Safety and effectiveness of the TREO stent graft for the endovascular treatment of abdominal aortic aneurysms

Anatomical Feasibility of an Off-the-shelf Single-Renal Scalloped Stent-Graft for Hostile Neck Abdominal Aortic Aneurysm: A Preclinical Study

OBJECTIVES

To evaluate the feasibility of a standardized single-renal scallop stent-graft.

DESIGN

Preclinical, single-center, real-world, all-comers, retrospective cohort study.

METHODS

A total of 1347 abdominal aortic aneurysm (AAA) repairs (endovascular and open) performed between 2010 and 2020 were screened for elective treatment and retrievable preoperative high-quality computed tomography angiography (CTA) performed <6 months of the surgical procedure. Six hundred of the included CTAs involved prespecified measurements and a morphological assessment protocol (NCT05150873). The proximal sealing zones suitable for standard stent-graft implantations were further analyzed (N=547). The primary outcome assessed the feasibility of 2 single-renal scallop designs (10×10 mm and 15×10 mm, height × width). The feasibility was the inter-renal length ≥10 mm and ≥15 mm for prototypes #10 and #15, respectively. The secondary outcome quantified hypothetical length and surface improvements comparing those suitable for investigational devices implantation (study group) versus those not (control group).

RESULTS

Of the total, 24.7% (n=135) was feasible with prototype #10. The study versus control group sealing zones were shorter (p=0.008), with a smaller surface (p=0.009) and a higher alpha angle (p=0.039). The length and surface area increased by about 25% and 23%, respectively, (both p<0.001) within the study group and became significantly better versus the control group (standard stent-graft; both p<0.001). Of the total, 7.1% (n=39) was suitable for prototype #15. The study versus control group sealing zones were shorter (p=0.148), with a smaller surface (p=0.077) and a higher alpha angle (p=0.027). The length and surface area increased by about 34% and 31%, respectively, (both p<0.001) within the study group and became significantly higher versus the control group (standard stent-graft; both p<0.001).

CONCLUSIONS

The use of single-renal scalloped stent-graft might be feasible in a considerable number of AAA patients. The breakthrough stands in treating hostile AAAs presenting in mismatched renal arteries, keeping the complexity of the repair as similar as possible to standard endovascular repair with a remarkable improvement in sealing.

CLINICAL IMPACT

The anatomic feasibility of a single renal stent graft for the treatment of "hostile" abdominal aortic aneurysm (AAA) with mismatched renal arteries was evaluated. The experimental device could be feasible in a considerable number of patients with AAA, approaching 25%, and demonstrate significant improvements in sealing. As far as we know, this is the first paper to report the prevalence of mismatched renal arteries in a large cohort of AAA patients in the real world, while proposing a dedicated device. The breakthrough is to keep the complexity of the repair as close as possible to standard endovascular repair.

One-year safety and effectiveness of the Alto abdominal stent graft in the ELEVATE IDE trial

OBJECTIVE

This study reports the results of a prospective, multicenter trial designed to evaluate the safety and effectiveness of the polymer based Endologix Alto Stent Graft System in treating abdominal aortic aneurysms (AAAs), with sealing 7 mm below the top of the fabric in aortic neck diameters from 16 to 30 mm.

METHODS

Seventy-five patients were treated with Alto devices between March 2017 and February 2018 in 16 centers in the United States for infrarenal AAAs (max diameter ≥5.0 cm in diameter or size increase by 0.5 cm in 6 months or diameter ≥1.5 times the adjacent normal aorta). Patients were followed for 30 days, 6 months, and 1 year by clinical evaluation and computed tomography and abdominal x-ray imaging. Treatment success was defined as technical success and freedom from AAA enlargement, migration, type I or III endoleak, AAA rupture or surgical conversion, stent graft stenosis, occlusion, kink, thromboembolic events, and stent fracture attributable to the device requiring secondary intervention through 12 months. Preoperative characteristics, perioperative variables, follow-up clinical evaluations, and radiographic examination results through the first 1 year were analyzed.

RESULTS

The mean patient age was 73 years, with 93% of patients being male. The 30-day major adverse event rate was 5.3%. At 1 year, the primary endpoint was met with a treatment success rate of 96.7%. Through 1-year post-treatment, all-cause mortality was 4.0%. No AAA-related mortality occurred. AAA enlargement was 1.6%, type I endoleak rate was 1.4%, with 100% freedom from type III endoleaks, device migration, device fracture, stent occlusion, or AAA rupture. The device-related secondary intervention rate was 2.7%.

CONCLUSIONS

This prospective study demonstrates the Endologix Alto is safe and effective in treating AAAs with appropriate anatomy at 1 year. The safety endpoint is met by a 5.3% 30-day major adverse event rate, whereas the effectiveness endpoint is met by a treatment success rate of 96%.

Endografts for the treatment of abdominal aortic aneurysms with a hostile neck anatomy: A systematic review

Background

Endovascular aortic repair (EVAR) of abdominal aortic aneurysms (AAAs) has emerged as a better alternative to conventional open surgery for AAAs. The purpose of the review is to define the improvement in the clinical management of the patient with hostile neck AAAs due to the introduction of new endografts while giving a thorough description of their instructions for use (IFUs), main characteristics and part sizing, reporting their outcomes from clinical studies and categorizing their usability.

Methods

A MEDLINE search was conducted using keyword-specific combinations. Clinical studies were searched via the clinicaltrials.gov website. Relevant articles' references were also hand-searched.

Results

We retrieved 640 records describing Alto, Ovation iX, Treovance, Aorfix, Anaconda, Conformable, and Endurant II/IIs endografts. Aortic necks >60° can be managed with Anaconda, Aorfix, and Conformable, which can treat up to 90° necks requiring ≥15 mm (Anaconda ≥20 mm), and Treovance, which is eligible for necks ≤75° with ≥15 mm length. Ovation's innovation of combining polymer-filled O-rings with integral anchors can treat conical necked AAAs giving Ovation iX and Alto an advantage. Short-necked AAAs can be treated with Alto, eligible for necks as short as 7 mm, and Endurant II, which can treat ≥10 mm necks or 4 mm if used in conjunction with the EndoAnchors system, respectively. Alto and Conformable report a 100% technical success rate, absence of AAA-related death, migration, ruptures, and limb occlusion during follow-up. Endurant II and Ovation iX report >99% technical success rate and are almost free from the AAA mortality rate, ruptures, migration, and limb occlusion, while Ovation iX has a high rate of sac dilation (15.5%) in a 5-year follow-up. Anaconda is slightly better than Aorfix and Treovance, which are related to the lowest technical success rates, 98.3%, 96.3%, and 96%, respectively. Aorfix has the highest AAA mortality rate, 4% in a 60 month follow-up.

Conclusion

Most new generation endografts described have comparable results. They broaden the eligibility of patients for EVAR due to their unique technical characteristics described. There is a lack of comparative studies for newer endografts and postmarket clinical studies with long-term results concerning the most recently approved devices described, Alto and Conformable.

Update on the TREO endograft device: overview of its safety and efficacy

INTRODUCTION

The TREO abdominal aortic stent graft system (Terumo Aortic, Sunrise, Fla) is a low-profile, trimodular endovascular endoprosthesis for the endovascular repair of abdominal aortic aneurysm (AAA). The objective of the present study was to collect and discuss all the available modern data of this device highlighting especially its mid-and long-term clinical results.

AREAS COVERED

This updated review article presents the most current results from great-scale clinical studies and the RATIONALE registry involving also angulated neck anatomies and challenging AAA geometries, reflecting the real-world experience.

EXPERT OPINION

The global, multicenter RATIONALE registry prospectively enrolled 202 patients (mean age 73.0 ± 7.8 years) who underwent EVAR. Technical success, primary clinical success and assisted primary patency rate was 96%, 92.2% and 97%, respectively. The clinical success at 1 year was 96%. Another multicenter, non-randomized, clinical trial confirmed also high technical and clinical success. Additionally, a comparative study comparing favorable and hostile necks in AAA, demonstrated a comparable technical success (95.2%), achieving proper sealing and technical success in the hostile neck group. TREO endograft seems to be safe and effective for EVAR, especially in hostile neck anatomies. Long-term outcomes from ongoing registries are awaited to complete these results.

Impact of proximal neck anatomy on short-term and mid-term outcomes after treatment of abdominal aortic aneurysms with new-generation low-profile endografts. Results from the multicentric "ITAlian north-east registry of ENDOvascular aortic repair with the BOltOn Treo endograft (ITA-ENDOBOOT)"

INTRODUCTION

The aim of the study was to evaluate the short-term and mid-term technical and clinical outcomes of the Bolton Treo endograft in subjects with abdominal aortic aneurysm (AAA) requiring endovascular aortic repair (EVAR) and assess if presence of hostile proximal neck would represent a risk factor for increased failure rates.

METHODS

A retrospective review of all consecutive patients who had undergone elective or non-elective EVAR with the Bolton Treo endograft at five institutions located in the North-East of Italy (January 2016-December 2020) was performed. The main exposure variable for this study was presence of hostile (HAN) or friendly (FAN) aortic neck.

RESULTS

A total of 137 consecutive patients were treated with the Bolton Treo endograft at participating institutions; of these 63 (46%) presented HAN while 74 (54%) had FAN. At baseline, no significant differences were observed in the distribution of demographics and comorbidities between study groups. Two type Ia endoleaks (EL) were detected at completion angiography, all in patients with HAN but none in patients with FAN (3% vs 0%, p=.04), but no type III EL were identified in the whole cohort. The median duration of follow-up in the study cohort was 30 months (IQR 22-34 months) and was similar between study groups (p=.87). At three-years, survival estimates were 89% and 91% (p=.82) in patients with HAN and FAN, respectively. At three years, patients with HAN had significantly lower freedom from type IA endoleak as compared with patients with FAN (87% vs 94%, p=.02). No significant differences were found between study groups in the three-year estimates of freedom from reinterventions (80% vs 86%, p=.28). Using cox proportional hazards, presence of type II EL (HR 3.15, 95%CI 1.18-8.5, p=.02) and presence of type IA EL (HR 4.22, 95%CI 1.39-12.85, p=.01) were found as independent predictors for reinterventions in univariate analysis, although they were no longer significant in the multivariate model. Freedom from sac increase >5mm at three years were not significantly different between study groups (92% vs 91%, p=.95).

CONCLUSIONS

Within a contemporary multicentric real-world experience, EVAR with the Bolton Treo endograft shows a satisfactory safety profile in the immediate postoperative phase and acceptable outcomes during mid-term follow-up. Presence of HAN is correlated with development of type Ia EL (either early following stent-graft implantation or late after EVAR) which, in turn, may represent a significant factor leading to reinterventions.

The TREO abdominal aortic stent-graft system

Endovascular aneurysm repair has become a primary treatment modality for patients with abdominal aortic aneurysms due to its less invasive nature and improved peri-operative mortality rates compared with conventional open surgery. Long-term, endovascular aneurysm repair is hindered by the need for reintervention due to a variety of reasons. Device improvements are directed toward improving these long-term outcomes. The current manuscript highlights some of the details of the Terumo Aortic TREO abdominal aortic stent-graft, which was approved in 2020 for clinical use by the US FDA. A brief review of the available clinical outcomes from the US trial, as well as experience in the rest of the world, are provided demonstrating its excellent performance.