Use of the triple coaxial (triaxial) microcatheter system in superselective arterial embolisation for complex interventional cases: an initial experience with the system

Thin-Film-Based Optical Fiber Interferometric Sensor on the Fiber Tip for Endovascular Surgical Procedures

OBJECTIVE

Endovascular surgery requires accurate measurement of parameters such as pressure, temperature, and biomarkers within vessels for real-time tissue response monitoring and ensuring targeted therapeutic interventions. However, the availability of small tip-based sensors capable of precise application, for example, navigating an aneurysm's lumen, is limited. With their capabilities for real-time analysis, flexibility, and biocompatibility, optical fiber sensors (OFS) hold promise in addressing this need. This proof-of-concept study investigates the feasibility of OFS in endovascular surgery scenarios.

METHODS

The sensor is based on a single-mode silica fiber with an interferometric forward-facing thin-film tip. The thin-film materials may be tailored for detecting various physical parameters and, when functionalized, also specific analytes. Materials applied in this sensor are thin metal oxides deposited using magnetron sputtering. A full-scale 3D-printed vascular model was employed to simulate endovascular setup.

RESULTS

The experiments showed the high mechanical robustness of the approach, i.e., the sensor maintained functionality while being maneuvered through the endovascular model. The forward-facing tip remained intact and worked adequately, ensuring consistent and stable readouts. Moreover, the fiber showed sufficient flexibility, with no significant bending loss observed during simulations. Finally, the performance of the OFS in bovine serum samples was assessed. The sensor performed well in serum, and the results suggest that low-concentration serum may be used to reduce nonspecific surface interactions.

CONCLUSION

Overall, this OFS system offers a promising solution for endovascular surgery and other biomedical applications, allowing for precise and on-the-spot analysis.

SIGNIFICANCE

Our study pioneers the feasibility of thin-film interferometric label-free OFS with a forward-facing sensitive area for sensing during endovascular procedures.

Triple coaxial microcatheter for preoperative transcatheter arterial embolization in bone and soft tissue tumors

BACKGROUND

Preoperative transcatheter arterial embolization (P-TAE) is a procedure designed to reduce intraoperative blood loss (IBL) and support the performance of surgery for bone and soft tissue tumors (BSTT).

PURPOSE

To develop a new P-TAE technique using a triaxial microcatheter system (TMCS) that maintains normal tissue circulation while embolizing only the feeding artery of BSTT and to investigate the safety and efficacy of P-TAE with TMCS.

MATERIAL AND METHODS

A total of 34 cases of BSTT in the whole body (25 men, nine women; mean age = 74.85 ± 11.32 years) were included between 1 April 2014 and 30 June 2024. We evaluated technical and clinical outcomes, P-TAE techniques, complications, and patient characteristics.

RESULTS

Bone metastasis of renal cell carcinoma (n = 11) was the most frequent diagnosis. P-TAEs using TMCS were performed with technical success (97.05%) and clinical success (88.23%), demonstrating a high selectivity rate to the feeding artery of 97.14%. The mean IBL was 792.70 ± 1285.61 mL (median = 370 mL; range = 50-6935 mL). All surgeries were performed successfully after P-TAE.

CONCLUSION

P-TAE plays an important role in the presurgical operation of BSTT. The use of TMCS offers high selectivity, trackability, and crossability in the P-TAE procedure, enhancing the clinical efficacy of P-TAE.

3-Fr steerable microcatheter system via the upper limb artery in RADPLAT for right maxillary cancer

BACKGROUND

To evaluate the efficacy of a catheter system using a 3-Fr sheath with a steerable microcatheter through right upper limb artery access for superselective intra-arterial cisplatin infusion and concomitant radiotherapy (RADPLAT) to treat right maxillary sinus squamous cell carcinoma (MS-SCC).

MATERIAL AND METHODS

We retrospectively studied 46 sessions in eight patients treated between November 2020 and February 2023 using the catheter system briefly described below. A 3-Fr sheath was inserted into the distal radial, conventional radial, or brachial arteries. A coaxial catheter system with a 2.9-Fr steerable microcatheter and a 1.9-Fr microcatheter was advanced into the brachiocephalic artery. The right common carotid artery was selected by bending the tip of the steerable microcatheter. Coil embolization and intra-arterial cisplatin infusion after selecting each external carotid artery branch were achieved using this catheter system.

RESULTS

Cisplatin infusion and coil embolization were successful in all sessions. Arterial occlusion at the sheath insertion sites was found in 29.4% (5/17) of the distal radial arteries and 33.3% (3/9) of the conventional radial arteries. No other major complications were observed during the procedure.

CONCLUSION

Using a 3-Fr catheter system with a steerable microcatheter through right upper limb artery access is a feasible method for RADPLAT in treating right MS-SCC.

Chronological Changes in Embolization for Cerebral Arteriovenous Malformations: Impact of Endovascular Treatment Device Advancements

Objective

Although embolization of cerebral arteriovenous malformations (AVM) is widely performed as an adjunctive therapy before microsurgery or radiosurgery, there is no high-level evidence to ascertain its effectiveness. However, the technology for endovascular devices has improved. Therefore, this study aimed to identify the chronological changes in AVM embolization due to advances in endovascular treatment devices.

Methods

This retrospective study included 24 patients who underwent 31 embolization procedures between January 2018 and August 2023. Embolization plus microsurgery, embolization plus radiosurgery, and embolization alone were performed in 15 (62.5%) patients and 21 embolization procedures, 2 (8.3%) patients and 2 procedures, and 7 (29.2%) patients and 8 procedures, respectively. We assessed chronological changes in endovascular treatment devices and evaluated clinical outcomes (ideal position of microcatheter, vessel perforations, symptomatic complications) from January 2018 to December 2020 and from January 2021 to August 2023 based on the chronological changes in endovascular treatment devices.

Results

Intermediate catheters were employed in 29 (93.5%) procedures. Brands of intermediate catheters and microcatheters significantly changed around 2021. No differences were observed in the embolic materials. The ideal position of the microcatheter was achieved significantly more in 2021-2023 than in 2018-2020 (72.1% vs. 48.4%, p = 0.04). Vessel perforation by microcatheters in 2018-2020 and 2021-2023 occurred in 3 (18.8%) and 1 (6.7%) procedures (p = 0.32), respectively. Symptomatic complications in 2018-2020 and 2021-2023 occurred in 3 (18.8%) and 0 (p = 0.08) procedures, respectively. Complete obliteration was achieved in 18 of 24 patients (75.0%). Favorable clinical outcomes (modified Rankin Scale score 0-2) were observed in 20 of 24 (83.3%) patients at the final follow-up.

Conclusion

The advancement in endovascular devices for AVM has enabled effective and safe embolization, potentially enhancing the outcomes of microsurgical interventions.

Enhancing precision in vascular embolization: evaluating the effectiveness of the intentional early detachment technique with detachable coils in complex cases

BACKGROUND

This study aimed to assess the effectiveness and versatility of an intentional early detachment technique with detachable coils in addressing challenging vascular embolization scenarios. This novel approach aims to provide an alternative method for achieving precise coil placement when standard methods of detachable coil placement are ineffective owing to vascular anatomy or limited available equipment.

MATERIALS AND METHODS

This retrospective study included 11 patients (nine males and two females; median age, 77 years) who underwent embolization procedures between October 2021 and December 2023 using the intentional early detachment technique through 1.6-Fr or 1.3-Fr microcatheters. In this technique, detachable coils were intentionally detached within the microcatheter and placed through saline flushing. The technique's technical success, complications, and clinical success were evaluated.

RESULTS

The technique was applied in three distinct scenarios: tortuous vascular anatomy (four cases), inadequate system backup (three cases), and 1.3-Fr microcatheter use (four cases). The technical and clinical success rates were 100%. No complications were observed, and no cases of coil migration or malpositioning.

CONCLUSION

The intentional early detachment technique is valuable for interventional radiologists and offers a solution for challenging vascular embolization scenarios. Its application is limited to specific circumstances; however, it can significantly enhance coil placement in complex cases, thereby contributing to improved patient care.

Endovascular Applications for the Management of High-Grade Gliomas in the Modern Era

High-grade gliomas (HGGs) have a poor prognosis and are difficult to treat. This review examines the evolving landscape of endovascular therapies for HGGs. Recent advances in endovascular catheter technology and delivery methods allow for super-selective intra-arterial cerebral infusion (SSIACI) with increasing precision. This treatment modality may offer the ability to deliver anti-tumoral therapies directly to tumor regions while minimizing systemic toxicity. However, challenges persist, including blood-brain barrier (BBB) penetration, hemodynamic complexities, and drug-tumor residence time. Innovative adjunct techniques, such as focused ultrasound (FUS) and hyperosmotic disruption, may facilitate BBB disruption and enhance drug penetration. However, hemodynamic factors that limit drug residence time remain a limitation. Expanding therapeutic options beyond chemotherapy, including radiotherapy and immunobiologics, may motivate future investigations. While preclinical and clinical studies demonstrate moderate efficacy, larger randomized trials are needed to validate the clinical benefits. Additionally, future directions may involve endovascular sampling for peri-tumoral surveillance; changes in drug formulations to prolong residence time; and the exploration of non-pharmaceutical therapies, like radioembolization and photodynamic therapy. Endovascular strategies hold immense potential in reshaping HGG treatment paradigms, offering targeted and minimally invasive approaches. However, overcoming technical challenges and validating clinical efficacy remain paramount for translating these advancements into clinical care.

Transarterial Embolization of Type 2 Endoleak Post Thoracic Endovascular Aortic Repair (TEVAR) Using a Triaxial System With a 1.3-F Microcatheter: A Case Report

Although transarterial embolization is recognized as a treatment for type 2 endoleaks, it can occasionally be challenging. We report the case of an 86-year-old man who presented with an enlarging thoracoabdominal aortic aneurysm following thoracic endovascular aortic repair. Using a triaxial system with a 1.3-F microcatheter, transarterial embolization of a type 2 endoleak was successfully performed through a long and tortuous arterial route comprising the thoracodorsal and ninth intercostal arteries. The postoperative clinical course was uneventful, and computed tomography obtained six days later showed no endoleak in the thoracoabdominal aortic aneurysm. This case suggests the usefulness of a triaxial system with a 1.3-F microcatheter for transarterial embolization of type 2 endoleaks.