Treatment Outcome of Intracranial Tumor Embolization in Japan: Japanese Registry of NeuroEndovascular Therapy 3 (JR-NET3)

Evaluating the effectiveness of preoperative embolization for meningioma with pial feeders: Analysis of perfusion magnetic resonance imaging

Background and purposeMeningiomas often contain a pial supply, and devascularization through preoperative transarterial embolization (TAE) is useful. However, the efficacy indicators of TAE for meningiomas with pial feeders remain unclear owing to their challenging quantification. Therefore, we propose a practical and quantitative intratumoral cerebral blood volume (CBV) from the pial supply, called pial-nCBV. This study aimed to identify the efficacy indicators of TAE against meningiomas in pial feeders using pial-nCBV.Materials and methodsBetween 2015 and 2021, 25 patients who underwent preoperative TAE and perfusion magnetic resonance imaging (MRI) for meningiomas with pial feeders were included in the study. We set 5 mm diameter round Region Of Interests as many as possible within the tumor at the border with the brain parenchyma, and calculated the intratumoral CBV from pial supply. The reduction rate was defined as primary outcome, termed Δ pial-nCBV. Additionally, we collected data on the injection behavior of the n-Butyl-Cyanoacrylate (n-BCA), including intratumoral embolization (IE) and feeder occlusion. We then analyzed the association between each variable and Δ pial-nCBV.ResultsThe median Δ pial-nCBV was 25%. The n-BCA was applied in 22 (88%) cases, of which nine (36%) cases were injected into pial feeders. The use of n-BCA (p = .037), treatment with pial feeders (p = .002), and IE in meningeal feeders (p = .049) were associated with an increase in Δ pial-nCBV.ConclusionWe proposed a practical indicator, pial-nCBV, and increasing Δ pial-nCBV was associated with treating pial feeder using n-BCA.

Volume Reduction Effect of Preoperative Embolization of Only the Feeding Arteries from the External Carotid Artery on Vestibular Schwannomas

BACKGROUND

Although there are many reports on the efficacy of preoperative embolization for meningioma, such as a reduction in intraoperative blood loss, its efficacy for vestibular schwannoma remains unclear. Feeding arteries of vestibular schwannomas include branches from the anterior inferior cerebellar artery and internal carotid artery, in addition to the branches from the external carotid artery (ECA). However, it has been reported that the embolization of feeding arteries from the anterior inferior cerebellar artery and the internal carotid artery has a high risk of complications. Therefore, we retrospectively analyzed the effects of preoperative embolization of only the feeding arteries from the ECA for vestibular schwannomas, particularly regarding its volume reduction effect.

METHODS

Of the 805 patients with vestibular schwannoma who underwent tumor removal at our department between September 2013 and March 2022, a total of 15 patients who underwent preoperative embolization of only the feeding arteries from the ECA were analyzed. Tumor volume was measured based on contrast-enhanced T1-weighted imaging, and the effects of preoperative embolization on tumor volume reduction were analyzed.

RESULTS

Tumor volumes before and after embolization were 16.4 ± 9.2 mL and 14.1 ± 9.6 mL, respectively, indicating a volume reduction effect of 15.3 ± 10.3% (P < 0.001). The mean time from embolization to contrast-enhanced T1-weighted imaging was 5.1 ± 3.0 days.

CONCLUSIONS

Preoperative embolization of only the feeding arteries from the ECA may be an effective adjunctive treatment for vestibular schwannomas, given the significant volume reduction effect achieved within several days after embolization, in addition to reducing intraoperative blood loss.

Embosphere Size Selection and Dilution Rate in Preoperative Tumor Embolization of the External Carotid Artery System Using a Small-diameter Catheter

The widespread adoption of preoperative embolization in highly vascularized brain tumors often involves the frequent use of Embosphere (Merit Medical Systems, South Jordan, Utah, USA). Nevertheless, inconsistency in size selection and dilution rates across different institutions requires comprehensive examination. This study explored the appropriate size and dilution rate of Embosphere microspheres. To assess catheter occlusion and Embosphere breakage, various dilutions (4-, 10-, 20-, 30-, and 60-fold) of Embosphere 300-500 and 500-700 μm were injected into the catheter in vitro. Results indicated that 20-fold or higher dilutions of Embosphere 300-500 μm and 30-fold or higher dilutions of Embosphere 500-700 μm showed no occlusion of the Excelsior SL-10 microcatheter (Stryker, Fremont, CA, USA) or Embosphere breakage. For embolization, to reduce the risk of Excelsior SL-10 occlusion further, a 30-fold dilution of Embosphere 300-500 μm and a 60-fold dilution of Embosphere 500-700 μm were employed. For 195 blood vessels in 107 patients (84 with meningioma and 23 with schwannoma), embolization was carried out using a 30-fold dilution of Embosphere 300-500 μm when the provocative test was negative and a 60-fold dilution of Embosphere 500-700 μm when the test was positive or when there was a risk of migration into neurotrophic vessels. Contrast-enhanced magnetic resonance imaging after embolization revealed a reduced enhancement effect in 69.1% of cases. Embolization using a 30-fold dilution of Embosphere 300-500 μm and a 60-fold dilution of Embosphere 500-700 μm with an Excelsior SL-10 catheter is safe and satisfactory, which minimizes microcatheter occlusion.

NBCA: Basic Knowledge

Various types of embolic substances are used in endovascular therapy, and understanding their characteristics, including shape and kinetics, is essential for proper use. Cyanoacrylate is a typical liquid embolization agent that can be applied to many cerebral neurovascular lesions. It is injected as a mixture with ethiodized oil to provide radiopacity and regulate the polymerization rate. This review describes the characteristics, action mechanisms, techniques of use, and potential pitfalls of using cyanoacrylate-ethiodized oil mixtures for embolization.

Preoperative Embolization of Brain Tumors Using a Provocative Test: Evaluating the Safety and Efficacy of Embolization of Test-Positive Vessels

PURPOSE

The embolization of vessels potentially involved in the vasa nervorum during brain tumor embolization is often a non-aggressive procedure. In this study, we aimed to investigate the safety and efficacy of embolization of vessels with positive provocative test results.

METHODS

Embosphere (Merit Medical Systems, South Jordan, Utah, USA) was the embolization material of choice. A provocative test was performed using 30 mg of 1% lidocaine, with a positive result if neurological symptoms appeared. A size of 500-700 µm was used for positive results and 300-500 µm for negative results. Embolization was performed five to seven days before resection, and contrast-enhanced MRI was performed three to five days after embolization to assess the embolic status.

RESULTS

Provocative tests were performed on 61 vessels from 55 patients. A total of 36 vessels (59.0%) were positive, and 25 vessels were negative. The petrosal branch of the middle meningeal artery and the neuro-meningeal branch of the ascending pharyngeal artery showed particularly high positivity rates (91.7% and 76.5%, respectively). Three patients (8.3%) out of the 36 who underwent embolization of the positive vessels had neurological symptoms after embolization; two had symptoms similar to those observed in the provocative test, and one had different symptoms. All symptoms were mild and transient. The postoperative contrast-enhanced MRI showed that the enhancing effect was attenuated in 18 of the 30 patients (60%) with provocative test-positive vessels.

CONCLUSION

Embolization of provocative test-positive vessels can be performed safely and effectively with a larger Embosphere (500-700 μm).

Embolic Material Migration as the Predominant Contributing Factor to Prognostic Deterioration Following Combined Tumor Resection and Preoperative Embolization

Introduction Preoperative embolization can potentially facilitate surgical resection of challenging tumors in the intracranial and facial regions; however, its clinical efficacy remains controversial, mainly due to potential morbidity risks. We explored negative factors of the combined treatment of preoperative embolization and tumor resection that affect neurological prognosis. Method This retrospective study used clinical data from 132 consecutive tumors that underwent combined treatment at multiple facilities between January 2016 and May 2021. Basic patient information, tumor characteristics, and treatment details were assessed to identify predictors of deterioration as measured using the modified Rankin scale (mRS) score at three months post-treatment. Results Among the 126 eligible combined treatments, a deterioration in the postoperative mRS score was observed in 19/126 (15.1%). Complications related to embolization and tumor resection occurred in 8/126 (6.3%) and 19/125 (15.2%) of procedures, respectively. Multivariate analyses indicated significant associations between migration of embolic material (adjusted odds ratio 13.80; 95% confidence interval 1.25-152.52; p=0.03), elevated intraoperative blood loss (p=0.04), and deterioration of postoperative mRS score. Embolic material migration was identified as the primary prognostic factor for the deterioration of score. An analysis of 192 procedures, excluding those that exclusively used coils, identified embolization targeting the accessory meningeal artery (p=0.046) and the third segment of the internal maxillary artery (p=0.03) as a risk factor for embolic material migration. Conclusions Embolic material migration is the predominant factor associated with declining neurological outcome that persists into the chronic phase after combined treatment. Given that preoperative embolization is a supplementary treatment option, a thorough understanding of vascular anatomy and striving safe procedure are critical.

Comparison of outcomes with/without preoperative embolization for meningiomas with diluted N-butyl-2-cyanoacrylate

BACKGROUND

Preoperative embolization for meningiomas is controversial regarding its effectiveness in reducing intraoperative blood loss and operative time. In contrast, some reports have documented improved surgical outcomes in large meningiomas. In this study, we retrospectively compared the outcomes of craniotomy for meningiomas with/without preoperative embolization with diluted N-butyl-2-cyanoacrylate (NBCA) primarily in a single institution.

METHODS

Data (World Health Organization grade, Simpson grade, maximum tumor diameter, intraoperative bleeding, operative time, history of hypertension, and time from embolization to craniotomy) of patients with initial intracranial meningiomas were compared with or without preoperative embolization from January 2015 to April 2022.

RESULTS

The embolization group consisted of 56 patients and the nonembolization group included 76 patients. Diluted NBCA (13% concentration for all patients) was used in 51 of 56 patients (91.1%) who underwent transarterial embolization. Permanent neurological complications occurred in 2 (3.6%) patients. Intraoperative bleeding was significantly lower in the embolization group for a maximum tumor diameter ≥40 mm (155 vs. 305 ml, respectively, p < 0.01). In the nonembolization group, for a maximum tumor diameter ≥30 mm, patients with hypertension had more intraoperative bleeding than non-hypertensive ones.

CONCLUSIONS

Despite its limitations, the present results showed that, under certain conditions, preoperative embolization for intracranial meningiomas caused less intraoperative bleeding. The safety of treatment was comparable with that reported in the Japan Registry of NeuroEndovascular Therapy 3 (JR-NET3) with a complication rate of 3.7% for preoperative embolization of meningiomas, despite the treatment focused on the liquid embolization material.

Assessing the efficacy and safety of hemangioblastoma embolization: A comprehensive systematic review and meta-analysis

BACKGROUND

Hemangioblastomas (HBs) are highly vascular tumors linked to substantial morbidity and mortality. Recently, interventional neuroradiology has evolved rapidly, spurring interest in preoperative embolization as a possible HB treatment.

PURPOSE

This study evaluates the effectiveness and safety of preoperative embolization in managing HB.

METHODS

Adhering to PRISMA guidelines, this meta-analysis considered randomized and nonrandomized studies meeting specific criteria, encompassing intracranial HB and preoperative embolization. Primary outcomes were preoperative embolization efficacy and safety. Complications were classified as major (cerebellar ischemia, ischemic strokes, intratumoral hemorrhage, subarachnoid hemorrhage) and minor (transient nystagmus, slight facial nerve palsy, nausea, transient dysarthria, hemiparesis, hemisensory impairment, thrombotic complications, extravasation).

RESULTS

Thirteen studies involving 166 patients with preoperative embolization before HB resection were included. Two studies using the Glasgow Outcome Scale (GOS) showed 5 patients with good recovery, 6 with moderate disability, and 3 with severe disability. Major complications occurred in 1% (95% CI: 0% to 3%), and minor complications occurred in 1% (95% CI: 0% to 4%). Intraoperative blood loss during resection was estimated at 464.29 ml (95% CI: 350.63 ml to 614.80 ml).

CONCLUSION

Preoperative embolization holds promise in reducing intraoperative bleeding risk in neurosurgical intracranial HB treatment, primarily due to its low complication rates. Nonetheless, additional research and larger-scale studies are essential to establish its long-term efficacy and safety. These findings highlight preoperative embolization as a valuable tool for HB management, potentially enhancing future patient outcomes.

Preoperative tumor embolization prolongs time to recurrence of meningiomas: a retrospective propensity-matched analysis

BACKGROUND

Meningiomas are often embolized preoperatively to reduce intraoperative blood loss and facilitate tumor resection. However, the procedure is controversial and its effects have not yet been reported. We evaluated preoperative embolization for meningiomas and its effect on postoperative outcome and recurrence.

METHODS

We retrospectively reviewed the medical records of 186 patients with WHO grade I meningiomas who underwent surgical treatment at our hospital between January 2010 and December 2020. We used propensity score matching to generate embolization and no-embolization groups (42 patients each) to examine embolization effects.

RESULTS

Preoperative embolization was performed in 71 patients (38.2%). In the propensity-matched analysis, the embolization group showed favorable recurrence-free survival (RFS) (mean 49.4 vs 24.1 months; Wilcoxon p=0.049). The embolization group had significantly less intraoperative blood loss (178±203 mL vs 221±165 mL; p=0.009) and shorter operation time (5.6±2.0 hours vs 6.8±2.8 hours; p=0.036). There were no significant differences in Simpson grade IV resection (33.3% vs 28.6%; p=0.637) or overall perioperative complications (21.4% vs 11.9%; p=0.241). Tumor embolization prolonged RFS in a subanalysis of cases who experienced recurrence (n=39) among the overall cases before variable control (mean RFS 33.2 vs 16.0 months; log-rank p=0.003).

CONCLUSIONS

After controlling for variables, preoperative embolization for meningioma did not improve the Simpson grade or patient outcomes. However, it might have effects outside of surgical outcomes by prolonging RFS without increasing complications.

Safety of pediatric cerebral angiography

OBJECTIVE

Catheter-based cerebral angiography is commonly used for neurovascular diagnosis in children. In this work, the authors aimed to quantify the complication rate of cerebral angiography in children, characterize these complications, and identify risk factors for complications.

METHODS

Relevant clinical data were retrospectively obtained for 587 consecutive cerebral angiography procedures performed in 390 children from March 2002 to March 2020. Complications were categorized as neurological or nonneurological, and severity was graded using a standard schema. Incidences of complications were reported as point estimates. Associations between risk factors and complications were characterized in univariate analysis using the two-tailed Fisher exact test and in multivariate analysis using multiple logistic regression with bidirectional elimination based on the Akaike information criterion. In both univariate and multivariate analyses, statistical significance was corrected for multiple comparisons using the Benjamini-Hochberg method.

RESULTS

Complications occurred in 6.5% of procedures, including neurological complications in 1.9% and nonneurological complications in 4.8%. Permanent deficits occurred in only 0.2% of cases. Overall, 0.5% of procedures resulted in major complications, while 6.0% resulted in minor complications. Female sex and a history of hypertension or ischemic stroke were associated with an increased risk of complications, while femoral artery access was associated with a decreased risk of complications.

CONCLUSIONS

Pediatric cerebral angiography was shown to have a low rate of major or permanent complications. Children who were female and those with a history of hypertension or ischemic stroke were shown to be at higher risk of complications, while the use of femoral access carried a lower risk of complications.

Cone-Beam Computed Tomography Fusion Technique for Vascular Assessment of Skull Base Meningiomas

OBJECTIVE

Cone-beam computed tomography (CBCT) images for skull base tumors provide detailed vascular information and localization in regard to surrounding bony structures. We report use of the CBCT fusion technique for skull base meningiomas.

METHODS

Six patients with petroclival or petrotentorial meningiomas supplied by multiple arterial systems were preoperatively evaluated using CBCT fusion imaging. Fusion images were reconstructed from three-dimensional rotational angiography with contrast agent injections from the internal carotid artery (ICA) and external carotid artery in 4 cases, vertebral artery and external carotid artery in 1 case, and ICA and vertebral artery in 1 case.

RESULTS

The feeding pedicles and tumor stains from 2 arterial systems were differentiated by separate colors. The courses and territories of the ICA dural feeders or ICA/vertebral artery pial feeders were easily distinguished from the external carotid artery dural feeders. Anastomoses between thin feeders from different arterial systems could be detected. Mixed stain (stain with both colors) was observed in some tumor compartments, suggesting dual supply from 2 arterial systems and the presence of peritumoral anastomoses. All patients underwent preoperative embolization without complications.

CONCLUSIONS

CBCT fusion images clearly visualized the feeders from each arterial system, the vascular compartments within the tumor, and possible peritumoral anastomoses. This technique provides a substantial contribution to both preoperative embolization and surgical resection of skull base meningiomas.

Efficacy of endovascular intratumoral embolization for meningioma: assessment using dynamic susceptibility contrast-enhanced perfusion-weighted imaging

BACKGROUND

In preoperative embolization for intracranial meningioma, endovascular intratumoral embolization is considered to be more effective for the reduction of tumorous vascularity than proximal feeder occlusion. In this study, we aimed to reveal different efficacies for reducing tumor blood flow in meningiomas by comparing endovascular intratumoral embolization and proximal feeder occlusion using dynamic susceptibility contrast-enhanced perfusion-weighted imaging (DSC-PWI).

METHODS

28 consecutive patients were included. DSC-PWI was performed before and after embolization for intracranial meningiomas. Normalized tumor blood volume (nTBV) of voxels of interest of whole tumors were measured from the DSC-PWI data before and after embolization. ΔnTBV% was compared between the cases that received intratumoral embolization and proximal feeder occlusion.

RESULTS

ΔnTBV% in the intratumoral embolization group (42.4±29.8%) was higher than that of the proximal feeder occlusion group (15.3±14.3%, p=0.0039). We used three types of embolic materials and ΔnTBV% did not differ between treatments with or without the use of each material: 42.8±42.4% vs 28.7±20.1% for microspheres (p=0.12), 36.1±20.6% vs 28.1±41.1% for n-butyl cyanoacrylate (p=0.33), and 32.3±37.3% vs 34.1±19.0% for bare platinum coils (p=0.77).

CONCLUSIONS

The flow reduction effect of intratumoral embolization was superior to that of proximal feeder occlusion in preoperative embolization for intracranial meningioma in an assessment using DSC-PWI.

Clinicopathologic Factors Associated with Tumor Necrosis after Preoperative Embolization of Meningiomas

Objective

Preoperative embolization of meningiomas induces necrosis prior to surgery and facilitates resection. Lack of contrast enhancement on postembolization MRI correlates with pathological findings of necrosis and can be used to assess embolization efficacy. This study aimed to examine clinicopathologic factors associated with tumor necrosis after embolization.

Methods

A total of 119 patients with intracranial meningioma who underwent 145 surgical resections between 2010 and 2019 at our institute were reviewed. Inclusion criteria for the study were preoperative embolization with trisacryl gelatin microspheres (Embosphere) or absorbable gelatine sponge (Gelfoam). Postembolization Gd-enhanced T1-weighted and angiographic imaging, and histopathologic examination results were reviewed to evaluate the effectiveness of embolization.

Results

In all, 66 patients satisfied the inclusion criteria. In total, 36 patients were embolized with Embosphere and 30 patients were embolized with Gelfoam. Patients embolized with Embosphere had a significantly higher necrosis rate (NR) than patients with Gelfoam (21% vs. 7.1%, P <0.01). The 36 Embosphere patients were analyzed regarding clinicopathologic factors associated with NR. Tumors in 12 patients were located in the parasagittal/falx region; these patients had a significantly lower NR compared with tumors in other locations (10.6% vs. 26.2%, P = 0.016). In all, 13 patients had feeders arising from only the middle meningeal artery (MMA), which was associated with a significantly higher NR (29.3% vs. 14.4%, P = 0.015). In total, 11 patients had meningeal feeders arising from internal carotid artery (ICA), which was associated with a significantly lower NR (9.0% vs. 26.3%, P <0.01).

Conclusion

This study showed embolization agent, tumor location, and blood supply were important factors predicting necrosis after preoperative embolization.

Detailed Arterial Anatomy and Its Anastomoses of the Sphenoid Ridge and Olfactory Groove Meningiomas with Special Reference to the Recurrent Branches from the Ophthalmic Artery

BACKGROUND AND PURPOSE

Detailed arterial anatomy of the sphenoid ridge and olfactory groove meningiomas is complicated due to the fine angioarchitecture and anastomoses between each feeder. Herein, we present details of the arterial anatomy and the relationships of feeders in these lesions.

MATERIALS AND METHODS

This study included 20 patients admitted to our department between April 2015 and March 2020. Conditions of subjects consisted of 16 sphenoid ridge meningiomas and 4 olfactory groove meningiomas. We mainly analyzed arterial anatomy using 3D rotational angiography and slab MIP images of these lesions. We also analyzed the anastomoses of each feeder.

RESULTS

We found that 19 (95%), 15 (75%), and 15 (75%) lesions had feeders from the ophthalmic, internal carotid, and external carotid arteries, respectively. As feeders from the ophthalmic artery, recurrent meningeal arteries were involved in 18 lesions (90%). Fifteen lesions (75%) had anastomoses between each feeder.

CONCLUSIONS

Most of the meningiomas in the sphenoid ridge and olfactory groove had feeders from the ophthalmic and internal carotid arteries. There were various anastomoses between each feeder. This is the first report to demonstrate the detailed arterial anatomy and frequency of recurrent branches from the ophthalmic artery and their anastomoses using detailed imaging techniques.

An Overview of Managements in Meningiomas

Meningioma is the most frequent primary tumor of the central nervous system. Important advances have been achieved in the treatment of meningioma in recent decades. Although most meningiomas are benign and have a good prognosis after surgery, clinicians often face challenges when the morphology of the tumor is complicated or the tumor is close to vital brain structures. At present, the longstanding treatment strategies of meningioma are mainly surgery and radiotherapy. The effectiveness of systemic therapy, such as chemotherapy or targeted therapy, has not been confirmed by big data series, and some clinical trials are still in progress. In this review, we summarize current treatment strategies and future research directions for meningiomas.

Case of Clear Cell Ependymoma Successfully Treated with Preoperative Embolization

Objective

Clear cell ependymoma (CCE) is known to be very similar to hemangioblastoma (HB) in regards to neuroimaging and histopathology. We report a rare case of CCE in which successfully underwent preoperative embolization with a prior diagnosis of HB.

Case Presentation

A 58-year-old woman presented with vertigo for several months. MRI showed the right cerebellar tumor mimicking solid HB. DSA revealed the hypervascular tumor supplied by branches of the posterior inferior cerebellar artery (PICA). To reduce intraoperative bleeding, preoperative embolization was performed using n-butyl-2-cyanoacrylate (NBCA). A flow-guided microcatheter was guided to the proper feeders, and diluted NBCA was injected. Sufficient devascularization was achieved. The tumor was totally resected with minimal blood loss the next day. Postoperative pathological diagnosis was CCE.

Conclusion

This is the first report that preoperative embolization was performed to CCE with careful techniques and recent advanced devices. Since CCE has a poorer prognosis, preoperative embolization for safety total resection may be more important.

Onyx embolization of skull base paragangliomas: a single-center experience

BACKGROUND

Skull base paragangliomas are highly vascular tumors that are often embolized before surgical resection; however, the safety and efficacy of preoperative embolization using an ethylene vinyl alcohol copolymer (Onyx; Medtronic, Dublin, Republic of Ireland) in these tumors is unknown. This retrospective cohort study evaluated patient outcomes after preoperative embolization of skull base paragangliomas using Onyx.

METHODS

We retrospectively analyzed data from all patients with skull base paragangliomas who underwent preoperative Onyx embolization at our institution (January 01, 2005-December 31, 2017). Patient, tumor, embolization, and outcomes data were extracted by reviewing inpatient and outpatient clinical and imaging records.

RESULTS

Seven patients were studied (5/7 [71%] female), 6 with glomus jugulares and 1 with a glomus vagale. The median age was 52 years, and the most common presenting symptom was cranial neuropathy (6/7 [86%]). The tumor vascular supply was from the ascending pharyngeal artery in all 7 cases (100%) with additional feeders including the occipital artery in 5 (71%); internal carotid artery in 3 (43%); middle meningeal, vertebral, and internal maxillary artery each in 2 (29%); and posterior auricular artery in 1 (14%). The median postembolization tumor devascularization was 80% (range, 64-95%). The only postembolization complication was a facial palsy in 1 patient.

CONCLUSION

Preoperative embolization with Onyx affords excellent devascularization for the majority of skull base paragangliomas, and it may facilitate resection of these hypervascular lesions. The advantages provided by Onyx with respect to penetration of intratumoral vessels must be weighed against the risk of cranial neuropathy.

Angiography and embolization of meningiomas

The preoperative embolization of meningiomas has been part of the surgical treatment of large meningiomas for over 45 years. During that time there have been huge advances in the field of endovascular surgery with respect to techniques and instrumentation. Angiography and embolization are usually reserved for the largest tumors where there are concerns over potential blood loss with surgical excision. In this chapter, we discuss the technical aspects of angiography and embolization as well as results and complications.

A comparison of the prevalence and risk factors of complications in intracranial tumor embolization between the Japanese Registry of NeuroEndovascular Therapy 2 (JR-NET2) and JR-NET3

BACKGROUND

The Japanese Registry of NeuroEndovascular Therapy 2 (JR-NET2) and 3 (JR-NET3) were nationwide surveys that evaluated clinical outcomes after neuroendovascular therapy in Japan. The aim of this study was to compare the prevalence and risk factors of complications of intracranial tumor embolization between JR-NET2 and JR-NET3.

METHODS

A total of 1018 and 1545 consecutive patients with intracranial tumors treated with embolization were enrolled in JR-NET2 and JR-NET3, respectively. The prevalence of complications in intracranial tumor embolization and related risk factors were compared between JR-NET2 and JR-NET3.

RESULTS

The prevalence of complications in JR-NET3 (3.69%) was significantly higher than that in JR-NET2 (1.48%) (p = 0.002). The multivariate analysis in JR-NET2 showed that embolization for tumors other than meningioma was the only significant risk factor for complication (odds ratio [OR], 3.88; 95% confidence interval [CI], 1.13-12.10; p = 0.032), and that in JR-NET3 revealed that embolization for feeders other than external carotid artery (ECA) (OR, 3.56; 95% CI, 2.03-6.25; p < 0.001) and use of liquid materials (OR, 2.65; 95% CI, 1.50-4.68; p < 0.001) were significant risks for complications. The frequency of embolization for feeders other than ECA in JR-NET3 (15.3%) was significantly higher than that in JR-NET2 (9.2%) (p < 0.001). Also, there was a significant difference in the frequency of use of liquid materials between JR-NET2 (21.2%) and JR-NET3 (41.2%) (p < 0.001).

CONCLUSIONS

Embolization for feeders other than ECA and use of liquid materials could increase the complication rate in intracranial tumor embolization.