Endovascular repair of the descending aorta and the aortic arch with the Relay stent graft

Endovascular Repair of Penetrating Thoracic Aortic Ulcers Using Tubular Stent Grafts Versus Stent Grafts With a Proximal Scallop

PURPOSE

In penetrating aortic ulcers (PAUs), limited data support tubular thoracic endovascular aortic repair (TEVAR) as a viable treatment option. For treatment of more proximal PAUs, hybrid approaches and-more recently-scalloped TEVAR (scTEVAR) have been advocated. Outcomes of scTEVAR specifically for PAUs have not yet been reported. This study reports long-term outcomes for tubular and scTEVAR in PAUs and compares the safety profile in both cohorts regarding the significantly more proximal landing zone (LZ) for scTEVAR.

MATERIALS AND METHODS

This single-center retrospective cohort study includes all nonacute patients treated for complicated PAU with scTEVAR and tubular TEVAR. Patient and PAU characteristics as well as procedural success, complication and reintervention rates, and all-cause and aortic mortality were analyzed.

RESULTS

Of 212 TEVAR procedures reviewed, 21 patients with tubular TEVAR and 19 patients with scTEVAR were included. Patient and PAU characteristics were similar, and LZ was significantly more proximal in the scTEVAR cohort (p=0.0001), with similar number and types of supra-aortic revascularization procedures. Clinical success was reached in all 40 patients (100%), and reintervention rate was 2/21 (9.5%) and 1/19 (5.3%), respectively. Over the mean follow-up of 63 (TEVAR) and 53 (scTEVAR) months, clinical success was stable in all patients with one (abdominal) aortic-related mortality in the scTEVAR cohort.

CONCLUSION

Treatment of complicated PAUs with TEVAR as well as scTEVAR provides excellent and similar clinical success, stability of clinical success, and aortic survival with acceptable complication and reintervention rates. Scalloped TEVAR safely lengthens the proximal sealing zone to address more proximal pathologies.

CLINICAL IMPACT

Treatment of asymptomatic complicated penetrating aortic ulcers (PAUs) with thoracic endovascular aortic repair (TEVAR) provides excellent clinical success and acceptable complication and reintervention rates. More patients become amenable to endovascular treatment by including scalloped TEVAR (scTEVAR) as a means to safely lengthen the proximal sealing zone to address more proximal pathologies.

Learning Curve and Long-Term Outcomes of Thoracic Endovascular Repair With the Relay Stent-Graft

PURPOSE

To define the learning curve of a widely employed stent-graft for thoracic endovascular repair (TEVAR) by analyzing procedural variables and their impact on long-term outcomes.

MATERIALS AND METHODS

Standard TEVARs for each major aortic thoracic disease were included excluding procedures using thoracoabdominal, arch fenestrated/branched devices and/or chimneys. The primary outcome was the learning curve analysis using the cumulative sum chart method. The secondary outcomes, presented as early (Q1-Q2) versus latest (Q3-Q4) quartiles of experience, were 30-day major adverse events (MAEs); procedural details (additional maneuvers, operative and fluoroscopy time, and contrast volume); 30-day clinical success; endoleak; aorta-related reintervention; and overall and aorta-related survival.

RESULTS

Between November 2005 and September 2021, 220 consecutive TEVAR procedures involving the Relay endograft (Terumo Aortic, Sunrise, FL, USA) were performed and included in the present analysis. The mean follow-up was 4.5 ± 3.9 years. The learning curve was reached after 10 patients. Secondary outcomes improved significantly over experience. Thirty-day MAE occurrence was 14.5% versus 11.8% (p=0.550). Additional maneuvers (p=0.009), access-vessel additional maneuvers (p=0.010), operative time (p=0.004), Relay Plus (p=0.001), and implantation of multiple stent-grafts (p=0.034) were independent risk markers for MAEs. Operative time (125.9 ± 66.7 vs 86.7 ± 48.5 minutes, p<0.001), contrast volume (185.4 ± 112.8 vs 140.5 ± 88.2 mL, p=0.003), and fluoroscopy time (12.4 ± 12.7 vs 8.8 ± 7.5 minutes, p=0.017) decreased significantly. Late endoleak occurrence was 19.5% with a nonsignificant reduction (21.8% vs 17.3%, p=0.395). Fluoroscopy time (hazard ratio [HR]=1.0; 95% confidence interval [CI]=1.0-1.1; p=0.008), contrast volume (HR=1.0; 95% CI=1.0-1.1; p=0.018), and type III aortic arch (HR=3.3; 95% CI=1.7-6.4; p<0.001) were independent risk markers for endoleak. Fluoroscopy time (HR=1.0; 95% CI=1.0-1.1; p=0.032) and type III aortic arch (HR=3.6; 95% CI=1.7-7.4; p=0.001) confirmed their significant association in a multivariable analysis.

CONCLUSION

In a high-volume center with a consistent previous endovascular experience, the Relay graft presented satisfactory long-term results with a short learning curve supporting its reliability.

CLINICAL IMPACT

The manuscript addresses the understanding of how many TEVAR procedures with a currently implanted device have been required to reach the learning curve for an endovascular skilled center. Our TEVAR experience with the Relay stent-graft (Terumo Aortic) demonstrated that ten implantations were required to achieve the device-related learning curve. The fifteen-year analyzed period showed that intraoperative learning-related variables were associated with long-term clinical outcomes and both improved over time. The Relay stent-graft presented satisfactory long-term results along with a short learning curve in a high-volume endovascular center supporting its ongoing implantation.

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.

Midterm outcomes in patients undergoing endovascular repair of thoracic aortic aneurysms and penetrating atherosclerotic ulcers using the RelayPlus stent graft

BACKGROUND

The Relay Thoracic Stent-Graft with Plus Delivery System (RelayPlus; Terumo Aortic, Sunrise, Fla) was designed to handle the curvature and tortuosity of the thoracic aorta. It was approved by the Food and Drug Administration in 2012; the postapproval study was stopped early because of adequate safety and efficacy data, and no difference was identified in experienced vs first-time users of RelayPlus. The purpose of this study was to report real-world outcomes of patients with thoracic aortic aneurysms and penetrating atherosclerotic ulcers (PAUs) undergoing thoracic endovascular aortic repair (TEVAR) with RelayPlus.

METHODS

This is a prospective, multicenter, nonrandomized postapproval study that required the use of novice implanters in the United States. Primary and secondary end points included device-related adverse events (deployment failure, conversion to open repair, endoleaks, migration, rupture, and mortality) and major adverse events (stroke, paraplegia/paraparesis, renal failure, respiratory failure, and myocardial infarction), respectively. Continuous and categorical covariates were reported in means or medians and percentages, respectively. Kaplan-Meier survival estimates were used to report long-term TEVAR-related mortality, all-cause mortality, and reinterventions at 3 years.

RESULTS

A total of 45 patients with mean age (standard deviation [SD]) of 73.5 (±7.20) years were treated for descending thoracic fusiform aneurysm (56%) or saccular aneurysm/PAU (44%). The patients were predominantly white (80.0%) and male (68.9%). Mean (SD) proximal neck, distal neck, and lesion lengths were 38.2 (±37) mm, 42.1 (±28) mm, and 103.8 (±74) mm, respectively. Mean (SD) aneurysm, proximal neck, and distal neck diameters were 53.9 (±13) mm, 31.3 (±4) mm, and 31.7 (±6) mm, respectively. Technical success was 100%. TEVAR-related mortality at 30 days was 4.4%; two patients died postoperatively, one of shock and the second of bilateral hemispheric stroke. No patient in the study had any conversion to open repair or post-TEVAR rupture. Two patients experienced three major adverse events, which included stroke (2.2%), paraplegia (2.2%), and respiratory failure (2.2%) at 30 days. Three-year freedom from TEVAR-related mortality, all-cause mortality, and reinterventions was 95.6%, 84.0%, and 97.2%, respectively. There were two type I endoleaks at 3 years: one type IB associated with no migration or aneurysm sac increase and one type IA associated with caudal migration of proximal neck and expansion of the proximal aorta.

CONCLUSIONS

The RelayPlus postapproval study reported low operative mortality and morbidity and supported use of the device as a safe and effective thoracic aortic aneurysm and PAU endovascular treatment. Early midterm follow-up showed sustained freedom from TEVAR-related mortality in real-world practice. Follow-up continues to evaluate the durability of this endograft.

Overall survival and factors predicting long-term outcome after thoracic aortic endovascular repair

PURPOSES

To assess overall survival and to determine factors predicting outcome after thoracic endovascular aortic repair.

MATERIALS AND METHODS

A Retrospective analysis was performed on a cohort of 212 consecutive patients (165 men and 47 women; mean age 64 years) who underwent thoracic endovascular aortic repair in a tertiary referral center for aortic disease. Main indications were true thoracic aortic aneurysm (n = 58; 27.6%), traumatic aortic rupture (n = 33; 15.7%), anastomotic pseudoaneurysms (n = 23; 10.9%), chronic type B aortic dissection (n = 22; 10.5%), and symptomatic, acute type B dissection (n = 21; 10.0%). In 79 patients (37.3%), a hybrid procedure, including supra-aortic rerouting, was performed. Kaplan-Meier estimates were used for overall survival and Cox regression models were used for univariable analysis of the association between risk factors and survival.

RESULTS

Proximal landing zones were predominantly zone 3 (n = 66; 31.3%), zone 2 (n = 63; 29.9%), and zone 1 (n = 38; 18%). In-hospital mortality was n = 18 (8.5%). Overall survival was 79.6%, 65.9%, and 51.1% at 2, 5, and 10 years, respectively; better overall survival was shown for traumatic aortic rupture, anastomotic pseudoaneurysms, and chronic posttraumatic pseudoaneurysms (p < 0.05). Clinical risk factors influencing overall survival include prior coronary bypass surgery, atrial flutter, arterial hypertension, renal failure, chronic obstructive pulmonary disease, and associated abdominal aortic aneurysm (p < 0.05).

CONCLUSIONS

Thoracic endovascular aortic repair is an effective treatment option for various thoracic aortic diseases with highest survival rates for traumatic aortic rupture and anastomotic pseudoaneurysms. Several clinical parameters are identified as risk factors for overall survival.

A novel sax-stent method in treatment of ascending aorta and aortic arch aneurysms evaluated by finite element simulations

OBJECTIVES

A novel stent method to simplify treatment of proximal ascending aorta and aortic arch aneurysms was developed and investigated by finite element analysis. Therapy of ascending aortic and aortic arch aneurysms is difficult and challenging and is associated with various complications.

METHODS

A 55mm wide×120mm long stent was designed without the stent graft and the stent was deployed by an endovascular method in a virtual patient-specific aneurysm model. The stress-strain analysis and deployment characteristics were performed in a finite element analysis using the Abaqus software.

RESULTS

The stent, when embedded in the aortic wall, significantly reduced aortic wall stresses, while preserving the side coronary ostia and side branches in the aortic arch. When tissue growth was modeled computationally over the stent struts the wall stresses in aorta was reduced. This effect became more pronounced when increasing the thickness of the tissue growth. There were no abnormal stresses in the aorta, coronary ostium and at the origin of aortic branches. The stent reduced aneurysm expansion cause by hypertensive condition from 2mm without stenting to 1.3mm after stenting and embedding.

CONCLUSION

In summary, we uncovered a simple treatment method using a bare nitinol stent without stent graft in the treatment of the proximal aorta and aortic arch aneurysms, which could eventually replace the complex treatment methods for this disease.

TEVAR: Endovascular Repair of the Thoracic Aorta

The development of thoracic endovascular aortic repair (TEVAR) has allowed a minimally invasive approach for management of an array of thoracic aortic pathologies. Initially developed specifically for exclusion of thoracic aortic aneurysms, TEVAR is now used as an alternative to open surgery for a variety of disease pathologies due to the lower morbidity of this approach. Advances in endograft technology continue to broaden the applications of this technique.

Hybrid aortic arch repair

The successes of thoracic endovascular aortic repair (TEVAR) have spurned new approaches to addressing thoracic aortic pathologies. These hybrid techniques offer an alternative in patients with multi-segmental thoracic aortic pathologies which would have otherwise required a two-step arch replacement and open descending arch repair. The following article offers a clinical insight to the available hybrid approaches, such as rerouting of supra-aortic vessels. Unique complications to endovascular repairs, and technical risks and issues, are also presented along with management options and strategies to minimize such concerns.

Scalloped thoracic stent-graft for treatment of aortic arch aneurysms with unfavourable landing zones

Endovascular treatments are limited in cases of thoracic aortic aneurysms extending up or proximal to the origin of the left subclavian artery (LSCA). In such cases, the LSCA is usually either occluded or revascularised. We report our first experience of four patients who underwent thoracic aneursym treatment with new custom-made grafts with a scallop in situ for the LSCA. The graft is tailor made per case, and a re-enforced scallop is positioned proximally allowing for the stent to be deployed beyond the origin of the LSCA; the origin of the LSCA remains patent, thus negating the need for revascularisation of the head and neck vessels on the left. The stent contains markers for identifying the scallop and are located along the midline to ensure correct alignment. All of the patients who underwent this procedure had technical success with flow through the LSCA both immediately after stent deployment and on follow-up imaging. This new stent has further expanded endovascular treatment options for patients with thoracic aneurysms extending up to and beyond the LSCA, which can play a part in improving outcome and decreasing mortality rates because surgery for revascularization will not be needed.