Trends in hospitalization of patients undergoing endovascular treatment of thoracoabdominal aortic aneurysms based on cerebrospinal fluid drainage strategy

OBJECTIVE

The aim of this study was to identify trends in hospital (HLOS) and ICU (ICULOS) lengths of stay, and the relationship with cerebrospinal fluid drainage (CSFD) protocols in patients undergoing fenestrated-branched endovascular aortic repair (FB-EVAR) of thoracoabdominal aortic aneurysms (TAAAs).

METHODS

A retrospective review of patients who underwent elective FB-EVAR for extent I-IV TAAAs between 2008-2023 at a single aortic center of excellence was conducted. Patient demographics, cardiovascular comorbidities, surgical risk, technical details, CSFD strategy (prophylactic or therapeutic), procedural success, and perioperative outcomes were collected. Patients were divided into two groups based on CSFD protocol. Group 1 included patients treated before 2020 when prophylactic CSFD was performed widely, and Group 2 consisted of patients treated since 2020 with therapeutic CSFD. Primary endpoints were HLOS, ICULOS, major adverse events (MAE), and perioperative mortality.

RESULTS

FB-EVAR was performed in 702 patients; 412 underwent elective TAAA repair and were included in the analysis. Mean age was 73 years (SD±8) and 68% were males. Patient-specific manufactured devices were used in 252 patients (61%), physician-modified endografts in 110 (27%), and 50 patients (12%) were treated with off-the-shelf devices. Demographics, aneurysm extent, MAE (including spinal cord ischemia), and mortality were similar in both groups. A significant reduction in mean HLOS between the groups (9±9. vs 6±5 days, p = .02) coincided with decreased use of prophylactic CSFD (70% vs 1.2%, p < .001), with similar rates of SCI (7.6% vs 4.9%, p = .627) and ICULOS (3±3 vs 2.5±3, p = .19). Patients in the therapeutic drainage cohort (group 2) had a higher incidence of congestive heart failure (24% vs 11%, p = .003), hypercholesterolemia (91% vs 80%, p = .015), COPD (55% vs 37%, p = .004), and peripheral artery disease (39% vs 19%, p < .001) compared to group 1, suggesting treatment of a more complex patient cohort. On adjusted multivariable analysis accounting for ASA score, comorbidities, and device type, the difference in HLOS remained statistically significant (p = .01).

CONCLUSION

HLOS decreased over time in patients undergoing FB-EVAR for TAAA following transition from prophylactic to therapeutic CSFD protocol. This transition was the only modifiable, independent risk factor for shorter HLOS, without an increase in SCI, albeit with similar ICULOS.

The Impact of the Proctor Assistance for a Safe Learning Curve in the Development of a Complex Aortic Endovascular Program

INTRODUCTION

Initiating an endovascular aortic program for treatment of complex aortic aneurysms with fenestrated and branched grafts (FB-EVAR) is challenging. Using a Proctor is one option for training and development of the team. However, this approach has not been formally analyzed. The aim of this study was to analyze the learning curve and the effect of the Proctor regarding safety and effectiveness in FB-EVAR.

METHODS

A single-center retrospective cohort study was performed, including all consecutive elective patients submitted to FB-EVAR (including both thoraco-abdominal-TAAA and complex abdominal aortic aneurysms-C-AAA) from 2013 to 2021. Patients were divided into 2 groups, the first operated with the Proctor present and the second without. Primary outcomes were 30-day mortality (safety) and technical and procedure success (efficacy). Secondary outcomes included treatment performance (procedure time, blood loss, contrast, and radiation use), re-interventions, aneurysm shrinking, target vessel patency, 30-day mortality, aneurysm-related mortality, and overall mortality.

RESULTS

Overall, 105 patients were included in the study, 35 operated with Proctor and 70 operated without. The first 20 patients were operated always with the Proctor, and the remaining were operated with the Proctor selectively. Mean age was 71.8 (±7.3) years and 95 patients were male (90.5%). Overall, 62 (65%) patients had C-AAA or extent IV TAAAs and 43 (35%) had extensive TAAAs. There were no significant differences regarding 30-day mortality (Log Rank=0.99), technical success (p=0.4), or procedure success (p=0.8). Mean surgical time was longer in the non-Proctor group (p=0.005), as well as significant intra-operative blood loss (p=0.042). Contrast use (p=0.5) and radiation (p=0.53) were non-significantly different between groups. There were no significant differences regarding length of stay (p=0.4), major adverse events (p=0.6), target vessel patency (Log Rank=0.97), early (p=0.7) and late endoleaks (0.7), aneurysm shrinking (p=0.6), re-interventions (p=0.2), and overall mortality (Log Rank=0.87).

CONCLUSION

In our experience, the use of a Proctor to start and accompany our complex endovascular aortic program for FB-EVAR was both safe and effective and may serve as a template by other countries and centers that aim to developing their programs.

A Systematic Review and an Updated Meta-Analysis of Fenestrated/Branched Endovascular Aortic Repair of Chronic Post-Dissection Thoracoabdominal Aortic Aneurysms

The objective of this study is to present the current outcomes of fenestrated/branched endovascular repair (F/BEVAR) for post-dissection thoracoabdominal aortic aneurysms (PDTAAAs). A systematic review of the literature according to PRISMA guidelines up to October 2023 was conducted (protocol CRD42023473403). Studies were included if ≥10 patients were reported and at least one of the major outcomes was stated. A total of 10 studies with 585 patients overall were included. The pooled estimate for technical success was 94.3% (95% CI 91.4% to 96.2%). Permanent paraplegia developed with a pooled rate of 2.5% (95% CI 1.5% to 4.3%), whereas a cerebrovascular event developed with a pooled rate of 1.6% (95% CI 0.8% to 3.0%). An acute renal function impairment requiring new-onset dialysis occurred with a pooled rate of 2.0% (95% CI 1.0% to 3.8%). Postoperative respiratory failure was observed with a pooled estimate of 5.5% (95% CI 3.8% to 8.1%). The pooled estimate for 12-month overall survival was 90% (95% CI 85% to 93.5%), and the pooled estimates for 24-month and 36-month survival were 87.8% (95% CI 80.9% to 92.5%) and 85.5% (95% CI 76.5% to 91.5%), respectively. Freedom from reintervention was estimated at 83.9% (95% CI 75.9% to 89.6%) for 12 months, 82.8% (95% CI 68.7% to 91.4%) for 24 months and 76.1% (95% CI 60.6% to 86.8%) for 36 months. According to the present findings, F/BEVAR can be performed in PD-TAAAs with high rates of technical success and good mid-term results.

Utility of 4D CT in endoleak characterization after advanced endovascular aortic repair

OBJECTIVES

To assess the performance of dynamic or 4D CT in characterizing endoleaks in advanced endovascular aortic repair (branched and fenestrated) when other modalities fail to fully characterize the leak, most often conventional CTA.

METHODS

Retrospective review of 13 patients from 2008 to 2021 who underwent 16 4D CTs to characterize endoleaks in branched and fenestrated endovascular aortic repair (FB-EVAR). The 4D CTs were performed covering up to 16 cm of the z-axis, with anywhere between 10 and 40 iterations performed every 2 s. These settings were adjusted depending on graft characteristics and type of endoleak suspected. The scans were assessed for their ability to detect the endoleak (sensitivity), and further to characterize the endoleak by type and subtype (specificity).

RESULTS

Overall sensitivity in 16 scans for endoleak detection was 100%. There was a specificity of 87.5% for determining the type of endoleak (14/16). These results included two studies that were inconclusive and repeated due to technical difficulties. In patients where a specific subtype was not established, the leak was localized to the appropriate target vessel. Average dose for the 4D CT was 4724 mGy*cm (1108-11069), with the outlining higher dose scans secondary to higher iterations in those scans.

CONCLUSIONS

4D CT is a useful adjunctive tool in FB-EVAR surveillance with excellent sensitivity and specificity in characterizing endoleaks. This allows for accurate localization of leaks, which is critical for management planning.

Salvage of an Incomplete Sandwich With a Covered Celiac Trunk and a "Floating" Superior Mesenteric Artery Stent in a Thoracoabdominal Aortic Aneurysm

PURPOSE

To report a case of a patient with a large thoracoabdominal aortic aneurysm (TAAA) extent V treated with a custom-made fenestrated and branched endovascular repair (F/B-EVAR) after a failed and incomplete attempt of a Sandwich repair technique.

REPORT

An 83-year-old patient was referred to our department after a failed attempt at endovascular repair of type V TAAA with a sandwich technique. The celiac trunk was inadvertently covered with the first endograft and a covered long superior mesenteric artery stent was placed and left facing upward inside the aorta. We performed a staged repair, by first catheterizing and stenting the celiac trunk and bringing it under and inside the main aortic endograft. In interval, a F/B-EVAR was performed using a bimodular custom-made device (CMD) with a proximal 2 branch module for the celiac trunk and superior mesenteric artery and distal module with fenestrations for both renal arteries. The intervention was successful, and the follow-up was uneventful at 6 months.

CONCLUSIONS

Re-intervention after failed endovascular attempts of TAAA repair are technically challenging and require advanced endovascular techniques. The ability to construct CMDs allowed to extend repair to our patient which had severe anatomical constraints for other techniques.

[Secondary ruptures of an abdominal aortic aneurysm treated with a physician-modified fenestrated endograft, endoanchors and finally with open repair]

Secondary rupture is a late complication of endovascular aneurysm repair (EVAR). Open surgery is a technically feasible treatment option in most cases, however, late conversion carries a significant risk of morbidity and mortality, as it usually requires at least partial explantation of the in situ device, which is of major concern especially if suprarenal fixation is present. Endovascular treatment of these cases is usually challenging, especially since the custom-made devices that are often needed are not readily available but having a production time of several weeks. To overcome this limitation, physician-modified stent grafts are getting accepted to treat such urgent cases. We present the case of a patient receiving EVAR who later experienced two ruptures, treated first with a physician-modified endograft and adjunctive endoanchoring, later with open ligation of the lumbar arteries. Orv Hetil. 2023; 164(36): 1426-1431.

Can the Fenestrated Anaconda™ salvage failed competitor endografts? An international frame of reference

INTRODUCTION

An abdominal aortic aneurysm (AAA) is a life-threatening abnormal dilation of the abdominal aorta that can be repaired either endovascularly or with open surgery. However, endovascular aortic repair (EVAR) has become the main treatment modality for AAA due to its more optimal results. EVAR devices can either be standard, fenestrated, or branched, with fenestrated EVAR (FEVAR) seemingly achieving superior prospects. Although EVAR is associated with excellent outcomes, it still carries a risk of certain complications requiring reintervention or 'rescue'. Several commercial EVAR devices are available on the global market, nevertheless, the Fenestrated Anaconda developed by Terumo Aortic can be considered the superior device due to the wide range of endovascular solutions that it offers along with its unique custom-made approach, excellent results and its highly promising potential to be used as a 'rescue' device for failed competitor endografts.

MATERIALS AND METHODS

The current study represents a 9-year cross-sectional international analysis of a custom-made Fenestrated Anaconda™ device. For the statistical analysis, SPSS 28 for Windows and R were utilised. Pearson Chi-square analysis was used to assess differences in cumulative distribution frequencies between select variables. Statistical significance for all two-tailed tests was set at p < 0.05.

RESULTS

Out of 5058 EVARs performed using the Fenestrated Anaconda, 2987 (59%) were 'rescue' procedures for migrated Gore (n = 252) and Medtronic (n = 2735) devices. The Fenestrated Anaconda™ was indicated as the reintervention device either due to unsuitable/complex anatomy for the competitor (n = 2411) or based on surgeon preference (n = 576). Overall, the Fenestrated Anaconda was utilised to rescue 3466 (68.5%) failed previous EVARs using competitor devices. Yet, the primary endovascular solution offered by the Fenestrated Anaconda was FEVAR (91.3%), with 112 (2.2%) devices using custom-made iliac stents.

DISCUSSION

The use of the Fenestrated Anaconda endograft as a 'rescue' device to salvage failed competitor devices is well-established in the literature with excellent clinical outcomes achieved. The evidence in the literature also highlights the distinctive custom-made approach that the Fenestrated Anaconda offers which enables it to treat extremely complex aortic anatomy.

Systematic Review on Early and Follow-up Mortality Rate in Octogenarians Treated With a Fenestrated and/or Branched Endovascular Aortic Repair

PURPOSE

Advanced age has been related to conflicting outcomes after fenestrated/branched endovascular aortic aneurysm repair (F/BEVAR). The aim of this meta-analysis is to compare 30-day mortality, technical success, and 1-year and 5-year survival in octogenarians and non-octogenarians who underwent F/BEVAR for complex aortic aneurysms.

MATERIALS AND METHODS

This meta-analysis was pre-registered to PROSPERO (CRD42022348659). The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) 2020 statement was followed. A search of the English literature, via Ovid, using MEDLINE, Embase, and CENTRAL databases, until August 30, 2022, was executed. Randomized Control Trials and observational studies (2000-2022), with ≥5 patients, reporting on 30-day mortality and 1-year and 5-year survival rates among octogenarians and non-octogenarians after F/BEVAR were eligible. The Risk Of Bias In Non-Randomized Studies of Interventions (ROBINS-I) tool was applied to assess the risk of bias. The primary outcome was 30-day mortality and secondary was 1-year and 5-year survival in octogenarians and non-octogenarians. The outcomes were summarized as odds ratio (OR) with 95% confidence intervals (CIs). A narrative presentation was selected in case of missing outcomes.

RESULTS

The initial research isolated 3263 articles; 6 retrospective studies were finally included. A total of 7410 patients were managed with F/BEVAR; 1499 patients (20.2%) were ≥80 years old (75.5% males, 259/343). The estimated 30-day mortality was 6% among octogenarians vs 2% in younger patients, with a significantly higher 30-day mortality for patients ≥80 years old (OR 1.21, 95% CI 0.61-1.81; p=0.0.11; Ι²=36.01%). Technical success was similar between the groups (OR -0.83; 95% CI -1.74-0.07, p<0.0.001; Ι²=95.8%). Regarding survival, a narrative approach was decided due to missing data. Two studies reported a statistically significant difference in 1-year survival between groups, with higher mortality in octogenarians (82.5%-90% vs 89.5%-93%), while 3 reported a similar 1-year survival rate in both groups (87.1%-95% vs 88%-89.5%). At 5 years, 3 studies reported a statistically significant lower survival for octogenarians (26.9%-42% vs 61%-71%).

CONCLUSIONS

Octogenarians treated with F/BEVAR presented higher 30-day mortality while a lower survival rate at 1 and 5 years was reported in the literature. Patient selection is thus mandatory among older patients. Further studies, especially on patient risk stratification, are needed to estimate the F/BEVAR outcomes on elder patients.

CLINICAL IMPACT

Age may be a factor of increased early and long-term mortality within patients managed for aortic aneurysms. In this analysis, patients over 80 years old were compared to their younger counterparts when managed with fenestrated or branched endovascular aortic repair (F/BEVAR) . The analysis showed that early mortality was acceptable for octogenrains but significantly higher when compared to patients younger than 80 years. One-year survival rates are controversial. At 5-year follow-up, octogenarians present lower survival but data to provide metanalysis are lacking. Patient selection and risk stratification are mandatory in older candidates for F/BEVAR.

Endovascular Solutions for Abdominal Aortic Aneurysms: Fenestrated, Branched and Custom-Made Devices

BACKGROUND

Abdominal aortic aneurysm (AAA) has a prevalence of 4.8%. AAA rupture is associated with significant mortality, thus surgical intervention is generally required once the aneurysm diameter exceeds 5.5 cm. Endovascular aneurysm repair (EVAR) is the predominant repair modality for AAA. However, in patients with complex aortic anatomy, fenestrated or branched EVAR is a superior repair option vs standard EVAR. Fenestrated and branched endoprostheses can be off-the-shelf or custom-made, which offers a more individualised approach.

AIM

To summarise and evaluate the clinical outcomes achieved by fenestrated EVAR (FEVAR) and branched EVAR (BEVAR), and to explore the role of custom-made endoprostheses in contemporary AAA management.

METHODS

A literature search using Ovid Medline and Google Scholar was conducted to identify literature pertaining to the use and outcomes of fenestrated, branched, fenestrated-branched and custom-made endoprostheses for AAA repair.

RESULTS

FEVAR is an effective repair modality for patients with AAA that offers similar early survival, improved early morbidity but higher rates of reintervention in comparison to open surgical repair (OSR). Compared with standard EVAR, FEVAR is associated with similar in-hospital mortality yet higher rates of morbidity, especially regarding renal outcomes. BEVAR outcomes are rarely reported exclusively in the context of AAA repair. When reported, BEVAR is an acceptable alternative to EVAR in the treatment of complex aortic aneurysms and has similar reported complication issues to FEVAR. Custom-made grafts are a good alternative treatment option for complex aneurysms where hostile aneurysm anatomy precludes the use of conventional EVAR and sufficient time is available for the manufacturing of such devices.

CONCLUSION

FEVAR offers a very effective treatment for patients with complex aortic anatomy and has been well-characterised over the past decade. RCTs and longer-term studies are desirable for unbiased comparison of non-standard EVAR modalities.

Abdominal aortic aneurysm neck dilatation and sac remodeling in fenestrated compared to standard endovascular aortic repair

OBJECTIVE

Contemporary commercially available endovascular devices for the treatment of abdominal aortic aneurysm (AAA) include standard endovascular aortic repair (sEVAR) or fenestrated EVAR (fEVAR) endografts. However, aortic neck dilatation (AND) can occur in nearly 25% of patients following EVAR, resulting in loss of proximal seal with risk of aortic rupture. AND has not been well characterized in fEVAR, and direct comparisons studying AND between fEVAR and sEVAR have not been performed. This study aims to analyze AND in the infrarenal and suprarenal aortic segments, including seal zone, and quantify sac regression following fEVAR implantation compared to sEVAR.

METHOD

A retrospective review of prospectively collected data on 20 consecutive fEVAR patients (Cook Zenith® Fenestrated) and 20 sEVAR (Cook Zenith®) patients was performed. Demographic data, anatomic characteristics, procedural details, and clinical outcome were analyzed. Pre-operative, post-operative (1 month), and longest follow-up CT scan at an average of 29.3 months for fEVAR and 29.8 months for sEVAR were analyzed using a dedicated 3D workstation (iNtuition, TeraRecon Inc, Foster City, California). Abdominal aortic aneurysm neck diameter was measured in 5 mm increments, ranging from 20 mm above to 20 mm below the lowest renal artery. Sub-analysis comparing the fEVAR to the sEVAR group at 12 months and at greater than 30 months was performed. Standard statistical analysis was done.

RESULTS

Demographic characteristics did not differ significantly between the two cohorts. The fEVAR group had a larger mean aortic diameter at the lowest renal artery, shorter infrarenal aortic neck length, increased prevalence of nonparallel neck shape, and longer AAA length. On follow-up imaging, the suprarenal aortic segment dilated significantly more at all locations in the fEVAR cohort, whereas the infrarenal aortic neck segment dilated significantly less compared to the sEVAR group. Compared to the sEVAR cohort, the fEVAR patients demonstrated significantly greater positive sac remodeling as evident by more sac diameter regression, and elongation of distance measured from the celiac axis to the most cephalad margin of the sac. Device migration, endoleak occurrence, re-intervention rate, and mortalities were similar in both groups.

CONCLUSION

Compared to sEVAR, patients undergoing fEVAR had greater extent of suprarenal AND, consistent with a more diseased native proximal aorta. However, the infrarenal neck, which is shorter and also more diseased in fEVAR patients, appears more stable in the post-operative period as compared to sEVAR. Moreover, the fEVAR cohort had significantly greater sac shrinkage and improved aortic remodeling. The suprarenal seal zone in fEVAR may result in a previously undescribed increased level of protection against infrarenal neck dilatation. We hypothesize that the resultant decreased endotension conferred by better seal zone may be responsible for a more dramatic sac shrinkage in fEVAR.

Complex Aortic Interventions Can Be Safely Introduced to the Clinical Practice by Physicians Skilled in Basic Endovascular Techniques

Our purpose was to evaluate the risk associated with the learning curve of starting a complex aortic programme in an Eastern European country. A retrospective study was conducted involving the initial 20 patients (16 males, mean age: 65 ± 11 years) undergoing fenestrated/branched endovascular aortic repair in a single centre. Demographic, anatomical, procedural, and postoperative variables were collected. Our elective patient cohort consisted of 9 pararenal aneurysms (45%) and 11 thoracoabdominal aortic aneurysms (55%), with the latter including 4 chronic dissection cases (20%). A total of 71 branch vessels were incorporated (3.5 ± 0.9 per patient). The per vessel technical success rate was 100%. In-hospital mortality was 5% (1/20). At an average follow-up of 14 ± 22 months, the primary clinical success rate was 45% (9/20) and the secondary clinical success was achieved in 75% of cases (15/20). All-cause mortality at 14 months was 20% (4/20; aortic related: 1/20, 5%). Four bridging stent occlusions were found (5.6%). Mortality and reintervention rates were comparable to the initial results of high-volume centres, while the complexity of our cases and the per vessel technical success rate was comparable to the values reported as late experience. The morbidity of the learning curve could be decreased if operators are skilled in basic endovascular procedures.

Fenestrated-branched endovascular repair for distal thoraco-abdominal aortic pathology after total aortic arch replacement with frozen elephant trunk

OBJECTIVE

To report the outcomes of fenestrated-branched endovascular repair (FBEVAR) for thoracoabdominal aortic pathology after total aortic arch replacement with frozen elephant trunk (TAR+FET).

METHODS

Interrogation of prospectively-maintained databases from four high volume aortic centres identified consecutive patients treated with distal FBEVAR after prior TAR+FET between August 2013 and September 2020. Primary endpoint was 30-day/in-hospital mortality. Secondary end points were technical success, early clinical success, mid-term survival and freedom from re-intervention. Data are presented as median (IQR).

RESULTS

39 patients [21 men; median age, 73 years (67-75)] with degenerative (n=22) and post-dissection TAAAs (n=17) [median diameter 71 mm (61-78)] were identified. Distal FBEVAR was intended in 27 patients [median interval 9.8 months (6.2-16.6)], anticipated in seven and unexpected in five. 31 patients had a two (n=24) or three (n=7) stage distal FBEVAR. Reno-visceral target vessel preservation was 99.3% (145 of 146). Early primary and secondary technical success was 92% and 97%, respectively. 30-day mortality was 2.6% [n=1; respiratory failure and spinal cord ischaemia (SCI)]. Six survivors also developed SCI which was associated with complete (n=4), or partial recovery (n=2) at hospital discharge. No patients required renal replacement therapy or suffered a stroke. Early clinical success was 95%. Median follow-up was 30.5 months (23.7-49.7). Eleven patients required 16 late re-interventions. Estimated 3-year survival and freedom from re-intervention were 84±6% and 63±10%, respectively.

CONCLUSIONS

Distal FBEVAR after prior TAR+FET is associated with high technical success and low early mortality. The risk of SCI is significant although the majority of patients demonstrate full or partial recovery before hospital discharge. Mid-term patient survival is favourable but there remains a high requirement for late re-intervention. FBEVAR represents an acceptable alternative to distal open TAAA repair.

Midterm Outcomes of BeGraft Stent Grafts Used as Bridging Stents in Fenestrated Endovascular Aortic Aneurysm Repair

PURPOSE

Fenestrated endovascular aneurysm repair (fEVAR) is established for the treatment of juxtarenal, pararenal, and thoracoabdominal aortic aneurysms (TAAAs). Bridging stents are used to connect the main body of the stent graft to the aortic branch vessels. Complications related to the bridging stents compromise the durability of the repair and require urgent re-intervention. Here we present the midterm results of the BeGraft stent graft system used for fEVAR.

MATERIALS AND METHOD

All consecutive patients treated with fEVAR and the current BeGraft Peripheral Stent Graft between November 2015 and September 2016 were included.

RESULTS

Thirty-nine consecutive patients (38 men) were enrolled and 101 BeGraft second-generation stent grafts were implanted. The median aneurysm diameter was 60 mm (54.5-67.0 mm). Aneurysms were juxtarenal and pararenal (19/39, 48.1%), type 4 TAAA (3/39, 7.7%), type 1, 2, and 3 TAAA (7/39, 17.8%), type 5 TAAA (4/39, 10.2%), and 15.4% (6/39) had a type I endoleak following a previous EVAR. Fifty-five BeGrafts were implanted in mesenteric arteries (22 in coeliac trunks, 31 in the superior mesenteric artery, and 2 in a hepatic or splenic artery) and 46 into renal arteries (24 right and 22 left). The renal artery diameters were 5, 6, 7, and 8 mm in 9, 7, 26, and 4 patients, respectively. Mesenteric arteries were exclusively stented with 9 and 10 mm diameter devices. The median follow-up was 33 months (IQ25 17-IQ75 36). During follow-up, 11 patients died (28%) from non-aneurysm-related causes. The overall patency rates for bridging stents were 98% and 97% at 1 and 2 years, respectively, with a freedom from secondary procedure rate on BeGraft stent grafts of 96% (97/101). All events occurred on stents implanted in renal arteries.

CONCLUSION

Early favorable outcomes are confirmed during longer term follow-up. Vigilant surveillance is required.

An observational assessment of Aortic Deformation During Infrarenal and Complex Endovascular Aortic Aneurysm Repair

OBJECTIVE

Real-time aortic deformation during endovascular aortic aneurysm repair (EVAR) has not been reported. Successful EVAR relies on predicting intraoperative aortic-endograft deformation from preoperative imaging. Correct prediction is essential, as malalignment of endografts decreases patient survival. We describe intraoperative aortic deformation during infrarenal endovascular aneurysm repair (EVAR) and complex fenestrated/branched EVAR (FEVAR/BEVAR), relating deformation to preoperative anatomy and follow-up outcomes.

METHODS

A multicentre retrospective cohort of aortic aneurysm patients undergoing operation January 2019- February 2021, substratified by repair, infrarenal EVAR (n=50), F/BEVAR, (n=80) and iliac branch graft with F/B/EVAR (IBG + F/B/EVAR, n=27), were compared using software-based non-rigid 2D/3D aortic deformational intraoperative assessment (CYDAR). Preoperative CT reconstructions of aortic and iliac tortuosities were assessed against intraoperative deformation, the primary outcome, and related to perioperative/follow-up adverse outcomes.

RESULTS

All treatment groups had low preoperative visceral aortic tortuosity; the EVAR group had higher iliac tortuosity (1.43 +/- .05; p=.018). Intraoperative aortic visceral deformation was consistently cranial and anterior; IBG + F/B/EVAR patients had the largest magnitude deformation (SMA: EVAR 5.1 +/- .9mm; F/BEVAR 4.4 +/- .4mm; IBG 8.3 +/- 1.2mm; p=.004). Celiac, SMA, and bilateral renal deformation was correlated (R=.923-.983). Iliac deformation was variable in magnitude and direction. Preoperative tortuosity was not correlated with the magnitude of intraoperative deformation nor was deformation magnitude related to endograft instability during follow-up, including endoleaks development, reinterventions, or visceral vessel complications.

CONCLUSIONS

The aorta deforms consistently during EVAR at the visceral aortic segment but un-predictably at the iliac bifurcation. Aortoiliac deformation is unrelated to adverse perioperative outcomes, branch instability, or reinterventions during short-term follow-up.

Spinal Cord Ischemia After Thoracoabdominal Aortic Aneurysms Endovascular Repair: From the Italian Multicenter Fenestrated/Branched Endovascular Aneurysm Repair Registry

PURPOSE

The aim of this study is to report an Italian multicenter experience analyzing the incidence and the risk factors associated with spinal cord ischemia (SCI) in a large cohort of thoracoabdominal aortic aneurysms (TAAAs) treated by fenestrated-branched endovascular aneurysm repair (F-/B-EVAR).

MATERIALS AND METHODS

All consecutive patients undergoing F-/B-EVAR in 4 Italian university centers between 2008 and 2019 were prospectively recorded and retrospectively analyzed. Spinal cord ischemia, 30 day/in-hospital adverse events, and mortality were assessed as early outcomes. Risk factors for SCI were determined by multivariable analysis.

RESULTS

A total of 351 patients received F-/B-EVAR for a TAAA. Twenty-eight (8.0%) patients died within 30 postoperative days or during the hospitalization. Regarding SCI, 47 patients (13.4%) developed neurological symptoms related to spinal cord impaired perfusion. Among them, 17 (4.8%) had a major permanent impairment. The multivariable analysis identified that SCI was associated with Crawford extent I to III (odds ratio [OR]: 20.90, p=0.004, 95% confidence interval [CI]=2.69-162.57), and with endovascular procedures performed for ruptured TAAA (OR: 5.74, p=0.010, 95% CI=1.53-21.57). Spinal cord ischemia was also significantly associated with a grade 3 bleeding during the visceral stage (OR: 4.34, p=0.005, 95% CI=1.55-12.16) and a grade 2 renal insufficiency at 30 days (OR: 7.45, p=0.002, 95% CI=2.12-26.18).

CONCLUSION

The present study indicates that SCI is still an open issue after extent I to III TAAA endovascular repair, while its incidence in extent IV TAAA and pararenal/juxtarenal aneurysms is rare. Thoracoabdominal aortic aneurysms extension, urgent TAAA repair for rupture, severe bleeding, and 30 day renal insufficiency have been identified as significant risk factors for SCI. In the presence of such factors, adjunctive strategies may be considered to reduce SCI rates, while in low-risk patients invasive or potentially-risky maneuvers might not be justified.

Iliac Artery Endoconduits Should be the Preferred Adjunctive Access Procedure to Facilitate Complex Endovascular Aortic Aneurysm Repair

BACKGROUND

Iliac artery anatomy can have a dramatic impact on the success of endovascular complex aortic aneurysm (CAA) procedures as endograft delivery systems need to be advanced and manipulated through these access vessels. The aim of this study was to evaluate the outcomes of iliac artery conduits with emphasizes on open vs endovascular conduits performed to facilitate CAA endovascular repair.

METHODS

All patients who had open or endovascular iliac conduits prior to endovascular CAA repair to treat thoracoabdominal, juxtarenal, or suprarenal aneurysms at the University of Colorado Hospital from January 2009 through January 2019 were included. Patients who presented with symptomatic or ruptured aortic aneurysms were excluded. Outcomes of interest included postoperative complications and mortality in patients undergoing iliac conduits.

RESULTS

Twenty-seven patients with a total of 42 conduits were included in the study. The majority of patients (N = 15, 56%) were female and the average age was 72 ± 9 years. The calculated VQI cardiac index was .6% (range, .3%-.8%). Eighteen (43%) endovascular and 24 (57%) open iliac conduits were performed during the study period. Thirty (71%) conduits were performed in a staged fashion, while 12 (29%) were performed at the same time as endovascular CAA repair. The mean time between conduit and definitive aneurysm repair surgery was 130 ± 68 days in the endovascular and 107 ± 79 days in the open groups (P = .87). No aneurysm rupture occurred during the staging period in either group. The median follow-up for the entire cohort was 18 ± 22 months. The median length of hospital stay for patients undergoing endovascular and open ICs was 6 (ranging, 1-28 days) and 7 days (ranging, 3-18 days), respectively. Patients undergoing open conduits had significantly more complications than those undergoing endovascular conduit (endoconduit) creation. A total of 4 (15%) patients died within 30 days after aneurysm repair. Out of 23 survivors, 18 (78%) patients were discharged home, 4 (18%) patients were discharged to a skilled nursing facility, and 1 (4%) patient was discharged to an acute rehabilitation facility. No mortality difference based on type of conduit was found.

CONCLUSIONS

Overall complication rate associated with creation of open iliac artery conduits is not negligible. Endoconduits, which carry less morbidity than open conduits, are preferred as a first-line adjunctive access procedure to facilitate complex endovascular aortic aneurysm repair.

Rescue of Failed Aortic Repair with Fenestrated Endovascular Device

INTRODUCTION

The incidence of failed endovascular (EVAR) and open repair (OR) is increasing. Redo aortic repair is required in 10% of patients. Extension of the proximal sealing zone above the visceral arteries to adequate, healthier thoracic aorta using a fenestrated graft (FEVAR) can rescue a failing repair. A custom-made device can treat proximal type 1A endoleaks or proximal dilatation post endovascular or open repair, respectively. The aim of this investigation was to present a single-centre experience with FEVAR for patients with a failing aortic repair.

METHODS

A prospectively maintained database of FEVAR patients treated with a Zenithࣨ Fenestrated endovascular (ZFEN) device (Cook Medical LLC, Bloomington, Indiana, USA) was interrogated for individuals who had the device implanted as a rescue therapy after prior endovascular (EVAR) or open repair (OR). Statistical analysis was performed with SPSS v 25 software.

RESULTS

Between January 1, 2011 and March 31, 2019, 17 ZFEN devices were implanted. Ten patients had a type 1A endoleak from a prior EVAR and seven patients had proximal disease progression after prior OR. There were 12 males and 5 females, median age of 75 (interquartile range, IQR 7). 76.4% (n=13) of patients had an American Society of Anaesthesiologists (ASA) grade of 3. Primary technical success was 70.5% (n=12). Of the remainder, four cases (24%) had a type III endoleak at completion angiogram; of which, two patients (12%) required re-intervention within 30 days. One further case (6%) had primary assisted technical success as stenting of a flow limiting dissection flap in an iliac vessel was required. Peri-operative rate of deployment related complications and systemic complications were 5.8% (n=1) and 35% (n=6), respectively. Median length of hospital stay was 11 days (IQR 11). There was no mortality within the study follow up. Overall thirty-day re-intervention rate was 23.5%. Overall survival was 92% at one year.

CONCLUSION

FEVAR is a safe but technically challenging option for rescue of failing aortic repairs. These are a high risk group of patients and this is reflected in the high post-operative morbidity rate. Technical success was high and 30-day mortality was low.

Long-term Outcomes after FEVAR for Juxtarenal Aortic Aneurysm

OBJECTIVE

Fenestrated endovascular aortic repair (FEVAR) for juxtarenal aortic aneurysm (jAAA) disease is safe and effective with good short- and mid-term outcomes. Durability issues focus mainly on proximal and distal seal as well as target vessel (TV) instability, and long-term data is scarce. In previous publications we have reported short-term outcomes after FEVAR while comparing early- and late-experience patient groups, as well as long-term results for the early cohort. In this series we provide long-term outcome in the late experience cohort treated with FEVAR in Vascular Center Malmö.

METHODS

Consecutive patients treated in Vascular Center Malmö with FEVAR for jAAA between 2007 and 2011 were included. Data was collected retrospectively from medical- and imaging records. Follow up consisted of a clinical examination 1 month post-operatively, and computed tomography angiography combined with plain abdominal X-ray at 1 and 12 months, and annually thereafter. Primary endpoints were TV instability, reinterventions and survival. Changes in aneurysm diameter and renal function as well as endoleaks were also analyzed.

RESULTS

94 patients were treated. Median follow-up time was 89 (range 0-152) months. 280 fenestrations or scallops were employed of which 205 were stented. Technical success was 89.4%. Primary TV patency was 94% ± 1 % at 1year, 90% ± 2% at 3 years and 89% ± 2% at 5 years. 37 (39.4%) patients needed a total of 70 reinterventions and mean time to first reintervention was 21 ± 3.97 months. 5 (5.3%) patients died of aneurysm related causes and overall survival was 95.7% ± 2.1% at 1 year, 87.1% ± 3.5% at 3 years and 71.0 ± 4.7% at 5 years. A stable or decreasing aortic diameter after treatment was seen in 91% of cases. Mean glomerular filtration rate (GFR) fell from 59.2 ± 14.9 ml/min/1.73m² pre-operatively to 50.0 ± 18.6 ml/min/1.73 m² at end of follow-up.

CONCLUSION

Long-term results after treatment of jAAA with FEVAR remain good and the treatment is safe and effective. Although the need for reintervention remains high, long-term renal function and survival support the use of FEVAR as a valid treatment option for jAAA disease.

Intracranial Hemorrhage After Endovascular Repair of Thoracoabdominal Aortic Aneurysm

BACKGROUND

Intracranial hemorrhage (ICH) is a rare but devastating complication of thoracoabdominal aortic aneurysm (TAAA) repair with fenestrated/branched endograft (f/bEVAR). The cerebrospinal fluid drainage (CSFD) is considered one of the leading causes; however, other possible concomitant factors have not been individualized yet. The aim of the present work was to evaluate the pattern of ICH events after f/bEVAR for TAAA and to identify possible associated factors.

MATERIALS AND METHODS

All f/bEVAR procedures for TAAA performed in a single academic center from 2012 to 2020 were evaluated. ICH was assessed by cerebral computed tomography if neurological symptoms arose. Pre-, intra-, and postoperative characteristics were analyzed in order to identify possible factors associated.

RESULTS

A total of 135 f/bEVAR were performed for 72 (53%) type I, II, III and 63 (47%) type IV TAAA; 74 (55%) were staged procedures, 101 (73%) required CSFD, and 24 (18%) were performed urgently. The overall 30-day mortality was 8% (5% in elective cases); spinal-cord ischemia occurred in 11(8%) and ICH in 8 (6%) patients. All ICH occurred in patients with CSFD. ICH occurred intraoperatively in 1 case, inter-stage in 4 and after F/BEVAR completion in 3, after a median of 6 days the completion stage. Three (38%) of 8 patients with ICH died at 30 days and ICH was associated with 30-day mortality: odds ratio (OR) 13.2, 95% confidence interval (CI): 2.3-76, p=0.01. The analysis of the perioperative characteristics identified platelet reduction >60% (OR 11, 95% CI 1.6-77, p=0.03), chronic kidney disease (16% vs 0%, p=0.002), and total volume of liquor drained >50 mL (OR 8.1, 95% CI 1.1-69, p=0.03) as associated with ICH.

CONCLUSIONS

Current findings may suggest that ICH is a potential lethal complication of the endovascular treatment for TAAAs and it mainly occurs in patients with CSFD. High-volume liquor drainage, platelet reduction, and chronic kidney disease seems increase significantly the risk of ICH and should be considered during the perioperative period and for further studies.

Systematic review with pooled data analysis reveals the need for a standardized reporting protocol including the visceral vessels during fenestrated endovascular aortic repair (FEVAR)

OBJECTIVES

To collect and analyse the available evidence in the outcomes of patients treated with fenestrated endovascular aortic repair (f-EVAR) technique focusing specifically on visceral vessel outcomes.

METHODS

The current meta-analysis was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. All the studies reporting the f-EVAR technique for the management of degenerative pararenal and/or type IV thoracoabdominal aortic aneurysms (TAAA) were considered eligible for inclusion in the study. The main study outcomes (technical success, type I endoleaks, fracture or occlusion of the bridging stents, overall aneurysm-related mortality, and the reintervention rate) were subsequently expressed as proportions and 95% confidence intervals.

RESULTS

Fourteen studies with a total of 1804 patients were included in a pooled analysis. The technical success of the procedure was 95.97% (95%CI = 92.35-98.60). Intraoperatively, the pooled proportion of reported type I endoleak was 7.6% (95%CI = 2.52-14.60) while during a median follow-up of 41 months (range 11-96) follow-up period the pooled rate of fracture and occlusion of the bridging stents was 2.79% (95%CI = 0.00-8.52) and 4.46% (95%CI = 1.93-7.77), respectively. The overall aneurysm-related mortality was detected to be 0.63% (95%CI = 0.04-1.63), and the pooled estimate for re-intervention rate was 15.69%.

CONCLUSIONS

Fenestrated endovascular repair for p-AAA is an effective and safe treatment. Target vessel complications and endoleaks remain the two most important concerns for fenestrated endovascular procedures, contributing to most of the secondary interventions. The lack of computed tomography angiography follow-up evaluation does not allow us to draw robust conclusions about the complication rates for the superior mesenteric artery during f-EVAR. Due to the potential implications of SMA complications on aneurysm-related mortality, standardized reporting of short- and long-term target visceral vessel outcomes is required.

Characterising the incidence and mode of visceral stent failure after fenestrated endovascular aneurysm repair (FEVAR)

Background

In FEVAR, visceral stents provide continuity and maintain perfusion between the main body of the stent and the respective visceral artery. The aim of this study was to characterise the incidence and mode of visceral stent failure (type Ic endoleak, type IIIa endoleak, stenosis/kink, fracture, crush and occlusion) after FEVAR in a large cohort of patients at a high-volume centre.

Methods

A retrospective review of visceral stents placed during FEVAR over 15 years (February 2003-December 2018) was performed. Kaplan-Meier analyses of freedom from visceral stent-related complications were performed. The outcomes between graft configurations of varying complexity were compared, as were the outcomes of different stent types and different visceral vessels.

Results

Visceral stent complications occurred in 47/236 patients (19.9%) and 54/653 stents (8.3%). Median follow up was 3.7 years (IQR 1.7–5.3 years). There was no difference in visceral stent complication rate between renal, SMA and coeliac arteries. Visceral stent complications were more frequent in more complex grafts compared to less complex grafts. Visceral stent complications were more frequent in uncovered stents compared to covered stents. Visceral stent-related endoleaks (type Ic and type IIIa) occurred exclusively around renal artery stents. The most common modes of failure with SMA stents were kinking and fracture, whereas with coeliac artery stents it was external crush.

Conclusion

Visceral stent complications after FEVAR are common and merit continued and close long-term surveillance. The mode of visceral stent failure varies across the vessels in which the stents are located.

Fenestrated Pedicle Screws in Spinal Oncology: Technique and Comparative Retrospective Analysis

BACKGROUND

The use of spinal stabilization with decompression has been shown to improve survival, spinal stability, and ambulatory status in patients with metastatic spinal tumors. However, the poor bone quality typically seen in these patients can prevent adequate stabilization. Fenestrated pedicle screws permit augmented fixation via injection of bone cement into the vertebral body upon screw placement, potentially mitigating the difficulties in achieving adequate stabilization in these patients.

OBJECTIVE

To compare surgical outcomes of posterior spinal fusion in patients with cancerous spinal lesions between polymethyl methacrylate cement-augmented fenestrated screws and standard pedicle screws.

METHODS

A total of 19 consecutive patients with cancerous spinal lesions receiving posterior spinal fusion (PSF) with pedicle screws from a single surgeon were retrospectively reviewed for demographic information, comorbidities, surgical parameters, and outcomes.

RESULTS

Ten patients underwent PSF with cement augmentation, whereas 9 underwent standard PSF. There was no significant difference in demographics, comorbidities, or surgical characteristics. Operative time was significantly greater in the cement-augmented group (302 ± 100 minutes vs 203 ± 55 minutes; P = .015). There was no significant difference in rates of operation or readmission between the cohorts nor was there any significant difference in discharge disposition. There was 1 case of surgical site infection (in a patient with a fenestrated screw) and no cases of cement extravasation. No instances of mechanical hardware failure were recorded.

CONCLUSIONS

Fenestrated screws confer similar risk profiles as nonfenestrated screws for posterior spinal fusion in patients with spinal cancer. However, fenestrated screws may affect operative time, radiation exposure, and impose risk of cement extravasation. Cement-augmented fenestrated pedicle screws may be a viable option for patients with poor bone quality associated with metastatic disease without significantly increased rates of surgical complications.

LEVEL OF EVIDENCE

3.

Surgeon-modified fenestrated stent graft deployment in type B aortic dissection

The treatment of aortic dissections and aneurysms may be challenging for vascular surgeons. Currently, thoracic endovascular aortic repair is usually the first treatment option for descending aortic pathologies. Left subclavian artery coverage during this procedure is often required to achieve a sufficient proximal landing zone. Most surgeons agree that the left subclavian artery can be selectively covered, but revascularization is preferred to reduce the risk of neurological or ischemic complications. The chimney method, hybrid operations with extra-anatomic bypass, back table or in situ fenestrations are assistive techniques in this procedure. Herein, we present a surgeon-modified fenestrated stent graft for a type B aortic dissection patient.

Comparison of Fluid Dynamics Variations Between Chimney and Fenestrated Endografts for Pararenal Aneurysms Repair: A Patient Specific Computational Study as Motivation for Clinical Decision-Making

BACKGROUND-AIM

Limited data exist concerning the fluid dynamic changes induced by endovascular aortic repair with fenestrated and chimney graft modalities in pararenal aneurysms. We aimed to investigate and compare the wall shear stress (WSS) and flow dynamics for the branch vessels before and after endovascular aortic repair with fenestrated and chimney techniques.

METHODS

Modeling was done for patient specific pararenal aortic aneurysms employing fenestrated and chimney grafts (Materialise Mimics 10.0) before and after the endovascular procedure, using computed tomography scans of patients. Surface and spatial grids were created using the ANSYS CFD meshing software 2019 R2. Assessment of blood flow, streamlines, and WSS before and after aneurysm repair was performed.

RESULTS

The endovascular repair with chimney grafts leaded to a 43% to 53% reduction in perfusion in renal arteries. In fenestrated reconstruction, we observed a 15% reduced perfusion in both renal arteries. In both cases, we observed a decrease in the recirculation phenomena of the aorta after endovascular repair. Concerning the grafts of the renal arteries, we observed in both the transverse and longitudinal axes low WSS regions with simultaneous recirculation of the flow 1 cm distal to the ostium sites in both aortic graft models. High WSS regions appeared in the sites of ostium.

CONCLUSIONS

We observed reduced renal perfusion in chimney grafts compared to fenestrated grafts, probably caused by the long and kinked characteristics of these devices.

Advanced endografting techniques: snorkels, chimneys, periscopes, fenestrations, and branched endografts

The anatomy of aortic aneurysms from the proximal neck to the access vessels may create technical challenges for endovascular repair. Upwards of 30% of patients with abdominal aortic aneurysms (AAA) have unsuitable proximal neck morphology for endovascular repair. Anatomies considered unsuitable for conventional infrarenal stent grafting include short or absent necks, angulated necks, conical necks, or large necks exceeding size availability for current stent grafts. A number of advanced endovascular techniques and devices have been developed to circumvent these challenges, each with unique advantages and disadvantages. These include snorkeling procedures such as chimneys, periscopes, and sandwich techniques; "homemade" or "back-table" fenestrated endografts as well as manufactured, customized fenestrated endografts; and more recently, physician modified branched devices. Furthermore, new devices in the pipeline under investigation, such as "off-the-shelf" fenestrated stent grafts, branched stent grafts, lower profile devices, and novel sealing designs, have the potential of solving many of the aforementioned problems. The treatment of aortic aneurysms continues to evolve, further expanding the population of patients that can be treated with an endovascular approach. As the technology grows so do the number of challenging aortic anatomies that endovascular specialists take on, further pushing the envelope in the arena of aortic repair.

Treatment for thoracoabdominal aortic aneurysm by fenestrated endovascular aortic repair with physician-modified stent graft

Despite being widely used for several years, the endovascular aortic repair (EVAR) of a thoracoabdominal aneurysm (TAAA) remains challenging, particularly the revascularization of the abdominal aortic visceral branches. A 66-year-old male was admitted to hospital with abdominal bloating and pain. Computed tomographic angiography (CTA) confirmed a Crawford type III TAAA from the distal descending aorta to the suprarenal abdominal aorta that involved the celiac axis, accompanied with an occlusion of the left subclavian artery. Fenestrated-EVAR was performed successfully and 1 week later CTA showed a type III endoleak, which had resolved 3 months later, without stent migration or visceral artery occlusion. In this present case, the surgeons preferred to perform the procedure in three surgical stages, postponing the deployment of a covered stent in the CA fenestration to provide additional time for the development of collateral circulation to the spinal cord as a possible means of preventing postoperative paraplegia.

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.

Update on the use of abdominal and thoracic endografts for treating aortic aneurysms

Endovascular abdominal and thoracic aneurysm repair has heralded a paradigm shift in the management of abdominal and thoracic aortic aneurysms. Randomized controlled trials have suggested superior short-term and equivalent long-term outcomes of endovascular repair compared with open surgery. Existing endografts have undergone several modifications to meet anatomic challenges and improve patient results. In the past, endovascular repair has been limited to infrarenal abdominal aortic aneurysms and isolated thoracic aortic aneurysms. The advent of fenestrated and branched endografts have made endovascular repair of thoracoabdominal and juxtarenal aneurysms possible. Continued evolution of endograft technology will maximize the benefit and minimize complications in patients with a range of aneurysmal disease.

The Current State of Fenestrated and Branched Devices for Abdominal Aortic Aneurysm Repair

Endovascular abdominal aortic aneurysm repair (EVAR) provides an attractive alternative to traditional open techniques. Endovascular repair is frequently limited by aortic aneurysm neck angulation, the absence of an adequate infrarenal neck, and the need for internal iliac preservation. Several devices have been created to incorporate visceral artery segments as well as preserve the internal iliac artery, thus broadening the patient population suited for endovascular repair. This article will provide a review of the current literature regarding fenestrated devices, branch devices, off-the-shelf devices, and physician-modified devices. It will also highlight the iliac branch stent grafts currently on trial for internal iliac artery preservation. Data thus far have suggested that these devices will be both a safe and effective option for anatomically challenging abdominal aortic aneurysms.

The shear stess profile of the pivotal fenestrated endograft at the level of the renal branches: A computational study for complex aortic aneurysms

PURPOSE

This study investigated the impact of the variant angulations on the values and distribution of wall shear stress on the renal branches and the mating vessels of a pivotal fenestrated design.

METHODS

An idealized endograft model of two renal branches was computationally reconstructed with variable angulations of the left renal branch. These ranged from the 1:30' to 3:30' o'clock position, corresponding from 45° to 105° with increments of 15°. A fluid-structure-interaction analysis was performed to estimate the wall shear stress.

RESULTS

The proximal part of the renal branch preserved quite constant wall shear stress. The transition zone between its distal end and the renal artery showed the highest values compared to the proximal and middle segments, ranging from 8.9 to 12.4 Pa. The lowest stress values presented at 90° whereas the highest at 45°. The post-mating arterial segment showed constantly low stress values regardless of the pivotal branch angle (6.3 to 6.6 Pa). The 45° configuration showed a distribution of the highest stress posteriorly whereas the 105°-angulation anteriorly.

CONCLUSIONS

The variant horizontal branch orientation influences the wall shear stress distribution across its length and affects its values only at its transition with the mating vessel. These findings and their potential association with adverse effects deserve further clinical validation.

Endovascular management of chronic post-dissection aneurysms

Open repair is still the gold standard in acute type A dissection. Endovascular repair is advocated for complicated acute type B dissections. Recent evidence also supports the role of endovascular repair in a larger proportion of uncomplicated acute type B dissections. The role of endovascular repair in chronic post-dissection aneurysms, however, is still unclear. Most commonly, post-dissection aneurysms involve the thoracoabdominal aorta, making the use of fenestrated/branched stent-grafts to achieve complete aneurysm exclusion mandatory. These fenestrated/branched stent-grafts have been used with success in atherosclerotic thoracoabdominal aortic aneurysms (TAAAs). In chronic post-dissection aneurysms, however, additional technical challenges arise. The usually narrow true lumen makes the use of branches more tedious and overall planning difficult. A second technical challenge relates to the fact that visceral branches can also originate from the false lumen. In such cases, perforation of the stiff chronic dissection flap is required to obtain access to the vessel. During the period January 2010 to November 2013, 17 patients (13 males, mean age 65±7.8 years) with chronic thoracoabdominal aneurismal degeneration following acute dissection were treated in our department with the use of fenestrated/branched stent-grafts. Technical success was achieved in all cases (100%). Perioperative mortality was two (11.8%) patients. One patient died due to multiple organ failure and one due to cardiac failure. No case of paraplegia was observed. During a 12-month median follow-up (range, 4-28 months) no aneurysm-related deaths were observed. Reintervention was required in three cases to repair a type Ib endoleak from a side branch. Endovascular treatment with fenestrated/branched stent-grafts is feasible for chronic post-dissection aneurysms. Standard thoracic stent-grafting is an option in a minority of patients, when the aneurysm is limited to the thoracic segment. Fenestrated and branched devices can successfully be used for aneurysms extending to the thoracoabdominal aorta.

Technique of implantation and bail-out maneuvers for endovascular fenestrated repair of juxtarenal aortic aneurysms

Endovascular repair of complex aneurysms involving the visceral arteries has become a reality. Fenestrated endovascular aortic repair (FEVAR) has been used with increasing frequency to treat complex aortic aneurysms. The Zenith fenestrated stent-graft system (Cook Medical Inc, Brisbane, Australia) was approved for commercial use in the United States in April 2012, offering a custom-made design with up to 3 fenestrations to treat short-neck infrarenal and juxtarenal abdominal aortic aneurysms. Nevertheless, FEVAR is a complex procedure that demands accurate planning, advanced endovascular skills, and excellent perioperative patient care to achieve optimal outcomes. This article summarizes the basic concepts of device design, case planning, techniques of implantation, and some of the "bail-out" maneuvers that may be required during endovascular repair using the Zenith fenestrated stent-graft system.