Thoracic Endovascular Aortic Repair in the Setting of Compromised Distal Landing Zones

Efficacy and Safety of Endovascular Fenestrated and Branched Grafts Versus Open Surgery in Thoracoabdominal Aortic Aneurysm Repair: An Updated Systematic Review, Meta-analysis, and Meta-regression

OBJECTIVE

To provide an updated systematic review and meta-analysis with meta-regression of efficacy and safety of fenestrated/branched endovascular repair of thoracoabdominal aortic aneurysms (TAAAs) compared with open repair.

BACKGROUND

Endovascular repair of TAAAs may be a promising alternative to open surgery by reducing invasiveness and expanding the eligible population, but evidence remains limited.

METHODS

We applied "Prepared Items for Systematic Reviews and Meta-analysis" guidelines to retrieve, quantitatively pool, and critically evaluate the efficacy and safety (including 30-day mortality, reintervention, spinal cord injury [SCI], and renal injury) of both approaches. Original studies were retrieved from PubMed, Embase, and Cochrane Library until April 20, 2022, excluding papers reporting <10 patients. Pooled proportions and means were determined using a random-effect model. Heterogeneity between studies was evaluated with I2 statistics.

RESULTS

Sixty-four studies met the predefined inclusion criteria. Endovascular cohort patients were older and had higher rates of comorbidities. Endovascular repair was associated with similar proportions of mortality (0.07, 95% confidence intervals [CI]: 0.06-0.08) compared with open repair (0.09, 95% CI: 0.08-0.12; P = 0.22), higher proportions of reintervention (0.19, 95% CI: 0.13-0.26 vs 0.06, 95% CI: 0.04-0.10; P < 0.01), similar proportions of transient SCI (0.07, 95% CI: 0.05-0.09 vs 0.06, 95% CI: 0.05-0.08; P = 0.28), lower proportions of permanent SCI (0.04, 95% CI: 0.03-0.05 vs 0.06, 95% CI: 0.05-0.07; P < 0.01), and renal injury (0.08, 95% CI: 0.06-0.10 vs 0.13, 95% CI: 0.09-0.17; P = 0.02). Results were affected by high heterogeneity and potential publication bias.

CONCLUSIONS

Despite these limitations and the lack of randomized trials, this meta-analysis suggests that endovascular TAAA repair could be a safer alternative to the open approach.

Midterm Outcomes of Primary and Secondary Use of an Endoanchor System for Thoracic and Abdominal Aortic Endovascular Aortic Repair

PURPOSE

To assess the safety, technical success, and midterm outcomes of endoanchor (Heli-FX, Medtronic, Santa Rosa, California) deployment in thoracic endovascular aortic repair (TEVAR) or abdominal endovascular aortic repair (EVAR).

MATERIALS AND METHODS

This single-institution, retrospective study of all endoanchor procedures was performed from February 1, 2017 to March 30, 2021. All procedures were performed percutaneously by interventional radiologists. Clinical information and outcome data were retrieved from electronic medical records. Fifty patients (14% females, n = 7; 86% males, n = 43; median age, 79 years [range, 56-93 years]) underwent Endoanchor procedures, with 349 Endoanchors implanted; 33 procedures were primary deployments (at initial stent deployment) and 17 were secondary deployments (previous stent deployment). For the primary group (4 TEVARs and 29 EVARs), indications were prophylactic (n = 30), hostile neck (n = 28), hostile distal landing zone (n = 2), and intraprocedural type 1a endoleaks (n = 3). For the secondary group (4 TEVARs and 13 EVARs), indications were graft migration (n = 8), seal zone expansion without proven endoleak (n = 7) (proximal [n = 4] or distal seal [n = 3]), and proven type 1a endoleak (n = 2).

RESULTS

Median number of endoanchors deployed per procedure was 7 (range, 3-10). Median time to deploy endoanchors was 22 minutes (range, 8-46 minutes). The technical success rate of Endoanchor was 99.7% (348/349). The 30-day mortality rate was 0%. The overall adverse event rate was 6% (n = 3). Reinterventions were performed in 12% of patients (n = 6). Median follow-up was 38 months (range, 2-71 months). Overall survival at 1 and 3 years was 95% and 85%, respectively. Overall freedom from type 1a endoleak at 1 and 3 years was 96% and 93%, respectively.

CONCLUSIONS

Endoanchor procedures are safe with excellent technical success rate and good midterm clinical outcomes.

How to treat type 1b endoleakage-extension, fEVAR, bEVAR, or open repair

Thoracic endovascular aneurysm repair has been well described in the literature as a treatment for a wide range of thoracic aortic pathologies. As with any intervention, there remains a risk of an unfavorable outcome, including endoleak, a term used to describe unexpected blood flow between the stent-graft and the wall of the excluded aneurysm. Endoleaks cause pressurized enlargement of the aneurysmal sac and may lead to catastrophic outcomes such as rupture and death. Type 1b endoleak represents a distal landing zone that is compromised by retrograde blood flow. Moreover, there is a lack of data on type 1b endoleaks and its management options. With the increase in emerging endovascular techniques and technologies, endoleaks are more frequent. However, the management of endoleaks is not standardized among different centers. The purpose of this article is to provide an overview of type 1b endoleaks after thoracic endovascular aneurysm repair, current management options, and our experience.

Severe Tortuosity of the Distal Descending Thoracic Aorta Affects the Accuracy of Distal Deployment During a Thoracic Endovascular Aortic Repair

PURPOSE

An accurate distal deployment is essential for successful thoracic endovascular aortic repair (TEVAR) of a paradiaphragmatic aortic aneurysm. This study aimed to investigate the anatomical and intraoperative factors that affect the accuracy of distal deployment during TEVAR.

METHODS

We conducted a retrospective review of preoperative and postoperative computed tomography scans of 426 patients undergoing TEVAR at our institution between October 2008 and May 2021, of which the stent-graft was attempted to be deployed just above the celiac axis or the superior mesenteric artery in 56 patients. Based on the anatomical factors related to the malposition (deployed >10 mm away from the target vessel) and the greater curve to the straight-line ratio (G/S ratio), the patients were categorized as severe tortuosity (n=21) and mild tortuosity (n=35) groups to compare the operative and clinical outcomes.

RESULT

Stent-graft malpositioning occurred in 21 cases. Among all anatomical variables, only the G/S ratio was significantly larger in the malpositioned cases (p=0.049). A cutoff G/S ratio value of 1.15 was determined using the receiver operating curve analysis. In the severe tortuosity group, the distal end of the stent-graft was significantly farther (median: 10.0 [interquartile range (IQR): 2.5-19.5] mm vs 3.0 [0-8.0] mm; p=0.015) from the target vessel, and the tilt angle of the stent-graft's distal edge was larger (median: 21.4 [IQR: 15.8-24.5] vs 9.5 [5.5-12.5] degree; p<0.01) than that in the mild tortuosity group. Both groups were comparable for the incidence of a primary type Ib endoleak (p=0.454), a secondary type Ib endoleak (p=1.0), and the rate of distal reintervention (p=0.276).

CONCLUSION

Severe tortuosity in the distal descending thoracic aorta is associated with a malpositioned and tilted distal end of the stent-graft.

CLINICAL IMPACT

Thoracic endovascular aortic repair (TEVAR) for paradiaphragmatic thoracic aortic aneurysms requires accurate distal landing. In this paper, a retrospective CT analysis revealed that the greater curve to the straight-line ratio (G/S ratio) was associated to affects the malposition of the stent graft, defined as being deployed more than 10 mm away from the target vessel. Further, a comparative analysis based on the G/S ratio demonstrated that severe aortic tortuosity was associated with a more distal and tilted deployment of the stent graft.

Clinical Validation of the Impact of Branch Stent Extension on Hemodynamics in ISF-TEVAR Involving LSA Reconstruction

Background

The study of hemodynamics regarding thoracic endovascular aortic repair (TEVAR) is helpful to improve the surgical efficacy.

Objective

Correlations between hemodynamic changes and branch stent extension length and interference factors for branch stent extension length of in situ fenestration TEVAR (ISF-TEVAR) involving the left subclavian artery (LSA) were evaluated.

Materials and Methods

This study retrospectively analyzed 196 patients with Stanford type B aortic dissection who received in situ laser fenestrated thoracic endovascular aortic repair with LSA fenestration from April 2014 to March 2021. Branch stent extension to the main stent graft was evaluated by the computed tomographic angiography (CTA). Hemodynamic change of LSA was defined as a 20 mmHg interbrachial systolic pressure difference. The factors affecting the extension of the branch stent were also evaluated.

Results

All patients underwent ISF-TEVAR with LSA fenestration, and there was no recurrence during the follow-up. The mean length of the branch stent extension was 10.37 ± 0.34 mm, which was used to divide the patients into long and short groups. Asymptomatic hemodynamic changes (defined as a 20 mmHg interbrachial systolic pressure difference) in LSA were observed in 61 patients undergoing ISF-TEVAR involving LSA fenestration. The Spearman correlation analysis showed extension length of a branch stent &gt;1.5 cm elevated the risk of hemodynamic changes.

Conclusion

Overall, we conclude that branch stent extension length &gt;1.5 cm induced LSA hemodynamic changes. Appropriate shortening of the stent extension length can improve the curative effect of ISF-TEVAR, especially when faced with a type II/III aortic arch and stent angles of &lt;30 degrees.

Mid-term outcomes of the use of endoanchors during thoracic endovascular aortic repair in multicentre analysis

Objective

To describe mid-term outcomes of the use of EndoAnchors as an adjunct for arch and thoracic endovascular aortic repair (TEVAR).

Methods

A retrospective multicentre series from nine centres using the Heli-FX EndoAnchor System (Medtronic Inc, Minneapolis, USA) at TEVAR over May 2014–May 2019 is presented. The study is registered at ClinicalTrials.gov with number NCT04100499. The primary outcome was freedom from Type I endoleak at EndoAnchors deployments; secondary outcomes included evaluation of aortic wall penetration (AWP) at first computed tomography scan, EndoAnchor-related issues and mortality.

Results

54 high-risk patients (35 males/19 females, age 73 ± 11 years) with arch, thoracic and thoracoabdominal aneurysmal disease (3 chronic post-dissection and one patch pseudoaneurysm), with a mean neck length 19.7 ± 6.6 mm that were treated with multiple hybrid and endovascular techniques were included. A total of 329 EndoAnchors were used with a mean of 6.1 ± 2.5 per patient. Overall adequate AWP was 86%, whereas arch (Ishimaru’s zones 0–2) deployments achieved 80.6% when compared to 87.3% in descending thoracic aorta (dTA); although there was no statistical significance. Freedom from type I endoleaks was 88% at 2 year follow-up, due to 4 type IA endoleaks, two of them successfully treated, one with conservative treatment due to complexity of repair and remaining patient died 1 year later due to endograft infection. There were reported five EndoAnchor-related issues; four losses and one renal stent-graft was crushed due to catheter deflection solved with balloon reinflation. None of the losses had clinical significance. Overall mortality is described for 7 (9.5%) patients, one of them aneurysm-related.

Conclusions

The adjunctive use of EndoAnchors in TEVAR and complex TEVAR procedures achieved acceptable outcomes at midterm in a high-risk series with hostile seal zones. Still, they should be still judiciously used as there is lack of data to suggest a more liberal use; therefore, the landing zone should not be compromised in favour of their use.

Preoperative Planning for EndoAnchor Use During Thoracic Endovascular Aortic Repair in the Distal Aortic Arch

PURPOSE

To describe steps related to intraoperative C-arm orientations that can be taken during preoperative planning of thoracic stent-graft repair to facilitate the deployment of EndoAnchors in the distal aortic arch.

TECHNIQUE

Previous experience from transcatheter aortic valve implantation (TAVI) may be helpful in addressing issues with C-arm orientation. In TAVI, preoperative computed tomography (CT) images are routinely obtained to generate a patient-specific curve that represents a virtually complete rotation of the C-arm perpendicular to the annulus. The curve clearly demonstrates that each adjustment in cranial or caudal view needs parallax correction in the left or right anterior oblique direction to remain perpendicular, and vice versa. This experience can be translated to the preoperative planning of EndoAnchor use in the aortic arch. By placing markers along the circumference of the proximal landing zone of the preoperative CT scan, the required C-arm orientations can be determined for each marker.

CONCLUSION

Determining the optimal C-arm orientation during preoperative planning will facilitate successful EndoAnchor deployment and may contribute to improved durability of endovascular repair in hostile necks in the aortic arch.