Significance of endoleaks after endovascular repair of abdominal aortic aneurysms: The EUROSTAR experience

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.

Serious Failure Modes After EVAR Are Device Specific

OBJECTIVES

Type I and III endoleaks following endovascular aneurysm repair (EVAR) can lead to catastrophic events that require major re-interventions. We reviewed our experience with aortic endograft re-interventions for type I and III endoleaks and other serious failures among different devices.

METHODS

We retrospectively reviewed patients with a prior EVAR who underwent open conversion (OC) or major endovascular intervention (MEI) (re-lining, cuff/limb extension, parallel graft) for type I/III endoleaks at our institution from 2002 to 2019. Baseline characteristics, procedural details, re-interventions, and outcomes were collected.

RESULTS

A total of 229 patients (194 men) underwent re-interventions for type I and III endoleaks after EVAR (90 OC, 139 MEI) for devices implanted between 1997 and 2019. Average age at re-intervention was 78±8.5 years. A total of 135 (59%) were implanted at our institution, whereas 93 (41%) were referred. Median time to re-intervention was 4 years with 25% to 75% interquartile range (IQR) of 2.2-6.6 years. There was no significant difference in baseline demographics or type of re-interventions (OC/MEI) between device types. 42/229 (18%) presented with ruptured aneurysms, 20/229 (9%) were symptomatic, whereas the rest presented with asymptomatic radiographic findings. Type 1A endoleak was present in 146/229 (63.8%-72 with proximal migration), type IB in 46/229 (20.1%), type IIIA in 37/229 (16.6%), type IIIB in 15/229 (6.5%), and persistent aneurysm sac growth with no radiographic evidence of an endoleak in 6/229 (2.6%). Devices included most commercial products: AFX, Excluder, AneuRx, Ancure, Endurant, and Zenith. A smaller number of investigational devices accounted for the rest. Type 1A endoleak was the most common indication for re-intervention among all devices except for AFX and ancure devices, proximal migration was a frequent presentation with AneuRx. AFX devices more frequently presented with a type III and ancure devices more frequently presented with a type IB endoleak.

CONCLUSIONS

Serious failure modes after EVAR differ between endografts and occur throughout the follow-up period. This is important to guide targeted interrogation of surveillance studies and follow-up schedules, even for discontinued devices, as well as comparisons between various series and estimation of EVAR failure rates.

CLINICAL IMPACT

Surveillance after EVAR is critical for long term success of the repair, understanding of the differential modes of failure of every graft available is important in the longitudinal evaluation of these endografts. Equally important is the understanding of the modes of failure of legacy endografts that are no longer on the market but still being followed, in order to be able to tailor a surveillance regiemn and the evntual repair if needed.

OnyxTMGel or Coil versus Hydrogel as Embolic Agents in Endovascular Applications: Review of the Literature and Case Series

This review focuses on the use of conventional gel or coil and "new" generation hydrogel used as an embolic agent in endovascular applications. In general, embolic agents have deep or multidistrict vascular penetration properties as they ensure complete occlusion of vessels by exploiting the patient's coagulation system, which recognises them as substances foreign to the body, thus triggering the coagulation cascade. This is why they are widely used in the treatment of endovascular corrections (EV repair), arteriovenous malformations (AVM), endoleaks (E), visceral aneurysms or pseudo-aneurysms, and embolisation of pre-surgical or post-surgical (iatrogenic) lesions. Conventional gels such as Onyx or coils are now commercially available, both of which are frequently used in endovascular interventional procedures, as they are minimally invasive and have numerous advantages over conventional open repair (OR) surgery. Recently, these agents have been modified and optimised to develop new embolic substances in the form of hydrogels based on alginate, chitosan, fibroin and other polymers to ensure embolisation through phase transition phenomena. The main aim of this work was to expand on the data already known in the literature concerning the application of these devices in the endovascular field, focusing on the advantages, disadvantages and safety profiles of conventional and innovative embolic agents and also through some clinical cases reported. The clinical case series concerns the correction and exclusion of endoleak type I or type II appeared after an endovascular procedure of exclusion of aneurysmal abdominal aortic (EVAR) with a coil (coil penumbra released by a LANTERN microcatheter), the exclusion of renal arterial malformation (MAV) with a coil (penumbra coil released by a LANTERN microcatheter) and the correction of endoleak through the application of Onyx 18 in the arteries where sealing by the endoprosthesis was not guaranteed.

Endotension Following Endovascular Aneurysm Repair: Retrospective Review of Treatment and Clinical Outcome

Purpose

: Endotension is a rare late complication characterized by an increase in sac size without any type of endoleak following endovascular aortic aneurysm repair (EVAR). Due to its rarity, few studies have demonstrated the mechanism behind and the management of endotension. In this study, we aimed to better understand the treatment and the long-term outcome of endotension in a single-center cohort.

Materials and Methods

: This study was designed for a retrospective review of the patients diagnosed with endotension between January 2006 and December 2017. The study patients were categorized into two groups (primary versus secondary) based on the presence of any type of endoleak before the diagnosis of endotension. We collected data related to endotension treatment, intraoperative findings, and long-term outcomes.

Results

: In a cohort of 15 patients diagnosed with endotension following EVAR, eight were classified into the primary endotension (PE) group without prior endoleak, and seven exhibited secondary endotension (SE). Among the eight PE patients, endovascular intervention for a preemptive purpose was conducted in six patients; however, three (50%) showed continuous sac expansion and finally received open conversion. Overall, eight patients (five in PE and three in SE) underwent open conversion, and one (12.5%) presented with an undetected endoleak during the operative findings. Postoperative morbidity was observed in three patients with no operative mortality.

Conclusion

: Endotension can be managed initially through simple observation for changes on serial images, along with preemptive endovascular intervention. However, surgical intervention should be considered for patients with specific indications including continuous aneurysm sac enlargement, presence of symptoms, suspicions of migration of stent-graft with endoleak, and infection.

Editor's Choice -- Type IIIb Endoleaks: Fabric Perforations of Explanted New Generation Endoprostheses

OBJECTIVE

To analyse explanted endografts (EGs) and describe fabric degradation responsible for type IIIb endoleaks.

METHODS

As part of the European collaborative retrieval programme, 32 EGs with fabric defects on macroscopic evaluation were selected. The explanted EGs were processed and studied based on the ISO 9001 certified standard protocol. It includes instructions on the collection, transportation, cleaning, and examination of explanted material. The precise analysis was performed with a digital microscope of 20 - 200 times magnification. Possible perforation mechanisms were assessed in stress tests.

RESULTS

The median time to explantation of the 32 EGs was 54 months. The explants included 65 separate EG modules, with 46 (70.8%) having a combined 388 fabric perforations. Each EG had a median of 4.79 mm2 (interquartile range [IQR] 9.86 mm2) of cumulated hole area (an average of 0.13% of an EG's area). There were 239 (61.6%) expanded polytetrafluoroethylene (ePTFE; 11 EGs) and 149 (38.4%) polyethylene terephthalate (PET; 21 EGs) fabric ruptures, with no difference in hole distribution between these types of material. Overall, 126 (32.5%) stent related and 262 (67.5%) non-stent related fabric perforations were identified. Perforations caused by fabric fatigue in ePTFE (151, 63.2%) and material kinking in PET (41, 27.5%) were the most common. The stent related perforations were larger in size (0.80 mm2) than non-stent related perforations (0.19 mm2); p < .001. Wider interstent spaces and prolonged implantation duration were associated with an increased risk of stent related perforation development; p < .001 and p = .004, respectively. Large stent related perforations were also detected in the short term, suggesting mechanical issues as underlying causes.

CONCLUSION

The fabric of EGs may degrade and lead to the development of perforations. The largest perforations are stent related. Their occurrence and size depend on the implantation time and the EG shape affected by arterial tortuosity. The conclusions are limited to the samples from a select explant group.

CIRSE Standards of Practice on Management of Endoleaks Following Endovascular Aneurysm Repair

BACKGROUND

Endoleaks represent the most common complication after EVAR. Some types are associated with ongoing risk of aneurysm rupture and necessitate long-term surveillance and secondary interventions.

PURPOSE

This document, as with all CIRSE Standards of Practice documents, will recommend a reasonable approach to best practices of managing endoleaks. This will include imaging diagnosis, surveillance, indications for intervention, endovascular treatments and their outcomes. Our purpose is to provide recommendations based on up-to-date evidence, updating the guidelines previously published on this topic in 2013.

METHODS

The writing group was established by the CIRSE Standards of Practice Committee and consisted of clinicians with internationally recognised expertise in endoleak management. The writing group reviewed the existing literature performing a pragmatic evidence search using PubMed to select publications in English and relating to human subjects up to 2023. The final recommendations were formulated through consensus.

RESULTS

Endoleaks may compromise durability of the aortic repair, and long-term imaging surveillance is necessary for early detection and correct classification to guide potential re-intervention. The majority of endoleaks that require treatment can be managed using endovascular techniques. This Standards of Practice document provides up-to-date recommendations for the safe management of endoleaks.

Improved Detection of Endoleaks in Virtual Monoenergetic Images in Dual-Energy CT Angiography Following EVAR

OBJECTIVES

The objective of this prospective study was to evaluate the virtual monoenergetic images (VMI) and virtual noncontrast (VNC) phase in the detection of endoleaks after endovascular abdominal aortic repair (EVAR). The potential dose reduction of abbreviated examination protocols was calculated.

MATERIALS AND METHODS

Ninety-seven patients after the EVAR procedure were enrolled in this study. An initial single-source noncontrast acquisition was followed by two dual-energy acquisitions (arterial and 60 s delayed). Fast-kVp switching scanner was used. VNC images were reconstructed from the delayed phase. First examination session (reference) included a full triphasic study protocol consisting of true noncontrast (TNC) images and two postcontrast phases, the latter ones presented as classical polyenergetic reconstructions. Reading sessions II and III were performed by two independent and blinded readers evaluating VMIs in abbreviated protocols-biphasic (VNC + arterial, delayed phase), monophasic (VNC + delayed phase). The diagnostic accuracy of sessions II and III was calculated.

RESULTS

The calculated sensitivity of the biphasic protocol with the use of VMIs in endoleak detection was 100%, with a statistically significant increase in the number of endoleaks detected in comparison with the reference study. The monophasic protocol showed 83.33% sensitivity. The use of abbreviated examination protocols led to a decrease in the mean effective dose (ED) of 23.28% (biphasic protocol) and 61.37% (monophasic protocol).

CONCLUSION

The use of VMIs increases the number of endoleaks diagnosed with a possible radiation reduction by up to ¼ (biphasic protocol). Further reduction to a monophasic protocol leads to over 60% dose reduction but with a decrease in diagnostic accuracy.

Use of the Endoleak-to-Aortic Density Ratio to Distinguish Direct Endoleaks from Indirect Endoleaks after Endovascular Aortic Aneurysm Repair

PURPOSE

To define criteria to distinguish direct (type 1 or 3) from indirect endoleaks (type 2) in the arterial phase of contrast-enhanced computed tomography (CT) scans in patients with abdominal aortic aneurysms treated with endovascular aortic repair.

MATERIALS AND METHODS

This retrospective study was conducted from January 2009 to October 2020 and included consecutive patients treated endovascularly for a direct endoleak or an indirect endoleak associated with an enlarging aneurysm. The following characteristics were evaluated using contrast-enhanced CT: location, size, contact with the endograft, density, morphologic criteria, collateral artery enhancement, and endoleak-to-aortic density ratio. Statistical analysis included the Mann-Whitney U test, Pearson χ2 test, Fisher exact test, receiver operating characteristic curve analysis, and multivariable logistic regression.

RESULTS

Contrast-enhanced CT scans from 71 patients (87% men), who presented with 87 endoleaks (44 indirect and 43 direct endoleaks), treated by endovascular techniques were analyzed. Using visual criteria, 56% of the endoleaks were not characterizable as direct or indirect. An endoleak-to-aortic density ratio of >0.77 could properly distinguish direct from indirect endoleaks, with a theoretical accuracy of 98% (area under the receiver operating characteristic curve, 0.99), sensitivity of 95%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 96%.

CONCLUSION

An endoleak-to-aortic density ratio of >0.77 in the arterial phase of contrast-enhanced CT could be a strong discriminant of a direct-type endoleak.

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.

Incidence, Risk Factors, and Prognostic Impact of Type Ib Endoleak Following Endovascular Repair for Abdominal Aortic Aneurysm: Scoping Review

OBJECTIVE

The primary objectives of this scoping review were to assess the rate of and risk factors for type Ib endoleak and to evaluate the extent of the evidence base that links type Ib endoleak to short and long term outcomes in patients undergoing endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA).

METHODS

Potentially eligible studies were searched in the Cochrane Central Register of Controlled Trials, MEDLINE, Web of Science Core Collection, SciELO Citation Index, Russian Science Citation Index, and KCI-Korean Journal Database. A scoping review was performed according to PRISMA extension for Scoping Reviews.

RESULTS

A total of 27 articles (four prospective registries and 23 retrospective cohort studies) dealing with type Ib endoleak were included in the final analysis. The number of patients reported on was 7 197, with follow up ranging between 12 months and 93 months. The reported frequency of type Ib endoleak in patients treated with EVAR ranged from 0% to 8%, Patient and or procedure related factors associated with risk of type Ib endoleak were (1) common iliac artery (CIA) diameter ˃ 18 mm requiring use of flared stent graft limbs (FLs) ˃ 20 mm, (2) length of CIA landing zone ˂ 20 mm, (3) marked iliac tortuosity, and (4) large initial AAA diameter. Depending on the study, 50 - 100% of type Ib endoleaks were corrected by endovascular means, with a reported immediate technical success of 100% in the studies providing this information.

CONCLUSION

Type Ib endoleak after EVAR has been reported to occur in 0 - 8% of cases. Several anatomical features, including CIA diameter ˃ 18 mm or requiring the use of FLs ˃ 20 mm, length of CIA landing zone ˂ 20 mm, marked iliac tortuosity, and large initial AAA diameter, could increase the risk of type Ib endoleak and may require alternative therapeutic options and or more stringent follow up. Therefore, this updated scoping review provides a comprehensive summary of the frequency, risk factors, prognosis, and treatment of type Ib endoleaks, and has identified knowledge gaps in the literature to guide further studies.

The Impact of Proximal Neck Anatomy on the 5-Year Outcomes Following Endovascular Aortic Aneurysm Repair With the Ovation Stent Graft

PURPOSE

Hostile proximal neck anatomy has historically been associated with worse outcomes for endovascular aortic aneurysm repair (EVAR) of abdominal aortic aneurysms (AAA). We investigated the impact of proximal neck anatomy on the outcomes following EVAR with the Ovation abdominal stent graft (Endologix, Irving, Calif).

METHODS

We used prospectively collected data from the Effectiveness of Custom Seal with Ovation: Review of the Evidence database, compromised of pooled data from 6 clinical trials and the European Post-Market Registry of patients undergoing elective infrarenal EVAR (2009-2017). We investigated the impact of short neck length (<10 mm), wide neck diameter (≥28 mm), reverse taper shape (>10%), and neck angulation (>45°) on the outcomes. The primary outcome was type IA endoleak. Secondary outcomes included any type I/III endoleak, sac expansion, aneurysm-related reinterventions, and all-cause and aneurysm-related mortality, and a combined endpoint of type IA endoleak, graft migration, AAA-related reintervention, conversion, and aneurysm rupture. We used Kaplan-Meier analysis and Cox proportional hazards models to estimate the 30 day and 5 year rates and assess univariate and risk-adjusted differences.

RESULTS

Of the 1020 patients, 60 patients had a short neck, 113 had a wide neck diameter, 279 were reverse taper shaped, and 99 had neck angulation >45°. Wide proximal neck was associated with higher 5 year type IA endoleak estimates compared with favorable neck anatomy (7.1% vs 4.3%; p=0.02). No association with 5 year type IA endoleak was found for short neck length (1.7% vs 4.3%; p=0.52), reverse taper shape (3.2% vs 4.3%; p=0.99), or neck angulation (6.1% vs 4.3%; p=0.13). A wide neck diameter compared with favorable anatomy was also associated with higher 5 year estimates of graft migration (3.8% vs 0.4%; p=0.03) and the combined neck-related adverse outcome endpoint (16% vs 9.5%; p=0.002). The estimates of aneurysm sac expansion, rupture, and overall and aneurysm-related mortality were similar between the hostile proximal neck anatomy cohorts and favorable anatomy.

CONCLUSION

Wide proximal neck is associated with higher 5 year type IA endoleak rates for patients treated with the Ovation stent graft. However, short neck length, reverse taper shape, and neck angulation are not associated with higher 5 year type IA endoleak rates.

CLINICAL IMPACT

Hostile proximal neck anatomy has historically been associated with worse outcomes for endovascular aortic aneurysm repair of abdominal aortic aneurysms. The Ovation stent graft platform uses a different proximal sealing method using a polymer inflatable ring, aiming to improve sealing between the graft and aortic wall. This study demonstrated that short, angulated, and reverse taper-shaped neck anatomy did not result in increased type IA endoleak estimates in patients treated with the Ovation stent graft platform. Potentially, the different sealing mechanisms played a role in mitigating the historically worse outcomes in patients with short, angulated, and reverse taper-shaped neck anatomy.

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

OBJECTIVE

To assess the real world incidence, outcomes, and risk factors of type III endoleaks (TIIIEL) after endovascular aneurysm repair (EVAR).

METHODS

This was a single centre, retrospective, observational, cohort study. All patients with abdominal aortic aneurysms (AAAs) receiving EVAR between 1994 and 2020 were collected prospectively and reviewed. The primary outcome was the cumulative incidence and impact on survival of TIIIELs, either defined as disconnections of modular graft components (TIIIaEL) or fabric defects (TIIIbEL). Secondary outcomes included risk factor analysis evaluating baseline morphological and stent graft details, as well as a comparison of TIIIaEL and TIIIbEL.

RESULTS

In total, 2 565 EVARs were performed and 95 (3.7%) TIIIELs were diagnosed at a median interval of 49.5 months (interquartile range [IQR] 19.4, 67.6). Estimated TIIIEL incidence at five years was 6.8%, 2.2%, and 3.6% for first and second generation, third and fourth generation, and fifth and sixth generation, respectively. The survival rate in patients without any high flow endoleak was 88.0%, 67.9%, 56.9%, and 52.1%, while in TIIIEL patients it was 98.6%, 77.2%, 49.8%, and 32.3% at one, five, 10, and 15 years, respectively (p = .77). The distribution of TIIIaEL and TIIIbEL was 70.5% and 29.5%, respectively. TIIIbEL received a higher rate of open treatment (28.6% vs. 7.5%; p = .005) and device or procedure related re-interventions (35.7% vs. 13.4%; p = .013). Fourteen (15.4%) recurrent TIIIELs were diagnosed at a median of 16.8 months (IQR 7.6, 32.1). Old generation endografts (hazard ratio [HR] 2.1, 95% confidence interval [CI] 1.3 - 3.4; p = .002) and non-proprietary extensions (HR 3.6, 95% CI 1.9 - 6.8; p < .001), and angulated and calcified aneurysm neck (HR 3.6, 95% CI 1.2 - 10.6; p = .017) were risk factors for TIIIEL. Every 10 mm maximum AAA diameter increase presented a 1.4 fold higher risk of TIIIEL.

CONCLUSION

TIIIEL is a severe condition that is often fatal if left untreated. Old endografts, the implantation of non-proprietary extensions, large AAAs, and angulated and calcified necks are risk factors for TIIIEL that require careful follow up due to the high rate of recurrence.

Endovascular Aneurysm Sac Embolization for Treatment of Ruptured Aneurysms in the Aortoiliac Segment Using N-Butyl-Cyanoacrylate

Background Aneurysmal rupture in the aortoiliac segment is a severe, life-threatening condition. Nowadays, in addition to surgical treatment, the implantation of a covered stent graft constitutes a feasible, minimally invasive treatment option. A novel approach is the add-on of transarterial aneurysm sac embolization with N-butyl-cyanoacrylate (NBCA). Here, we report our experience of performing this add-on embolization procedure after endovascular aneurysm repair for complex ruptured aneurysms of the aortoiliac segment. Material and Methods We describe six patients (mean age of 75.2 years; all male) with ruptured aneurysms in the visceral aortic and aortoiliac segment in whom a high-volume transarterial aneurysm sac embolization was performed as an add-on therapy to the implantation of an aortic prosthesis. The aim of this add-on intervention was to achieve the definite embolization of the aneurysmal rupture site and to ensure the best possible aneurysmal sealing. We report the feasibility, technical success, and considerations of using NBCA as well as clinical and follow-up imaging results, given their availability. Results Technical success was achieved in all cases. Clinical success was achieved in four cases. No periprocedural complications or reinterventions were reported. The mean full procedure time was 107.8 min. The mean radiation dose was 12,966.1 cGy/cm2. A mean amount of 10.7 mL of NBCA mixed with lipiodol in a 1:3 to 1:5 ratio was used for all patients. Available follow-up imaging up to 36 months after the procedure showed no aneurysm progression or endoleaks. In two patients, the NBCA cast had almost fully dissolved over the course of follow-up. Conclusions Our study underscores the notion that aneurysm sac embolization using high volumes of NBCA with ethiodized oil as an embolic agent is a feasible and add-on treatment option for optimizing the exclusion of the aneurysm from patients with ruptured aneurysms in the aortoiliac segment.

Routine Inferior Mesenteric Artery Embolisation is Unnecessary Before Endovascular Aneurysm Repair

OBJECTIVE

A type II endoleak is the most common complication during surveillance after endovascular aneurysm repair (EVAR), and a patent inferior mesenteric artery (IMA) is a known risk factor for an endoleak. The effect of routine IMA embolisation prior to EVAR on overall outcome is unknown. The aim of the study was to compare two strategies: routine attempted IMA embolisation prior to EVAR (strategy in centre A) and leaving the IMA untouched (strategy in centre B).

METHODS

Patients were treated with EVAR in two centres during the period 2005 - 2015, and the data were reviewed retrospectively. The primary endpoints were re-intervention rate due to type II endoleaks and the late IMA embolisation rate. Secondary endpoints included EVAR related re-intervention, sac enlargement, aneurysm rupture, and open conversion rates.

RESULTS

Strategy A was used to treat 395 patients. The IMA was patent in 268 (67.8%) patients, and embolisation was performed in 164 (41.5%). The corresponding figures for strategy B were 337 patients with 279 (82.8%) patent IMAs, two (0.6%) of which were embolised. The mean duration of follow up was 70 months for strategy A and 68.2 months for strategy B. The re-intervention rates due to a type II endoleak were 12.9% and 10.4%, respectively (p = .29), with no significant difference in the rate of re-interventions to occlude a patent IMA (2.0% and 4.7%, respectively; p = .039). The EVAR related re-intervention rate was similar, regardless of strategy (24.1% and 24.6%, respectively; p = .93). Significant sac enlargement was seen in 20.3% of cases treated with strategy A and in 19.6% treated with strategy B (p = .82). The rupture and conversion rates were 2.5% and 2.1% (p = .69) and 1.0% and 1.5% (p = .40), respectively.

CONCLUSION

The strategy of routinely embolising the IMA does not seem to yield any significant clinical benefit and should therefore be abandoned.

Internal Iliac Artery Embolization within EVAR Procedure: Safety, Feasibility, and Outcome

BACKGROUND

This study is focused on Internal Iliac Artery (IIA) embolization in patients undergoing Endovascular Aneurysm Repair (EVAR). Our aims were: to establish the feasibility of the procedure; to assess the presence of endoleak (EL) and increase in the size of the sac at follow-up; to define the need for reintervention; and to evaluate mortality rate.

METHODS

In this retrospective single-center study, EVAR-treated patients with an embolization of IIA were chosen. Coils and vascular plug were used as embolizing agents.

RESULTS

A total of 49 participants were enrolled in the study (48 men and one woman) with a median age of 76 ± 12 years. Patients had no early EL in 87.75% of cases, 8.16% had type 1a EL, 2.04% type 1b EL, and 2.04% type 2 EL, with a comprehensive technical success of 95.91%. In the follow-up, at 1 month 72.22% remained without EL, at 6 months 70.97%, and at 1 year 81.48%. In the same period, the trend of type 1 EL was 5.56% (1 month), 3.23% (6 months), and 0% (1 year). For EL type 2: 22.22% at 1 month, 25.81% at 6 months, and 16.7% at 1 year. The overall mortality was 35.58% and the re-intervention rate was 16.33%.

CONCLUSIONS

IIA embolization is a feasible and safe procedure. The presence of EL is not superior to EVAR procedures that do not involve embolization.

Contrast-enhanced US Evaluation of Endoleaks after Endovascular Stent Repair of Abdominal Aortic Aneurysm

Ruptured abdominal aortic aneurysm (AAA) carries high morbidity and mortality. Elective repair of AAA with endovascular stent-grafts requires lifetime imaging surveillance for potential complications, most commonly endoleaks. Because endoleaks result in antegrade or retrograde systemic arterialized flow into the excluded aneurysm sac, patients are at risk for recurrent aneurysm sac growth with the potential to rupture. Multiphasic CT has been the main imaging modality for surveillance and symptom evaluation, but contrast-enhanced US (CEUS) offers a useful alternative that avoids radiation and iodinated contrast material. CEUS is at least equivalent to CT for detecting endoleak and may be more sensitive. The authors provide a general protocol and technical considerations needed to perform CEUS of the abdominal aorta after endovascular stent repair. When there are no complications, the stent-graft lumen has homogeneous enhancement, and no contrast material is present in the aneurysm sac outside the stented lumen. In patients with an antegrade endoleak, contrast material is seen simultaneously in the aneurysm sac and stent-graft lumen, while delayed enhancement in the sac is due to retrograde leak. Recognition of artifacts and other potential pitfalls for CEUS studies is important for examination performance and interpretation. Online supplemental material is available for this article. ^©RSNA, 2022.

Systematic review and network meta-analysis of pre-emptive embolization of the aneurysm sac side branches and aneurysm sac coil embolization to improve the outcomes of endovascular aneurysm repair

Objective

Previous reports have revealed a high incidence of type II endoleak (T2EL) after endovascular aneurysm repair (EVAR). The incidence of T2EL after EVAR is reduced by pre-emptive embolization of aneurysm sac side branches (ASSB) and aneurysm sac coil embolization (ASCE). This study aimed to investigate whether different preventive interventions for T2EL were correlated with suppression of aneurysm sac expansion and reduction of the re-intervention rate.

Methods

The PubMed, Web of Science, MEDLINE and Embase databases, and conference proceedings were searched to identify articles on EVAR with or without embolization. The study was developed in line with the Participants, Interventions, Comparisons, Outcomes, and Study design principles and was conducted and reported in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. We used network meta-analysis based on multivariate random-effects meta-analysis to indirectly compare outcomes of different strategies for embolization during EVAR.

Results

A total of 31 studies met all inclusion criteria and were included in the qualitative and quantitative syntheses. The included studies were published between 2001 and 2022 and analyzed a total of 18,542 patients, including 1,882 patients who received prophylactic embolization treatment during EVAR (experimental group) and 16,660 who did not receive prophylactic embolization during EVAR (control group). The effect of pre-emptive embolization of the inferior mesenteric artery (IMA) (IMA-ASSB) in preventing T2EL was similar (relative risk [RR] 1.01, 95% confidence interval [CI] 0.38–2.63) to the effects of non-selective embolization of ASSB (NS-ASSB) and ASCE (RR 0.88, 95% CI 0.40–1.96). IMA-ASSB showed a better clinical effect in suppressing the aneurysm sac expansion (RR 0.27, 95% CI 0.09–2.25 compared with NS-ASSB; RR 0.93, 95% CI 0.16–5.56 compared with ASCE) and reducing the re-intervention rate (RR 0.34, 95% CI 0.08–1.53 compared with NS-ASSB; RR 0.66, 95% CI 0.19–2.22 compared with ASCE). All prophylactic embolization strategies improved the clinical outcomes of EVAR.

Conclusion

Prophylactic embolization during EVAR effectively prevents T2EL, suppresses the aneurysm sac expansion, and reduces the re-intervention rate. IMA embolization demonstrated benefits in achieving long-term aneurysm sac stability and lowering the risk of secondary surgery. NS-ASSB more effectively reduces the incidence of T2EL, while IMA embolization alone or in combination with ASCE enhances the clinical benefits of EVAR. In addition, as network meta-analysis is still an indirect method based on a refinement of existing data, more studies and evidence are still needed in the future to establish more credible conclusions.

Type III Endoleak Leading to Aortic Rupture After Endovascular Repair

Endovascular treatment of abdominal aortic aneurysm concerns the introduction of aortic endoprosthesis which aims to isolate aneurysm from the circulation. The leading complication of this technique is the endoleak which is defined by the persistence of blood flow within the aneurysm sac. The main risk is the rupture of the aorta which can jeopardize the vital prognosis of patient. White classification defines five types of endoleaks. Type III is secondary either to a disconnection between the components of the endoprosthesis (type IIIA) or to material damage (type IIIB). This type presents a particularly high risk of aortic rupture. Endovascular approach is the treatment of choice for this type of endoleaks through stent-grafts implantation. Type III endoleak may appear at any time after endovascular aortic aneurysm repair (EVAR). Although the frequency of endoleak after EVAR has been reduced after improvement and development of stent-graft systems, there are still many improvements and additions expected to improve the prognoses for patients after EVAR. Our case is an 80-year-old patient, who received an EVAR in 2012 for his abdominal aortic aneurysm, admitted to our vascular surgery department for a type III endoleak, for which he benefited from an endovascular treatment by placement of stent-grafts.

Type IIIb endoleak due to stent suture line fabric breakage in the Endurant stent graft: a case report

Background

Early type IIIb endoleak is a very rare complication of endovascular aneurysm repair (EVAR).

Case presentation

An 87-year-old man was diagnosed with infrarenal abdominal aortic aneurysm. The patient underwent EVAR using the Endurant stent graft. Postoperative color duplex ultrasound revealed a regular row of pulsatile blood flow from the main body and left leg. The blood flow appeared to be bleeding from the stent suture lines because of its regularity. Type IIIb endoleak was suspected due to stent suture line fabric breakage but was not treated surgically or endovascularly because of the patient’s poor general health status. Six months later, contrast-enhanced CT demonstrated a deformation and enlargement of the aneurysm sac as well as an oozing of the contrast medium on the main body and left limb. Thereafter, he died of a subdural hematoma due to a fall. Autopsy showed no visible abnormal erosion or holes on the graft fabric, suggesting that suture line fabric breakage may have existed during the manufacturing process.

Conclusions

Although rare, type IIIb endoleaks can occur even in the perioperative period after EVAR. Early type IIIb endoleaks may not resolve spontaneously and should be treated promptly, if possible.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40792-022-01415-8.

Persisting Type 2 Endoleaks Following EVAR for AAA Are Associated With AAA Expansion

PURPOSE

To determine the evolution of abdominal aortic aneurysm (AAA) diameter in the presence of persisting type 2 endoleaks (pEL2) following endovascular abdominal aortic aneurysm repair (EVAR).

MATERIALS AND METHODS

This is a retrospective, single-center, case-control study. All patients with pEL2 (pEL2 group, persisting for > 12 months) between 2004 and 2018 were identified and compared with a 1:1 age- and gender-matched control with no endoleak (control group). Primary outcome measures were freedom from AAA expansion and freedom from AAA shrinkage over time. AAA diameter measurements were performed on computed tomography angiography (CTA). Secondary outcome measures were survival, AAA-related mortality, reinterventions for pEL2, incidence of secondary type 1 endoleaks (EL1), and infrarenal aortic branch vessel anatomy.

RESULTS

A total of 773 patients were treated with EVAR for AAA between 2004 and 2018. Of them, 286 patients demonstrated type 2 endoleaks (EL2) in postoperative CTA or intraoperative angiography (37%). Forty-five of 286 EL2 (15.7%) were pEL2 (pEL2 group). Freedom from AAA expansion in the pEL2 group was 100%, 96.7%, 85.2%, and 54.3% after 1, 2, 3, and 4 years, respectively, compared with 100% after 1, 2, 3, and 4 years in the control group (p<0.01). Freedom from AAA shrinkage in the pEL2 group after 1, 2, 3, and 4 years was 95.5%, 90.4%, 90.4%, and 79.1%, respectively, compared with 86.7%, 34.8%, 19.3%, and 19.3% in the control group (p<0.01). Overall survival at 1, 2, 3, and 4 years was 100%, 97.6%, 95.0% and 95.0% in the pEL2 group and 100% at 1, 2, 3, and 4 years in the control group (p=0.17). There were no AAA-related deaths in either group. Patients with pEL2 had a significantly increased number of infrarenal aortic branches (p<0.05, respectively). Eighteen patients (40.0%) in the pEL2 group underwent 34 reinterventions for pEL2, with a median follow-up (FU) of 925 days (0-4173). Clinical success was achieved in 9 patients (50.0%). Four patients (8.9%) with pEL2 developed secondary EL1 after a median FU of 1278 days (662-2121).

CONCLUSION

pEL2 are associated with AAA expansion during midterm FU. Further studies are warranted to evaluate the association of AAA expansion due to pEL2 with clinical outcomes to allow recommendations with regard to treatment indications.

Late Type III Endoleaks Are Common in Early Generation Endologix AFX Stent Grafts

INTRODUCTION

Early generation Endologix AFX Endovascular AAA Stent Graft devices are at risk of developing type IIIa (intercomponent/overlap-related) as well as type IIIb (fabric tear) endoleaks over time. Current follow-up studies are limited to short (<24 months) and midterm (24-48 months) reports. The purpose of this study was to identify the incidence of type III endoleaks associated with these endografts over a long-term follow-up (>4 years) period and discuss current management strategies.

METHODS

A retrospective single institution cohort analysis of all Endologix AFX endografts implanted 10/2011-10/2016 was performed. Patient characteristics, imaging and follow-up were obtained via chart review. Type III endoleaks were characterized based on Computed tomography (CT) angiogram/operative findings and confirmed by 2 surgeons. Statistical Analysis was performed with SAS v9.4.

RESULTS

Sixty-three patients underwent AFX stent graft implantation for aneurysmal disease. 47 patients comprised the final cohort for analysis after exclusions were made for primary iliac aneurysms as well as off label use of the device (e.g., hypogastric snorkel) or primary occlusive indications. Average age was 73.3 years with longest follow-up 8.7 years (median 5.2). Most AAA (89.2%) were fusiform with initial median diameter 5.5cm. Initial 30-day mortality was 0%. Of the initial cohort, 10 (21.3%) type III endoleaks were treated, of which 6 (60%) were type IIIa and 4 (40%) were type IIIb. By time to event analysis at latest follow-up freedom from type 3 intervention was 48% at 8 years. Median time to type III endoleak discovery was 4.7 years (range 1.1 -7.2 years) an interval that was similar for type IIIa and type IIIb leak types, p=0.73. Patients with type III endoleaks had average sac growth of 1.3cm over the follow-up interval compared to a net decrease for patients without type III endoleaks, p<.0001. Of the 10 patients treated for type III leaks, 7 (70%) underwent complete endovascular re-lining, one (10%) had partial re-lining while 2 (20.0%) underwent open endograft explant with aortic graft reconstruction. Reintervention 30-day mortality was 0% for all approaches.

CONCLUSION

Early generation Endologix AFX stent grafts have a high rate of type III endoleaks, with freedom from type III leak <50% at 8-year follow-up. Most of these are not detected until several years (>4.5) after initial implantation, beyond the range of the follow-up interval of most published reports. Long-term imaging surveillance is critical and a low threshold for complete relining should be considered with any sign of sac enlargement, even if endoleak is not clearly demonstrated in patients with early generation Endologix AFX grafts.

Contemporary Management of Abdominal Aortic Aneurysms

PURPOSE OF REVIEW

Abdominal aortic aneurysms (AAA) can carry extremely high mortality rates and most will only present with symptoms with impending rupture. We present an overview of management of this disease process starting with screening, to medical management, surveillance and treatment options currently available, as well as those being studied for future use.

RECENT FINDINGS

Screening has been proven to reduce the mortality rate. There still remains a paucity of data to support medical therapies to help mitigate the rate of aneurysm growth and prevent rupture. However, on the topic of repair, there have been advancements in endovascular devices which have broadened the scope of treatment for patients with anatomy not amenable to standard endovascular repair or those who are not suitable candidates for open surgical repair. Appropriate surveillance, risk factor modification, and operative repair, when indicated, are the cornerstones of contemporary management of AAAs. Advancements in endovascular technologies have allowed us to treat more patients. Further research is warranted on non-operative medical therapies.

3D finite-element modeling of vascular adaptation after endovascular aneurysm repair

Aneurysm shrinkage is clinically observed after successful endovascular aortic aneurysm repair (EVAR). However, global understanding of post-operative aneurysm evolutions remains weak. In this work, we propose to study these effects using numerical simulation. We set up a 3D finite-element model of post-EVAR vascular adaptation within an open-source finite-element code, which was initially developed for growth and remodeling (G&R). We modeled the endograft with a set of uniaxial prestrained springs that apply radial forces on the inner surface of the artery. Constitutive equations, momentum balance equations, and equations related to the mechanobiology of the artery were formulated based on the homogenized constrained mixture theory. We performed a sensitivity analysis by varying different selected parameters, namely oversizing and compliance of the stent-graft, gain parameters related to collagen G&R, and the residual pressure in the aneurysm sac. This permitted us to evaluate how each factor influences post-EVAR vascular adaptation. It was found that oversizing, compliance or gain parameters have a limited influence compared to that of the residual pressure in the aneurysm sac, which was found to play a critical role in the stability of aneurysm after stent-graft implantation. An excessive residual pressure larger than 50 mmHg can induce a continuous expansion of the aneurysm while a moderate residual pressure below this critical threshold yields continuous shrinkage of the aneurysm. Moreover, it was found that elderly patients, with relatively lower amounts of remnant elastin in the arterial wall, are more sensitive to the effect of residual pressure. Therefore, these results show that elderly patients may present a higher potential risk of aortic sac expansion due to intra-aneurysm sac pressure after EVAR than younger patients.

The identification and management of the profunda femoris artery as a rare source of a late type II endoleak

Internal iliac artery aneurysms are found in 20% of abdominal aortic aneurysm cases, with a high mortality rate in the event of rupture. Type II endoleaks are a common complication after endovascular intervention. Transarterial or direct sac puncture techniques have superseded open surgical repair due to the challenging nature open surgery presents in accessing the feeding vessel(s). We describe the rare source of a late type II endoleak feeding from the profunda femoris in an 83-year-old man after fenestrated endovascular aortic aneurysm repair and concurrent embolization of the right internal iliac artery for treatment of a juxtarenal abdominal aortic aneurysm and internal iliac artery aneurysm.

Safety and Validity of the Proposed European Society for Vascular Surgery Infrarenal Endovascular Aneurysm Repair Surveillance Protocol: A Single Centre Evaluation

OBJECTIVE

Long term surveillance after endovascular aneurysm repair (EVAR) is essential to detect late complications, but there is variation in practice. The European Society for Vascular Surgery (ESVS) made a recommendation for a new surveillance protocol; one element involves risk stratifying patients depending on sac size reduction and presence of endoleak at their 30 day computed tomography angiogram into low risk groups (delayed imaging to five years) or higher risk groups (continue with the current protocol). The aim was to test this suggested protocol retrospectively within an EVAR patient cohort.

METHODS

Data on EVARs performed from October 2009 to October 2019 were collected. Information gathered from an existing surveillance programme was used to assess the proposed ESVS protocol. All patients who underwent re-intervention were reviewed to see whether adopting the proposed ESVS protocol would have detected these events.

RESULTS

In total, 309 procedures were included. Altogether, 219 of these patients had no endoleak (70.9%) and 86 had a type II (27.8%) endoleak. Only four developed a type I or III endoleak. No patient in the low risk cohort (no initial endoleak or sac shrinkage > 1 cm) required secondary intervention. Five year follow up data were available for 103 patients. In the type II endoleak group, there were 28 secondary interventions in 22 patients. No patient experienced a ruptured aneurysm within five years post-operatively. Had the proposed ESVS protocol been followed, all patients requiring a secondary intervention or with increasing sac size would have been detected/captured. Further, adherence to the ESVS guidelines would have resulted in 103 patients with a five year follow up history qualifying for reduced surveillance. A further 120 patients who had reached the three and four year follow up timepoints could have qualified for a reduced surveillance, reducing imaging cost further.

CONCLUSION

Adopting the proposed ESVS EVAR surveillance protocol safely identified "low risk" patients who did not go on to require a secondary intervention. These patients could benefit from reduced surveillance scanning.

Type 3 Endoleaks in Complex Endovascular Abdominal Aortic Aneurysm Repair within the Vascular Quality Initiative

OBJECTIVE

Type 3 Endoleaks (T3EL) following complex EVAR (c-EVAR) for abdominal aortic aneurysm have been historically difficult to study due to their relative rarity. Previous studies within standard infrarenal EVAR have found an association between T3EL and decreased survival. This study aims to evaluate the occurrence of T3EL in a national multicenter cohort, identify potential procedural characteristics associated with T3EL development, and determine their impact on clinical outcomes in c-EVAR.

METHODS

A retrospective cohort review was conducted of elective c-EVAR for non-ruptured aneurysms within the Vascular Quality Initiative (VQI) between January 2010 and March 2020. The VQI standards define c-EVAR as suprarenal or pararenal AAA repaired with any thoracoabdominal repairs, fenestrated/branched repairs, parallel stent repairs, custom manufactured devices, and physician modified endografts. End-points assessed were rates of T3EL within c-EVAR, and impact of T3EL on reintervention and survival. Index endoleaks were defined as endoleaks discovered during index hospitalization. Incident endoleaks were defined as new endoleaks, that were not present at index hospitalization, discovered at follow-up.

RESULTS

4,070 c-EVAR cases were identified between January 2010 and March 2020, of which, 2,656 (65.2%) had appropriate follow-up data. Half the cohort had a modified or custom graft (n=2,055/4,070, 50.5%). Branches were employed in 3,687 patients (90.5%), while fenestrations and chimney techniques were documented in 13% (n=533) and 15.1% (n=613) respectively . The rate of index T3EL was 4.1% (n=167), and the rate of incident T3EL at follow-up was 0.04% (n=1). Devices categorized as either custom or physician modified were utilized more frequently in patients with index T3EL (78.4%, n=131/167) compared to patients without index T3EL (49.2%, n=1,924/3,903) (p<0.001). Compared to those without T3EL, the presence of index T3EL was not statistically associated with increased aortic reinterventions or increased mortality.

CONCLUSIONS

T3EL in c-EVAR remain relatively uncommon and are identified predominately at index hospitalization. Development of T3EL was associated with higher device modularity and modification, which suggests that as device technologies continue to advance and become more intricate the occurrence of T3EL may persist and continue to require evaluation. In this study, the presence of T3EL did not appear to have a statistically significant relationship with aortic reinterventions or survival, however these findings are not definitive due to low event rate numbers and high potential for Type 2 errors. Amid the theoretical risk of device fatigue and degeneration, continued evaluations of large cohorts at extended follow-up intervals and diligent reporting remain paramount.

Relining of infrarenal stent-graft with preloaded modified Gore Excluder for occult endoleak with sac expansion

Endoleaks remain one of the most common indications for reintervention after endovascular aortic repair. Occasionally, aneurysm sac expansion will occur in the absence of a visible endoleak or due to endotension. We describe a case of continued sac expansion without an identifiable endoleak after endovascular aortic repair. Technical challenges during the case included a short distance from the renal arteries to the flow divider and a significant metal artifact. These challenges were addressed by shortening the gate of a Gore Excluder (W.L. Gore & Associates, Flagstaff, Ariz) to the desired length. The contralateral gate was preloaded to allow for use of the snare-ride technique for gate cannulation and overcome the metal artifact that was hindering visualization.

Fenestrated endovascular repair with large device diameters (34- to 36-mm) is associated with type 1 and 3 endoleak and reintervention

OBJECTIVES

 Patients with abdominal aortic aneurysms undergoing EVAR with larger device diameters (34- to 36-mm) have worse outcomes due to proximal fixation failure and need for reintervention. We examine outcomes relating to standard fenestrated repair (FEVAR) with larger device diameters, and investigate whether a similar relationship exists.

MATERIAL AND METHODS

 Retrospective review of a prospectively maintained, single institution database of patients treated with the Cook ZFEN device between 2012-2017. Outcomes were stratified by device diameter into normal-diameter (ND,≤ 32 mm) and large-diameter (LD,34-36 mm). Primary endpoints were need for reintervention and composite type I/III endoleak.

RESULTS

 100 consecutive patients treated were identified for inclusion. Overall mean age was 73.6 years and mean aortic diameter was 59.1 mm. Mean follow-up was 22 months. A total of 26 (26%) patients were treated with LD devices. Number of target vessels per patient was 2.8 in both groups. Infrarenal neck length and diameter were significantly different in the LD and ND patients, respectively (2.6 mm vs 4.7 mm (P<.01) and 30.1 mm vs 23.4 mm (P<.01)). Percent graft oversizing was lower in the LD cohort (19% vs 24%; P=.006). No difference was seen in overall mortality at 30-days (0% vs 2%; P=.4) or at latest follow up (6% vs 14%; P=.6). Reinterventions were not significantly different at 30 days, but were significantly higher over the follow-up period in the LD cohort (46.2 vs. 17.6%; P=.002). LD diameter was associated with reintervention on univariate (HR 1.19, 95% CI 1.04-1.37), but not multivariate analysis. The composite endpoint of type I/III endoleak was higher in the LD cohort (15.4% vs. 2.7%; P=.004).

CONCLUSION

 FEVAR requiring 34- or 36-mm device diameters is associated with an increased risk of composite type I/III endoleak and reintervention. Patients undergoing fenestrated repair requiring LD devices should be closely monitored, with consideration for proximal or open repair.

Computational analysis of endovascular aortic repair proximal seal zone preservation with endoanchors: A case study in cylindrical neck anatomy

Background

Endovascular aortic repair is the common approach for abdominal aortic aneurysms, but endoleaks remain a significant problem with long-term success. Endoanchors have been found to reduce the incidence of type 1A endoleaks and can treat intraoperative type 1a endoleaks. However, little is known about the optimal number and position of endoanchors to achieve the best outcome.

Methods

Using image segmentation and a computational model derived from a reconstructed native patient abdominal aortic aneurysm geometry, the stability of the proximal seal zone was examined through finite element analysis in Abaqus (Dassault Systèmes, Providence, RI). The biomechanical parameter of contact area was compared for varying numbers (0, 2, 4, 8) and positions (proximal, medial, distal) of endoanchors under different adhesion strengths and physiologic pressure conditions.

Results

In every simulation, an increase in adhesion strength is associated with maintenance of proximal seal. For biologically plausible adhesion strengths, under conditions of normal blood pressure (120 mm Hg), the addition of any number of endoanchors increases the stability of the endograft-wall interface at the proximal seal zone by approximately 10% compared with no endoanchors. At hypertensive pressures (200 mm Hg), endoanchors increase the stability of the interface by 20% to 60% compared with no endoanchors. The positioning of endoanchors within the proximal seal zone has a greater effect at hypertensive pressures, with proximal positioning increasing stability by 15% compared with medial and distal positioning and 30% compared with no endoanchors.

Conclusions

Endoanchors improve fixation within the proximal seal zone particularly under conditions of high peak systolic pressure. Seal zone stabilization provides a mechanism through which endoanchor addition may translate into lower rates of type 1a endoleaks for patients.

Endovascular aortic repairs are commonly used to treat abdominal aortic aneurysms. Type 1a endoleaks threaten the long-term durability of repairs. Endoanchors have been found to reduce the incidence of this complication. Herein, we examine parameters surrounding optimal endoanchor number and positioning to reduce endovascular aortic repair failure. The computational modeling allowed for testing of endoanchors in varied adhesion strength between the endograft and the aorta, as well as hemodynamic conditions to mimic normotension vs hypertension. The results of the finite element analysis suggest that the addition of any number of endoanchors in the proximal seal zone is beneficial, especially with hypertensive loading.

The impact of type 1a endoleak on the long-term outcome after EVAR

OBJECTIVE

Endoleaks remains a major determinant of outcome after endovascular aortic repair (EVAR) for infrarenal abdominal aortic aneurysms. The objective of this study is to evaluate the long-term impact of proximal type 1 endoleak encountered at the case end of the EVAR procedure or during follow-up.

METHODS

All patients treated with EVAR between February 2001 and August 2017 in our institution were included. Data were collected retrospectively. A descriptive analysis of subgroups with type 1a endoleak at case end or with type 1a endoleak first encountered during follow-up was performed.

RESULTS

In total, 468 patients were included for analysis. At the case end of the EVAR procedure, in 5.3% (25/468) of patients, a type 1a endoleak was seen. In 72% of cases (18/25) the type 1a endoleak spontaneously disappeared on the first follow-up computed tomography angiography and never recurred. At the end of the follow-up period, no patient in this subgroup died with a type 1a endoleak on follow-up. In 3.4% (16/468) of all cases, a type 1a endoleak was encountered for the first time during follow-up. In 87.5% (14/16) of these cases, reintervention was performed. Two patients died with a persisting type 1a endoleak during follow-up.

CONCLUSIONS

Clinicians should differentiate between the type 1a endoleak at the case end and the type 1a endoleak first occurring during follow-up. For type 1a endoleak at the case end, expectant management can be adopted. Delayed type 1a endoleak seen during follow-up rarely seals spontaneously and needs reintervention in the majority of cases.

Management of Postoperative Complications Following Endovascular Aortic Aneurysm Repair

Endovascular aneurysm repair (EVAR) is a minimally invasive therapeutic approach to manage abdominal aortic pathologies (eg, aneurysm and dissection). EVAR was first introduced in 1991. In 1994, endovascular technique was also applied for thoracic aorta, thoracic endovascular aortic repair (TEVAR). In recent decades, EVAR has become an acceptable first-line treatment with 50% utilization rate across most practices, especially in high-risk patients. The safety profile of EVAR is comparable to the open approach, with superiority in terms of perioperative mortality and morbidity. This article summarizes the most common complications following EVAR/TEVAR and the most current treatment modalities across practices.

An International, Multicenter Retrospective Observational Study to Assess Technical Success and Clinical Outcomes of Patients Treated with an Endovascular Aneurysm Sealing Device for Type III Endoleak

INTRODUCTION

Type III endoleaks post-endovascular aortic aneurysm repair (EVAR) warrant treatment because they increase pressure within the aneurysm sac leading to increased rupture risk. The treatment may be difficult with regular endovascular devices. Endovascular aneurysm sealing (EVAS) might provide a treatment option for type III endoleaks, especially if located near the flow divider. This study aims to analyze clinical outcomes of EVAS for type III endoleaks after EVAR.

METHODS

This is an international, retrospective, observational cohort study including data from 8 European institutions.

RESULTS

A total of 20 patients were identified of which 80% had a type IIIb endoleak and the remainder (20%) a type IIIa endoleak. The median time between EVAR and EVAS was 49.5 months (28.5-89). Mean AAA diameter prior to EVAS revision was 76.6±19.9 mm. Technical success was achieved in 95%, 1 patient had technical failure due to a postoperative myocardial infarction resulting in death. Mean follow-up was 22.8±15.2 months. During follow-up 1 patient had a type Ia endoleak, and 1 patient had a new type IIIa endoleak at an untreated location. There were 5 patients with aneurysm growth. Five patients underwent AAA-related reinterventions indications being: growth with type II endoleak (n=3), type Ia endoleak (n=1), and iliac aneurysm (n=1). At 1-year follow-up, the freedom from clinical failure was 77.5%, freedom from all-cause mortality 94.7%, freedom from aneurysm-related mortality 95%, and freedom from aneurysm-related reinterventions 93.8%.

CONCLUSION

The EVAS relining can be safely performed to treat type III endoleaks with an acceptable technical success rate, a low 30-day mortality rate and no secondary ruptures at short-term follow-up. The relatively low clinical success rates, related to reinterventions and AAA enlargement, highlight the need for prolonged follow-up.

Long-term outcomes and interventions of postoperative type 1a endoleak following elective endovascular aortic aneurysm repair

OBJECTIVE

This study evaluated the incidence and long-term outcomes of postoperative type 1a endoleak (PT1a) following endovascular aortic aneurysm repair (EVAR).

METHODS

A retrospective review of consecutive aorto-iliac EVARs performed at a single institution from June 2006 to June 2012 was conducted. Patients with PT1a were identified by postoperative imaging and compared with those who did not develop a PT1a. Late outcomes were also studied of a subset of patients with PT1a who had persistent intraoperative type 1a endoleak (iT1a) on completion angiogram during EVAR that had resolved on initial follow-up imaging.

RESULTS

Three hundred eighty-nine patients underwent EVAR with median follow-up of 87 months (interquartile range, 64-111 months). The incidence of PT1a was 8.2% (n = 32) with a median follow-up of 74 months (interquartile range, 52-138 months). Compared with the total cohort, those who developed PT1a were statistically more likely to be female (32% vs 17%; P = .03) and have a higher all-cause mortality (71% vs 40%; P < .01) and aneurysm-related mortality (15.6% vs 1.7%; P < .01). Median time to presentation was 52 months. Of the 32 patients with PT1a, five (15.6%) presented with aortic rupture, of which three underwent extension cuff placement, one had open graft explant, and one declined intervention. Six patients in total (18.7%) declined intervention; five of these died of nonaneurysmal causes and one remains alive. Of the 26 patients with PT1a who had intervention, 21 (80.7%) showed resolution of PT1a, and five (19.2%) had recurrence. For patients with recurrent PT1a, two had resulting aneurysm-related mortality, two endoleaks resolved after relining with an endograft, and one patient declined intervention but remains alive. Patients with PT1a who had intervention with resolution showed no significant difference in median survival estimates (140.0 months) compared with the remaining EVAR cohort (120.0 months; P = .80). Within the PT1a cohort, 6 (18.7%) had also experienced iT1a with a mean time to presentation of the late PT1a of 45 months. iT1a was associated with a significantly increased likelihood of developing a PT1a (P < .01) and decreased median survival (P < .01), but there was no known aneurysm-related mortality.

CONCLUSIONS

Development of PT1a following elective EVAR is associated with increased all-cause and aneurysm-related mortality and presents an average of 52 months postoperatively. This underscores the importance of long-term surveillance. Patients with PT1a who had a successful intervention showed no significant difference in median survival. Those with iT1a had a higher risk for PT1a compared with the EVAR cohort overall and had decreased median survival, without increased aneurysm-related mortality.

Systematic review of embolization of type I endoleaks using liquid embolic agents

OBJECTIVE

The long-term success of endovascular aneurysm repair (EVAR) is limited by complications, most importantly endoleaks. In case of (persistent) type I endoleak (T1EL), secondary intervention is indicated to prevent secondary aneurysm rupture. Different treatment options are suggested for T1ELs, such as endo anchors, (fenestrated) cuffs, embolization, or open conversion. Currently, the treatment of T1EL with liquid embolic agents is available; however, results are not yet addressed. This review presents the safety and efficacy of embolization with liquid embolic agents for treatment of T1ELs after EVAR.

METHODS

A systematic literature search was performed for all studies reporting the use of liquid embolic agents as monotherapy for treatment of T1ELs after EVAR. Patient numbers, technical success (successful delivery of liquid embolics in the T1EL) and clinical success (absence of aneurysm related death, endoleak recurrence or additional interventions during follow-up) were examined.

RESULTS

Of 1604 articles, 10 studies met the selection criteria, including 194 patients treated with liquid embolics; 73.2% of the patients were male with a median age of 71 years. The overall technical success was 97.9%. Clinical success was 87.6%. Because the median follow-up was only 13.0 months (range, 1-89 months), data on long-term success are almost absent. Four cases (2.1%) of secondary aneurysm rupture after embolization owing to endoleak recurrence were reported. All ruptures occurred in aneurysms exceeding initial treatment diameter of 70 mm.

CONCLUSIONS

Initial technical success after liquid embolization for T1EL is high, although long-term clinical success rates are lacking. Within this review, the risk of secondary rupture is comparable with untreated T1EL at 2% with a median follow-up of 13 months, regardless of the initial success of embolization. In general, no decrease in secondary aneurysm rupture after embolization of T1EL after EVAR is demonstrated, although the results of late embolization are debated.

Pressure gradient measurement to verify hemodynamic results of the chimney endovascular aortic repair (chEVAR) technique

PURPOSE

The use of the pressure gradient measurements to assess the renal artery flow hemodynamics after chimney endovascular aortic repair (chEVAR).

METHODS

The study was a prospective analysis of 37 chEVAR procedures performend in 24 patients with perirenal aortic aneurysm. In all patients the measurement of: distal renal artery pressure (Pd), aortic pressure (Pa), Pd/Pa ratio (Pd/Pa) and mean gradient (MG) between the aorta and the distal renal artery were performed. Measurements were taken with 0.014 inch pressure wire catheter before and after the chEVAR procedure. MG greater than 9 mmHg and Pd/Pa ratio below 0.90 were considered as the measures of a significant decrease in distal pressure that limited flow in renal arteries. The 6 month follow-up computed tomographic angiography (CTA) was performed in all patients to diagnose potential endoleak presence and to verify the patency of the chimney stent-grafts.

RESULTS

All procedures were successful, and no periprocedural complications were observed in any of the patients. The mean gradient values before and after the chimney implantation did not change significantly (6,2±2,0 mmHg and 6,8±2,2 mmHg, respectively). Similarly, no significant change in Pd/Pa values was noted with the value of 0.9 observed both before and after the procedure. All chimney stents were patent on the control CTA. Type Ia endoleak was found in 4 (10.8%) patients.

CONCLUSIONS

The application of the described technique seems to be a safe method which allows a direct measurement of renal artery flow hemodynamics before and after chimney implantation during the chEVAR technique. The use of covered balloon expandable stents, ensures the proper blood flow in the renal arteries during the chEVAR technique.

Endotension: What do we know and not know about this enigmatic complication of endovascular aneurysm repair

As the use of endovascular approaches to treat aneurysm repair continues to increase, more and more patients have been identified with endoleaks. Five types of endoleaks have been defined. Endotension, or type V endoleak, remains controversial owing to its variable definition across studies and the range of proposed treatments. Thus, we performed a review of the reported studies to summarize the diagnosis and treatment of this rare complication after endovascular aneurysm repair to determine what we do and do not know about this rare form of endoleak. The presence of an endoleak places patients at an increased risk of aneurysm sac enlargement and potential rupture. Although additional research is essential and yet difficult to perform, we sought to provide a guide for the management of this perplexing endoleak known as endotension.

Midterm single-center results after endovascular aneurysm sealing reveal a high rate of stent graft migration, secondary aneurysm ruptures, and device-related reinterventions

OBJECTIVE

To report procedural results and mid-term follow-up outcomes of patients treated with endovascular aneurysm sealing (EVAS) for abdominal aortic disease.

METHODS

In this retrospective observational study, all patients treated with EVAS between March 2013 and January 2018 for abdominal aortic aneurysm (AAA) or abdominal penetrating aortic ulcer were included. The datasets included demographics, aneurysm morphology, and procedural and clinical surveillance outcomes. Furthermore, patients treated within the original instructions for use (IFU-group) were compared with patients treated outside the IFU (non-IFU-group) with regard to survival, reintervention-free survival, freedom from type I endoleak, and freedom from stent graft migration.

RESULTS

Seventy patients were included (67 male; median age, 72.5 years). Sixty-five patients were treated for AAA and 5 patients for abdominal penetrating aortic ulcer. Sixty-nine cases were treated electively (98.6%). Technical success was achieved in 68 cases (97.1%). The median clinical follow-up was 50.5 months (interquartile range, 29.3-62.7 months) with a median computed tomography angiographic follow-up of 38.5 months (interquartile range, 17.1-60.2 months). There were five deaths during the study period (7.1%), four of which were aneurysm related (5.7%). Five secondary AAA ruptures were detected (7.1%). Overall, 25 of 70 patients (35.7%) underwent 35 reinterventions, mostly owing to thrombotic complications (18.6%), stent graft migration (17.1%), and type I endoleak (12.9%). Fifteen patients were treated outside of the IFU (non-IFU-group) (21.4%). The estimated reintervention-free survival for the entire cohort at 30 days and 1, 3, and 5 years was 94.3%, 88.5%, 72%, and 56.9%, respectively. Freedom from stent graft migration at 1, 3, and 5 years was 98.6%, 82.0%, and 47.3%, respectively. The estimated freedom from type I endoleak at 30 days and 1, 3, and 5 years in the IFU-group was 100%, 100%, 94.9% and, 91.1% and significantly different when compared with the non-IFU-group with 79.5%, 72.2%, 72.2%, and 72.2% (P = .012).

CONCLUSIONS

Although the technical and initial results were satisfying, the mid-term results were disappointing. The enforcement of a close follow-up protocol for all patients treated with EVAS, especially vigilant for stent graft migration to prevent secondary type I endoleak and rupture, is strongly recommended.

Hybrid Approach with Angiography and Limited Open Exposure to Treat Type Ia Endoleaks after Endovascular Aortic Aneurysm Repair

BACKGROUND

Type Ia endoleaks after endovascular aortic repair (EVAR) almost always mandate secondary percutaneous reinterventions. Several patients, however, will require conversion to open surgical repair with complete graft explant, which is associated with significant morbidity and mortality. We herein present 3 cases of hybrid surgical repair for type Ia endoleaks, using a limited open exposure for proximal stent graft edge revision to achieve graft preservation and effective aneurysm sac exclusion.

METHODS

Angiography was used to confirm type Ia endoleak in 3 patients (2 males) who had previous EVAR between October 2017 and October 2019. Time to the endoleak after the index EVAR was immediate in 1 patient during repair of a ruptured aneurysm, 2 months in 1 patient and 2 years in 1 patient. The aorta was exposed through a limited transabdominal (n = 1) or retroperitoneal (n = 2) approach and circumferential aortic control was achieved below the renal arteries. A row of interrupted horizontal mattress sutures of 3-0 polypropylene reinforced with Teflon pledgets was placed along the aortic neck circumference. Multi-planar angiography was then repeated to verify the absence of sac filling and successful type Ia endoleak exclusion. Follow-up abdominal duplex was obtained for all 3 patients after discharge to monitor the stent graft and confirm endoleak resolution. Furthermore, there were no instances of acute renal failure.

RESULTS

In the period of review, 77 patients underwent EVAR. In the 3 patients described, we were able to achieve complete aneurysm sac exclusion and stent graft preservation in all cases. Follow-up imaging was available on 2 patients at 4-6 weeks after surgery demonstrating sustained exclusion of the endoleak. Two patients died during follow-up: one from a myocardial infarction 7 weeks after surgery and one from metastatic lung cancer at 8 months after surgery. Follow up duplex imaging at one year on the single survivor demonstrated sac shrinkage and absence of endoleak.

CONCLUSIONS

Type Ia endoleaks represent a significant source of morbidity and mortality after EVAR and typically require repair to avoid aneurysm rupture. Our use of limited proximal revision without explant provides an alternative approach to resolve the endoleaks while reducing the magnitude of physiological stress when compared to an open explant. It represents a feasible option for high-risk patients.

A Systematic Review and Pooled Meta-Analysis on the Incidence and Temporal Occurrence of Type II Endoleak Following an Abdominal Aortic Aneurysm Repair

BACKGROUND

The aim in this study was to systematically review the literature to identify the time of occurrence of a newly diagnosed Type II endoleak (T2E) following an endovascular aneurysm repair (EVAR) for an infrarenal abdominal aortic aneurysm (AAA) and its potential impact on aneurysmal sac diameter changes.

METHODS

A comprehensive systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Eligible studies were identified through a search of PubMed, Scopus and Cochrane until January 2020. A meta-analysis was conducted with the use of a random effects model. The I-square statistic was used to assess for heterogeneity.

RESULTS

Thirty-three observational studies were deemed eligible and provided data for 2643 T2E detected following EVAR. A total of 1432 (54.2%) T2E were diagnosed before 30 days follow-up, while 1035 (39.1%) T2E were diagnosed beyond 30 days following EVAR. A total of 222 (8.4%) T2E were diagnosed after 12 months of follow-up. A pooled meta-analysis of 6 studies, showed that early diagnosed T2E had a statistically significant higher odds of resolving as compared to those detected late (OR: 2.41; 95% CI: 1.14-5.09; P = 0.021; I² = 68.9%). Sac expansion was documented in 313 (29%) T2E. The ruptured endoleaks were 14 (1.1%).

CONCLUSIONS

The occurrence of a T2E is a dynamic process detected throughout the lifetime of a patient with 8% detected beyond 12 months following EVAR. Long-term follow up is required with future prospective studies with consist reporting on changes in sac diameter, the thrombus characteristics. Long-term outcomes are needed to optimize management of patients with a newly diagnosed T2E.

Occurrence and outcomes of type 3 endoleaks in endovascular aortic repair within the Vascular Quality Initiative database

Objectives

Type 3 endoleaks (T3ELs) represent a lack of aneurysm protection from systemic pressure. Previous studies have found a ~2% incidence of T3EL after standard infrarenal endovascular aneurysm repair (EVAR); however, no prior studies with new-generation devices have been able to determine an association between T3EL and clinical outcomes. Here we examine T3EL within the Society for Vascular Surgery Vascular Quality Initiative (VQI) to define rates of occurrence, rates and modes of reintervention, and clinical consequences of these endoleaks.

Design and setting

Participants receiving infrarenal EVAR in the VQI from January 2003 to September 2018 were analyzed in a retrospective cohort study.

Participants

Of 42 246 entries in the EVAR procedural registry, 41 604 had complete procedural information and were included in analysis. Of these, 36 082 had long-term follow-up, and 26 422 had follow-up (9-21 months per VQI reporting standards) with complete endoleak data recorded.

Interventions

All patients included in this study underwent an infrarenal EVAR.

Results

Within the VQI database, the rate of T3EL in infrarenal EVAR during index hospitalization was 0.37% (n=157/41 604), of which 85% were due to midgraft separation and 15% were due to fabric disruptions. Out of the 157 index hospitalization T3ELs, 4.5% (n=7) received procedural reintervention during that hospitalization, which accounted for 1% of all index hospitalization reinterventions. During the 21-month follow-up, the rate of incident T3EL was 0.7% (n=205/26 422), which accounted for 5% of all endoleaks seen during follow-up. Reinterventions for incident T3EL at follow-up were done in 30 patients (rate 0.1%), which accounted for 9% of endoleak reinterventions and 3.3% of all reinterventions. The presence of incident T3EL found during follow-up was associated with a significant decrease in 5-year survival (74% vs 80%, respectively; p=0.041) in Kaplan-Meier analysis.

Conclusion

T3ELs rates at placement and follow-up remain low; however, the majority reported in long-term follow-up are incident and these incident endoleaks are associated with decreased survival in EVAR.

Complications and Management of the Thoracic Endovascular Aortic Repair

Endovascular treatment in thoracic aortic diseases has increased in use exponentially since Dake and colleagues first described the use of a home-made transluminal endovascular graft on 13 patients with descending thoracic aortic aneurysm at Stanford University in the early 1990s. Thoracic endovascular aneurysm repair (TEVAR) was initially developed for therapy in patients deemed unfit for open surgery. Innovations in endograft engineering design and popularization of endovascular techniques have transformed TEVAR to the predominant treatment choice in elective thoracic aortic repair. The number of TEVARs performed in the United States increased by 600% from 1998 to 2007, while the total number of thoracic aortic repairs increased by 60%. As larger multicenter trials and meta-analysis studies in the 2000s demonstrate the significant decrease in perioperative morbidity and mortality of TEVAR over open repair, TEVAR became incorporated into standard guidelines. The 2010 American consensus guidelines recommend TEVAR to be “strongly considered” when feasible for patients with degenerative or traumatic aneurysms of the descending thoracic aorta exceeding 5.5 cm, saccular aneurysms, or postoperative pseudoaneurysms. Nowadays, TEVAR is the predominant treatment for degenerative and traumatic descending thoracic aortic aneurysm repair. Although TEVAR has been shown to have decreased early morbidity and mortality compared with open surgical repair, endovascular manipulation of a diseased aorta with endovascular devices continues to have significant risks. Despite continued advancement in endovascular technique and devices since the first prospective trial examined the complications associated with TEVAR, common complications, two decades later, still include stroke, spinal cord ischemia, device failure, unintentional great vessel coverage, access site complications, and renal injury. In this article, we review common TEVAR complications with some corresponding radiographic imaging and their management.

Type 2 Endoleak Management

Type 2 endoleaks are the most common endoleak type following endovascular aneurysm repair. The natural history of these endoleaks can vary, with some demonstrating a self-limited or indolent course, while others can contribute to aneurysm sac enlargement and rupture. A variety of embolization techniques, including transarterial catheterization and direct sac puncture techniques, have been developed for the treatment of type 2 endoleaks. In this article, the authors review the indications, techniques, and outcomes of current treatment strategies for type 2 endoleaks.

Evolving Concepts, Management, and Treatment of Type 1 Endoleaks after Endovascular Aneurysm Repair

Over the past 20 years, there has been tremendous progress in endovascular aneurysm repair techniques and devices. The application of new third- and fourth-generation devices (from 2003 onward) has led to changes in the incidence and management of endoleaks. This comprehensive review aims to outline the most recent concepts with respect to pathophysiology/risk factors and management of Type 1 endoleaks.

Risk Factors for Early and Late Type Ib Endoleak Following Endovascular Abdominal Aortic Aneurysm Repair

OBJECTIVES

A type Ib endoleak (T1bEL) is a postoperative complication that usually requires additional interventions following endovascular aortic aneurysm repair. Previous studies have focused on iliac artery tortuosity or common iliac artery (CIA) diameter. However, we investigated the various risk factors for early and late T1bELs more comprehensively.

METHODS

This retrospective case-control study of a prospectively maintained database compared anatomical, demographic and technical factors between patients with early or late T1bELs and a control group. Early T1bEL was defined as a T1bEL occurring within 6 months of endovascular aneurysm repair (EVAR), while late T1bEL was defined as a T1bEL, initially identified more than 6 months after EVAR. Anatomical values including neck diameter, length, and angle; maximum sac diameter and length; CIA length, diameter, and tortuosity; and distal sealing length were measured and included in the analysis. We performed uni- and multivariable analyses using logistic regression and Cox proportional hazard models.

RESULTS

This study included 635 iliac limbs of 383 patients. Overall, T1bELs occurred in 22 iliac limbs during the follow-up period (22/635, 3.5%). Among them, the early and late T1bEL groups each included 11 limbs. The median follow-up duration of the 383 patients was 23 (8-58) months, and in the early T1bEL and early control groups, the durations were 15 (9-35) and 29 (15-60) months, respectively (P = 0.01). The median overall follow-up durations in the late T1bEL and late control groups were 87 (76-102) and 62 (48-80) months, respectively (P = 0.01). The median follow-up duration until the occurrence of late T1bEL was 44 (32-82) months, which was shorter than that of the late control group (P = 0.03). No significant differences in sex, age, or brand of stent-graft were observed between the T1bEL and control groups. In the multivariable analysis, patients in the early T1bEL group had significantly more tortuous and short CIAs, and short distal sealing lengths (P = 0.02, P = 0.04, P = 0.03, respectively), and the late T1bEL group had significantly larger maximum aortic aneurysm sac diameters, short CIAs and short distal sealing lengths (P < 0.001, P = 0.02, P = 0.002, respectively). The suspected mechanisms of the T1bELs were CIA dilatation with or without sac expansion and aggravation of sac angulation. Except for one patient with aortic dissection, T1bELs were treated with iliac limb extensions.

CONCLUSIONS

The various mechanisms of T1bELs differed depending on the time of onset from the procedure. An extensive sealing length may be protective against T1bEL, especially when the size of the aortic aneurysm sac is large or when the CIA has risky features, including large diameter or short length. Careful preoperative consideration of aortic aneurysm size and CIA length and tortuosity is essential, and patients with risky features should undergo strict postoperative surveillance.

Total realignment of multibranch stent graft using redo branch-in-branch endovascular repair for occult endoleak with rapid aneurysm sac expansion

Occult endoleaks can pose a diagnostic and treatment challenge. These endoleaks are not effectively identified by multiphase computed tomography angiography, magnetic resonance angiography, or contrast-enhanced ultrasound. Possible causes are small fabric tears and slow-flow, dynamic, or positional endoleaks. We describe a patient with rapid aneurysm sac expansion and disseminated intravascular coagulopathy 46 months after four-vessel branched physician-modified endograft repair of a ruptured extent III thoracoabdominal aneurysm. Imaging failed to demonstrate an endoleak but identified fresh blood products within the sac. The patient underwent total realignment using branch-in-branch repair with a physician-modified endograft. Repeated imaging 25 days postoperatively revealed decrease in aneurysm diameter by 10 mm.