A Retrospective Evaluation of Intra-Prosthetic Thrombus Formation After Endovascular Aortic Repair in Cook Zenith Alpha and Medtronic Endurant II Patients

The Enzen Trial: Analysis of EVAR Endoprosthesis Zenith and Endurant for Infrarenal Aortoiliac Aneurysms Regarding Outcomes, Endoleaks, and Reinterventions

OBJECTIVE

The main objective of this paper is to analyze the outcomes regarding endoleaks, reinterventions, and death related to aneurysm complications in patients submitted to endovascular repair (EVAR) for abdominal aortoiliac aneurysm (AAA) using Endurant II (Medtronic) and Zenith Flex (Cook) endografts.

METHODS

This was a prospective, consecutive cohort study of patients with AAA who underwent EVAR between January 2019 and December 2022. Two groups of patients were evaluated: Group Endurant (patients submitted to EVAR with the use of Endurant II) and Group Zenith (patients submitted to EVAR with the use of Zenith Flex).

RESULTS

A total of 156 patients were evaluated. Group Zenith (67 patients, 42.9%) and Group Endurant (89 patients, 57.1%). The perioperative mortality was 5.1%, eight patients (six patients Group Zenith, and two patients Group Endurant, p=0.054). There were 28 patients (17.9%) submitted to urgent repair of the aneurysm (expansion or rupture), with no differences among the groups. There were 36 cases (23.1%) of later endoleak, with a higher incidence in Zenith group (23 patients, 34.3%) than Endurant group (13 patients, 14.6%, p=0.002), most of them Type II endoleak (21 patients, 13.4%). There were 12 cases of Type I endoleak, also with a higher prevalence in Zenith group (13.4%) than Endurant group (3.4%, p=0.002). Moreover, regarding limb graft occlusion (LGO), there were nine patients (5.8%), with a higher prevalence in Zenith group (9%) than Endurant group (3.4%, p=0.045). The overall survival in a Kaplan-Meier at 720 days was 82.3% in the Zenith group and 89.1% in the Endurant group, with no statistical significance among the groups (p=0.09). The freedom from reintervention rates in a Kaplan-Meier at 720 days was 82.8% in the Zenith group and 93.2% in the Endurant group (p=0.001).

CONCLUSION

In this present study, Zenith endograft had higher rates of endoleaks, aneurysms related mortality, LGO and reinterventions than patients submitted to Endurant II endografts. The linear regression analysis showed that the presence of endoleaks, type of endograft device (Zenith graft) and limb graft occlusion were related to higher reintervention rates.

CLINICAL IMPACT

In this present study, Zenith endograft had higher rates of endoleaks, aneurysms related mortality, limb graft occlusions and reinterventions than patients submitted to Endurant II endografts. The main impact and the innovation that this article provides is an opportunity to evaluate and choose the best endograft suitable for the patient with AAA during EVAR.

Endovascular repair for infra-renal aortic aneurysms with supra-renal fixation endoprosthesis: Results and outcomes

OBJECTIVE

The main objective of this paper is to evaluate the outcomes regarding endoleaks, reinterventions, and death related to aneurysm complications in patients submitted to endovascular repair (EVAR) for abdominal aortoiliac aneurysm (AAA) using Endurant II (Medtronic) and Zenith Flex (Cook) endografts.

METHODS

This was a prospective, consecutive cohort study of patients with AAA who underwent EVAR with the use of Endurant II stent graft and Zenith Flex endograft.

RESULTS

A total of 156 patients submitted to EVAR were evaluated. The perioperative mortality was 5.1%, 8 patients. The median clinical follow-up period was 760 ± 80 days. There were 28 patients (17.9%) submitted to urgent repair of the aneurysm (symptomatic expansion or rupture) and 128 patients (82.1%) submitted to elective repair. There were 36 cases (23.1%) of later endoleak and most of them are Type II endoleaks (21 patients, 13.4%). There were 12 cases of Type I endoleak. Moreover, regarding limb graft occlusion (LGO), there were 9 patients (5.8%). The overall survival rate in Kaplan-Meier analysis at 720 days was 84.8% in the total cohort. The freedom from reintervention rate in Kaplan-Meier analysis at 720 days was 92.7% in the total cohort. The linear regression analysis for survival rates showed that chronic kidney disease (p = .03; hazard ratio (HR) = 2.82, CI = 1.07-4.44) was the only factor related to poorer survival rates in both univariate and multivariate analyses. The linear regression analysis showed that the presence of endoleaks (p < .001, HR = 6.69, CI = 2.26-8.48) and limb graft occlusion (p < .001, HR = 8.02, CI = 1.60-9.99) were related to reintervention in both univariate and multivariate analyses.

CONCLUSION

In this present study, supra-renal fixation endograft devices were safe and efficient in treating AAA, with satisfactory results and no renal compromise. The linear regression analysis showed that the presence of endoleaks and limb graft occlusion were related to higher reintervention rates in both univariate and multivariate analyses.

Reintervention Rate after Treatment with the INCRAFT AAA Ultra-Low-Profile Stent Graft System

BACKGROUND

The INCRAFT stent graft system is an ultra-low-profile endograft for the exclusion of infrarenal aortic aneurysms. In the market approval studies, an increased rate of device-related complications was observed and the endograft was approved with mandated postmarketing investigations. Our aim was to analyze mid-term outcomes of a real-world patient cohort treated with the INCRAFT endograft.

METHODS

Consecutive patients treated with the INCRAFT endograft between February 2015 and December 2022 at a single institution were included. In accordance with the Society for Vascular Surgery reporting standards, safety endpoints were reported and outcome endpoints included reinterventions, technical success, aortic-related and overall-mortality, endoleak, stent fracture, and endograft migration >5 mm.

RESULTS

Eighty patients (85% male) with a mean age of 76 ± 7 years were included. Fifty-two patients (65%) were treated within the endograft's instruction for use. Mean aortic diameter was 59 ± 10 mm and 91% of the procedures were performed percutaneously. Mean follow-up (FU) was 37 ± 25 months and there was no aortic- or procedure-related mortality. Reinterventions occurred in 25 patients (31%) with a freedom from reintervention at 1, 3, and 5 years of 84%, 66%, and 55%. The most frequent reinterventions were limb graft stenting (23%) and type II endoleak embolization (14%). Limb occlusion rate was 9% and in 3 patients (4%) distal endograft migrations >5 mm occurred. Persisting type II endoleaks were observed in 29% and aneurysm diameter was stable in 41% and had shrunk in 38%. Three type III endoleaks (4%) developed during FU and 4 open conversions (5%) were necessary. No known risk factors, including treatment outside instruction for use, were predictive for reinterventions.

CONCLUSIONS

Treatment of infrarenal aortic aneurysms with the INCRAFT stent graft system was safe and successful. Nevertheless, a substantial rate of reinterventions was necessary during FU to maintain endograft patency and prevent aneurysm growth.

Clinical Performance of the Low Profile Zenith Alpha Abdominal Endovascular Graft: 2 Year Results from the ZEPHYR Registry

OBJECTIVE

The midterm outcomes of the low profile Zenith Alpha Abdominal Endovascular Graft from the ZEnith alPHa for aneurYsm Repair (ZEPHYR) registry are reported.

METHODS

The ZEPHYR registry is a physician initiated, multicentre, non-randomised, core laboratory controlled, prospective registry. Inclusion criteria were patients with a non-ruptured abdominal aortic aneurysm with a maximum diameter ≥ 50 mm or enlargement > 5 mm within 6 months, with a site reported infrarenal neck length of ≥ 10 mm and with the intention to electively implant the Zenith Alpha abdominal endograft. Patients from 14 sites across Germany, Belgium, and the Netherlands were included. The primary endpoint was treatment success, defined as technical success and clinical success. Technical success was defined as successful delivery and deployment of the endograft in the planned position without unintentional coverage of internal iliac or renal arteries, with successful removal of the delivery system. Clinical success was defined as freedom from aneurysm sac expansion > 5 mm, type I or type III endoleaks, aneurysm rupture, stent graft migration > 10 mm, open conversion, and stent graft occlusion.

RESULTS

Three hundred and forty-seven patients were included in the ZEPHYR registry. The median clinical follow up was 743 days (interquartile range [IQR] 657, 806) with a median imaging follow up of 725 days (IQR 408, 788). Treatment success at 6 months, 1, and 2 years was 92.5%, 90.4%, and 85.3%, respectively. Freedom from secondary intervention was 94.3%, 93.4%, and 86.9%, respectively. The predominant reason for secondary intervention was limb complications. Freedom from limb occlusion (per patient) at 6 months, 1, and 2 years was 97.2%, 95.8%, and 92.5%, respectively. Univariable and multivariable Cox regression analyses could not identify any independent predictor for limb complications.

CONCLUSION

While treatment success is comparable with other commercially available grafts, the rate of limb complications at 2 years is of concern. The manufacturer's instructions for use should be followed closely. Further studies are necessary to investigate the root cause of the increased rate of limb complications with the Zenith Alpha Abdominal Endovascular Graft.

Safety Evaluation of Unibody Endografts for Abdominal Aortic Aneurysm Repair: A Systematic Review and Meta-Analysis

BACKGROUND

The unibody bifurcated aortic endograft (AFX/AFX2) has emerged as a treatment option for abdominal aortic aneurysms (AAAs). This systematic review and meta-analysis aimed to evaluate the safety of the unibody endograft.

METHODS

A literature search was conducted in Cochrane Library, Scopus, Web of Science, and PubMed. Studies assessing the unibody endograft for AAA repair between 2014 and 2023 were included. The defined primary outcomes were the incidences of type I, II, and III endoleaks. The secondary outcomes were access site problems, aneurysm-related mortality, aneurysm rupture, all-cause mortality, aneurysm sac growth, limb occlusion, stent graft migration, and technical success rate.

RESULTS

Fourteen studies including 12 observational studies and 2 randomized controlled trials were included in the systematic review. The meta-analysis included 10 studies with 12,690 patients that reported the measured outcomes, and excluded 4 studies that did not. Type II endoleaks had the highest incidence of 12% (95% confidence interval [CI]: 4-20%), followed by type III endoleaks with an incidence of 3% (95% CI: 1-5%). The incidence of type I endoleaks was 1% (95% CI: 0-2%). A subgroup analysis by follow-up duration showed that type II endoleak incidence was higher after 1 to 2 years of follow-up than 3 to 4 years of follow-up. The incidence of aneurysmal mortality was 2% (95% CI: 0-7%), limb occlusion was 1% (95% CI: 0-1%), stent graft migration was 1% (95% CI: 0-2%), aneurysmal rupture was 6% (95% CI: 2-11%), access site problems were 7% (95% CI: 2-13%), aneurysm sac growth was 2% (95% CI: 0-4%), all-cause mortality was 21% (95% CI: 4-38%), and technical success rate was 100% (95% CI: 98-100%).

CONCLUSIONS

The unibody endograft is a safe and minimally invasive approach for AAA repair. However, potential complications necessitate close patient follow-up after the intervention.

Cook Zenith Alpha Endograft: A Protocol to Minimise Limb Graft Occlusion

OBJECTIVE

Numerous articles have reported an increased incidence of limb graft occlusion (LGO) with the Cook Zenith Alpha endograft compared with other endografts in endovascular aortic aneurysm repair (EVAR). The present study aimed to assess the rate of LGO after EVAR in particular with the Cook Zenith Alpha device when adhering to a standardised protocol designed to prevent limb related complications.

METHODS

This was a non-sponsored retrospective study performed in two university vascular surgery centres employing the same protocol for limb complication prevention during EVAR from 2016 to 2019. The protocol encompassed: (1) angioplasty of any common or external iliac artery with > 50% stenosis before endograft navigation; (2) proximal sealing zone of limbs at the same level of the flow divider with minimum overlap, which is more restrictive than the Cook Zenith Alpha instructions for use; (3) semi-compliant kissing ballooning of limbs; (4) limb stenting for any residual tortuosity, kinking, or stenosis; and (5) adjunctive common and external iliac stenting for residual stenosis or dissection after EVAR. Patients enrolled in this study were treated with standard aortobi-iliac EVAR. Follow up was performed by clinical visit and duplex ultrasonography at discharge, six months, and yearly thereafter. The primary endpoint was to evaluate the LGO rate with different EVAR devices (Cook Zenith Alpha, Gore C3, and Medtronic Endurant) and to determine potential risk factors for LGO associated with the Zenith Alpha.

RESULTS

In the study period, 547 EVARs were considered: 233 (42.6%) Cook Zenith Alpha, 196 (35.8%) Gore Excluder, and 118 (21.6%) Medtronic Endurant. The mean follow up was 44 ± 23 months, and the five year freedom from LGO was 97 ± 3%, without differences between groups (97 ± 2%, 95 ± 3%, and 100% with Cook Zenith Alpha, Medtronic Endurant, and Gore Excluder, respectively; p = .080). In the Zenith Alpha group, intra-operative adjunctive iliac artery angioplasty, iliac artery stenting, or iliac limb stenting was performed in 8%, 3.4%, and 9.7% of cases, respectively. Analysis of potential risk factors for LGO identified external iliac artery distal landing and large main bodies (ZIMB 32 - 36) to be independently associated with LGO during follow up (hazard ratio [HR] 18, 95% confidence interval [CI] 3 - 130, p = .004; and HR 12, 95% CI 1.2 - 130, p = .030, respectively).

CONCLUSION

The present experience with a protocol for limb complication prevention allows achievement of a low rate of LGO at five years with Zenith Alpha endografts similar to other endografts. Specific risk factors for the Cook Zenith Alpha endograft are external iliac artery distal landing and the use of a large main body (ZIMB 32 - 36).

Early Clinical Results From the Japanese Prospective Multicenter Study to Evaluate Zenith Alpha Abdominal Stent Graft for Abdominal Aortic Aneurysm (JUSTICE) Registry Demonstrate Acceptable Limb Patency at 12 Months

PURPOSE

Recent reports of the Zenith Alpha abdominal endovascular graft (Zenith Alpha AAA, Cook, Inc., Bloomington, Indiana) have demonstrated an unexpectedly high incidence of limb graft occlusion (LGO). The purpose of this study was to prospectively evaluate the performance of the Zenith AAA in Japan, with a specific focus on LGO.

MATERIALS AND METHODS

All endovascular aneurysm repairs (EVARs) for abdominal aortic aneurysms performed using the Zenith Alpha AAA from July 2020 to October 2021 in 23 Japanese hospitals were prospectively evaluated. All computed tomographic images were analyzed in the core laboratory. Late complications were defined as any aneurysm-related events occurring >30 days after EVAR, including aneurysm sac enlargement of >5 mm and any reinterventions performed. Endoleaks without sac enlargement or reintervention were excluded as late complications.

RESULTS

During the study period, 147 EVARs were performed using the Zenith Alpha AAA. The mean patient age was 76.5±7.7 years, 84.4% of patients were male, and the mean aneurysm diameter was 52.4±9.2 mm. Instruction-for-use violations were observed in 76 patients (51.7%), primarily associated with a severely angulated proximal neck (>60°). There were six intraoperative complications and 62 additional intraoperative treatments reported, most of which involved preemptive coil embolization of the inferior mesenteric artery (37 cases). Technical success, defined as the absence of type 1 or 3 endoleaks on final angiography, was achieved in 99.3% of patients. At 12 months, there was only one case of type 1/3 endoleak (0.8%) and one aneurysm sac enlargement exceeding 5 mm (0.8%); however, a high incidence of type 2 endoleaks was observed in 35.2% of patients, and aneurysm sac regression exceeding 5 mm was achieved in 30.1% of patients. Nine late complications were observed, and the rate of freedom from late complications at 12 months was 93.5%, encompassing four LGOs and one limb graft stenosis (3.4%).

CONCLUSIONS

In contrast to recent reports, our Japanese multicenter prospective study demonstrated satisfactory early clinical results, including an acceptable LGO rate, for the low-profile Zenith Alpha AAA. Long-term follow-ups will be performed to confirm the persistence of these outcomes.

CLINICAL IMPACT

This study prospectively evaluated the performance of 147 Zenith Alpha AAAs used for endovascular aneurysm repair with core-lab adjudication focusing especially on limb graft occlusion (LGO). At 12 months, aneurysm sac regression exceeding 5 mm was achieved in 30.1% of patients, and there was only one type 1/3 endoleak, one aneurysm sac enlargement (>5 mm), and nine late complications including five LGOs (3.4%), resulting in rate of freedom from late complications at 93.5%. Satisfactory early clinical results, including an acceptable rate of LGO can be achieved, particularly with cautious usage of the Zenith Alpha Spiral-Z Endovascular Leg." 5mm), and nine late complications including five LGOs (3.4%), resulting in rate of freedom from late complications at 93.5%. Satisfactory early clinical results, including an acceptable rate of LGO can be achieved, particularly with cautious usage of the Zenith Alpha Spiral-Z Endovascular Leg.

Editor's Choice -- European Society for Vascular Surgery (ESVS) 2024 Clinical Practice Guidelines on the Management of Abdominal Aorto-Iliac Artery Aneurysms

OBJECTIVE

The European Society for Vascular Surgery (ESVS) has developed clinical practice guidelines for the care of patients with aneurysms of the abdominal aorta and iliac arteries in succession to the 2011 and 2019 versions, with the aim of assisting physicians and patients in selecting the best management strategy.

METHODS

The guideline is based on scientific evidence completed with expert opinion on the matter. By summarising and evaluating the best available evidence, recommendations for the evaluation and treatment of patients have been formulated. The recommendations are graded according to a modified European Society of Cardiology grading system, where the strength (class) of each recommendation is graded from I to III and the letters A to C mark the level of evidence.

RESULTS

A total of 160 recommendations have been issued on the following topics: Service standards, including surgical volume and training; Epidemiology, diagnosis, and screening; Management of patients with small abdominal aortic aneurysm (AAA), including surveillance, cardiovascular risk reduction, and indication for repair; Elective AAA repair, including operative risk assessment, open and endovascular repair, and early complications; Ruptured and symptomatic AAA, including peri-operative management, such as permissive hypotension and use of aortic occlusion balloon, open and endovascular repair, and early complications, such as abdominal compartment syndrome and colonic ischaemia; Long term outcome and follow up after AAA repair, including graft infection, endoleaks and follow up routines; Management of complex AAA, including open and endovascular repair; Management of iliac artery aneurysm, including indication for repair and open and endovascular repair; and Miscellaneous aortic problems, including mycotic, inflammatory, and saccular aortic aneurysm. In addition, Shared decision making is being addressed, with supporting information for patients, and Unresolved issues are discussed.

CONCLUSION

The ESVS Clinical Practice Guidelines provide the most comprehensive, up to date, and unbiased advice to clinicians and patients on the management of abdominal aorto-iliac artery aneurysms.