Endoluminal aortic grafting with renal and superior mesenteric artery incorporation by graft fenestration

Early Institutional Experience with One-Piece Bifurcated-Fenestrated Stentgraft in the Treatment of Abdominal Aortic Aneurysms

PURPOSE

To review the early experience of the use of a bifurcated-fenestrated endograft (Bif-FEVAR) to treat abdominal aortic aneurysms (AAA) in a high-volume aortic center.

METHODS

A retrospective single-center analysis was conducted between March 2019 and April 2021 including consecutive patients that underwent Bif-FEVAR. Only patients without a proper infrarenal neck and a distance <70 mm between the lowest target artery and the native or prosthetic aortic bifurcation were considered. All Bif-FEVAR custom-made devices were manufactured by Cook Medical (Inc., Bloomington, Indiana). Demographics, anatomical features, technical success, major adverse events, 30-day mortality, and survival according to Kaplan-Meier were analyzed according to Society for Vascular Surgery standards.

RESULTS

Overall, 10 patients (100% male with median age 78) were included. The median preoperative maximal aneurysm diameter was 68 mm [51-84]. Eight patients were treated for a proximal type I endoleak after endovascular aneurysm repair. A total of 36 fenestrations were planned. The median operative time was 144 min [127-168], with a median fluoro time of 40.5 min [34-54] and a median dose area product of 73 Gy cm2 [61-89]. Technical success rate was 100%. No patients experienced a major postoperative adverse event. Median follow-up time was 8 months [6-13].

CONCLUSION

Bif-FEVAR is technically feasible when there is a short distance below the lowest target artery and the aortic bifurcation, with favorable short-term results.

CLINICAL IMPACT

This study assessed the use of an innovative one-piece bifurcated fenestrated stent-graft as a primary procedure or in the treatment of proximal endoleak after standard infrarenal EVAR. We demonstrated these custom-made devices can be used safely with favorable short-term results. One-piece bifurcated fenestrated stent-grafts extend the indications of FEVAR for patients with an unusually short distance between the lowest renal artery and the aorto-iliac bifurcation or the diverter flow of a preexisting bifurcated infrarenal stent-graft.

Bibliometric analysis of the top 100 most-cited articles on branch reconstruction in endovascular aortic repair

With the global acceptance of endovascular aortic repair (EVAR) for aortic diseases, one of the most common issues in EVAR is the preservation of critical aortic branches. Despite the fact that many studies on EVAR-assisted endovascular branch reconstruction techniques have been published. There were few bibliometric analyses that focused on branch rebuilding in endovascular aortic repair. In this study, we aim to analyze the characteristics of the 100 most-cited articles on branch reconstruction in Endovascular Aortic Repair. The most popular articles retrospectively searched on the Web of Science were published between 1999 and 2018, with 10480 citations in total (an average of 551.58 citations per year). The top-cited article was 281 citations. The peak years of citations was 2019 (1051 citations). Journal of Vascular Surgery published the most articles (46 articles) and was the most-cited journal (5055 citations), and the United States was the country with the greatest number of publications (43 articles). Cleveland Clinic was the most influential institution with 20 articles. Fenestration technique was the major topic area of interest and trend (63 articles mentioned). Customised device was the most widely used endograft (52 articles mentioned). Renal artery was the most frequently reconstructed branch of aorta (70 articles mentioned). Our analysis showed the endovascular branch reconstruction in EVAR developed rapidly over the past 20 years. Continued exploration and cooperation between specialties and manufacturers on endograft design and modifications will further enhance knowledge of disease intervention and treatment.

Five-year outcomes of physician-modified endografts for repair of complex abdominal and thoracoabdominal aortic aneurysms

OBJECTIVE

There is paucity of data on the durability of physician modified endografts (PMEGs) for complex abdominal (CAAAs) and thoracoabdominal aortic aneurysms (TAAAs) despite widespread use. The aim of this study was to evaluate and compare the early and long-term outcomes of fenestrated-branched endovascular aortic repair (FB-EVAR) for CAAAs and TAAAs using PMEGs.

METHODS

We reviewed clinical data and outcomes of patients treated by FB-EVAR using PMEGs for CAAAs (defined as short-neck infrarenal, juxtarenal, and pararenal AAAs) and TAAAs between 2007 and 2019. All patients were treated by a dedicated team with extensive manufactured device experience. Endpoints included 30-day mortality and major adverse events, patient survival and freedom from aortic-related mortality (ARM), freedom from secondary intervention, target artery (TA) patency, and freedom from TA endoleak and TA instability.

RESULTS

Of 645 patients undergoing FB-EVAR, 156 patients (24%) treated with PMEG (121 males; mean age, 75 ± 8 years) were included. There were 89 CAAAs, 33 extent IV TAAAs and 34 extent I to III TAAAs. A total of 452 renal-mesenteric targets (3.1 ± 1.0 vessels/patient) were incorporated. Patients with TAAAs had significantly (P < .05) larger aneurysms (73 ± 11 vs 68 ± 14 mm), more TAs incorporated (3.4 ± 0.9 vs 2.8 ± 1.0), and more often had previous aortic repair (54% vs 27%). Technical success was higher in patients treated for CAAAs (99% vs 91%; P = .04). Thirty-day and/or in-hospital mortality was 5.7% and was significantly lower for CAAAs compared with TAAAs (2% vs 10%; P = .04), with three of nine early mortalities (33%) among patients treated emergently. After a mean follow-up of 49 ± 38 months, there were 12 aortic-related deaths (7.6%), including nine early deaths (5.7%) from perioperative complications and three late deaths (1.9%) from rupture. At 5 years, patient survival was 41%. Patients treated for CAAAs had higher 5-year freedom from ARM (P = .016), TA instability (P = .05), TA endoleak (P = .01), and TA secondary interventions (P = .05) with a higher, but non-significant, freedom from sac enlargement ≥5 mm (P = .11). Primary and secondary TA patency was 91% ± 2% and 99% ± 1%, respectively. Sac regression ≥5 mm occurred in 67 patients (43%) and was associated with increased survival (hazard ratio, 0.54; 95% confidence interval, 0.37-0.80) compared with those without sac regression.

CONCLUSIONS

FB-EVAR using PMEGs was performed with acceptable long-term outcomes. Overall patient survival was low due to significant underlying comorbidities. Patients treated for CAAAs had higher freedom from ARM, TA instability, TA endoleak, TA secondary interventions, and a trend towards higher freedom from sac enlargement compared with patients treated for TAAAs. Sac regression was associated with improved patient survival.

Branched and Fenestrated Aortic Endovascular Grafts

Endovascular repair of abdominal and descending thoracic aortic aneurysms has become the standard of care due to improvements in morbidity and mortality compared to open surgical repair. Late durability, however, remains an issue because persistent endoleaks can lead to continued aneurysm expansion and eventual rupture, sometimes years following the original repair. Branched, fenestrated, and physician-modified endografts in the thoracic arch and thoracoabdominal aorta have extended the seal zone in order to mitigate the risks of proximal and distal endoleaks. This review summarizes the current state of branched, fenestrated, and physician-modified endografts used in complex aortic pathologies.

Thoracoabdominal Aortic Disease and Repair: JACC Focus Seminar, Part 3

Thoracoabdominal aortic disease is a rare but life-threatening condition that requires expert multidisciplinary collaborative management. Intervention is indicated in patients with symptomatic aneurysms or when an aneurysm reaches a certain threshold of diameter or rate of expansion. The strategies for spinal cord and end-organ protection have evolved over several decades, resulting in improved outcomes after repair. Open repair, although invasive, provides definitive and durable repair. Endovascular approaches are rapidly evolving, and the results with fenestrated and branched endografts are promising. Both open repair and endovascular repair require highly specialized expertise, and outcomes are best when repair is undertaken in an elective setting by a dedicated team. Patients with degenerative thoracoabdominal aortic aneurysms and chronic dissections should be followed up closely and referred for elective repair when indicated.

Peri-Operative Management of Patients Undergoing Fenestrated-Branched Endovascular Repair for Juxtarenal, Pararenal and Thoracoabdominal Aortic Aneurysms: Preventing, Recognizing and Treating Complications to Improve Clinical Outcomes

The advent and refinement of complex endovascular techniques in the last two decades has revolutionized the field of vascular surgery. This has allowed an effective minimally invasive treatment of extensive disease involving the pararenal and the thoracoabdominal aorta. Fenestrated-branched EVAR (F/BEVAR) now represents a feasible technical solution to address these complex diseases, moving the proximal sealing zone above the renal-visceral vessels take-off and preserving their patency. The aim of this paper was to provide a narrative review on the peri-operative management of patients undergoing F/BEVAR procedures for juxtarenal abdominal aortic aneurysm (JAAA), pararenal abdominal aortic aneurysm (PRAA) or thoracoabdominal aortic aneurism (TAAA). It will focus on how to prevent, diagnose, and manage the complications ensuing from these complex interventions, in order to improve clinical outcomes. Indeed, F/BEVAR remains a technically, physiologically, and mentally demanding procedure. Intraoperative adverse events often require prolonged or additional procedures and complications may significantly impact a patient's quality of life, health status, and overall cost of care. The presence of standardized preoperative, perioperative, and postoperative pathways of care, together with surgeons and teams with significant experience in aortic surgery, should be considered as crucial points to improve clinical outcomes. Aggressive prevention, prompt diagnosis and timely rescue of any major adverse events following the procedure remain paramount clinical needs.

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.

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.

Final 5-year results of the United States Zenith Fenestrated prospective multicenter study for juxtarenal abdominal aortic aneurysms

PURPOSE

To report 5-year results of the prospective, multicenter study designed to evaluate the Zenith Fenestrated AAA Endovascular Graft (William A. Cook Australia, Brisbane, Australia) for juxtarenal abdominal aortic aneurysms (AAAs).

METHODS

Sixty-seven patients (54 male, mean age 74 ± 8 years) were prospectively enrolled at 14 U.S. centers from 2005 to 2012. Fenestrated stent grafts were used in patients with infrarenal aortic neck lengths of 4 to 14 mm to target 178 renal-mesenteric arteries with a mean of 2.7 vessels per patient. At 5 years, 42 of the 67 patients completed the final study follow-up, with clinical examination obtained in 41 and computed tomography imaging in 39. Outcomes adjudicated by a clinical events committee included all-cause and aneurysm-related mortality, major adverse events, renal stent occlusion/stenosis, renal function changes and renal infarcts, aneurysm sac enlargement (>5 mm), device migration (≥10 mm), type I/III endoleak, and secondary interventions.

RESULTS

Median follow-up was 59.8 months (range, 0.1-67.5 months). There were seven deaths, including one (1.5%) within 30 days (procedure-related) and six beyond 30 days (not procedure-related in five, indeterminate in one). At 5 years, freedom from all-cause mortality was 88.8 ± 4.2% and freedom from aneurysm-related mortality was 96.8 ± 2.3%. There were no aneurysm ruptures or conversions to open surgery. Of the 129 renal arteries targeted by fenestrations, five (4%) occluded and 14 (11%) developed in-stent stenosis. Treatment included redo stenting/angioplasty in 13 vessels, renal artery bypass in 2 vessels, and failed thrombectomy in 1 vessel. Primary and secondary renal target patency was 82.7 ± 4.1% and 95.7 ± 2.1% at 5 years, respectively. Dialysis was required in one patient who had pre-existing chronic kidney disease. During the 5 years, there was 1 type IA endoleak (1.5%), 1 type IB endoleak (1.5%), 2 device migrations (3%), and 4 aneurysm sac enlargements (6%). Overall, 81% of patients had sac shrinkage at 5 years. Of 20 patients who underwent secondary interventions, 12 were for renal in-stent stenosis or occlusion, 7 were for endoleak, and 1 was for both indications. Freedom from secondary intervention was 63.5 ± 7.2% at 5 years.

CONCLUSIONS

These 5-year results confirm the safety and effectiveness of the Zenith Fenestrated AAA stent graft with no late graft- or aneurysm-related deaths. In-stent stenosis of bare metal renal stents was the most frequent indication for secondary intervention. The low rate of type IA endoleak, sac enlargement, and device migration support its use in patients with juxtarenal AAAs.

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.

Use of 3D Printing to Guide Creation of Fenestrations in Physician-Modified Stent-Grafts for Treatment of Thoracoabdominal Aortic Disease

Purpose: To summarize the experience and outcomes of total endovascular repair of thoracoabdominal aortic disease using 3-dimensional (3D) printed models to guide on-site creation of fenestrations in aortic stent-grafts. Materials and Methods: From April 2018 to March 2019, 34 patients (mean age 58±14 years; 24 men) with thoracoabdominal aortic disease were treated in our department. Nineteen patients had thoracoabdominal aortic dissection and 15 had thoracoabdominal aortic aneurysm. Preoperatively, a 3D printed model of the aorta was made according to computed tomography images. In the operating room, the main aortic stent-graft was completely released in the 3D printed model, and the position of each fenestration or branch was marked on the stent-graft. The fenestrations were then made using an electric pen. Wires were sewn to the edge of the fenestrations using nonabsorbable sutures. After customization, the aortic stent-graft was reloaded into the delivery sheath and deployed. Results: The printing process took ~5 hours (1 hour for image reconstruction, 3 hours for printing, and 1 hour for postprocessing). The physician-modified stent-grafts had a total of 107 fenestrations secured by 102 bridging stent-grafts, including 73 covered stents and 29 bare stents. The average procedure time was 5.6±1.2 hours, including a mean 1.3 hours for stent-graft customization. No renal insufficiency or paraplegia occurred. Two branch arteries were lost during the operation. One patient (3%) died 1 week after surgery from a retrograde dissection rupture. One patient developed a minor cerebral infarction postoperatively. The mean follow-up time was 8.5 months. There was 1 endoleak from a fenestration (coil embolized) and 4 distal ruptures of the aortic dissection (3 treated and 1 observed). Conclusion: Three-dimensional printing can be used to guide creation of fenestrated stent-grafts for the treatment of thoracoabdominal aortic diseases involving crucial branches. This technique appears to be more accurate than the traditional measurement method, with short-term follow-up demonstrating the safety and reliability of the method. However, further research and development are needed.

The Relationship Between Operative Volume and Peri-operative Mortality After Non-elective Aortic Aneurysm Repair in Australia

OBJECTIVE

Hospital and surgeon operative caseload is thought to be associated with peri-operative mortality following the non-elective repair of aortic aneurysms; however, whether such an association exists within the Australian healthcare setting is unknown.

METHODS

The Australasian Vascular Audit was interrogated to identify patients undergoing non-elective (emergency [EMG] or semi-urgent [URG]) aortic aneurysm repair between 2010 and 2016, as well as their treating surgeon and hospital. Hierarchal logistic regression modelling was used to assess the impact of caseload on outcomes after both endovascular (EVAR) and open surgical repair (OSR).

RESULTS

Volume counts were determined from 14 262 patients (4 121 OSR and 10 141 EVAR). After exclusion of elective procedures and duplicates, 1 153 EVAR (570 EMG and 583 URG) and 1 245 OSR (946 EMG and 299 URG) non-elective cases remained for the analysis. Crude mortality was 24.0% following OSR (EMG 29.2%; URG 7.7%) and 7.5% following EVAR (EMG 12.6%; URG 2.4%). Univariable analysis demonstrated an association between OSR mortality and hospital volume (quintile [Q] 1: 25.3%, Q2: 27.8%, Q3: 23.9%, Q4: 27.0%, Q5: 16.2%; p = .030), but not surgeon (Q1: 25.2%, Q2: 27.4%, Q3: 26.0%, Q4: 21.4%, Q5: 19.5%, p = .32). Multivariable analysis confirmed this association (odds ratio (OR) [95% CI]; Q1 vs 5: 1.91 [1.13-3.21], Q2 vs. 5: 2.01[1.24-3.25], Q3 vs. 5: 1.41 [0.86-2.29], Q4 vs. 5: 1.92 [1.17-3.15]; p = .020). The difference was most pronounced in the EMG OSR group [Q1 - 3 vs. 4-5] (OR 1.63 [1.07-2.48]; p = .020). Mortality after EVAR was not associated with either hospital (Q1: 6.3%, Q2: 10%, Q3: 6.8%, Q4: 4.5%, Q5: 10%; p = .14) or surgeon volume (Q1: 9.3%, Q2: 5.7%, Q3: 8.1%, Q4: 7.0%, Q5: 7.3%; p = .67).

CONCLUSION

There is an inverse correlation between hospital volume and peri-operative mortality following EMG open repair of aortic aneurysm. These data support restructuring Australian pathways of care to direct suspected ruptured aneurysm to institutions that reach a minimum volume threshold.

Duplex ultrasound follow-up after fenestrated and branched endovascular aneurysm repair (FEVAR and BEVAR)

Endovascular aneurysm repair (EVAR) is now the predominant method for treatment of infrarenal abdominal aortic aneurysms. Although EVAR has numerous advantages over standard open surgical repair, it also exposes patients to risks such as aneurysm sac enlargement, endoleaks, and graft migration, which make surveillance or follow-up mandatory. Fenestrated (FEVAR) and branched (BEVAR) endografts have extended the application of EVAR to juxtarenal, pararenal/paravisceral, and thoracoabdominal aneurysms, with some complex aneurysms requiring combined approaches (F-BEVAR). Duplex ultrasound has been recommended as an alternative to frequent computed tomography imaging for EVAR follow-up when it can provide the clinically necessary information. The major components of a post-EVAR duplex examination include measurement of aortic aneurysm sac size, assessment for endoleak, and evaluation of the endograft for patency and integrity. The duplex protocol for EVAR follow-up can be extended for follow-up after FEVAR, BEVAR, and F-BEVAR, with additional attention to the device components associated with fenestrations and branches. At the University of Washington, the physician-modified endovascular graft approach has been used for FEVAR. During these procedures, covered stents are placed in the renal arteries through fenestrations and the superior mesenteric artery is perfused through a fenestration, but typically remains unstented. Duplex scanning of the renal and mesenteric arteries has been performed preoperatively and at 30 days, 6 months, 1 year, and annually. In a review of patients having covered stents placed in non-stenotic renal arteries during FEVAR, both peak systolic velocity and the renal to aortic velocity ratio remained below the standard significant stenosis threshold in most patients. The duplex velocity criteria for stenosis in native renal arteries appeared to overestimate the severity of stenosis in renal artery covered stents. The unstented superior mesenteric artery remained widely patent in the presence of fenestrations or crossing struts and was not associated with endoleaks. Duplex ultrasound protocols for follow-up after FEVAR, BEVAR, and F-BEVAR can be based on those that have been established for standard EVAR, along with assessment of fenestrations and branches, as well as patency of the renal and mesenteric arteries.

Learning curve of fenestrated and branched endovascular aortic repair for pararenal and thoracoabdominal aneurysms

OBJECTIVE

The objective of this study was to review the learning curve for fenestrated-branched endovascular aortic repair (F-BEVAR) of pararenal and thoracoabdominal aortic aneurysms (TAAAs).

METHODS

We reviewed the clinical data of 334 consecutive patients (255 males, mean age 75 ± 7 years) who underwent F-BEVAR between 2007 and 2016 in a single institution. Outcomes were analyzed in four quartiles of experience (Q1-Q4). Study outcomes included trends in patient characteristics, device design, procedural variables, 30-day mortality, and major adverse events (MAEs).

RESULTS

There were 178 patients (53%) treated for pararenal aneurysms and 156 (47%) for TAAAs. During the study period, there was a statistically significant increase in the proportion of TAAAs and in the number of vessels incorporated. Despite this, there was a steady decrease in 30-day mortality (6% in Q1 to 0% in Q4; P < .04) and in the rate of MAEs (60% in Q1 to 29% in Q4; P<.001). By linear regression analysis, there was significant decline in estimated blood loss (1358 ± 1517 mL in Q1 to 486 ± 520 mL in Q4; P < .001), total operating time (325 ± 116 minutes in Q1 to 248 ± 92 minutes in Q4; P < .001), total fluoroscopy time (121 ± 59 minutes in Q1 to 85 ± 39 minutes in Q4; P < .001), contrast volume (201 ± 92 mL in Q1 to 160 ± 61 mL in Q4; P = .002), and radiation dose (4141 ± 2570 mGy in Q2 to 2543 ± 1895 mGy in Q4; P < .001). Independent predictors of MAEs were total operating time (odds ratio [OR], 1.6; 95% confidence interval [CI], 1.3-1.8; P < .001), Society for Vascular Surgery total score (OR, 1.1; 95% CI, 1.02-1.2; P = .009), and quartile 1 (OR, 3.0; 95% CI, 1.7-5.2; P < .001).

CONCLUSIONS

This study demonstrates significant improvement in perioperative mortality, MAEs, procedural variables, and secondary interventions in patients treated by F-BEVAR, despite the increase in complexity of aneurysm pathology during the study period. Also, better patient selection contributed to improve outcomes.

Current status of endovascular treatment for thoracoabdominal aortic aneurysms

Open surgical repair (OSR) for thoracoabdominal aortic aneurysms (TAAAs) is maximally invasive and associated with high rates of operative mortality and perioperative complications including spinal cord ischemia (SCI), despite improvements in surgical techniques and perioperative care. Elderly patients, patients with a history of aortic surgery, and patients with severe comorbidities are often considered ineligible for this surgery and endovascular treatment may be their only treatment option. Total endovascular aneurysm repair (t-EVAR) without debranching surgery does not require thoracotomy and laparotomy and could improve the outcomes of these patients. t-EVAR includes fenestrated EVAR (f-EVAR), multi-branched EVAR (b-EVAR), and physician-modified fenestration endograft (PMFG). Although these techniques have achieved lower mortality rates than OSR, there are concerns about perioperative complications including limb ischemia, SCI, and long-term outcomes such as endograft migration and endoleaks (ELs). This article provides an overview of available endovascular devices for TAAAs and reviews the short and mid-term results of t-EVAR, as well as alternative options.

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

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

Imaging Obtained Up To 12 Months Preoperatively Is Adequate for Planning Fenestrated/Branched Endovascular Aortic Aneurysm Repair

OBJECTIVES

Patients referred for fenestrated/branched endovascular aortic repair (F/BEVAR) often present with a previous computed tomography angiogram (CTA), but it is unknown how recent the CTA must be to ensure accurate F/BEVAR planning. We sought to determine whether anatomic planning parameters change significantly between a CTA used for F/BEVAR planning and a CTA obtained 6 to 12 months prior.

METHODS

Two blinded observers reviewed preoperative CTAs from 21 patients who underwent F/BEVAR. Each patient had a "recent" scan obtained 0 to 6 months before F/BEVAR planning and a "prior" scan obtained 6 to 12 months before the "recent" CTA. Standard measurements included (1) target vessel separation distances, (2) target vessel origin clock position, and (3) proximal F/BEVAR device diameter. Clinically significant differences for target vessel separation distance, target vessel origin clock position, and proximal F/BEVAR device diameter were predefined as >5 mm, >30 minutes, and >4 mm, respectively. Differences between "recent"/"prior" CTA scans were examined by paired t test.

RESULTS

Mean time interval between paired "recent"/"prior" CTAs was 8.0 months (standard deviation: ±1.7). Mean difference in paired "recent"/"prior" target vessel distance (relative to celiac artery [CA]) was 2.6 mm for the superior mesenteric artery (SMA), 2.5 mm for the right renal artery (RRA), and 3.3 mm for the left renal artery (LRA). Of the 21 paired "recent"/"prior" CTAs, clinically significant differences were observed in 2, 4, and 2 patients for SMA, RRA, and LRA target vessel distance, respectively. Target vessel clock position (SMA reference at 12:00) varied by 12 minutes for the CA, 13 minutes for the RRA, and 15 minutes for the LRA. One paired "recent"/"prior" CTA was found to have a clinically significant difference for the LRA. No clinically significant differences were observed for proximal device diameter.

CONCLUSIONS

In patients who underwent successful F/BEVAR, measurement comparisons between CTAs obtained up to 1 year prior were minor and unlikely to yield clinically significant changes to F/BEVAR design.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Correlations Between Branch Vessel Catheterization and Procedural Complexity in Fenestrated and Branched Endovascular Aneurysm Repair

Introduction:

The use of fenestrated and branched endovascular technologies in complex aortic aneurysm repair (F/BEVAR) is increasing, with a trend toward using longer sealing zones and incorporating more target vessels. Successful aneurysm exclusion and prevention of long-term treatment failure need to be balanced against the increased complexity of more extensive procedures. The aim of this study was to analyze relationships between the number of catheterized vessels and multiple operative variables as a means for evaluating procedural complexity.

Methods:

Operative data from consecutive F/BEVAR procedures performed at a single center from 2012 to 2015 were analyzed. An equal number of EVAR procedures, randomly selected, from this period were also analyzed. Only intact aneurysms were included. Complex aneurysms were grouped based on the required number of target vessel catheterization. Ten procedural variables, categorized as perioperative, postoperative, and radiologic-related, were compared. Pearson correlation analysis and regression analysis were performed. The correlation coefficients, r, were classified using Cohen boundaries, r ≥ 0.5 indicating a strong relationship.

Results:

There were 63 EVAR, 40 FEVAR, and 22 BEVAR procedures. There was no significant difference in patient comorbidities between conventional EVAR and complex procedure groups. The complex procedures included 23 two-vessel, 20 three-vessel, and 19 four-vessel catheterizations. Strong linear relationships between the number of branch vessel catheterizations and the following variables were identified: accumulated skin dose ( r = .504), contrast volume ( r = .652), fluoroscopy duration ( r = .598), number of angiography series ( r = .650), anesthesiology duration ( r = .742), procedure duration ( r = .554), and total length of stay ( r = .533).

Conclusion:

The complexity of FEVAR and BEVAR procedures reveals strong correlations between multiple peri- and postoperative variables. These exposures and risks should be borne in mind when considering treatment of complex abdominal aortic aneurysms as well as long-term clinical outcomes.

Identifying and addressing the limitations of EVAR technology

INTRODUCTION

Endovascular aortic repair (EVAR) has improved over the last two decades. Approximately 80% of the patients presenting with an abdominal aortic aneurysm (AAA) is nowadays primarily treated with EVAR.

AREAS COVERED

In this review, the differences between endovascular and open repair, the clinical characteristics needed for EVAR, the role of clinical imaging and the developments in EVAR technology will be discussed. Early mortality is lower in EVAR as compared to open repair, whereas this benefit is lost after 3 years postoperatively. EVAR comes with a high reintervention rate, with endoleak being the most important predictive factor for reintervention. Expanding technical possibilities have allowed surgeons to choose from a palate of endovascular approaches in aneurysm patients with challenging anatomies.

EXPERT COMMENTARY

Although EVAR has taken a giant leap forward in development, the new developments have seemed to surpass the long-term limitations with older devices. It is important to start focusing on the current limitations of EVAR, in particular the durability of devices in the human variable anatomic and dynamic environment.

Single-center experience with complex abdominal aortic aneurysms treated by open or endovascular repair using fenestrated/branched endografts

OBJECTIVE

The objective of this study was to evaluate outcomes of patients with complex abdominal aortic aneurysms (cAAAs) treated with open repair (OR) or fenestrated/branched endovascular aneurysm repair (F/B-EVAR) from a single center.

METHODS

A retrospective analysis of consecutive patients with cAAAs treated electively by OR or F/B-EVAR between January 2010 and February 2017 was conducted. Demographics of the patients, cardiovascular risk factors, procedure time, number of vessels incorporated, radiation dose, estimated blood loss, intensive care unit (ICU) length of stay (LOS), and hospital LOS were recorded. End points included target vessel patency, aneurysm rupture, freedom from reintervention, and major adverse events (MAEs).

RESULTS

During this period, 153 patients (OR, 69; F/B-EVAR, 84) underwent repair of cAAA. The majority were male (OR, 55; F/B-EVAR, 64), with a mean age of 75.8 ± 7.6 years (F/B-EVAR) and 71.2 ± 7.9 years (OR). Patients in the F/B-EVAR group were more likely to be American Society of Anesthesiologists class 3 and 4 (60% vs 0%; P < .001) and had a higher median Society for Vascular Surgery/American Association for Vascular Surgery comorbidity severity score (15 vs 7; P < .001). A total of 235 vessels were targeted in the F/B-EVAR group, with a technical success of 97.6%. Thirty-one patients in the OR group required concomitant renal artery revascularization. Transfusion requirements (100% vs 1.2%), MAEs (40.6% vs 13.1%), procedure length (304 minutes vs 140 minutes), estimated blood loss (2246 mL vs 165 mL), ICU LOS (3 days vs 1 day), and hospital LOS (7 days vs 2 days) were higher (P < .001) in the OR group compared with the F/B-EVAR group. The 30-day mortality was 2.9% and 2.4% (P = .84) in the OR group and F/B-EVAR group, respectively. Supraceliac clamp site was associated with increased incidence of postoperative renal insufficiency. A decrease in procedure time, contrast volume, fluoroscopy time, and fluoroscopy dose was noted in the F/B-EVAR group with increasing experience even as case complexity increased. More patients were discharged home after F/B-EVAR (97.6% vs 59.4%; P < .001). With a mean follow-up of 31 months (F/B-EVAR, 17 months; OR, 48 months), the rate of secondary intervention was 3.7% and 5.8% (P = NS) for F/B-EVAR and OR, respectively. Freedom from branch instability and reintervention was 99% (95% confidence interval, 96.2%-99.8%) and 96% (95% confidence interval, 87.1%-98.6%), respectively.

CONCLUSIONS

Results of this "real-world" experience suggest that the use of F/B-EVAR for the treatment of cAAAs in high-risk surgical patients is safe and effective and has comparable short-term results to those of low-risk patients undergoing OR. Patients treated by F/B-EVAR had shorter ICU and hospital LOS, lower MAEs, and faster convalescence. A decrease in procedure time and radiation dose was noted as experience was gained, even as complexity increased.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Fenestrated and Branched Aortic Grafts

BACKGROUND

Abdominal and thoracic aortic aneurysms are diagnosed in 40 and 10 to 15 out of 100 000 persons per year, respectively. Fenestrated (fEVAR) and branched (bEVAR) stent grafts have been developed for abdominal juxtarenal and thoracoabdominal aneurysms. We discuss the patency and complication rates of fEVAR and bEVAR procedures and compare them with the outcome of open surgery.

METHODS

This review is based on pertinent publications from 2011 to 2014 that were retrieved by a selective literature search. The clinical outcomes of case series involving a total of more than 1500 patients are presented. The discussion takes account of recommendations contained in the literature and the authors' own experience.

RESULTS

Open surgery and aortic stent grafting have not been compared in any randomized trial to date. We identified 7 clinical series that included a total of 1270 fEVAR patients and 5 with a total of 408 bEVAR patients. The perioperative mortality after fEVAR procedures was 0-4%. Spinal cord ischemia arose in 1% of cases. The stent patency rate in visceral vessels ranged from 93 to 98%. bEVAR procedures were associated with both higher mortality (4-7%) and more common spinal cord ischemia (4-13%). 5-8% of all patients needed dialysis perioperatively, and the stent patency rate in visceral vessels was 94-97%. Preoperative renal insufficiency was a risk factor for peri-interventional death. Impaired renal function after fEVAR/bEVAR procedures was mainly associated with intermittent lower limb ischemia.

CONCLUSION

The results of fEVAR/bEVAR procedures in the last 5 years are similar to those of open surgery. The high postoperative rate of spinal cord ischemia remains a serious problem in the endovascular treatment of thoracoabdominal aortic aneurysms. The decision to implant a stent graft by an endovascular approach or to treat surgically should be made on a case-to-case basis in an interdisciplinary vascular conference.

Prospective, nonrandomized study to evaluate endovascular repair of pararenal and thoracoabdominal aortic aneurysms using fenestrated-branched endografts based on supraceliac sealing zones

PURPOSE

To investigate outcomes of manufactured fenestrated and branched endovascular aortic repair (F-BEVAR) endografts based on supraceliac sealing zones to treat pararenal aortic aneurysms and thoracoabdominal aortic aneurysms (TAAAs).

METHODS

A total of 127 patients (91 male; mean age, 75 ± 10 years old) were enrolled in a prospective, nonrandomized single-center study using manufactured F-BEVAR (November 2013-March 2015). Stent design was based on supraceliac sealing zone in all patients with ≥ four vessels in 111 (89%). Follow-up included clinical examination, laboratory studies, duplex ultrasound, and computed tomography imaging at discharge, 1 month, 6 months, and yearly. End points adjudicated by independent clinical event committee included mortality, major adverse events (any mortality, myocardial infarction, stroke, paraplegia, acute kidney injury, respiratory failure, bowel ischemia, blood loss >1 L), freedom from reintervention, and branch-related instability (occlusion, stenosis, endoleak or disconnection requiring reintervention), target vessel patency, sac aneurysm enlargement, and aneurysm rupture.

RESULTS

There were 47 pararenal, 42 type IV, and 38 type I-III TAAAs with mean diameter of 59 ± 17 mm. A total of 496 renal-mesenteric arteries were incorporated by 352 fenestrations, 125 directional branches, and 19 celiac scallops, with a mean of 3.9 ± 0.5 vessels per patient. Technical success of target vessel incorporation was 99.6% (n = 493/496). There were no 30-day or in-hospital deaths, dialysis, ruptures or conversions to open surgical repair. Major adverse events occurred in 27 patients (21%). Paraplegia occurred in two patients (one type IV, one type II TAAAs). Follow-up was >30 days in all patients, >6 months in 79, and >12 months in 34. No patients were lost to follow-up. After a mean follow-up of 9.2 ± 7 months, 23 patients (18%) had reinterventions (15 aortic, 8 nonaortic), 4 renal artery stents were occluded, five patients had type Ia or III endoleaks, and none had aneurysm sac enlargement. Primary and secondary target vessel patency was 96% ± 1% and 98% ± 0.7% at 1 year. Freedom from any branch instability and any reintervention was 93% ± 2% and 93% ± 2% at 1 year, respectively. Patient survival was 96% ± 2% at 1 year for the entire cohort.

CONCLUSIONS

Endovascular repair of pararenal aortic aneurysms and TAAAs, using manufactured F-BEVAR with supraceliac sealing zones, is safe and efficacious. Long-term follow-up is needed to assess the impact of four-vessel designs on device-related complications and progression of aortic disease.

Management of Abdominal Aortic Aneurysm: A Decade of Progress

Since the world was first introduced to the concept of endovascular aneurysm repair by Parodi's landmark procedures in 1990, stent-grafts have assumed a prominent role in the management of abdominal aortic aneurysm. Most modern systems are trackable, accurate, and secure. The resulting endovascular procedure is safe, durable, effective, and versatile. Perhaps the most significant increment in the applicability of the endovascular technique was achieved by the development of bifurcated stent-grafts, which dispensed with inadequate distal aortic implantation sites. Additional branches and fenestrations now permit endovascular repair in cases of thoracoabdominal, pararenal, juxtarenal, and bilateral iliac aneurysms. These advances in device performance have been accompanied by a rapid dissemination of necessary skills, leading to the development of a new superspecialty of vascular therapy, with elements of vascular surgery, interventional radiology, and interventional cardiology.

Application of physician-modified fenestrated stent graft in urgent endovascular repair of abdominal aortic aneurysm with hostile neck anatomy: Case report

BACKGROUND

This study aimed to evaluate the feasibility and effectiveness of the Gore Excluder aortic stent graft (WL Gore & Associates, Inc., Flagstaff, AZ) using the C3 Delivery System after physician modification of fenestration for the urgent treatment of patients with abdominal aortic aneurysm showing hostile neck anatomy.

CASE SUMMARY

Three urgent cases of abdominal aortic aneurysm with hostile neck anatomy symptom with abdominal pain were reported. The same fenestration method was applied to align the target superior mesenteric artery and bilateral renal arteries with 1 scallop and 2 fenestrations, followed by the reconstruction of the target artery using a bare-metal stent or stent graft. Balloon-assisted positioning and image fusion technology were intraoperatively applied to assist the accurate release of the stent graft body. The follow-up periods for all cases exceeded 6 months, showing smooth circulation in the target arteries with no endoleaks.

CONCLUSION

In the absence of other available treatment methods, it is feasible to use a stent graft with physician-modified fenestration for the urgent endovascular repair of abdominal aortic aneurysm with hostile neck anatomy. However, this procedure's long-term efficacy needs to be further investigated.

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.

Comparison of the Fixation Strength of Standard and Fenestrated Stent-Grafts for Endovascular Abdominal Aortic Aneurysm Repair

Purpose:

To determine whether fenestrated stent-grafts provide better stability to resist migration than standard non-fenestrated stent-grafts.

Methods:

Truncated fenestrated stent-grafts with a single fenestration were deployed in bovine aortic segments with a side branch. Balloon-expandable stents were then delivered into the branches. Similarly, standard stent-grafts of the same dimensions were deployed for comparison. The aorta was pressurized to achieve stent-graft oversizing of 5%, 10%, or 20%. The force required to cause distal migration was recorded by a digital force gauge attached to the stent-graft.

Results:

Displacement of the stent-grafts occurred in 2 distinct phases: an initial yield during which the barbs embedded in the aortic wall and a final displacement leading to significant migration and dislodgement of the device. The displacement force that initiated each phase was dependent upon the degree of oversizing of the stent-graft relative to the aortic diameter. For 5%, 10%, and 20% oversizing, the mean displacement forces in the initial displacement phase were 3.39±0.37, 4.32±0.63, and 7.69±1.18 N, respectively, in non-fenestrated grafts and 10.48±1.23, 11.45±1.48, 12.12±1.42 N in fenestrated grafts. The displacement forces in the final displacement phase were 8.10±0.92, 10.76±1.74, and 16.82±0.92 N for non-fenestrated and 22.56±1.60, 28.24±1.56, and 33.01±1.75 N for fenestrated stent-grafts. The differences in displacement forces between standard and fenestrated stent-grafts were significant for both phases (p<0.001) at all oversizing levels.

Conclusion:

Improvement in fixation strength was noted with increasing stent-graft oversizing of up to 20%. Fenestrated stent-grafts offer higher ultimate fixation compared to standard devices. However, the ultimate fixation strength was not recruited until an initial phase of short migration occurred as the barbs engaged. While this movement is inconsequential with standard stent-grafts, it has the potential to crush the stents placed into aortic side branches with fenestrated endografts.

Retrograde Fenestration of Endoluminal Grafts from Target Vessels: Feasibility, Technique, and Potential Usage

Purpose:

To report initial experiments involving a new method for percutaneous intraprocedural stent-graft fenestration from the target vessel.

Technique:

In bench and canine models, the fabric of an implanted Zenith endograft was punctured easily using the stiff end of a coronary 0.014-inch guidewire delivered through the target vessel (e.g., renal or iliac artery). A 20-G cutting needle was passed over the coronary wire to enlarge the puncture site, followed by a cutting balloon to create a fenestration that was of sufficient size to allow deployment of a stent.

Conclusions:

In vivo endograft fenestration of a Zenith endograft is feasible. In addition to providing a percutaneous means of intentionally fenestrating a stent-graft from the artery to be perfused, the technique has potential application as a bailout maneuver after inadvertent side branch occlusion. Although the time to achieve successful fenestration in the experimental model was long, refinement may achieve performance times adequate to maintain viability of the end organ.

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.

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).

Endovascular treatment of abdominal aortic aneurysms

Patients with abdominal aortic aneurysms (AAAs) are usually treated with endovascular aneurysm repair (EVAR), which has become the standard of care in many hospitals for patients with suitable anatomy. Clinical evidence indicates that EVAR is associated with superior perioperative outcomes and similar long-term survival compared with open repair. Since the randomized, controlled trials that provided this evidence were conducted, however, the stent graft technology for infrarenal AAA has been further developed. Improvements include profile downsizing, optimization of sealing and fixation, and the use of low porosity fabrics. In addition, imaging techniques have improved, enabling better preoperative planning, stent graft placement, and postoperative surveillance. Also in the past few years, fenestrated and branched stent grafts have increasingly been used to manage anatomically challenging aneurysms, and experiments with off-label use of stent grafts have been performed to treat patients deemed unfit or unsuitable for other treatment strategies. Overall, the indications for endovascular management of AAA are expanding to include increasingly complex and anatomically challenging aneurysms. Ongoing studies and optimization of imaging, in addition to technological refinement of stent grafts, will hopefully continue to broaden the utilization of EVAR.