Endovascular Aortic Procedures Research Articles

The Gore Viabahn balloon-expandable stent graft as bridging stent in complex endovascular aortic procedures at 3-years performs better in fenestrations

Complex endovascular procedures are now recognized as the gold standard treatments for extensive aortic diseases. Bridging stents (covered stents used to couple the aortic graft to the visceral vessels) play a pivotal role, yet there is currently no dedicated device available on the market. The aim of the study was to evaluate the mid-term performance of the Gore Viabahn balloon-expandable (VBX) stent graft as a bridging stent for target visceral vessels (TVV). Data from all consecutive patients undergoing fenestrated and branched endovascular aortic repair (F/BEVAR) and receiving the VBX stent graft as a bridging stent between July 2018 and September 2022 were prospectively collected and subsequently analyzed retrospectively. Primary endpoints included freedom from TVV instability and freedom from TVV-related reinterventions, both overall and in comparison between branched and fenestrated graft configurations. Secondary endpoints were overall survival, procedure and TVV-related (in an intent-to-treat basis) technical success, freedom from type IC/IIIC endoleak, and freedom from TVV patency loss. Sixty-three patients were treated with a F/BEVAR using VBX as bridging stent, of those 47 (74.6%) presented an atherosclerotic aneurysm, 7 (11.1%) a post-dissecative aneurysm and 9 (14.3%) an anastomotic pseudoaneursym or a type IA endoleak in a previous EVAR. Included in the aortic repair were 231 out of 243 (95.1%) total visceral vessels. The intra-operative requirement of 13 additional VBX determined a TVV-related technical success of 94.4%. Mean follow-up was 26.1 ± 16.4 months. Estimated overall survival at 36-months was 73 ± 7.5%. Estimated rates at 36-months for freedom from type IC/IIIC endoleaks and TVV primary patency were 90.6 ± 3.9% and 99 ± 0.7%, respectively. Estimated rate at 36-months for freedom from TVV-instability was 92.1 ± 3% and did not differ between branched and fenestrated configurations, while freedom from TVV-related reinterventions was 90.6 ± 3.1% and significantly in favor of fenestrations (69.4% versus 96.8%, p< .001). Multivariate analyses confirmed fenestrated configuration as a protective factor against TVV-related reinterventions (HR: .079; 95% CI: .016 - .403). The VBX stent graft proves to be a reliable bridging stent for complex aortic procedures involving both fenestrated and branched endografts. While immediate results are deemed satisfactory, they favor fenestrations regarding need of reinterventions through 3-years. The success of the procedure heavily relies on a thorough understanding of the unique characteristics of this stent.

Comparative Evaluation of the Short-Term Outcome of Different Endovascular Aortic Arch Procedures.

Objectives: There are several endovascular treatment options to treat aortic arch and thoracic aortic pathologies with custom-made or surgeon-modified aortic stent grafts. This study seeks to assess endovascular treatment methods for aortic arch and thoracic aortic pathologies with no acceptable proximal landing zone for standard thoracic endovascular aortic repair (TEVAR), comparing different treatment methods and evaluating technical success, intraoperative parameters and short-term outcomes. Methods: All patients undergoing elective or emergency endovascular treatment of aortic arch and thoracic aortic pathologies, with no acceptable landing zone for standard TEVAR, between 1 January 2010 and 31 March 2024, at the University Hospital Düsseldorf, Germany were included. An acceptable landing zone was defined as a minimum of 2 cm for sufficient sealing. All patients were not suitable for open surgery. Patients were categorized by an endovascular treatment method for a comprehensive comparison of pre-, intra- and postoperative variables. IBM SPSS29 was used for data analysis. Results: The patient cohort comprised 21 patients, predominantly males (81%), with an average age of 70.9 ± 9 years with no acceptable proximal landing zone for standard TEVAR procedure. The most treated aortic pathologies were penetrating aortic ulcers and chronic post-dissection aneurysms. Patients were sub-grouped according to the applied procedure as follows: five patients with chimney thoracic endovascular aortic repair (chTEVAR), seven patients with in situ fenestrated thoracic endovascular aortic repair (isfTEVAR), six patients with custom-made fenestrated thoracic endovascular aortic repair (cmfTEVAR) and three patients with custom-made branched thoracic endovascular aortic repair (cmbTEVAR). Emergency procedures involved two patients. There were significant differences in the total procedure and fluoroscopy time, as well as in contrast agent usage among the treatment groups. cmfTEVAR had the shortest total procedure time, while chTEVAR exhibited the highest contrast agent usage. The overall mortality rate among all procedures was 9.5% (two patients) and 4.7% for elective procedures, respectively. Deaths were associated with either retrograde type A dissection or stent graft infection. Both patients were treated with chTEVAR. There was one minor and one major stroke; these patients were treated with isfTEVAR. No endoleak occurred during any procedure. The reintervention rate for chTEVAR was 20% and 0% for all other procedures during the in-hospital stay. The patients who were treated with cmfTEVAR had no complications, the shortest operating and fluoroscopy time, and less contrast agent was needed in comparison with other treatment methods. Conclusions: Complex endovascular procedures of the aortic arch with custom-made or surgeon-modified aortic stent grafts offer a safe solution, with acceptable complication rates for patients who are not suitable for open aortic arch repair. In terms of procedure-related parameters and complication rates, a custom-made fenestrated TEVAR is potentially advantageous compared to the other endovascular techniques.

Single Access and X-Over Reversed Iliac Extension Technique in a PAD Patient Needing Complex Endovascular Aortic Aneurysm Repair.

To describe the X-over reversed iliac extension technique in a patient with severe peripheral arterial disease (PAD) scheduled for inner branched endovascular aortic repair (iBEVAR). A multimorbid 62-year-old male patient was planned for iBEVAR due to a 58 mm suprarenal aortic aneurysm. The patient had a previous right femoropopliteal bypass and stenting of the left iliac axis. At admission, he presented with recent onset severe left limb claudication, which was attributed to left iliac stent occlusion. To avoid the postoperative compression of the right common femoral artery (CFA) and preserve the patency of the bypass, a single left CFA access, followed by left iliac artery recanalization, was decided. The right iliac axis was catheterized with a Lunderquist wire using X-over access from the left CFA. An iliac extension (ZISL, 24-59, Cook Medical, Bloomington, USA) was reversed and resheathed on back-table and implanted in the right common iliac artery using the X-over technique. The left CFA access was used to complete the remaining steps of the procedure. The predischarge computed tomography angiography confirmed bilateral iliac artery and femoropopliteal bypass patency. The X-over reversed iliac extension technique may be applied in selected PAD patients, when undergoing complex endovascular aortic repair. As the number of patients with peripheral arterial disease (PAD) is expected to increase the upcoming decades, out of the box solutions may be needed to assist complex endovascular aortic management. The X over technique, which consist of the contralateral advancement of an on-table reversed iliac limb, was successfully applied in a patient with severe PAD and numerous previous peripheral interventions, who was managed with branched endovascular aortic repair . The X Over technique may provide an additional alternative in well-selected patients with demanding vascular access undergoing complex endovascular aortic procedures.

A computational study of artery curvature and endograft oversize influence on seal zone behavior in endovascular aortic repair

Thoracic endovascular aortic repair (TEVAR) is a minimally invasive procedure involving the placement of an endograft inside the dissection or an aneurysm to direct blood flow and prevent rupture. A significant challenge in endovascular surgery is the geometrical mismatch between the endograft and the artery, which can lead to endoleak formation, a condition where blood leaks between the endograft and the vessel wall. This study uses computational modeling to investigate the effects of artery curvature and endograft oversizing, the selection of an endograft with a larger diameter than the artery, on endoleak creation. Finite element analysis is employed to simulate the deployment of endografts in arteries with varying curvature and diameter. Numerical simulations are conducted to assess the seal zone and to quantify the potential endoleak volume as a function of curvature and oversizing. A theoretical framework is developed to explain the mechanisms of endoleak formation along with proof-of-concept experiments. Two main mechanisms of endoleak creation are identified: local buckling due to diameter mismatch and global buckling due to centerline curvature mismatch. Local buckling, characterized by excess graft material buckling and wrinkle formation, increases with higher levels of oversizing, leading to a larger potential endoleak volume. Global buckling, where the endograft bends or deforms to conform to the centerline curvature of the artery, is observed to require a certain degree of oversizing to bridge the curvature mismatch. This study highlights the importance of considering both curvature and diameter mismatch in the design and clinical use of endografts. Understanding the mechanisms of endoleak formation can provide valuable insights for optimizing endograft design and surgical planning, leading to improved clinical outcomes in endovascular aortic procedures.

Bridging Stent-Graft Implantation in the Renal Artery During Complex Endovascular Aortic Procedures does not alter the Renal Sonographic Resistance Index

Abstract Background Ultrasound examination of the resistance index (RI) of both kidneys can provide evidence of renal artery stenosis. The extent to which the RI is changed after bridging stent-graft implantation due to altered flow characteristics is not known. Aims The aim of the study was to investigate the influence of renal bridging stent-grafts on the RI of the kidneys after fenestrated endovascular aortic repair (FEVAR). Methods Ultrasound examinations of the kidneys were conducted using a GE LOGIQ S7 XDclear ultrasound system (GE Medical Systems AG, Glattburg, Switzerland). The evaluation was performed according to SGUM 2D standard criteria. The RI was determined in all consecutive patients on the day before and after renal bridging stent-graft implantation. For this purpose, the kidneys were divided into 3 areas according to the standard protocol and 2 RI values were recorded per area by evaluating intrarenal arterial Doppler signals. Mean values were calculated and compared for each kidney. Results For 64 kidneys in 32 consecutive patients (73.9±7.8 years, 4 female, 28 male) treated with FEVAR and renal bridging stent–graft implantation pre- and postinterventional examinations were carried out. Sono-morphologically, the kidneys examined were inconspicuous (pre: size at least 107.1x52.4 mm, parenchymal margin 18.3 mm versus post: size at least 107.9x52.9 mm, parenchymal margin 18.6 mm, p&amp;gt;0.4). The arborization of the renal perfusion was preserved pre and post implantation. The RI did not differ before and after implantation (0.66±0.06 versus 0.67±0.07; p=0.10). None of the patients experienced severe impairment of renal function. Conclusion After successful implantation of a bridging stent-graft in a non-stenosed renal artery, there is no relevant change in the RI of the kidney. The RI seems therefore to be suitable for assessing renal perfusion after complex endovascular aortic therapy.

Isocentric fixed angle irradiation-based DRR: a novel approach to enhance x-ray and CT image registration.

Objective.Digitally reconstructed radiography (DRR) plays an important role in the registration of intraoperative x-ray and preoperative CT images. However, existing DRR algorithms often neglect the critical isocentric fixed angle irradiation (IFAI) principle in C-arm imaging, resulting in inaccurate simulation of x-ray images. This limitation degrades registration algorithms relying on DRR image libraries or employing DRR images (DRRs) to train neural network models. To address this issue, we propose a novel IFAI-based DRR method that accurately captures the true projection transformation during x-ray imaging of the human body.Approach.By strictly adhering to the IFAI principle and utilizing known parameters from intraoperative x-ray images paired with CT scans, our method successfully simulates the real projection transformation and generates DRRs that closely resemble actual x-ray images.Main result.Experimental results validate the effectiveness of our IFAI-based DRR method by successfully registering intraoperative x-ray images with preoperative CT images from multiple patients who underwent thoracic endovascular aortic procedures.Significance. The proposed IFAI-based DRR method enhances the quality of DRR images, significantly accelerates the construction of DRR image libraries, and thereby improves the performance of x-ray and CT image registration. Additionally, the method has the generality of registering CT and x-ray images generated by large C-arm devices.

Intraoperative Staff Radiation Exposure During Aortic Endovascular Procedures

The risk of radiation exposure in the surgical operating room (OR) and/or catheterization laboratory is now well established. Complex endovascular procedures often require multiple approaches and different positioning of the staff members around the patient, potentially increasing the levels of radiations exposure. Our goal was to evaluate the levels of radiation exposure of the members of the staff during endovascular aortic procedures in order to propose radioprotection optimization. We included 41 aortic endovascular procedures out of 114 procedures performed between January 12, 2014, and August 31, 2015, including 24 standard endovascular aortic aneurysm repair (EVAR), 7 EVAR with iliac branch (EVARib), 8 complex fenestrated/branched EVAR (F/B EVAR), and 2 thoracic EVAR (TEVAR). Procedures were performed in an OR equipped with a carbon fiber table and a mobile fluoroscopy C-arm. We collected the usual dosimetry data given by the C-arm as well as the patient's peak skin dose (PSD). In all staff members, radiation exposure was measured with thermoluminescent chip dosimeters placed on both temples, on posterior sides of both hands, and on both lower legs. PSD levels were low for EVAR because 24 patients had values below the reading threshold. PSD significantly increased with more complex procedures. Main operator (MO) received the higher level of irradiation on whole body, hands, and ankles. Eye lenses irradiation was higher on both assistant operators (AOs). Other members received low levels of irradiation. We found a high ranges of radiation exposure with a high risk of exposure for the AO, mainly for F/B EVAR and EVARib. Even if all personal protections are used, staff positioning is a major point that must be considered. If MO is supposed to be the most exposed to X-rays, specific conditions of positioning of the AO may be at risk of exposure.

Enhancing Arterial Closure in Endovascular Aortic Procedures: The Efficacy of Echo-Guided ProGlide Technique

Endovascular aortic surgery is increasingly becoming the standard treatment. Percutaneous access preclosing systems appear to be effective and notably the Proglide (PG). We aimed to prospectively assess the clinical effectiveness of combining ultrasound-guided femoral puncture with ultrasound-guided PG deployment. Our single-center study consecutively included patients managed at a tertiary center from May to September 2023, undergoing endovascular aortic surgery. The placement of PG was performed under ultrasound guidance. Preoperative patient characteristics were evaluated using preoperative computed tomography scans. Clinical and technical success were defined, respectively, as the ability to achieve complete hemostasis confirmed by ultrasound 48hr postprocedure and as the successful placement of a PG under ultrasound guidance contributing to final hemostasis. Twenty patients were included over a 6-month period, totaling 34 common femoral arteries (CFAs). Fourteen were male, with an average age of 72.8±8.2years. Among the 34 CFA, CFA had diameter of 12.05±2.4mm and a depth of 38.0±13.4mm. The mean introducer sheath diameter was 6.2±1.5mm with a sheath to femoral artery ratio of 0.54±0.18. Successful Proglide placement under ultrasound guidance was achieved in 100% of cases. No PG failure occurred. Clinical and technical success were, respectively, of 95% and 100%. One small pseudoaneurysm was observed at 48 hr treated medically. No CFA access reintervention was required. The technique of ultrasound-guided PG deployment in aortic surgery is a safe and effective method for achieving hemostasis. It effectively prevents PG failures at a lower cost.

Plug-Based Embolization Techniques of Aortic Side Branches during Standard and Complex Endovascular Aortic Repair.

Vascular plugs are an evolving family of vessel occluders providing a single-device embolization system for large, high-flow arteries. Nitinol mesh plugs and polytetrafluoroethylene membrane plugs are available in different configurations and sizes to occlude arteries from 3 to 20 mm in diameter. Possible applications during complex endovascular aortic procedures are aortic branch embolization to prevent endoleak or to gain an adequate landing zone, directional branch occlusion, and false lumen embolization in aortic dissection. Plugs are delivered through catheters or introducers, and their technical and clinical results are comparable to those of coil embolization. Plugs are more accurate than coils as repositionable devices, less prone to migration, and have fewer blooming artifacts on postoperative computed tomography imaging. Their main drawback is the need for larger delivery systems. This narrative review describes up-to-date techniques and technology for plug embolization in complex aortic repair.

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.

Intravascular Iliac Artery Lithotripsy to Facilitate Aortic Endograft Delivery: Midterm Results of a Dual-Center Experience.

To assess the feasibility and safety of intravascular lithotripsy (IVL) for enabling transfemoral abdominal (EVAR), thoracic (TEVAR), and thoracoabdominal (BEVAR) endovascular aneurysm repair in patients with narrow and calcified iliac arteries. Consecutive patients treated with IVL for severe calcified and narrowed iliac access before EVAR, TEVAR, or BEVAR between November 2020 and June 2022 were retrospectively evaluated. All anatomical iliac characteristics were acquired by multi-planar reconstruction of preoperative computed tomography angiography (CTA). The hostility of the vascular accesses was classified based on Peripheral Arterial Calcium Scoring System (PACSS) and calcified access severity score (CASS), a new score considering both anatomical (calcium grade and length, minimum lumen diameter [MLD], and tortuosity index) and aortic stent-graft (SG/MLD index) parameters. Primary endpoint was technical success defined as successful aortic endograft delivery and deployment without iliac rupture. Freedom from complications and primary patency were additionally analyzed. Twenty-eight iliac axes were treated with IVL (8 bilateral) in 20 patients (mean age 74.5±6.7 years) with a mean follow-up of 26.5±6.2 (range 17-36) months. Ten patients underwent EVAR: 3 TEVAR, and 7 BEVAR procedures. In 14 patients (70%), aneurysm disease was associated with symptomatic aorto-iliac occlusive disease (AIOD), with Rutherford class III to IV. The PACSS was grade IV in 89% of the cases and the CASS (mean 14±2) was grade III to IV in all cases. The stent-graft (SG) outer diameter (5.60±1.65 mm) was significantly larger by 50% than MLD (3.96±1.20 mm), with an SG/MLD index of 1.50±0.51 (p<0.001). Technical success was 100%. No dissection, rupture, or distal embolization occurred. One (3.4%) bail-out stenting was necessary as endoconduit after IVL treatment. One month CTA showed that postoperative luminal gain increased by 93% (p<0.001). An improvement of 2 Rutherford classes occurred in all AIOD patients with a primary patency of 100% at last follow-up. This study shows the safety and feasibility of IVL as a valuable option to treat narrow and calcified iliac arteries to facilitate endograft delivery. Further studies will be useful to confirm these results. In this article, the use of intravascular iliac artery lithotripsy to facilitate aortic endograft delivery is explored. The presence of iliac severe calcifications still represents a contraindication for aortic endovascular repair. Intravascular lithotripsy increases the feasibility and safety of endovascular aortic procedures, facilitating endograft delivery and reducing the risk of iliac rupture and/or dissections by improving vessel compliance and luminal gain. This novel vessel preparation could be an alternative to "paving and cracking" and/or iliac conduits. This study describes a new score to classify the severity of iliac calcifications, considering anatomical parameters and the profile of aortic endografts delivery system.

Safety and learning curve of percutaneous axillary artery access for complex endovascular aortic procedures: Presented at the plenary session of the 2022 Vascular Annual Meeting of the Society for Vascular Surgery, Boston, Massachusetts, June 15-18, 2022.

Safety and learning curve of percutaneous axillary artery access for complex endovascular aortic procedures: Presented at the plenary session of the 2022 Vascular Annual Meeting of the Society for Vascular Surgery, Boston, Massachusetts, June 15-18, 2022.

Accuracy and Sterilizability of In-House Printed Patient-Specific Aortic Model for Surgeon-Modified Stent Grafts-A Workflow Description for Emergency Aortic Endovascular Procedures.

Introduction: The use of 3D-printed aortic models for the creation of surgeon-modified endoprostheses represents a promising avenue in aortic surgery. By focusing on the potential impact of sterilization on model integrity and geometry, this report sheds light on the suitability of these models for creating customized endoprostheses. The study presented here aimed to investigate the safety and viability of 3D-printed aortic models in the context of sterilization processes and subsequent remodeling. Methods: The study involved the fabrication of 3D-printed aortic models using patient-specific imaging data and established additive manufacturing techniques. Five identical aortic models of the same patient were printed. Two models were subjected to sterilization and two to disinfection using commonly employed methods, and one model remained untreated. The models were checked by in-house quality control for deformation (heat map analyses) after the sterilization and disinfection processes. Three models (sterilized, disinfected, and untreated) were sent for ex-house (Lufthansa Technik, AG, Materials Technologies and Central Laboratory Services, Hamburg, Germany) evaluation and subsequent quantification of possible structural changes using advanced imaging and measurement technologies (macroscopic and SEM/EDX examinations). After sterilization and disinfection, each aortic model underwent sterility checks. Results: Based on macroscopic and SEM/EDX examinations, distinct evidence of material alterations attributed to a treatment process, such as a cleaning procedure, was not identified on the three implants. Comparative material analyses conducted via the EDX technique yield consistent results for all three implants. Disinfected and sterilized models tested negative for common pathogens. Conclusions: The evaluation of 3D-printed aortic models' safety after sterilization as well as their suitability for surgeon-modified endoprostheses is a critical step toward their clinical integration. By comprehensively assessing changes in model integrity and geometry after sterilization, this research has contributed to the broader understanding of the use of 3D-printed models for tailor-made endovascular solutions. As medical technologies continue to evolve, research endeavors such as this one can serve as a foundation for harnessing the full potential of 3D printing to advance patient-centered care in aortic surgery.

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.

National UK Survey of Radiation Doses During Endovascular Aortic Interventions

PurposeEndovascular aortic repair (EAR) interventions, endovascular abdominal aortic repair (EVAR) and thoracic endovascular aortic repair (TEVAR), are associated with significant radiation exposures. We aimed to investigate the radiation doses from real-world practice and propose diagnostic reference level (DRL) for the UK.Materials and MethodsRadiation data and essential demographics were retrospectively collected from 24 vascular and interventional radiology centres in the UK for all patients undergoing EAR—standard EVAR or complex, branched/fenestrated (BEVAR/FEVAR), and TEVAR—between 2018 and 2021. The data set was further categorised according to X-ray unit type, either fixed or mobile. The proposed national DRL is the 75th percentile of the collective medians for procedure KAP (kerma area product), cumulative air kerma (CAK), fluoroscopy KAP and CAK.ResultsData from 3712 endovascular aortic procedures were collected, including 2062 cases were standard EVAR, 906 cases of BEVAR/FEVAR and 509 cases of TEVAR. The majority of endovascular procedures (3477/3712) were performed on fixed X-ray units. The proposed DRL for KAP was 162 Gy cm2, 175 Gy cm2 and 266 Gy cm2 for standard EVAR, TEVAR and BEVAR/FEVAR, respectively.ConclusionThe development of DRLs is pertinent to EAR procedures as the first step to optimise the radiation risks to patients and staff while maintaining the highest patient care and paving the way for steps to reduce radiation exposures.

Safety and learning curve of percutaneous axillary artery access for complex endovascular aortic procedures

BackgroundPercutaneous axillary artery access is increasingly used for large-bore access during interventional vascular and cardiac procedures. The aim of this study was to evaluate the safety and learning curve of percutaneous axillary artery access in patients undergoing complex endovascular aortic repair (fenestrated and branched endovascular aneurysm repair [FBEVAR]) requiring large-bore upper extremity access and to discuss best practices for technique and complication management. MethodsOne-hundred forty-six patients undergoing large-bore percutaneous axillary artery access during FBEVAR in a prospective, nonrandomized, Investigational Device Exemption study between September 2017 and January 2023 were analyzed. Ultrasound guidance and micropuncture were used to access the second portion of the axillary artery and 2 Perclose Proglide or Prostyle devices (Abbott Vascular) were predeployed before the insertion of the large-bore sheath. Completion angiography was performed in all patients to verify hemostatic closure. Axillary artery patency was also assessed on follow-up computed tomography angiography. Patient-related, procedural, and postoperative variables were collected and analyzed. ResultsOne-hundred forty-five patients underwent successful percutaneous axillary artery access; 1 patient failed axillary access and alternative access was established. The left axillary artery was accessed in 115 patients (79%), and the right axillary artery was accessed in 30 patients (21%). The largest profile sheath was 14 F in 4 patients (2.8%), 12F in 133 patients (91.7%), and 8F in 8 patients (5.5%). Ten patients (6.9%) required covered stent placement (Viabahn, W. L. Gore & Associates) for failure to achieve hemostasis; there were no conversions to open surgical repair. Additional adverse events included transient upper extremity weakness in two patients (1.3%) and transient upper extremity paresthesias in two patients (1.3%). Three patients (2%) suffered postoperative strokes, including one unrelated hemorrhagic stroke and two possibly access-related embolic strokes. On follow-up, axillary artery patency was 100%. There was a trend toward decreased closure failure over time, with seven patients (10%) in the early cohort and three (4%) in the late cohort. There was a significant negative correlation between the cumulative complication rate and the cumulative experience. ConclusionsLarge-bore percutaneous axillary artery access provides safe upper extremity large-bore access during FBEVAR, achieving successful closure in >90% of patients with a low incidence of access-related complications. There was a trend toward better closure rates with increasing experience, suggesting a learning curve effect. Application of best practices including ultrasound guidance and angiography may ensure safe application of the technique of percutaneous large-bore axillary artery access.

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.

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.

Prophylactic cerebrospinal fluid drainage and spinal cord ischemia in thoracic and thoracoabdominal endovascular procedures: a systematic review and meta-analysis.

Spinal cord ischemia (SCI) is one of the most devastating complications of thoracic endovascular aortic repair (TEVAR). Prophylactic cerebrospinal fluid drainage (CSFD) has been shown to decrease the risk of SCI in open thoracic aortic procedures; however, its utility in TEVAR remains uncertain. This systematic review and meta-analysis aim to determine the role of prophylactic CSFD in preventing SCI in TEVAR. A literature search of five databases was performed and all studies published before September 2022 that reported SCI rates in TEVAR patients undergoing prophylactic CSFD were included. A random effects meta-analysis of means or proportions was performed for single-arm data. Odds ratios (ORs) with 95% confidence intervals (CIs) were reported for comparisons between groups. A total of 4,793 patients undergoing TEVAR from 40 studies were included. The mean age was 68.8 years and 70.9% of patients were male. The overall SCI rate was 3.5%, with a 1.3% rate of immediate SCI and a 1.9% rate of delayed SCI. There were no significant differences in SCI rates between prophylactic CSFD patients and non-drained patients. Routine CSFD did not have a significant impact on SCI rates compared to non-drained patients. There was an increased rate of transient SCI with selective CSFD compared to non-drained patients (OR 2.08; 95% CI: 1.06-4.08; P=0.03). The most common drain-related complication was spinal headache (4.3%). The major complication rate was 1.6%, of which epidural or spinal hematoma (0.9%) was the most common, followed by intracranial or subdural hemorrhage (0.8%) and paraparesis or paraplegia (0.8%). This study found no significant difference in SCI rates between prophylactic CSFD patients and their non-drained counterparts. CSFD is associated with a small but non-negligible risk of serious complications. Multi-center randomized controlled trials (RCTs) are warranted to help stratify the risk of both SCI and CSFD-related complications in patients undergoing endovascular aortic procedures.

Novel Technique for Intentional Occlusion of Directional Branches During Complex Endovascular Aortic Repair Using Microvascular Plugs.

To demonstrate the feasibility and outcomes of using the microvascular plug (MVP) for intentional occlusion of directional branches (DB) during complex endovascular aortic procedures. Two patients were treated with the off-the-shelf four-branched Zenith t-Branch thoracoabdominal stent-graft (Cook Medical, Bloomington, Ind). In both cases, the renal arteries (on one side in patient #1 and on both sides in patient #2, respectively) were occluded at time of index intervention. Preoperative planning included the intentional occlusion of each DB with one 7Q-MVP. Technical success was achieved in all cases and maintained at mid-term follow-up (12months and 36months, respectively). Use of the MVP appears to be feasible and effective for intentional occlusion of DB during complex endovascular aortic repair. This novel and simple technique may present some unique technical advantages, allowing precise placement of the device while avoiding extension using a bridging stent and DB cannulation with larger sheaths.