Assessment of Bridging Stents in In Situ Laser Fenestrations of Aortic Endografts With Intravascular Ultrasound.

Objective: Treatment of complex aortic aneurysms with the in situ laser fenestration (ISLF) technique involves implantation of a balloon expandable stent graft (bSG) in the created fenestration. Adequate expansion of this bSG is of importance both to achieve seal and to ensure target vessel stability. This experimental study assessed the expansion rate of different bSGs in the ISLF setting using intravascular ultrasound (IVUS). Methods: A commercially available aortic endograft was used to test the laser fenestration technique (Zenith Alpha, Cook Medical LLC, Bloomington, IN, USA). The ISLF was stented with the following bSGs: two Gore Viabahn VBX balloon expandable endoprostheses (WL Gore & Associates, Bloomington, IL, USA), three BeGraft Peripheral and three BeGraft Plus (Bentley InnoMed GmbH; Hechingen, Germany), and three Advanta V12 (Atrium, Hudson, NH, USA). The bSGs were expanded in three steps: (1) nominal, (2) rated burst pressure, and (3) dilation with a non-compliant balloon at 15 atmospheres. After each step, an IVUS assessment of the bSG minimum diameter and the area at the fenestration (FA) and in a fully expanded segment distal to the fenestration (SA) was performed. A mean of the three IVUS measurements was used as the value for comparison. An insufficient bSG expansion was defined as a mean of FA/SA of <0.8 (i.e., <80% expansion). Results: The VBX was the only bSG that could be expanded to its intended diameter (i.e., at least 80%) at nominal pressure. The BeGraft Peripheral and BeGraft Plus had the lowest degree of expansion after nominal and rated burst pressure. All bSGs that were tested reached a sufficient expansion degree after using a higher pressure balloon. Conclusion: In this ex vivo experiment, dilation up to nominal pressure showed satisfactory expansion only for the VBX. The consistency of the results when applied to the different types of stent grafts that were analysed reflects structural stent graft specific issues to consider when choosing the right device in cases of ISLF.

Soluble Glycoprotein VI Predicts Abdominal Aortic Aneurysm Growth Rate and is a Novel Therapeutic Target.

A common feature in patients with abdominal aortic aneurysms (AAA) is the formation of a nonocclusive intraluminal thrombus (ILT) in regions of aortic dilation. Platelets are known to maintain hemostasis and propagate thrombosis through several redundant activation mechanisms, yet the role of platelet activation in the pathogenesis of AAA associated ILT is still poorly understood. Thus, we sought to investigate how platelet activation impacts the pathogenesis of AAA. Using RNA-sequencing, we identify that the platelet-associated transcripts are significantly enriched in the ILT compared to the adjacent aneurysm wall and healthy control aortas. We found that the platelet specific receptor glycoprotein VI (GPVI) is among the top enriched genes in AAA ILT and is increased on the platelet surface of AAA patients. Examination of a specific indicator of platelet activity, soluble GPVI (sGPVI), in two independent AAA patient cohorts is highly predictive of a AAA diagnosis and associates more strongly with aneurysm growth rate when compared to D-dimer in humans. Finally, intervention with the anti-GPVI antibody (JAQ1) in mice with established aneurysms blunted the progression of AAA in two independent mouse models. In conclusion, we show that levels of sGPVI in humans can predict a diagnosis of AAA and AAA growth rate, which may be critical in the identification of high-risk patients. We also identify GPVI as a novel platelet-specific AAA therapeutic target, with minimal risk of adverse bleeding complications, where none currently exist.

Six Years' Experience With a Novel Dissection-Specific Stent-Graft to Prevent Distal Stent-Graft-Induced New Entry.

INTRODUCTION: Thoracic endovascular aortic repair (TEVAR) in chronic dissection is associated with a risk for distal stent-graft-induced new entry (dSINE) in up to a quarter of cases. We assess the mid-term outcome of a novel dissection-specific stent-graft (DSSG), which is a custom-made device based on the Cook Alpha platform, with a modified graft design and a distal endovascular elephant trunk without any supporting stent to reduce the radial force on the dissection membrane at the distal landing zone. METHODS: A retrospective single-center study of chronic dissection patients at high risk of dSINE who received an elective endovascular repair with DSSG from January 2017 to June 2023. The primary outcome is Kaplan-Meier (KM) estimated freedom from dSINE during follow-up. Secondary outcomes included technical success, aortic remodeling, and anatomical evaluation of the distal landing zone in cases with dSINE during follow-up versus those without. RESULTS: Thirty patients (24 males) with a median age of 66 years [range=31-78] underwent elective TEVAR with the DSSG. The majority, n=27 (90%), had previous aortic repair; 7 (23%) had established connective tissue disease, and 6 (20%) had established dSINE after previous stent-graft implantation as an indication for TEVAR. Technical success was achieved in n=29 (97%). Median follow-up was 38.5 months (4.3-76.4), and KM estimated freedom from dSINE at 1 and 3 years was 95.6% (SE 0.043) and 89% (SE 0.081), respectively Four cases developed dSINE during follow-up. The median distance from the distal stent-graft to the coeliac trunk was 74mm (range=18-123) in the dSINE group versus 26mm (range=0-74) in the non-dSINE group (p=0.049). Median proximal tangential aortic angulation in the distal landing zone was 38.5° (range=26°-50°) in the dSINE group compared to 21° (range=3-61°) in the non-dSINE group (p=0.052). CONCLUSIONS: The Use of a novel DSSG with low radial force for TEVAR in the setting of chronic dissection is safe and feasible, with remodeling outcomes comparable with standard TEVAR. The reduced distal radial force in the DSSG does not eliminate the risk for dSINE over time, with new entries occurring, particularly in cases where the distal landing zone is in a tortuous aortic segment and not close to the coeliac trunk. CLINICAL IMPACT: Using the novel dissection-specific stent-graft with reduced radial force is safe and feasible but does not completely eliminate the risk of dSINE occurring over time. The exact positioning of the distal stent-graft in a straight aortic segment, close to the coeliac trunk, may be of importance to further mitigate the risk.

Novel insights into thoracic endografts technology for prevention of distal stent-graft induced new entry (dSINE) following endovascular repair of type B aortic dissections: from bench to bedside.

INTRODUCTION: Endovascular treatment of type B aortic dissections (TBAD) has currently acquired a primary therapeutic role when anatomically feasible. The main issue with thoracic endovascular aortic repair (TEVAR) for aortic dissection is the actual nature of the aortic wall, which is structurally compromised and more fragile. Indeed, a wealth of data have shown that TEVAR for TBAD will lead, in a substantial proportion of cases, to a device-related adverse event named distal stent-graft induced new entry (dSINE). AREAS COVERED: Currently available aortic stent-grafts have not been specifically devised for the treatment of aortic dissection. A novel dissection specific stent-graft (DSSG) was developed, which is a custom-made device based on the Zenith Alpha Thoracic platform (Cook Medical). The DSSG has several unique properties that, in principle, make its use optimal in TBAD patients. EXPERT OPINION: TEVAR in the setting of aortic dissections remains technically challenging. The occurrence of dSINE represents a unique complication in this scenario and may lead to high rates of aortic-related adverse events and need for secondary interventions. The use of a novel custom-made DSSG in the setting of chronic TBAD has been proven to be safe, feasible and effective. However, even this approach may fail to completely prevent dSINE formation.

International Collaborative Study Comparing Outcomes of Fenestrated Endovascular Aortic Repair in OCtogenarian vs Non-Octogenarian Patients: The FEVOC study.

OBJECTIVE: With an increasing life expectancy, more octogenarian patients are referred with complex aortic aneurysms (cAAA). The aim of this study was to evaluate short and mid-term outcomes following fenestrated aortic repair (FEVAR) in octogenarians. SUMMARY BACKGROUND DATA: Few studies looking at octogenarian-specific outcomes with diverging results. METHODS: Retrospective, multicentre cohort study including consecutive patients undergoing elective FEVAR for cAAAs or type IV thoracoabdominal aortic aneurysms between 2007-2022 in eight high-volume centres. Octogenarians vs. non-octogenarians were compared. The primary outcome was 30-day mortality. Secondary outcomes included 1, 2 and 5-year survival and reintervention rates. RESULTS: A total of 729 patients (median age of 74.8 years [IQR 69.2 - 79.14]) were included, 169 (23%) of which were octogenarians, with 316 (43.3%) patients undergoing juxta/pararenal aneurysm repair. Although octogenarians presented less complex but larger (61 mm vs. 58 mm) aneurysms, the number of fenestrations was similar across groups. No differences in in-hospital mortality (4.1 vs. 3.0%), MAE (16.6% vs 12.2%) or reintervention rates (11.2 vs. 10%) were found. Multivariable logistic regression of in-hospital mortality identified BMI (OR 0.66, 95% CI 0.51-0.95, P=0.003), chronic heart failure (OR 7.70, 95% CI 1.36-36.15, P=0.003) and GFR<45 ml/min/1.73 m2 (OR 5.25, 95% CI 1.20-22.86, P=0.027) as independent predictors. Median follow-up was 41 months. The 1, 2 and 5-year survival rates were 91.3%, 81.8% and 49.5% in octogenarians vs 90.6%, 86.5% and 68.8% in non-octogenarian patients (Log-rank: =0.001). Freedom from aortic-related death and freedom from reintervention at five-years were similar across groups (log-rank=0.94 and .76, respectively). Age>80 was not an independent predictor of 30-day or long-term mortality on multivariable and Cox regression analysis. CONCLUSIONS: Elective FEVAR in octogenarians appears to be safe, with similar outcomes as in younger patients. Future studies looking at improved patient selection methods to ensure long-term survival benefits in both octogenarians and younger patients are warranted.

A Core Outcome Set for Intact Abdominal Aortic Aneurysm Repair.

OBJECTIVE: Technology and advances in clinical care have changed the management of abdominal aortic aneurysms (AAAs) but the clinical effectiveness of continuing advances needs to be assessed. To facilitate rapid synthesis of new evidence and improve stakeholder representation, including patients, the concept of core outcome sets (COS) has been developed. COS, reflecting the needs of all stakeholders, have been established across several surgical specialties. This study aimed to develop an international core outcome set for intact AAA repair. METHODS: Following COMET methodology, potential outcomes were identified from a systematic review of published outcomes and focus groups involving patients, carers, and nurses. A 38 question Delphi consensus survey in lay language was developed (with translation to local languages); this included 35 themes identified from the findings of the systematic review and three themes from the focus groups. All three of the themes identified by the focus groups (cognitive, physical, and social functioning) can be evaluated from quality of life instruments, with overall quality of life being identified from the systematic review. The survey was completed by patients, carers or family members, vascular nurses, vascular surgeons, trainees, interventional radiologists, anaesthetists, and industry partners from six European countries. After two rounds of the survey, the top outcomes were discussed at a face to face multistakeholder consensus meeting. RESULTS: The 38 item questionnaire was amended after piloting among all stakeholder groups. After the first round of the Delphi survey (98 respondents) 15 questions were eliminated, and 11 further questions were eliminated after round 2 (90 respondents). This left two outcome questions for discussion at the consensus meeting, where the top six outcomes were unanimously endorsed: death at 30 days (or in hospital if longer), secondary AAA rupture, overall quality of life and retention of cognitive functioning after recovery, five year survival, and continued sac growth. CONCLUSION: Six core outcomes are recommended for use as a minimum framework in all future studies and registries of intact open and endovascular AAA repair. Further work to select instruments for quality of life and to define instruments for cognitive functioning is needed.

In situ laser fenestration of the Thoraflex Hybrid frozen elephant trunk for emergent revascularization of the left subclavian artery and laser fenestration for spinal cord perfusion.

In situ laser fenestration (ISLF) has emerged as a promising technique for emergent revascularization of the left subclavian artery in the case of thoracic endovascular aortic repair coverage, presenting excellent technical success rates in most studies. We describe a case of ISLF of the Thoraflex Hybrid frozen elephant trunk device to achieve immediate left subclavian artery revascularization. We demonstrate the feasibility and technical success of using ISLF in this setting, providing a less invasive alternative to conventional surgical revascularization when required.

Editor's Choice -- European Society for Vascular Surgery (ESVS) 2024 Clinical Practice Guidelines on the Management of Abdominal Aorto-Iliac Artery Aneurysms.

OBJECTIVE: The European Society for Vascular Surgery (ESVS) has developed clinical practice guidelines for the care of patients with aneurysms of the abdominal aorta and iliac arteries in succession to the 2011 and 2019 versions, with the aim of assisting physicians and patients in selecting the best management strategy. METHODS: The guideline is based on scientific evidence completed with expert opinion on the matter. By summarising and evaluating the best available evidence, recommendations for the evaluation and treatment of patients have been formulated. The recommendations are graded according to a modified European Society of Cardiology grading system, where the strength (class) of each recommendation is graded from I to III and the letters A to C mark the level of evidence. RESULTS: A total of 160 recommendations have been issued on the following topics: Service standards, including surgical volume and training; Epidemiology, diagnosis, and screening; Management of patients with small abdominal aortic aneurysm (AAA), including surveillance, cardiovascular risk reduction, and indication for repair; Elective AAA repair, including operative risk assessment, open and endovascular repair, and early complications; Ruptured and symptomatic AAA, including peri-operative management, such as permissive hypotension and use of aortic occlusion balloon, open and endovascular repair, and early complications, such as abdominal compartment syndrome and colonic ischaemia; Long term outcome and follow up after AAA repair, including graft infection, endoleaks and follow up routines; Management of complex AAA, including open and endovascular repair; Management of iliac artery aneurysm, including indication for repair and open and endovascular repair; and Miscellaneous aortic problems, including mycotic, inflammatory, and saccular aortic aneurysm. In addition, Shared decision making is being addressed, with supporting information for patients, and Unresolved issues are discussed. CONCLUSION: The ESVS Clinical Practice Guidelines provide the most comprehensive, up to date, and unbiased advice to clinicians and patients on the management of abdominal aorto-iliac artery aneurysms.

Statin therapy after elective abdominal aortic aneurysm repair improves long-term survival.

BACKGROUND: Patients with abdominal aortic aneurysms are at high risk of cardiovascular events. Although statin therapy is indicated for most of these patients, no specific recommendation regarding the intensity of therapy exists. The aim of this study was to assess the possible effect of statin therapy on survival of patients undergoing abdominal aortic aneurysm repair and to investigate if high-intensity statin therapy was superior to low-moderate-intensity therapy. METHODS: Data from nationwide Swedish registers on hospital admissions, operations, and medications for patients undergoing elective abdominal aortic aneurysm repair from 2006 to 2018 were collected. The effect of statin use was evaluated in three separate propensity score matched cohorts: perioperative mortality was analysed according to whether patients were on statins before abdominal aortic aneurysm repair or not; long-term survival was assessed according to whether patients were on statins during follow-up or not; and, for those on statins after surgery, long-term survival was analysed according to whether patients were on high-intensity or low-moderate-intensity statin therapy. RESULTS: Preoperative statin use did not reduce 90-day perioperative mortality (OR 0.99, 95% c.i. 0.77 to 1.28), whilst there was a marked benefit regarding long-term survival for postoperative statin users (HR 1.43, 95% c.i. 1.34 to 1.54). High-intensity statin therapy had no advantage over low-medium-intensity statin therapy with regards to long-term survival (HR 1.00, 95% c.i. 0.80 to 1.25). CONCLUSION: In this nationwide propensity score matched cohort study, preoperative statin treatment had no benefit regarding 90-day perioperative survival, but postoperative statin treatment markedly improved long-term survival. No additional benefit regarding high-dose statin treatment could be confirmed in this analysis.

Intravascular Ultrasound in the Detection of Bridging Stent Graft Instability During Fenestrated and Branched Endovascular Aneurysm Repair Procedures: A Multicentre Study on 274 Target Vessels.

OBJECTIVE: The use of intravascular ultrasound (IVUS) reduces contrast medium use and radiation exposure during conventional endovascular aneurysm repair (EVAR). The aim of this study was to evaluate the safety and efficacy of IVUS in detecting bridging stent graft (bSG) instability during fenestrated and branched EVAR (F/B-EVAR). METHODS: This was a prospective observational multicentre study. The following outcomes were evaluated: (1) technical success of the IVUS in each bSG, (2) IVUS findings compared with intra-operative angiography, (3) incidence of post-operative computed tomography angiography (CTA) findings not detected with IVUS, and (4) absence of IVUS related adverse events. Target visceral vessel (TVV) instability was defined as any branch or fenestration issues requiring an additional manoeuvre or re-intervention. Any IVUS assessment that detected stenosis, kinking, or any geometric TVV issue was considered to be branch instability. All procedures were performed in ad hoc hybrid rooms. RESULTS: Eighty patients (69% males; median age 72 years; interquartile range 59, 77 years) from four aortic centres treated with F/B-EVAR between January 2019 and September 2021 were included: 70 BEVAR (21 off the shelf; 49 custom made), eight FEVAR (custom made), and two F/B-EVAR (custom made), for a total of 300 potential TVVs. Two TVVs (0.7%) were left unstented and excluded from the analysis. The TVVs could not be accessed with the IVUS catheter in seven cases (2.3%). Furthermore, 17 (5.7%) TVVs could not be examined due to a malfunction of the IVUS catheter. The technical success of the IVUS assessment was 91.9% (274/298), with no IVUS related adverse events. Seven TVVs (2.5%) showed signs of bSG instability by means of IVUS, leading to immediate revisions. The first post-operative CTA at least 30 days after the index procedure was available in 268 of the 274 TVVs originally assessed by IVUS. In seven of the 268 TVVs (2.6%) a re-intervention became necessary due to bSG instability. CONCLUSION: This study suggests that IVUS is a safe and potentially valuable adjunctive imaging technology for intra-operative detection of TVV instability. Further long term investigations on larger cohorts are required to validate these promising results and to compare IVUS with alternative technologies in terms of efficiency, radiation exposure, procedure time, and costs.

Editor's Choice - Systematic Review and Meta-Analysis of Contemporary Abdominal Aortic Aneurysm Growth Rates.

OBJECTIVE: To evaluate the contemporary growth rate of small abdominal aortic aneurysms (AAAs) in view of recent epidemiological changes, such as decreasing smoking rates and establishment of population screening programmes. DATA SOURCES: MEDLINE, CENTRAL, PsycINFO, Web of Science Core Collection, and OpenGrey databases. REVIEW METHODS: Systematic review following the PRISMA guidelines. In October 2021, databases were queried for studies reporting on AAA growth rates published from 2015 onwards. The primary outcome was contemporary AAA growth rates in mm/year. Data were pooled in a random effects model meta-analysis, and heterogeneity was assessed through the I2 statistic. GRADE assessment of the findings was performed. The protocol was published in PROSPERO (CRD42022297404). RESULTS: Of 8 717 titles identified, 43 studies and 28 277 patients were included: 1 241 patients from randomised controlled trials (RCTs), 23 941 from clinical observational studies, and 3 095 from radiological or translational research studies. The mean AAA growth rate was 2.38 mm/year (95% CI 2.16 - 2.60 mm/year; GRADE = low), with meta-regression analysis adjusted for baseline diameter showing an increase of 0.08 mm/year (95% CI 0.024 - 0.137 mm/year; p = .005) for each millimetre of increased baseline diameter. When analysed by study type, the growth rate estimated from RCTs was 1.88 mm/year (95% CI 1.69 - 2.06 mm/year; GRADE = high), while it was 2.31 mm/year (95% CI 1.95 - 2.67 mm/year; GRADE = moderate) from clinical observational studies, and 2.85 mm/year (95% CI 2.44 - 3.26 mm/year; GRADE = low) from translational and radiology based studies (p < .001). Heterogeneity was high, and small study publication bias was present (p = .003), with 27 studies presenting a moderate to high risk of bias. The estimated growth rate from low risk studies was 2.09 mm/year (95% CI 1.87 - 2.32; GRADE = high). CONCLUSION: This study estimated a contemporaneous AAA growth rate of 2.38 mm/year, being unable to demonstrate any clinically meaningful AAA growth rate reduction concomitant with changed AAA epidemiology. This suggests that the RESCAN recommendations on small AAA surveillance are still valid. However, sub-analysis results from RCTs and high quality study data indicate potential lower AAA growth rates of 1.88 - 2.09 mm/year, findings that should be validated in a high quality prospective registry.

A novel off-the-shelf single-fenestrated stent graft for emergent complex aortic aneurysm repair.

The off-the-shelf single fenestrated stent graft is based on the Cook Zenith fenestrated platform (Cook Medical Europe) with a premade 8-mm fenestration for the superior mesenteric artery (SMA). The device is suitable for emergency treatment of paravisceral aneurysms when combined with in situ laser fenestration for the renal arteries (and, if required, the celiac trunk). The presence of a premade SMA fenestration results in minimal visceral ischemia time. We present the case of a 69-year-old woman with a ruptured Crawford type I thoracoabdominal aortic aneurysm and a tandem abdominal aortic aneurysm that was treated successfully using the single fenestrated device with in situ laser fenestration for the renal arteries, with no SMA ischemia time. A 6-month computed tomography angiogram showed patent renovisceral stents without an endoleak.

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.