Techniques and Devices in Neuroendovascular Procedures

Systematic reviews and meta-analyses in the cerebrovascular space: essential domains for readers

INTRODUCTION

Systematic Review and Meta-Analysis (SRMAs) in neurosurgery have significantly increased. With approximately 1 million patients affected by cerebrovascular disease annually, interpreting SRMAs necessitates a systematic approach. The objective of this review is to identify and describe four essential domains for SRMA interpretation.

METHODS

This review outlines the necessities of reviewing existing literature and methodological frameworks essential for interpreting cerebrovascular neurosurgery SRMAs. Each domain is to accurately assess study design variations, heterogeneity assessment methods, outcome comparability strategies, and the impact of technological advancements and time bias on study outcomes.

RESULTS

Study design evaluation distinguishes between randomized controlled trials (RCTs) and non-randomized studies. RCTs provide high internal validity, but as seen in the ARUBA trial, can contain internal flaws that necessitate a deeper understanding before application to clinical practices. Non-randomized studies offer valuable real-world insights. A heterogeneity assessment involves readers and writers accurately using forest plots, Cochrane's Q test, Higgins I² statistics, subgroup analysis, and meta-regressions to understand a study's clinical findings. The expertise thresholds, as in the NASCET trial, significantly impact a study's external validity. Strategies such as the GRADE approach can assist in managing diverse outcome measures. Technological advancements, particularly in endovascular procedures and SRS, influence the accuracy of comparing studies across periods, and thus swiftly outdate older studies, lowering the applicability of SRMAs.

CONCLUSION

Effective interpretation of cerebrovascular neurosurgery SRMAs requires attention to study design, heterogeneity, outcome comparability, and technological advancements. These domains collectively enable evidence-based clinical decision-making and optimized patient care in a dynamic field.

A new set of eyes: development of a novel microangioscope for neurointerventional surgery

BACKGROUND

Endovascular technological advances have revolutionized the field of neurovascular surgery and have become the mainstay of treatment for many cerebrovascular pathologies. Digital subtraction angiography (DSA) is the 'gold standard' for visualization of the vasculature and deployment of endovascular devices. Nonetheless, with recent technological advances in optics, angioscopy has emerged as a potentially important adjunct to DSA. Angioscopy can offer direct visualization of the intracranial vasculature, and direct observation and inspection of device deployment. However, previous iterations of this technology have not been sufficiently miniaturized or practical for modern neurointerventional practice.

OBJECTIVE

To describe the evolution, development, and design of a microangioscope that offers both high-quality direct visualization and the miniaturization necessary to navigate in the small intracranial vessels and provide examples of its potential applications in the diagnosis and treatment of cerebrovascular pathologies using an in vivo porcine model.

METHODS

In this proof-of-concept study we introduce a novel microangioscope, designed from coherent fiber bundle technology. The microangioscope is smaller than any previously described angioscope, at 1.7 F, while maintaining high-resolution images. A porcine model is used to demonstrate the resolution of the images in vivo.

RESULTS

Video recordings of the microangioscope show the versatility of the camera mounted on different microcatheters and its ability to navigate external carotid artery branches. The microangioscope is also shown to be able to resolve the subtle differences between red and white thrombi in a porcine model.

CONCLUSION

A new microangioscope, based on miniaturized fiber optic technology, offers a potentially revolutionary way to visualize the intracranial vascular space.

Vertebro-basilar junction aneurysms: a single centre experience and meta-analysis of endovascular treatments

Vascular lesions of the vertebrobasilar junction (VBJ) are challenging in neurosurgical practice, and their gold-standard therapy is still under debate. We describe the operative strategies currently in use for the management of these complex vascular lesions and discuss their rationale in a literature meta-analysis and single centre blinded retrospective study. The single centre study included a review of initial presentation, angiographic features and clinical outcome (with modified Rankin Scale [mRS] scores) over a long-term follow-up. In our series, small aneurysms were effectively treated by endosaccular coil embolization, whereas a strategy including flow-diverter devices combined with endosaccular coil embolization was the option of choice in large and giant aneurysms, leading to satisfactory outcomes in most cases. Our Medline review showed that endovascular treatment was chosen in most VBJ cases, whereas the microsurgical option was assigned to only a few cases. Among the endovascular treatments, the most common techniques used for the treatment of VBJ aneurysms were: coiling, stent-assisted coiling and flow diversion. Our study highlights that aneurysm morphology, location and patient-specific angio-architecture are key factors to be considered in the management of VBJ aneurysms. Most case series, including our own, show that parent artery reconstruction using a flow-diverter device is a feasible and successful technique in some cases of giant and complex aneurysms (especially those involving the lower third of the basilar artery) while a "sit back, wait and see" approach may represent the safest and most reasonable option.

Superselective ophthalmic artery infusion of melphalan for intraocular retinoblastoma: preliminary results from 140 treatments

PURPOSE

To report our experience in superselective ophthalmic artery infusion of melphalan (SOAIM) for intraocular retinoblastoma.

METHODS

  From June 2008 to October 2010, 38 patients (18 women, 20 men; age range at first treatment, 7 months to 22 years) with 41 eyes with retinoblastoma were scheduled for SOAIM, for 17 newly diagnosed retinoblastomas Tumour, Node and Metastasis (TNM) 7th Edition 1a (n = 1), 1b (n = 1), 2a (n = 7), 2b (n = 4) and 3a (n = 4) and 24 retinoblastomas with partial remission/relapse TNM 7th Edition 1b (n = 13), 2a (n = 1) and 2b (n = 10). Eight patients (ten eyes) have been treated by SOAIM alone. Follow-up was 6-27 months in 28 patients (30 eyes).

RESULTS

Ophthalmic artery cannulation failed in two patients. Thirty-six patients underwent 140 treatments by internal (n = 112) or external (n = 28) carotid arteries. No major procedural complications occurred. Two patients have been lost to follow-up. Remaining 34 patients (37 eyes) had no metastatic disease. Four patients suffered permanent ocular complications: chorioretinal dystrophy (n = 2), ptosis (n = 1) and strabismus/exotropia (n = 1). Eight (22%) eyes in eight (24%) patients underwent enucleation: 7/16 (43%) newly diagnosed retinoblastomas and 1/22 (4.5%) retinoblastomas undergoing partial remission/relapse. For all treated eyes, Kaplan-Meier eye enucleation-free rates (K-M) were 85.4% (95% CI, 73.3-97.5%), 74.4% (95% CI, 57-91.8%) and still stable at 6, 12 months and 2 years, respectively. For eyes with partial remission/relapse, and eyes at presentation, K-M at 2 years were 95.5% (95% CI, 86.9-100%) and 45.6% (95% CI, 16.6-74.6%), respectively.

CONCLUSION

Superselective ophthalmic artery infusion of melphalan was safe and powerful, especially following other therapies. Superselective ophthalmic artery infusion of melphalan should be added to focal therapies spectrum. In selected cases, melphalan should be combined with other chemotherapeutic agents.

Use of a new double-lumen balloon catheter for single-catheter balloon-assisted coil embolization of intracranial aneurysms: technical note

BACKGROUND

The prevalence of intracranial aneurysms is approximately 2% with an annual rupture rate of 0.7%.

OBJECTIVE

We describe our initial feasibility experience using a new double-lumen balloon catheter for single-catheter balloon-assisted coil embolization of wide-neck intracranial aneurysms.

METHODS

Two patients with large wide-neck intracranial aneurysms were referred for endovascular therapy. Endovascular treatment in the form of coil embolization alone was not feasible given the angioarchitecture of the aneurysms. Balloon-assisted coil embolization was planned.

RESULTS

The patients underwent balloon-assisted coil embolization using the Ascent double-lumen balloon catheter (Micrus, San Jose, California). The balloon portion of the catheter was placed into the proximal neck of the aneurysm. The balloon was inflated and coil embolization performed through the inner lumen of the catheter. There were no procedural complications.

CONCLUSION

Both aneurysms were successfully coiled by using the Ascent balloon occlusion catheter. The single-catheter balloon-assisted coil embolization technique can be performed safely and effectively with the Ascent double-lumen balloon catheter.