Benefits and Role of Carbon Dioxide Angiography in Case of Misalignment Between Fenestration and Target Vessel During Fenestrated Endovascular Aneurysm Repair.

PURPOSE: To report the benefits and the role of carbon dioxide (CO2) angiography in case of misalignment between fenestration and target vessel during fenestrated endovascular aneurysm repair (F-EVAR). TECHNIQUE: During F-EVAR, misalignment between fenestration and target vessel is a potentially catastrophic complication. In 2 patients, we experienced that one of the target vessels were not visible during standard angiography in different projections after positioning a fenestrated graft and even after cannulation of the corresponding fenestration. In both cases, the graft was sealed to the aortic wall but not in the predictable position. Consequently, acute occlusion of the target vessel was hypothesized. However, CO2 angiography was useful to evaluate patency of the target vessel clarifying the relative position of the fenestration versus the target vessel. Rescue maneuvers were feasible under the guidance of CO2 angiography in order to obtain the cannulation of both renal arteries. In both cases, the procedure was successfully accomplished. CONCLUSION: In case of misalignment of a fenestration during F-EVAR and non-visualization of the target vessel with standard angiography, CO2 angiography could have the unique and complementary role of clarifying the patency and position of the target vessel. In addition, CO2 could guide the rescue maneuvers.

Health care costs of endovascular compared with open thoracoabdominal aortic aneurysm repair.

OBJECTIVE: To compare 1-year health care costs between endovascular and open thoracoabdominal aortic aneurysm (TAAA). METHODS: Population-based administrative health databases were used to capture TAAA repairs performed in Ontario, Canada, between January 2006 and February 2017. All health care costs incurred by the Ministry of Health from a single-payer universal health care system were included. Costs of the aortic endografts and ancillary devices for the index procedure were estimated as C$44,000 per endovascular case vs C$1000 for open cases, based on previous reports. Costs (2017 Canadian dollars) were calculated in phases (1, 1-3, 3-6, and 6-12 months from surgery) with censoring for death. For each phase, propensity score matching of endovascular and open cases based on preoperative patient and hospital characteristics was used. The association between preoperative characteristics (including repair approach) and the first month postprocedure cost was characterized through multivariable analysis. RESULTS: Overall 664 TAAA repairs were identified (open, n = 361 [54.5%] and endovascular, n = 303 [45.6%]). At 1 month, the median cost was higher for endovascular TAAA repair in the prematching cohort (C$64,892 vs C$36,647; P < .01). Similarly, in 241 well-balanced endovascular/open patient pairs after propensity score matching, the median health care costs were higher in endovascular TAAA cases during the first month (C$62,802 vs C$33,605; P < .01). The 1- to 3-month median cost was not statistically different between endovascular and open TAAA cases either before matching (C$2781 vs C$2618; P = .71) or after matching (C$2762 vs C$2092; P = .58). Likewise, in the 3- to 6-month and 6- to 12-month postprocedure intervals, there were no significant differences in the median health care costs between groups. On multivariable analysis, older age (5-year increments) (relative change [RC] in mean cost, 1.05; 95% confidence interval [CI], 1.04-1.06; P = .01), urgent procedures (RC, 1.29; 95% CI, 1.10-1.52; P < .01), and history of stroke (RC, 1.34; 95% CI, 1.00-1.78; P = .05) were associated with higher costs in the first postoperative month, whereas open relative to endovascular TAAA repair was associated with a decreased 1-month cost (RC, 0.65; 95% CI, 0.56-0.74; P < .01). CONCLUSIONS: TAAA repair is expensive regardless of technique. Compared with open TAAA repair, endovascular repair was associated with a higher early cost, owing to the upfront cost of the endograft and aortic ancillary devices. There was no difference in cost from 1 to 12 months after repair. A decrease in the cost of endovascular devices might allow equivalent costs between endovascular and open TAAA repair.

Quantification of suprarenal aortic neck dilation after fenestrated endovascular aneurysm repair.

OBJECTIVE: Suprarenal aortic neck dilation (AND) after fenestrated endovascular aneurysm repair (FEVAR) with commercially available devices has not yet been well characterized. The aim of this study was to measure diameter changes in the supravisceral aorta after FEVAR. METHODS: This is a single-center retrospective review involving patients with juxtarenal aneurysms treated with Cook ZFEN devices (Cook Medical, Bloomington, Ind). Patients with at least 1 year of cross-sectional radiologic follow-up were included. AND was defined as ≥3 mm at any measured location. Aortic diameter, defined as the average outer to outer diameter on three-dimensional centerline imaging, was measured at seven locations along the length of the ZFEN device from the proximal fixation struts to the bottom of the second seal stent. The first postoperative CT scan (≤1 month) served as a baseline from which subsequent measurements at annual intervals were compared. RESULTS: A total of 43 patients who underwent FEVAR from 2012 to 2018 met inclusion criteria, with a total of 119 target vessels (83 renal stents, 41 superior mesenteric artery scallops or large fenestrations). Mean follow-up time was 30.3 months. Any AND was found to occur in 32 (74.4%) patients. Aortic diameter dilation at latest follow-up was found to occur at all measured locations from the top of the fixation struts (1.9 ± 2.4 mm; P < .0001) to the middle of the second seal stent (1.3 ± 3.8 mm; P < .01). Diameter growth was most pronounced in the middle of the first seal stent, with mean AND of 3.6 ± 3.2 mm. At this location, the aorta experienced nearly linear annual growth of 0.99 mm (95% confidence interval, 0.7-1.28 mm) per year. Increasing device oversizing relative to the native visceral aorta was the strongest predictor of postoperative neck diameter growth (1.34 mm per 10% increase in oversizing; P = .02), whereas increasing proximal seal length was protective of growth (-1.82 mm per 10-mm increase in seal length; P = .016). Proximal seal lengths ≥3 cm were associated with less neck dilation compared with <3 cm (2.6 mm vs 4.9 mm; P = .022). Type IA endoleak in this cohort was rare (n = 1) and not associated with AND (P = .256). CONCLUSIONS: Dilation of the suprarenal aorta is a common finding in midterm follow-up after FEVAR and not associated with proximal endoleak. Aggressive device oversizing is predictive of dilation, whereas longer seal lengths are associated with less dilation along the suprarenal seal zone. These results support the continued use of FEVAR for juxtarenal aneurysms, particularly in patients in whom ≥3 cm of healthy seal length can be obtained.

Respiratory-induced changes in renovisceral branch vessel morphology after fenestrated thoracoabdominal aneurysm repair with the BeGraft balloon-expandable covered stent.

OBJECTIVE: We evaluated the respiratory-induced changes in branch vessel geometry after thoracoabdominal fenestrated endovascular aneurysm repair (fEVAR) with the Bentley BeGraft graft (Innomed GmbH, Hechingen, Germany) as the covered bridging stent. METHODS: Patients treated with fEVAR for thoracoabdominal aortic aneurysms with a custom-made Zenith fenestrated endograft (Cook Medical Europe Ltd, Limerick, Ireland) and Bentley BeGraft peripheral stents were prospectively recruited. Using SimVascular software (Open-Source Medical Software Corp, San Diego, CA), the pre- and postoperative aortic and branch contours were segmented from computed tomography angiograms performed during inspiratory and expiratory breath-holds. The centerlines were extracted from the lumen contours, from which the branch take-off angles, distal stent angles, and peak branch curvature changes were computed. Paired, two-tailed t tests were performed to compare the pre- and postoperative deformations. RESULTS: Renovisceral vessel geometry was evaluated in 12 patients undergoing fEVAR with a total of 46 target vessels (10 celiac arteries, 12 superior mesenteric arteries [SMAs], 24 renal arteries). Implantation of BeGraft bridging stents was associated with a significant reduction in respiration-induced changes in vessel branch angulation (Δ5.3° ± 3.9° vs Δ12.0° ± 8.3° [postoperative vs preoperative]; P = .001) and mean curvature (0.72 ± 0.22 cm-1 vs 0.53 ± 0.18 cm-1) in the renal arteries, without significant changes in the celiac arteries or SMAs. No significant difference was found in end-stent angle motion in the renal arteries (P = .77), celiac arteries (P = .34), or SMAs (P = .55). The maximum local vessel curvature change decreased after fEVAR in the SMAs (Δ0.28 cm-1 vs Δ0.47 cm-1; P = .04) but was unchanged in the celiac (P = .61) and renal (P = .51) arteries. CONCLUSIONS: Implantation of the BeGraft as a bridging stent in fEVAR was associated with decreased respiratory-induced deformation in the renal branch take-off angulation and mean renal artery curvature, with reduced maximum curvature bending in the SMA compared with the preoperative anatomy. However, the BeGraft allowed for celiac and renal artery bending similar to that in the native preoperative state. These findings suggest that the use of BeGraft peripheral stents with fEVAR will closely mimic the native arterial branch geometry and vessel conformability caused by relatively aggressive respiratory motion.

Early outcomes of Jotec inner-branched endografts in complex endovascular aortic aneurysm repair.

OBJECTIVE: Complex aortic endografts have evolved to include inner branches to overcome specific challenges with existing technologies. We have reported the early outcomes of endovascular aortic aneurysm repair (EVAR) using a Jotec inner branched endograft (iBEVAR). METHODS: All patients who had undergone complex EVARs using extra-design engineering iBEVAR (Jotec GmbH, Hechingen, Germany) from 2018 to 2020 at a single center were reviewed. The patient demographics, cardiovascular risk factors, anatomic features of the aneurysms, and target vessels were recorded. The reasons for using inner branches instead of fenestrated and standard branched endografts and the procedural details, outcomes, and reintervention during follow-up were examined. RESULTS: A total of 110 patients were treated with branched and fenestrated endografts during the study period, of whom 18 patients had had a patient-specific custom-made iBEVAR endograft with downward inner branches. The technical success rate was 100%. A total of 68 target vessels were cannulated, and bridging stent-grafts were placed successfully in all. The reasons for choosing the iBEVAR design included unfavorable target vessel trajectory for fenestrated repair (n = 15), excessive infrarenal aortic angulation and/or adverse iliac access vessels for fenestrated repair (n = 11), the presence of a narrow aortic lumen (n = 14), and/or to reduce aortic coverage compared with that with standard outer branched repair (n = 14). We also used iBEVAR to treat type Ia endoleaks after failed EVAR with a short main body (n = 5). The median contrast volume used was 120 mL (range, 48-200 mL), with a median fluoroscopy screening time of 66 minutes (range, 35-136 minutes) and a median dose-area product of 17,832 dGy∙cm2 (range, 8260-55,070 dGycm2). No 30-day mortality and no major complications occurred. One early intervention was required for a suspected type Ib endoleak from an iliac limb and one late intervention for in-stent stenosis in a renal bridging stent-graft. One patient had died of non-aortic-related causes at 3 months. All other patients continued with follow-up with their aneurysms excluded, patent target vessels, and no type I or III endoleak identified at a median follow-up of 12 months (range, 1-26 months). CONCLUSIONS: The use of Jotec extra-design engineering endografts incorporating downward inner branches resulted in satisfactory early outcomes with a low reintervention rate. The technology has the potential to be a useful addition to our armamentarium for treating complex aortic endografts; however, long-term outcomes data are needed.

Effect of thoracoabdominal aortic aneurysm extent on outcomes in patients undergoing fenestrated/branched endovascular aneurysm repair.

OBJECTIVE: The outcomes after open repair of thoracoabdominal aneurysms (TAAAs) have been definitively demonstrated to worsen as the TAAA extent increases. However, the effect of TAAA extent on fenestrated/branched endovascular aneurysm repair (F/BEVAR) outcomes is unclear. We investigated the differences in outcomes of F/BEVAR according to the TAAA extent. METHODS: We reviewed a single-institution, prospectively maintained database of all F/BEVAR procedures performed in an institutional review board-approved registry and/or physician-sponsored Food and Drug Administration investigational device exemption trial (trial no. G130210). The patients were stratified into two groups: group 1, extensive (extent 1-3) TAAAs; and group 2, nonextensive (juxtarenal, pararenal, and extent 4-5) TAAAs. The perioperative outcomes were compared using the χ2 test. Kaplan-Meier analysis of 3-year survival, target artery patency, reintervention, type I or III endoleak, and branch instability (type Ic or III endoleak, loss of branch patency, target vessel stenosis >50%) was performed. Cox proportional hazards modeling was used to assess the independent effect of extensive TAAA on 1-year mortality. RESULTS: During the study period, 299 F/BEVAR procedures were performed for 87 extensive TAAAs (29%) and 212 nonextensive TAAAs (71%). Most repairs had used company-manufactured, custom-made devices (n = 241; 81%). Between the two groups, no perioperative differences were observed in myocardial infarction, stroke, acute kidney injury, dialysis, target artery occlusion, access site complication, or type I or III endoleak (P > .05 for all). The incidence of perioperative paraparesis was greater in the extensive TAAA group (8.1% vs 0.5%; P = .001). However, the incidence of long-term paralysis was equivalent (2.3% vs 0.5%; P = .20), with nearly all patients with paraparesis regaining ambulatory function. On Kaplan-Meier analysis, no differences in survival, target artery patency, or freedom from reintervention were observed at 3 years (P > .05 for all). Freedom from type I or III endoleak (P < .01) and freedom from branch instability (P < .01) were significantly worse in the extensive TAAA group. Cox proportional hazards modeling demonstrated that F/BEVAR for extensive TAAA was not associated with 1-year mortality (hazard ratio, 1.71; 95% confidence interval, 0.91-3.52; P = .13). CONCLUSIONS: Unlike open TAAA repair, the F/BEVAR outcomes were similar for extensive and nonextensive TAAAs. The differences in perioperative paraparesis, branch instability, and type I or III endoleak likely resulted from the increasing length of aortic coverage and number of target arteries involved. These findings suggest that high-volume centers performing F/BEVAR should expect comparable outcomes for extensive and nonextensive TAAA repair.

"Awake" Spinal Cord Monitoring Under Local Anesthesia and Conscious Sedation in Fenestrated and Branched Endovascular Aortic Repair.

INTRODUCTION: Endovascular repair of thoracoabdominal aortic aneurysms carries a risk of spinal cord ischemia, the causes of which remain uncertain. We hypothesized that local anesthesia (LA) with conscious sedation could abrogate the potential suppressive cardiovascular effects of general anesthesia (GA) and facilitate intraoperative monitoring of neurological function. Here, we examine the feasibility of this technique during fenestrated (FEVAR) or branched endovascular aortic repair (BEVAR). MATERIALS AND METHODS: Consecutive patients undergoing FEVAR or BEVAR under LA and conscious sedation by a team at a single center were analyzed. Patients received conscious sedation using intravenous remifentanil and propofol infusions in conjunction with a local anesthetic agent. No patient had a prophylactic spinal drain inserted. Outcome measures included conversion to GA, need for vasopressors and/or spinal drainage, length of stay, complications, and patient survival. RESULTS: A total of 44 patients underwent FEVAR or BEVAR under LA and conscious sedation. The cohort included thoracoabdominal aortic aneurysms (n=41) and pararenal aneurysms treated with endografts covering the supraceliac segment (n=3). Four patients (9%) required conversion to GA at a median operative duration of 198 minutes (range 97-495 minutes). Vasopressors were required intraoperatively in 3 of the cases that were converted to GA. No patient developed spinal cord ischemia and none had insertion of a spinal drain. The median hospital length of stay was 4 days (range 2-41 days). Postoperative delirium and hospital-acquired pneumonia was seen in 7% of patients. All patients survived to 30 days, with 95% alive at a median follow-up of 15 months (range 3-26 months). CONCLUSION: LA and conscious sedation is a feasible anesthetic technique for the endovascular repair of thoracoabdominal aortic aneurysms.

Increased ischemic complications in fenestrated and branched endovascular abdominal aortic repair compared with standard endovascular aortic repair.

OBJECTIVE: Ischemic complications (including in the lower extremity, visceral, spinal, and pelvic territories) following standard endovascular aortic repair (EVAR) are well recognized but fortunately uncommon. The incidence of such complications following fenestrated and branched aortic repair (F/BEVAR) has not been well defined in the literature. The objective of this study was to compare the incidence of ischemic complications between EVAR and F/BEVAR and to elucidate potential risk factors for these complications. METHODS: We identified all patients who underwent EVAR from 2003 to 2017 or F/BEVAR from 2012 to 2017 in the national Vascular Quality Initiative database. We assessed differences in perioperative ischemic outcomes with methods including logistic regression and inverse probability of treatment propensity score weighting, using a composite end point of lower extremity ischemia, intestinal ischemia, stroke, or new dialysis as the primary end point. RESULTS: The data comprised 35,379 EVAR patients and 3374 F/BEVAR patients. F/BEVAR patients were more likely to be female, have had previous aneurysm repairs, and be deemed unfit for open aneurysm repair; they were less likely to have ruptured aneurysms; and they had higher estimated blood losses, contrast volumes, and fluoroscopy and procedure times. The incidence of any ischemic event (7.7% vs 2.2%) as well as the incidences of the component end points of lower extremity ischemia (2.3% vs 1.0%), intestinal ischemia (2.7% vs 0.7%), stroke (1.5% vs 0.3%), and new hemodialysis (3.1% vs 0.4%) were all significantly increased (all P < .001) in F/BEVAR compared with standard EVAR. After propensity adjustment, F/BEVAR conferred increased odds of any ischemic complication (1.8), intestinal ischemia (2.0), lower extremity ischemia (1.3), new hemodialysis (10.2), and stroke (2.3). CONCLUSIONS: Rates of lower extremity ischemia, intestinal ischemia, new dialysis, and stroke each range from 0% to 1% for standard EVAR and 1% to 3% for F/BEVAR. The incidence of perioperative ischemic complications following F/BEVAR is significantly increased compared to EVAR. The real-world data in this study should help guide decision-making for surgeons and patients as well as serve as one metric for progress in device and technique development. Improvements in ischemic complications may come from continued technology development such as smaller sheaths, improved imaging to decrease procedure time and contrast volume, embolic protection, and increased operator skill with wire and catheter manipulation.

A reliable method for renal volume measurement and its application in fenestrated endovascular aneurysm repair.

OBJECTIVE: Renal volume has been shown to correlate with renal function. Renal volume and renal function both decline steadily in the sixth decade of life and beyond. We sought to assess (1) the inter-rater reliability for manually measuring renal volume using computed tomography and (2) change in renal volume over time as it relates to renal function in fenestrated endovascular aortic aneurysm repair (FEVAR). METHODS: This study was conducted as part of a physician-sponsored investigational new device (#NCT01538056). First, 30 consecutive kidneys of preoperative FEVAR patients were independently measured by two raters using manual segmentation and three-dimensional modeling software. Renal volumes were calculated and compared. Intraclass correlation was calculated between the two observers. Second, renal volumes were then recorded for 85 patients undergoing FEVAR with follow-up out to 5 years. Demographic data, comorbidities, creatinine, glomerular filtration rate (GFR), renal artery stenosis or occlusion, and bilateral renal volume measurements were analyzed. Multivariate analysis was performed to delineate association of these variables with total renal volume (TRV). RESULTS: The intraclass correlation coefficient for our renal volume measurements was 0.97 (95% confidence interval, 0.81-0.99), indicating excellent correlation. Renal volume was strongly correlated with GFR. Our multivariate analysis model predicts a 17.9 mL/min increase in GFR with each 20% increase in TRV. After adjustment for all other known correlates of renal function, renal volume remained as the only significant predictor of renal function. CONCLUSIONS: Renal volume can be measured with high reliability using manual segmentation and computed tomography scans. In our baseline analysis, TRV was strongly correlated with renal function. These findings support the potential for renal volume as a surrogate for renal function.

Two-year evaluation of fenestrated and parallel branch endografts for the treatment of juxtarenal, suprarenal, and thoracoabdominal aneurysms at a single institution.

OBJECTIVE: Despite numerous recent pivotal and small-scale trials, real-world endovascular management of juxtarenal aneurysms (JRA), suprarenal aneurysms (SRA), and thoracoabdominal aortic aneurysms (TAAA) remains challenging without consensus best practices. This study evaluated the mortality, graft patency, renal function, complication, and reintervention rates for fenestrated and parallel endografts in complex aortic aneurysms repairs. METHODS: This retrospective review of consecutive included patients with JRA, SRA, or TAAA who underwent complex endovascular repair from August 2014 to March 2017 at one high-volume institution. Treatment modality was a single surgeon decision based on patients anatomy and the urgency of the repair. Patient demographics, hospital course, and follow-up visits inclusive of imaging were analyzed. Ruptured aneurysms were excluded. Survival rates and outcomes were determined using the Kaplan-Meier method with log-rank tests. RESULTS: Seventy complex endovascular aortic repairs were performed; 38 patients with TAAA were treated with snorkel/sandwich parallel endografts (21 celiac, 28 superior mesenteric arteries, 58 renal arteries) and 32 patients with JRA/SRA were treated by fenestrated endovascular aneurysm repair (FEVAR) with 94 total fenestrations (2 celiac, 30 SMA, 62 renal). The mean patient age was 74.8 ± 10.0 years. Sixty percent were male, and the mean aortic aneurysm diameter was 6.0 ± 1.4 cm. Perioperative mortality was 3.1% (1/32) for FEVAR compared with 2.6% (1/38) for parallel endografts (P = .9). All-cause reintervention rates were 15.6% in FEVAR (5/32) vs 23.6% with parallel endografts (9/38; P = .4). Branch reintervention rates per each branch endograft were 4.3% for FEVAR (4/94; 2 renal stent occlusions, 1 colonic ischemia without technical issue found on reintervention, 1 perinephric hematoma) vs 3.7% for parallel endografts (4/107; 2 renal and 1 celiac stent thromboses, and 1 renal stent kink; P = .41). The endograft branch thrombosis rate was 2.1% in FEVAR (2/94) vs 2.7% in parallel endografts (3/109; P = .77). Reinterventions owing to endoleaks were performed in five patients (2 type I, 2 type III, and 1 gutter endoleak; 13.1%) with parallel grafts vs no endoleak reinterventions in FEVAR. The overall survival and freedom from aneurysm-related mortality at 24 months was 78% and 96.9% in FEVAR vs 73% and 93.4% for parallel endografts (P = .8 and P = .6). The median follow-up was 12 months (range, 1-32 months). CONCLUSIONS: Parallel and fenestrated endografts have acceptable and comparable mortality and patency rates in endovascular treatment of JRA, SRA, and TAAA. This study reaffirms that parallel endografts are a safe and viable alternative to fenestrated devices for complex aortic aneurysmal disease despite often treating more urgent patients and more complicated anatomy unable to be treated with FEVAR.

Long-term durability of a physician-modified endovascular graft.

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

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.

Select type I and type III endoleaks at the completion of fenestrated endovascular aneurysm repair resolve spontaneously.

OBJECTIVE: The Society for Vascular Surgery reporting standards for endovascular aneurysm repair (EVAR) consider the presence of a type I or type III endoleak a technical failure. However, the nature and implications of these endoleaks in fenestrated EVAR (FEVAR) are not well understood. METHODS: We performed a single-center retrospective review of 53 patients who underwent FEVAR with the Zenith Fenestrated AAA Endovascular Graft (Cook Medical, Bloomington, Ind) from 2013 to 2018. We excluded one patient without contrast-enhanced postoperative imaging who was lost to follow-up after discharge. Small, slow, type I and type III endoleaks on completion angiography were routinely observed. We identified patients with completion type I or type III endoleaks by angiography review and characterized endoleak type, location, and rate of resolution on initial postoperative imaging. RESULTS: Fifty-two patients were included; mean age was 75 ± 8 years, 75% were male, and 91% were white. Of 146 visceral vessels (100 renal arteries and 46 superior mesenteric arteries), 145 (99%) were preserved with 103 fenestrations and 43 scallops; 102 (70%) target vessels were stented. After implantation of all device components, 31 patients (60%) had evidence of type I or type III endoleak. Twelve patients (39%) underwent further intervention at the index procedure, and three endoleaks resolved completely. Twenty-eight patients (54%) had a type I or type III endoleak on completion angiography. There were no differences between patients with and without completion endoleaks in baseline demographics, graft design, neck anatomy, or proportion of cases performed within the instructions for use of the device. Perioperative mortality was 1.9%. On initial postoperative imaging, 27 of 28 (96%) endoleaks resolved spontaneously. One small, persistent type IA or type III endoleak was identified on postoperative day 27 and was observed. This endoleak had resolved completely on computed tomography angiography 6 months postoperatively. In patients without a completion endoleak, one type IA endoleak secondary to graft infolding was discovered on postoperative imaging and was successfully treated with placement of endoanchors and Palmaz stent. Median follow-up was 269 days. No additional type I or type III endoleaks were identified in any patient for the duration of follow-up. CONCLUSIONS: Whereas completion type I and type III endoleaks are common after FEVAR with the ZFEN device, nearly all of these endoleaks resolve spontaneously by the initial postoperative imaging. These results suggest that select completion endoleaks after FEVAR with the ZFEN device do not require intervention at the index procedure.

Patient-specific computational flow simulation reveals significant differences in paravisceral aortic hemodynamics between fenestrated and branched endovascular aneurysm repair.

Background: Endovascular aneurysm repair with four-vessel fenestrated endovascular aneurysm repair (fEVAR) or branched endovascular aneurysm repair (bEVAR) currently represent the forefront of minimally invasive complex aortic aneurysm repair. This study sought to use patient-specific computational flow simulation (CFS) to assess differences in postoperative hemodynamic effects associated with fEVAR vs bEVAR. Methods: Patients from two institutions who underwent four-vessel fEVAR with the Cook Zenith Fenestrated platform and bEVAR with the Jotec E-xtra Design platform were retrospectively selected. Patients in both cohorts were treated for paravisceral and extent II, II, and V thoracoabdominal aortic aneurysms. Three-dimensional finite element volume meshes were created from preoperative and postoperative computed tomography scans. Boundary conditions were adjusted for body surface area, heart rate, and blood pressure. Pulsatile flow simulations were performed with equivalent boundary conditions between preoperative and postoperative states. Postoperative changes in hemodynamic parameters were compared between the fEVAR and bEVAR groups. Results: Patient-specific CFS was performed on 20 patients (10 bEVAR, 10 fEVAR) with a total of 80 target vessels (40 renal, 20 celiac, 20 superior mesenteric artery stents). bEVAR was associated with a decrease in renal artery peak flow rate (-5.2% vs +2.0%; P < .0001) and peak pressure (-3.4 vs +0.1%; P < .0001) compared with fEVAR. Almost all renal arteries treated with bEVAR had a reduction in renal artery perfusion (n = 19 [95%]), compared with 35% (n = 7) treated with fEVAR. There were no significant differences in celiac or superior mesenteric artery perfusion metrics (P = .10-.27) between groups. Time-averaged wall shear stress in the paravisceral aorta and branches also varied significantly depending on endograft configuration, with bEVAR associated with large postoperative increases in renal artery (+47.5 vs +13.5%; P = .002) and aortic time-averaged wall shear stress (+200.1% vs -31.3%; P = .001) compared with fEVAR. Streamline analysis revealed areas of hemodynamic abnormalities associated with branched renal grafts which adopt a U-shaped geometry, which may explain the observed differences in postoperative changes in renal perfusion between bEVAR and fEVAR. Conclusions: bEVAR may be associated with subtle decreases in renal perfusion and a large increase in aortic wall shear stress compared with fEVAR. CFS is a novel tool for quantifying and visualizing the unique patient-specific hemodynamic effect of different complex EVAR strategies. Clinical Relevance: This study used patient-specific CFS to compare postoperative hemodynamic effects of four-vessel fenestrated endovascular aneurysm repair (fEVAR) and branched endovascular aneurysm repair (bEVAR) in patients with complex aortic aneurysms. The findings indicate that bEVAR may result in subtle reductions in renal artery perfusion and a significant increase in aortic wall shear stress compared with fEVAR. These differences are clinically relevant, providing insights for clinicians choosing between these approaches. Understanding the patient-specific hemodynamic effects of complex EVAR strategies, as revealed by CFS, can aid in future personalized treatment decisions, and potentially reduce postoperative complications in aortic aneurysm repair.

Report of a semi-branched stent-graft to treat a type 1a endoleak after failed EVAR.

BACKGROUND: Endovascular techniques are advancing with the change of treatment paradigm for abdominal aortic aneurysms. Fenestrated EVAR (fEVAR) and branched EVAR (bEVAR) are used for complex aortic aneurysm repair. Both fEVAR and bEVAR have their own advantages and disadvantages. Semi-branches are a new feature that attempt to combine the advantages of both fEVAR and bEVAR. TECHNIQUE: We describe the use of a 4-vessel semi-branched EVAR in a failed EVAR case with a type 1a endoleak. CONCLUSION: The novel feature of semi-branches in custom-made EVAR devices in endovascular aortic treatment following failed EVAR appear to be a feasible option.

Patient-specific changes in aortic hemodynamics is associated with thrombotic risk after fenestrated endovascular aneurysm repair with large diameter endografts.

Background: The durability of fenestrated endovascular aneurysm repair (fEVAR) has been threatened by thrombotic complications. In the present study, we used patient-specific computational fluid dynamic (CFD) simulation to investigate the effect of the endograft diameter on hemodynamics after fEVAR and explore the hypothesis that diameter-dependent alterations in aortic hemodynamics can predict for thrombotic events. Methods: A single-institutional retrospective study was performed of patients who had undergone fEVAR for juxtarenal aortic aneurysms. The patients were stratified into large diameter (34-36 mm) and small diameter (24-26 mm) endograft groups. Patient-specific CFD simulations were performed using three-dimensional paravisceral aortic models created from computed tomographic images with allometrically scaled boundary conditions. Aortic time-averaged wall shear stress (TAWSS) and residence time (RT) were computed and correlated with future thrombotic complications (eg, renal stent occlusion, development of significant intraluminal graft thrombus). Results: A total of 36 patients (14 with a small endograft and 22 with a large endograft) were included in the present study. The patients treated with large endografts had experienced a higher incidence of thrombotic complications compared with small endografts (45.5% vs 7.1%; P = .016). Large endografts were associated with a lower postoperative aortic TAWSS (1.45 ± 0.76 dynes/cm2 vs 3.16 ± 1.24 dynes/cm2; P < .001) and longer aortic RT (0.78 ± 0.30 second vs 0.34 ± 0.08 second; P < .001). In the large endograft group, a reduction >0.39 dynes/cm2 in aortic TAWSS demonstrated discriminatory power for thrombotic complications (area under the receiver operating characteristic curve, 0.77). An increased aortic RT of ≥0.05 second had similar accuracy for predicting thrombotic complications (area under the receiver operating characteristic curve, 0.78). The odds of thrombotic complications were significantly higher if patients had met the hemodynamic threshold changes in aortic TAWSS (odds ratio, 7.0; 95% confidence interval, 1.1-45.9) and RT (odds ratio, 8.0; 95% confidence interval, 1.13-56.8). Conclusions: Patient-specific CFD simulation of fEVAR in juxtarenal aortic aneurysms demonstrated significant endograft diameter-dependent differences in aortic hemodynamics. A postoperative reduction in TAWSS and an increased RT correlated with future thrombotic events after large-diameter endograft implantation. Patient-specific simulation of hemodynamics provides a novel method for thrombotic risk stratification after fEVAR.

Chimney vs. Fenestrated Endovascular vs. Open Repair for Juxta/Pararenal Abdominal Aortic Aneurysms: Systematic Review and Network Meta-Analysis of the Medium-Term Results.

Introduction: This systematic review with network meta-analysis aimed at comparing the medium-term results of open surgery (OS), fenestrated endovascular repair (FEVAR), and chimney endovascular repair (ChEVAR) in patients with juxta/pararenal abdominal aortic aneurysms (JAAAs/PAAAs). Materials and methods: MEDLINE, SCOPUS, and Web of Science were searched from inception date to 1st July 2022. Any studies comparing the results of two or three treatment strategies (ChEVAR, FEVAR, or OS) on medium-term outcomes in patients with JAAAs/PAAAs were included. Primary outcomes were all-cause mortality, aortic-related reintervention, and aortic-related mortality, while secondary outcomes were visceral stent/bypass occlusion/occlusion, major adverse cardiovascular events (MACEs), new onset renal replacement therapy (RRT), total endoleaks, and type I/III endoleak. Results: FEVAR (OR = 1.53, 95%CrI 1.03-2.11) was associated with higher medium-term all-cause mortality than OS. Sensitivity analysis including only studies that analysed JAAA showed that FEVAR (OR = 1.65, 95%CrI 1.08-2.33) persisted to be associated with higher medium-term mortality than OS. Both FEVAR (OR = 8.32, 95%CrI 3.80-27.16) and ChEVAR (OR = 5.95, 95%CrI 2.23-20.18) were associated with a higher aortic-related reintervention rate than OS. No difference between different treatment options was found in terms of aortic-related mortality. FEVAR (OR = 13.13, 95%CrI 2.70-105.2) and ChEVAR (OR = 16.82, 95%CrI 2.79-176.7) were associated with a higher rate of medium-term visceral branch occlusion/stenosis compared to OS; however, there was no difference found between FEVAR and ChEVAR. Conclusions: An advantage of OS compared to FEVAR and ChEVAR after mid-term follow-up aortic-related intervention and vessel branch/bypass stenosis/occlusion was found. This suggests that younger, low-surgical-risk patients might benefit from open surgery of JAAA/PAAA as a first approach.

Exclusion of complex aortic aneurysm with chimney endovascular aortic repair is applicable in a minority of patients treated with fenestrated endografts.

OBJECTIVES: The Medtronic Endurant II stent graft has recently received Conformité Européenne (CE) approval for the use in chimney endovascular aortic repair (ChEVAR) for the treatment for juxtarenal aortic aneurysms. The aim of this study was to assess the percentage of patients treated by fenestrated endovascular repair who would have been alternatively suitable for the treatment by the CE approved Medtronic ChEVAR. METHODS: Preoperative computed tomography scans of 100 patients who underwent fenestrated endovascular aortic repair (FEVAR) between April 2013 and February 2017 were retrospectively assessed for the applicability of the ChEVAR technique according to the Medtronic instructions for use. Eligibility criteria included an aortic neck diameter of 19-30 mm, a minimum infrarenal neck length of 2 mm, a total proximal sealing zone of at least 15 mm, thrombus in the aortic neck in ˂25% of the circumference, and maximum aortic angulations of 60° in the infrarenal, 45° in the suprarenal segment and ˂45° above the superior mesenteric artery. RESULTS: According to CE-approved inclusion criteria, 19 individuals (19%) would have been eligible for ChEVAR. In 81 patients, at least 1 measure was found outside instructions for use: (i) excluding factor was detected in 26 patients, (ii) incongruous measures in 28 patients and in 27 patients, 3-5 measures were outside the instructions for use. The most frequently identified excluding factor was an insufficient infrarenal neck at ˂2 mm length (n = 63; 63%). CONCLUSIONS: Patients with juxta- or pararenal aneurysm treated by FEVAR are in 19% of the cases alternatively suitable for the treatment by ChEVAR within CE-approved instructions for use. While ChEVAR is suitable in many emergency cases, FEVAR offers a broader applicability in an elective setting.

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.