Transcaval embolization for type II endoleak after endovascular aortic repair of infrarenal, juxtarenal, and type IV thoracoabdominal aortic aneurysm

Transcaval embolisation of type-II endoleaks - The Australian experience

OBJECTIVES

Embolizing an abdominal aortic aneurysm sac through a transcaval approach is a novel approach to treat type-II endoleaks that occur following aortic endografting. This study reviews the outcomes of this treatment in one of the few centres in Australia that offers this procedure.

METHODS

A retrospective cohort study was conducted, including patients who had received transcaval embolisation of type-II endoleak over a 9-year period. The primary outcome was clinical success, defined as the absence of endoleak on post-procedural ultrasonography at 6-weeks, provided the procedure was successfully completed. Other outcomes included clinical success at 1-year, aneurysm size, rupture and aneurysm-related mortality.

RESULTS

Twelve patients with type-II endoleak and AAA sac growth received transcaval embolisation. Technical success was achieved in 91.7% of cases, in which both Onyx 34 and coils were deployed into the sac. Clinical success, defined as an absence of endoleak on ultrasonography 6-weeks after a technically successful procedure, was achieved in 66.7% of patients, none of whom had evidence of endoleak at 1-year post-procedure. In patients whom clinical success was achieved, there was a decrease in sac size during follow-up, from 72.5 ± 13.1 at 6-weeks to 66.0 ± 12.1 at 1-year post-procedure. Aneurysm sac size continued to enlarge if clinical success was not observed, with an average sac size of 72.0 ± 14.1 at 6-weeks increasing to 76.9 ± 15.2 at 1-year. No patients suffered AAA rupture or AAA-related mortality during follow-up.

CONCLUSIONS

This study reports a high technical and clinical success rate, with outcomes that could suggest that this procedure could induce sac regression.

Endovascular Repair of Spontaneous Rupture of Stent Graft Branch in Thoracoabdominal Aortic Aneurysm-Management, Case Study, and Review

Background: Stent-graft implantation is a widely recognized method for endovascular treatment of aortic aneurysms. In cases where the aneurysm involves the thoracic and abdominal aorta, repair including fenestrated and branched stent grafts provides a viable alternative. This approach, initially reserved for patients unsuitable for open surgery, has become preferred for anatomically appropriate thoracoabdominal aortic aneurysms. The Zenith t-Branch system has been extensively studied, demonstrating high technical success rates and acceptable mortality and morbidity. However, complications such as endoleaks, kinking, and stent-graft branch rupture remain significant challenges. Methods: We present the case of an 82-year-old male with a thoracoabdominal aortic aneurysm treated with endovascular aneurysm repair using the Zenith t-Branch. Four years post-implantation, he developed a spontaneous rupture of the stent-graft branch, leading to dangerous leakage and aneurysm sac enlargement. An urgent surgical intervention was performed, implanting additional Be-Graft into the damaged branch, restoring stent-graft continuity and revascularizing the superior mesenteric artery. Results: The procedure was completed successfully. We conducted a review of the latest literature on endovascular treatment of thoracoabdominal aortic aneurysms with particular emphasis on the possibility of repairing postoperative complications, especially endoleaks. Conclusions: While modern technologies have significantly improved outcomes, serious complications persist. Studies emphasize the importance of regular imaging follow-up for early complication detection and management. Continuous advancements in stent-graft technology aim to reduce complications further and improve outcomes. This case underscores the necessity of experienced operators in managing complex and rare complications and highlights the promising future of endovascular techniques in treating thoracoabdominal aortic aneurysms.

Endovascular Treatment of Type II Endoleaks: Update and Overview

Endoleaks are a common complication following endovascular aneurysm repair, despite EVAR being the preferred method for the repair of abdominal aortic aneurysms. Endoleaks are continued blood flow into the aneurysmal sac, or more broadly elevated pressure outside of the endograft, and are classified into five types based on the source of blood flow or elevated pressure. Type II endoleaks are the most common and are a result of retrograde flow to the sac most commonly from the inferior mesenteric artery or lumbar artery. Endovascular treatment options for type II endoleaks include transarterial, transcaval, translumbar, and transabdominal approaches. This review discusses the indication for endovascular treatment of type II endoleaks, the selection of approach, and technical considerations.

Early and Mid-Term Outcomes of Transcaval Embolization for Type 2 Endoleak after Endovascular Aortic Repair

Background: Among the endovascular approaches for the management of endoleak type 2 (EL 2), transcaval embolization (TCE) has shown encouraging outcomes. However, the literature is still limited. This study aimed to present the early and mid-term outcomes of TCE for EL 2 after endovascular aortic repair. Methods: A retrospective, single-center analysis of consecutive patients managed with TCE for EL 2 after standard or complex endovascular aortic repair, from August 2015 to March 2024, was conducted. The indication for TCE was the presence of an EL 2 related to ≥5 mm sac increase, compared to the first imaging after aneurysm exclusion or the smallest diameter during follow-up. Patients managed with TCE for other types of endoleaks were excluded. The primary outcomes were technical and clinical successes during follow-up. Results: Forty-three patients were included (mean age: 75.1 ± 6.0 years, 90.7% males). Technical success was 97.7%. Selective embolization was performed in 48.8% and non-selective in 51.2%. No death was recorded at 30 days. The estimated clinical success was 90.0% (standard error; SE: 6.7%) and the freedom from EL 2 was 89.0% (SE 6.4%) at 36 months. Cox regression analysis showed that the type of embolization (selective vs. non-selective), type of previous repair (f/bEVAR vs. EVAR), and use of anticoagulants did not affect follow-up outcomes. Reinterventions related to EL 2 were performed in 12.5%; three underwent an open conversion. Conclusions: TCE was related to high technical success and limited peri-operative morbidity, regardless of the type of initial endovascular aortic repair. Clinical success was encouraging with reinterventions for EL 2 affecting 12.5% of patients.

Transvenous Access for Emergent Thoracic and Thoracoabdominal Aortic Aneurysm Repair in Patients Without Femoral Access

PURPOSE

To describe the technique of transvenous access for emergent endovascular repair of thoracic and thoracoabdominal aneurysms exemplified with 2 cases.

TECHNIQUE

Transvenous access to the aorta is described as an alternative access method to deliver aortic endografts in emergency situations. A 68-year-old female patient with severely compromised iliac and subclavian artery access was treated for a ruptured extent V thoraco-abdominal aortic aneurysm with a t-Branch (Cook Medical, Bjaeverskov, Denmark) delivered through a transcaval access. To avoid severe aortocaval shunting a balloon-expandable covered stent was deployed through a carotid access due to severe bilateral subclavian ostial stenosis. A 71-year-old man with an acute type B aortic dissection and bilateral narrow long-segment stenting of the iliac arteries was treated with a physician-modified thoracic endovascular aortic repair using an arteriovenous fenestration created at the level of the common iliac artery. We describe the access creation by fenestration using a transseptal needle.

CONCLUSION

Transvenous access for thoracic and thoraco-abdominal aortic aneurysm repair is safe and feasible in selected emergent cases.

CLINICAL IMPACT

A transvenous approach may be helpful in selected patients when an endovascular repair needs to be performed but no arterial femoral access is available. This approach proved to be feasible even with large-bore introducer sheaths, taking its place in the armamentarium of the vascular surgeon for emergent complex endovascular aortic repairs.

Management of Endoleaks After Elective Infrarenal Aortic Endovascular Aneurysm Repair: A Review

Importance

Endovascular aneurysm repair (EVAR) is the dominant treatment strategy for abdominal aortic aneurysms, encompassing 80% of all repairs in the United States. Endoleaks are ubiquitous and affect 30% of patients treated by EVAR, potentially leading to sac enlargement and increased risk of rupture. The care of EVAR patients requires long-term surveillance by a multidisciplinary team. Accordingly, physicians should be familiar with the fundamentals of endoleak management to achieve optimal outcomes, including timely referral for remediation or providing counseling and reassurance when needed.

Observations

PubMed and the Cochrane database were searched for articles published between January 2002 and December 2022 in English, addressing epidemiology, diagnosis, and management of endoleaks after EVAR. Endoleaks can be detected intraoperatively or years later, making lifelong surveillance mandatory. Type I and III have the highest risk of rupture (7.5% at 2 years and 8.9% at 1 year, respectively) and should be treated when identified. Intervention should be considered for other types of endoleak when associated with aneurysm sac growth larger than 5 mm based on current guidelines. Type II endoleaks are the most common, accounting for 50% of all endoleaks. Up to 90% of type II endoleaks resolve spontaneously or are not associated with sac enlargement, requiring only observation. Although the risk of rupture is less than 1%, cases that require reintervention are challenging. Recurrence is common despite endovascular treatment, and rupture can occur without evidence of sac growth. Type IV endoleaks and endotension are uncommon, are typically benign, and primarily should be observed.

Conclusions and Relevance

Endoleak management depends on the type and presence of sac expansion. Type I and III endoleaks require intervention. Type II endoleaks should be observed and treated selectively in patients with significant sac expansion. Since endoleaks can appear any time after EVAR, at least 1 contrast-enhanced computed tomographic angiogram or duplex ultrasound by an experienced laboratory is recommended every 5 years.

Characterization and management of type II and complex endoleaks after fenestrated/branched endovascular aneurysm repair

INTRODUCTION

Endoleaks are more common after fenestrated/branched endovascular aneurysm repair (F/B-EVAR) than infrarenal EVAR secondary to the length of aortic coverage and number of component junctions. Although reports have focused on type I and III endoleaks, less is known regarding type II endoleaks after F/B-EVAR. We hypothesized that type II endoleaks would be common and often complex (associated with additional endoleak types), given the potential for multiple inflow and outflow sources. We sought to describe the incidence and complexity of type II endoleaks after F/B-EVAR.

METHODS

F/B-EVAR data prospectively collected at a single institution in an investigational device exemption clinical trial (G130210) were retrospectively analyzed (2014-2021). Endoleaks were characterized by type, time to detection, and management. Primary endoleaks were defined as those present on completion imaging or at first postoperative imaging, and secondary were those on subsequent imaging. Recurrent endoleaks were those that developed after a successfully resolved endoleak. Reinterventions were considered for type I or III endoleaks or any endoleak associated with sac growth >5 mm. Technical success defined as the absence of flow in the aneurysm sac at procedure conclusion and methods of intervention were captured.

RESULTS

Among 335 consecutive F/B-EVARs (mean ± standard deviation follow-up: 2.5 ± 1.5 years), 125 patients (37%) experienced 166 endoleaks (81 primary, 72 secondary, and 13 recurrent). Of these 125 patients, 50 (40% of patients) underwent 71 interventions for 60 endoleaks. Type II endoleaks were the most frequent (n = 100, 60%), with 20 identified during the index procedure, 12 (60%) of which resolved before 30-day follow-up. Of the 100 type II endoleaks, 20 (20%; 12 primary, 5 secondary, and 3 recurrent) were associated with sac growth; 15 (75%) of those with associated sac growth underwent intervention. At intervention, 6 (40%) were reclassified as complex, with a concomitant type I or type III endoleak. Initial technical success for endoleak treatment was 96% (68 of 71). There were 13 recurrences, all of which were associated with complex endoleaks.

CONCLUSIONS

Nearly half of the patients who underwent F/B-EVAR experienced an endoleak. The majority were classified as type II, with nearly a fifth associated with sac expansion. Interventions for a type II endoleak frequently led to reclassification as complex, with a concomitant type I or III endoleak not appreciated on computed tomography angiography and/or duplex. Further study is needed to determine if the primary treatment goal for complex aneurysm repair is sac stability or sac regression, as this would inform both the importance of properly classifying endoleaks noninvasively and the intervention threshold for managing type II endoleaks.

Midterm Outcomes of Endoleak Type 2 Embolization after Endovascular Aortic Aneurysm Repair Using a Neurointerventional Approach

BACKGROUND

Type 2 endoleaks (T2ELs) have been considered a benign condition and intervention is recommended when they are associated to sac expansion. The aim of this study was to report on T2EL embolization midterm outcomes, using neurointerventional material.

METHODS

A single-center retrospective analysis of consecutive patients treated with transarterial embolization, using neurointerventional material, for T2EL after standard endovascular aortic aneurysm repair (EVAR) between January 01, 2017 and July 30, 2022, was undertaken. Primary outcome was technical success and secondary outcome was T2EL recurrence during follow-up.

RESULTS

Twenty six patients [92.3% males, mean age 73.9 ± 7.7 years] were included. The median time between EVAR and T2EL diagnosis was 12 months (range: 1-84 months). In 38.5% of patients, T2EL was detected at first month after EVAR. The time to embolization was 18 months (range: 1-96 months). In 42.3% of cases, a patent inferior mesenteric artery was suspected to relate to T2EL formation while in 42.3% of cases, a lumbar artery. Twelve procedures (38.4%) were performed using coils and Onyx and 13 (50%), using only Onyx. Technical success was 84.6%. The mean follow-up was 24 months (range: 1-60 months), including 20 patients. In 30% of cases, an T2EL recurrence was detected. Three patients (11.5%) underwent secondary embolization.

CONCLUSIONS

Transarterial embolization for T2EL, using neurointerventional material, provided acceptable technical success and T2EL recurrence rates at 2 years of follow-up. Longer follow-up data would further estimate the durability of the technique.

A Novel Technique and Outcomes for Transcaval Endoleak Embolization

BACKGROUND

Strategies for embolization of type 2 endoleaks include translumbar, transgraft, transarterial, and transcaval approaches. The transcaval approach is limited by an inconsistent ability to access the aortic sac and the risk of puncturing and damaging the endograft or adjacent structures. We describe a novel technique for caval to aortic aneurysm sac access and report early outcomes.

METHODS

A retrospective review of all patients who underwent transcaval embolization (TCE) at a tertiary referral center. From March 2019 to June 2021, 12 patients were identified to have undergone a novel approach to transcaval aortic sac access using a 0.014″ heavy weight tip wire guide and continuous current electrocautery to create the connection between the inferior vena cava and aortic aneurysm sac. The endoleak outflow vessel is then selectively embolized with coils or liquid embolic agents. When selective embolization was not possible, the aneurysm sac was instilled with liquid embolic agents to induce thrombosis.

RESULTS

Twelve patients underwent transcaval embolization using this method over the 3-year period. The average patient age was 79.2 ± 6.2 years and 10/12 (83.3%) were male. A high rate of comorbidities was noted in the cohort. Transcaval access into the aortic sac was achieved in all patients, while selective cannulation of outflow vessels was accomplished in 2/12 (16%) target vessels. Of these, both cases had vessels embolized using detachable coils and liquid embolic agents. Nonselective embolization was performed using liquid embolic and thrombotic agents in the other 10/12 cases. There was one perioperative complication of minor bleeding (1/12, 8.3%). Two patients were observed in intensive care unit for back pain. A persistent endoleak was identified on postoperative imaging performed at 30 days in 4/12 (33.3%) patients. Sac enlargement > 5 mm following TCE was observed in 3/12 (25%) patients. Three patients underwent open conversion with endovascular aneurysm repair explant. One patient was explanted at 1 month after failure to embolize the endoleak flow channel using TCE. A second was explanted for persistent endoleak found to be a Type IIIb with aortic diameter growth > 5 mm at 15-month follow-up. The third explant was performed for aortic sac infection at 4 months postprocedure without endoleak.

CONCLUSIONS

TCE is an adjunctive technique to treat endoleaks in patients who have either failed transarterial or translumbar access. An electrified 0.014″ chronic total occlusion wire technique for transcaval access to the aortic sac for endoleak embolization can be successful in all cases without significant acute morbidity or mortality. The transcaval approach is still limited by ability to steer catheters and microcatheters into the outflow vessels with a resultant persistent endoleak and eventual need for explant.