Fenestrated Stent Grafting for Short-necked and Juxtarenal Abdominal Aortic Aneurysm: An 8-Year Single-centre Experience

Comparing Mobile C-Arm with a Hybrid Operating Room for Imaging in Fenestrated Stent-Graft Endovascular Abdominal Aortic Aneurysm Repair

BACKGROUND

To evaluate the advantages of a hybrid operating room (OR) (group 2) compared with a fluoroscopic mobile C-arm (group 1) during fenestrated stent-graft endovascular aneurysm repair (f-EVAR).

METHODS

This single-center study retrospectively analyzed prospectively collected data of consecutive patients treated with f-EVAR for short-necked, juxtarenal, and suprarenal aortic aneurysms between January 2006 and July 2016. Primary end points were technical success and perioperative complications. Secondary end points included 30-day and 1-year mortality as well as target vessel patency.

RESULTS

About 96 patients were treated (85 men; 74.1 ± 6.3 years); 46 patients (48%) belonging to group 1 and 50 (52%) patients belonging to group 2. Technical success was achieved in 92.7% of the procedures (group 1 91.3% vs. group 2 94%, P = 0.72). Significantly more complex interventions were performed in group 2 (n = 38 of 50) compared with group 1 (n = 14 of 46; P < 0.001), in which primarily renal f-EVAR interventions were performed. In group 2, significantly less contrast was used (median 150 mL vs. 100 mL; P < 0.001). The 30-day mortality in group 1 was 9% and 2% in group 2 (P = 0.14), and 1-year survival was also not significantly different between both groups. Target visceral vessel primary patency was significantly higher in group 1 (87.6% vs. 85.5% [P = 0.006] and 83.8% vs. 78.3% [P = 0.03]) at 6 and 12 months, respectively). There was no significant difference in renal artery primary patency at 6 and 12 months.

CONCLUSIONS

Immediate and 1-year outcomes after f-EVAR for abdominal aortic aneurysm were comparable using a hybrid OR compared with a mobile C-arm, despite the use of significantly more complex stent grafts in the patients treated in the hybrid OR. The use of a hybrid OR may assist in achieving satisfying results in complex f-EVAR.

Comparison of open and endovascular repair of juxtarenal abdominal aortic aneurysms

BACKGROUND

This study compares the perioperative outcome in elective repair of the juxtarenal abdominal aortic aneurysm (AAA), depending upon whether patients received an open (OAR) or endovascular procedure (EVAR).

METHODS

The database stems from the 2013-2017 AAA registry of the German Institute for Vascular Health Research (DIGG) of the German Society for Vascular Surgery and Vascular Medicine (DGG), with a total of 1603 juxtarenal AAAs. 786 patients (49.0%) were treated with an endovascular (EVAR) procedure, and 817 (51.0%) with an open (OAR) procedure.

RESULTS

Patients receiving EVAR had a median age of 73 years and those receiving OAR a median age of 71 years (p < 0.001). The proportion of patients over 80 years of age was 17.0% for EVAR and 9.9% for OAR (p < 0.001). The proportion of women receiving EVAR (16.9%) was slightly lower than that receiving OAR (18.6%). Aneurysm diameter differed significantly (EVAR mean 57.80 mm, OAR 59.07 mm; p = 0.038). Preoperatively impaired renal function stages 3 to 5 were not significantly different (EVAR 12.5%, OAR 14.4%, p = 0.158). Postoperative complications were significantly less with EVAR (31%) than with OAR at 45.7% (p = 0.001). In regard to MACE (major adverse cardiac events = perioperative death, stroke, or myocardial infarction), there were no significant differences between EVAR (8.8%) and OAR (10.3%) (p = 0.191). Hospital mortality was only in trend lower with EVAR than with OAR (5.7% vs. 7.7%, respectively; p = 0.068). This held true for the hospital mortality in the group above 80 years of age as well. Inpatient stay was 9 (13.3) days for EVAR and 14 (18.8) days for OAR (p < 0.001). The hospital mortality for women receiving EVAR was 10.5%, and significantly higher (p = 0.008) than that for men (4.7%). The same held true for OAR (hospital mortality for women was 11.8%, for men 6.8%; p = 0.030).

CONCLUSION

In terms of perioperative outcome, the endovascular procedure for treating juxtarenal AAA is more favorable than that documented for OAR. Further investigation is necessary to determine whether EVAR is comparable with OAR in the long term when treating juxtarenal AAA.

Customized stent-grafts for endovascular aneurysm repair with challenging necks: A numerical proof of concept

Endovascular aortic repair (EVAR) is a challenging intervention whose long-term success strongly depends on the appropriate stent-graft (SG) selection and sizing. Most off-the-shelf SGs are straight and cylindrical. Especially in challenging vessel morphologies, the morphology of off-the-shelf SGs is not able to meet the patient-specific demands. Advanced manufacturing technologies facilitate the development of highly customized SGs. Customized SGs that have the same morphology as the luminal vessel surface could considerably improve the quality of the EVAR outcome with reduced likelihoods of EVAR related complications such as endoleaks type I and SG migration. In this contribution, we use an in silico EVAR methodology that approximates the deployed state of the elastically deformable SG in a hyperelastic, anisotropic vessel. The in silico EVAR results of off-the-shelf SGs and customized SGs are compared qualitatively and quantitatively in terms of mechanical and geometrical parameters such as stent stresses, contact tractions, SG fixation forces and the SG-vessel attachment. In a numerical proof of concept, eight different vessel morphologies, such as a conical vessel, a barrel shaped vessel and a curved vessel, are used to demonstrate the added value of customized SGs compared to off-the-shelf SGs. The numerical investigation has shown large benefits of the highly customized SGs compared to off-the-shelf SGs with respect to a better SG-vessel attachment and a considerable increase in SG fixation forces of up to 50% which indicate decreased likelihoods of EVAR related complications. Hence, this numerical proof of concept motivates further research and development of highly customized SGs for the use in challenging vessel morphologies.

Parallel Covered Stents Technique in the Treatment of Abdominal Aortic Diseases

PURPOSE

To investigate the safety and efficacy of the parallel covered stents technique in the treatment of anatomically challenging aortic aneurysms, pseudoaneurysms, and dissections.

MATERIALS AND METHODS

Data were retrospectively collected from 16 patients with abdominal aortic diseases who were treated with parallel covered stents (Gore Excluder, n = 14; Medtronic Endurant, n = 2) between January 2016 and July 2018. Patients were treated with this technique if they were unsuitable for either open repair or standard endovascular aortic repair with bifurcated stents. Such unfavorable anatomy included narrow aortic necks (≤18 mm), small vascular access (occluded or ≤6.0 mm), or compressed aortic lumens (≤18 mm). All patients were male, with a mean age of 64.7 ± 13.3 years. For true aneurysms (n = 4) and pseudoaneurysms (n = 4), the mean diameter and length of the proximal necks were 17.5 ± 2.6 mm (range, 14-21 mm) and 51.0 ± 12.5 mm (range, 39-75 mm), respectively. The minimal diameter of true lumen in cases with aortic dissection and penetrating ulcers (n = 8) was 14.8 ± 3.1 mm. Small or occluded femoral access was found in 3 patients.

RESULTS

Technical success was 100%. Minor type I endoleaks, which were seen on completion angiography in 5 patients, had all resolved within 3 months. There were no perioperative deaths. Postoperative complications included supraventricular tachycardia in 1 patient and pneumonia combined with heart failure in 1 patient. Patency of all stents was observed at a mean follow-up of 21.8 ± 10.1 months.

CONCLUSIONS

The parallel covered stents technique appears to offer a feasible solution for abdominal aortic diseases with unfavorable anatomy. Long-term follow-up is needed to further evaluate the safety and efficacy of this technique.

The role of fEVAR, chEVAR and open repair in treatment of juxtarenal aneurysms: a systematic review

INTRODUCTION

Open repair (OR), fenestrated endovascular aneurysm repair (fEVAR) and endovascular exclusion using parallel graft (chEVAR) are complementary procedures used for treatment of juxtarenal abdominal aortic aneurysm (jrAAA). The aim of our study was to assess available literature and analyze dispersion of OR, fEVAR and chEVAR procedures among reported papers related to treatment of jrAAA.

EVIDENCE ACQUISITION

The PubMed database was systematically searched using predefined strategy and key words related to treatment of jrAAA on September 28th, 2019. Studies were assessed for eligibility using the inclusion and exclusion criteria with at least five patients treated with at least one of the procedures while systematic reviews, meta-analysis, reviews, comments, editorials and letters were excluded as well as studies without clear classification of the location of the aneurysm, studies not specifying the number of patients treated with each of the techniques or not discriminated between aortic pathologies (juxtarenal, paravisceral and thoracoabdominal), hybrid procedures, endoanchors or with branched stent-graft.

EVIDENCE SYNTHESIS

Overall, 1533 papers were identified while papers that met inclusion criteria were either representing experience of single institution (87 papers) or from multicenter studies (6 papers), national or international registries (18 papers). In the period between January 1977 and December 2017, treatment of 5664 patients with jrAAA was reported in 87 papers as a single institution report. Out of them 2531 (45%) were treated with OR, 2592 (46%) with fEVAR and 541 (9%) with chEVAR. Out of 29 institutions reporting OR, there were 11 (37.9%) with more than 100 treated patients while 21 (41.1%) out of 51 institutions that reported more than 50 jrAAA treated with fEVAR. Only four institutions reported results of all three treatment modalities.

CONCLUSIONS

Based on the results reported in the literature, regardless of its complexity and costs, fEVAR for jrAAA has been accepted in substantial number of hospitals worldwide, while number of reported procedures is reaching OR.

Patient Specific Computer Modelling for Automated Sizing of Fenestrated Stent Grafts

OBJECTIVE

The aim was to validate a computational patient specific model of Zenith® fenestrated device deployment in abdominal aortic aneurysms to predict fenestration positions.

METHODS

This was a retrospective analysis of the accuracy of numerical simulation for fenestrated stent graft sizing. Finite element computational simulation was performed in 51 consecutive patients that underwent successful endovascular repair with Zenith® fenestrated stent grafts in two vascular surgery units with a high volume of aortic procedures. Longitudinal and rotational clock positions of fenestrations were measured on the simulated models. These measurements were compared with those obtained by (i) an independent observer on the post-operative computed tomography (CT) scan and (ii) by the stent graft manufacturer planning team on the pre-operative CT scan. (iii) Pre- and post-operative positions were also compared. Longitudinal distance and clock face discrepancies >3 mm and 15°, respectively, were considered significant. Reproducibility was assessed using Bland-Altman and linear regression analysis.

RESULTS

A total of 195 target arteries were analysed. Both Bland-Altman and linear regression showed good reproducibility between the three measurement techniques performed. The median absolute difference between the simulation and post-operative CT scan was 1.0 ± 1.1 mm for longitudinal distance measurements and 6.9 ± 6.1° for clock positions. The median absolute difference between the planning centre and post-operative CT scan was 0.8 ± 0.8 mm for longitudinal distance measurements and 5.1 ± 5.0° for clock positions. Finally, the median absolute difference between the simulation and the planning centre was 0.96 ± 0.97 mm for longitudinal distance measurements and 4.8 ± 3.6° for clock positions.

CONCLUSION

The numerical model of deployed fenestrated stent grafts is accurate for planning position of fenestrations. It has been validated in 51 patients, for whom fenestration locations were similar to the sizing performed by physicians and the planning centre.

Fenestrated endografting is the preferred option for juxta-renal aortic aneurysm reconstruction

BACKGROUND

The aim of this study was to report early/mid-term-up outcomes of fenestrated endografting (FEVAR) for juxta-renal aneurysms (j-AAAs).

METHODS

Between 2008 and 2019, all consecutive j-AAAs treated by FEVAR were prospectively collected and retrospectively analyzed. Early endpoints were technical success, renal function worsening and 30-day mortality. Follow-up endpoints were survival, freedom from re-interventions (FFRs) and target visceral vessels (TVVs) patency.

RESULTS

Among 240 cases of FB-EVAR, 98(41%) were j-AAAs. Endografts with 1,2,3,4 and 5 fenestrations were planned in 3(3%), 25(26%), 35(36%), 33(34%) and 2(1%) cases, respectively. Overall, 360 TVVs were treated by fenestrations and scallops. Technical success was achieved in 97(99%) cases. The only failure was 1 type III endoleak requiring renal artery relining. No TVVs were lost. Renal function worsening was reported in 22(22%) and 12(12%) cases at 24-hour and 30-day, respectively. One patient required hemodialysis and died within 30-day (1%). This was the only case of 30-day mortality. The mean follow-up was 36±32months. Aneurysm sac shrinkage or stability was observed in 55(56%) and 41(42%) cases, respectively. Two (2%) patients with persistent type II endoleak had sac enlargement and required re-interventions. Freedom from reinterventions at 5-year was 86%. An asymptomatic celiac trunk occlusion (accommodated by a scallop) occurred at 24-month in a case with a severe preoperative stenosis. No late renal arteries occlusions or type I-III endoleaks occurred. TVVs-patency was 96% at 5-year. Renal function worsening was reported in 10(10%) patients during follow-up. Survival at 5-year was 73%, with no j-AAA related mortality. Chronic obstructive pulmonary disease (COPD) (P=0.007; OR:4.8; 95% CI: 1.5-15.3) and postoperative renal function worsening (P=0.028; OR:1,1; 95% CI: 1.1-1.2) were independent predictor for mortality at the multivariate analysis.

CONCLUSIONS

FEVAR for j-AAAs is safe and effective at early and long-term follow-up. According with these results, it could be proposed as the first line treatment in high risk patients if anatomically fit. Long term survival is reduced in the presence of preoperative COPD and postoperative renal function worsening.

Intraoperative adverse events and early outcomes of custom-made fenestrated stent grafts and physician-modified stent grafts for complex aortic aneurysms

OBJECTIVE

Physician-modified fenestrated stent grafts (PMSGs) are a useful option for urgent or semiurgent treatment of complex abdominal aortic aneurysms (CAAAs). The aim of this study was to describe in-hospital outcomes of custom-made fenestrated stent grafts (CMSGs) and PMSGs for the treatment of CAAAs and thoracoabdominal aortic aneurysms (TAAAs).

METHODS

In this single-center, retrospective study, all consecutives patients with CAAAs or TAAAs undergoing endovascular repair using Zenith CMSGs (Cook Medical, Bloomington, Ind) or PMSGs between January 2012 and November 2017 were included. End points were intraoperative adverse events, in-hospital mortality, postoperative complications, reinterventions, target vessel patency, and endoleaks.

RESULTS

Ninety-seven patients were included (CMSGs, n = 69; PMSGs, n = 28). The PMSG group included more patients assigned to American Society of Anesthesiologists class 4 (n = 14 [50%] vs n = 16 [23%]; P = .006) and more TAAAs (n = 17 [61%] vs n = 10 [15%]; P < .0001). Intraoperative adverse events were recorded in eight (11%) patients in the CMSG group vs six (21%) patients in the PMSG group. No intraoperative death or open conversion occurred. In-hospital mortality rates were of 4% (n = 3) in the CMSG group and 14% in the PMSG group (n = 4). Chronic renal failure was an independent preoperative risk factor of postoperative death or complications (odds ratio, 4.88; 95% confidence interval, 1.65-14.43; P = .004). Rates of postoperative complications were 22% (n = 15) and 25% (n = 7) in the CMSG and PMSG groups. Spinal cord ischemia rates were 4% (n = 3) and 7% (n = 2) in the CMSG and PMSG groups. Reintervention rates were 16% (n = 11) in the CMSG group and 32% (n = 9) in the PMSG group. At discharge, target vessel patency rate in CMSGs was 98% (n = 207/210). All target vessels (n = 98) were patent in the PMSG group. Endoleaks at discharge were observed in 24% of the CMSG group (n = 16) vs 8% of the PMSG group (n = 2).

CONCLUSIONS

Our study showed clinically relevant differences of several important in-hospital outcomes in the CMSG and PMSG groups. Larger cohorts and longer follow-up are needed to allow direct comparison. PMSGs may offer acceptable in-hospital results in patients requiring urgent interventions when CMSGs are not available or possible.

Fenestrated Endovascular Aneurysm Repair versus Snorkel Endovascular Aneurysm Repair: Competing yet Complementary Strategies

Juxtarenal/pararenal aortic aneurysms and type IV thoracoabdominal aneurysms pose particular technical challenges for endovascular repair as they involve the visceral segment in addition to insufficient infrarenal neck for the use of standard endovascular aneurysm repair (EVAR) devices. To overcome these challenges, complex EVAR techniques have been developed to extend the proximal landing zone cephalad with maintaining perfusion to vital aortic branches, thereby broadening the applicability of endografting from the infrarenal to the suprarenal aorta. Complex EVAR can be divided into two broad categories: fenestrated endovascular aneurysm repair (FEVAR) and snorkel EVAR. FEVAR is a valid procedure with the standardized procedure, although it remains as a relatively complex procedure with a learning curve. Given time constraints for the custom fenestrated graft, snorkel EVAR may be an alternative for complex repairs in symptomatic or ruptured patients for whom custom-made endografts may not be immediately available. This article discusses these two most commonly used complex EVAR strategies.

Quantitative Stent Graft Motion in ECG Gated CT by Image Registration and Segmentation: In Vitro Validation and Preliminary Clinical Results

OBJECTIVES

The dynamic endovascular environment of stent grafts may influence long term outcome after endovascular aneurysm repair (EVAR). The sealing and fixation of a stent graft to the aortic wall is challenged at every heartbeat, yet knowledge of the cardiac induced dynamics of stent grafts is sparse. Understanding the stent-artery interaction is crucial for device development and may aid the prediction of failure in the individual patient. The aim of this work was to establish quantitative stent graft motion in multiphasic electrocardiogram (ECG) gated computed tomography (CT) by image registration and segmentation techniques.

METHODS

Experimental validation was performed by evaluating a series of ECG gated CT scans of a stent graft moving at different amplitudes of displacement at different virtual heart rates using a motion generating device with synchronised ECG triggering. The methodology was further tested on clinical data of patients treated with EVAR devices with different stent graft designs. Displacement during the cardiac cycle was analysed for points on the fixating stent rings, the branches or fenestrations, and the spine.

RESULTS

Errors for the amplitude of displacement measured in vitro at individual points on the wire frame were at most 0.3 mm. In situ cardiac induced displacement of the devices was found to differ per location and also depended on the type of stent graft. Displacement during the cardiac cycle was greatest in a fenestrated device and smallest in a chimney graft sac anchoring endosystem, with maximum displacement varying from 0.0 to 1.4 mm. There was no substantial displacement measurable in the spine.

CONCLUSIONS

A novel methodology to quantify and visualise stent graft motion in multiphasic ECG gated CT has been validated in vitro and tested in vivo. This methodology enables further exploration of in situ motion of different stent grafts and branch stents and their interaction with native vessels.

Endovascular Treatment of Complex Aneurysms with the Use of Covera Stent Grafts

PURPOSE

To characterize the short-term results of a newly available self-expanding covered stent (Covera; CR Bard Peripheral Vascular Inc., Murray Hill, New Jersey) for the reconstruction of target vessels in complex aneurysms.

MATERIALS AND METHODS

From August 2017 to November 2018, this self-expanding covered stent was used in 17 patients (mean 72.6 ± 7.6 years of age) during endovascular aneurysm repair (EVAR) with hypogastric preservation (11.8%), branched EVAR (29.4%), fenestrated (F)-EVAR (17.6%), chimney + F-EVAR (11.8%), or chimney EVAR (29.4%). In more than 48 stented arteries (2.8 ± 1.1/patient), 25 were preserved using this self-expanding covered stent.

RESULTS

All target vessels were successfully preserved. There was no 30-day mortality and 1 in-hospital death. Intraoperative aneurysm exclusion was successful in 14 patients (82.4%) with a perioperative technical success rate of 82.4%. The actuarial survival rate was 93.8% at 6 months and 85.9% at 12 months. Aneurysm sac regression of >5 mm was observed in 4 cases (23.5%), and the sac remained stable in the remaining patients (13 cases [76.5%]). At 12 months, the primary clinical success rate was 76.5%, and assisted primary clinical success rate was 82.4%. No type 3 endoleak was related to a disruption of the reconstruction with the self-expanding covered stent.

CONCLUSIONS

This new self-expanding covered stent provides good short-term patency in chimneys, branches, or fenestrations. Larger series with long-term follow-up are required to determine if the stent can sustain the mechanical stress to which it will be submitted in these repairs.

Chimney Stent Graft Technique for Endovascular Repair of Penetrating Atherosclerotic Ulcers of Abdominal Aorta with Bilateral Common Iliac Artery Aneurysms and Ectopic Right Renal Artery Stenosis

Ectopic renal artery (RA), a rare congenital anomaly, presents a challenge in open surgery and endovascular repair for abdominal aortic lesions. To preserve the abnormal main blood supply and renal function complicates the procedures requiring careful imaging measurement and well-designed therapeutic strategy. We report on a 68-year-old man with abdominal aortic atherosclerotic ulcers, bilateral common iliac artery aneurysms, and right ectopic RA stenosis that was successfully managed with antegrade chimney technique, resulting in well-excluded lesions and well-reconstructed renal blood supply without any complication. This endovascular procedure may be useful for repair of abdominal aortic lesions with ectopic RA in high-risk surgical patients.

Impact of secondary interventions on mortality after fenestrated branched endovascular aortic aneurysm repair

BACKGROUND

Fenestrated and branched endovascular aortic repair (F/BEVAR) is increasingly used to manage pararenal and thoracoabdominal aortic disease (TAAA). Device-related reintervention after F/BEVAR is common, but little is known about its impact on postoperative mortality. The purpose of this analysis was to describe secondary intervention (SI) after F/BEVAR and determine the impact of these procedures on patient survival.

METHODS

A single-center review was done on all consecutive F/BEVARs performed from 2010 to 2016. Primary end points were incidence of secondary aortic, branch, and/or access vessel‒related SI, and survival. SI was categorized as minor endovascular (branch restenting, access vessel treatment, or percutaneous coil embolization), major endovascular (new aortic graft placement), or open (bleeding, access vessel, and/or aortic). Kaplan-Meier methodology was used to estimate freedom from SI and survival. Multivariable analysis was used to identify predictors of SI.

RESULTS

A total of 308 F/BEVAR procedures were performed (75% physician-modified, 18% custom, 7% Zfen), with 1022 vessels revascularized (celiac, 228; superior mesenteric artery [SMA], 263; renal, 525). There were 117 (39%) extent I-III TAAA, 132 (44%) extent IV TAAA/4-vessel pararenal, and 54 (18%) <4-vessel pararenal repairs performed. Any type of SI occurred in 24% (74) of patients during the mean follow-up of 20 ± 21 months. The majority of reinterventions were endovascular (minor, 53% [n = 39]; major, 32% [n = 24]), whereas 12% (n = 9) were open and 3% (n = 2) hybrid. Primary indication for SI included: 22 (29%) with branch-related endoleaks (1C or III); 15 (22%) with proximal or distal aortic degeneration; 8 (12%) with branch vessel thrombosis/stenosis; 10 (11%) with aortic device type III endoleak/loss of overlap; 4 (6%) with postoperative mesenteric or renal bleeding events; 5 (5%) with type II endoleak; 3 (5%) with access vessel complication; and 2 (3%) with graft infection. Most SIs were elective (65%; n = 48) with the remainder occurring emergently (24%; n = 18) or for symptoms/urgently (11%; n = 8). Compared with endovascular remediation, open SI was more likely to be emergent (89%, 8 of 9; P = .001). Freedom from SI was 80 ± 3% and 64 ± 4% at 1 and 3 years, respectively. One- and 5-year survival with or without SI was: 1 year, 88 ± 4% vs 81 ± 3%; 5 years, 76 ± 5% vs 59 ± 4% (log rank test, P = .06). There was no survival difference based on type of SI (log rank test, P = .3). Extent I-III TAAA (HR, 1.6; 95% CI, 0.98-3.3; P = .06) and history of cerebrovascular disease (HR, 1.8; 95% CI, 0.97-2.6; P = .07) were predictive of SI.

CONCLUSIONS

SIs after F/BEVAR most frequently involve branch vessel or aortic device remediation procedures; however, they do not negatively impact out-of-hospital survival. These results further highlight the crucial role of imaging surveillance after F/BEVAR to maintain durability. Discussions with patients, periprocedural planning, and the next generation of device design must focus on issues surrounding the risk of device-related SI events.

Long-term durability of a physician-modified endovascular graft

We present a unique assessment confirming the long-term durability of a physician-modified endograft deployed as part of an Investigational Device Exemption clinical trial (NCT# 01538056). After receiving an intact postmortem aorta 7 years after the index procedure, we performed microcomputed tomography, necropsy, and metallurgical analysis on the specimen. Microcomputed tomography showed a single strut fracture not noted during previous surveillance. Necropsy revealed no graft fabric compromise, and examination of all three visceral fenestrations showed excellent alignment with no evidence of degradation. Analysis of the strut fracture implicated an initially small, fatigue-induced crack that likely succumbed during postmortem handling.

Using the Idea, Development, Exploration, Assessment, Long-Term Study Framework for Devices (IDEAL-D) to Better Understand the Evolution of Evidence Surrounding Fenestrated Abdominal Aortic Endovascular Grafts

The use of fenestrated endovascular devices for repair of complex aortic aneurysms has increased to nearly 5,000 implantations annually among Medicare patients in the United States in recent years. Given that nearly all aspects of treatment for minimally invasive aortic intervention rely on medical devices to better care for patients with vascular disease, clearly understanding how new and innovative technology evolves over the life cycle of a medical device is an essential skill set for cardiovascular physicians. Despite the need for this understanding, there is no standard framework upon which cardiovascular physicians, regulators, and patients can rely on to better understand the evolution of evidence from product inception through adoption and long-term effectiveness evaluation. As the aforementioned devices are increasingly and broadly used, the need for a formal framework for regulation and device approval has emerged. The goal of this review is to describe the Idea, Development, Exploration, Assessment, Long-term Study Framework for Devices (IDEAL-D). This framework is a model developed recently by an international panel of experts dedicated to better understanding the data steps necessary to bring a device from idea to routine practice and further to marketing, approval, and monitoring. In this review, we use the example of fenestrated endovascular aortic devices to illustrate the IDEAL-D framework, how it can help cardiovascular physicians improve their understanding of new technology, and the evidence which surrounds it from inception to long-term use.

Multicenter Registry about the Use of EndoAnchors in the Endovascular Repair of Abdominal Aortic Aneurysms with Hostile Neck Showed Successful but Delayed Endograft Sealing within Intraoperative Type Ia Endoleak Cases

BACKGROUND

The durability of endovascular aortic aneurysms repair (EVAR) is highly related to several anatomical constraints. The term "hostile neck" describes several anatomical features that usually make EVAR treatment technically demanding despite having higher risk of failure. The aim of the study was to describe a multicenter experience with EVAR and an adjunctive use of EndoAnchors in hostile neck anatomies.

METHODS

Data were prospectively collected from 4 academic vascular centers including 46 patients with a hostile neck treated by standard EVAR with the adjunctive use of EndoAnchors. Twenty-two of them (47.8%, group A) had an intraoperative type Ia endoleak, and 24 (52.2%) patients were treated in a preventive manner (group B). Primary endpoints were technical and procedural success. Secondary endpoints were regression of the aneurysm sac, freedom from type Ia endoleak, and reinterventions.

RESULTS

Neck length and diameter showed no statistical difference in preoperative measures, 9.1 ± 6.9 mm and 8.6 ± 2.8 mm and 25.4 ± 4.7 mm and 27.3 ± 4.7 mm, in group A and B, respectively. Aneurysm sac diameter decreased from 58.2 ± 8 mm and 57.9 ± 9.8 mm to 55.7 ± 8.5 mm and 53.8 ± 10.4 mm in group A and B; respectively, at the last computed tomography scan. Technical and procedural success was 97.8% and 100%, respectively, for group B. Group A showed persistence of type Ia endoleak at completion angiogram in 9 (40.9%) patients. Five of them showed early spontaneous sealing at the first (30 days) computed tomography angiography (CTA), and in the remaining 4, a delayed spontaneous sealing was diagnosed at 12-month CTA. No neck-related secondary procedures were performed. Overall survival was 91%.

CONCLUSIONS

Our study shows that additional use of EndoAnchors can successfully improve the sealing of abdominal endografts in case of intraoperative type Ia endoleaks in hostile neck anatomies, representing a safe and effective endovascular alternative in our armamentarium. However, meticulous radiological follow-up is necessary because complete resolution of all observed intraoperative type Ia endoleaks was not observed until the 12-month CTA follow-up.

A Study on the Pressure-Lowering Effect of the Multilayer Stent

BACKGROUND

The objective of the study was to investigate the hemodynamic changes of the blood flow in the aneurysm model after the multilayer stent placement using the fluid dynamic method, to analyze the effectiveness and properties of the multilayer stent in the treatment of aortic aneurysms.

METHODS

A water tank was filled with 5 L of experimental liquid after the circular flow pressure test platform with a glass aneurysm model, and a multilayer stent was built. Pressure at the middle part and the distal aneurysm neck part of the model was then measured. At each site, the pressure was measured 20 times at 1-min intervals, and the testing results were averaged for accuracy.

RESULTS

Without the stent, mean pressure at the middle part and at the distal aneurysm neck part of the model was 11.19 ± 0.23 Kpa and 13.31 ± 0.28 Kpa, respectively. With the stent, the mean pressure decreased to 10.60 ± 0.27 Kpa and 12.60 ± 0.29 Kpa, and the average difference was 0.59 ± 0.15 Kpa and 0.71 ± 0.15 Kpa, respectively.

CONCLUSIONS

After the placement of the multilayer stent, pressure inside the model at the middle part and distal neck part could both be diminished, yet the mean dropped pressure may be too small to be sufficient to cause significant impact on preventing the expansion of abdominal aortic aneurysm; therefore, the pressure-lowering effect of the multilayer stent for abdominal aortic aneurysm may not be ideal compared with the traditional covered stents.

Outcomes after endovascular repair of abdominal aortic aneurysm involving the renovisceral arteries: A multi-center follow-up study

Objectives

To evaluate outcomes after endovascular treatment of abdominal aortic aneurysms (AAA) involving the renovisceral arteries and to compare outcomes after fenestrated/branched endovascular aortic repair (f/b-EVAR), chimney/periscope EVAR (ch-EVAR), and bailout ch-EVAR.

Methods

A retrospective multicenter study including all patients with AAA involving the renovisceral segment, treated with f/b-EVAR, ch-EVAR, or bailout ch-EVAR, between 1 January 2005 and 30 June 2015, in three Swedish vascular centers. Patient charts were reviewed for data. Renovisceral stent graft patency was assessed on follow-up CT. Mortality was cross-checked against the Swedish Population Registry. Bailout ch-EVAR was defined as a perioperative decision of renovisceral endografting, as the artery was accidentally covered, or as the aneurysm neck sealing zone was considered inadequate.

Results

Of the 99 identified patients (76 men; mean age 74 years (range 58–89 years)), 68 underwent f/b-EVAR, 18 ch-EVAR, and 13 bailout ch-EVAR. Follow-up lasted for a median of 3.2 years (Q1, Q3 (2.1, 4.7 years)). Elective surgery comprised 87.9% ( n = 87) of the cases. Six patients died within 30 days, and the 30-day mortality after elective surgery was 4.6% (95% CI, 1.3%–11.4%) overall, 1.6% after f/b-EVAR (95% CI, 0.0%–11.4%), 15.4% after ch-EVAR (95% CI, 1.9%–45.4%), and 10.0% (95% CI, 0.3%–44.5%) after bailout ch-EVAR. During follow-up, there were 16 secondary interventions, of which 75% ( n = 12) were performed within six months after the primary intervention. Compared with f/b-EVAR, ch-EVAR was associated with a higher degree of type 1 endoleaks (1.5% vs. 22.2%, P = 0.001) and re-interventions during follow-up (13.2% vs. 33.3%, P = 0.046). The overall assisted target vessel patency was 96.1% (95% CI, 91.7%–98.6%) at one year and 95.2% (95% CI, 89.2%–98.4%) at two years.

Conclusions

Results after EVAR involving endografting of renovisceral arteries from three centers in Sweden with medium volumes are consistent with results previously reported from centers with larger volumes.

Rescue of proximal failure of endovascular abdominal aortic aneurysm repair with standard and fenestrated grafts

BACKGROUND

This study aimed to assess the outcomes of standard and fenestrated grafts to treat proximal failure of previous endovascular aneurysm repair (EVAR) in a tertiary referral center.

METHODS

All patients undergoing elective implantation of a standard or fenestrated graft after proximal failure of a previous EVAR between April 2010-November 2018 were included. Data were collected prospectively.

RESULTS

Fifty procedures were performed in 49 patients (45 male; mean age 74.6±7 years). A fenestrated proximal cuff was used in 24 (48%) cases, a composite bifurcated configuration in 21 (42%) cases, and EVAR in 5 (10%) cases. Technical success was achieved in all 5 EVAR cases and 41 of 45 FEVAR cases (91.1%). Iliac artery access problems due to the presence of the previous graft were encountered in eight (16%) procedures and renal artery catheterization difficulties in grafts with suprarenal fixation in seven (15.6%) procedures. There was one (2%) early death due to retroperitoneal bleeding. Early major complications occurred in three (6%) patients. Median follow-up was 26 months (range 1-77). Late occlusion occurred in two (1.3%) of the 151 targeted vessels. One patient needed permanent dialysis. Nine patients died during follow-up, one (2%) of them aneurysm-related. Ten (20.4%) patients presented with major complications during follow-up of which nine (18.4%) needed reintervention. Estimated freedom from reintervention at 1 and 3 years was 89.3±5.1% and 78.8±7.3%, respectively.

CONCLUSIONS

Repair with fenestrated grafts represents a safe and effective treatment option. Increased technical challenges are to be expected due to the previous graft.

Short- and Midterm Outcomes of Open Repair and Fenestrated Endografting of Pararenal Aortic Aneurysms in a Concurrent Propensity-Adjusted Comparison

Purpose: To compare outcomes of patients treated for pararenal aortic aneurysms using fenestrated endovascular aneurysm repair (fEVAR) vs open surgical repair (OSR) in 3 high-volume centers. Materials and Methods: A multicenter retrospective analysis was conducted of 200 pararenal abdominal aortic aneurysm patients electively treated with OSR (n=108) or fEVAR (n=92) from 1998 to 2015 at 3 tertiary institutions. Endpoints were 30-day morbidity and mortality, late reinterventions, visceral artery occlusion, and mortality. Analysis was conducted on the entire population and on a propensity score–matched population constructed on age, gender, coronary artery disease (CAD), and chronic renal failure. Results: In the total cohort, fEVAR patients were significantly (p<0.001) older and had higher frequencies of CAD (p<0.001) and previous stroke (p=0.003). OSR patients had higher risk of perioperative morbidity (OR 2.5, 95% CI 1.09 to 5.71, p=0.033), specifically respiratory failure (OR 4.06, 95% CI 1.12 to 4.72, p=0.034). These findings were confirmed in the propensity-adjusted analysis, where cardiac complications were also higher after OSR (OR 12.8, 95% CI 0.07 to 0.21, p=0.02). No difference in perioperative mortality (2.2% in fEVAR vs 1.9% in OSR) was identified. Mean follow-up was 50 months (range 0–119). Four-year results showed higher survival (91.2% vs 69.3%, p=0.02) and freedom from reintervention (95.6% vs 77.8%, p=0.01) after OSR in the unmatched population, with a small but significant (p=0.021) difference in the risk of late visceral artery occlusion/stenosis after fEVAR. On propensity analysis, no differences in late survival were found between groups. Conclusion: fEVAR and OSR may afford similar early and midterm survival rates. Higher risks of perioperative systemic complications after OSR are counterbalanced by higher risks of late visceral vessel patency issues and need for reintervention after fEVAR. Both procedures are safe and effective in the long term in experienced centers, where patient evaluation should drive the treatment strategy.

Midterm Single-Center Results of Endovascular Aneurysm Repair With Additional EndoAnchors

PURPOSE

To review midterm clinical outcomes of EndoAnchor placement during or after endovascular aneurysm repair (EVAR) or chimney EVAR (ch-EVAR).

MATERIALS AND METHODS

A retrospective analysis was conducted of 51 consecutive patients [median age 75 years; 38 men] who underwent EVAR/ch-EVAR with EndoAnchor placement between June 2010 and December 2016 to prevent seal failures (31, 61%) or to treat type Ia endoleak and/or migration (20, 39%). Median aortic neck diameter was 27.7 mm and median neck length was 9.0 mm. Thirty-three (65%) had a conical neck; 48 (94%) had at least 1 hostile neck characteristic. Thirty-two (63%) patients had severe comorbidities (ASA score ⩾III). Eight patients had a single ch-EVAR procedure. Baseline patient characteristics, anatomic variables, procedure details, early and late complications, reinterventions, and aneurysm-related and all-cause mortality rates were recorded. Follow-up imaging was performed with computed tomography angiography (CTA) or duplex ultrasonography.

RESULTS

Median procedure time was 100 minutes; a median of 6 EndoAnchors were implanted. There were 10 (10%) residual type Ia endoleaks at the end of the procedure; 9 had resolved by the first postoperative CTA. One residual and 2 new type Ia endoleaks were identified at the first postoperative imaging. Median follow-up for the entire cohort was 24.0 months, during which 3 new type Ia endoleaks were identified. Five of the 6 type Ia endoleaks were treated, 1 resolved spontaneously. There was 1 endograft limb occlusion without clinical consequences, 1 chimney graft occlusion without possibilities for a reintervention, 1 rupture after type IV endoleak (a Nellix device was successfully deployed within the main device), and 1 complete graft explantation for infection. There was no new-onset hemodialysis. Kaplan-Meier estimates of freedom from type Ia endoleak, proximal neck-related reinterventions, and aneurysm-related mortality at 2 years were 87.3%, 92.2%, and 94.0%, respectively.

CONCLUSION

EndoAnchors are helpful in the endovascular treatment of unfavorable proximal aortic necks, with fair midterm results.

Lessons learned and learning curve of fenestrated and branched endografts

Fenestrated and branched endovascular repair (F-BEVAR) has been increasingly used to treat patients with complex aortic aneurysms involving the renal-mesenteric arteries. As with any new procedure, there is a learning curve associated with mastering the technique. However, proficiency with deployment is only one aspect of the learning process, and ultimately, this curve is defined not by one quality parameter, but by patient selection, the performance of the entire team, the surgeon's ability to adapt to unexpected events, and the durability of the repair. This article reviews the importance of novel training paradigms, learning curve, and factors affecting outcomes of complex endovascular aneurysm repair.

The role of selective stenting for superior mesenteric artery scallops during fenestrated endovascular aneurysm repair

OBJECTIVE

Stenting of small fenestrations of the Zenith fenestrated endograft (ZFEN; Cook Medical, Bloomington, Ind) is necessary during fenestrated endovascular aneurysm repair (FEVAR) of complex abdominal aortic aneurysms to avoid malalignment. However, stenting of superior mesenteric artery (SMA) scallops of ZFEN devices is optional according to the instructions for use. The objective of this study was to assess the early and midterm outcomes of selective use of stents in SMA scallops of ZFEN during FEVAR procedures.

METHODS

This study is a single-institution retrospective review of prospectively enrolled patients treated at the University of North Carolina at Chapel Hill between July 2010 and August 2014. Only patients with SMA scallops were included for analysis. We compared results between patients grouped as stented or unstented SMA scallops. The scallops were stented when one or more of the following criteria were present: misalignment of scallop determined by balloon testing intraoperatively; configuration consisting of an SMA scallop and a single renal fenestration or stent; and pre-existing stenosis in the vessel adjacent to the graft scallop. The study was approved by the local Institutional Review Board. Primary outcomes addressed were mortality, vessel patency, early and late complications, and reintervention rates. Baseline characteristics of the patients and procedure data were also described.

RESULTS

During the 48-month study period, 61 patients were treated for complex abdominal aortic aneurysms at the University of North Carolina with a mean age of 73 years, and 74.3% of patients were male. Thirty-nine of 61 patients (63.9%) had a device design with an SMA scallop and were included for analysis. Eleven of 39 patients (28%) had the SMA primarily stented and 28 (72%) were unstented. There was only one death (2.5%) during the 30-day postoperative period, with 100% technical success and branch patency. In the unstented group, there were three SMA complications during follow-up, two requiring reintervention; however, there were no associated deaths. Among the stented group, there was one branch-related complication that occurred during the procedure but no stent stenosis or occlusion during the long-term follow-up. During the mean follow-up period of 21.7 months, no SMA stent thrombosis occurred. There was no statistical difference in outcomes between groups.

CONCLUSIONS

Single-wide SMA scallops of ZFEN during FEVAR procedures may be selectively stented using specific criteria and rigorous follow-up, without compromising the safety and efficacy of the SMA.

Practice Patterns of Fenestrated Aortic Aneurysm Repair: Nationwide Comparison of Z-Fen Adoption at Academic and Community Centers Since Commercial Availability

Context:

Over the past decade, a number of endovascular approaches have evolved to treat aortic aneurysms with anatomy that is not amenable to traditional endovascular repair, although the optimal practice and referral patterns remain in question. The Zenith fenestrated (Z-Fen) endograft (Cook Medical) represents the first commercially available fenestrated graft product in the United States.

Objective:

We aim to quantify practice patterns in Z-Fen use during the first 5 years of commercial availability, and we identify predictors of high and low uptake.

Design, Setting, and Patients:

This is a retrospective review of complete order records for Z-Fen endografts since June 2012. We performed univariate and multivariate regressions of predictors that surgeons and centers would be in the top and bottom quartiles of annual Z-Fen use.

Results:

Since June 15, 2012, 744 surgeons have been trained to use Z-Fen, and 4133 cases have been performed at 409 trained centers. The average annual number of cases per trained surgeon was 4.46 [95% confidence interval (CI), 3.58-5.70]; however, many surgeons performed few or no cases following training, and there was a skew toward users with low average annual volumes (25th percentile 1.23, 50th percentile 2.35, 75th percentile 4.93, and 99th percentile 33.29). Predictors of high annual use in the years following training included academic center (aOR 5.87, P = .001) and training within the first 2 years of availability (aOR 46.23, P < .001).

Conclusion:

While there is literature supporting the safety and efficacy of Z-Fen, adoption has been relatively slow in an era when the vast majority of vascular surgeons have advanced endovascular skills. Given the training and resources required to use fenestrated or branched aortic endovascular devices, referral patterns should be determined and training should be focused on centers with high expected volumes.

Custom-Made Endograft for Endovascular Repair of Thoraco-Abdominal Aneurysm and Type B Dissection: Single-Centre Experience

AIMS

To report a series of patients treated with the Jotec custom-made endograft for thoraco-abdominal aneurysms and dissections and identify predictive factors for re-intervention.

METHODS

We retrospectively analysed 49 patients unsuitable for surgery, treated between 2011 and 2017 (71.3 ± 9.5 years; 15 females). Indications included Crawford type 4 aneurysm in 25 patients, type 3 in 13, type 2 in 4, type 1 in 2 and chronic aneurysmal dilatation of the false lumen following dissection in 5 cases. Mean aneurysm diameter was 58.7 ± 8.4 mm. The study aims were to assess procedural success, complications rate, mortality and long-term follow-up. We also analysed factors that predicted the need for re-intervention.

RESULTS

The endograft was successfully deployed in all patients, catheterization of the fenestration and/or branches was achieved in 152/156 (97.4%) vessels. Early complications occurred in 10 patients (3 paraplegia, 3 haemorrhages, pancreatitis, aortic rupture, iliac artery rupture, 2 strokes). Thirty-day mortality was 10.2% and 180-day mortality 14.3%; two non procedure related deaths occurred. Mean follow-up was 23.6 ± 29.9 months [range 1-80]. No patients needed surgical explantation or developed significant renal impairment. Endoleak rate was 34.6% and re-intervention rate 9.7%. The aneurysm sac reduced or was stable in 36/49, and enlarged in 9/49 patients prompting re-intervention. Primary, primary-assisted and secondary patency of fenestrations/branches at 80 months was 90, 96 and 100%. Re-intervention was required more frequently in braches than in fenestrations, most commonly the external type branches.

CONCLUSIONS

The results of the Jotec endograft are comparable to other devices, with acceptable complication and re-intervention rates. Fenestration and inner-branch should be preferred due to lower re-intervention rates.

Decision uncertainty and value of further research: a case-study in fenestrated endovascular aneurysm repair for complex abdominal aortic aneurysms

Background

Fenestrated endovascular aneurysm repair (fEVAR) is a new approach for complex abdominal aortic aneurysms, limited to a few specialist centers, with limited evidence base. We developed a cost-effectiveness decision model of fEVAR compared to open surgical repair (OSR) to investigate the likely direction of costs and benefits and inform further research projects on this technology.

Methods

A systematic review with meta-analysis and a four-state Markov model were used to estimate the cost-effectiveness of fEVAR versus OSR. We used a recent coverage with evidence development framework to characterize the main sources of uncertainty and inform decisions about the type of further research that would be most worthwhile and feasible.

Results

Seven observational comparative studies were identified, of which four presented odds ratios adjusted for confounders. The odds ratios for operative mortality varied widely between studies. Assuming a central estimate of the odds ratio of 0.54 (95% CI 0.05–6.24), the decision model estimated that the incremental cost per quality adjusted life year (QALY) was £74,580/QALY with a probability of 9 and 16% of being cost-effective at standard cost-effectiveness thresholds of £20,000/QALY and £30,000/QALY, respectively. The Expected Value of Perfect Information over 10 years at a threshold of £20,000/QALY was £11.2 million. Operative mortality contributed to most of the uncertainty in the decision model.

Conclusions

In the case of “maturing technologies”, decision modelling indicates the likely direction of costs and benefits and guides the development of further research projects. In our analysis of fEVAR versus OSR, decision uncertainty, particularly around operative mortality, might be effectively resolved by a short-term RCT, or possibly a well-conducted comparative observational study. Decision makers may consider that a conditional coverage decision is warranted with assessments required to make this type of recommendation depending on local priorities and circumstances.

Electronic supplementary material

The online version of this article (10.1186/s12962-018-0098-7) contains supplementary material, which is available to authorized users.

Complications and Reinterventions After Fenestrated and Branched EVAR in Patients with Paravisceral and Thoracoabdominal Aneurysms

The application of endovascular strategies to treat aneurysms involving the abdominal and thoracoabdominal aorta has evolved significantly since the inception of endovascular aneurysm repair. Advances in endograft technology and operator experience have enabled the management of a wider spectrum of challenging aortic anatomy. Fenestrated endovascular and branched endovascular aneurysm repair represent two technical innovations, which have expanded endovascular treatment options to include patients with paravisceral and thoracoabdominal aortic aneurysms. Although similar in many ways to standard aortic endografts, fenestrated and branched endografts have specific short- and long-term complications due to their unique modular endograft design and their sophisticated deployment mechanisms. This article aims to examine the commonly encountered complications with these devices and the endovascular reintervention strategies.

Snorkel Technique for Inferior Mesenteric Artery During Endovascular Repair of Abdominal Aortic Aneurysm

PURPOSE

The snorkel technique is commonly used to preserve renal arteries in juxta renal aneurysm during endovascular repair. Herein, we present a patient who underwent bifurcated endograft implantation with snorkel technique for inferior mesenteric artery (IMA) in order to preserve the major source of bowel circulation.

CASE REPORT

A 69-year-old male patient was diagnosed with abdominal aortic aneurysm. His history revealed that he had bowel resection due to a car accident 30 years ago. In addition, he was given relaparotomy 4 times due to intestinal complications. Computed tomography showed fusiform aneurysm with a maximal diameter of 60 mm and chronical occlusion of the superior mesenteric artery. Inferior mesenteric artery was found to be hypertrophic. During EVAR, 6 mm × 10 cm covered VIABAHN Endoprosthesis (Gore Medical) was implanted to the IMA over a 0.018 guidewire via puncture of the left axillary artery. Initially, the main body of the aortic stent-graft (Gore C3, size 23-14-16) was implanted to the infra renal segment of the aorta (below the renal arteries and the orifice using VIABAHN) via the right femoral artery. Next, the contralateral leg (Gore, 14-12-00) was implanted. Computed tomography was examined at 1- and 32-month postoperatively, and no endoleak or patency of IMA stent was detected.

CONCLUSION

In this case of IMA-dependent circulation of the intestinal system, the protection of IMA via snorkel technique was successful.

Computed tomography angiography-fluoroscopy image fusion allows visceral vessel cannulation without angiography during fenestrated endovascular aneurysm repair

BACKGROUND

Fenestrated endovascular aneurysm repair (FEVAR) is an evolving technique to treat juxtarenal abdominal aortic aneurysms (AAAs). Catheterization of visceral and renal vessels after the deployment of the fenestrated main body device is often challenging, usually requiring additional fluoroscopy and multiple digital subtraction angiograms. The aim of this study was to assess the clinical utility and accuracy of a computed tomography angiography (CTA)-fluoroscopy image fusion technique in guiding visceral vessel cannulation during FEVAR.

METHODS

Between August 2014 and September 2016, all consecutive patients who underwent FEVAR at our institution using image fusion guidance were included. Preoperative CTA images were fused with intraoperative fluoroscopy after coregistering with non-contrast-enhanced cone beam computed tomography (syngo 3D3D image fusion; Siemens Healthcare, Forchheim, Germany). The ostia of the visceral vessels were electronically marked on CTA images (syngo iGuide Toolbox) and overlaid on live fluoroscopy to guide vessel cannulation after fenestrated device deployment. Clinical utility of image fusion was evaluated by assessing the number of dedicated angiograms required for each visceral or renal vessel cannulation and the use of optimized C-arm angulation. Accuracy of image fusion was evaluated from video recordings by three raters using a binary qualitative assessment scale.

RESULTS

A total of 26 patients (17 men; mean age, 73.8 years) underwent FEVAR during the study period for juxtarenal AAA (17), pararenal AAA (6), and thoracoabdominal aortic aneurysm (3). Video recordings of fluoroscopy from 19 cases were available for review and assessment. A total of 46 vessels were cannulated; 38 of 46 (83%) of these vessels were cannulated without angiography but based only on image fusion guidance: 9 of 11 superior mesenteric artery cannulations and 29 of 35 renal artery cannulations. Binary qualitative assessment showed that 90% (36/40) of the virtual ostia overlaid on live fluoroscopy were accurate. Optimized C-arm angulations were achieved in 35% of vessel cannulations (0/9 for superior mesenteric artery cannulation, 12/25 for renal arteries).

CONCLUSIONS

Preoperative CTA-fluoroscopy image fusion guidance during FEVAR is a valuable and accurate tool that allows visceral and renal vessel cannulation without the need of dedicated angiograms, thus avoiding additional injection of contrast material and radiation exposure. Further refinements, such as accounting for device-induced aortic deformation and automating the image fusion workflow, will bolster this technology toward optimal routine clinical use.

Evaluation of CT Angiography Image Quality Acquired with Single-Energy Metal Artifact Reduction (SEMAR) Algorithm in Patients After Complex Endovascular Aortic Repair

Purpose

To evaluate the value of single-energy metal artifact reduction (SEMAR) algorithm on image quality in patients after complex endovascular aortic repair (EVAR) with fenestrated and branched devices.

Methods

Routine follow-up computed tomography angiography (CTA) examinations were performed between February 2016 and May 2017 in 18 patients who underwent a complex EVAR procedure at our institution. Objective analysis was performed by measuring the standard deviation (SD) of attenuation (Hounsfield Units), and the contrast-to-noise ratio (CNR) in regions of interests in the stented visceral arteries. Subjective analysis of the degree of artifacts and stent visualization was performed independently by two interventional radiologists, blinded to the image reconstruction.

Results

The SD of attenuation was significantly lower in all target visceral arteries (p < .001), the celiac artery (p = .002), the superior mesenteric artery (SMA; p = .043), and renal arteries (p < .001) in the CT images with SEMAR reconstruction. The CNR significantly increased in all SEMAR-reconstructed target visceral arteries (overall: p < .001, celiac artery: p = .009; SMA: p = .003; renal arteries: p < .001). The reviewers rated a significantly lower artifact degree in all target vessels (overall: p < .001, celiac artery: p = .001; SMA: p = .008; renal arteries: p < .001) and a significantly improved visualization of the stent patency in all target vessels (overall: p < .001, celiac artery: p = .031; SMA: p = .047; renal arteries: p < .001) in the SEMAR images. Overall preference of both reviewers was in favor of the SEMAR reconstruction in 15/18 cases (83%).

Conclusion

Reconstruction with SEMAR algorithm significantly improves CTA image quality in patients after complex EVAR.

Level of Evidence

Level 4, Case series.

Complications and Perioperative Management of Patients Undergoing Thoracic Endovascular Aortic Repair

Endovascular treatments have become increasingly common for patients with a variety of thoracic aortic pathologies. Although considered less invasive than traditional open surgical approaches, they are nonetheless complex procedures. Patients undergo manipulation of an often calcified aorta near the origin of the carotid and subclavian vessels and have stents placed in a curved vessel adjacent to a perpetually beating heart. These stents can obstruct blood flow to the spinal cord, induce an inflammatory response, and in rare cases erode into the adjacent trachea or esophagus. Renal complications range from contrast-induced nephropathy to hypotension and ischemia to dissection. Emboli can lead to strokes and mesenteric ischemia. These patients have complex medical histories, and skilled perioperative management is critical to achieving the best clinical outcomes. Here, we review the medical management of the most common complications in these patients including stroke, spinal cord ischemia, renal injury, retrograde dissections, aortoesophageal and aortobronchial fistulas, postimplantation syndrome, mesenteric ischemia, and endograft failure.

Medium-term outcomes of fenestrated endovascular repair of juxtarenal abdominal aortic aneurysms

BACKGROUND

Abdominal aortic aneurysms pose a substantial clinical burden, and a significant proportion are not anatomically suitable for open repair or standard endovascular aneurysm repair (EVAR), instead requiring fenestrated EVAR (fEVAR). We sought to compare clinical outcomes and trends over time in patients undergoing fEVAR in Australia.

METHODS

We conducted a retrospective analysis of all patients undergoing fEVAR at a tertiary referral centre between 2010 and 2015, including outcomes and complications, both as inpatients and after discharge.

RESULTS

Thirty-nine patients underwent fEVAR during the study period, with mean age of 75 years and mean aneurysm size of 61 mm. One hundred and thirty-four target vessels were treated and inhospital mortality was 5% (two patients). There were nine inhospital, eight Type II and one Type III endoleaks. Ten patients suffered acute kidney injury, one of whom required dialysis. Mean follow-up was 14.5 months (range: 0-46.7). Target vessel patency was 99.2% at follow-up. There were six Type II endoleaks at follow-up, and two patients died during the follow-up period (of non-aneurysm-related causes).

CONCLUSION

fEVAR is an effective treatment with low morbidity and mortality, and we have demonstrated excellent survival and target vessel patency at a mean follow-up of 14 months. Endoleak rates were low, despite the high complexity of the aneurysms treated.