Off-the-Shelf Single-Fenestrated Endograft for Emergent Juxtarenal and Pararenal Abdominal Aortic Aneurysm.

INTRODUCTION: Endovascular solutions to emergent juxtarenal and pararenal abdominal aortic aneurysms (AAAs) are complicated. Endovascular aortic repair (EVAR) with in situ laser fenestration (ISLF) is promising but requires a period of visceral ischemia. With an off-the-shelf, single superior mesenteric artery (SMA)-fenestrated device mesenteric ischemia is avoided and renal ischemia decreased. The aim was to develop an optimized design of such an endograft suitable for >90% of juxtarenal and pararenal AAAs. METHODS: Single-center analysis on 44 consecutive preoperative CTs for previously elective fenestrated EVARs for juxtarenal and pararenal aneurysms. Anatomical characteristics were analyzed to define: (1) shortest aortic coverage above SMA fenestration to achieve ≥4 cm seal; (2) feasibility of a scallop for the celiac artery; (3) shortest distance between the SMA and lowest renal, to facilitate renal ISLF in a straight endograft; (4) distance from the lowest renal to the aortic bifurcation, to allow an overlapping zone >40 mm with a bifurcated stent graft; (5) aortic diameter in the sealing zone, for optimal proximal stent graft diameter with 10% to 30% oversizing; (6) the final design was then tested on individual level. RESULTS: (1) The stent graft needs to start 40 mm above the SMA fenestration to achieve a 4 cm sealing zone in >90% of cases. (2) A proximal sealing zone of 40 mm without a scallop covers 77% of celiac arteries. With an addition of a 20 mm deep, 20 mm wide scallop at 12:30, the stent graft still covers 27% of celiacs. This suggests that a scallop would not be practically feasible. (3) In >90% of cases, the lowest renal was <31 mm from the SMA, suggesting that the tapering should start 30 mm below the SMA. (4) The distance from the lowest renal to the aortic bifurcation ranged from 82 to 166 mm. This allows for a 20 mm tapering and 50 mm straight part in all cases. (5) The 5th and 95th percentile of the aortic diameter in the sealing zone was 22 and 31 mm, respectively. Thus, 2 different stent graft diameters (28 and 34 mm) would fit >90% of cases. (6) The final design was suitable in 91% cases. CONCLUSIONS: Two sizes of a single-fenestrated aortic stent graft without scallop cover >90% of juxtarenal and pararenal anatomies. CLINICAL IMPACT: Emergent juxta- and pararenal aortic aneurysms is a difficult clinical scenario that continuously challenges physicians. An endovascular option is in situ laser fenestrated endografts. One risk with these is the complete visceral ischemia occurring before the fenestrations are completed. An off-the-shelf single-fenestrated stent graft facilitates the treatment by removing the ischemia time for the SMA and reducing the ischemia time for the celiac and renal arteries thus decreasing the risk of visceral ischemia complications.

Urgent Juxtarenal Aortic Aneurysm Repair With Modified Off-the-shelf Endograft to Preserve Intercostal Arteries and Branch Incorporation by Transfemoral Access.

PURPOSE: To demonstrate the feasibility of the modification to preserve intercostal arteries of the t-Branch Endograft (Cook Medical, Bloomington, IN) in an urgent setting, associated with a less invasive approach for branch incorporation from percutaneous femoral access with steerable sheaths. TECHNIQUE: A 73-year-old female patient presented at our institution with intense abdominal pain. Angiotomography showed a 50-mm juxtarenal aortic aneurysm, with no signs of rupture. Urgent endovascular repair was indicated due to abdominal symptom with an off-the-shelf multi-branched endograft. To limit descending thoracic aortic coverage, we performed t-Branch modification to preserve intercostal arteries and minimize the risk of spinal cord injury, associated with a percutaneous transfemoral approach and branch incorporation with steerable sheaths to avoid the risks associated with a superior axillary or brachial access. Control angiotomography showed adequate aneurysm sac exclusion with patency of all four visceral vessels. CONCLUSION: t-Branch-modified endograft to limit aortic coverage is an alternative option in urgent cases to diminish the risk of spinal cord injury, and association of steerable sheaths with branch incorporation is leading complex aortic repairs to an even less invasive procedure. CLINICAL IMPACT: This paper highlights the possibility of performing complex endovascular aortic repair in an urgent setting with modification of an off-the-shelf multi branched endograft limiting intercostal arteries coverage, thereby diminishing the risk of spinal cord ischemia. This technical innovation provides an alternative for clinicians when treating large, rapidly expanding, or symptomatic juxtarenal, pararenal, paravisceral or type 4 thoracoabdominal aortic aneurysms that could not wait for a custom-made device and do not need extensive thoracic aortic coverage that an off-the-shelf device provides. In summary, expand the possibilities of an endovascular repair of complex aortic aneurysms.

New Preloaded System for Renal and Visceral Arteries in Fenestrated Endografting.

AIM/BACKGROUND: The New Preloaded System (NPS) for renal/visceral arteries (TVVs) is an emerging technology in fenestrated endografting (FEVAR) that allows TVVs cannulation and stenting through the same access of the endograft main body. However, only few preliminary experiences are currently available in the literature. The aim of this study is to report the outcomes of NPS-FEVAR in juxta/para-renal (J/P-AAAs) and thoracoabdominal (TAAAs) aneurysms repair. METHODS: This is a prospective (NCT05224219), single-center/observational study of patients submitted to NPS-FEVAR for J/PAAAs and TAAAs between 2019 and 2022 (July). Definitions and outcomes were evaluated according to the current SVS-reporting standard. Technical success (TS) and TS preloaded related, spinal cord ischemia (SCI), and 30-day mortality were assessed as early endpoints. Survival, freedom from reinterventions (FFRs), and freedom from TTVs-instability (FFTVVs-instability) were analyzed during follow-up. RESULTS: Among 157 F/B-EVAR cases, 74 (47%) NPS-FEVAR were planned and enrolled in the study [48 (65%) J/P-AAAs; 26 (35%) TAAAs]. The main indication for NPS-FEVAR was the presence of a hostile iliac axis (54%-73%) or the necessity of expeditious pelvic/lower-limb reperfusion for SCI prevention in TAAAs (20%-27%). Overall, 292 TVVs were accommodated by 289 fenestrations and 3 branches; 188 of 289 (65%) fenestrations were preloaded. NPS-FEVAR configuration was from "below" and "from below to above" in 28 (38%) and 46 (62%) cases, respectively. TS and TS preloaded system-related was 96% (71/74) and 99% (73/74), respectively. Target visceral vessels patency at the completion angiography was 99% (290/292). Failures were 2 renal arteries loss and 1 massive bleeding from a percutaneous closure system breakage. The latter patient developed postoperative multiorgans failure and died on the fifth postoperative day, causing only 30-day/in-hospital mortality (1.3%). One (1.3%) patient with a JAAA and preoperative bilateral occlusion of the hypogastric arteries suffered SCI. The median follow-up was 14 (IQR: 8) months. The estimated 3-year survival was 91% with no aneurysm-related mortality during follow-up. The estimated 3-year FFR and FFTVVs-instability were 85 and 92%, respectively. CONCLUSION: New preloaded system FEVAR is a safe and effective option in the treatment of J/PAAAs and TAAAs in the presence of hostile iliac access or to guarantee an expeditious pelvic/lower limb reperfusion, leading to satisfactory results in terms of TS, early and mid-term clinical outcomes. CLINICAL IMPACT: New preloaded system for fenestrated and branched endografting allows to increase the feasibility of the advanced endovascular aortic repair in challenging iliac access, thoracoabdominal aneurysm repair and reduce difficulties in target visceral vessels cannulation.

Predicting Features of Visceral Stent Failure in Fenestrated Endovascular Aortic Aneurysm Repair.

PURPOSE: Visceral stents in fenestrated endovascular aortic repair (FEVAR) have a significant risk of complications and carry a considerable burden of reinterventions. The aim of this study is to identify preoperative and intraoperative predictors of visceral stent failure. MATERIALS: A retrospective review of 75 consecutive FEVARs in a single center from 2013 to 2021 was undertaken. Data on mortality, stent failure, and reintervention pertaining to 226 visceral stents were collected. METHODS: Anatomical features including aortic neck angulation, aneurysm diameter, and angulation of target viscerals were obtained from preoperative computed tomography (CT) scans. Stent oversizing and intraprocedural complications were recorded. Postoperative CT scans were analyzed to determine the length of cover of target vessels. RESULTS: Only bridging stents through fenestrations to visceral vessels were considered; 28 (37%) cases had 4 visceral stents, 24 (32%) had 3, 19 (25%) had 2, 4 (5%) had 1. Thirty day mortality was 8%, a third of which was related to visceral stent complications. Intraprocedural complexity was documented during the cannulation of 8 (3.5%) target vessels, with a technical success rate of 98.7%. A significant endoleak or visceral stent failure was identified in 22 stents (9.8%) postoperatively, of which 7 (3%) had in-patient reintervention within 30 days. Further reinterventions at 1, 2, and 3 years were 12 (5.4%), 2 (1%), and 1 (0.4%), respectively. Most reinterventions were for renal stents (n=19, 86%). A smaller stent diameter and a shorter length of visceral stent were significant predictors of failure. No other anatomical feature or stent choice was found to be a significant predictor of failure. CONCLUSIONS: The modality of visceral stent failures varies, but renal stents with a smaller diameter and/or shorter length are more likely to fail over time. Their complications and reinterventions are common and carry a significant burden; therefore, close surveillance must be continued long term. CLINICAL IMPACT: With this work we share the methodology adopted at our centre to treat juxtarenal aneurysm with FEVAR. Thanks to this detailed review of anatomical and technical features we provide guidance for endovascular surgeons to face hostile aneurysm with peculiar visceral vessels anatomy. With our findings will also motivate industries in their attempt to produce improved technologies able to overcome issues identified in this paper.

Reinterventions after physician-modified endovascular grafts for treatment of juxtarenal aortic aneurysms are non-detrimental to long-term survival.

OBJECTIVE: Reintervention after endovascular aortic aneurysm repair is common. However, their frequency and impact on mortality after physician-modified endografts (PMEGs) is unknown. This study aims to describe reinterventions after PMEG for treatment of juxtarenal aneurysms and their effect on survival. METHODS: Data from a prospective investigational device exemption clinical trial (Identifier #NCT01538056) from 2011 to 2022 were used. Reinterventions after PMEG were categorized as open or percutaneous and major or minor by Society for Vascular Surgery reporting standards and as high or low magnitude based on physiologic impact. Reinterventions were also categorized by timing, based on whether they occurred within 30 days of PMEG as well as within 1 week of PMEG. Survival was compared between patients who did and did not undergo reintervention and between reintervention subcategories. RESULTS: A total of 170 patients underwent PMEG, 50 (29%) of whom underwent a total of 91 reinterventions (mean reinterventions/patient, 1.8). Freedom from reintervention was 84% at 1 year and 60% at 5 years. Reinterventions were most often percutaneous (80%), minor (55%), and low magnitude (77%), and the most common reintervention was renal stenting (26%). There were 10 early reinterventions within 1 week of PMEG. Two aortic-related mortalities occurred after reintervention. There were no differences in survival between patients who underwent reintervention and those who did not. However, survival differed based on the timing of reintervention. After adjusted analysis, reintervention within one week of PMEG was associated with an increased risk of mortality both compared with late reintervention (hazard ratio, 11.1; 95% confidence interval, 2.7-46.5) and no reintervention (hazard ratio, 5.2; 95% confidence interval, 1.6-16.8). CONCLUSIONS: Reinterventions after PMEG were most commonly percutaneous, minor, and low magnitude procedures, and non-detrimental to long-term survival. However, early reinterventions were associated with increased mortality risk. These data suggest that a modest frequency of reinterventions should be expected after PMEG, emphasizing the critical importance of lifelong surveillance.

Systematic Review of the Current In Vitro Experience of the Endovascular Treatment of Juxtarenal Abdominal Aortic Aneurysms by Fenestrated and Parallel Endografting.

OBJECTIVE: To identify and analyze the published in vitro benchtop experiments for the assessment of endovascular techniques used for the treatment of juxtarenal abdominal aortic aneurysms (jAAAs). DATA SOURCES: Scopus, PubMed, and Web of Science. REVIEW METHODS: A systematic literature search was carried out throughout March 2021 following PRISMA guidelines. Two investigators independently performed title and abstract screening to reveal all benchtop testing evaluating the endovascular treatment of jAAA. RESULTS: A total of 19 studies were included, 8 evaluating fenestrated (FEVAR) and 11 parallel grafts (PGs). FEVAR studies used different custom testing apparatus (n=7) or 3D-printed models (n=1) to analyze dislodgement and migration resistance, misalignment consequences and causation, and bridging stents' radial force, flareability, fatigue, and fracture resistance. All PG studies used silicone-based models to analyze optimal oversizing, sealing length, gutter behavior, and possible reduction. Test evaluation in FEVAR in vitro testing was based on pullout force analysis (N=5), photo evaluation (n=1), fluoroscopy (n=1), X-rays (n=4), CT analysis (n=3), macro- and microscopic evaluation (n=4), water permeability (n=1), and fatigue simulator testing (n=1), while it was based on CT analysis in all PG studies adding ECG-gate in one study. The most frequently tested devices were Zenit (Cook) (n=7), Endurant (Medtronic) (n=5), and Excluder (Gore) (n=5) as main grafts, and Advanta V12 (n=14) as the bridging device. CONCLUSIONS: This systematic review presents a broad analysis of the current in vitro methods evaluating the endovascular treatment of jAAA. Fundamental issues have been benchtop tested in both FEVAR and PGs. The analysis of the included studies allowed to recommend an optimal testing design. In vitro testing is a potential tool to further elucidate points of attention hard to investigate in vivo to finally enhance the endovascular treatment outcomes. Future in vitro studies are needed to evaluate the in vitro performance of all indistinctively used devices in the clinical practice.

EndoSuture aneurysm repair versus fenestrated aneurysm repair in patients with short neck abdominal aortic aneurysm.

OBJECTIVE: The aim of this study was to compare midterm results of EndoAnchors in EndoSuture aneurysm repair (ESAR) versus fenestrated endovascular aneurysm repair (FEVAR) in short neck abdominal aortic aneurysm (AAA). METHODS: All patients who underwent an ESAR procedure for a short neck AAA at our center between September 2017 and May 2020 were considered for analysis. To form the control group, preoperative computed tomography angiography of patients who underwent FEVAR for juxtarenal AAA between April 2012 and May 2020 were reviewed and patients who met short neck criteria selected. A propensity-matched score on neck length and neck diameter was calculated, resulting in 18 matched pairs. AAA shrinkage, type Ia endoleaks (EL), AAA-related reinterventions, and AAA-related deaths were compared. RESULTS: The median AAA diameter was 54 mm (interquartile range [IQR], 52-61 mm) versus 58 mm (IQR, 53-63 mm) with a median neck length of 8 mm (IQR, 6-12 mm) vs 10 mm (IQR, 6-13 mm) in ESAR and FEVAR patients, respectively. Technical success was 100% in both groups. Procedural success was 94% in the ESAR group versus 100% in the FEVAR group. The median procedure duration was 138 mm (IQR, 113-182 mm) vs 240 mm (IQR, 199-293 mm) ( P < .001) and the median length of stay was 2 days (IQR, 2-3 days) vs 7 days (IQR, 6-7 days) (P < .001) in ESAR and FEVAR patients, respectively. No major hospital complications were observed in ESAR patients compared with two in FEVAR patients (11%) with one transient acute kidney injury and one transient paraplegia. The median follow-up was 23 months (IQR, 19-33 months) vs 36 months (IQR, 22-57 months) with 67% versus 61% AAA shrinkage in the ESAR and FEVAR groups, respectively (P = .73). No type Ia EL, proximal neck-related reinterventions, or AAA-related deaths were observed in either group. No AAA-related reintervention was observed in the ESAR group versus three reinterventions in the FEVAR group (P = .23). CONCLUSIONS: ESAR seems to be a safe technique with no major postoperative complications or reinterventions observed during follow-up. It seems to offer similar midterm results as FEVAR in terms of type Ia EL, aneurysm shrinkage, and aneurysm-related mortality. ESAR seems to be a good off-the-shelf alternative to FEVAR in case of technical constraints.

Proximal seal dilatation following fenestrated endovascular repair for complex abdominal aortic aneurysms.

OBJECTIVE: Although proximal neck dilatation following infrarenal endovascular aneurysm repair (EVAR) is common and is associated with proximal graft failure, little is known about sealing zone dilatation and its clinical relevance following fenestrated EVAR (FEVAR). We studied proximal seal dilatation (PSD) dynamics following FEVAR and assessed its clinical significance. METHODS: We included all consecutive patients treated for a juxta-/supra-renal aneurysm with fenestrated EVAR using the Zenith Fenestrated Endovascular Graft (Cook Medical, Bloomington, Ind) from 2008 to 2018 in two large teaching hospitals in the Netherlands. The primary outcome was PSD over time and was determined using a linear mixed-effects model. Secondary outcomes included associations for early PSD and difference in aortic dilatation at the level of the covered stent compared with the bare stent. Proximal seal-related adverse events were also obtained. RESULTS: Our cohort included 84 patients with a median computed tomography angiography follow-up time of 24.5 months (interquartile range [IQR], 17-42 months). Maximum aneurysm diameter was 60.1 mm (IQR, 56.9-67.2 mm). Mean proximal seal diameter at baseline was 26.2 mm (standard deviation [SD], ±2.8 mm), mean stent oversizing was 20.1% (SD, ±9.1%), and mean proximal seal length was 29.5 mm (SD, ±11.7 mm). Proximal seal dilatation of 1.7 mm (95% confidence interval [CI], 1.4-2.1 mm) was found in the first year, decelerating thereafter (second year, 0.9 mm/year; 95% CI, 0.7-1.1 mm/y). Over 10% PSD at 1 year occurred in 22 patients (27%) and was associated with stent graft oversizing (odds ratio, 1.1; 95% CI, 1.03-1.2; P = .008) and a lower number of target vessels (four fenestrations/ref two fenestrations: odds ratio, 0.13; 95% CI, 0.02-0.74; P = .029). At last available imaging, dilatation difference was higher at the level of the covered stent compared with the bare stent (3.0 mm [IQR, 1.3-5.1 mm] vs 1.6 mm [IQR, 0.8-2.5 mm]; P < .001). During the study period, only one patient (1.2%) developed a proximal seal-related adverse event (type IA endoleak). CONCLUSIONS: PSD is present following FEVAR, occurring at a faster rate in the first year and subsequently decelerating thereafter, similarly to neck dilatation after standard infrarenal EVAR. Although its clinical implication seems to remain limited in the first years following implantation, further research is required to assess the effect of PSD on long-term FEVAR outcomes.

Anatomic characteristics associated with superior mesenteric artery stent graft placement during fenestrated para/suprarenal aneurysm repair.

OBJECTIVE: According to the instructions for use, fenestrated endovascular aortic aneurysm repair (FEVAR) with the Zenith fenestrated endograft (ZFEN; Cook Medical, Bloomington, Ind) requires ≥4 mm of nonaneurysmal infrarenal neck length, and superior mesenteric artery (SMA) stenting is optional. In the present study, we evaluated the outcomes of FEVAR with SMA stent grafting relative to SMA scallops or unstented fenestrations and their anatomic differences. METHODS: We performed a single-institution retrospective analysis of patients who had undergone FEVAR with an SMA scallop or large fenestration with and without SMA stent grafting from June 2012 to May 2020 after institutional review board approval. RESULTS: Of the 203 aneurysms repaired with ZFENs, 127 were included in our analysis. Of these 127 aneurysms, 55 had stent grafted SMA fenestrations, 38 unstented SMA fenestrations, and 34 SMA scallops. Technical success was achieved in all patients. The operative times were longer (335.5 ± 16.4 minutes vs 265.0 ± 12.8 minutes vs 269.0 ± 12.7 minutes; P < .001) and the transfusion rates were higher (33% vs 8% vs 18%; P = .01) in the SMA stent graft group. However, the fluoroscopy time (65.4 ± 3.76 minutes vs 58.3 ± 3.94 minutes vs 51.4 ± 4.75 minutes; P = .05) and contrast volume (92.2 ± 5.17 mL vs 87.1 ± 6.73 mL vs 93.1 ± 5.89 mL; P = .84) were not significantly different. Anatomically, the patients who had undergone FEVAR with a ZFEN and SMA stent grafting had had shorter infrarenal neck (1.73 ± 1.18 mm vs 4.92 ± 1.16 mm vs 6.28 ± 1.42 mm; P = .03) and infra-SMA neck (10.3 ± 1.39 mm vs 23.9 ± 1.24 mm vs 26.8 ± 1.67 mm; P < .001) lengths. In the SMA stent graft group, one patient had developed small bowel necrosis after embolization of an intraoperatively perforated jejunal branch and two had developed colonic ischemia of unclear etiology with patent SMA stent grafts found on imaging. Endograft migration and SMA occlusion with bowel ischemia occurred in one patient in the SMA fenestration group. Overall mortality (24% vs 21% vs 18%; P = .82) and 30-day mortality (5% vs 3% vs 3%; P = .80) were comparable between the three groups. In addition, the incidence of type III endoleak (5% vs 3% vs 3%; P = .45) and the need for reintervention (20% vs 18% vs 12%; P = .60) were similar across all three groups. The mean follow-up duration was longer for the SMA scallop group, which can be attributed to 82% of these occurring in the first one half of the study period. CONCLUSIONS: Despite the added technical complexity, SMA stenting enabled FEVAR in patients with pararenal and suprarenal aneurysms with high rates of technical success and no increased risk of mortality, major adverse events, type III endoleaks, or reintervention.

Physician-Modified Endografts Versus Chimney/Snorkel for Ruptured and Symptomatic Juxtarenal and Paravisceral Aneurysms in the Vascular Quality Initiative.

OBJECTIVES: Ruptured and symptomatic juxtarenal and paravisceral aneurysms present technical challenges during endovascular repair. We sought to compare physician modification and fenestrated (PMEG) versus chimney/periscope/snorkel (CHIMPS) repair techniques for the treatment of ruptured and symptomatic paravisceral and juxtarenal aortic aneurysms (r/sPJAA). METHODS: Patients in the thoracic and complex endovascular aneurysm module of the Vascular Quality Initiative (VQI) national registry undergoing CHIMPS and PMEG for r/sPJAA were included. Patients who underwent thoracic aneurysm repair with only celiac intervention or who had coverage or occlusion only of one renal or visceral branch vessel were excluded. One-year mortality was the primary outcome. Secondary outcomes included peri- and postoperative endoleak, hospital and ICU length of stay, reintervention, and other local and systemic complications. RESULTS: A total of 81 CHIMPS and 47 PMEG patients were identified. Patients undergoing PMEG were more frequently symptomatic, had a history of CHF and were taking aspirin, statin and P2Y12 antiplatelet medications. Patients undergoing CHIMPS presented more frequently with rupture. There was no significant survival advantage for CHIMPS over PMEG patients (P = 0.5). There were no apparent long-term differences in the numbers of endoleaks or in the rates of subsequent reinterventions between the two groups. CONCLUSIONS: It does not appear that the procedure type (CHIMPS versus PMEG) is associated with postoperative survival in patients with r/sPJAA. Not surprisingly, survival is associated with postoperative complications, particularly myocardial infarction and intestinal ischemia. Further research should evaluate reasons for failure to rescue from and the impact of postoperative complications on the postoperative survival after endovascular repair of r/sPJAA.

Stent Graft Modification to Preserve Intercostal Arteries Using Thoracoabdominal Off-the-Shelf Multibranched (t-Branch) Endograft.

Purpose: To demonstrate an off-the-shelf multibranched (t-Branch) modification to allow intercostal arteries preservation during juxtarenal, pararenal, paravisceral, and extent IV thoracoabdominal aortic aneurysm repair. Technique: The t-Branch is an off-the-shelf device not customized for specific patient anatomy and may be offered for urgent endovascular repair for patients with complex aortic aneurysms. However, a concern when treating patients who do not aneurysms extending above the celiac axis is that the more proximal extension which is required with this device may render patients at high risk for spinal cord injury. We report a novel technique with t-Branch modification performing a 180° fabric back windows at the first 2 sealing stents that allow perfusion to the intercostal arteries. Conclusion: T-Branch-PIA (preserving intercostal arteries) modification limits intercostal arteries coverage while optimizing proximal seal zone in juxtarenal, pararenal, paravisceral, and extent IV thoracoabdominal aneurysms, thereby may decrease the risk of spinal cord injury.

A systematic review of three-dimensional printed template-assisted physician-modified stent grafts for fenestrated endovascular aneurysm repair.

OBJECTIVE: Fenestrated endovascular aneurysm repair has yet to gain widespread adoption owing to the technical complexity and increased risk of complications. Three-dimensional (3D) printed templates to guide fenestrated physician-modified stent grafts (PMSGs) are a novel technique that may have the potential to increase the accuracy of fenestration alignment, and to disrupt both the cost and timing of the current commercial fenestrated endograft supply chain. We have conducted a critical appraisal of the emerging literature to assess this. METHODS: A systematic literature search was performed using PubMed and OVID Medline as guided by the PRISMA statement on April 30, 2020. We used "3D printing" and "physician modified" or "surgeon modified" and all related search terms. We identified 50 articles which met our search criteria. None articles were included as being of direct relevance to 3D-printed template-assisted PMSGs for fenestrated endovascular aneurysm repair. Abstracts were screened individually by each investigator to ensure relevance. RESULTS: Nine relevant articles were identified for critical analysis. These included one technical report, five case reports or series, two prospective trials, and one letter to the editor. CONCLUSIONS: These 3D-printed templates are a promising new avenue to assist with the placement of fenestrations in PMSGs, particularly in urgent or emergent cases where custom fenestrated endografts are unavailable, with larger scale studies warranted. Further work to validate the key stages of the template workflow are required, as well as further investigation into the most suitable manufacturing and distribution methods before the mainstream implementation of this novel technique.

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.

Editor's Choice - Fenestrated or Branched Endovascular versus Open Repair for Complex Aortic Aneurysms: Meta-Analysis of Time to Event Propensity Score Matched Data.

OBJECTIVE: The aim of this review was to investigate comparative outcomes of fenestrated or branched endovascular aneurysm repair (F/BEVAR) with open repair for juxta/para/suprarenal or thoraco-abdominal aortic aneurysms. METHODS: Electronic bibliographic sources (MEDLINE and Embase) were interrogated using the Healthcare Databases Advanced Search interface. Eligible studies compared F/BEVAR with open repair for complex aortic aneurysms using propensity score or Cox regression modelling/multivariable logistic regression analysis. Pooled estimates of peri-operative outcomes were calculated using the odds ratio (OR) and 95% confidence interval (CI). The result of time to event analysis was reported as summary hazard ratio (HR) and 95% CI. Random effects models and the inverse variance method were applied. The quality of evidence was graded using the system developed by the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) working group. RESULTS: Eleven studies published between 2014 and 2019 were selected for inclusion in qualitative and quantitative synthesis reporting a total of at least 7 061 patients. The odds of peri-operative mortality after F/BEVAR were lower, although not significantly, than after open repair (OR 0.56, 95% CI 0.28-1.12), whereas the hazard of overall mortality during follow up was higher following F/BEVAR, but, again, without reaching statistical significance (HR 1.25, 95% CI 0.93-1.67). The hazard of re-intervention was significantly higher after endovascular therapy (HR 2.11, 95% CI 1.39-3.18). The certainty for the body of evidence for peri-operative and overall mortality during follow up was judged to be very low and moderate, respectively, and for re-intervention it was judged to be high. CONCLUSION: The evidence is uncertain about the effect of F/BEVAR on peri-operative mortality when compared with open repair. There is probably no difference in overall survival, but F/BEVAR results in an increased re-intervention hazard. There is a need for high level evidence to inform decision making and vascular/aortic service provision.

Gutter Characteristics and Stent Compression of Self-Expanding vs Balloon-Expandable Chimney Grafts in Juxtarenal Aneurysm Models.

Purpose: To assess in silicone juxtarenal aneurysm models the gutter characteristics and compression of different types of chimney graft (CG) configurations. Materials and Methods: Fifty-seven combinations of Excluder C3 or Conformable Excluder stent-grafts (23, 26, and 28.5 mm) were deployed in 2 silicone juxtarenal aneurysm models with 3 types of CGs: Viabahn self-expanding (VSE; 6 and 13 mm) or Viabahn balloon-expandable (VBX; 6, 10, and 12 mm) stent-grafts and Advanta V12 balloon-expandable stent-grafts (ABX; 6 and 12 mm). Setups were divided into 4 groups on the basis of increasing CG and main graft (MG) diameters. Two independent observers assessed gutter size and type as well as CG compression on computed tomography scans using postprocessing software. Results: In the smaller diameter combinations (6-mm CG and 23-, 26-, and 28.5-mm MGs), both VSE (p=0.006 to 0.050) and ABX (p=0.045 to 0.050) showed lower gutter areas and volumes compared with VBX. In turn, the VBX showed a nonsignificant tendency to decreased compression, especially compared to ABX. Use of the Excluder C3 showed a 6-fold increase in type A1 gutters (related to type Ia endoleak) as compared to the Conformable Excluder (p=0.018). Balloon-expandable stent-grafts (both ABX and VBX) showed a 3-fold increase in type A1 gutters in comparison with self-expanding stent-grafts (p=0.008). Conclusion: The current study suggests that use of the Conformable Excluder in combination with VSE chimney grafts is superior to the other tested CG/MG combinations in terms of gutter size, gutter type, and CG compression.

Three-dimensional printing-guided fenestrated endovascular aortic aneurysm repair using open source software and physician-modified devices.

Fenestrated endovascular aneurysm repair is frequently used for juxtarenal and pararenal aortic aneurysms. In urgent cases, however, the use of premanufactured patient-specific devices is not an option. Physician-modified endografts may be used to treat these patients but require experience and a steep learning curve for accurate planning to position fenestrations and to perform the graft modifications. Despite experience, a margin of error in placing fenestrations always exists, and a mismatch possibility between the fenestration and vessel ostium can lead to increased cannulation time and stent complications, including target vessel loss. Aortic three-dimensional printing has been widely described in medicine for simulation, training, and surgical planning. Commercial software is currently under investigation for planning of fenestrated endovascular aneurysm repair at high costs. We describe an effective and inexpensive technique using free computer-aided design software to create a real 1:1 aortic 3D model that can easily be printed and quickly sterilized. This aortic model can be used to create a physician-modified endograft and to place fenestrations in an accurate way, with potential for shorter and more precise procedures and better long-term results. Two cases are presented to illustrate the technique, demonstrating that 3D printing is a valuable tool to plan, design, and create fenestrated devices more accurately.

Early results of endovascular aneurysm sealing with chimney grafts to treat juxtarenal and suprarenal abdominal aortic aneurysms.

BACKGROUND: The treatment of juxtarenal abdominal aortic aneurysms is challenging. Open surgical repair is not a viable option for many patients. The use of endovascular aneurysm sealing (EVAS) with chimney grafts (Ch-EVAS) has been proposed as an immediately available, off-the-shelf option for individuals with juxtarenal aneurysms who require urgent treatment or are unsuitable for fenestrated or branched devices. This study reports the outcomes from our first patients to undergo this procedure. METHODS: Data were collected prospectively for 62 consecutive patients undergoing Ch-EVAS at our institution. The procedures were undertaken for intact juxtarenal or suprarenal aneurysms in patients who were unfit for open repair or needed urgent treatment or when the aneurysm morphology was unsuitable for treatment with fenestrated or branched endografts. RESULTS: Between July 2013 and June 2016, there were 62 patients who were treated with Ch-EVAS; 77.4% were male, and the mean age was 73.9 years. Median aneurysm diameter was 64.5 mm. Eight suprarenal aneurysms were treated, with three chimney grafts. Of 54 juxtarenal aneurysms treated, 21 cases used two chimney grafts and 33 cases used one chimney graft. Median follow-up was 407 days. Eleven patients underwent reintervention. There were five type IA endoleaks, all successfully treated. One type IB and one type II endoleak occurred, neither requiring treatment. There were four minor strokes. Chimney patency is 97%. CONCLUSIONS: These results in a group of high-risk patients suggest that Ch-EVAS is a viable alternative to custom-made devices in patients who are unfit for open surgery. Longer term follow-up and data from the international registry will determine the widespread applicability and durability of this technique.

Secondary Fill Minimizes Gutter Size in Chimney EVAS Configurations In Vitro.

PURPOSE: To investigate in an in vitro model if secondary endobag filling can reduce gutter size during chimney endovascular aneurysm sealing (chEVAS). MATERIALS AND METHODS: Nellix EVAS systems were deployed in 2 silicone juxtarenal aneurysm models with suprarenal aortic diameters of 19 and 24 mm. Four configurations were tested: EVAS with 6-mm balloon-expandable (BE) or self-expanding (SE) chimney grafts (CGs) in the renal branches of both models. Balloons were inflated simultaneously in the CGs and main endografts during primary and secondary endobag filling and polymer curing. Computed tomography (CT) was performed immediately after the primary and secondary fills. Cross-sectional lumen areas were measured on the CT images to calculate gutter volumes and percent change. CG compression was calculated as the reduction in lumen surface area measured perpendicular to the central lumen line. The largest gutter volume and highest compression were presented per CG configuration per model. RESULTS: Secondary endobag filling reduced the largest gutter volumes from 99.4 to 73.1 mm3 (13.2% change) and 84.2 to 72.0 mm3 (27.6% change) in the BECG configurations and from 67.2 to 44.0 mm3 (34.5% change) and 92.7 to 82.3 mm3 (11.2% change) in the SECG configurations in the 19- and 24-mm models, respectively. Secondary endobag filling increased CG compression in 6 of 8 configurations. BECG compression changed by -0.2% and 5.4% and by -1.0% and 0.4% in the 19- and 24-mm models, respectively. SECG compression changed by 10.2% and 16.0% and by 7.2% and 7.3% in the 19- and 24-mm models, respectively. CONCLUSION: Secondary endobag filling reduced paragraft gutters; however, this technique did not obliterate them. Increased CG compression and prolonged renal ischemia time should be considered if secondary endobag filling is used.

Procedural and perioperative results in patients treated with fenestrated endovascular aneurysm repair planned by automated software in a physician-sponsored investigational device exemption trial of physician-modified endografts.

OBJECTIVE: Fenestrated endovascular aneurysm repair (FEVAR) has been used successfully to treat patients with juxtarenal abdominal aortic aneurysms (JAAAs). Barriers to wide adoption of FEVAR include complexity in planning of fenestration locations on endografts. The purpose of this study was to validate the use of automated planning software to design fenestrated endografts and to treat patients with complex abdominal aortic aneurysms. METHODS: Patients with JAAA who were not candidates for open repair were enrolled into the automated planning arm of an ongoing investigational device exemption clinical trial and treated with FEVAR. Patient-specific fenestration size and location were determined by automated planning software using patient imaging data and algorithms that account for the interaction between the endograft delivery system and angulated aortic anatomy. Standard, off-the-shelf abdominal aortic aneurysm endografts from multiple manufacturers were modified on the back table by the physician according to the automated graft plan in the form of a patient-specific three-dimensional printed cylindrical template. Endografts typically included fenestrations for the superior mesenteric artery and both renal arteries. Procedural, perioperative, and long-term clinical and imaging data were collected per protocol. RESULTS: Thirty nonoperative JAAA candidate patients (American Society of Anesthesiologists class ≥3) were consented and treated with fenestrated endografts planned by automated software. The mean age was 74 ± 7 (61-86) years. The mean aneurysm diameter was 61.3 mm (range, 49-96 mm), and the mean infrarenal neck length was 6.1 mm (range, 2-15 mm). At the index procedure, 100% (30/30) of the patient-specific, surgeon-modified grafts were implanted with preservation of 97% (84/87) of branch vessels and a mean final proximal seal zone length of 41.9 mm (range, 27.3-60.6 mm). Three renal arteries were not cannulated during the index procedure because of complications not related to graft planning. The 30-day mortality rate in these high-risk JAAA patients was 6.7% (2/30), and both deaths were unrelated to the aneurysm. The 30-day major adverse event rate was 16.7% (5/30). There were no type IA or type III endoleaks, ruptures, or conversions to open surgery through 30 days. CONCLUSIONS: This automated FEVAR planning software accurately and efficiently identifies fenestration locations for vital branch arteries, thus simplifying the planning process and facilitating the FEVAR procedure. Validated automated FEVAR planning could help bring this beneficial therapy to most patients harboring JAAAs.

Hemodynamic and Anatomic Predictors of Renovisceral Stent-Graft Occlusion Following Chimney Endovascular Repair of Juxtarenal Aortic Aneurysms.

PURPOSE: To identify anatomic and hemodynamic changes associated with impending visceral chimney stent-graft occlusion after endovascular aneurysm repair (EVAR) with the chimney technique (chEVAR). METHODS: A retrospective evaluation was performed of computed tomography scans from 41 patients who underwent juxtarenal chEVAR from 2008 to 2012 to identify stent-grafts demonstrating conformational changes following initial placement. Six subjects (mean age 74 years; 3 men) were selected for detailed reconstruction and computational hemodynamic analysis; 4 had at least 1 occluded chimney stent-graft. This subset of repairs was systematically analyzed to define the anatomic and hemodynamic impact of these changes and identify signature patterns associated with impending renovisceral stent-graft occlusion. Spatial and temporal analyses of cross-sectional area, centerline angle, intraluminal pressure, and wall shear stress (WSS) were performed within the superior mesenteric and renal artery chimney grafts used for repair. RESULTS: Conformational changes in the chimney stent-grafts and associated perturbations, in both local WSS and pressure, were responsible for the 5 occlusions in the 13 stented branches. Anatomic and hemodynamic signatures leading to occlusion were identified within 1 month postoperatively, with a lumen area <14 mm2 (p=0.04), systolic pressure gradient >25 Pa/mm (p=0.03), and systolic WSS >45 Pa (p=0.03) associated with future chimney stent-graft occlusion. CONCLUSION: Chimney stent-grafts at increased risk for occlusion demonstrated anatomic and hemodynamic signatures within 1 month of juxtarenal chEVAR. Analysis of these parameters in the early postoperative period may be useful for identifying and remediating these high-risk stent-grafts.