Initial Experience and Potential Advantages of AFX2 Bifurcated Endograft System: Comparative Case Series

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.

Combined AFX2 with thoracic stent graft: A different endovascular approach of an abdominal aorta aneurysm

The AFX2 endovascular repair system is a unibody, bifurcated stent graft that can be used in an abdominal aortic aneurysm associated with anatomical challenges, especially if it is combined with different aortic cuffs. The use of an AFX2 main body combined with a thoracic stent graft as a proximal aortic cuff was selected to treat a 77-year-old male patient with abdominal aortic aneurysm. The AFX2 endograft combined with a proximal thoracic aortic cuff plays a safe and effective role in treating complex infrarenal abdominal aortic aneurysm that may otherwise be technically more challenging with the open technique and inaccessible with the traditional endovascular technique.

Late Type III Endoleak after Loss of Component Overlap after EVAR with AFX2 Device: A Case Report

Addressing the high incidence of late type III endoleaks in previous AFX models, Endologix upgraded the device material and updated its recommendation regarding component overlap. However, whether upgraded AFX2 models are safe for endoleaks remains controversial. Here we report a case of a 67-year-old male with an AFX2-implanted abdominal aortic aneurysm experiencing a delayed type IIIa endoleak. Aneurysmal sac enlargement occurred 36 months post-endovascular aneurysm repair (EVAR), with a computed tomography scan at 52 months revealing component overlap loss and a significant type IIIa endoleak. We performed endograft explantation and endoaneurysmal aorto-bi-iliac interposition grafting. Our findings suggest that sufficient component overlap is necessary when using an AFX2 endograft outside the manufacturer's instructions for use to prevent late type IIIa endoleaks. Moreover, patients who undergo EVAR with AFX2 for tortuous large aortic aneurysms should be carefully monitored for conformational changes.

Early Clinical Outcomes of the Active Seal Technology of the AFX Endovascular Aortic Aneurysm System With the VELA Cuff for Patients With a Conical Proximal Neck

PURPOSE

To evaluate the efficacy of the Active Seal technology employed in the AFX endovascular aortic aneurysm system (AFX), during endovascular aneurysm repair (EVAR) in patients with abdominal aortic aneurysms (AAAs) having a conical proximal neck.

MATERIALS AND METHODS

A retrospective analysis of the EVAR for AAA with a conical proximal neck using the AFX was performed at 17 Japanese hospitals between January 2016 and August 2020. The conical proximal neck was defined as a cone-shaped proximal neck, with more than 10% diameter increase within a 15 mm length at the proximal landing zone. All anatomical analyses were performed in the core laboratory, and cases with parallel walls within the proximal neck adequate for the landing zone were excluded from the study.

RESULTS

This study included 53 patients, but only 39 patients (mean age, 76.6 ± 6.7 years; 87.0% males; mean aneurysm diameter, 52.0 ± 8.0 mm) were analyzed after being characterized as having a pure conical neck by the core laboratory. The mean proximal neck diameters at the lower renal artery and proximal edge of the aneurysm were 20.0 ± 2.9 mm and 27.5 ± 4.9 mm, respectively. The mean proximal neck length was 21.5 ± 6.0 mm. Instructions for use violations other than the conical neck were observed in 15 patients (38.5%). The VELA cuff was used in all cases; however, additional proximal cuff was required in 9 more cases (23.1%). The Active Seal technology was able to significantly extend the proximal sealing zone from 21.5 ± 6.0 to 26.0 ± 12.2 mm (p = .047). Thirty-six patients completed the 12-month follow-up (one patient was lost to follow-up, and 2 patients died from causes unrelated to the aneurysm), and there were no type-1a and 3 endoleaks with only one reintervention (2.6%) related to type 1b endoleak in the 12-month period. Furthermore, there was no significant enlargement of the proximal neck diameter at 12 months (at 1 month: 20.6 ± 3.4 mm and at 12 months: 21.3 ± 3.8 mm; p = .420).

CONCLUSION

The Active Seal technology of the AFX significantly extended the proximal seal zone and no type-1a endoleak and proximal neck dilation was observed in patients with conical proximal neck at 12 months.

Successful endovascular repair of iliac artery aneurysms with unsuitable anatomy by combining unibody bifurcated endograft and iliac branch systems to preserve hypogastric artery blood flow: a report of two cases

Background

To overcome the anatomical limitation of a narrow aorta and short length from the renal artery to the terminal aorta, unibody endograft AFX2 and iliac branch endoprosthesis (IBE) can be combined.

Case presentation

Case 1: The first patient was an 89-year-old woman who had a right saccular common iliac artery (CIA) aneurysm (38 mm); the abdominal aorta was not aneurysmal (diameter, 19 mm). The right CIA’s origin was 10 mm in diameter. A bifurcated AFX2 was placed in an ordinary manner. Then, IBE was inserted in the right leg of the AFX2. Case 2: The second patient was an 87-year-old man diagnosed with an abdominal aortic aneurysm (55 mm), right dissecting CIA aneurysm (20 mm), and right hypogastric artery aneurysm (22 mm) extending to the bifurcation of the superior and inferior gluteal arteries. The length between the renal artery and terminal aorta was 107 mm. The beginning of the right CIA was segmentally stenotic (13 mm). A bifurcated AFX2 was placed in the infrarenal aorta; IBE was advanced to the origin of the right limb of the AFX2. To control the type 1b endoleak, the right superior gluteal artery was embolized with coils and internal iliac components were deployed toward the inferior gluteal artery. Satisfactory results were obtained in both cases.

Conclusion

The AFX2 main body and IBE could be combined to preserve hypogastric blood flow and overcome anatomical limitations.

Midterm outcomes of 455 patients receiving the AFX2 endovascular graft for the treatment of abdominal aortic aneurysm: A retrospective multi-center analysis

Since being introduced into clinical practice the AFX family of endografts has undergone labelling updates, design and manufacturing changes to address a Type III failure mode. The published literature on the performance of the current endograft-AFX2 -is limited to small series with limited follow up. The present study reports the largest series of patients implanted with AFX2 for the treatment of abdominal aortic aneurysms. The study was a retrospective, 5 center study of patients receiving an AFX2 endograft from January 2016 until Dec 2020. Electronic case report forms were provided to four of the centers, with one additional site providing relevant outcomes in an independent dataset. Relevant outcomes were reported via Kaplan-Meier analysis and included all-cause mortality, aneurysm-related mortality, post EVAR aortic rupture, open conversion, device related reinterventions and endoleaks. Among a cohort of 460 patients, 405 underwent elective repair of an AAA, 50 were treated for a ruptured AAA, and 5 were aorto-iliac occlusive disease cases. For the elective cohort (mean age 73.7y, 77% male, mean AAA diameter 5.4cm), the peri-operative mortality was 1.7%. Freedom from aneurysm-related mortality was 98.2% at 1,2,3 and 4 years post-operatively, there were no post-operative aortic ruptures, and 2 patients required open conversion. Freedom from Type Ia endoleaks was 99.4% at 1, 2, 3 and 4 years. Freedom from Type IIIa and Type IIIb endoleaks were 100% and 100% (year 1), 100% and 99.6% (year 2), 99.4% and 99.6% (year 3), 99.4% and 99.6% (year 4) respectively. Freedom from all device-related reintervention (including Type II endoleaks) at 4 y was 86.8%. The AFX2 endograft appears to perform to a satisfactory standard in terms of patient centric outcomes in mid-term follow up. The Type Ia and Type III endoleaks rates at 4y appear to be within acceptable limits. Further follow up studies are warranted.

Unibody bifurcated aortic endograft: device description, review of the literature and future perspectives

The unibody (Powerlink/AFX/AFX2) Endovascular AAA device (Endologix Inc., CA, USA) presents a unique design with its long main body and two innate limbs. The device is designed to be deployed and sits on the native aortoiliac bifurcation and represents the only one-piece bifurcated endograft designed to use anatomical fixation for endograft stabilization. According to published literature, the unibody device seems to represent a valid choice in the treatment of abdominal aortic aneurysms. This particular device would seem to satisfactorily perform even in the treatment of more compressed aneurysms (also in off-label association with parallel grafts) and in occlusive pathologies. Ongoing studies will provide new real-life data in a large and unselected patient population to better understand the device’s advantages and limitations.

The Potential of AFX Iliac Extension in Abdominal Aortic Aneurysms with High Iliac Tortuosity

Recently, endovascular aortic aneurysm repair (EVAR) is the most common surgery for abdominal aortic aneurysm (AAA). However, iliac limb complications of EVAR often cause problems in patients with high iliac tortuosity. There is no difference of rate of iliac limb complication among EVAR devices, such as Excluder, Endurant, and Zenith in high iliac tortuosity. But there has been not reported about AFX. We studied AFX iliac extension as it is the only stent graft with an endoskeletal framework. This study aimed to evaluate the AFX iliac extension patency in a case in vitro and to use it in seven cases of AAA with high iliac tortuosity. The silicon tube inserted in the AFX iliac extension was flexed at 30, 60, 90, and 120 degrees, and the lumen of the iliac extension was monitored using an underwater camera in the circulatory system. During the experiment, the Iwaki Bellows Pump (IWAKI CO., LTD., Tokyo, Japan) produced a pulsating flow. We used this in seven patients with AAA high iliac tortuosity cases between November 2018 and May 2019. If the silicon tube inserted in the AFX iliac extension was flexed at 60 and 120 degrees, the stent protruded into the lumen. However, the graft was dilated at all degrees. All seven patients with AFX iliac extension had no complications and a patent iliac artery. The AFX iliac extension can reduce iliac limb complications in cases of high iliac tortuosity.

Adjunctive Procedures for Challenging Endovascular Abdominal Aortic Repair: When Needed and How Effective?

Endovascular aneurysm repair (EVAR) is now considered the first choice treatment modality for abdominal aortic aneurysm (AAA) treatment. Advocates for endovascular strategies will try to treat all AAA by EVAR, regardless if the anatomy is conducive for treatment or not. However, the long-term outcomes of EVAR outside the instructions for use (IFU) due to a hostile aneurysmal neck or iliac artery anatomy are known to be poor. The EVAR procedures can be classified according to the technical difficulty, IFU, and need for visceral revascularization: standard, adjunctive, and complex EVAR. The situation required for adjunctive procedures can be classified as the following four steps: a hostile neck (i.e., short or severely angled); large inferior mesenteric or lumbar artery; tough iliac artery anatomy, such as a short common iliac artery and stenotic external iliac artery; and limitations in vascular access. This article will discuss the adjunctive procedures to overcome hostile aneurysm neck and unsuitable iliac artery anatomy.