Endovascular stent grafting of the descending thoracic aorta after arch repair in acute type A dissection

An endovascular stent graft was successfully deployed to the primary entry site in the proximal descending thoracic aorta after total aortic arch replacement using the "elephant trunk" technique in acute type A aortic dissection. The residual false lumen of the descending aorta was thrombosed completely after stent grafting. The elephant trunk was feasible for a proximal landing zone for stent grafting of the descending aorta. Stent grafting in combination with aortic arch replacement was a safe and effective procedure, and may be an alternative choice in carefully selected patients with type A aortic dissection.     

Retrograde aortic dissection after a stent graft repair of a type B dissection: how to improve the endovascular technique

To date, endovascular repair of thoracic dissections is a reality, associated with acceptable morbidity and mortality. We present the case of a 72-year-old woman presenting a retrograde aortic dissection at the postoperative day 12, after an endovascular repair for a 60-mm thoracic dissecting aneurysm. Two years earlier, she had presented an uncomplicated thoracoabdominal type B aortic dissection between the isthmic aorta and the iliac bifurcation. Despite an acceptable blood pressure control, a 62-mm thoracic dissecting aneurysm was observed on the 24-month CT-scan. Due to a chronic obstructive pulmonary disease, we chose the endovascular approach to exclude the thoracic entry tear leading to the complete false lumen thrombosis around the endoprosthesis. However, the inferior part of the false lumen remained patent due to a second abdominal entry tear. The initial outcome was uneventful but the patient presented a sudden death syndrome twelve days after the endovascular repair. During the autopsy, we discovered an intrapericardial rupture of a retrograde dissection, starting at the level of the proximal bare spring of the endoprosthesis. We discuss some important technical details to improve the safety, and to reduce the risk of immediate or delayed complications.     

Endoluminal stent-graft placement in patients with acute aortic dissection type B

Objectives: This study was performed to evaluate the feasibility, safety and effectiveness of endovascular stent-grafting in treating Stanford type B acute aortic dissection. We describe our first clinical experiences and initial results with stent-grafting across the primary entry tear in patients with acute aortic dissection type B. Methods: Between March 2000 and August 2001, nine patients with acute type B dissection were treated endoluminally by stent-graft implantation. There were seven male and two female patients with a mean age of 63 years (between 48 and 85 years). In all nine patients aortic dissection was diagnosed by multislice computed tomography (CT) angiography. All nine patients had a maximal aortic diameter of 5.5 cm or more and recurrent pain, one patient showed hemoptysis. This patient with signs of a contained rupture was treated under emergency condition, the eight remaining patients were in hemodynamic stabile condition at the time of intervention. The GORE^® Excluder stent-graft system was used in eight patients (mean 1.8 stents/patient) and the TALENT^® stent-graft system in one patient, which were introduced transfemorally. Results: The primary entry tear could be sealed successfully in all nine patients. Complete thrombosis of the false thoracic aortic lumen was obtained in two patients, in the remaining seven patients the false lumen was obliterated in the area of the thoracic aorta but perfused via re-entries in the abdominal region. No severe intraoperative complications occurred. One patient developed bilateral incomplete paraplegia with motor and sensory deficits affecting completely the right leg and partially the left leg, 14 h after intervention. A cerebrospinal fluid drainage was initiated by inserting a lumbar catheter. All nine patients, including the patient with the transient paraplegia, could be discharged from the hospital in excellent condition and without remaining neurologic deficits. Control CT scans showed a reduction of the false lumen from 2.34±0.58 to 0.7±0.44 cm and an increase of the true lumen from 1.56±0.5 to 4.10±0.6 cm in the thoracic aortic region. Mean ICU stay was 1.8 days, mean postoperative hospital stay was 7.6 days. Conclusions: Stent-grafting of acute type B dissections may represent a very effective and promising new method by closure of the primary entry tear, thereby minimizing the risk of rupture of the thoracic aorta and optimizing distal perfusion by decompression of the true lumen.     

Transluminal placement of endovascular stent-grafts for the treatment of type A aortic dissection with an entry tear in the descending thoracic aorta

PURPOSE: The current therapy for type A aortic dissection is ascending aortic replacement. Operative mortality and morbidity rates have been markedly improved because of recent advances in surgical techniques and anesthesiology. However, type A aortic dissection with an entry tear in the descending thoracic aorta is still a surgical challenge because of the need for extensive aortic replacement. METHODS: Ten patients with type A aortic dissection were treated with endovascular stent-grafts. The false lumen of the ascending aorta was patent in five patients, and it was thrombosed in the other five patients. The entry tears were located in the descending thoracic aorta in all cases. Seven patients had acute dissection, and three patients had subacute dissection. Four patients had pericardial effusion. Stent-grafts were fabricated from expanded polytetrafluoroethylene and Z-stents. RESULTS: Entry closure was achieved in all patients. Complete thrombosis of the false lumen of the ascending aorta was observed after stent-grafting in all patients. A second stent-graft was required in two patients to obtain complete thrombosis of the false lumen of the descending thoracic aorta. No procedure-related complications were observed, with the exception of a minor stroke in one patient. During a mean follow-up period of 20 months, no aortic rupture or aneurysm formation was noted in either the ascending or descending thoracic aorta, and all patients were alive and doing well. The abdominal aortic aneurysm enlarged after stent-grafting in one patient, and this was treated by closing the fenestrations of the abdominal aorta with stent-grafts. CONCLUSION: Stent-graft repair of aortic dissection with an entry tear in the descending thoracic aorta is a safe and effective method and may be an alternative to surgical graft replacement in highly selected patients.     

B型主动脉夹层98例报告

目的探讨B型主动脉夹层的治疗效果,急、慢性主动脉夹层的治疗措施。方法 2001年7月～2011年6月98例B型主动脉夹层(胸主动脉夹层96例,腹主动脉夹层2例;急性主动脉夹层89例,慢性9例)行胸主动脉腔内修复术(thoracic endovascular aortic repair,TEVAR)83例,外科手术修复1例,保守治疗10例,术前夹层动脉瘤突然破裂死亡4例。采用直型带膜支架修复80例,分支带膜支架修复3例。杂交手术7例,先行右腋动脉-左腋动脉人工血管旁路移植5例,行左颈动脉-左锁骨下动脉人工血管旁路移植2例。保守治疗的10例中,4例经1周治疗痊愈。9例慢性主动脉夹层发现夹层不断扩大,采取腔内修复治疗。结果 83例腔内修复手术围手术期死亡2例,病死率2.4%(2/83),死亡原因:1例术后1周因心包填塞(尸检结果),1例为不明原因于术后第2天死亡,考虑为其他位置再次破裂所致;余81例术后恢复良好,无脑卒中发生。腔内手术发生Ⅰ型内漏14例(16.9%);81例出院时夹层内血栓形成69例,12例夹层中仍可见部分血流。保守治疗的10例,6例显示夹层内血栓形成,其余变化不大。84例随访2～121个月,平均36.5月,随访率91.3%(84/92),其中TEVAR随访75例,保守治疗随访8例,外科手术随访1例:1例腔内修复术后3个月胸降主动脉再次破裂死亡,2例Ⅰ型内漏存在,夹层不断扩大,再次放置带膜支架后消失,其余病例情况良好。结论急性B型主动脉夹层的治疗要积极,TEVAR为首选,可以取得比较好的疗效;慢性B型主动脉夹层应注意随访,必要时采用TEVAR治疗。     

腔内修复联合辅助技术治疗累及主动脉弓的Stanford B型夹层动脉瘤

目的 探讨主动脉腔内修复手术联合辅助技术治疗累及主动脉弓部的Stanford B型主动脉夹层动脉瘤.方法 分析腔内治疗累及主动脉弓部,破口邻近左锁骨下动脉或位于其近端的46例StanfordB型主动脉夹层动脉瘤的临床资料.腔内封堵左锁骨下动脉43例;PDA封堵器封堵左锁骨下动脉6例次;颈部动脉搭桥术9例次;“烟囱”技术重建左颈总动脉8例次;“开窗”技术封堵夹层破口,同时保留主动脉弓部所有分支动脉1例次.结果 患者术后均存活,随访时间(25±16)个月.未发生严重神经系统并发症.10例发生左锁骨下动脉Ⅱ型内漏,其中6例通过PDA封堵器隔绝,2例保守治疗后自愈;9例发生左上肢缺血症状,其中8例行保守治疗,另1例症状严重,行颈部动脉搭桥术重建左锁骨下动脉.随访中,所有人工血管和分支动脉支架均保持通畅,降主动脉真腔直径显著扩大,假腔直径逐渐缩小.结论 对累及主动脉弓部,破口邻近左锁骨下动脉或位于其近端的StanfordB型主动脉夹层,腔内治疗联合PDA封堵器、颈部动脉搭桥术、“烟囱”技术或“开窗”技术是安全有效的治疗方法.     

Aortic arch replacement with covered stent-graft as elephant trunk for a type A acute aortic dissection

We report a case of aortic arch replacement with a covered stent-graft as an "elephant trunk". A 54-year-old woman was diagnosed with Stanford type A aortic dissection. The initial intimal tear was located in the distal aortic arch. Under deep hypothermic circulatory arrest and retrograde cerebral perfusion, the distal end of the arch graft, which was turned inside out and reinforced with a Z-stent, was inserted into the distal true lumen as an "elephant trunk". Distal anastomosis was performed between the aortic wall and the inverted external graft. Graft replacement of the aortic arch and ascending aorta was followed by proximal arch grafting. Coronary artery bypass grafting to RCA was performed concomitantly. The postoperative course was uneventful, and the distal false lumen became thrombosed. This procedure is effective for reliable distal anastomosis and prevention of blood leakage into the distal false lumen.     

Endograft exclusion of the false lumen restores local hemodynamics in a model of type B aortic dissection

ObjectiveEndovascular intervention in uncomplicated type B dissection has not been shown conclusively to confer benefit on patients. The hemodynamic effect of primary entry tear coverage is not known. Endovascular stent grafts were deployed in a model of aortic dissection with multiple fenestrations to study these effects. It is hypothesized that endograft deployment will lead to restoration of parabolic true lumen flow as well as elimination of false lumen flow and transluminal jets and vortices locally while maintaining distal false lumen canalization.MethodsThoracic stent grafts were placed in silicone models of aortic dissection with a compliant and mobile intimal flap and installed in a flow loop. Pulsatile fluid flow was established with a custom positive displacement pump, and the models were imaged by four-dimensional flow magnetic resonance imaging. Full flow fields were acquired in the models, and velocities were extracted to calculate flow rates, reverse flow indices, and oscillatory shear index, the last two of which are measures of stagnant and disturbed flows.ResultsComplete obliteration of the false lumen was achieved in grafted aorta, with normal parabolic flow profiles in the true lumen (maximal velocity, 30.4 ± 8.4 cm/s). A blind false lumen pouch was created distal to this with low-velocity (5.8 ± 2.7 cm/s) and highly reversed (27.9% ± 13.9% reverse flow index) flows. In distal free false lumen segments, flows were comparable to ungrafted conditions with maximal velocities on the order of 7.0 ± 2.1 cm/s. Visualization studies revealed forward flow in these regions with left-handed vortices from true to false lumen. Shear calculations in free false lumen regions demonstrated reduced oscillatory shear index.ConclusionsPer the initial hypothesis, endovascular grafting improved true lumen hemodynamics in the grafted region. Just distally, a prothrombotic flow regimen was noted in the false lumen, yet free false lumen distal to this remained canalized. Clinically, this suggests a need for advancing endovascular intervention beyond sole entry tear coverage to prevent further false lumen canalization through uncovered fenestrations.     

Stanford B型主动脉夹层远端破口的初步临床探讨

目的 探索性提出Stanford B型主动脉夹层远端破口的腔内修复原则.方法 新疆维吾尔自治区人民医院血管外科2013年1月-2015年1月收治的101例Stanford B型主动脉夹层患者,按照不同的处理原则将患者分为两组:(1)序贯处理组57例:采取由近至远的原则腔内修复主动脉破口(如不处理内脏动脉处破口,亦不处理其远端破口);(2)非序贯处理组44例:不按照由近至远的原则腔内修复主动脉破口(不处理累及内脏动脉破口,其余远端破口行腔内修复).分别对两组患者术后腹腔干处主动脉径直径增长率、不适主诉发病率、假腔血栓化发病率进行统计分析.结果 两组患者术后腹腔干处主动脉直径增长率有明显差异(P＜0.05),序贯组低于非序贯组;不适主诉发病率及假腔血栓化比例均可见明显差异(P＜0.05),序贯组优于非序贯组.结论 经过初步临床探讨,我们得出在处理Stanford B型主动脉夹层远端破口时,序贯处理优于非序贯处理.     

Utility of Intraoperative Transesophageal Echocardiography during Endovascular Stent-graft Repair of Acute Thoracic Aortic Dissection

This study was undertaken to evaluate the utility and efficacy of intraoperative transesophageal echocardiography (TEE) in the endovascular management of patients with acute type B aortic dissection. Twelve consecutive patients with acute type B aortic dissection underwent elective endoluminal stent-graft repair in the operating room under angiographic and TEE guidance. The follow-up protocol included spiral CT scanning before discharge from the hospital to assess thrombosis exclusion of the aortic false lumen, perfusion of branch vessels, and the absence of perigraft leak. No complications related to the use of TEE were encountered. TEE clearly demonstated the presence and extent of the dissection flap in all patients. After the procedure a persistent perigraft leak or residual flow into the false lumen was diagnosed by TEE in 6 patients, whereas intraoperative angiography visualized only 3 cases. Postoperative CT scan confirmed these findings. One patient died 2 months later by aortic rupture secondary to a persistent perigraft leak not treated (8.3% mortality). No postoperative paraplegia or visceral ischaemia were registered, although an asymptomatic occlusion of left subclavian artery was observed. TEE monitoring detects perigraft leakage, identifies the entry tear, and accurately demonstrates sealing of the false lumen. TEE is essential in our practice as an adjuvant to fluoroscopy to achieve optimal results during endovascular stent-graft repair of acute thoracic aortic dissection.     

Endovascular treatment of arch and proximal thoracic aortic lesions

OBJECTIVE: To analyze at one institution the endovascular treatment for aortic arch and proximal thoracic aortic lesions, categorize open arch reconstruction, and make preliminary recommendations based on pathology (dissection vs aneurysm), and anatomical extent of disease. METHODS: A retrospective review of aortic arch and descending thoracic aortic lesions managed with endovascular treatment between June 2002 and June 2007. RESULTS: Thirty-four patients received endovascular repair for aortic dissection (n = 28) and aneurysm (n = 6). Open supra-aortic transposition or debranching of the great vessels was performed in 14 cases of dissection (50%) and six cases (100%) of aneurysm. In 14 dissections, the entry tear was located in the distal aortic arch, enabling the left subclavian artery to be sealed without reconstruction. The procedures were successful in 33 patients (97.1%); one intraoperative death occurred. Type I endoleaks were found intraoperatively in eight cases. After management with balloon angioplasty and by extending the stent implantation, the endoleaks resolved in four cases and decreased in four cases. One patient with Stanford type A dissection died from an unknown cause 3 months after treatment. The overall survival rate was 94.1% (32/34), and all bypass grafts remained patent during the follow-up period. CONCLUSIONS: Endovascular stent grafting is a safe and effective method for the treatment of aortic arch lesions. Transposition of the supra-aortic great vessels can be effectively combined with endovascular stent grafting to ensure both cerebral blood supply and enough landing area for the stent graft.     

Total arch replacement with elephant trunk procedure for retrograde dissection

BACKGROUND: The surgical management of type A dissection with the intimal tear in the descending aorta--retrograde dissection--has some challenging aspects because the standard approach through a median sternotomy for ascending aortic dissection is difficult in these cases in which the intimal tear is located in the descending aorta. METHODS: From January 1995 to December 2001, 12 (8.6%) consecutive patients aged 40 to 71 years underwent total arch replacement with an elephant trunk procedure through a median sternotomy for retrograde dissection of the ascending aorta (acute: 10, chronic: 2) among 139 patients with type A dissection. The intimal tear was located in the descending aorta in all patients. Dissection extended proximally to the aortic root in 7 patients and to the ascending aorta in 5, and extended distally to the abdominal aorta in 4 and to the common iliac artery in 8. RESULTS: Hospital mortality occurred in 1 patient (8%) owing to multiple organ failure after malperfusion of the renal arteries. Postoperatively the false lumen in the descending aorta was closed in all patients who survived but the false lumen in the abdominal aorta was patent in 9. The thoracic and abdominal aorta had slight dilatation in 2 patients. CONCLUSIONS: These data suggest that total arch replacement with an elephant trunk procedure through a median sternomy should be recommended in patients with type A dissection and the intimal tear in the descending aorta. This procedure induces thrombosis of the remaining false lumen in the distal aorta postoperatively.     

裂口位于主动脉弓远端Stanford A型主动脉夹层的腔内修复

目的总结腔内修复术治疗裂口位于主动脉弓远端Stanford A型主动脉夹层的临床经验。方法2001年1月至2006年6月在中山大学附属第一医院血管外科通过股动脉入路行主动脉腔内修复术,对21例内膜撕裂口位于主动脉弓远端和近端降主动脉的Stanford A型主动脉夹层进行血管腔内治疗,根据椎动脉造影确定是否重建左锁骨下动脉。结果全组21例中,急性夹层13例,慢性夹层8例,均接受了血管腔内带膜支架修复术,手术成功率100%。17例同时封闭了左锁骨下动脉,其中4例行左锁骨下动脉重建。4例发生内漏,1例术后发生脑梗死。平均随访22.3个月(6~65个月),所有病例均存活。假腔内完全血栓形成12例,部分血栓形成9例。结论主动脉腔内修复术治疗内膜撕裂口位于主动脉弓远端和近端降主动脉的Stanford A型主动脉夹层是有效和安全的,具有微创、成功率高和并发症少等特点。     

Adequate size of elephant trunk in the procedure of total arch replacement for acute aortic dissection

Total aortic arch replacement using the 'elephant trunk (ET)' procedure has commonly been applied to acute aortic dissection, but enlargement of a residual false lumen of the descending thoracic aorta sometimes occurs. We performed endovascular stent-grafting to close the entry as the second operation and obtained successful outcomes. From April 1997 to January 2004, we performed the modified ET procedure for acute aortic dissection in 29 patients and evaluated postoperative changes of the false lumen. In many cases of the residual false lumen, kinks and wrinkles were observed at the site of the ET grafts in the descending aorta. An adequate length of ET would be about 8 cm long to prevent kinking, and a diameter about 20 mm to prevent wrinkles.     

Aortic dissection with branch vessel occlusion: percutaneous treatment with fenestration and stenting

Aortic dissection involves a tear in the intimal and medial layers of the aortic wall. Early surgical treatment of this condition can be fraught with complications especially when the procedure to be performed involves treatment of renal and visceral vessels. Additionally, patients with this problem can have severe compromise of the flow to branches or the entire aortic distribution. Methods of endovascular therapy for these problems limit the surgical stress and often can be performed in less time than surgical revascularization might require. The use of endovascular stenting to improve vessel perfusion and fenestration of the dissection membrane to decrease pressure within the false lumen can be performed to relieve ischemic vascular beds and potentially decrease the risk of aneurysmal dilatation of the aorta. The increasing use of these techniques may allow stabilization of these patients before open repair of more proximal aortic dissection or a combination of therapy with endovascular stent grafting techniques.     

Open surgical intervention to recurrent aortic dissection after endovascular stent grafting

We report the case of a 49-year-old man who received open-heart surgery for recurrent aortic dissection after endovascular stent grafting. Stent grafting had been successfully performed in the acute phase. Recurrent dissection became obvious 5 months later, and at the same time, aneurysmal change was detected between the left subclavian artery and the proximal end of the stent graft. We employed a “Y arch” surgical procedure and “elephant trunk” technique to treat, and the entry tear was completely sealed and the aneurysm was excluded by elephant trunk segment. We believe that this approach could be a new option for treatment for complicated aortic aneurysms.     

Endovascular treatment of type B thoracic aortic dissections

PURPOSE: To evaluate the initial experience of endovascular repair of aortic dissections from a single center. MATERIALS AND METHODS: From June 1999 to March 2002, endovascular stent grafting was performed in 20 high-risk patients (16 to 80 years). Eighteen patients had a type B dissection (14 acute and 4 chronic). Two patients had chronic type A dissection. Preoperative work-up included CT and MRI to evaluate the extent of the dissection, the relation to the left subclavian artery, the size of false and true lumen, and branch complications. RESULTS: Stent-graft deployment was technically successful in all cases. None was converted to open repair. Three patients died within 30 days, i.e., a 15% mortality rate. Four patients (20%) had a perioperative stroke. Paraplegia was observed in one case. No migration of the stent grafts or endoleaks was observed during the mean follow-up period of 13 months. In all but two patient thrombosis of the false lumen was noted. CONCLUSIONS: Endovascular treatment of thoracic dissections is feasible. Early results are encouraging. While endovascular repair with stent-grafts is progressing rapidly as a viable strategy for aortic dissections in selected patients careful investigations must continue to focus on its safety. Randomized controlled trials are urgently needed.     

Decision-making in type-B dissection: current evidence and future perspectives

Aortic dissection is a devastating cardiovascular condition with an incidence of 3,5:100 000. It is classified according to anatomic extent, mechanism of lesion, duration from index event and course (uncomplicated vs. complicated). Intramural hematoma and penetrating aortic ulcers share many of the features of classic dissections, but tend to occur in older patients with advanced atherosclerosis. In uncomplicated type-B dissection, conservative treatment with tight blood pressure and heart rate control is safe and effective. Early stent-graft implantation may, however, result in more favorable aortic remodeling and reduced late complications. For acute complicated cases intervention is usually required. Stent-graft coverage of the entry tear frequently resolves malperfusion, but the role of the false lumen in organ perfusion must be assessed and endovascular revascularization performed if necessary. In chronic type-B dissections, coverage of the entry tear likely results in continued pressurization of the false lumen due to rigidity of the dissecting membrane and distal fenestrations. Better understanding of the different disease mechanisms involved, imaging advances and introduction of dedicated stent-grafts are expected to further improve patient outcomes in the future. Primary and secondary pharmacological prevention, stricter follow-up protocols and screening of family members may also prove valuable. Better patient selection will allow preventive treatment with low morbidity for those at higher risk of complications.     

Aortic dissection originating from an aberrant right subclavian artery

A 47-year-old male patient presented with aortic dissection originating from an aberrant right subclavian artery. Intraoperative arteriography showed an anomaly of the aortic arch including a common carotid trunk and an aberrant right subclavian artery. An intimal tear was located in the aberrant right subclavian artery. Dissection retrogradely involved the aortic arch and then anterogradely involved the distal aorta. We treated the patient endovascularly with a Wallgraft endoprosthesis deployed in the aberrant right subclavian artery to seal the entry site. Follow-up computed tomography showed a satisfactory healing process with complete thrombosis in the proximal part of the false lumen.     

Delayed visceral malperfusion after Bentall procedure for type A acute aortic dissection

Rapid restoration of flow into the true lumen and obliteration of a false lumen is considered the optimal approach to treating malperfusion syndrome due to acute aortic dissection. However, organ malperfusion can occasionally persist after proximal aortic graft replacement despite redirecting blood flow into the true lumen. A 35-year old man underwent the modified Bentall procedure for Stanford type A acute aortic dissection without organ malperfusion. Ischaemia of the visceral and lower extremities developed on postoperative day 8. Enhanced computed tomography (CT) revealed a thrombus in the false lumen interfering with the true lumen above the celiac trunk. We immediately performed a left axillary-to-bilateral femoral artery bypass. The patient recovered uneventfully and was discharged on postoperative day 28. Although organ malperfusion persisting after proximal aortic graft replacement despite redirecting blood flow into the true lumen is rare, close observation remains imperative after central repair of type A dissection.