3D Stereoscopic Visualization of Fenestrated Stent Grafts

The purpose of this study was to present a technique of stereoscopic visualization in the evaluation of patients with abdominal aortic aneurysm treated with fenestrated stent grafts compared with conventional 2D visualizations. Two patients with abdominal aortic aneurysm undergoing fenestrated stent grafting were selected for inclusion in the study. Conventional 2D views including axial, multiplanar reformation, maximum-intensity projection, and volume rendering and 3D stereoscopic visualizations were assessed by two experienced reviewers independently with regard to the treatment outcomes of fenestrated repair. Interobserver agreement was assessed with Kendall’s W statistic. Multiplanar reformation and maximum-intensity projection visualizations were scored the highest in the evaluation of parameters related to the fenestrated stent grafting, while 3D stereoscopic visualization was scored as valuable in the evaluation of appearance (any distortions) of the fenestrated stent. Volume rendering was found to play a limited role in the follow-up of fenestrated stent grafting. 3D stereoscopic visualization adds additional information that assists endovascular specialists to identify any distortions of the fenestrated stents when compared with 2D visualizations.     

Initial experience of branched endovascular graft for abdominal aortic aneurysm with complex anatomy of proximal neck: planning and technical considerations

The purpose of this report was to demonstrate initial Japanese cases of abdominal aortic aneurysm (AAA) with complex anatomy of proximal neck treated using a Zenith fenestrated endograft with branched endovascular technique and to describe the device’s design and technical considerations. Planning and sizing of endografts were performed using high-resolution computed tomography on a three-dimensional workstation. Branched endograft technique combined with reinforced fenestrated device and balloon-expandable stent graft was used in two patients because of challenging morphology for the fenestrated device with a bare stent. Successful exclusion of the aneurysm sac was achieved in both patients with antegrade perfusion in incorporated visceral vessels. Endovascular repair using a fenestrated device with graft material incorporating the visceral arteries is feasible. The combination of the reinforced fenestration and the balloon-expandable stent graft can provide an adequate sealing effect for the compromised anatomy. Initial and midterm results are reported with further follow-up and patient accrual.     

Fenestrated Stent Graft Repair of Abdominal Aortic Aneurysm: Hemodynamic Analysis of the Effect of Fenestrated Stents on the Renal Arteries

Objective

We wanted to investigate the hemodynamic effect of fenestrated stents on the renal arteries with using a fluid structure interaction method.

Materials and Methods

Two representative patients who each had abdominal aortic aneurysm that was treated with fenestrated stent grafts were selected for the study. 3D realistic aorta models for the main artery branches and aneurysm were generated based on the multislice CT scans from two patients with different aortic geometries. The simulated fenestrated stents were designed and modelled based on the 3D intraluminal appearance, and these were placed inside the renal artery with an intra-aortic protrusion of 5.0-7.0 mm to reflect the actual patients'' treatment. The stent wire thickness was simulated with a diameter of 0.4 mm and hemodynamic analysis was performed at different cardiac cycles.

Results

Our results showed that the effect of the fenestrated stent wires on the renal blood flow was minimal because the flow velocity was not significantly affected when compared to that calculated at pre-stent graft implantation, and this was despite the presence of recirculation patterns at the proximal part of the renal arteries. The wall pressure was found to be significantly decreased after fenestration, yet no significant change of the wall shear stress was noticed at post-fenestration, although the wall shear stress was shown to decrease slightly at the proximal aneurysm necks.

Conclusion

Our analysis demonstrates that the hemodynamic effect of fenestrated renal stents on the renal arteries is insignificant. Further studies are needed to investigate the effect of different lengths of stent protrusion with variable stent thicknesses on the renal blood flow, and this is valuable for understanding the long-term outcomes of fenestrated repair.     

Endovascular stent graft repair of abdominal aortic aneurysms: Current status and future directions

Endovascular stent graft repair of abdominal aortic aneurysm (AAA) has undergone rapid developments since it was introduced in the early 1990s. Two main types of aortic stent grafts have been developed and are currently being used in clinical practice to deal with patients with complicated or unsuitable aneurysm necks, namely, suprarenal and fenestrated stent grafts. Helical computed tomography angiography has been widely recognized as the method of choice for both pre-operative planning and post-operative follow-up of endovascular repair (EVAR). In addition to 2D axial images, a number of 2D and 3D reconstructions are generated to provide additional information about imaging of the stent grafts in relation to the aortic aneurysm diameter and extent, encroachment of stent wires to the renal artery ostium and position of the fenestrated vessel stents. The purpose of this article is to provide an overview of applications of EVAR of AAA and diagnostic applications of 2D and 3D image visualizations in the assessment of treatment outcomes of EVAR. Interference of stent wires with renal blood flow from the hemodynamic point of view will also be discussed, and future directions explored.     

腹主动脉瘤腔内隔绝术术中及术后移植物相关流出道狭窄的认识和处理

目的：探讨腹主动脉瘤（AAA）腔内隔绝术（EVE）术中及术后移植物相关流出道狭窄的认识和处理。方法：回顾性分析我科1997年3月至2002年10月间施行AAA EVE术中8例出现流出道狭窄，术后出现流出道狭窄3例，均为放置分叉型移植物。狭窄多发生于分叉起始端（5例）。7例给予球囊扩张，2例置入金属支架，2例股股交叉转流术。结果：术后随访1个月-2个年，无下肢缺血表现。结论：对于AAA EVE术中及术后移植物相关流出道狭窄，要及时诊断，判明原因，根据原因采取不同的治疗方法。     

Antegrade in situ fenestration of aortic stent graft: in-vivo experiments using a pig model

Background Short proximal neck of an abdominal aortic aneurysm is associated with risk of treatment failure during abdominal aortic repair. Important side branches, such as renal arteries, cannot be covered without serious consequences. Purpose To test the feasibility of preoperative fenestration of abdominal aortic stent grafts with a re-entry catheter and steerable sheath to preserve the patency of renal arteries in an animal model. Material and Methods Three domestic pigs were anesthetised and a stent graft placed in the abdominal aorta, covering the renal arteries. An attempt was made to fenestrate the renal arteries through the prosthesis using the Outback re-entry catheter supported by the Channel Steerable sheath. The hole that was created was dilated and stented. The specimens were visually analyzed after sacrifice. Results In one pig, the graft material was successfully traversed and a guide wire advanced in the renal arteries. Due to insufficient guide wire support and a poor balloon profile, dilatation of the fenestration failed. In another pig, the procedure was technically successful, but a long warm ischemia time for the left kidney caused infarction. In the third experiment, the procedure had to be discontinued due to a technical failure of the Outback device. Conclusion Fenestration of a stent graft with a re-entry device through a steerable sheath is technically feasible in vivo. However, without further refinement of the instrumentation, the technique cannot be recommended in elective cases of abdominal aortic repair, but if the renal arteries are covered accidentally during endovascular treatment, the technique may be a valuable salvage option if surgical revascularization is not considered as an option.     

Three-year follow-up of fenestrated thoracoabdominal stent graft bridging an endovascular thoracic stent graft and a surgical abdominal aortic graft

This case report describes repair of a type I endoleak at the distal landing zone of a thoracic aortic stent graft by endovascular placement of a thoracoabdominal fenestrated stent graft (Cook, Brisbane, Australia). The fenestrated stent graft was interposed between a previous abdominal aortic aneurysm (AAA) Gelsoft tube graft (Sulzer Vascutek Ltd, Inchinnan, United Kingdom) and two overlapping Zenith thoracic endografts (Cook Inc, Bloomington, Indiana). Placement was made more complex because the distal thoracic endograft had rotated into a horizontal position. At 3-year clinical and computed tomography (CT) follow-up, continued clinical and radiologic success was shown with no further intervention required.     

经皮开窗术治疗主动脉夹层引起的缺血

目的 评价经皮开窗术治疗主动脉夹层引起的内脏及下肢缺血。方法 6例主动夹层并发内脏及下肢缺血患者行经皮开窗术，所有患者皆是Stanford B型夹层，累及的血管有肾动脉（3条）、肠系膜动脉（1条）和下肢动脉（6条）。4例行单纯经皮开窗术，1例行开窗及左肾动脉支架置入治疗，1例行开窗及腹主动脉和双侧髂总动脉支架置入治疗。1例患者于开窗后1个月行支架移植物复合体（stent—graft）腔内隔绝术。结果 所有6例患者血管重建均成功，其中4例缺血症状消失，2例明显减轻。随访4～12个月，平均7．6个月，1例患者术后3个月死于主动脉破裂出血，余5例仍存活。无严重的手术相关并发症。结论 经皮开窗术或经皮开窗结合支架置入是1种安全、有效的治疗主动脉夹层引起的内脏及下肢缺血的方法。     

Juxtarenal aortic aneurysm: endoluminal transfemoral repair?

Endoluminal transfermoral repair of an abdominal aortic aneurysm by a stent graft placement requires a segment of the nondilated infrarenal aorta of at least 15 mm long for safe stent graft attachment. The possibility of endoluminal treatment of a juxtarenal abdominal aortic aneurysm with partially covered spiral Z stent was assessed in experiment and in three clinical cases. In the experiment, the noncovered spiral Z stent was placed into the abdominal aorta, across the origins of renal arteries and mesenteric arteries, in six dogs. In the clinical cases, a partially covered stent graft was attached in 3 patients with the juxtarenal abdominal aortic aneurysm (of the group of 12 patients with abdominal aortic aneurysm). The stent grafts were attached with proximal uncovered parts across the origins of the renal arteries. In experiment, the renal artery occlusions or stenoses were not observed 36 months after stent placement, and in clinic 3 patients with the juxtarenal aortic aneurysm were successfully treated by stent graft placement. There were no signs of flow impairment into the renal arteries 14 months after stent graft implantation. This approach can possibly expand the indications for endoluminal grafting in the treatment of juxtarenal aortic aneurysms in patients who are at high risk for surgery.     

复合手术室智能移动三维导航技术在近肾型腹主动脉瘤腔内治疗中的应用效果评价

目的：探讨复合手术室术中智能移动三维导航技术在近肾型腹主动脉瘤腔内治疗中的应用价值。 方法：选取2016年2月-2018年6月在江苏省苏北人民医院复合手术室治疗的7例近肾型腹主动脉瘤患者,术中行数字减影血管造影三维成像（3D-DSA）后将3D重建图像和2D透视图像进行图像融合,标记肾动脉及其他重要血管分支。并对不同阶段不同体位的术中三维导航融合图像进行自动修正配准,根据手术需要,改善融合图像的血管、骨骼背景密度,提高叠加图像上血管可视化程度,精确指导支架释放,实现血管内治疗的准确导航。 结果：7例患者在3D图像导航下行血管腔内腹主动脉瘤修复术,导丝导管均成功导入靶血管内,单根靶血管导入时间3~22 min,造影剂用量150~180 ml。7例行血管腔内腹主动脉瘤修复术均手术成功,术后即刻造影提示分支血管显影通畅,无内漏。 结论：复合手术室三维导航技术可精准标记肾动脉及其他分支血管开口,方便术中靶血管定位超选,对近肾型腹主动脉瘤腔内治疗具有重要的指导作用。     

Endovascular Preservation of Segmental Arteries during Treatment of Thoracoabdominal Aortic Aneurysms with Fenestrated/Branched Stent Grafts: Feasibility and Outcomes

PurposeTo evaluate the technical success, feasibility, and outcomes of endovascular preservation of segmental arteries (SAs) during fenestrated/branched endovascular aortic repair (F/B-EVAR).Materials and MethodsA multicenter, retrospective study was conducted in consecutive patients treated with F/B-EVAR and a branch or fenestration for SA preservation. Eleven patients (median age, 57 years; range, 45–73 years; 7 men) were included.ResultsTwelve SAs were preserved. Stent grafts were custom made with fenestrations, branches, or a combination of both in 1, 2, and 5 patients, respectively. A t-Branch stent graft was used in 2 patients, and a physician-modified thoracic stent graft with a branch was used in 1 patient. Eight branches and 4 fenestrations were used for the preservation of 12 SAs. Four fenestrations and 1 branch for the SAs were not bridged and were left for perfusion of the corresponding SAs. Technical success was achieved in 10 of 11 (91%) patients. No early mortality occurred. Early morbidities included renal insufficiency without dialysis in 1 patient and partially delayed paraplegia in 1 patient. Before discharge, computed tomography angiography (CTA) showed patency of all the SAs. The median follow-up duration was 30 months (range, 10–88 months). Late death occurred in 1 patient. Two SAs were occluded in 1 patient with 2 unstented fenestrations, as determined using 1-year follow-up CTA. This patient did not develop spinal cord ischemia (SCI). Other SAs remained patent during follow-up. One patient with a type IIIc endoleak was treated by relining of bridging stents.ConclusionsEndovascular preservation of SAs with F/B-EVAR for thoracoabdominal aortic aneurysm is feasible and safe in select patients and may add to preventive measures for SCI.     

腹主动脉瘤腔内隔绝术后迟发型远端内漏Ⅱ期腔内治疗

目的：探讨腹主动脉瘤（AAA）腔内隔绝术EVE后迟发型远端内漏的Ⅱ期腔内治疗方法的价值。方法：为3例AAA EVE3年以后迟发型远端内漏患者进行了Ⅱ期延伸移植物置入治疗，2例经双侧动脉切开、两侧各置入1枚延伸移植物，1例经腹膜后径路和股动脉径路完成3枚延伸移植物置入。结果：3例均应用了贯穿导丝牵张技术，延伸移植物置入完成后均将内漏消除。结论：Vanguard支架-人造血管系统的结构特点可能是导致远期远端内漏的原因；延伸移植物是治疗的有效方法。导丝牵张技术有助于手术成功并节约手术时间。     

Short-term and Midterm Results of Fenestrated Anaconda Endograft in Patients with Previous Endovascular Aneurysm Repair

Purpose

To review short-term and midterm results of the fenestrated Anaconda stent graft in management of patients with pre-existing endovascular aortic stent graft and persistent type 1a endoleak.

腹主动脉复合动脉瘤的腔内隔绝术治疗

目的：讨论复合腹主动脉病变进行腔内隔绝术（EVE）的可行性。方法：1例腹主动脉并存真性、假性和夹层动脉瘤患者，经双侧股动脉切开、肱动脉切开引入贯穿导丝，利用导丝导向技术和牵张技术成功置入模块式支架-人造血管移植物，以隔绝瘤体。结果：腔内隔绝操作技术完全成功，3个瘤体同时被隔绝，未加用任何延伸移植，未出现内漏、移位等并发症，重建血流通畅。结论：本例为EVE扩大适应证提供了经验。     

Tuberculous Aneurysm of the Abdominal Aorta: Endovascular Repair Using Stent Grafts in Two Cases

Tuberculous aneurysm of the aorta is exceedingly rare. To date, the standard therapy for mycotic aneurysm of the abdominal aorta has been surgery involving in-situ graft placement or extra-anatomic bypass surgery followed by effective anti-tuberculous medication. Only recently has the use of a stent graft in the treatment of tuberculous aortic aneurysm been described in the literature. We report two cases in which a tuberculous aneurysm of the abdominal aorta was successfully repaired using endovascular stent grafts. One case involved is a 42-year-old woman with a large suprarenal abdominal aortic aneurysm and a right psoas abscess, and the other, a 41-year-old man in whom an abdominal aortic aneurysm ruptured during surgical drainage of a psoas abscess.     

“Squid-Capture” Modified In Situ Stent–Graft Fenestration Technique for Aortic Arch Aneurysm Repair

An 83-year-old female was found to have an fusiform aneurysm in the aortic arch. She was deemed to be a high surgical risk; therefore, endovascular stent–graft placement followed by revascularization of the brachiocephalic trunk using in situ stent–graft fenestration was considered. However, the safe application of fenestration was deemed difficult due to the tortuosity of the brachiocephalic artery. The patient was successfully treated with the aid of the “squid-capture” technique, which consists of deployment of the stent–graft in a snare wire loop that was advanced from the brachiocephalic artery and fenestration of the stent–graft with the support of the loop. A follow-up exam revealed complete sealing of the aneurysm without any complications. The squid-capture technique allows for the safe and secure puncture of the graft.     

裸支架在腹主动脉瘤腔内隔绝术后近端内漏治疗中的应用

目的：探讨应用裸支架治疗主动脉瘤腔内隔绝术后近端内漏的价值和安全性。方法：使用裸支架地治疗原发性内漏3例，继发性内漏1例。1例裸支架在肾动脉下固定。3例跨双侧肾动脉开口固定。结果：裸支架均成功置入，近端内漏完全消除，术后未观察到肾功能受损、裸支架移位和近端内漏复发等并发症。结论：使用裸支架法治疗近端内漏，是一种安全、有效、可行的选择。     

Endovascular Aneurysm Repair and Sealing (EVARS): A Useful Adjunct in Treating Challenging Morphology

An 81-year-old male with previous open abdominal aortic aneurysm repair presented with asymptomatic large pseudoaneurysms at both ends of an open surgical tube graft. Endovascular aneurysm sealing (EVAS) in combination with the iliac limbs of a standard endovascular aneurysm repair (EVAR) successfully excluded both pseudoaneurysms from circulation. We describe the combination of elements of EVAS and EVAR and have termed this endovascular aneurysm repair and sealing (EVARS). EVARS has the advantage of harnessing the benefits of endobag sealing in aortic necks unsuitable for standard EVAR whilst providing the security of accurate stent placement within short common iliac arteries. In conclusion, EVAS may be combined with standard endovascular iliac limbs and is a possible treatment option for pseudoaneurysm following open aneurysm repair.     

内支架置入术治疗胸腹主动脉瘤的临床评价

目的：探讨胸腹主动脉瘤的ESG治疗临床疗效。方法：对10例患者分别行CTA、MRA、DSA检查和ESG治疗，其中Stanford B型夹层动脉瘤6例，真性腹主动脉瘤2例，肾动脉开口以下腹主动脉瘤2例（行分体式支架），所有病例均采用带膜支架。结果：8例行一体式支架腔内隔绝术，2例行分体式支架腔内隔绝术，均获成功。顺利植入，术后造影提示动脉瘤消失．无内漏发生。患者症状完全消失，全部患者在随访期间均未出现术前症状，未见相关并发症。结论：应用ESG治疗胸腹主动脉瘤安全、有效、创伤小、术后恢复快，长期疗效尚待进一步观察。     

应用国产覆膜支架治疗Stanford B型主动脉夹层动脉瘤

目的:评价应用国产覆膜支架治疗B型主动脉夹层动脉瘤的安全性及临床疗效.方法:自2005 - 05～2009 - 12对38例Stanford B型主动脉夹层动脉瘤实施了腔内隔绝术.其中男29例,女9例;年龄(54±12)岁.经CT增强扫描或磁共振成像(MRJ)确诊.切开左或右股动脉置入覆膜支架,封堵胸主动脉破裂口,置入后造影检查证实疗效,随访行CT或MRI检查.结果:支架置入全部成功,术后即刻造影36例无内漏,2例见少量内漏.降主动脉及腹主动脉真腔均明显扩大,远端降主动脉及分支供血均有不同程度改善.住院期间及随访1年内无患者死亡,发生主动脉腔内隔绝术后综合征3例.结论:应用国产覆膜支架腔内隔绝治疗B型主动脉夹层动脉瘤是一种操作简便、安全、成功率高、并发症少,疗效可靠的介入方法.