Surgical Correction of Ascending Type A Thoracic Aortic Dissection: Simultaneous Endoluminal Exclusion of the Arch and Distal Aorta

Left carotid chimney and left subclavian artery laser fenestration for zone 1 thoracic endovascular aortic repair

Thoracic endovascular aortic repair has become an increasingly used option for treatment of descending thoracic aortic aneurysms and dissections. Pathology involving the proximal thoracic aorta is more complex and requires revascularization of the subclavian and carotid arteries. We report a case of an arch thoracic aortic pseudoaneurysm repaired via a complete endovascular approach using a left carotid chimney and left subclavian artery laser fenestration.

Alternative management of proximal aortic dissection: concept and application

Open surgery remains the mainstay of treatment for acute type A aortic dissection and should be offered to most patients. However, there are elderly patients in which surgical treatment may be deemed extremely high risk or futile. Endovascular treatment approaches have been applied to a small number of these patients and data are limited to case reports and small series. The application of endovascular therapies to ascending aorta is currently limited by anatomical and technical challenges posed by the dynamic motion of the ascending aorta and the proximity of vital structures to intended landing zones (aortic valve, coronary arteries, and supra-aortic branches) and lack of specially designed endografts to address these issues. While thoracic endovascular aortic repair (TEVAR) has replaced open aortic repair for a suitable lesion in distal aortic dissection, some selected patients with type A aortic dissection at high surgical may be candidates. Hence, there is potential because, in proximal (Stanford type A) dissections, 10–30% of patients are not accepted for surgery, and 30–50% are technically amenable for TEVAR. Recent experience has shown that carefully selected patients with favorable anatomical characteristics may be subject to endovascular stent-graft treatment as a last resort with mixed results. Technical improvement is necessary to offer. satisfactory endovascular options in non-surgical candidates.

Direct access of ascending aorta for endograft delivery in the descending thoracic aorta

First-line therapy for aneurysm, dissection, or rupture of the descending thoracic aorta is now by the endovascular approach. Retrograde insertion of the endograft, through access from the femoral arteries, is the preferred approach. This case presents a new, innovative technique for delivery of an endoprosthesis into the descending thoracic aorta when hostile anatomy prevents delivery from the femoral arteries, iliac arteries, or infrarenal abdominal aorta in a patient not suitable for open repair.

Total arch repair for acute type A aortic dissection with open placement of a modified triple-branched stent graft and the arch open technique

Background

In total arch repair with open placement of a triple-branched stent graft for acute type A aortic dissection, the diameters of the native arch vessels and the distances between 2 neighboring arch vessels did not always match the available sizes of the triple-branched stent grafts, and insertion of the triple-branched stent graft through the distal ascending aortic incision was not easy in some cases. To reduce those two problems, we modified the triple-branched stent graft and developed the arch open technique.

Methods and results

Total arch repair with open placement of a modified triple-branched stent graft and the arch open technique was performed in 25 consecutive patients with acute type A aortic dissection. There was 1 surgical death. Most survivors had an uneventful postoperative course. All implanted stents were in a good position and wide expansion, there was no space or blood flow surrounding the stent graft. Complete thrombus obliteration of the false lumen was found around the modified triple-branched stent graft in all survivors and at the diaphragmatic level in 20 of 24 patients.

Conclusions

The modified triple-branched stent graft could provide a good match with the different diameters of the native arch vessels and the various distances between 2 neighboring arch vessels, and it’s placement could become much easier by the arch open technique. Consequently, placement of a modified triple-branched stent graft could be easily used in most patients with acute type A aortic dissection for effective total arch repair.

Results of type II hybrid arch repair with zone 0 stent graft deployment for complex aortic arch pathology

OBJECTIVE

To review the early results of a less invasive, single-stage hybrid arch procedure involving replacement of the ascending aorta, arch debranching, and zone 0 antegrade stent graft deployment.

METHODS

Between May 2007 and January 2012, 20 patients with both acute and chronic aortic pathology were managed at 2 institutions with a type 2 hybrid arch procedure. Indications included diffuse atherosclerotic aneurysm, false lumen expansion of chronic aortic dissections, penetrating atherosclerotic ulcer, and acute type A dissection. Mean age was 67 ± 16.8 years with a mean European System for Cardiac Operative Risk Evaluation II score of 29.5 ± 19.4. Postoperative clinical and imaging follow-up was complete to a mean 18.5 ± 15.3 months.

RESULTS

Successful zone 0 stent graft deployment was achieved in all cases. There was 1 in-hospital mortality (5%). A second death occurred at 40 days postoperation. Other complications included a permanent neurologic deficit in 1 patient (5%), transient paraplegia in 4 patients (20%), and 3 patients had respiratory complications (15%). There were no cases of renal failure requiring dialysis. Stent-related complications were identified in 4 patients (20%), including 3 type I endoleaks, none of which were at zone 0. There was 1 type II endoleak and a case of stent infolding. Two patients required a second successful endografting procedure.

CONCLUSIONS

This single-stage hybrid arch procedure offers an alternative approach to complex diffuse aortic pathology involving the arch. Replacement of the ascending aorta provides a safe location for zone 0 stent graft deployment, eliminating complications of proximal deployment in a native diseased aorta.

Gore TAG®Thoracic Endoprosthesis: the first US FDA-approved thoracic endograft

Open surgical repair of thoracic aortic lesions carries a significant risk of complications, including death. Minimally invasive approaches, however, may improve outcomes. Clinical trials of the Gore TAG Thoracic Endoprosthesis device indicate that subjects receiving the graft are less likely to experience major adverse events, less intraprocedural blood loss, shorter intensive care unit and hospital stays, and reduced recovery times than surgical patients. The US FDA approved the device in March 2005. Since then, the device has been used widely, although a 0.30% rate of complications related to infolding or partial compression of the device prompted a 'Dear Doctor' letter in January 2006. This article profiles the TAG device and evaluates endografting technology in general.

Endovascular stent-graft treatment for Stanford type A aortic dissection

OBJECTIVE

The aim of the study is to summarise our experience of endovascular stent grafting for Stanford type A aortic dissection.

DESIGN

Retrospective analysis at single centre.

METHODS

From January 2001 to January 2009, we treated 45 cases of Stanford type A aortic dissection with endovascular stent grafting. The entry tear was located at the ascending aorta in 10 cases (DeBakey type I), the aortic arch in 14 cases and the distal aortic arch or proximal descending aorta in 21 cases in which the ascending aorta was also involved by the dissection.

RESULTS

The surgical success rate was 97.8% (44/45) and 30-day mortality rate was 6.7% (3/45). Type I endoleaks occurred in 10 cases: one patient died intra-operatively, four were successfully treated with ballooning, four were sealed with aortic cuffs and one case caused by left subclavian artery (LSA) reflux was sealed with an occluder. Average follow-up time was 35.5 ± 5.4 months. Up to the most recent review or death, 32 patients had complete thrombosis and 10 had partial thrombosis inside the false lumen. Two deaths occurred after 30-days postoperatively.

CONCLUSION

Endovascular stent-graft treatment is a minimally invasive and effective method to treat Stanford type A aortic dissection.

Endografts for thoracic aortic pathologies--uncontested benefits in patient care

Medical and surgical treatment of thoracic aortic pathologies have been associated with considerable morbidity and mortality. Conversely, thoracic aortic endografting is proving to be extremely useful for correcting a variety of lesions with few complications. Endovascular intervention avoids sternotomy or thoracotomy, chest tubes, respirators and general anesthesia, and blood loss is limited. Complications such as paraplegia, renal failure and cardiac and pulmonary difficulties are minimized; hospital and rehabilitation times are also reduced. Selection of patients on the basis of favorable anatomy and pathology for a specific device is critical to procedural success. In addition, hybrid procedures combining endovascular and surgical techniques may extend the uses of available devices. Branched and fenestrated grafts are now being developed and are more accessible in Europe and Australia for use in thorac-abdominal aneurysm exclusion; they may be used in the arch and proximal descending thoracic aorta. However, at present, grafting in these regions has been associated with a significant incidence of stroke.

The arch and beyond: bare stents in the ascending aorta

PURPOSE

To describe the management of complications from an unsuccessful hybrid repair of an aortic arch aneurysm.

CASE REPORT

A 63-year-old man with acute type B dissection and retrograde dissection into the aortic arch underwent emergent hybrid repair, with partial debranching (ascending aorta to left carotid artery bypass) and proximal stent-graft deployment. At 3 months, computed tomography (CT) showed stent-graft migration, causing a large type I endoleak; flow through the patent left subclavian artery (LSA) caused a large type II endoleak. At a second operation, a bilateral subclavian-to-carotid transposition was performed; the LSA was ligated and a Zenith TX2 thoracic endograft was deployed to seal the leak. Recurrent type I endoleak a year later prompted the final endovascular solution: total supra-aortic vessel debranching, proximal stent-graft deployment, and the unprecedented use of bare Z stents in the ascending aorta. CT at 18 months confirmed stable stent-graft position and no endoleak.

CONCLUSION

Based on this initial experience, bare Z stents can be used to enhance proximal aortic stent-graft fixation and accommodation within the aortic arch.

Article Commentary: Managing Dissections of the Thoracic Aorta

Thoracic aortic dissection is associated with substantial morbidity and mortality, and it requires timely and accurate diagnosis and treatment. Long-term antihypertensive therapy remains critical for the treatment of this disease. Surgical intervention, although still a formidable undertaking, has evolved to better address both acute and chronic dissection, and the results have improved. Basic and clinical research, as well as technological advances, have increased our understanding of this challenging disease state.

Technical tips for thoracic aortic endografting

Thoracic aortic endografting is proving to be extremely useful for correcting a variety of lesions with few complications. Endovascular intervention avoids sternotomy or thoracotomy, the use of chest tubes, respirators, and general anesthesia, and limits blood loss. Compared with traditional open surgery, complications such as paraplegia, renal failure, and cardiac and pulmonary difficulties are minimized; hospital and rehabilitation times are also reduced. Selection of patients on the basis of favorable anatomy and pathology for a specific device is critical to procedural success. In some cases, a retroperitoneal conduit may be useful. In addition, left carotid-subclavian bypass or a transposition of the left subclavian artery to the left common carotid artery may be necessary before endografting, and spinal cord fluid drainage may be important when there is potential for cord ischemia.

Role of interventional repair in the thoracic aorta

Endovascular treatment of chronic aneurysmatic diseases of the descending thoracic aorta has demonstrated encouraging peri-interventional mortality and morbidity and is accepted as a preferred strategy in experienced centers. The emergence of endovascular strategies for acute thoracic aortic pathologies is an even more exciting new territory for nonsurgical interventions considering the sobering results of open surgery. Although it is apparent that patients at high risk for open surgery will benefit from endovascular strategies, the exact role of stent-graft placement remains to be defined, as the community awaits solid long-term data and as devices and techniques continue to improve. While some indications and scenarios, such as acute type B dissection with associated malperfusion syndrome or imminent aortic rupture, have been shown to benefit from stent-graft treatment, others are less settled. The current paper discusses both the established and emerging indications, as well as technical and anatomical aspects of this fascinating therapeutic option.

Hybrid approach to complex thoracic aortic aneurysms in high-risk patients: surgical challenges and clinical outcomes

BACKGROUND

Endovascular therapy is a less invasive alternative treatment for high-risk patients with thoracic aortic aneurysms. However, this technology alone is often not applicable to complex aneurysmal morphology. The purpose of this study was to evaluate the utility of hybrid strategies in high-risk patients who are otherwise unsuitable for endovascular therapy alone.

METHODS

During an 18-month period, 31 high-risk patients (mean age, 69 years; range, 52-89 years) underwent combined open and endovascular approaches for complex aneurysms, including 16 patients with ascending and arch aneurysms and 15 patients with aneurysms involving visceral vessels. Among them, 11 patients had histories of aneurysm repairs. To overcome the anatomic limitations of endovascular repairs, various adjunctive surgical maneuvers were used, including aortic arch reconstruction in 3 patients, supra-aortic trunk debranching in 13 patients (including 8 patients who required aortas as inflow sources), and visceral vessel bypasses in 15 patients (including 10 patients who required bypasses to all 3 visceral branches). Additionally, carotid artery access was obtained in 1 patient, and iliac artery conduits were created in 12 patients.

RESULTS

Technical success was achieved in all patients. There was one perioperative death (3.2%) due to postoperative bleeding. Two patients (6.4%) had immediate type II endoleaks, which were resolved by the 1-month follow-up. Other procedure-related complications occurred in three patients (9.6%), including renal bypass thromboses in two patients and retroperitoneal hematoma, which was successfully managed conservatively, in one patient. During a mean follow-up of 16 months, two patients died of unrelated causes, whereas the remainder of patients were asymptomatic, without aneurysm enlargement.

CONCLUSIONS

Our study highlights how hybrid strategies incorporating surgical and endovascular approaches can be used successfully in treating patients with complex thoracic aortic aneurysms. This combined approach potentially expands the field of endovascular stent grafting and is an attractive solution for patients with poor cardiopulmonary reserves.