovative alternative intervention.AIM To assess the feasibility, efficacy and safety of EGF for WON.METHODS Between March 2019 and March 2020, five patients with symptomatic WON in close contact with the stomach wall were treated by EGF. Endoscopic ultrasound(EUS) was used to select appropriate sites for gastric fenestration, which then proceeded layer by layer as in endoscopic submucosal dissection. Both the stomach muscularis propria and pseudocyst capsule were penetrated. Fenestrations were expanded up to 1.5-3 cm for drainage or subsequent necrosectomy.RESULTS EGF failed in Case 1 due to nonadherence of WON to the gastric wall. EGF was successfully implemented in the other four cases by further refinement of fenestration site selection according to computed tomography, endoscopy and EUS features. The average procedure time for EGF was 124 min(EUS assessment, 32.3 min;initial fenestration, 28.8 min;expanded fenestration, 33 min), and tended to decrease as experience gradually increased. The diameter of the fenestration site was 1.5-3 cm, beyond the caliber of a lumen-apposing metal stent(LAMS), to ensure effective drainage or subsequent necrosectomy. Fenestration sites showed surprising capacity for postoperative self-healing within 1-3 wk. No EGF-related complications were seen. WON disappeared within 3 wk after EGF. In Case 3, another separate WON, treated by endoscopic LAMS drainage, recurred within 4 d after LAMS removal due to stent-related hemorrhage, and resolved slowly over almost 3 mo. No recurrences were observed in the five patients.CONCLUSION EGF is an innovative and promising alternative intervention for WON adherent to the gastric wall. The challenge resides in the gauging of actual adherence and in selecting appropriate fenestration sites.

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.