Editor's Choice - Outcomes of Endovascular Repair Confined to the Ascending Thoracic Aorta: A Systematic Review and Meta-Analysis

OBJECTIVE

High risk, inoperable patients with ascending aortic disease are increasingly managed with thoracic endovascular aortic repair (TEVAR). The aim of this study was to assess the available literature on TEVAR confined to the ascending aorta (a-TEVAR), describing study and patient characteristics, procedural and stent graft details, and outcomes.

DATA SOURCES

This was a systematic review and meta-analysis. MEDLINE, Web of Science, and Scopus were systematically searched for eligible studies reporting on outcomes after a-TEVAR (PROSPERO ID: CRD42023440826). Eligible studies reported outcomes after a-TEVAR without adjunctive supra-aortic vessel treatment.

REVIEW METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement was followed. The ROBINS-I and Joanna Briggs Institute Critical Appraisal Checklist were used as quality assessment tools. A Grading of Recommendations Assessment, Development, and Evaluation (GRADE) evidence certainty analysis was performed for the main outcomes. The main outcome was death. A proportional meta-analysis was performed with a mean and 95% confidence interval (CI) for the main outcomes. All articles were included up to 1 January 2024.

RESULTS

Ninety four studies were included (19 cohort studies, 75 case reports or series), reporting on 259 patients (57.8% male). The mean age was 69.1 (95% CI 65.0 - 73.1) years and mean follow up 19.6 (95% CI 14.5 - 24.6) months. The most common comorbidity was prior cardiac or thoracic surgery (n = 191). The most frequent indications for a-TEVAR (52.1% urgent a-TEVAR) were type A aortic dissection (43.6%) and pseudoaneurysm (38.6%). The most commonly deployed stent grafts were Gore (44.5%), Cook (23.5%), and Medtronic (17.0%). The in hospital mortality rate was 7.3% (95% CI 4.7 - 11.2%), 30 day mortality rate 7.7% (95% CI 5.1 - 11.6%), and overall mortality rate 17.0% (95% CI 12.9 - 22.0%) during follow up. GRADE showed very low evidence certainty for all outcomes. Eighty eight complications were reported and there was a re-operation rate of 13.1% (95% CI 9.5 - 17.8%). In hospital and 30 day mortality rates for type A dissection were 12.4% (95% CI 7.5 - 19.7%) (n = 14) and 13.3% (95% CI 8.2 - 20.8%) (n = 15), respectively, and for pseudoaneurysm 4.0% (95% CI 1.6 - 9.8%) (n = 4) and 4.0% (95% CI 1.6 - 9.8) (n = 4), respectively.

CONCLUSION

Despite heterogeneous literature and very low GRADE evidence certainty, a-TEVAR seems technically feasible in high risk patients. In addition, there is need for a consensus on when and how to use a-TEVAR and a need for a specific endograft for use in the ascending aorta.

Endovascular Treatment of Type A Aortic Dissection: A Systematic Review and Meta-Analysis Using Reconstructed Time-to-Event Data

OBJECTIVE

The undisputed gold standard of treatment for type A aortic dissections (TAAD) is open surgery. Anecdotal reports have assessed thoracic endovascular aortic repair (TEVAR) as a last resort for highly selected candidates. The present study aims to evaluate endovascular outcomes in TAAD patients who are unsuitable for open surgery whilst having TEVAR-compatible aortic anatomy.

METHODS

A PRISMA-compliant systematic search of the PubMed, Scopus, and Cochrane databases was performed up to 19 May 2022. Time-to-event data were reconstructed using Kaplan-Meier curves from the source literature.

RESULTS

In 20 eligible studies, 311 patients underwent TEVAR for acute, subacute, or chronic TAAD. Mean age at the time of the operation was 60.70 ± 8.00 years and 75.48% (95% Confidence Interval [CI], 60.33-88.46%) of the included patients were males. Mean operative time was 169.40 ± 30.70 min. Overall, 0.44% (95% CI, 0.00-4.83%) of the cases were converted to salvage open surgery. Technical failure, stroke, and endoleaks occurred in 0.22%, 0.1%, and 8.52% of the cohort, respectively. Thirty-day postoperative complication rate was 7.08% (95% CI, 1.52-14.97%), whereas late complications developed in 16.89% (95% CI, 7.75-27.88%) of the patients. One-, three-, and five-year survival rates were estimated at 87.15%, 82.52% and 82.31%, respectively. Reintervention was required in 8.38% of the cohort over a mean follow-up of 32.40 ± 24.40 months.

CONCLUSIONS

TEVAR seems to be feasible in highly selected patients with TAAD who cannot tolerate open surgery. Overcoming technical limitations and acquiring long-term data are warranted to safely define the place of endovascular treatment in the armamentarium of TAAD repair.

Thoracic endovascular aortic repair of an anastomosis pseudoaneurysm after the Bentall procedure assisted by rapid ventricular pacing: A case report

Background

Although commonly used for the treatment of descending aortic dissection, endovascular repair is challenging for ascending aortic pseudoaneurysms. Rapid ventricular pacing (RVP), a method that temporarily impedes cardiac output by stopping ventricular activity, heralds potential benefits for thoracic endovascular aortic repair (TEVAR) during precision landing. Recently, we successfully treated an anastomosis pseudoaneurysm after the Bentall procedure using TEVAR assisted by RVP.

Case report

A 69-year-old male was admitted to our hospital with a ascending aortic anastomosis pseudoaneurysm. He had undergone a Bentall procedure and a coronary artery bypass grafting nine years prior. After extensive consultation, the decision was made to perform TEVAR with the assistance of RVP. After a covered stent graft was delivered to the precise location of the ascending aorta, RVP was performed at a frequency of 180 beats/min with a pacemaker. When a flattened arterial blood wave of <50 mmHg was observed, the stent graft was released precisely between the opening of the coronary graft and innominate artery. Angiography revealed the presence of an endoleak; therefore, a set of interlock coils were packed into the aneurysm. Subsequent angiography showed intact blood flow in the aorta, superior arch branches, and coronary graft vessels. The patient recovered uneventfully after the procedure. He was discharged six days later and was doing well at the eight-month follow-up.

Conclusion

The case indicates that TEVAR assisted by RVP is a promising combination for ascending aortic pseudoaneurysm in selected patients.

Endovascular repair of the ascending aorta: the last frontier

Different pathologies of the ascending aorta (AA), including aneurysms, acute and chronic dissections, and pseudoaneurysms, have been treated with open surgical repair with very good results, especially at aortic centers of excellence. There is, however, a subset of patients for whom open surgery is considered to pose high or prohibitive risk. These patients can benefit from a less invasive approach with catheters and wires, percutaneous techniques and stent grafts. However, the existing technology was developed to treat descending thoracic aortic pathologies; it is not approved for use in the AA by the US Food and Drug Administration (FDA). The devices used for the descending thoracic aorta (DTA) have certain size and design limitations that make their application to the AA cumbersome at times. As a result, custom-made endografts have been used to treat pathologies in the AA, although their use is feasible only in elective procedures. In addition, the AA has specific anatomic and physiologic characteristics that raise concerns about the long-term durability of the current technology. In this review, we outline the limitations, challenges and current status of endovascular technology to treat pathologies of the AA.

Endovascular Stent-Graft Repair of the Ascending Aorta: Assessment of a Specific Novel Stent-Graft Design in Phantom, Cadaveric, and Clinical Application

Purpose

To test a stent-graft specifically designed for the ascending aorta in phantom, cadaver, and clinical application, and to measure deployment accuracy to overcome limitations of existing devices.

Methods

A stent-graft has been designed with support wires to fixate the apices toward the inner curvature, thereby eliminating the forward movement of the proximal end which can happen with circumferential tip capture systems. The device was deployed in three aortic phantoms, and in four cadavers, deployment precision was measured. Subsequently, the device was implanted in a patient to exclude a pseudoaneurysm originating from the distal anastomosis after ascending aortic replacement.

Results

The stent-grafts were successfully deployed in all phantoms and cadavers. Deployment accuracy of the proximal end of the stent-graft was within 1 mm proximally and 14 mm distally to the intended landing zone on the inner curvature, and 2–8 mm distal to the intended landing zone on the outer curvature. In clinical application, the pseudoaneurysm could be successfully excluded without complications.

Conclusion

The novel stent-graft design promises accurate placement in the ascending aorta. The differential deployment of the apices at the inner and outer curvatures allows deployment perpendicular to the aortic axis.

Level of Evidence

No level of evidence.

Anesthetic Considerations in Endovascular Repair of the Ascending Aorta

Since the first endovascular aortic repair in 1990, endovascular devices and the indications for their use have significantly grown. Considerable progress has been made in endovascular devices and techniques, such that endovascular repair is now considered first-line treatment for patients with descending aortic disease. However, for patients with ascending aortic disease, open surgical repair with cardiopulmonary bypass and hypothermic cardiac arrest was the only option until recently. Although the outcomes for open surgical repair of the ascending aorta have improved over the years, approximately 30% of patients with an emergent surgical indication, such as type A aortic dissection, are considered to be too high risk for open repair. For these patients, endovascular repair of the ascending aorta offers a life-saving procedure. The ascending aorta is regarded as the final frontier for endovascular therapy. Endovascular repair of it has posed a formidable challenge thus far, due to its unique anatomy, hemodynamic forces, and lack of an appropriate stent-graft designed specifically for the ascending aorta. Although currently there are no comprehensive data from randomized clinical trials, there are several case series and case reports that have shown favorable outcomes. Improvements in available devices soon will drive an exponential increase in the number of patients undergoing endovascular ascending aortic repair. In this review, the authors discuss multiple aspects of endovascular ascending aortic repair including the unique surgical and anesthetic considerations, the devices used, and the available outcomes data, and future directions are also explored.

Endovascular ascending aortic repair in type A dissection: A systematic review

PURPOSE

Up to 10% of acute type A aortic dissection (TAAD) patients are deemed unfit for open surgical repair, exposing these patients to high mortality rates. In recent years, thoracic endovascular aortic repair has proven to be a promising alternative treatment modality in specific cases. This study presents a comprehensive overview of the current state of catheter-based interventions in the setting of primary TAAD.

METHODS

A literature search was conducted, using MEDLINE and PubMed databases according to PRISMA guidelines, updated until January 2020. Articles were selected if they reported on the endovascular repair of DeBakey Type I and II aortic dissections. The exclusion criteria were retrograde type A dissection, hybrid procedures, and combined outcome reporting of mixed aortic pathologies (e.g., pseudoaneurysm and intramural hematoma).

RESULTS

A total of 31 articles, out of which 19 were case reports and 12 case series, describing a total of 92 patients, were included. The median follow-up was 6 months for case reports and the average follow-up was 14 months for case series. Overall technical success was 95.6% and 30-day mortality of 9%. Stroke and early endoleak rates were 6% and 18%, respectively. Reintervention was required in 14 patients (15%).

CONCLUSION

This review not only demonstrates that endovascular repair in the setting of isolated TAAD is feasible with acceptable outcomes at short-term follow-up, but also underlines a lack of mid-late outcomes and reporting consistency. Studies with longer follow-up and careful consideration of patient selection are required before endovascular interventions can be widely introduced.