A Novel Electromagnetic Coil (EMAG) Fenestrated Stent-Graft for Rapid Cannulation to Reduce Use of Contrast Agent and Radiation Exposure During Fenestrated EVAR.
Aug 2026· Journal of Endovascular Therapy· pp.
15266028261471720
· 0 citations· 23 references
Medicine
TL;DR
The findings of this study demonstrate the feasibility of the EMAG system as a novel approach for assisting branch-vessel cannulation during fenestrated endovascular aortic repair, offering a promising approach to improve patient safety in an increasingly common procedure.
Abstract
Endovascular aortic repair (EVAR) has emerged as a popular option for minimally invasive treatment of abdominal and thoracic aortic aneurysms, offering advantages over traditional open surgical methods by reducing immediate postoperative morbidity and mortality. Although the endovascular repair option is attractive, it can potentially increase patient risks associated with x-ray exposure during the procedure, as significant levels of ionizing radiation are generated during preoperative diagnostic angiography, perioperative device placement, and lifelong follow-up imaging. For treatment of complex aortic aneurysms involving visceral vessels, radiation exposure during fenestrated stent-graft repair is typically double that of conventional unfenestrated stent-graft delivery and placement, which puts patients and clinicians at risk of reaching lifetime radiation limits and potentially developing cancer. To address this issue, a novel electromagnetic (EMAG) system has been developed and studied to potentially reduce radiation overexposure during the procedures by expediting a key step of the process, namely cannulation of fenestrations. The solenoid electromagnetic EMAG system embedded surrounding the ostia of the fenestrations attracts the magnetized tip of either a guidewire or catheter into a side branch, rapidly and selectively cannulating branch vessels in the aorta. The EMAG prototype was designed and fabricated with selective design requirements. A comparative study between the EMAG system and a standard guidewire demonstrated that the average time to cannulate with the EMAG system was 5.73 ± 2.67 seconds, which was significantly less than the average time taken to cannulate with the standard guidewire (34.37 ± 39.91 seconds, P < .01). In addition, the feasibility of the EMAG device was evaluated by characterizing its attraction force, dislodging force, and temperature rise. This device has the potential to reduce radiation exposure during EVAR procedures, offering a promising approach to improve patient safety in an increasingly common procedure.Clinical ImpactThe findings of this study demonstrate the feasibility of the EMAG system as a novel approach for assisting branch-vessel cannulation during fenestrated endovascular aortic repair. By advancing this technology through further preclinical and clinical studies, the EMAG system has the potential to improve workflow, enhance procedural consistency, reduce fluoroscopy dependence, and contribute to safer and more efficient complex endovascular interventions.
PURPOSE
Electrified wire in situ fenestration (EWISF) represents an effective off-the-shelf option in time-sensitive endovascular procedures. This article highlights the importance of radiofrequency energy delivery duration for successful catheter crossing with subsequent ballooning and bridging stent placement.
CASE REPORT
An 89-year-old man with symptomatic pararenal abdominal aortic aneurysm was transferred to our endovascular center. Given the patient's advanced age and the urgent clinical scenario, an endovascular approach was preferred. Pre-stenting of the stenotic left renal artery (LRA) was followed by intentional coverage of both renal arteries using a tubular aortic endograft with suprarenal fixation (Endurant). The right renal artery was revascularized using a bare metal stent (Visi-Pro) via the parallel technique, whereas the LRA was targeted with EWISF. Intraoperatively, catheter crossing after initial EWISF proved highly challenging. A repeat EWISF procedure with prolonged radiofrequency application was required to accomplish revascularization. Distal extension with a bifurcated endograft, appropriately sized limbs, and subsequent implantation of a physician-modified thoracic endograft, to manage insufficient overlap between the previously implanted endografts, completed the operation.
CONCLUSION
Electrified wire in situ fenestration is effective for endograft modification; prolonged energy delivery may be required to achieve catheter passage.Clinical ImpactThe electrified wire technique has emerged as a valuable alternative for in situ fenestration in urgent cases, enabling target vessel revascularization at low cost using readily available equipment. In a patient with a symptomatic pararenal aneurysm undergoing urgent endovascular repair, electrified wire in situ fenestration (EWISF) proved challenging. After intentional coverage of the renal artery ostium with a tubular aortic endograft, the initial EWISF attempt did not allow catheter passage through the endograft. A second attempt with prolonged electrical energy application ultimately enabled successful revascularization of the renal artery. Application duration may affect EWISF success, and acknowledgment of this parameter seems essential for enhanced technique reproducibility.
S. Iodice, George Apostolidis, Daour Yousef Al Sarhan et al.· Journal of Endovascular Ther...· 0 citations
F/B-EVAR guided by 3D simulation may allow for accurate planning of fenestration and branch positioning, potentially improving procedural success rate and suggesting a potential to enhance the quality of outcomes.
Yujing Zhang, Jing Wang, Cheng-Long Qu et al.· Therapeutic Advances in Card...· 0 citations
Abstract Background Endovascular aneurysm repair (EVAR) has become the preferred treatment for infrarenal abdominal aortic aneurysms (AAA), offering reduced morbidity and faster recovery compared with open surgery. However, patients with complex neck anatomy pose significant technical challenges, and current treatment approaches carry inherent risks. Learning from and summarizing experiences from these complex cases is crucial for advancing EVAR techniques. Case summary An 80-year-old female with a 10-year history of conservatively managed infrarenal AAA complained of intermittent abdominal pain for 1 week. Computed tomography angiogram (CTA) demonstrated a tortuous infrarenal AAA with a tapered neck. Aneurysmal dilatation and severe calcification of bilateral iliac arteries and tortuous aortoiliac access were also shown. EVAR was performed successfully using Gore Excluder C3 stent-grafts (W.L. Gore & Associates, Flagstaff, AZ, USA). During deployment, inadvertent forward displacement of the guidewire caused an iatrogenic abdominal aortic dissection above the left renal artery. The false lumen was immediately coil-embolized with five interlock coils, successfully excluding the dissection flap and restoring antegrade flow. The procedure was completed uneventfully, with the stent-graft well positioned, patent, and free of endoleak. Discussion The case highlights both the utility and risks of advanced EVAR techniques in complex anatomy. The wall-push technique, while useful for severe neck angulation, requires meticulous guidewire control and carries risk of vessel injury. Key preventive measures include continuous fluoroscopic monitoring, team communication, consideration of safety wires, and careful preoperative assessment. The learning curve for advanced techniques is steep, emphasizing the need for proper training, experience, and comprehensive preoperative planning using three-dimensional CTA reconstruction.
Introduction: Endovascular-first strategies for aortoiliac occlusive disease (AIOD) are standard, yet they carry risks of iatrogenic complications. Subintimal stent deployment is a rare but limb-threatening event that traditionally requires emergency open surgery. This report describes a successful endovascular bailout using a novel through-the-strut re-entry technique.
Case presentation: A 58-year-old male with diabetes and a 40 pack-year smoking history presented with rest pain and cyanosis of the right first toe (Rutherford 4). Imaging confirmed severe right common iliac artery (CIA) stenosis. During intervention, a 0.035” hydrophilic wire inadvertently created a subintimal dissection. A 7 – 57 mm balloon-expandable stent (Besmooth) was deployed within the false lumen, causing acute limb ischemia. The complication was managed by navigating a 5F JR catheter through the misplaced stent's struts to re-access the true lumen. After sequential balloon dilatation through the struts (4F to 7F), an 8 – 100 mm self-expanding Lifestent was deployed to re-line the artery, crushing the initial stent against the wall. Immediate blood flow was restored. The ankle-brachial index improved from 0.4 pre-procedure to 1.1 after intervention. At 6-month follow-up, the patient remained asymptomatic with a patent "stent-in-stent" complex on CTA.
Conclusion: Iatrogenic subintimal stent deployment can be successfully salvaged through the "through-the-strut" technique. This approach avoids the high morbidity of emergency open bypass in high-risk patients and provide an effective endovascular bailout strategy to restore true lumen perfusion and avoid emergency surgical conversion in selected patients..
T. A. Vo, Cong Tien Nguyen, Thời Hải Nguyên Nguyễn· Tạp chí Phẫu thuật Tim mạch...· 0 citations
Type 2 endoleak (T2EL) is the most common complication after endovascular aneurysm repair (EVAR), occurring in 10%–25% of patients. Although many T2ELs follow a benign course, persistent T2EL is associated with sac expansion, secondary endoleaks, rupture, and aneurysm-related mortality. Endovascular treatment is indicated in cases of progressive sac growth and is broadly divided into the transarterial approach and the direct sac puncture approach—the latter encompassing transabdominal, translumbar, and tran-scaval routes. Each approach has distinct technical advantages and limitations, and selection should be tailored to the source vessel of the endoleak, sac location, surrounding anatomy, and patient-related factors. Coils, N-butyl cyanoacrylate, and ethylene vinyl alcohol copolymer (Onyx) constitute the principal embolic agents, with liquid embolics showing improved durability over coils alone in recent comparative studies. Prophylactic embolization of the inferior mesenteric artery, lumbar arteries, or the aneurysm sac during EVAR has recently emerged as a promising preventive strategy. This review summarizes the current approaches, embolic materials, prophylactic strategies, and clinical outcomes of T2EL management from the perspective of the interventional radiologist.
J. Kwon· Korean Journal of Interventi...· 0 citations
Endovascular aneurysm repair (EVAR) has become a widely adopted treatment for abdominal aortic aneurysms, offering lower perioperative morbidity and mortality than open surgical repair. Nevertheless, long-term imaging surveillance remains essential because procedure-related complications may occur years after treatment. Among these, endoleaks represent the most frequent and clinically relevant finding, particularly Type II endoleaks, which are sustained by retrograde collateral perfusion and may be associated with persistent aneurysm sac filling and sac enlargement. Computed tomography angiography (CTA) remains the reference standard for anatomical assessment after EVAR, providing detailed evaluation of endograft integrity, aneurysm sac morphology, and vascular anatomy. However, repeated CTA examinations involve cumulative radiation exposure and iodinated contrast administration and may be limited in the detection of low-flow or intermittent endoleaks. Contrast-enhanced ultrasound (CEUS) provides real-time hemodynamic assessment, improves detection of slow-flow endoleaks, and avoids both ionizing radiation and nephrotoxic contrast agents. Nevertheless, CEUS may be affected by operator dependency and limited anatomical overview. CT–ultrasound fusion imaging combines pre-acquired CTA datasets with real-time ultrasound through spatial co-registration and probe tracking, enabling simultaneous evaluation of vascular anatomy and flow dynamics. This narrative review critically synthesizes current evidence regarding CTA, CEUS, and CT–ultrasound fusion imaging in post-EVAR surveillance, with particular emphasis on the incremental clinical value of fusion imaging beyond standalone CTA and CEUS. Particular attention is devoted to diagnostic performance, technical implementation, clinical applicability, current limitations, and future perspectives of CT–CEUS fusion imaging.
M. Montatore, Gianmichele Muscatella, R. Tupputi et al.· Radiation· 0 citations
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