Outcomes of Fenestrated Endografts in the Treatment of Abdominal Aortic Aneurysm in Western Australia (1997–2004)

Mid-term Outcomes of the Viabahn VBX® Balloon-Expandable Covered Stent for Fenestrations During Complex Endovascular Aortic Aneurysm Repair (EVAR)

OBJECTIVES

The optimal bridging stent for fenestrations during complex endovascular aortic aneurysm repair (EVAR) has not been defined. At our institution, the Viabahn VBX® is frequently used given its availability and mechanical and heparin-bonding characteristics. This study aims to assess the performance of the Viabahn VBX® versus the iCast® balloon-expandable covered stents as bridging stents for fenestrations during complex EVAR.

METHODS

A retrospective study of consecutive patients undergoing complex EVAR between 2015 and 2021 was performed. Celiac arteries (CAs), superior mesenteric arteries (SMAs), left renal arteries (LRAs), and right renal arteries (RRAs) stented with fenestrations were grouped according to the type of bridging stent, VBX® versus iCast®. Target vessels (TV) stented with a branch or scallop were excluded. The primary endpoints included primary patency and freedom from target vessel instability (TVI).

RESULTS

A total of 292 patients undergoing complex EVAR were treated using VBX® or iCast® with a mean follow-up of 190 days (interquartile range [IQR], 36-384) for the VBX® cohort and 804 days (IQR, 384-1507) for the iCast® cohort. A total of 677 TVs were stented, including 134 (20%) CAs, 175 (26%) SMAs, 182 (27%) LRAs, 186 (27%) RRAs, and 12 (2%) additional vessels. Proximal reinforcement was more frequent with VBX than with iCast® stent (23% vs. 2.4%, P <.0001). There was no difference in primary patency rates at 2-year between VBX® and iCast® stent for CA (100% vs. 96.4%; P=.32), SMA (97.8% vs. 100%; P=.14) and renal arteries (96.7% vs. 99.4%; P=.11). There was no difference between VBX® and iCast® in the cumulative incidence of type Ic and type IIIc endoleaks (3.2% vs. 5.6%; P=.69) or freedom from TVI at 2 years.

CONCLUSION

Viabahn VBX® stents are a safe and effective option as bridging stents in fenestrations during complex EVAR with comparable mid-term outcomes to iCast® stents. However, proximal stent reinforcement may be required with VBX stent to ensure adequate sealing at the fenestrations. Longer follow-ups and larger series are required to assess long-term outcomes and durability.

Fenestrated and branched endovascular repair for juxtarenal and thoracoabdominal aortic aneurysms: analysis of the first 100 cases

BACKGROUND

Endovascular aortic aneurysm repair (EVAR) has become the most popular technique to treat infrarenal abdominal aortic aneurysms. In aneurysms with unsuitable anatomy open surgical repair remains the golden standard but fenestrated EVAR (FEVAR) or branched EVAR (BEVAR) may be an alternative to treat juxtarenal or thoracoabdominal aneurysms. The aim of this study was to report our results and to evaluate its safety and feasibility.

METHODS

This is a single center cohort study analyzing all consecutive patients undergoing FEVAR or BEVAR.

RESULTS

One hundred patients underwent a procedure between June 2012 and December 2019. Forty-seven percent had a history of coronary artery disease and 31% of previous aortic repair. Sixty percent were treated for a juxtarenal and 40% for a TAAA. Primary technical success was 87%. Overall, thirty-day mortality was 6%, with 50% of the deaths resulting from a myocardial infarction. Four percent had a bowel resection for ischemia, 3% developed a stroke and 3% spinal cord ischemia. Mean follow-up was 33.6±22.4 months, freedom from all-cause mortality was 89.3±3.2% at one year and 66.4±7.6% at five years. Six intraoperative target vessel events were noted (1.7%), six early postoperative (1.7%) and three late (0.8%). A total of ten (10%) late procedure related secondary interventions were performed, among which six for endoleak.

CONCLUSIONS

This study confirms that fenestrated and branched endovascular repair is a safe and feasible treatment for juxtarenal and thoracoabdominal aortic aneurysms with acceptable complication rates. The perioperative cardiac mortality highlights the importance of preoperative risk assessment and patient selection.

Open versus Endovascular Abdominal Aortic Aneurysm Repair in the Australian Private Sector Over Twenty Years

PURPOSE

Over the past two decades, the proliferation of endovascular surgery has changed the approach to abdominal aortic aneurysm (AAA) repair. In Australia, close to two-thirds of surgical procedures are performed in the private healthcare system. We aimed to describe the trends in AAA repair in the Australian private sector throughout the early 21st century.

MATERIALS AND METHODS

Medicare Benefits Schedule (MBS) statistics were accessed to determine the number of infrarenal open AAA repair (OAR) and endovascular AAA repair (EVAR) procedures performed between January 2000 and December 2019. Population data were extracted from the Australian Bureau of Statistics and used to calculate incidence per 100,000 population. Further analysis was performed according to age, gender, and state.

RESULTS

During the study period, 13,193 (67.0%) EVARs and 6504 (33.0%) OARs were performed in the Australian private sector. OARs fell from 70.5% (n=567) of AAA repairs in 2000 to 15.7% (n=237) in 2019, while EVARs rose from 29.5% (n=151) to 84.3% (n=808). The frequency of EVAR surpassed OAR in 2004. The overall incidence of AAA repair varied minimally over the time period (range: 4.9-6.5 per 100,000 adults per year). AAA repair was more common in males than females (9.7 vs 1.7 per 100,000 population) and more common in older age groups. There was a 4-fold increase in EVAR among males older than 85 years (12.8-57.4 per 100,000 population), the largest rise of any group. The overall EVAR:OAR ratio increased from 0.4 to 5.4. There were considerable state-based discrepancies.

CONCLUSION

The landscape of AAA repair in Australian private sector has drastically changed with a clear preference toward EVAR. EVAR saw increased use across all genders, age groups and states, despite stable rates of AAA surgery. Further research is necessary to compare our findings to national trends in the Australian public sector.

Ceiling Technique to Facilitate Target Vessel Catheterization During Complex Aortic Repair

Aim of this paper is to describe a simple and helpful technique for challenging visceral vessel catheterization during complex aortic endovascular procedures. In demanding anatomies when standard visceral vessel cannulation maneuvers result ineffective, inflating a compliant balloon above the target arteries may allow easy and safe advancement of the introducer sheath inside selected vessel. This approach lowers the shear forces enhancing device pushability. The use of a compliant aortic balloon with the Ceiling technique is a useful, easy and reproducible endovascular option that can be adopted for challenging vessel catheterization during advanced endovascular procedures.

The Italian Multicentre Registry of Fenestrated Anaconda™ Endografts for Complex Abdominal Aortic Aneurysms Repair

OBJECTIVE

The aim was to describe the outcomes of the Anaconda™ Fenestrated endograft Italian Registry for complex aortic aneurysms (AAAs), unsuitable for standard endovascular aneurysm repair (EVAR).

METHODS

Between 2012 and 2018 patients with a proximal neck unsuitable for standard EVAR, treated with the fenestrated Anaconda™ endograft, were prospectively enrolled in a dedicated database. Endpoints were peri-operative technical success (TS) and evaluation of type Ia/b or 3 endoleaks (T1/3 EL), target visceral vessel (TVV) occlusion, re-interventions, and AAA related mortality at 30 days, six months, and later follow up.

RESULTS

One hundred twenty seven patients (74 ± 7 years, American Society Anesthesiology (ASA) II/III/IV: 12/85/30) were included in the study in 49 Italian Vascular Surgery Units (83 juxta/para-renal AAA, 13 type IV thoraco-abdominal AAA, 16 T1aEL post EVAR, and 15 short neck AAA). Configurations with one, two, three, and four fenestrations were used in 5, 56, 39, and 27 cases, respectively, for a total of 342 visceral vessels. One hundred and eight (85%) bifurcated and 19 (15%) tube endografts were implanted. In 35% (44/127) of cases the endograft was repositioned during the procedure, and 37% (128/342) of TVV were cannulated from brachial access. TS was 87% (111/127): five T1EL, six T3EL (between fenestration and vessel stent), and six loss of visceral vessels (one patient with a Type Ia EL had also a TVV loss) occurred. Thirty day mortality was 4% (5/127). Two of the five T1EL resolved spontaneously at 30 days. The overall median follow up was 21 ± 16 months; one T1EL (5%) occurred at six months and one T3EL (4%) at the three year follow up. Another two (3%) TVV occlusions occurred at six months and five (3%) at three years. The re-intervention rate at the 30 days, six months, and three year follow up was 5%, 7%, and 18 ± 5%, respectively.

CONCLUSION

The fenestrated Anaconda™ endograft is effective in the treatment of complex AAA. Some structure properties, such as the re-positionability and the possibility of cannulation from above, are specific characteristics helpful for the treatment of some complex anatomies.

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.

Cross-clamp location affects short-term survival in patients undergoing open abdominal aortic aneurysm repair

INTRODUCTION

Open abdominal aortic aneurysm (oAAA) repair in the era of advanced endovascular aortic techniques is used in challenging anatomy. The impact of the location of the proximal aortic cross-clamp (suprarenal [SR] vs infrarenal [IR]) on outcomes remains to be determined. The aim of this study was to analyze the effect of proximal aortic cross-clamp location on short-term and overall survival after oAAA repair in a contemporary series.

METHODS

A retrospective cohort study was performed comparing the outcomes of patients undergoing oAAA repair with SR and IR aortic cross-clamping using the Vascular Quality Initiative registry from January 2003 to September 2018. Our primary end point was short-term mortality.

RESULTS

There were 7601 patients who underwent oAAA repair. Their mean age was 69.3 ± 8.5 years and 5555 patients (73.1%) were male. The aortic cross-clamp location was IR in 4044 patients (53.2%). The SR group had increased maximum AAA diameter (58 mm vs 56 mm; P < .0001), hypertension (85.5% vs 82.0%; P < .0001), preoperative creatinine (1.11 vs 1.08; P = .001), and were more likely to be in American Society of Anesthesiologists class IV (37.4% vs 30.6%; P < .0001). Postoperative renal failure occurred significantly more often in the SR group (24.4 vs 11.4%; P < .0001). Short-term mortality was 2.7% in the IR group and 4.7% in the SR group (P < .0001). Kaplan-Meier survival estimates were 93.7% and 83.8% in the IR group and 90.9% and 81.2% in the SR group at 1 and 5 years, respectively (P = .007). Multivariable analysis demonstrated that SR cross-clamping was significantly associated with short-term mortality (hazard ratio, 1.38; 95% confidence interval, 1.07-1.78; P = .01); however, it did not affect overall survival (hazard ratio, 1.13; 95% confidence interval, 1.00-1.28; P = .06).

CONCLUSIONS

A SR cross-clamp location is associated with an increased short-term mortality in patients undergoing oAAA repair. Overall survival is not affected by a SR cross-clamp location.

Hemodynamic Performance of Multilayer Stents in the Treatment of Aneurysms with a Branch Attached

Although multilayer stents (MSs) can be used to treat aneurysm effectively, for some aneurysms with branches attached, the hemodynamic mechanisms are still unclear. In this work, we modeled five cases that involve 1-4-layer stents implanted in aneurysms with side branches, and the numerical approach was used. Case 1 corresponds to an aneurysm without a stent, and cases 2-5 represent 1-4-layer stents being employed within aneurysms, respectively. The results showed that the velocity within the sac declined dramatically and the eddies' intensity weakened with increased number of stent layers, time-averaged wall shear stress (TAWSS), and nitric oxide production rate (TARNO) dropped linearly with increase in stent porosity, and oscillatory shear index (OSI) and relative residence time (RRT) increased evidently with MS intervention. Moreover, the MSs had a slight effect on the patency of the side branch; its flow rate was still above the normal case than without aneurysm. It can be concluded that MSs are helpful in promoting the growth of thrombus within the aneurysm through an isolated hemodynamic environment and keeping the branch unobstructed, but more clinical evidences are required.

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.

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.

National trends in open surgical, endovascular, and branched-fenestrated endovascular aortic aneurysm repair in Medicare patients

BACKGROUND

Open repair effectively prevents rupture for patients with abdominal aortic aneurysm (AAA) and is commonly studied as a metric reflecting hospital and surgeon expertise in cardiovascular care. However, given recent advances in endovascular aneurysm repair (EVAR), such as branched-fenestrated EVAR, it is unknown how commonly open surgical repair is still used in everyday practice.

METHODS

We analyzed trends in open AAA repair, EVAR, and branched-fenestrated EVAR for AAA in Medicare beneficiaries from 2003 to 2013. We used Medicare Part B claims to ascertain counts of these repair types annually during the study period. We assessed regional and national trends in characteristics of the patients and procedure volume.

RESULTS

Between 2003 and 2013, the total number of AAA repairs performed in fee-for-service Medicare patients declined by 26% from 31,582 to 23,421 (P < .001), after a peak number of 32,540 was performed in 2005 (28% decline since 2005). The number of open AAA repairs steadily declined by a total of 76%, from 20,533 in 2003 to 4916 in 2013 (P < .001). Whereas the number of EVARs increased from 11,049 in 2003 to 19,247 in 2011 (P < .001), it has since declined a total of 15% to only 16,362 repairs in 2013 (P < .001). After its introduction in 2011, the number of branched-fenestrated EVAR cases continuously rose from 335 procedures in 2011 to 2143 procedures in 2013 (P < .001). By 2013, virtually all hospital referral regions in the United States had rates of open AAA repair that would have been in the lowest quintile of volume in 2003.

CONCLUSIONS

The number of open AAA repairs fell by nearly 80% during the last decade, whereas traditional EVAR declined slightly and branched-fenestrated EVAR rapidly disseminated into national practice. These results suggest that open AAA repair is now performed too infrequently to be used as a metric in the assessment of hospital and surgeon quality in cardiovascular care. Furthermore, surgical training paradigms will need to reflect the changing dynamics necessary to ensure that surgeons and interventionists can safely perform these high-risk surgical procedures.

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.

Editor's Choice - Comparison of Renal Outcomes in Patients Treated by Zenith® Fenestrated and Zenith® Abdominal Aortic Aneurysm Stent grafts in US Prospective Pivotal Trials

OBJECTIVE/BACKGROUND

Fenestrated endovascular repair (FEVAR) has been used to treat complex abdominal aortic aneurysms (AAAs). The risk of renal function deterioration compared with infrarenal endovascular aortic repair (EVAR) has not been determined.

METHODS

Patients with preserved renal function (estimated glomerular filtration rate [eGFR] > 45 mL/minute) enrolled in two prospective, non-randomised studies evaluating Zenith fenestrated and AAA stent grafts were matched (1:2) by propensity scores for age, sex, hypertension, diabetes, and pre-operative eGFR. Sixty-seven patients were treated by FEVAR and 134 matched controls treated by EVAR. Mean follow-up was 30 ± 20 months. Outcomes included acute kidney injury (AKI) defined by RIFLE and changes in serum creatinine (sCr), eGFR, and chronic kidney disease (CKD) staging up to 5 years.

RESULTS

AKI at 1 month was similar between groups, with > 25% decline in eGFR observed in 5% of FEVAR and 9% of EVAR patients (p = .39). There were no significant differences in > 25% decline in eGFR at 2 years (FEVAR 20% vs. EVAR 20%; p > .99) or 5 years (FEVAR 27% vs. EVAR 50%; p = .50). Progression to stage IV-V CKD was similar at 2 years (FEVAR 2% vs. EVAR 3%; p > .99) and 5 years (FEVAR 7% vs. EVAR 8%; p > .99), with similar sCr and eGFR up to 5 years. During follow-up, there were more renal artery stenosis/occlusions (15/67 [22%] vs. 3/134 [2%]; p < .001) and renal related re-interventions (12/67 [18%] vs. 4/134 [3%]; p < .001) in patients treated by FEVAR. Rate of progression to renal failure requiring dialysis was low and identical in both groups (1.5% vs. 1.5%; p > .99).

CONCLUSION

Aortic repair with FEVAR and EVAR was associated with similar rates of renal function deterioration in patients with preserved pre-operative renal function. Renal related re-interventions were higher following FEVAR, although net changes in renal function were similar in both groups.

Snorkel endovascular abdominal aortic aneurysm repair versus fenestrated endovascular aneurysm repair: is it a competition?

The endovascular treatment of juxtarenal abdominal aortic aneurysm (AAA) can be performed by either a standard endovascular stent graft with additional snorkle grafts to aorta branches (snorkel endovascular aneurysm repair) or implantation of a fenestrated stent graft (fenestrated endovascular aneurysm repair). While many vascular surgeons consider snorkel endovascular aneurysm repair and fenestrated endovascular aneurysm repair to be competing techniques or alternate strategies, published procedural outcomes suggest more complementary roles. In this clinical review, the advantages and disadvantages of these two approaches are debated, as much can be learned from both strategies. Because the indications and circumstances for juxtarenal AAA repair vary based on patient-specific comorbidities and anatomy, it is recommended that vascular surgeons have access to, and experience with, both treatment strategies. Based on published outcomes, patient outcomes, stent-graft patency, and re-intervention rates are generally similar and acceptable compared with open AAA repair. We conclude that there is a time and a place for both snorkel endovascular aneurysm repair and fenestrated endovascular aneurysm repair for the endovascular management of juxtarenal and pararenal AAA anatomy.

Modular Branched Endograft System for Aortic Aneurysm Repair: Evaluation in a Human Cadaver Circulation Model

A circulation model was created in 6 nonaneurysmal human cadavers to evaluate the deliverability, deployment, and acute performance of a modular branched endograft system for treatment of aortic aneurysms containing essential branch vessels. Two fenestrations were created in an appropriately sized aortic main endograft. Under fluoroscopic guidance, the main endograft was advanced to the target site and the fenestrations were aligned with the ostia of the renal arteries. Branch grafts were placed through the fenestrations into the renal arteries. The outcome was evaluated by post implant angiography and autopsy. Eleven branch grafts were deployed at the target site. All targeted renal arteries showed good patency. At autopsy, all main endografts were adequately deployed, and 10 of 11 branch grafts were locked in place. In this model, deliverability and deployment of the modular branch graft system is feasible in a reliable, predictable, and timely fashion.

Treatment of complex aortic aneurysms with fenestrated endografts and chimney stent repair: Systematic review and meta-analysis

Objective

We reviewed data pertaining to fenestrated endograft technique and chimney stent repair of complex aortic aneurysm for comparative analysis of the outcomes.

Methods

A comprehensive search of relevant databases was conducted to identify articles in English, related to the treatment of complex aortic aneurysm with fenestrated endovascular aneurysm repair and chimney stent repair, published until January 2015.

Results

A total of 42 relevant studies and 2264 patients with aortic aneurysm undergoing fenestrated endovascular aneurysm repair and chimney stent repair were included in our review. A total of 4413 vessels were involved in these processes. The cumulative 30-day mortality was 2.4% and 3.2% ( p = 0.459). The follow-up aneurysm-related mortality was 1.4% and 3.2% ( p = 0.018), and target organ dysfunction was 5.0% and 4.0% in fenestrated endovascular aneurysm repair and chimney stent repair, respectively ( p = 0.27). A total of 156 vessels showed restenosis or occlusion after primary intervention (3.6% and 3.4% in fenestrated endovascular aneurysm repair and chimney stent repair, respectively, p = 0.792). The cumulative type I endoleak was 2.0% (38/1884) after fenestrated endovascular aneurysm repair compared with 3.4% (13/380) after chimney stent repair ( p = 0.092), and the type II endoleak was 5.4% (102/1884) and 5.3% (20/380), respectively ( p = 0.905). Approximately, 1.1% and 1.6% increase in aneurysm was observed following fenestrated endovascular aneurysm repair and chimney stent repair, respectively ( p = 0.437). The re-intervention frequency was 205 and 19 cases after fenestrated endovascular aneurysm repair and chimney stent repair, respectively (11.7%, 5.6%, p = 0.001).

Conclusions

Fenestrated endovascular aneurysm repair and chimney stent repair are safe and effective in treating patients with complex aortic aneurysm. A higher aneurysm-related mortality was observed in chimney stent repair while fenestrated endovascular aneurysm repair was associated with a higher re-intervention rate.

Fenestrated Endografting for Aortic Aneurysm Repair: A 7-Year Experience

Purpose:

To present a 7-year single-center clinical experience with fenestrated endografts and side branches.

Methods:

Between April 1999 and August 2006, 63 patients (57 men; mean age 70.5611.6 years, range 25–89) received custom-designed Zenith fenestrated endoprostheses for a variety of aneurysms (59 abdominal, 1 thoracoabdominal, and 3 thoracic). They were all unsuitable for standard EVAR owing to short aortic necks and high risk for open surgery.

Results:

Nineteen tube grafts and 44 composite bifurcated grafts with a total of 122 fenestrations and 58 side branches were used. Technical success was achieved in 55 (87.3%) patients and in 118 (96.7%) vessels. Treatment success was 93.7%. The mean follow-up was 23±18 months (median 14, range 6–77). Overall, 9 (7.4%) visceral branches were lost: 4 intraoperative, 2 perioperative, and 3 late. There were 12 (19.0%) endoleaks identified: 5 (7.9%: 4 type Ia and 1 fenestration-related type III) primary and 7 (11.1%: 4 type II, 1 type I, and 2 type III) secondary endoleaks; 4 resolved, 4 were treated, and 4 are under observation. At 77 months, 75.3% of patients were free of a reintervention. All reinterventions were performed within the first 14 months. Fourteen cases of renal impairment were seen [6 permanent (only 1 on dialysis) and 8 transient]. One (1.6%) conversion and 1 (1.6%) rupture were recorded; aneurysm-related mortality was 4.8% (3/63).

Conclusion:

The favorable outcomes in this study, which encompasses the team's learning curve with fenestrated endografts and side branches, support the use of these devices in selected patients.

In Vivo Antegrade Fenestration of Abdominal Aortic Stent-Grafts

Purpose:

To examine in a canine model the feasibility of antegrade fenestration of abdominal aortic stent-grafts to preserve the patency of the renal arteries.

Methods:

Two large dogs underwent antegrade fenestration of stent-grafts in the perirenal aorta. Before fenestration, bare stents were inserted in both renal arteries as fluoroscopic landmarks. A 12-mm iliac extension served as the canine aortic endograft. The first procedure was done under ultrasound and fluoroscopic guidance, using an intravascular ultrasound (IVUS) probe inserted in the vena cava and a Pioneer IVUS catheter. The second was performed exclusively under fluoroscopic guidance with a Brockenbrough needle. Angiograms and duplex ultrasound were planned for 1 month, after which the dogs would be sacrificed for autopsy. The explanted endograft was subjected to biomaterials analysis, with a focus on fabric tear.

Results:

Perforation of the aortic graft and catheterization of the renal arteries with a floppy guidewire were possible in both animals. In dog 1, aortic graft dilation and subsequent fenestration were not possible, and the experiment was terminated. However, the procedure was successful in both renal arteries of dog 2. At 1-month follow-up in this dog, both renal arteries were patent. Stent fractures were observed bilaterally. There was no extension of the damage to the fabric beyond the area of fenestration.

Conclusion:

In vivo antegrade fenestration of aortic endografts is technically feasible. However, improvements in technique, instrumentation, and materials are required to make it a reliable and reproducible way of allowing stent-graft vascularization of aortic side branches.

Fenestrated and Branched Grafts for Para-Anastomotic Aortic Aneurysm Repair

Purpose:

To investigate the use of fenestration and branch artery stenting during endovascular stent-graft repair of para-anastomotic aneurysms (PAA).

Methods:

A retrospective review was conducted of 9 patients (all men; mean age 71 years, range 60–80) who received custom-designed fenestrated endoprostheses for PAA repair. Eight tubular fenestrated devices and 1 composite device (fenestrated tube plus modular bifurcated body) with a total of 31 fenestrations were used.

Results:

The mean operating time was 318±93 minutes (range 220–485); the mean fluoroscopy time was 77±38 minutes (range 39–158), during which a mean 121±81 mL (range 33–300) of contrast was used. Technical success was achieved in all cases. Over a mean follow-up of 12±5.5 months (range 6–24), 1 secondary intervention was carried out due to a break in a side branch stent-graft; 2 transient renal impairments and 1 permanent renal insufficiency unrelated to renal artery patency were observed. So far, no vessel loss has emerged.

Conclusion:

Conventional repair of PAA has been a standard procedure for many years, though it carries high surgical risk as well as perioperative mortality. Fenestrated endografts may be a promising alternative in selected patients.

Improving Endograft Stability by Accommodation onto the Aortic Bifurcation

Purpose:

To report the technique for deploying a 3-part endovascular graft onto the native aortic bifurcation for greater stent-graft stability.

Technique:

The Zenith Composite Endovascular Graft is a 3-part system consisting of a proximal tubular body with an uncovered Gianturco Z stent, a distal bifurcated body, and a contralateral leg. Proximally, 8-mm flexible interstent gaps facilitate precise infrarenal aortic placement, even in angulated necks. Technically, the bifurcated part is deployed first and pulled down to the aortic bifurcation, while the tubular main body and contralateral leg deployment follow. Using this technique to accommodate the graft onto the natural aortic bifurcation, distal stability can be enhanced and graft migration minimized.

Conclusion:

The Composite configuration can be an alternative to ensure a higher security index in difficult anatomies. It may be beneficial in patients with short (10–15 mm), angulated (>60°), or conical necks and deserves investigation in these patient populations.

Toward Endografting of the Ascending Aorta: Insight into Dynamics Using Dynamic Cine-CTA

Purpose:

To evaluate pulsatility and movement along the ascending thoracic aorta using dynamic electrocardiographically-gated 64-slice cine computed tomographic angiography (CTA).

Methods:

Diameter and area change and center of mass (COM) movement of the ascending thoracic aorta was determined per cardiac cycle in 15 patients at surgically relevant anatomical levels: (A) 5 mm distal to the coronary arteries, (B) 5 mm proximal to the innominate artery, and (C) halfway up the ascending aorta. Additionally, COM movement was determined 1 cm (level P) and 2 cm (level Q) distal from the origins of the innominate, left carotid, and left subclavian arteries. Eight gated datasets covering the cardiac cycle were used to reconstruct images at each level perpendicular to the aortic lumen. The distance between important anatomical landmarks was determined.

Results:

All levels showed significant cardiac cycle—induced diameter and area changes (p<0.001), with the largest pulsatility 5 mm distal to the coronary arteries. Mean maximum diameter changes were (A) 17.4%±4.8% (range 7.5%–27.5%), (B) 13.9%±3.5% (range 10.6%–25.0%), and (C) 12.9%±3.4% (8.3%–19.6%). Mean area changes were (A) 12.7%±5.5% (range 4.3%–21.8%), (B) 7.5%±2.0% (range 4.1%–11.0%), and (C) 5.6%±2.2% (range 1.9%–11.4%). Mean maximum COM movements were (A) 6.1±2.0 mm (range 2.7–9.0), (B) 2.3±1.1 mm (range 1.1–5.6), and (C) 3.6±1.5 mm (range 1.4–6.5). Mean COM movements of the innominate, left carotid, and left subclavian arteries, respectively, were (P) 1.960.7 mm (range 0.9–3.7), 2.4±0.6 mm (range 1.4–3.3), and 1.9±0.6 mm (range 0.8–2.8), and (Q) 1.8±0.7 mm (range 0.8–3.5), 1.8±0.6 mm (range 0.8–2.7), 1.9±0.6 mm (range 1.1–3.4).

Conclusion:

The dynamics of the ascending thoracic aorta and the arch vessels are impressive, showing a wide range of 3-dimensional motions. Future ascending arch branched and fenestrated thoracic endograft designs must consider this active local environment, as it may have implications for durability, sealing, and ultimate clinical success.

Fenestrated stent grafts for the treatment of complex aortic aneurysm disease: A mature treatment paradigm

The introduction of fenestrated stent grafts (SGs) to treat abdominal aortic aneurysms (AAAs) with short proximal necks began in 1999. Nowadays, the whole visceral aorta can be treated totally by endovascular means. The established use of fenestrated devices to treat complex AAAs as a first-line management option has been previously reported. An up-to-date evaluation of the literature was performed including all types of publications regarding the use of fenestrated technology to repair complex AAAs. Fenestrated repair is now an established alternative to hybrid/chimney/snorkel repairs. However, specific criteria and prerequisites are required for the use and improvement of this method. Multiple device morphologies have been used incorporating the visceral arteries in various combinations. This modular strategy connects different devices (bridging covered stents and bifurcated SGs) with the aortic main body, thus excluding the aneurysm from the circulation. Precise deployment of the fenestrated SG is mandatory for successful visceral vessel revascularization. Accurate SG sizing and customization, a high level of technical skill, and facilities with modern imaging techniques including 3D road mapping and dedicated hybrid rooms are required. Most experience has been with the custom-made Zenith Cook platform, although off-the-shelf devices have been recently implanted. More complex repairs have been performed over the last few years, but device complexity has also increased. Perioperative, mid-term, and a few recently reported long-term results are encouraging. Secondary interventions remain the main problem, similar to that observed after traditional endovascular abdominal aortic aneurysm repair (EVAR).

Systematic Review of Off-the-Shelf or Physician-Modified Fenestrated and Branched Endografts

Purpose: To determine the safety and efficacy of off-the-shelf fenestrated/branched grafts (OSFGs) and physician-modified stent-grafts (PMSGs) for the treatment of complex abdominal aortic aneurysms. Methods: A systematic search of the MEDLINE database via PubMed from January 2001 through March 2015 retrieved 23 relevant articles evaluating the clinical outcomes following the management of patients with pararenal or thoracoabdominal aortic aneurysms. The 15 articles on PMSGs and 8 on OSFGs contained data on 308 patients (mean age 72.93±2.89 years; 213 men). The safety endpoint was major adverse events; the efficacy outcome measure was clinical treatment success (aneurysm exclusion without type I/III endoleak, permanent paralysis, long-term dialysis, or unresolved major complications). Extracted outcome data were pooled and compared between groups; data are given as the pooled proportions and 95% confidence interval (CI). Clinical data are presented as the weighted mean. Results: Of the 308 patients analyzed, almost one third were operated on an emergency basis. The mean aneurysm diameters were 75.9±17.3 mm (range 56–115) for the PMSGs and 68.1±13.7 mm (range 60–100) for the OSFGs. A total of 936 renal and visceral vessels were targeted. Major adverse events (safety) occurred in 24 (12.8%) PMSG patients (95% CI 8.6% to 18.7%) and in 9 (7.4%) OSFG patients (95% CI 3.7% to 14%). Clinical treatment success (efficacy) was observed in 171/187 (91.4%) PMSG patients (95% CI 86.2% to 94.9%) and in 115/121 (95%) OSFG patients (95% CI 89.1% to 98.0%). Corresponding cumulative 30-day target vessel and branch stent perfusion rates were 97.2% (95% CI 95.1% to 98.4%) and 97.6% (95% CI 95.5% to 98.8%) for the PMSG group and 99.6% (95% CI 98.3% to 99.9%) and 98.4% (95% CI 96.5% to 99.4%) for the OSFG group. Six (3.2%) deaths occurred in the PMSG group only; 2 (1.1%) were aneurysm related. Overall branch patency was recorded in 443/458 (96.7%) and in 468/478 (97.9%) of target vessels in the PMSG and OSFG groups, respectively. Conclusion: Off-the-shelf and physician-modified technology seems effective and safe, in both the elective and acute settings, for the treatment of complex aortic aneurysms. Future research within a randomized trial should investigate the true limitations of these devices.

Impact of Fenestrated Endovascular Abdominal Aortic Aneurysm Repair on Renal Function

Purpose: To investigate the impact of fenestrated endovascular aneurysm repair (fEVAR) on renal function perioperatively and at midterm. Methods: A case-controlled study was performed involving 58 patients (mean age 75±7 years; 51 men) who underwent elective fEVAR for a juxtarenal or short-necked abdominal aortic aneurysm (AAA) matched on age, sex, smoking, diabetes, and baseline estimated glomerular filtration rate (eGFR) with a contemporaneous group undergoing open aneurysm repair (OAR) for the same indications. Perioperative incidence of acute kidney injury (AKI) and levels of eGFR at 30 days and 1 year were compared. A systematic literature review was performed to identify studies that had used eGFR as renal outcome after fEVAR; the pooled data were meta-analyzed using an eGFR drop >30% at 1 month and the latest follow-up as endpoints. Results are reported as the pooled proportion and 95% confidence interval (CI). Results: The incidence of AKI after fEVAR was 28% compared to 10% after OAR (p=0.03). Following fEVAR, the mean eGFR dropped from 78±8 to 74±9 mL/min/1.73 m2 at 30 days compared to a change from 79±8 to 80±16 mL/min/1.73 m2 after OAR (p<0.01). However, the absolute drop in eGFR between fEVAR and OAR at 1 year was similar (7 mL/min/1.73 m2; p=0.53); 7% of the fEVAR patients had an eGFR drop >30% at that point compared with none for OAR (p=0.12). The systematic literature review identified eGFR outcomes for 193 fEVAR patients. Combining these patients with the 58 from our cohort study, the pooled proportions of eGFR drop >30% were 20% (95% CI 9% to 39%) at 30 days and 8% (95% CI 0.5% to 13%) at the end of follow-up. Conclusion: fEVAR has a significant perioperative impact on renal function, but 1-year results are similar to OAR. fEVAR patients may benefit from targeted AKI prevention strategies that need to be assessed in relevant studies.

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.

Editor's choice - thirty day outcomes and costs of fenestrated and branched stent grafts versus open repair for complex aortic aneurysms

OBJECTIVE

To compare 30 day outcomes and costs of fenestrated and branched stent grafts (f/b EVAR) and open surgery (OSR) for the treatment of complex abdominal aortic aneurysms (AAA) and thoraco-abdominal aortic aneurysms (TAAA).

METHODS

The multicenter prospective registry WINDOW was set up to evaluate f/b EVAR in high risk patients with para/juxtarenal AAA, and infradiaphragmatic and supradiaphragmatic TAAA. A control group of patients treated by OSR was extracted from the national hospital discharge database. The primary endpoint was 30 day mortality. Secondary endpoints included severe complications, length of stay, and costs. Mortality was assessed by survival analysis and uni/multivariate Cox regression analyses using pre- and post-operative characteristics. Bootstrap methods were used to estimate the cost-effectiveness of f/b EVAR versus OSR.

RESULTS

Two hundred and sixty eight cases and 1,678 controls were included. There was no difference in 30 day mortality (6.7% vs. 5.4%, p = 0.40), but costs were higher with f/b EVAR (€38,212 vs. €16,497, p < .001). After group stratification, mortality was similar with both treatments for para/juxtarenal AAA (4.3% vs. 5.8%, p = .26) and supradiaphragmatic TAAA (11.9% vs. 19.7%, p = .70), and higher with f/b EVAR for infradiaphragmatic TAAA (11.9% vs. 4.0%, p = .010). Costs were higher with f/b EVAR for para/juxtarenal AAA (€34,425 vs. €14,907, p < .0001) and infradiaphragmatic TAAA (€37,927 vs. €17,530, p < .0001), but not different for supradiaphragmatic TAAA (€54,710 vs. €44,163, p = .18).

CONCLUSION

f/b EVAR does not appear justified for patients with para/juxtarenal AAA and infradiaphragmatic TAAA fit for OSR but may be an attractive option for patients with para/juxtarenal AAA not eligible for surgery and patients with supradiaphragmatic TAAA.

CLINICAL TRIAL REGISTRATION

http://www.clinicaltrials.gov/ct2/show/NCT01168037; identifier: NCT01168037 (WINDOW registry).

Impact of intraoperative adverse events during branched and fenestrated aortic stent grafting on postoperative outcome

Objective

Fenestrated and branched endovascular devices are increasingly used for complex aortic diseases, and despite the challenging nature of these procedures, early experiences from pioneering centers have been encouraging. The objectives of this retrospective study were to report our experience of intraoperative adverse events (IOAEs) during fenestrated and branched stent grafting and to analyze the impact on clinical outcomes.

Methods

Consecutive patients treated with fenestrated and branched stent grafting in a tertiary vascular center between February 2006 and October 2013 were evaluated. A prospectively maintained computerized database was scrutinized and updated retrospectively. Intraoperative angiograms were reviewed to identify IOAEs, and adverse events were categorized into three types: target vessel cannulation, positioning of graft components, and intraoperative access. Clinical consequences of IOAEs were analyzed to ascertain whether they were responsible for death or moderate to severe postoperative complications.

Results

During the study period, 113 consecutive elective patients underwent fenestrated or branched stent grafting. Indications for treatment were asymptomatic complex abdominal aortic aneurysms (CAAAs, n = 89) and thoracoabdominal aortic aneurysms (TAAAs, n = 24). Stent grafts included fenestrated (n = 79) and branched (n = 17) Cook stent grafts (Cook Medical, Bloomington, Ind), Ventana (Endologix, Irvine, Calif) stent grafts (n = 9), and fenestrated Anaconda (Vascutek Terumo, Scotland, UK) stent grafts (n = 8). In-hospital mortality rates for the CAAA and TAAA groups were 6.7% (6 of 89) and 12.5% (3 of 24), respectively. Twenty-eight moderate to severe complications occurred in 21 patients (18.6%). Spinal cord ischemia was recorded in six patients, three of which resolved completely. A total of 37 IOAEs were recorded in 34 (30.1%) patients (22 CAAAs and 12 TAAAs). Of 37 IOAEs, 15 (40.5%) resulted in no clinical consequence in 15 patients; 17 (45.9%) were responsible for moderate to severe complications in 16 patients, and five (13.5%) led to death in four patients. The composite end point death/nonfatal moderate to severe complication occurred more frequently in patients with IOAEs compared with patients without IOAEs (20 of 34 vs 12 of 79; P < .0001).

Conclusions

In this contemporary series, IOAEs were relatively frequent during branched or fenestrated stenting procedures and were often responsible for significant complications.