Comparison of surgical and endovascular treatments for fusiform intracranial aneurysms: systematic review and individual patient data meta-analysis.

Fusiform intracranial aneurysms (FIA) are associated with significant morbidity and mortality. We carried out a systematic review and meta-analysis of individual participant data with propensity score adjustment to compare the functional and angiographic outcomes between surgical and endovascular approaches to FIA. We conducted a systematic review for articles on the treatment of FIA with individual patient-level detailing. Data from patients treated for FIA in our institution from 2010 to 2018 were also collected. The primary studied outcome was morbidity, and secondary outcomes were angiographic results and retreatment. Propensity score-adjusted mixed-effects logistic regression models evaluated treatment options, stratified by anatomical location. Compiling original and published data, there were 312 cases, of which 79 (25.3%) had open surgery, and 233 (74.5%) were treated with endovascular procedures. There were no differences between treatment groups, for neither cavernous ICA (OR 1.04, 95% CI 0.05-23.6) nor supraclinoid aneurysms (OR 7.82, 95% CI 0.65-94.4). Both size (OR 1.11, 95% CI 1.03-1.19) and initial mRS (OR 2.0, 95% CI 1.2-3.3) were risk factors for morbidity, independent of location. Neither age nor rupture status influenced the odds of posterior morbidity. Unfavorable angiographic outcomes were more common in the endovascular group for supraclinoid and vertebrobasilar aneurysms (χ2, P < 0.01). There were no differences between morbidity of surgical and endovascular treatments for FIA, regardless of aneurysm location. Size and initial mRS were correlated with functional outcomes, whereas age and rupture status were not. Microsurgery seems to yield better long-term angiographic results compared to endovascular procedures.

The current clinical picture of cerebral proliferative angiopathy: systematic review.

BACKGROUND: Cerebral proliferative angiopathy (CPA) is a rare subset of arteriovenous malformations (AVM). It has unique clinical presentation, angiographic characteristics, and pathophysiology which often brings challenges for the treatment. We aimed to define its epidemiology, pathophysiology are unknown, and best management strategies. METHODS: A systematic review was conducted according to the PRISMA guidelines. MEDLINE was searched for articles regarding CPA. Extracted data included epidemiological, clinical, and angiographical characteristics, treatment, and outcomes. Treatment was classified as conservative, radiosurgery, endovascular, decompression, and indirect vascularization. A meta-analytical approach was employed for description of the data as study-size adjusted percentages or weighted means, as appropriate. RESULTS: Thirty-three studies were analyzed, rendering a total 95 cases-half of which came from a single study. Patients were predominantly young (mean 23 years old) and female (60.0%) presenting with headaches (44.9%), seizures (37.1%), or transient ischemic attacks (33.7%). Hemorrhage was present in 18.0%, but rebleeding rates were as high as 67%. The majority of nidus were > 6 cm (52.5%) with hemispheric extension (73.0%). Capillary angioectatic appearance (85.7%), transdural supply (62.5%), and deep venous drainage (73.0%) were also frequent features. Most patients were treated conservatively (54.4%), followed by endovascular (34.2%). Indirect vascularization and radiosurgery were attempted in five and two patients, respectively. Mean follow-up was 110.8 patient-years. Neurological status improved in 50.7%, remained stable in 40.2%, and worsened in 9.0%. CONCLUSIONS: Conservative and endovascular treatments seem adequate interventions, despite limited evidence. Complementary techniques can be used in patients throughout disease history, according to symptom-based, individualized approach. More studies are required for choosing interventions based on reliable long-term results.

The PHASES score: To treat or not to treat? Retrospective evaluation of the risk of rupture of intracranial aneurysms in patients with aneurysmal subarachnoid hemorrhage.

BACKGROUND AND PURPOSE: The PHASES score was formulated to predict the 5-year risk of rupture for intracranial aneurysms. We retrospectively analyzed all patients treated in our institution for aneurysmal SAH and applied the PHASES score to estimate the probable predicted risk of bleeding in this group of patients. METHODS: Between February 2015 and August 2018, all patients with aneurysmal SAH were retrospectively analyzed and the PHASES score was applied. A total of 155 patients were included with a mean age of 53.8years, including 60 males and 95 females. RESULTS: Of our patients 110 (70.9%) had a PHASES score of below or equal to 5, with a hemorrhagic risk of up to 1.3% over 5years. If we analyze the patients with a risk of below 2% this figure increases to 122 patients (78.7%). Of these 99.3% were European and 0.6% were Japanese (1 patient). In 86 patients (55.4%), the aneurysm was smaller than 5mm and in 10 patients (6.4%) the aneurysm was located in the posterior circulation. CONCLUSION: Of our patients 78.7% had less than a 2% 5-year rupture risk based on their PHASES score, highlighting the discrepancy of the rupture risk calculated with the PHASES score when hypothetically applied to this group of patients. In the hypothetical scenario that our patients had unruptured aneurysms, our retrospective analysis shows that the PHASES score may only provide a weak tool for clinicians to use in the decision-making process as to whether or not to treat these aneurysms.

Vessel wall MRI revealing inflammation on brain aneurysm associated to chronic mucocutaneous candidiasis.

Some authors have reported the association between CMC and brain aneurysms. In this paper it is reported a fusiform brain aneurysm associated to CMC and the vessel wall MRI findings.

Post-traumatic carotid-cavernous fistula in a pediatric patient: a case-based literature review.

BACKGROUND: Carotid-cavernous fistula (CCF) is a shunt between the carotid artery and the cavernous sinus. Traumatic CCFs are diagnosed in 0.2% of head traumas being only 4.6% of the pediatric population. Classified by Barrow in 1985, type A CCF is the most frequent, occurring in 75% of cases. Type A is characterized by direct and high-flow CCF that generally can occur as a result of traumatic injury or rupture of an intracavernous aneurysm. CASE PRESENTATION: The subject was an 8-year-old boy with penetrating trauma to his left eye. During the initial evaluation, a computed tomography (CT) scan was unremarkable, and after relief of symptoms, the patient was discharged. Seven days later, he developed grade I proptosis, conjunctival chemosis, ophthalmoplegia (III, IV, and VI cranial nerve palsies), and left-sided ptosis and mydriasis. Arteriography confirmed a post-traumatic CCF, and the patient was treated with an endovascular detachable balloon. CONCLUSION: CCF should be suspected in craniofacial traumas with ocular symptoms. The presence of a skull base fracture on CT is a poor predictor of CCF associated with head trauma. Early diagnosis and treatment can prevent permanent neurological deficits and unfavorable outcomes.

Traumatic carotid-cavernous fistula at the anterior ascending segment of the internal carotid artery in a pediatric patient.

INTRODUCTION: Traumatic carotid-cavernous fistula (CCF) in children is a rare condition. Early diagnosis and treatment is still a challenge, and it is associated with good neurological recovery. CASE SUMMARY: We present a rare case of a 10-year-old boy with mild head trauma, who developed a CCF at the anterior segment of the ascending internal carotid artery. The patient was treated with endovascular coil embolization and evolved with a favorable outcome. DISCUSSION: Most of reports in the literature address the traumatic CCF in adult patients, in which early treatment may prevent poor recovery or fatal outcomes. The diagnosis and management of this condition are discussed based on a literature review. CONCLUSION: It is important to keep a high degree of suspicion for CCF, especially in traumatic head injury associated with skull base fracture, since the early diagnosis and treatment may prevent potentially permanent neurological deficits.

Acute and chronic changes in porcine rete mirabile after embolization with the Menox system: angiographic and histopathological analyses.

Objective: To evaluate acute and chronic changes seen on angiographic and histopathological studies of porcine rete mirabile, comparing those treated with the Menox liquid embolic system (LES) and those treated with the Onyx LES. Materials and Methods: Five pigs, each weighing approximately 35 kg, were submitted to rete mirabile embolization under general anesthesia and fluoroscopic guidance, with the Menox LES or Onyx LES. Four animals were treated with the Menox LES and underwent cerebral angiography, followed by euthanasia, at 1, 30, 60, and 90 days after embolization. One animal was treated with the Onyx LES underwent the same procedures at 30 days after embolization. In a subsequent histopathological analysis, we compared the Menox LES and Onyx LES in terms of the acute and chronic changes observed. Results: We observed no significant changes in blood pressure, heart rate, or electrocardiographic parameters that could be attributed to the super-selective infusion of dimethyl sulfoxide or the Menox embolic agent. Fluoroscopy showed adequate material opacity, appropriate progression to the center of the rete mirabile and complete unilateral embolization. Microcatheters were uneventfully detached from the embolized nidus. We observed mild to moderate intravascular and extravascular inflammatory responses, without histological evidence of necrotizing arteritis. There were no adverse neurovascular events. Conclusion: The Menox LES appears to be safe and effective, as well as being apparently equivalent to the Onyx LES in terms of the postprocedure angiographic and histopathological findings.

Objetivo: Avaliar as alterações angiográficas e histopatológicas agudas e crônicas em rete mirabile suína tratadas com o Menox liquid embolic system (LES) e comparar essas alterações com a embolização com Onyx LES. Materiais e Métodos: A embolização da rete mirabile com Menox LES e Onyx LES foi realizada em cinco suínos pesando cerca de 35 kg sob anestesia geral e orientação fluoroscópica. Quatro animais tratados com Menox LES foram submetidos a angiografia cerebral seguida de eutanásia após 1, 30, 60 e 90 dias e um animal tratado com Onix LES foi submetido ao mesmo procedimento após 30 dias. A análise histopatológica subsequente para alterações agudas e crônicas avaliou o desempenho do Menox LES comparado ao Onyx LES. Resultados: Não foram observadas alterações significativas atribuíveis à infusão superseletiva de dimetilsulfóxido ou Menox nos parâmetros de pressão arterial, frequência cardíaca ou eletrocardiograma. A fluoroscopia mostrou opacidade adequada do material, progressão adequada para o centro da rete mirabile e embolização unilateral completa. Os microcateteres foram retirados do nidus embolizado sem complicações. Observou-se resposta inflamatória intravascular e extravascular leve a moderada, sem indício histológico de arterite necrosante. Nenhum dos casos apresentou eventos neurovasculares adversos. Conclusão: A injeção de Menox LES mostrou-se segura e eficaz, além de ser equivalente ao Onyx LES em relação aos achados angiográficos e histopatológicos pós-procedimento.

Microvascular lung vessels obstructive thromboinflammatory syndrome in patients with COVID-19: Insights from lung intravascular optical coherence tomography.

Background: Microvascular lung vessels obstructive thromboinflammatory syndrome has been proposed as a possible mechanism of respiratory failure in COVID-19 patients. However, it has only been observed in post-mortem studies and has never been documented in vivo, probably because of a lack of CT scan sensitivity in small pulmonary arteries. The aim of the present study was to assess the safety, tolerability, and diagnostic value of optical coherence tomography (OCT) for the assessment of patients with COVID-19 pneumonia for pulmonary microvascular thromboinflammatory syndrome. Methods: The COVID-OCT trial was a multicenter, open-label, prospective, interventional clinical study. Two cohorts of patients were included in the study and underwent pulmonary OCT evaluation. Cohort A consisted of patients with COVID-19 with a negative CT scan for pulmonary thrombosis and elevated thromboinflammatory markers (D-dimer > 10,000 ng/mL or 5,000 < D-dimer < 10,000 ng/mL and one of: C-reactive Protein > 100 mg/dL, IL-6 > 6 pg/mL, or ferritin > 900 ng/L). Cohort B consisted of patients with COVID-19 and a CT scan positive for pulmonary thrombosis. The primary endpoints of the study were: (i) to evaluate the overall safety of OCT investigation in patients with COVID-19 pneumonia, and (ii) to report on the potential value of OCT as a novel diagnostic tool for the diagnosis of microvascular pulmonary thrombosis in COVID-19 patients. Results: A total of 13 patients were enrolled. The mean number of OCT runs performed in each patient was 6.1 ± 2.0, both in ground glass and healthy lung areas, achieving a good evaluation of the distal pulmonary arteries. Overall, OCT runs identified microvascular thrombosis in 8 patients (61.5%): 5 cases of red thrombus, 1 case of white thrombus, and 2 cases of mixed thrombus. In Cohort A, the minimal lumen area was 3.5 ± 4.6 mm2, with stenosis of 60.9 ± 35.9% of the area, and the mean length of thrombus-containing lesions was 5.4 ± 3.0 mm. In Cohort B, the percentage area obstruction was 92.6 ± 2.6, and the mean thrombus-containing lesion length was 14.1 ± 13.9 mm. No peri-procedural complications occurred in any of the 13 patients. Conclusion: OCT appears to be a safe and accurate method of evaluating the distal pulmonary arteries in hospitalized COVID-19 patients. Here, it enabled the first in vivo documentation of distal pulmonary arterial thrombosis in patients with elevated thromboinflammatory markers, even when their CT angiogram was negative for pulmonary thrombosis. Clinical trial registration: ClinicalTrial.gov, identifier NCT04410549.

Perimedullary arteriovenous fistulas in children: report on six cases.

BACKGROUND: Perimedullary arteriovenous fistulas (PMAVFs) are rare spinal lesions and even more uncommon in children. OBJECTIVE: The aim of this study was to document rare occurrences of this type of arteriovenous malformation in six children treated at our institution. METHODS: The clinical data, radiological findings, and treatment in six cases of PMAVFs were reviewed. Six patients with PMAVFs were managed at our institution over a 5-year period. The patients (four girls and two boys), ranging in age from 6 to 15 years, presented with initially fluctuating, and eventually permanent and progressive, sudden-onset paraparesis, sensory disturbances, and sphincter dysfunction. The duration of symptoms before diagnosis ranged from 1 week to 13 years. RESULTS: All the patients underwent magnetic resonance imaging and spinal selective angiography, which demonstrated the characteristic imaging of an arteriovenous fistula. Embolization of the arteriovenous fistula was initially attempted in three patients with successful occlusion of the fistula in two. For the remaining cases, open surgery was performed, with complete occlusion of the fistula. There was no morbidity, regardless of the treatment performed. All the patients experienced neurological improvement after treatment. CONCLUSIONS: No specific clinical or radiological characteristic of PMAVFs in the pediatric population was observed when our series was compared with a general series. Early diagnosis and timing of the therapeutic intervention seemed to avoid the development of irreversible ischemic myeloradiculopathy and prevented hemorrhage. Treatment for PMAVFs is difficult to standardize because these are extremely rare lesions with different angioarchitecture configurations.

Development of a new experimental model of saccular aneurysm by intra-arterial incubation of papain in rabbits.

INTRODUCTION: Experimental saccular aneurysms can be created with surgical techniques of the arterial wall or by injecting pancreatic elastase. Papain is an enzyme with properties similar to those of elastase, and it has not been tested for this purpose. The objective of this study was to determine whether papain produces saccular aneurysms. METHODS: Eleven New Zealand white rabbits (1.9-3.0 kg) were divided into two groups: group I (n = 8)-papain, and group II (n = 3)-sham. The animals underwent surgical exposure of the neck; the right common carotid artery was used as the test and the left common carotid artery as the control. On the 21st day after surgery, animals were sacrificed for removal of the arteries, measurements, and histological analysis. We determine formation of aneurysm to occur when the test artery dilated compared to the control. RESULTS: There was no aneurysm formation in the sham group. The papain group showed aneurysm formation in all cases (100%). The average diameter of the aneurysms was 3.8 ± 1.4 mm and the average length was 16.7 ± 6.0 mm. The histological analysis showed a destruction of the elastic fibers in 100% of cases, mild inflammation in 62.5%, intimal fibrosis in 50%, endothelial injury in 100%, and thrombosis in 100% of cases. CONCLUSION: Papain was capable of forming aneurysms with histological characteristics similar to those of elastase-induced aneurysms; however, a comparative study is necessary to determine whether the papain is superior to elastase in the production of experimental saccular aneurysms.

Follow-up of endovascular treatment of direct carotid-cavernous fistulas.

INTRODUCTION: Direct carotid-cavernous fistula (CCF) is a direct communication between the internal carotid artery (ICA) and the cavernous sinus. Some patients treated with detachable balloons develop pseudoaneurysms or present with a true aneurysm recanalization in the cavernous ICA with poorly known long-term radiological and clinical progression. The objective of the present study was to evaluate the long-term clinical and radiological progression of patients treated with detachable balloons. METHODS: The present study evaluated 13 patients previously treated for direct CCF by an endovascular approach. RESULTS: The follow-up period ranged between 19 and 128 months. Ophthalmological evaluation demonstrated alterations in eight patients (61.5%). All of these alterations were already present from the moment of the treatment and displayed no signs of progression. Cranial magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) were performed in all patients, and 11 pseudoaneurysms were demonstrated in ten of the 11 patients in whom ICA patency had been preserved. Five patients were submitted for cerebral digital subtraction angiography (DSA) to characterize the pseudoaneurysms previously observed on MRA studies, with no significant differences in morphology, size, aneurismal neck, and number of lesions. CONCLUSION: Endovascular treatment of direct CCF with detachable balloons has been shown to be a long-term effective and stable therapeutic method. The authors found asymptomatic pseudoaneurysms in 91% of cases where the ICA patency was preserved. MRI and MRA demonstrated an accuracy similar to that of DSA in the diagnosis of pseudoaneurysms of cavernous ICA.

Ethanol sclerotherapy of superficial venous malformation: a new procedure.

BACKGROUND: Superficial venous malformations (SVM) are the most frequent vascular malformations. Outpatient percutaneous treatment with ethanol injection has rarely been described. OBJECTIVE: To analyze the results from treating SVM patients with ethanol sclerotherapy. METHODS: 81 patients were followed up prospectively over a median period of 18 months. 47 were female and 34 were male with a median age of 21 years. Most of the lesions were located in the limbs and the main symptom reported was pain. Each patient underwent fortnightly alcohol injection sessions. RESULTS: The lesions and the symptoms completely disappeared or improved in 77 patients. There were no complications in 64 patients, while 11 presented a small skin ulcer, 3 hyperpigmentation and 3 paresthesia. CONCLUSION: Ethanol sclerotherapy for SVM patients was effective, with a low complication rate.

Spinal arteriovenous malformation without endovascular arterial access: is a combined neurosurgical approach and direct venous puncture an option?

This case report describes a combined neurosurgical and endovascular approach for the treatment of a conus medullaris arteriovenous malformation resulting in considerable improvement in the patient's neurological condition (modified Rankin Scale score 2).

Republished: Spinal arteriovenous malformation without endovascular arterial access: is a combined neurosurgical approach and direct venous puncture an option?

This case report describes a combined neurosurgical and endovascular approach for the treatment of a conus medullaris arteriovenous malformation resulting in considerable improvement in the patient's neurological condition (modified Rankin Scale score 2).

Management of acute stroke and urgent neurointerventional procedures during COVID-19 pandemic: recommendations on the Scientific Department on Cerebrovascular Diseases of the Brazilian Academy of Neurology, Brazilian Society of Cerebrovascular Diseases and Brazilian Society of Neuroradiology.

INTRODUCTION: Although the 2019 severe acute respiratory syndrome coronavirus 2 infection (SARS-CoV-2, COVID-19) pandemic poses new challenges to the healthcare system to provide support for thousands of patients, there is special concern about common medical emergencies, such as stroke, that will continue to occur and will require adequate treatment. The allocation of both material and human resources to fight the pandemic cannot overshadow the care for acute stroke, a time-sensitive emergency that with an inefficient treatment will further increase mortality and long-term disability. OBJECTIVE: This paper summarizes the recommendations from the Scientific Department on Cerebrovascular Diseases of the Brazilian Academy of Neurology, the Brazilian Society of Cerebrovascular Diseases and the Brazilian Society of Neuroradiology for management of acute stroke and urgent neuro-interventional procedures during the COVID-19 pandemic, including proper use of screening tools, personal protective equipment (for patients and health professionals), and patient allocation.

Percutaneous vertebroplasty for multiple myeloma of the cervical spine.

INTRODUCTION: Spinal involvement is a common presentation of multiple myeloma (MM); however, the cervical spine is the least common site of myelomatous involvement. Few studies evaluate the results of percutaneous vertebroplasty (PV) in the treatment of MM of the spine. The purpose of this series is to report on the use of PV in the treatment of MM of the cervical spine and to review the literature. MATERIALS AND METHODS: From January 1994 to October 2007, four patients (three men and one woman; mean age, 45 years) who underwent five PV for painful MM in the cervical spine were retrospectively reviewed. The pain was estimated by the patient on a verbal analogic scale. Clinical follow-up was available for all patients (mean, 27.5 months; range, 1-96 months). RESULTS: The mean volume of cement injected per vertebral body was 2.3 +/- 0.8 mL (range, 1.0-4.0 mL) with a mean vertebral filling of 55.0 +/- 12.0% (range, 40.0-75.0%). Analgesic efficacy was achieved in all patients. One patient had a spinal instability due to a progression of spinal deformity noted on follow-up radiographs, without clinical symptoms. Cement leakage was detected in three (60%) of the five treated vertebrae. There was no clinical complication. CONCLUSIONS: The present series suggests that PV for MM of the cervical spine is safe and effective for pain control; nonetheless, the detrimental impact of the disease on bone quality should prompt close radiological follow-up after PV owing to the risk of spinal instability.

Epidemiological analysis of 1404 patients with intracranial aneurysm followed in a single Brazilian institution.

BACKGROUND: We sought to evaluate the epidemiology of intracranial aneurysms in relation to location, gender, age, presence of multiple aneurysms, and comorbidities in the Brazilian population. METHODS: We performed a prospective analysis of a cohort of 1404 patients diagnosed with intracranial aneurysm admitted to the Hospital das Clinicas of the University of Sao Paulo, a referral hospital for the treatment of cerebrovascular diseases in Brazil. Patients admitted between September 2009 and September 2018 with radiological diagnosis of intracranial aneurysm were included in the study. RESULTS: A total of 2251 aneurysms were diagnosed. Females accounted for 1090 aneurysms (77.6%) and the mean age at diagnosis was 54.9 years (ranging 15-88). The most common location was middle cerebral artery (MCA) with 593 aneurysms (26.3%) followed by anterior cerebral artery (ACA) with 417 aneurysms (18.5%) and internal carotid artery in the posterior communicating segment with 405 aneurysms (18.0%). Males had higher rates of ACA aneurysms (29.7%) while females had higher rates of MCA aneurysms (26.1%). Sorting by size, 492 aneurysms were <5 mm (21.8%), 1524 measured 5-10 mm (67.7%), 119 size 11-24 mm (5.3%), and 116 were >24 mm (5.2%). The occurrence of multiple aneurysms was associated with female gender (P < 0.001) and smoking (P < 0.001), but not with hypertension (P = 0.121). CONCLUSION: In this population, the occurrence of intracranial aneurysm is related to several factors, including gender, age, smoking, and hypertension. Our study brought to light important characteristics of a large number of Brazilian patients regarding epidemiology, location, size, and multiplicity of intracranial aneurysms.

Endovascular management of acute epidural hematomas: clinical experience with 80 cases.

OBJECTIVE Small acute epidural hematomas (EDHs) treated conservatively carry a nonmeasurable risk of late enlargement due to middle meningeal artery (MMA) lesions. Patients with EDHs need to stay hospitalized for several days, with neurological supervision and repeated CT scans. In this study, the authors analyzed the safety and efficacy of the embolization of the involved MMA and associated lesions. METHODS The study group consisted of 80 consecutive patients harboring small- to medium-sized EDHs treated by MMA embolization between January 2010 and December 2014. A literature review cohort was used as a control group. RESULTS The causes of head injury were falls, traffic-related accidents (including car, motorcycle, and pedestrian vs vehicle accidents), and assaults. The EDH topography was mainly temporal (lateral or pole). Active contrast leaking from the MMA was seen in 57.5%; arteriovenous fistulas between the MMA and diploic veins were seen in 10%; and MMA pseudoaneurysms were found in 13.6% of the cases. Embolizations were performed under local anesthesia in 80% of the cases, with N-butyl-2-cyanoacrylate, polyvinyl alcohol particles, or gelatin sponge (or a combination of these), obtaining MMA occlusion and complete resolution of the vascular lesions. All patients underwent follow-up CT scans between 1 and 7 days after the embolization. In the 80 cases in this series, no increase in size of the EDH was observed and the clinical evolution was uneventful, without Glasgow Coma Scale score modification after embolization and with no need for surgical evacuation. In contrast, the control cohort from the literature consisted of 471 patients, 82 (17.4%) of whom shifted from conservative treatment to surgical evacuation. CONCLUSIONS This study suggests that MMA embolization is a highly effective and safe method to achieve size stabilization in nonsurgically treated acute EDHs.

Acute and chronic changes in porcine rete mirabile after embolization with the Menox system: angiographic and histopathological analyses / Alterações angiográficas e histopatológicas agudas e crônicas da rete mirabile no modelo suíno com sistema embólico líquido Menox

Abstract Objective: To evaluate acute and chronic changes seen on angiographic and histopathological studies of porcine rete mirabile, comparing those treated with the Menox liquid embolic system (LES) and those treated with the Onyx LES. Materials and Methods: Five pigs, each weighing approximately 35 kg, were submitted to rete mirabile embolization under general anesthesia and fluoroscopic guidance, with the Menox LES or Onyx LES. Four animals were treated with the Menox LES and underwent cerebral angiography, followed by euthanasia, at 1, 30, 60, and 90 days after embolization. One animal was treated with the Onyx LES underwent the same procedures at 30 days after embolization. In a subsequent histopathological analysis, we compared the Menox LES and Onyx LES in terms of the acute and chronic changes observed. Results: We observed no significant changes in blood pressure, heart rate, or electrocardiographic parameters that could be attributed to the super-selective infusion of dimethyl sulfoxide or the Menox embolic agent. Fluoroscopy showed adequate material opacity, appropriate progression to the center of the rete mirabile and complete unilateral embolization. Microcatheters were uneventfully detached from the embolized nidus. We observed mild to moderate intravascular and extravascular inflammatory responses, without histological evidence of necrotizing arteritis. There were no adverse neurovascular events. Conclusion: The Menox LES appears to be safe and effective, as well as being apparently equivalent to the Onyx LES in terms of the postprocedure angiographic and histopathological findings.

Resumo Objetivo: Avaliar as alterações angiográficas e histopatológicas agudas e crônicas em rete mirabile suína tratadas com o Menox liquid embolic system (LES) e comparar essas alterações com a embolização com Onyx LES. Materiais e Métodos: A embolização da rete mirabile com Menox LES e Onyx LES foi realizada em cinco suínos pesando cerca de 35 kg sob anestesia geral e orientação fluoroscópica. Quatro animais tratados com Menox LES foram submetidos a angiografia cerebral seguida de eutanásia após 1, 30, 60 e 90 dias e um animal tratado com Onix LES foi submetido ao mesmo procedimento após 30 dias. A análise histopatológica subsequente para alterações agudas e crônicas avaliou o desempenho do Menox LES comparado ao Onyx LES. Resultados: Não foram observadas alterações significativas atribuíveis à infusão superseletiva de dimetilsulfóxido ou Menox nos parâmetros de pressão arterial, frequência cardíaca ou eletrocardiograma. A fluoroscopia mostrou opacidade adequada do material, progressão adequada para o centro da rete mirabile e embolização unilateral completa. Os microcateteres foram retirados do nidus embolizado sem complicações. Observou-se resposta inflamatória intravascular e extravascular leve a moderada, sem indício histológico de arterite necrosante. Nenhum dos casos apresentou eventos neurovasculares adversos. Conclusão: A injeção de Menox LES mostrou-se segura e eficaz, além de ser equivalente ao Onyx LES em relação aos achados angiográficos e histopatológicos pós-procedimento.