Endovascular stent grafting versus open surgical repair of descending thoracic aortic aneurysms in low-risk patients: A multicenter comparative trial

OBJECTIVE

Results are presented from the first completed multicenter trial directed at gaining approval from the US Food and Drug Administration of endovascular versus open surgical repair of descending thoracic aortic aneurysms.

METHODS

Between September 1999 and May 2001, 140 patients with descending thoracic aneurysms were enrolled at 17 sites and evaluated for a Gore TAG Thoracic Endograft. An open surgical control cohort of 94 patients was identified by enrolling historical and concurrent subjects. Patients were assessed before treatment, at treatment, and at hospital discharge and returned for follow-up visits at 1 month, 6 months, and annually thereafter.

RESULTS

One hundred thirty-seven of 140 patients had successful implantation of the endograft. Perioperative mortality in the endograft versus open surgical control cohort was 2.1% (n = 3) versus 11.7% (n = 11, P < .001). Thirty-day analysis revealed a statistically significant lower incidence of the following complications in the endovascular cohort versus the surgical cohort: spinal cord ischemia (3% vs 14%), respiratory failure (4% vs 20%), and renal insufficiency (1% vs 13%). The endovascular group had a higher incidence of peripheral vascular complications (14% vs 4%). The mean lengths of intensive care unit stay (2.6 +/- 14.6 vs 5.2 +/- 7.2 days) and hospital stay (7.4 +/- 17.7 vs 14.4 +/- 12.8 days) were significantly shorter in the endovascular cohort. At 1 and 2 years' follow-up, the incidence of endoleaks was 6% and 9%, respectively. Through 2 years of follow-up, there were 3 reinterventions in the endograft cohort and none in the open surgical control cohort. Kaplan-Meier analysis revealed no difference in overall mortality at 2 years.

CONCLUSIONS

In this multicenter study early outcomes with descending aortic endovascular stent grafting were very encouraging when compared with those of a well-matched surgical cohort. However, at 2 years' follow-up, there is an incidence of endoleaks and reinterventions associated with endovascular versus open surgical repair. Continued vigilant surveillance of patients treated with an endograft is important.

Strategies to Manage Paraplegia Risk After Endovascular Stent Repair of Descending Thoracic Aortic Aneurysms

BACKGROUND

Paraplegia is a recognized complication after endovascular stent repair of descending thoracic aortic aneurysms. A management algorithm employing neurologic assessment, somatosensory evoked potential monitoring, arterial pressure augmentation, and cerebrospinal fluid drainage evolved to decrease the risk of postoperative paraplegia.

METHODS

Patients in thoracic aortic aneurysm stent trials from 1999 to 2004 were analyzed for paraplegic complications. Lower extremity strength was assessed after anesthesia and in the intensive care unit. A loss of lower extremity somatosensory evoked potential or lower extremity strength was treated emergently to maintain a mean arterial pressure 90 mmHg or greater and a cerebrospinal fluid pressure 10 mm Hg or less.

RESULTS

Seventy-five patients (male = 49, female = 26, age = 75 +/- 7.4 years) had descending thoracic aortic aneurysms repaired with endovascular stenting. Lumbar cerebrospinal fluid drainage (n = 23) and somatosensory evoked potential monitoring (n = 15) were performed selectively in patients with significant aneurysm extent or with prior abdominal aortic aneurysm repair (n = 17). Spinal cord ischemia occurred in 5 patients (6.6%); two had lower extremity somatosensory evoked potential loss after stent deployment and 4 developed delayed-onset paraplegia. Two had full recovery in response to arterial pressure augmentation alone. Two had full recovery and one had near-complete recovery in response to arterial pressure augmentation and cerebrospinal fluid drainage. Spinal cord ischemia was associated with retroperitoneal bleed (n = 1), prior abdominal aortic aneurysm repair (n = 2), iliac artery injury (n = 1), and atheroembolism (n = 1).

CONCLUSIONS

Early detection and intervention to augment spinal cord perfusion pressure was effective for decreasing the magnitude of injury or preventing permanent paraplegia from spinal cord ischemia after endovascular stent repair of descending thoracic aortic aneurysm. Routine somatosensory evoked potential monitoring, serial neurologic assessment, arterial pressure augmentation, and cerebrospinal fluid drainage may benefit patients at risk for paraplegia.

Society for Vascular Surgery (SVS) and Society of Thoracic Surgeons (STS) Reporting Standards for Type B Aortic Dissections

This Society for Vascular Surgery/Society of Thoracic Surgeons (SVS/STS) document illustrates and defines the overall nomenclature associated with type B aortic dissection. The contents describe a new classification system for practical use and reporting that includes the aortic arch. Chronicity of aortic dissection is also defined along with nomenclature in patients with prior aortic repair and other aortic pathologic processes, such as intramural hematoma and penetrating atherosclerotic ulcer. Complicated vs uncomplicated dissections are clearly defined with a new high-risk grouping that will undoubtedly grow in reporting and controversy. Follow-up criteria are also discussed with nomenclature for false lumen status in addition to measurement criteria and definitions of aortic remodeling. Overall, the document provides a facile framework of language that will allow more granular discussions and reporting of aortic dissection in the future.

Association of Mortality and Acute Aortic Events With Ascending Aortic Aneurysm: A Systematic Review and Meta-analysis

IMPORTANCE

The natural history of ascending aortic aneurysm (AsAA) is currently not well characterized.

OBJECTIVE

To summarize and analyze existing literature on the natural history of AsAA.

DATA SOURCES

A search of Ovid MEDLINE (January 1, 1946, to May 31, 2017) and Embase (January 1, 1974, to May 31, 2017) was conducted.

STUDY SELECTION

Studies including patients with AsAA were considered for inclusion; studies were excluded if they considered AsAA, arch, and descending thoracic aneurysm as 1 entity or only included descending aneurysms, patients with heritable or genetic-related aneurysms, patients with replaced bicuspid aortic valves, patients with acute aortic syndrome, or those with mean age less than 16 years. Two independent reviewers identified 20 studies from 7198 unique studies screened.

DATA EXTRACTION AND SYNTHESIS

Data extraction was performed according to the Meta-analysis of Observational Studies in Epidemiology (MOOSE) reporting guideline; 2 reviewers independently extracted the relevant data. Summary effect measures of the primary outcomes were obtained by logarithmically pooling the data with an inverse variance-weighted random-effects model. Metaregression was performed to assess the relationship between initial aneurysm size, etiology, and the primary outcomes.

MAIN OUTCOMES AND MEASURES

The primary composite outcome was incidence of all-cause mortality, aortic dissection, and aortic rupture. Secondary outcomes were growth rate, incidence of proximal aortic dissection or rupture, elective ascending aortic repair, and all-cause mortality.

RESULTS

Twenty studies consisting of 8800 patients (mean [SD] age, 57.75 [9.47] years; 6653 [75.6%] male) with a total follow-up time of 31 823 patient-years were included. The mean AsAA size at enrollment was 42.6 mm (range, 35.5-56.0 mm). The combined effect estimate of annual aneurysm growth rate was 0.61 mm/y (95% CI, 0.23-0.99 mm/y). The pooled incidence of elective aortic surgery was 13.82% (95% CI, 6.45%-21.41%) over a median (interquartile range) follow-up of 4.2 (2.9-15.0) years. The linearized mortality rate was 1.99% per patient-year (95% CI, 0.83%-3.15% per patient-year), and the linearized rate of the composite outcome of all-cause mortality, aortic dissection, and aortic rupture was 2.16% per patient-year (95% CI, 0.79%-3.55% per patient year). There was no significant relationship between year of study completion and the initial aneurysm size and primary outcomes.

CONCLUSIONS AND RELEVANCE

The growth rate of AsAA is slow and has implications for the interval of imaging follow-up. The data on the risk of dissection, rupture, and death of ascending aortic aneurysm are limited. A randomized clinical trial may be required to understand the benefit of surgical intervention compared with surveillance for patients with moderately dilated ascending aorta.

Perioperative Outcome in Adults Undergoing Elective Deep Hypothermic Circulatory Arrest With Retrograde Cerebral Perfusion in Proximal Aortic Arch Repair: Evaluation of Protocol-Based Care

OBJECTIVE

The purpose of this study was to describe perioperative outcome in adults undergoing elective proximal aortic arch repair with protocol-based deep hypothermic circulatory arrest (DHCA) with retrograde cerebral perfusion (RCP).

DESIGN

Retrospective and observational.

SETTING

Cardiothoracic operating rooms and intensive care unit.

PARTICIPANTS

Seventy-nine consecutive adults undergoing elective proximal aortic arch repair with DHCA (1999-2001).

INTERVENTIONS

None.

MAIN RESULTS

Average age of the patients was 64.9 years. Mean circulatory arrest time was 30.4 +/- 8.5 minutes. Perioperative mortality was 7.6%. Perioperative stroke incidence was 3.8%. Tracheal extubation was successful in 87.3% of patients within 24 hours of operation. Of the cohort, 80.8% were discharged from the intensive care unit within 72 hours of surgery. Median length of hospital stay was 7.4 days. Repeat mediastinal exploration because of bleeding occurred in 3.8% of patients. Although perioperative renal dysfunction (defined as >1.5-fold increase in plasma creatinine concentration) developed in 24.0% of patients, only 3.8% required dialysis.

CONCLUSIONS

The above parameters establish a baseline incidence for major perioperative complications in adults undergoing elective DHCA with RCP for elective proximal aortic arch repair. In approaching the open aortic arch for short periods of circulatory arrest, deep hypothermia with adjunctive RCP is safe and effective.

Long-term outcome of isolated coronary artery bypass surgery in patients with severe left ventricular dysfunction

BACKGROUND

Coronary artery bypass grafting (CABG) is indicated in patients with coronary artery disease and impaired ventricular function. However, earlier studies have suggested that prognosis of patients with severe left ventricular dysfunction is extremely poor. We used the APPROACH registry to derive contemporary estimates of prognosis associated with CABG for this high-risk patient population.

METHODS AND RESULTS

The study group consisted of 7841 patients who had isolated CABG in the province of Alberta, Canada between 1996 and 2001. Patients with markedly reduced left ventricular function (ejection fraction [EF] <30%, Lo EF, n =430) were compared with those with moderate reduction in ventricular function (EF 30% to 50%, Med EF, n =2581) and those with normal left ventricular function (EF >50%, normal [Nl] EF, n=4830). The operative mortality was higher in the patient group with Lo EF (4.6%) compared with Med EF and Nl EF groups (3.4% and 1.9%, respectively, P<0.001). At 5 years, survival was 77.7% for Lo EF patients compared with 85.5% and 91.2% for Med EF and Nl EF patients, respectively (P<0.001). After controlling for other independent variables, the adjusted hazard ratio for death was 1.98 (95% CI, 1.49 to 2.62) for Lo EF relative to Nl EF. The mortality rate at 1 year was significantly lower for Lo EF patients who underwent CABG than it was for nonrevascularized Lo EF patients (risk-adjusted odds ratio, 0.36; 95% CI, 0.24 to 0.55).

CONCLUSIONS

In the modern era of cardiac surgery, CABG can be performed in Lo EF cases with an acceptable perioperative mortality risk. Our estimate of 5-year survival in this high-risk group is better than previously reported in the literature from earlier periods.

Thoracic aortic stent grafting: Improving results with newer generation investigational devices

OBJECTIVE

Six years ago an endovascular program for repair of descending thoracic aneurysms was established at the University of Pennsylvania. We report on the hypothesis that results are improving with new stent design iterations and describe our experience and lessons learned.

METHODS

From April 1999 to March 2005, 99 patients with descending thoracic aneurysms underwent repair with a first or second-generation commercially produced endograft; 24 patients had an early-generation device, and 75 patients had a late-generation device. Each patient was enrolled as part of 3 distinct Phase I or Phase II Food and Drug Administration-approved clinical trials in accordance with strict inclusion and exclusion criteria.

RESULTS

Mean age was 73.1 years. Symptomatic aneurysms accounted for 42% of the cohort. Mean aneurysm size was 63.7 mm (range: 30-105 mm). Twenty percent of the patients underwent a subclavian carotid transposition or bypass preoperatively to obtain an adequate proximal landing zone. No procedures had to be aborted. In-hospital or 30-day mortality was 5.0%. The incidence of permanent spinal ischemia was 2%. Perioperative vascular complications requiring interposition graft, stent repair, or patch angioplasty occurred in 27% and seemed to be less frequent in the late-generation cohort than the early-generation cohort (22.7% vs 41.7%, respectively, P = .069). At the 30-day follow-up, 23 endoleaks were detected in 22 patients (14.7% in late-generation cohort vs 45.8% in early-generation cohort, P = .001). During the follow-up period, 3 new endoleaks were detected, 3 patients died of aortic rupture, and 10 patients underwent aneurysm-related reintervention. Kaplan-Meier estimated 1, 3, and 5-year survival was 84.5%, 70.5%, and 52.4%, respectively. Freedom from aneurysm-related event, defined as freedom from endoleak, aortic rupture, dissection, or any reintervention on the aorta, was 73%, 69%, and 64% at 1, 3, and 5 years, respectively.

CONCLUSION

Thoracic aortic stent grafting is a safe procedure in selected patients with the added benefit of a low incidence of paraplegia. However, there is an incidence of late complications and reinterventions. This risk requires further quantification and must be balanced against the benefits of a minimally invasive approach with low perioperative morbidity and mortality. Results are improving as technology evolves and our level of experience increases. Radiologic follow-up is mandatory.

Is There a Role for Biomechanical Engineering in Helping to Elucidate the Risk Profile of the Thoracic Aorta?

Clinical estimates of rupture and dissection risk of thoracic aortic aneurysms are based on nonsophisticated measurements of maximum diameter and growth rate. The use of aortic size alone may overlook the role that vessel heterogeneity plays in assessing the risk of catastrophic complications. Biomechanics may help provide a more nuanced approach to predict the behavior of thoracic aortic aneurysms. In this report, we review modeling studies with an emphasis on mechanical and fluid dynamics analyses. We identify open problems and highlight the future possibility of a multidisciplinary approach that includes biomechanics and imaging to evaluate the likelihood of rupture or dissection.

Valve-Sparing Root Replacement Versus Composite Valve Grafting in Aortic Root Dilation: A Meta-Analysis

BACKGROUND

Aortic valve-sparing operations theoretically have fewer stroke and bleeding complications but may increase late reoperation risk versus composite valve grafts.

METHODS

We meta-analyzed all studies comparing aortic valve-sparing (reimplantation and remodelling) and composite valve-grafting (bioprosthetic and mechanical) procedures. Early outcomes were all-cause mortality, reoperation for bleeding, myocardial infarction, and thromboembolism/stroke. Long-term outcomes included all-cause mortality, reintervention, bleeding, and thromboembolism/stroke. Studies exclusively investigating dissection or pediatric populations were excluded.

RESULTS

A total of 3794 patients who underwent composite valve grafting and 2424 who underwent aortic valve-sparing procedures were included from 9 adjusted and 17 unadjusted observational studies. Mean follow-up was 5.8 ± 3.0 years. Aortic valve sparing was not associated with any difference in early mortality, bleeding, myocardial infarction, or thromboembolic complications. Late mortality was significantly lower after valve sparing (incident risk ratio, 0.68; 95% confidence interval [CI], 0.54-0.87; P < .01). Late thromboembolism/stroke (incident rate ratio, 0.36; 95% CI, 0.22-0.60; P < .01) and bleeding (incident rate ratio, 0.21; 95% CI, 0.11-0.42; P < .01) risks were lower after valve sparing. Procedure type did not affect late reintervention.

CONCLUSIONS

Aortic valve sparing appears to be safe and associated with reduced late mortality, thromboembolism/stroke, and bleeding compared with composite valve grafting. Late durability is equivalent. Aortic valve sparing should be considered in patients with favorable aortic valve morphology.

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.

Thoracic aortic frontier: review of current applications and directions of thoracic endovascular aortic repair (TEVAR)

Thoracic endovascular aortic repair, a minimally invasive technique is replacing the maximally invasive gold standard of thoracotomy and replacement of the descending thoracic aorta. With experience, indications have expanded to encroach on the arch and even ascending aorta. This review highlights the current state of technology, discusses controversies, and takes the perspective of a forward-thinking review to describe novel, innovative techniques that might make the entire thoracic aorta amenable to minimally invasive repair.

Classification and outcomes of extended arch repair for acute Type A aortic dissection: a systematic review and meta-analysis

Objectives

Distal extent of repair in patients undergoing surgery for acute Type A aortic dissection (ATAAD) is controversial. Emerging hybrid techniques involving open and endovascular surgery have been reported in small numbers by select individual centres. A systematic review and meta-analysis was performed to investigate the outcomes following extended arch repair for ATAAD. A classification system is proposed of the different techniques to facilitate discussion and further investigation.

Methods

Using Ovid MEDLINE, 38 studies were identified reporting outcomes for 2140 patients. Studies were categorized into four groups on the basis of extent of surgical aortic resection and the method of descending thoracic aortic stent graft deployment; during circulatory arrest (frozen stented elephant trunk) or with normothermic perfusion and use of fluoroscopy (warm stent graft): (I) surgical total arch replacement, (II) total arch and frozen stented elephant trunk, (III) hemiarch and frozen stented elephant trunk and (IV) total arch and warm stent graft. Perioperative event rates were obtained for each of the four groups and the entire cohort using pooled summary estimates. Linearized rates of late mortality and reoperation were calculated.

Results

Overall pooled hospital mortality for extended arch techniques was 8.6% (95% CI 7.2-10.0). Pooled data categorized by surgical technique resulted in hospital mortality of 11.9% for total arch, 8.6% total arch and frozen stented elephant trunk, 6.3% hemiarch and frozen stented elephant trunk and 5.5% total arch and 'warm stent graft'. Overall incidence of stroke for the entire cohort was 5.7% (95% CI 3.6-8.2). Rate of spinal cord ischaemia was 2.0% (95% CI 1.2-3.0). Pooled linearized rate of late mortality was 1.66%/pt-yr (95% CI 1.34-2.07) with linearized rate of re-operation of 1.62%/pt-yr (95% CI 1.24-2.05).

Conclusions

Perioperative results of extended arch procedures are encouraging. Further follow-up is required to see if long-term complications are reduced with these emerging techniques. The proposed classification system will facilitate future comparison of short- and long-term results of different techniques of extended arch repair for ATAAD.

Acute aortic dissections with entry tear in the arch: A report from the International Registry of Acute Aortic Dissection

OBJECTIVE

To analyze presentation, management, and outcomes of acute aortic dissections with proximal entry tear in the arch.

METHODS

Patients enrolled in the International Registry of Acute Aortic Dissection and entry tear in the arch were classified into 2 groups: arch A (retrograde extension into the ascending aorta with or without antegrade extension) and arch B (only antegrade extension into the descending aorta or further distally). Presentation, management, and in-hospital outcomes of the 2 groups were compared.

RESULTS

The arch A (n = 228) and arch B (n = 140) groups were similar concerning the presence of any preoperative complication (68.4% vs 60.0%; P = .115), but the types of complication were different. Arch A presented more commonly with shock, neurologic complications, cardiac tamponade, and grade 3 or 4 aortic valve insufficiency and less frequently with refractory hypertension, visceral ischemia, extension of dissection, and aortic rupture. Management for both groups were open surgery (77.6% vs 18.6%; P < .001), endovascular treatment (3.5% vs 25.0%; P < .001), and medical management (16.2% vs 51.4%; P < .001). Overall in-hospital mortality was similar (16.7% vs 19.3%; P = .574), but mortality tended to be lower in the arch A group after open surgery (15.3% vs 30.8%; P = .090), and higher after endovascular (25.0% vs 14.3%; P = .597) or medical treatment (24.3% vs 13.9%; P = .191), although the differences were not significant.

CONCLUSIONS

Acute aortic dissection patients with primary entry tear in the arch are currently managed by a patient-specific approach. In choosing the management type of these patients, it may be advisable to stratify them based on retrograde or only antegrade extension of the dissection.

Management of the difficult left subclavian artery during aortic arch repair

Management of the left subclavian artery (SCA) during aortic arch surgery is associated with several challenges, including preserving distal perfusion, achieving hemostasis and preventing posterior circulation stroke and spinal cord injury. The most common challenge remains its deep position in the chest, often exacerbated by posterior and apical displacement from an arch aneurysm. We discuss several management options consisting of pre-, intra- and post-operative strategies and their respective advantages, disadvantages and clinical outcomes. A clinical algorithm is proposed to help guide decision-making in managing the difficult left SCA during aortic arch repair.

Cause of Death Following Surgery for Acute Type A Dissection: Evidence from the Canadian Thoracic Aortic Collaborative

BACKGROUND

Surgery confers the best chance of survival following acute Type A dissection (ATAD), yet perioperative mortality remains high. Although perioperative risk factors for mortality have been described, information on the actual causes of death is sparse. In this study, we aimed to characterize the inciting events causing death during surgical repair of ATAD.

METHODS

Nine centers participated in the study. We included all patients who died following surgical repair for ATAD between January 2007 and December 2013. An aortic surgeon at each site determined the primary cause of death from seven predetermined categories: cardiac, stroke, hemorrhage, other organ ischemia (peripheral, renal, or visceral), multiorgan failure, sepsis, or other causes. Additional characteristics and variables were analyzed to delineate potential modifiable factors for mortality.

RESULTS

Of the 692 surgeries for ATAD, there were 123 deaths (17.8% mortality rate). Mean age at death was 66 years. Events contributing to death were: cardiac (25%), stroke (22%), hemorrhage (21%), multiorgan failure (12%), other organ ischemia (11%), sepsis (4%), and other causes (5%). Neurologic injury at presentation was a predictor of stroke as the inciting cause of death (p = 0.04). Peripheral, renal, or visceral ischemia at presentation was highly predictive of death due to these presenting ischemic conditions (p = 0.004). We found no associations between cardiogenic shock, tamponade, or cardiopulmonary bypass duration and cardiac death.

CONCLUSION

Operative mortality for ATAD remains high in Canada. Nearly 70% of deaths arise from cardiac failure, stroke, or hemorrhage. Therefore, novel surgical, hybrid, and endovascular strategies should target these three areas.

Management of acute type A aortic dissection in the elderly: an analysis from IRAD

OBJECTIVES

We sought to examine management and outcomes of (Stanford) type A aortic dissection (TAAAD) in patients aged >70 years.

METHODS

All patients with TAAAD enrolled in the International Registry of Acute Aortic Dissection database (1996-2018) were studied (n = 5553). Patients were stratified by age and therapeutic strategy. Outcomes for octogenarians were compared with those for septuagenarians. Variables associated with in-hospital mortality were identified by multivariable logistic regression.

RESULTS

In-hospital mortality for all patients (all ages) was 19.7% (1167 deaths), 16.1% after surgical intervention vs 52.1% for medical management (P < 0.001). Of the study population, 1281 patients (21.6%) were aged 71-80 years and 475 (8.0%) were >80 years. Fewer octogenarians underwent surgery versus septuagenarians (68.1% vs 85.9%, P < 0.001). Overall mortality was higher for octogenarians versus septuagenarians (32.0% vs 25.6%, P = 0.008); however, surgical mortality was similar (25.1% vs 21.7%, P = 0.205). Postoperative complications were comparable between surgically managed cohorts, although reoperation for bleeding was more common in septuagenarians (8.1% vs 3.2%, P = 0.033). Kaplan-Meier 5-year survival was significantly superior after surgical repair in all age groups, including septuagenarians (57.0% vs 13.7%, P < 0.001) and octogenarians (35.5% vs 22.6%, P < 0.001).

CONCLUSIONS

When compared with septuagenarians, a smaller percentage of octogenarians undergo surgical repair for TAAAD, even though postoperative outcomes are similar. Age alone should not preclude consideration for surgery in appropriately selected patients with TAAAD.

Protocol for a randomised controlled trial for Treatment in Thoracic Aortic Aneurysm: Surgery versus Surveillance (TITAN: SvS)

INTRODUCTION

Ascending thoracic aortic aneurysm (ATAA) is an asymptomatic condition that can lead to catastrophic events of rupture or dissection. Current guidelines are based on limited retrospective data and recommend surgical intervention for ATAA with a diameter of greater or equal to 5.5 cm. Treatment in Thoracic Aortic Aneurysm: Surgery versus Surveillance is the first prospective, multicentre, randomised controlled trial that compares outcomes of patients undergoing early elective ascending aortic surgery to patients undergoing medical surveillance.

METHODS AND ANALYSIS

Patients between the ages of 18 and 80 with an asymptomatic ATAA between 5.0 cm and 5.4 cm in diameter are eligible for randomisation to early surgery or surveillance. Patients in the surgery group will be followed at 1 month after discharge, then annually for a minimum of 2 years and up to 5 years. Patients in the surveillance group will be followed annually from their index clinic visit for a minimum of 2 years and up to 5 years. The primary outcome is all-cause mortality at follow-up. A sample size of 618 subjects (309 in each group) will achieve an 80% power at a 0.047 significance level.

ETHICS AND DISSEMINATION

This study has received Ottawa Health Science Network Research Ethics Board approval (Protocol 20180007-01H), which was most recently updated on 25 November 2020. The Research Ethics Board have granted approval to the study at 14 participating institutions, including the Ottawa Health Science Network Research Ethics Board. On completion of data analysis, the result of the trial will be presented at national and international conferences, and published in relevant journals, regardless of the finding of the trial.

TRIAL REGISTRATION NUMBER

NCT03536312.

Midterm results of endovascular stent grafts in the proximal aortic arch (zone 0): an imaging perspective

BACKGROUND

Endovascular options to repair the arch and ascending aorta are rapidly evolving. Little is known about the durability of endovascular devices deployed at this location. This report describes a single-centre experience with the novel application of thoracic endovascular aortic repair (TEVAR) by examining clinical and radiological outcomes.

METHODS

A retrospective review was performed for a cohort of patients undergoing TEVAR of the arch or ascending aorta, or both, at a single centre from November 2008-July 2012.

RESULTS

Sixteen patients were included in the study, with mean imaging follow-up of 38 months (range, 15-72 months). Two complications at the proximal landing zone in the ascending aorta were identified: 1 endoleak and 1 infolding identified at 3 and 24 months postoperatively, respectively. Clinically, both these complications were attributed to the bird-beak configuration at the proximal landing zone site. At up to 72 months of follow-up, there were no cases of retrograde dissection of the native sinus of Valsalva. There were no cases of stent graft migration, graft fracture, open surgical reintervention for aortic pathologic conditions, or late mortality.

CONCLUSIONS

Early outcomes suggest that the current generation of thoracic aortic endografts can be placed in the complex anatomy of the ascending aorta and aortic arch without a high incidence of early graft fracture or migration. Future endeavors will need to focus on techniques to achieve optimal apposition with the curves of the ascending aorta. These findings are important as indications for endovascular aortic therapies expand to address proximal aortic pathologic conditions.