Endovascular Aortic Repair Procedures Research Articles

Characterization of cerebrospinal fluid markers as indicators of spinal cord ischemia following an endovascular aortic aneurysm repair procedure.

Spinal cord ischemia (SCI) remains one of the most devastating complications in both open and endovascular stent graft repair of thoracoabdominal aortic aneurysms. The endovascular aortic aneurysm repair (EVAR) can be either thoracic (TEVAR) when it targets the thoracic aortic aneurysm or fenestrated branched when repair involves the visceral and/or renal arteries. Even though EVAR interventions are less invasive than open repair, they are still associated with a significant risk of SCI. The current primary strategy to prevent SCI after TEVAR is to increase and/or maintain spinal cord perfusion pressure (blood flow) by increasing the mean arterial pressure while simultaneously draining CSF. Although the benefit of CSF drainage in EVAR procedures remains uncertain, it provides an opportunity to study the changes in cytokine and oxidative stress markers that may signal the pathophysiology of SCI following EVAR. The aim of this study was to evaluate the temporal relationship between stent deployment and CSF cytokine and oxidative stress marker levels as predictors of delayed SCI in patients undergoing an EVAR procedure. There were 16 EVAR cases across 15 patients enrolled in this study, with 1 patient undergoing the procedure twice 1 year apart. The levels of oxidative stress (8-hydroxy-2'-deoxyguanosine [8-OHdG], glial fibrillary acidic [GFAP], and lactic acid) and proinflammatory (tumor necrosis factor-alpha [TNF-α], interleukin (IL)-6, and IL-1β) and antiinflammatory (IL-4) markers were quantified at different time points between 0 and 48 hours after EVAR by enzyme-linked immunosorbent assay. The changes in protein levels of both oxidative stress and inflammatory markers were expressed as fold change from the time of the lumbar drain insertion prior to surgery. Following the EVAR procedure, 8-OHdG resulted in the highest upregulation at later time points postoperatively (48 hours) and this increase was positively correlated with TNF-α level. The data also revealed that IL-6 peaked during the stent deployment intervention and this pattern of expression was positively correlated with the expression of lactic acid. No significant changes were noted in the expression levels of GFAP, lactic acid, and IL-1β. There appears to be a temporal relationship between lumbar CSF drainage and CSF cytokines and oxidative stress markers that may help 1) identify patients at risk for developing delayed SCI and 2) modify patient management to prevent the damage from delayed SCI.

Role of Antiplatelet Therapy in Patients Managed for Complex Aortic Aneurysms using Fenestrated or Branched Endovascular Repair

Despite the increasing number of fenestrated/branched endovascular aortic repair (f/bEVAR) procedures, evidence on post-operative antiplatelet therapy is lacking. This study aimed to investigate the role of single antiplatelet therapy (SAPT) vs. double antiplatelet therapy (DAPT) after f/bEVAR on 30 day and follow up outcomes. A multicentre retrospective analysis was conducted, including f/bEVAR patients managed from 1 January 2018 to 31 December 2022. Comparative outcomes were assessed according to post-operative antiplatelet therapy. The cohort was divided into the SAPT group (acetylsalicylic acid [ASA] or clopidogrel) and DAPT group (ASA and clopidogrel). The duration of SAPT or DAPT was one to six months. Primary outcomes were 30 day death, and cardiovascular ischaemic and major haemorrhagic events. Secondary outcomes were survival and target vessel (TV) patency during follow up. A total of 1 430 patients were included: 955 under SAPT and 475 under DAPT. The 30 day mortality was similar (SAPT 2.1% vs. DAPT 1.5%; p = .42). Cardiovascular ischaemic events were lower in the DAPT group (SAPT 11.9% vs. DAPT 8.2%; p = .040), with DAPT being an independent protector for acute mesenteric (p = .009) and lower limb ischaemia (p = .020). No difference was found in 30 day major haemorrhagic events (SAPT 7.5% vs. DAPT 6.3%; p = .40). The mean follow up was 21.8 ± 2.9 months. Cox regression showed no cofounders on survival, with similar rates between groups (log rank p = .71). DAPT patients presented higher TV patency (SAPT 93.4%, standard error [SE] 0.7% vs. DAPT 96.6%, SE 0.7%; log rank p = .007) at thirty six months. Cox regression revealed bEVAR as a predictor of worse TV patency (hazard ratio 2.03, 95% confidence interval 1.36 - 3.03; p < .001). DAPT was related to higher patency within bEVAR patients (SAPT 87.2%, SE 2.1% vs. DAPT 94.9%, SE 1.9%; p < .001). DAPT after f/bEVAR was associated with lower risk of cardiovascular ischaemic events and higher TV patency, especially in bEVAR cases. No difference in major haemorrhagic events was observed at 30 days.

Unsupervised machine learning cluster analysis to identification EVAR patients clinical phenotypes based on radiomics.

This study used unsupervised machine learning (UML) cluster analysis to explore clinical phenotypes of endovascular aortic repair (EVAR) for abdominal aortic aneurysm (AAA) patients based on radiomics. We retrospectively reviewed 1785 patients with infra-renal AAA who underwent elective EVAR procedures between January 2010 and December 2020. Pyradiomics was used to extract the radiomics features. Statistical analysis was applied to determine the radiomics features that related to severe adverse events (SAEs) after EVAR. The selected features were used for UML cluster analysis in training set and validation in test set. Comparison of basic characteristics and radiomics features of different clusters. The Kaplan-Meier analysis was conducted to generate the cumulative incidence of freedom from SAEs rate. A total of 1180 patients were enrolled. During the follow-up, 353 patients experienced EVAR-related SAEs. In total, 1223 radiomics features were extracted from each patient, of which 23 radiomics features were finally preserved to identify different clinical phenotypes. 944 patients were allocated to the training set. Three clusters were identified in training set, in which patients had identical clinical characteristics and morphological features, while varied considerably of selected radiomics features. This encouraging performance was further approved in the test set. In addition, each cluster was well differentiated from other clusters and Kaplan-Meier analysis showed significant differences of freedom from SAEs rate between different clusters both in the training (p = .0216) and test sets (p = .0253). Based on radiomics, UML cluster analysis can identify clinical phenotypes in EVAR patients with distinct long-term outcomes.

Long-term outcomes of chimney endovascular aneurysm repair procedure for complex abdominal aortic pathologies

ObjectiveThe aim of this study was to update our earlier experience and to evaluate long-term outcomes of chimney endovascular aortic repair performed for selected cases with complex abdominal aortic aneurysm. MethodsA single-center retrospective cohort study was conducted on 51 consecutive patients who underwent chimney endovascular aortic repair procedure, deemed unfit for open surgical repair and fenestrated endovascular aneurysm repair, from October 2009 to November 2019. Kaplan-Meier analyses were used to assess the estimated overall survival, freedom from aneurysm related mortality, freedom from reintervention, freedom from target vessel instability, and freedom from type Ia endoleaks. ResultsFifty-one patients (mean age, 77.1 ± 7.5 years) with a mean preoperative maximum aneurysm diameter of 74.2 ± 20.1 mm were included. Mean follow-up duration was 48.6 months (range, 0-136 months). Estimated overall survival at 5 and 7 years was 36.3% ± 7.1% and 18.3% ± 6.0%, respectively. Freedom from aneurysm-related mortality was 88.6% ± 4.9% at 7 years. Estimated freedom from type Ia endoleaks at 7 years was 91.8% ± 3.9%. A total of 21 late reinterventions were performed in 17 patients (33%). Most of them were performed to treat type II endoleaks with sac growth (47.6%; n = 10) and type Ib endoleak (23.8%; n = 5). Estimated freedom from reintervention at 7 years was 56.3% ± 7.9%. Estimated freedom from target vessel instability at 7 years was 91.5% ± 4.1%. ConclusionsThe 7-year results of chimney endovascular aortic repair procedures performed in our center confirm the long-term safety and effectiveness of this technique in a series of high-risk patients with large aneurysms. The present study has, to the best of our knowledge, the longest follow-up for patients treated with chimney endovascular aortic repair, and it provides data to the scarce literature on the long-term outcomes of this procedure, showing acceptable to good long-term results.

Preclinical Evaluation of a Modular Inner-Branched Stent Graft to Reconstruct the Left Subclavian Artery in Thoracic Endovascular Aortic Repair: Experimental Study in Pigs.

In approximate 40% of thoracic endovascular aortic repair (TEVAR) procedures, the left subclavian artery (LSA) needs to be covered to obtain sufficient proximal sealing zone. To preserve the LSA during the TEVAR for type B aortic dissection (TBAD) adjacent to LSA, our team designed a modular single inner-branched stent graft. This study was performed to evaluate the safety and feasibility of deploying a modular single inner-branched stent graft in a porcine model. Modular inner-branched stent grafts were implanted in 14 pigs via right femoral and right carotid arterial access. Computed tomography angiography (CTA) and angiography were performed in all pigs to appraise the morphological characteristics of the stent grafts at the end of follow-up. The pigs were then euthanized, and tissues were collected for gross and histological examination. The technical success rate was 100% (14/14). One pig suddenly died 5 hours after operation, and 1 pig died after completing the follow-up CTA. During the follow-up period, all surviving pigs showed good mental state, normal diets and activities. Computed tomography angiography examinations showed that all stent grafts were intact without fracture. All bridging covered stents were patent. Angiography showed that the position, shape, and adhesion of the stent grafts were good, and no obvious endoleaks were found. Histological examination showed that the biocompatibility of the stent grafts was good. This study's outcomes demonstrate that it is safe and feasible to deploy a modular single inner-branched stent graft in a porcine model. This device is the first modular device designed to treat TBAD adjacent to LSA in China. This device is a modular two-component system consisting of a thoracic aortic stent graft with a retrograde inner branch and a bridging covered stent. The modular design and the retrograde inner branch are the two important innovations of this device. Theoretically, the device could make it easier and safer for clinicians to treat TBAD adjacent to the LSA.

Incidence of endoleak type IA in patients undergoing chimney endovascular aortic repair (ChEVAR) vs. standard endovascular repair.

Almost half of endovascular aortic aneurysm repair (EVAR) procedures are performed in hostile anatomy, increasing the risk of procedure related complications such as type IA endoleaks, which may be prevented with the chimney technique in EVAR (ChEVAR). Our aim is to describe the differential characteristics between EVAR in favorable anatomy and ChEVAR in hostile necks. A cohort of patients with infrarenal abdominal aortic aneurysms (AAA) that were treated with EVAR or ChEVAR were included. The primary outcome was the incidence of type IA endoleak. Secondary outcomes were the rate of chimney occlusion, reintervention, migration, rupture, acute limb ischemia, sac growth, and aneurysm-related mortality during the follow-up period. . With a median follow-up of 11.5 months, 79 patients were treated with EVAR and 21 with ChEVAR. The overall age was 76.49 ± 7.32 years old, and 82% were male. The ChEVAR cohort had a higher prevalence of tobacco use than the EVAR cohort (38.1% vs. 17.7%, p = 0.041), and a shorter neck (7.88 mm ± 5.73 vs 36.28 mm ± 13.73, p<0.001). There were no differences in type IA endoleak incidence between the groups (a single endoleak type IA in the EVAR group, p = 0.309). One patient experienced an asymptomatic chimney occlusion in the ChEVAR group, and another patient required a reintervention due to chimney occlusion. Sac regression and reinterventions were not different between groups. There were no migration, rupture, acute limb ischemia, or aneurysm-related mortality events. . In patients with abdominal aortic aneurysms, ChEVAR in hostile necks had similar event rates to EVAR in favorable necks.

Endovascular management of aortic aneurysm with severe neck angulation and/or iliac artery tortuosity using multiple stiff wire technique: a case series.

Suitable aortic neck is one of the essential components for thoracic endovascular aortic repair (TEVAR) and endovascular aortic repair (EVAR). Advanced techniques were developed to adjust and compromise the aneurysm neck angulation but with adding additional devices and complexity to the procedure. We proposed a simple technique to modify severe neck angulation and/or iliac artery tortuosity by using the multiple stiff wire (MSW) technique. Two femoral accesses were required for the MSW technique. A guidewire with a support catheter was inserted through the right and left femoral arteries and positioned in the abdominal or thoracic aorta. Wire exchanges were done with extra stiff wire in both femoral accesses. It can be considered to add multiple stiff wires to align the torturous neck / iliac artery. Delivery of the stent graft main body can be done via one of the accesses. Six patients with different aortic pathology were admitted to our hospital. Four patients undergo EVAR procedure and two patients undergo TEVAR procedure. All patients had aortic neck angulation problems with one patient having iliac artery tortuosity. MSW technique was performed on the patients with good results. Follow-up CTA after 3 months revealed a good stent position without stent migration and no endoleak was found in all but one patient. MSW technique is a simple and effective technique to modify aortic neck/iliac artery angulation in TEVAR or EVAR procedure.

A deformed Lunderquist wire in a percutaneous endovascular aortic aneurysm repair procedure

Introduction: An endovascular aortic aneurysm repair (EVAR) is a minimally invasive procedure for repairing an abdominal aneurysm. The advantage of this procedure is that EVAR does not require a laparotomy, hence reducing the physical insult to the body with a quicker recovery time for the patient. Percutaneous EVAR (PEVAR) involves accessing the femoral arteries percutaneously using an access needle without the need of a groin dissection. In this case, a guidewire was damaged and an emergency ‘cut down’ was required to repair the femoral artery. Case: An 85-year-old woman attended for an elective EVAR. The initial access was gained via percutaneous punctures to both her common femoral arteries under ultrasound guidance. On completion of the procedure the guidewire was removed with difficulty and an emergency right femoral dissection was performed and the common femoral artery was repaired. Postoperatively, the patient recovered well and was discharged the following day after observation. Discussion: In PEVAR there is no need to make an incision to dissect down to the vessels. Although the vascular closure device comes with an access wire, a standard wire can be passed through; in this case, a stiff wire was used. After removal of the guidewire from the right groin it was found that the wire was severely deformed. It is thought that the wire was caught in the calcium within the vessel. Conclusion: Although PEVAR is a common procedure, one must be mindful that many factors can affect the endovascular access and closure of the patient. The wire was damaged in this case, either in the femoral artery or in the closure device. It is paramount for vascular surgeons to anticipate that this could be a complication of PEVAR.

Access site complications in thoracic endovascular aortic repair

BackgroundPercutaneous access and use of vascular closure devices facilitate thoracic endovascular aortic repair (TEVAR) procedures during local anesthesia and allow immediate detection of signs of spinal ischemia. However, the very large bore access (usually ≥22F sheath) associated with TEVAR increases the risk of vascular complications. In this study, we sought to define the safety and feasibility of two percutaneous femoral artery closure devices during TEVAR, in terms of access site vascular complications and major, life-threatening, or fatal bleeding (≥major) within 48 hours. Access site vascular complications were defined as technical failure of vascular closure or later formation of pseudoaneurysm. MethodsFrom March 2010 to December 2022, 199 transfemoral TEVAR were performed at Helsinki University Central Hospital, Finland. We retrospectively categorized these into three groups, based on surgeon preference for the access technique and femoral artery closure method: (1) surgical cut-down and vessel closure, n = 85 (42.7%), (2) percutaneous access and vascular closure with suture-based ProGlide, n = 56 (28.1%), or (3) percutaneous access and vascular closure with ultrasound-guided plug-based MANTA, n = 58 (29.1%). The primary outcome measure was technical success of vascular closure and access site vascular complications during index hospitalization. Secondary outcome measures were ≥major bleeding, early mortality, and hospital stay. ResultsThe technical success rate was 97.6% vs 91.1% vs 93.1% for surgical cut-down, ProGlide, and MANTA, respectively (P = .213). The rate of access site vascular complication was 3.5% vs 8.9% vs 10.3%, respectively (P = .290), with two pseudoaneurysms detected postoperatively and conservatively managed in the MANTA group. The vascular closure method was not associated with increased risk of ≥major bleeding, early mortality, or hospital stay on univariate analysis. Predictors for ≥major bleeding after TEVAR in multivariable analysis were urgent procedure (odds ratio: 2.8, 95% confidence interval: 1.4-5.5; P = .003) and simultaneous aortic branch revascularization (odds ratio: 2.7, 95% confidence interval: 1.3-5.4; P = .008). ConclusionsIn this study, the technical success rates of the percutaneous techniques demonstrated their feasibility during TEVAR. However, the number of access site complications for percutaneous techniques was higher compared with open approach, although the difference was not statistically significant. In the lack of evidence, the safety of the new MANTA plug-based vascular closure for TEVAR warrants further investigation.

Operation time and clinical outcomes for open infrarenal abdominal aortic aneurysms to remain stable in the endovascular era.

Endovascular aortic repair (EVAR) has become a routine procedure worldwide. Ultimately, the increasing number of EVAR cases entails changing conditions for open surgical repair (OSR) regarding patient selection, complexity, and surgical volume. This study aimed to assess the time trends of open abdominal aortic aneurysm (AAA) repair in a high-volume single center in Austria over a period of 20 years, focusing on the operation time and clinical outcomes. A retrospective analysis of all patients treated for infrarenal AAAs with OSR or EVAR between January 2000 and December 2019 was performed. Infrarenal AAA was defined as the presence of a >10-mm aortic neck. Cases with ruptured or juxtarenal AAAs were excluded from the analysis. Two cohorts of patients treated with OSR at different time periods, namely, 2000-2009 and 2010-2019, were assessed regarding demographical and procedure details and clinical outcomes. The time periods were defined based on the increasing single-center trend toward the EVAR approach from 2010 onward. A total of 743 OSR and 766 EVAR procedures were performed. Of OSR cases, 589 were infrarenal AAAs. Over time, the EVAR to OSR ratio was stable at around 50:50 (p = 0.488). After 2010, history of coronary arterial bypass (13.4% vs. 7.2%, p = 0.027), coronary artery disease (38.1% vs. 25.1%, p = 0.004), peripheral vascular disease (35.1% vs. 21.3%, p = 0.001), and smoking (61.6% vs. 34.3%, p < 0.001) decreased significantly. Age decreased from 68 to 66 years (p = 0.023). The operation time for OSR remained stable (215 vs. 225 min, first vs. second time period, respectively, p = 0.354). The intraoperative (5.8% vs. 7.2%, p = 0.502) and postoperative (18.3% vs. 20.8%, p = 0.479) complication rates also remained stable. The 30-day mortality rate did not change over both time periods (3.0% vs. 2.4%, p = 0.666). Balanced EVAR to OSR ratio, similar complexity of cases, and volume over the two decades in OSR showed stable OSR time without compromise in clinical outcomes.

Abstract 14516: Combined Platelet Morphology and Clinicoradiological Features to Predict Type II Endoleaks Following Endovascular Abdominal Aortic Aneurysm Surgery

Introduction: Persistent endoleak and associated endotension following endovascular abdominal aortic aneurysm repair (EVAR) can compromise successful repair and lead to continued sac expansion and eventual life-threatening rupture event. Hypothesis: A risk-stratification algorithm of the inherent anatomical and systemic cellular characteristics of patients might predict the incidence of type II endoleaks on abdominal aortic aneurysm (AAA) patients undergoing EVAR or fenestrated endovascular aortic aneurysm repair (FEVAR) procedures. Methods: Single-center retrospective study includes 146 AAA patients undergoing primary elective EVAR and FEVAR procedures between September 2013 and July 2021. A review of institutional medical records was conducted for the analysis. Patients who or who did not developed a type II endoleaks were included in this study. Results: Mean platelet volume (MPV) was significantly increased in patients with type II endoleaks and was associated with lower endoleak-free survival. Receiver operating characteristic (ROC) curve analysis showed that MPV demonstrated satisfactory predictive performance in distinguishing patients who developed type II endoleaks, yielding an area under the curve (AUC) value of 0.64. A risk-stratification panel consisting of postoperative MPV, history of type II diabetes, and number of preoperative patent lumbar arteries achieved an AUC value of 0.72 and predicted endoleak-free survival rate with HR of 4.88. We built an easy-to-use nomogram for predicting the risk of postoperative type II endoleak and revealed that MPV had the highest scoring weight of any variable in our model. Conclusions: We refined the anatomical and systemic traits in the blood that identified MPV as a significant predictor for type II endoleaks, which might facilitate post-surgical monitoring using complete blood count (CBC) as a supplement to imaging practice.

Rapid artificial ventricular pacing for thoracic endovascular aortic repair

Aim: Rapid artificial ventricular pacing (RAVP) is a reproducible method for rapid and reversible reduction of transvascular flow during endovascular procedures. This method has the potential to increase patient tolerance, reduce operation duration, infection risk, X-ray dose and facilitate early patient mobilisation. The aim of this study to compare the efficacy, safety and impact of RAVP and pharmacological-induced hypotension in patients who underwent thoracic endovascular aortic repair (TEVAR) procedures for aortic dissection and aneurysm. Material and Methods: This retrospective, observational, case-control study was conducted between January 2014 and December 2022. The adult patients who underwent TEVAR procedures for aortic dissection and aneurysm were enrolled in this study. Mean arterial pressure, heart rate, total operation duration, incidence of endoleak, duration of intensive care unit-hospitalization stay, and hospital mortality ratio were compared between nitroglycerin induced hypotension group and RAVP group. Results: A total of 279 patients who underwent TEVAR procedures were included in this study. The mean age of patients in this cohort was 65.6±5.7 years and 158 (56.6%) of the patients were male. Of these 279 patients, hypotension during stent-graft was achieved with nitroglycerin in 155 patients. There were no statistical differences between these two groups in terms of age, gender, body mass index, comorbidities and drugs. The blood pressure lowering effect and the heart rate during the intervention was significantly higher in RAVP. Endoleak and hospital mortality rates were similar in each group. Conclusion: RAVP is a feasible and safe method because it paves the way for agile maneuvers to maintain optimal hemodynamic conditions. Besides this, more meticulous, accurate deployment of endograft can be established with RAVP.

The value of metal artifact reduction and iterative algorithms in dual energy CT angiography in patients after complex endovascular aortic aneurysm repair

Rationale and objectivesEvaluation of the diagnostic value of linearly blended (LB) and virtual monoenergetic images (VMI) reconstruction techniques with and without metal artifacts reduction (MAR) and of adaptive statistical iterative reconstructions (ASIR) in the assessment of target vessels after branched/fenestrated endovascular aortic repair (f/brEVAR) procedures. Materials and methodsCT scans of 28 patients were used in this study. Arterial phase of examination was obtained using a dual-energy fast-kVp switching scanner. CT numbers in the aorta, celiac trunk, superior mesenteric artery, and renal arteries were measured in the following reconstructions: LB, VMI 60 keV, VMI MAR 60 keV, VMI ASIR 60 % 60 keV. Contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) were calculated for each reconstruction. Luminal diameters (measurements at 2 levels of stent) and subjective image quality (5-point Likert scale) were assessed (2 readers, blinded to the type of reconstruction). ResultsThe highest mean values of CNR and SNR in vascular structures were obtained in VMI MAR 60 keV (CNR 12.526 ± 2.46, SNR 17.398 ± 2.52), lower in VMI 60 keV (CNR 11.508 ± 2.01, SNR 16.524 ± 2.07) and VMI ASIR (CNR 11.086 ± 1.78, SNR 15.928 ± 1.82), and the lowest in LB (CNR 6.808 ± 0.79, SNR 11.492 ± 0.79) reconstructions. There were no statistically significant differences in the measurements of the stent width between reconstructions (p > 0.05). The highest subjective image quality was obtained in the ASIR VMI (4.25 ± 0.44) and the lowest in the MAR VMI (1.57 ± 0.5) reconstruction. ConclusionDespite obtaining the highest values of SNR and CNR in the MAR VMI reconstruction, the subjective diagnostic value was the lowest for this technique due to significant artifacts. The type of reconstruction did not significantly affect vessel diameter measurements (p > 0.05). Iterative reconstructions raised both objective and subjective image quality.

Strategy for Totally Percutaneous Management of Vascular Injury in Combined Transfemoral Transcatheter Aortic Valve Replacement and Endovascular Aortic Aneurysm Repair Procedures

Minimally invasive treatment of severe aortic stenosis by transcatheter aortic valve replacement (TAVR) and infrarenal abdominal aortic aneurysm by endovascular aortic aneurysm repair (EVAR) requires large-bore vascular access. These percutaneous transfemoral interventions may be performed as a combined procedure, however, vascular injury may necessitate surgical vascular repair. We implemented a strategy designed to enable percutaneous vascular repair, with stent-graft implantation, if necessary, after these combined procedures. We identified all combined percutaneous TAVR and EVAR procedures which were performed at our institution. Patient and procedural characteristics and clinical outcomes were analyzed. Six consecutive patients underwent total percutaneous combined TAVR and EVAR procedures. In all cases, TAVR was performed first and was followed by EVAR. Both common femoral arteries served as primary access sites for delivery of the implanted devices and hemostasis was achieved by deployment of vascular closure devices. Secondary access sites included the right brachial artery in all patients and superficial femoral arteries in 50% of the patients. In all cases an "0.014" 300-cm length "safety" wire was delivered to the common femoral artery or descending aorta by way of a secondary access site to facilitate stent graft delivery. Successful device implantation was achieved in all cases. Vascular closure device failure occurred in 2 patients and was treated by stent graft implantation by way of the brachial and superficial femoral arteries, without need for surgical vascular repair. A strategy designed to facilitate percutaneous vascular repair after combined EVAR and TAVR procedures may enable a truly minimally invasive procedure.

Monte Carlo Dosimetry Validation for X-Ray Guided Endovascular Procedures

Endovascular treatment is continuously gaining ground in vascular surgery procedures. However, current patient radiation dose estimation does not take into account the exact patient morphology and organs' composition. Monte Carlo (MC) simulation can accurately estimate the dose by recreating the irradiation process generated during X-ray-guided interventions. This study aimed to validate the MC simulation models by comparing simulated and measured dose distributions in endovascular aortic aneurysm repair (EVAR) procedures. We conducted a clinical study in patients treated for EVAR. Patient dose measurements were taken with passive dosimeters using Optically Stimulated Luminescence technology in 4 specific anatomical points on the skin: xiphoid process, pubic symphysis, right and left iliac crest. Dose measurements were compared to the corresponding simulated doses with the Geant4 Application for Emission Tomography (GATE) and GPU Geant4-based Monte Carlo Simulations (GGEMS) MC simulations softwares. The MC simulation took as input the computed tomography scan of the patient and the parameters of the imaging system (orientation angles, tube voltage, and aluminum filtration) and gives as output the three-dimensional (3D) dose map for each patient and angulation. A good agreement with real doses was found for doses simulated by the MC GATE method (P<0.0001; r=0.97; 95% confidence interval [CI] [0.96-0.98]), as well as for doses simulated by the GGEMS method (P<0.0001; r=0.96; 95% CI [0.94-0.97]). The mean relative error for all measurements was 5±5% in the MC GATE group and 6±5% in the GGEMS group. Process execution on GGEMS (6sec) was faster than the GATE MC simulation (5hr). Considering the current imaging settings, this study shows the potential of using the GATE and GGEMS MC simulations platforms to model the 3D dose distributions during EVAR procedures.

Endovascular management of aortic aneurysm with severe neck angulation and/or iliac artery tortuosity using multiple stiff wire technique: a case series

Background: Suitable aortic neck is one of the essential components for thoracic endovascular aortic repair (TEVAR) and endovascular aortic repair (EVAR). Advanced techniques were developed to adjust and compromise the aneurysm neck angulation but with adding additional devices and complexity to the procedure. We proposed a simple technique to modify severe neck angulation and/or iliac artery tortuosity by using the multiple stiff wire (MSW) technique. Method: Two femoral accesses were required for the MSW technique. A guidewire with a support catheter was inserted through the right and left femoral arteries and positioned in the abdominal or thoracic aorta. Wire exchanges were done with extra stiff wire in both femoral accesses. It can be considered to add multiple stiff wires to align the torturous neck / iliac artery. Delivery of the stent graft main body can be done via one of the accesses. Result: Six patients with different aortic pathology were admitted to our hospital. Four patients undergo EVAR procedure and two patients undergo TEVAR procedure. All patients had aortic neck angulation problems with one patient having iliac artery tortuosity. MSW technique was performed on the patients with good results. Follow-up CTA after 3 months revealed a good stent position without stent migration and no endoleak was found in all but one patient. Conclusion: MSW technique is a simple and effective technique to modify aortic neck/artery angulation in TEVAR or EVAR procedure.

Influence of Patient Anatomy on Intraoperative Radiation Exposure and Operation Time during Standard EVAR.

Endovascular aortic repair (EVAR) is the primary treatment for abdominal aortic aneurysms (AAAs). To optimise patient safety during the standard EVAR procedure, we aimed to investigate the influence of patient anatomy on intraoperative radiation exposure and surgical time. This retrospective study comprised 90 patients (mean age 73.4 ± 8.2 years; 92.2% male) with an infrarenal aortic aneurysm who underwent a standard EVAR procedure. The relationships between dose area product, operating time, and anatomical conditions were investigated in preoperative computed tomography angiography using open-source software. Logistic regression analysis indicated that only body mass index (BMI) had predictive value for radiation exposure. The accuracy of the model was 98.67%, with an area under the curve of 0.72. The duration of surgery was significantly correlated with an increased BMI (odds ratio (OR) = 1.183; p < 0.05), the tortuosity of AAAs (OR = 1.124; p < 0.05), and the left common iliac artery (OR = 1.028; p < 0.05). Thus, BMI impacts the prediction of intraoperative radiation exposure more significantly than the anatomical characteristics of the infrarenal aorta and iliac arteries, and the duration of surgery significantly correlates with both BMI and the tortuosity of the infrarenal aorta and iliac arteries.

The Flux One Magnetic Navigation System: A Preliminary Assessment for Stent Implantation

Minimally-invasive surgery (MIS) for stent implantation is a complex procedure requiring specialized instruments. It often leads to prolonged patient recovery, and interrupted operations due to incorrect instrument selection and complex anatomy. This study presents a novel magnetic navigation system that addresses these challenges by using magnetic fields and computed tomography imaging to precisely navigate minimally-invasive surgical guidewires. The system is designed based on consultations with surgeons, and analysis of technical and clinical requirements of stent implantation procedures. Results from a human-in-the-loop case study with eleven operators indicate a 47% reduction in guidewire navigation times, while successfully reaching all predetermined luminal targets. The clinical relevance, usability, and operator satisfaction are also measured using a user experience questionnaire, and interviews and showed positive results. Compared to conventional, manual guidewire navigation, the magnetic navigation system has the potential to significantly impact the efficiency of the clinical workflow and improve complex endovascular aortic repair procedures.

Analysis of Determinants for Suture-mediated Closure Device Failure During EVAR Procedures.

Endovascular aortic repair (EVAR) for elective and emergency infrarenal aortic pathologies is the primary approach for treatment nowadays. During such procedure, the suture-mediated closure device (SMCD) (Perclose ProGlideTM, Abbott Laboratories, Chicago, IL, USA) is commonly used. This study aimed to identify potential contributors for SMCD failure in a patient cohort of elective and emergency EVAR. Archived medical records from patients who underwent EVAR for aortic pathologies in elective and emergency setting at the University Hospital Düsseldorf, Germany were included. Patient's co-morbidities, access vessel morphologies and hemostasis-related blood parameters were evaluated on their association with SMCD failure applying different statistical methods. A total of 71 patients (139 femoral accesses) was included. The mean age was 73.5 ± 8.4years. Overall SMCD failure rate was 4.3%, 4.1% for elective and 5.9% for emergency cases, respectively. Total procedure time was longer for the SMCD failure group (323 ± 117.8min vs 171 ± 43.7min). The calcification status of the common femoral artery (CFA), the diameter of the aortic bifurcation, and dual anti-platelet therapy (DAPT) on the medication plan prior to the procedure were associated with SMCD failure. Univariate binary logistic regression analysis nominated several potentially relevant predictors for SMCD failure who underwent subsequent multivariable binary logistic regression analysis. Here, DAPT on the medication plan was identified as being promising in predicting SMCD failure (OR 30.5), while anterior plaque formation in the CFA maintained as only statistically relevant determinant (OR 44.9). This study confirms the CFA calcification status to be associated with SMCD failure. Although discontinued prior to endovascular treatment, DAPT was also found to be associated with SMCD failure. Our results may advocate to perform obligatory platelet testing prior to EVAR to maximize patient safety.

Early experience with bridging stent graft deployment without sheath support in branched and fenestrated endovascular aortic repair

ObjectiveTo assess the early experience with modified version of simplified bare-wire target vessel (SMART) technique, implying delivery of bridging stent grafts without historically established sheath support, and to compare its outcome to standard endovascular aortic repair procedures with fenestrated/branched devices. MethodsA retrospective analysis of 102 consecutive patients treated with fenestrated/branched devices from January 2020 to December 2022 was undertaken. The study population was divided into three groups—a sheath group (SG), SMART group, and nonsheath group (NSG). Primary end points were radiation exposure (dose-area product), fluoroscopy time, dose of contrast agent, operation time, and incidence of intraoperative target vessel (TV) complications and additional procedures. Freedom from secondary TV related reinterventions at the three follow-up phases were defined as secondary end points. ResultsA total of 183 TVs (38.8% visceral arteries [VA]; 56.3% renal arteries [RA]) in the SG, 36 TVs (44.4% VA, 55.6% RA) in the SMART group, and 168 TVs (47.6% VA; 50% RA) in the NSG were accessed. The mean number of fenestrations and bridging stent grafts was equally distributed in all three groups. The SMART group only included cases treated with fenestrated devices. The dose-area product was significantly lower in the SMART (median, 203 Gy × cm2; interquartile range [IQR], 179-365 Gy × cm2) and NSG (median, 340 Gy × cm2; IQR, 220-651 Gy × cm2) groups vs the SG (median, 464 Gy × cm2; IQR, 267-871 Gy × cm2; P = .007). Operation time was also significantly lower in the NSG (median, 265 minutes; IQR, 221-337 minutes) and SMART (median, 292 minutes; IQR, 234-351 minutes) groups vs the SG (median, 326 minutes; IQR, 277-375 minutes; P = .004), respectively. Intraoperative TV-related complications were most frequently observed in the SG (9/183 TVs; P = .008). ConclusionsThis study reports the outcomes of three currently available TV stenting approaches. Previously reported SMART technique, and its modified version (NSG) proved to be a safe alternative to historically established TV stenting technique with sheath support (SG).