Prospective Multicenter Study of the Low-Profile Relay Stent-Graft in Patients with Thoracic Aortic Disease: The Regeneration Study

Comparison of bare and nonbare stent grafts during thoracic endovascular aneurysm repair of the aortic arch

OBJECTIVE

We compared the outcomes of patients treated with nonbare stents (NBS) and proximal bare stents (PBS) endografts with a proximal landing zone in the aortic arch during thoracic endovascular aortic repair (TEVAR).

METHODS

We conducted a retrospective cohort, observational, multicenter study that included 361 consecutive TEVAR procedures undertaken between November 2005 and December 2021. TEVAR patients with both BS and NBS Relay stent graft configurations with proximal landing in zones 1, 2, or 3 were enrolled. Preoperative anamnestic and morphological data, clinical outcomes, and aortic modifications 30 days after surgery and at the latest follow-up available were collected. The primary outcome was freedom from proximal endoleak (type IA) comparing the two configurations. Total and detailed endoleak rates, clinical and technical success, intraoperative additional maneuvers, major adverse events, and reinterventions were secondary outcomes.

RESULTS

The median follow-up was 4.9 (interquartile range, 2.0-8.1) years. No statistically significant difference between NBS and PBS patients concerning 30-day major adverse events, retrograde aortic dissection, disabling stroke, or late type IA endoleak (10.8% vs 7.8%; P = .597). Aneurysmal disease (P = .026), PLZ diameter of >34 mm (P = .026), aortic tortuosity index of >1.4 (P = .008), type III aortic arch (P = .068), and PLZ thrombus (P = .014) identified as risk factors by univariate Cox regression analysis. PLZ thrombus was the only type IA endoleak risk factor at multivariate Cox regression (P = .016).

CONCLUSIONS

We found no statistically significant difference in freedom from type IA endoleak, retrograde dissection, or disabling stroke observed between the NBS and the BS configuration of the Relay endograft. Proximal landing zone thrombotic apposition was a prominent risk factor for type IA endoleak after TEVAR.

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.

[Update on thoracic endovascular aneurysm repair : New stent graft designs]

BACKGROUND

In the last decade, new stent graft designs have evolved to tackle challenges in thoracic endovascular aortic repair. A specific focus on access vessel issues has led to the introduction of new low-profile endograft designs for most of the major products.

OBJECTIVE

The main objective of this article is to provide an overview of the available publications on new stent graft designs.

MATERIALS AND METHODS

Assessing recent publications on the major reiterations of thoracic endografts, benefits and drawbacks are discussed.

RESULTS

Recent reiterations of major endografts for thoracic aortic endovascular repair have focused mainly on the development of low-profile devices. Through alterations on graft fabric as well as stent material and design, delivery systems were reduced in profile, thus, reducing access vessel complications or enabling an endovascular procedure altogether. Long-term data are already available for one endoprosthesis. Other refinements include in situ adaptation of the stent graft to the aortic arch curvature as well as the option of staged deployment to allow more precision and reduce manipulation close to supra-aortic branches.

CONCLUSIONS

Especially in the case of low-profile endografts, preliminary and long-term results of access vessel complications are promising. In order to draw final conclusions as to how durable the results of aneurysm exclusion are, more long-term studies are warranted.

Unique characteristics of the type B aortic dissection patients with malperfusion in the Vascular Quality Initiative

OBJECTIVE

Type B aortic dissection (TBAD) complicated by malperfusion carries high morbidity and mortality. The present study was undertaken to compare the characteristics of malperfusion and uncomplicated cohorts and to evaluate the long-term differences in survival using a granular, national registry.

METHODS

Patients with TBAD entered into the thoracic endovascular aortic repair/complex endovascular aortic repair module of the Vascular Quality Initiative from 2010 to 2019 were included. The demographic, radiographic, operative, postoperative, in-hospital, and long-term reintervention data were compared between the malperfusion and uncomplicated TBAD groups using t tests and χ² analysis, as appropriate. Overall survival was compared using Cox regression to generate survival curves.

RESULTS

Of the 2820 included patients, 2267 had uncomplicated TBAD and 553 had malperfusion. The patients with malperfusion were younger (age, 55.8 vs 61.2 years; P < .001), were more often male (79.7% vs 68.1%; P < .001), had a higher preoperative creatinine (1.8 vs 1.1 mg/dL; P < .001), had more often presented with an American Society of Anesthesiologists class of 4 or 5 (81.9% vs 58.4%; P < .001), and had more often presented with urgent status (77.4% vs 32.8%; P < .001). In contrast, the uncomplicated TBAD group had had more medical comorbidities, including coronary artery disease and chronic obstructive pulmonary disease, and a larger aortic diameter (4.0 cm vs 4.9 cm; P < .001). The malperfusion group more frequently had proximal zones of disease in zones 0 to 2 (38.6% vs 31.5%; P = .002) and distal zones of disease in zones 9 and above (78.7% vs 46.2%; P < .001), with a greater number of aortic zones traversed (7.7 vs 5.1; P < .001) and a greater frequency of dissection extension into branch vessels (61.8% vs 23.1%; P < .001). Patients with malperfusion also exhibited greater case complexity, with a greater need for branch vessel stenting and longer procedure times. The overall incidence of postoperative complications was greater in the malperfusion group (39.4% vs 17.1%; P < .001) and included a greater rate of spinal cord ischemia (6.3% vs 2.2%; P < .001), acute kidney injury (10.4% vs 0.9%; P < .001), and in-hospital mortality (11.6% vs 5.6%; P < .001). In-hospital reintervention was also greater for the malperfusion patients (14.5% vs 7.4%; P < .001), although the incidence of long-term reinterventions was similar between the two groups (8.7% vs 9.7%; P = .548). A proximal zone of disease in zone 0 to 2 was associated with decreased survival. In contrast, a distal zone of disease in 9 and above, in-hospital reintervention, and long-term follow-up were associated with increased survival. Despite these differences, long-term survival did not differ between the malperfusion and uncomplicated groups (P = .320.) CONCLUSIONS: Patients presenting with TBAD and malperfusion represent a unique cohort. Despite the greater need for branch vessel stenting and in-hospital reintervention, they had similar long-term reintervention rates and survival compared with those with uncomplicated TBAD. These data lend insight with regard to the observed differences between uncomplicated and malperfusion TBAD.

A preliminary analysis of late structural failures of the Navion stent graft in the treatment of descending thoracic aortic aneurysms

OBJECTIVE

Patients in the Valiant Evo U.S. and international clinical trials had positive short-term outcomes; however, late structural failures, including type IIIb endoleaks have been recently discovered. Type IIIb endoleaks are serious adverse events because the repressurization of the aneurysm sac increases the risk of rupture. The purpose of the present study was to detail the imaging patterns associated with the structural failures with the aim of increasing awareness of failing graft presentation, early recognition, and prompt treatment.

METHODS

The Valiant Evo clinical trial was a prospective, single-arm investigation of a thoracic stent graft system. With the recent late structural failures, sites were requested to submit all available imaging studies to date to allow the core laboratory to assess for structural failures such as type IIIb endoleaks, stent ring fractures, and stent ring enlargement. Of the 100 patients originally enrolled in the trial from 2016 to 2018, the core laboratory assessed the imaging studies performed at ≥1 year for 83 patients.

RESULTS

No structural failures of the graft were reported through 1 year of follow-up. At 1 to 4 years, graft structural failures were detected in 11 patients with descending thoracic aortic aneurysms. Of the 11 patients, 5 had a type IIIb endoleak. Four of the five had imaging findings showing stent fractures consistent with the location of the graft seam and one had a type IIIb endoleak attributed to calcium erosion with no stent fracture or ring enlargement. Of the four patients with stent fracture in line with the graft seam, three underwent a relining procedure that successfully excluded the type IIIb endoleak. One of these three patients died 4 days later of suspected thoracic aortic rupture because the distal thoracic endovascular aortic repair extension had been landed in a previously dissected and fragile section of the aorta. The remaining six patients had had stent ring enlargement. One of the six patients had had persistent aneurysm expansion from the time of implantation onward and had died of unknown causes. The remaining five patients have continued to be monitored.

CONCLUSIONS

In the present preliminary analysis, the imaging patterns associated with type IIIb endoleaks, stent fractures, and stent ring enlargement appear to be related to the loss of seam integrity or detachment of the stent rings from the surface of the graft material. The imaging patterns we have detailed should be closely monitored using computed tomography angiography surveillance to allow structural failures to be promptly identified and treated.

Follow-up results of aortic arch cervical debranching performed with the help of a temporary crossover external carotid artery bypass for cerebral protection followed by endovascular thoracic aortic aneurysm repair

OBJECTIVES

Treating aortic arch aneurysms with conventional open surgical and endovascular stent graft procedures is challenging due to the complex anatomy of the arch and the arteries arising from it that nourish the brain. Cerebral protection is of the utmost importance during the treatment of thoracic aneurysms involving the aortic arch.

METHODS

Between May 2014 and November 2018, 7 patients with thoracic aortic aneurysms involving the aortic arch who underwent aortic arch cervical debranching with our technique were reviewed retrospectively. Because all the patients being considered for conventional surgical aortic arch replacement had serious comorbidities, they were selected to receive hybrid therapy. The mean age of the patients was 71.2 ± 9.4 years. One patient was a woman and 6 patients were men. One patient was given general anaesthesia; the remaining 6 patients had a regional block. A crossover temporary bypass was performed between the external carotid arteries with a 6-mm polytetrafluoroethylene graft for cerebral protection in all patients. Thoracic endovascular aortic repair (TEVAR) was successfully performed in all patients except 1 following debranching.

RESULTS

Neurological complications did not occur during the procedures. Patients were followed for a mean of 18.3 ± 4.9 months. One female patient died of exacerbating chronic obstructive pulmonary disease within the first follow-up year. Three other patients died: 1 died of natural causes; 1 died of pneumonia followed by multiorgan failure; and 1 died of myocardial infarction during the mid-term follow-up period. The remaining patients are still being followed and are event free.

CONCLUSIONS

Endovascular treatment of thoracic aortic diseases involving the aortic arch is facilitated when the aortic arch is debranched. Our cerebral protection method with a temporary crossover bypass between the external carotid arteries provides continuous pulsatile blood flow to the brain; hence, neurologically, it is a reliable procedure. The follow-up results of the patients who underwent aortic arch cervical debranching followed by TEVAR depended on their comorbidities.

Early results of a low-profile stent-graft for thoracic endovascular aortic repair

PURPOSE

To assess outcomes of a low-profile thoracic stent-graft in the treatment of thoracic aortic pathologies.

METHODS

A retrospective analysis of all consecutive patients with aortic thoracic pathologies treated with the RelayPro device in two university hospitals between October 2018 and July 2019.

RESULTS

23 patients (65% men; mean age 63.4 ± 15 years) were treated. Pathologies included aortic dissections (n = 10), 5 residual type A (22%) and 5 type B (22%), 6 degenerative aortic aneurysms (26%), 4 penetrating aortic ulcers (17%), and aortic erosion, intramural hematoma and aortic rupture (n = 1 and 4% in each case). Two cases (9%) were emergent and two urgent. Proximal landing was achieved in zones 0 (4%), 1 (4%), 2 (43%), and 3 (26%). Five grafts were frozen elephant trunk extensions. Technical success was 100% with accurate device deployment in the intended landing zone of the aortic arch in all 23 patients and with no Ia/III endoleaks and three (13%) type II endoleaks. Apposition was adequate in 96%. Two patients had post-implantation syndromes (one fever, one leukocytosis). Mean follow-up was 11.6 ± 3.7 months (range, 2-16) with no other complications, secondary interventions or conversions to open surgery. There was no 30-day mortality and no aortic-related mortality; all-cause mortality was 4% during follow-up.

CONCLUSION

A 3-4 French reduced profile in the current generation of stent-grafts facilitates TEVAR particularly in patients with smaller vessels access. Early safety and effectiveness outcomes are favorable, even in endpoints such as deployment accuracy and apposition which may be surrogates for longer-term clinical success and durability.

Long-term Results of Thoracic Endovascular Aortic Repair Using a Low-Profile Stent-Graft

PURPOSE

To evaluate the long-term results associated with the Zenith Alpha thoracic stent-graft, which was designed to address challenging access vessel anatomy.

MATERIALS AND METHODS

A retrospective analysis was conducted of 44 consecutive patients (mean age 72.5±8.3 years; 25 men) treated in a single center between August 2010 and October 2014 with a minimum follow-up of 5 years in survivors. The Zenith Alpha thoracic stent-graft was used to treat thoracic aortic aneurysms (n=37), thoracoabdominal aortic aneurysm (n=5), or penetrating aortic ulcer (n=2). Ten patients (23%) were American Society of Anesthesiologists class IV, and 9 (20%) had nonelective procedures. Access vessel anatomy was demanding (mean minimum diameter 5.4 mm, tortuosity index 1.3). The primary endpoint at 5 years was ongoing clinical success (freedom from aneurysm-/procedure-related death, secondary intervention, type I or III endoleak, infection, thrombosis, aneurysm expansion, rupture, or conversion). Secondary endpoints were freedom from all-cause mortality, device migration, stent fractures, fabric erosions, endoleaks, neurological events, and access vessel complications.

RESULTS

The ongoing clinical success was 84% (37 of 44 patients) owing to 4 aneurysm-related deaths (9%), 3 type I or III endoleaks (1 in a deceased patient), and 1 aneurysm expansion without detectable endoleak. There were 3 access vessel complications (7%), and no postoperative neurological events. Migration was observed in 2 cases (5%). There were no stent fractures or fabric tears.

CONCLUSION

Despite the alterations in stent-graft design and material to reduce profile, the Zenith Alpha thoracic stent-graft showed favorable long-term results even in multimorbid patients with demanding iliac anatomy.

Aneurysms and dissections - What is new in the literature of 2019/2020 - a European Society of Vascular Medicine annual review

More than 6,000 publications were found in PubMed concerning aneurysms and dissections, including those Epub ahead of print in 2019, printed in 2020. Among those publications 327 were selected and considered of particular interest.

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.