Incidence, Long Term Clinical Outcomes, and Risk Factor Analysis of Type III Endoleaks Following Endovascular Repair of Abdominal Aortic Aneurysm

Exploring Type IIIb Endoleaks: A Literature Review to Identify Possible Physical Mechanisms and Implications

Endoleaks are common complications following endovascular aneurysm repair (EVAR). They can be classified into low-pressure and high-pressure endoleaks. High-pressure endoleaks, which include Type I and Type III endoleaks, pose a significant risk of rupture and require urgent treatment. The aim of our study is to review published case reports and case series to assess the impact of Type IIIb endoleaks in EVAR and to identify possible mechanisms contributing to these endoleaks. This review targeted case reports and case series published between January 1998 and December 2022. A total of 62 case reports and case series were identified, encompassing 156 patients with Type IIIb endoleaks. Data collection was performed by three consultants who thoroughly discussed each report before registering it into an analyzable data set. Our analysis revealed that, beyond material imperfections, certain endograft configurations or conformations, endograft redundancy, and the physical forces acting on the grafts may lead to increased stress on specific parts of the endografts, potentially exceeding their design limits. Factors contributing to redundancy and unfavorable conformation of the endograft include secondary interventions for any cause (such as other types of endoleaks), EVAR performed outside the instructions for use (IFUs), endograft migrations, or larger initial aneurysm diameter.

Early experience with patient-specific unibody bifurcated fenestrated-branched devices for complex endovascular aortic aneurysm repair

OBJECTIVE

Short distances between the lowest visceral/renal artery and the aortic bifurcation are technically challenging during complex endovascular aortic aneurysm repair (EVAR), particularly after previous infrarenal repair. Traditionally, inverted limb bifurcated devices have been used in addition to fenestrated-branched (FB) endografts, but short overlap, difficult cannulation, and potential crushing of bridging stents are limitations for their use. This study reviews the early experience of patient-specific company manufactured devices (PS-CMDs) with a unibody bifurcated FB design for complex EVAR.

METHODS

Consecutive complex EVAR procedures over a 34-month period with unibody bifurcated FB-devices as part of physician-sponsored investigational device exemption studies at two institutions were reviewed. Unibody bifurcated FB designs included FB bifurcated or fenestrated inverted limb devices. End points included technical success, survival, frequency of type I or III endoleaks, limb occlusion, and secondary interventions.

RESULTS

Among 168 patients undergoing complex EVAR, 33 patients (19.6%; 78.7% male; mean age, 77 years) received unibody bifurcated FB PS-CMDs. FB bifurcated and fenestrated inverted limb devices were used in 31 (93.9%) and 2 (6.06%) patients, respectively. The median maximum aneurysm diameter was 61 mm (interquartile range [IQR], 55-69 mm). Prior EVAR was reported by 29 patients (87.9%), of whom 2 (6.06%) had suprarenal stents. A short distance between the lowest renal artery and aortic bifurcation was demonstrated in 30 patients (90.9%), with median distance of 47 mm (IQR, 38-54 mm). Preloaded devices were used in 23 patients (69.7%). A total of 128 fenestrations were planned; 22 (17.2%) were preloaded with guidewires and 5 (3.9%) with catheters. The median operative time was 238 minutes (226-300 minutes), with a median fluoroscopy time of 65.5 minutes (IQR, 56.0-77.7 minutes) and a median dose area product of 147 mGy∗cm2 (IQR, 105-194 mGy∗cm2). Exclusive femoral access was used in 14 procedures (42.4%). Technical success was 100%. Target vessel primary patency was 100% at a median follow-up time of 11.7 months (IQR, 3.5-18.6 months). Two patients (6.06%) required reintervention for iliac occlusion; one patient required stenting and the other a femoral-femoral bypass. No aortic-related deaths occurred after the procedure. During follow-up, 11 type II endoleaks (33.3%) and 1 type Ib endoleak (3.03%) were detected; the latter was treated with leg extension. No type Ia or III endoleaks occurred.

CONCLUSIONS

Complex EVAR using unibody bifurcated FB-PS-CMDs is a simple, safe, and cost-effective alternative for the treatment of patients with short distances between the renal arteries and the aortic bifurcation. Further studies are required to assess benefits and durability of unibody bifurcated FB devices.

Type III Endoleak Incidence and Outcomes in Endovascular Aortic Repair: Comparison of Anatomical and Proximal Fixation Devices

PURPOSE

To evaluate the influence of endograft fixation type on the incidence, treatment, and outcomes of type III endoleaks (TIIIELs).

MATERIALS AND METHODS

Abdominal aortic aneurysms (AAAs) treated with bifurcated endografts between 1994 and 2020 were prospectively collected and reviewed. The endograft included were classified as "Anatomical Fixation" (AF) (Powerlink [Endologix] and AFX [Endologix]) or "Proximal Fixation" (PF). The primary outcome was the incidence of TIIIEL over time, stratified by fixation type. Secondary outcomes included between-group comparisons of baseline characteristics, intraoperative details during TIIIEL correction, and survival analysis after TIIIEL diagnosis.

RESULTS

A total of 2065 endovascular aneurysm repairs were performed: 872 (42.2%) with AF and 1193 (57.8%) with PF devices. The estimated incidence of TIIIEL at 1, 5, and 10 years was 0.4%, 4.2%, and 7.3%, and 0.5%, 3.2%, and 4.6% for AF and PF, respectively (p=0.157), and fixation type was not associated with TIIIEL development in the competing risk regression model (p=0.101). The cumulative overall survival rate in patients diagnosed with TIIIEL did not differ significantly between the groups (p=0.077). The rate of recurrent TIIIELs was significantly lower in the AF group (7.1% vs 22.7%; p=0.044); however, no significant difference was found in secondary reintervention between the two groups (11.9% vs 27.3%, p=0.074). Patients with angulated and calcified aortic neck (SHR 3.4, 95% CI 1.2-9.6, p=0.022) and larger aneurysms (SHR 1.2; 95% CI 1.1-1.3; p<0.001) had a higher risk of TIIIEL. Likewise, the use of three or more endograft components increased the risk of TIIIEL by 3.1 times (SHR 3.1; 95% CI 1.7-5.4; p<0.001).

CONCLUSIONS

The occurrence of TIIIELs was not affected by the type of endograft fixation. For larger abdominal aortic aneurysms (AAAs) and aneurysms with angulated and calcified aortic necks, there is a higher likelihood of developing TIIIELs during follow-up, regardless of the endograft type used.

CLINICAL IMPACT

The type of fixation does not influence the incidence of TIII ELs. EVAR in larger AAAs and aneurysms with angulated and calcified aortic necks have a higher risk of developing TIII EL. Moreover, the risk of TIII EL is considerably increased by the use of three or more modular components.

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.

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.