Daniel D Cavalcanti | Instituto Estadual do Cérebro Paulo Niemeyer (IECPN) (original) (raw)

Papers by Daniel D Cavalcanti

Research paper thumbnail of Surgical Anatomy of the Brainstem

Research paper thumbnail of A propensity-adjusted comparison of middle meningeal artery embolization versus conventional therapy for chronic subdural hematomas

Journal of Neurosurgery, 2021

OBJECTIVEMiddle meningeal artery (MMA) embolization is a promising treatment strategy for chronic... more OBJECTIVEMiddle meningeal artery (MMA) embolization is a promising treatment strategy for chronic subdural hematomas (cSDHs). However, studies comparing MMA embolization and conventional therapy (surgical intervention and conservative management) are limited. The authors aimed to compare MMA embolization versus conventional therapy for cSDHs using a propensity-adjusted analysis.METHODSA retrospective study of all patients with cSDH who presented to a large tertiary center over a 2-year period was performed. MMA embolization was compared with surgical intervention and conservative management. Neurological outcome was assessed using the modified Rankin Scale (mRS). A propensity-adjusted analysis compared MMA embolization versus surgery and conservative management for all individual cSDHs. Primary outcomes included change in hematoma diameter, treatment failure, and complete resolution at last follow-up.RESULTSA total of 231 patients with cSDH met the inclusion criteria. Of these, 35 (...

Research paper thumbnail of Surgery of the Brainstem

Surgery of the Brainstem, 2020

Research paper thumbnail of Avoiding the Radial Paradox: Neuroendovascular Femoral Access Outcomes After Radial Access Adoption

Neurosurgery, 2021

BACKGROUND Transradial access (TRA) for neuroendovascular procedures is increasing in prevalence.... more BACKGROUND Transradial access (TRA) for neuroendovascular procedures is increasing in prevalence. The safety benefits of TRA at a patient level may be offset at a population level by a paradoxical increase in transfemoral access (TFA) vascular access site complications (VASCs), the so-called "radial paradox." OBJECTIVE To study the effect of TRA adoption on TFA performance and outcomes in neuroendovascular procedures. METHODS Data were collected for all procedures performed over a 10-mo period after radial adoption at a single center. RESULTS Over the study period, 1084 procedures were performed, including 719 (66.3%) with an intent to treat by TRA and 365 (33.7%) with an intent to treat by TFA. Thirty-two cases (4.4%) crossed over from TRA to TFA, and 2 cases (0.5%) crossed over from TFA to TRA. TFA was performed in older patients (mean [standard deviation] TFA, 63 [15] vs TRA, 56 [16] years) using larger sheath sizes (≥7 French; TFA, 56.2% vs TRA, 2.3%) (P < .001 for both comparisons). Overall, 29 VASCs occurred (2.7%), including 27 minor (TFA, 4.6% [18/395] vs TRA, 1.3% [9/689], P = .002) and 2 major (TFA, 0.3% [1/395] vs TRA, 0.1% [1/689], P > .99) complications. Independent predictors of VASC included TFA (OR 2.8, 95% confidence interval [CI] 1.1-7.4) and use of dual antiplatelet therapy (OR 4.2, 95% CI 1.6-11.1). CONCLUSION TFA remains an important access route, despite a predominantly radial paradigm, and is disproportionately used in patients at increased risk for VASCs. TFA proficiency may still be achieved in predominantly radial practices without an increase in femoral complications.

Research paper thumbnail of Percutaneous transorbital direct puncture to obliterate a cavernous sinus dural arteriovenous fistula

Journal of NeuroInterventional Surgery, 2021

Cavernous sinus dural arteriovenous fistulas (CS-DAVF) can have an indolent course, with insidiou... more Cavernous sinus dural arteriovenous fistulas (CS-DAVF) can have an indolent course, with insidious onset, but still showing a high likelihood of spontaneous resolution.1 Nevertheless, symptoms in a subset of patients evolve more rapidly, with malignant signs on imaging, warranting intervention.2 We report on a patient in his 40s presenting with redness and proptosis of the right eye, intermittent blurred vision and diplopia. Once ophthalmological examination revealed increased intraocular pressure and imaging showed cortical venous congestion, the decision was made to obliterate a CS-DAVF involving the posteromedial right cavernous sinus.Multiple arteries including branches of the ascending pharyngeal artery, occipital artery and bilateral meningohypophyseal trunks supplied the fistula. Once transarterial embolization was deemed unsafe and both inferior petrosal sinuses did not grant access to the right cavernous sinus, a direct puncture to the cavernous sinus was performed to succe...

Research paper thumbnail of Safety and Feasibility of Out-of-Bed Mobilization for Patients With External Ventricular Drains in a Neurosurgical Intensive Care Unit

Journal of Acute Care Physical Therapy, 2018

Introduction: Prolonged bed rest is a frequent problem for patients with critical illness that ma... more Introduction: Prolonged bed rest is a frequent problem for patients with critical illness that may negatively impact survival, quality of life, and medical care cost. Patients with critical neurologic problems are often kept on bed rest or only cleared to perform bed-based activities because of the inherent risk of displacing or damaging intracranial monitoring devices such as the external ventricular drains (EVDs) during activity. Specific recommendations for out-of-bed (OOB) mobilization of such patients are lacking. Purpose: To review the occurrence of adverse events related to OOB mobilization in patients with EVDs. Methods: This was a retrospective study. Data from all adult patients with an EVD and medical clearance for OOB physical therapy (PT) from October 2014 to November 2016 were analyzed. Results: Eighteen patients with EVDs received 108 interventions of OOB PT sessions during this period. No catheter-related mechanical complications occurred during or immediately following the sessions. No serious adverse events were recorded. Minor adverse events included transient dizziness, headache, episodes of hypertension, and hypotension. Vital signs showed no clinically relevant variations before and after the sessions. Conclusions: OOB mobilization was feasible and safe in this group of patients. The effect on morbidity and survival should be further investigated in a larger prospective study.

Research paper thumbnail of Foramen Magnum Meningiomas: Surgical Management of 25 Cases

Journal of Neurological Surgery Part B: Skull Base, 2012

Research paper thumbnail of Molecular genetics of familial cerebral cavernous malformations

Neurosurgical Focus, 2006

✓Cerebral cavernous malformations (CMs) are angiographically occult neurovascular lesions that co... more ✓Cerebral cavernous malformations (CMs) are angiographically occult neurovascular lesions that consist of enlarged vascular channels without intervening normal parenchyma. Cavernous malformations can occur as sporadic or auto-somal-dominant inherited conditions. Approximately 50% of Hispanic patients with cerebral CMs have the familial form, compared with 10 to 20% of Caucasian patients. There is no difference in the pathological findings or presentation in the sporadic and familial forms. To date, familial CMs have been attributed to mutations at three different loci: CCM1 on 7q21.2, CCM2 on 7p15-p13, or CCM3 on 3q25.2-q27. The authors summarize the current understanding of the molecular events underlying familial CMs.

Research paper thumbnail of Endovascular Aneurysm Treatment

Introduction to Vascular Neurosurgery, 2022

Research paper thumbnail of Stent-Assisted Coiling of a Sidewall Aneurysm of the Distal Middle Cerebral Artery: 2-Dimensional Operative Video

Operative Neurosurgery, 2020

Sidewall aneurysm treatment often requires complex management strategies. These can include advan... more Sidewall aneurysm treatment often requires complex management strategies. These can include advanced clipping techniques or stent-assisted coiling techniques. Endovascular coiling alone has been associated with high recurrence rates and is often not feasible.1-4 Flow-diversion embolization has recently become a standard of care for many aneurysms, demonstrating high occlusion rates.4,5 However, the third generation of coil-assist stents can be delivered with 0.0165” microcatheters, being an ideal adjunct to manage this group of aneurysms in more distal locations. In this video, a 16-yr-old teenager with Parry-Romberg syndrome and congenital adrenal hyperplasia had an incidental finding of a 6.5-mm sidewall aneurysm arising off the angular branch of the left middle cerebral artery, found during the work-up of complex partial seizures. The patient consented to the procedure. Due to his young age and aneurysm size, a decision was made to treat the aneurysm through an endovascular appro...

Research paper thumbnail of Controversies in Neurosurgery II

A world-class team of neurosurgeons tackles a broad spectrum of current neurosurgical issues in t... more A world-class team of neurosurgeons tackles a broad spectrum of current neurosurgical issues in this unique book, where readers get practical advice and frank commentary on the pros and cons of numerous techniques and methods of approach. With more than 100 internationally renowned contributors, it demonstrates the diversity of approaches to any one clinical problem, reflecting real-life situations where several treatment alternatives may be acceptable.

Research paper thumbnail of Schwanoma Vestibular de Crescimento Rápido

JBNC - JORNAL BRASILEIRO DE NEUROCIRURGIA, 2018

A história natural dos schwanomas vestibulares ainda não é totalmente conhecida, mas a maioria de... more A história natural dos schwanomas vestibulares ainda não é totalmente conhecida, mas a maioria destas lesões tende ao crescimento lento, algumas vezes sem qualquer manifestação clínica durante toda a vida do indivíduo, sendo em ocasiões achado de autópsias. Consideráveis avanços no conhecimento da anatomia da base do crânio, assim como os recursos tecnológicos de eletrofisiologia, como a monitorização intra-operatória têm possibilitado índices crescentes de preservação funcional do nervo facial e da audição. Devido a isso, a ressecção cirúrgica completa da lesão permanece sendo o tratamento de escolha quando possível. No entanto, em casos selecionados, o tratamento conservador é uma opção muito bem aceita, desde que haja um seguimento radiológico estrito. Opções terapêuticas como a radiocirurgia são também válidas e devem sempre ser consideradas no armamentarium neurocirúrgico. Novos estudos com quimioterápicos (bevacizumab) também podem mudar a conduta referente às indicações cirúr...

Research paper thumbnail of Surgical approaches for the lateral mesencephalic sulcus

Journal of Neurosurgery, 2019

OBJECTIVEThe brainstem is a compact, delicate structure. The surgeon must have good anatomical kn... more OBJECTIVEThe brainstem is a compact, delicate structure. The surgeon must have good anatomical knowledge of the safe entry points to safely resect intrinsic lesions. Lesions located at the lateral midbrain surface are better approached through the lateral mesencephalic sulcus (LMS). The goal of this study was to compare the surgical exposure to the LMS provided by the subtemporal (ST) approach and the paramedian and extreme-lateral variants of the supracerebellar infratentorial (SCIT) approach.METHODSThese 3 approaches were used in 10 cadaveric heads. The authors performed measurements of predetermined points by using a neuronavigation system. Areas of microsurgical exposure and angles of the approaches were determined. Statistical analysis was performed to identify significant differences in the respective exposures.RESULTSThe surgical exposure was similar for the different approaches—369.8 ± 70.1 mm2 for the ST; 341.2 ± 71.2 mm2 for the SCIT paramedian variant; and 312.0 ± 79.3 mm...

Research paper thumbnail of Accessing the Anterior Mesencephalic Zone: Orbitozygomatic Versus Subtemporal Approach

World neurosurgery, Jan 7, 2018

Despite the latest developments in microsurgery, electrophysiological monitoring, and neuroimagin... more Despite the latest developments in microsurgery, electrophysiological monitoring, and neuroimaging, the surgical management of intrinsic brainstem lesions remains challenging. Several safe entry points have been described to access the different surfaces of the brainstem. Knowledge of this entry zone anatomy is critical to performing a safe and less morbid approach. To access the anterior midbrain surface, a well-known entry point is the anterior mesencephalic (AM) zone. Our aim was to quantify surgical AM zone exposure through the orbitozygomatic (OZ) and subtemporal (ST) approaches. We also analyzed the angular exposure along the horizontal and vertical axis angles for the AM zone. Ten cadaveric heads were dissected using the OZ and ST approaches for anterior midbrain surface exposure. A neuronavigation system was used to determine the 3-dimensional coordinates. The area of surgical exposure, angular exposure, and anatomical limits of each craniotomy were evaluated and determined ...

Research paper thumbnail of Potential application of a handheld confocal endomicroscope imaging system using a variety of fluorophores in experimental gliomas and normal brain

Neurosurgical Focus, 2014

Object The authors sought to assess the feasibility of a handheld visible-wavelength confocal end... more Object The authors sought to assess the feasibility of a handheld visible-wavelength confocal endomicroscope imaging system (Optiscan 5.1, Optiscan Pty., Ltd.) using a variety of rapid-acting fluorophores to provide histological information on gliomas, tumor margins, and normal brain in animal models. Methods Mice (n = 25) implanted with GL261 cells were used to image fluorescein sodium (FNa), 5-aminolevulinic acid (5-ALA), acridine orange (AO), acriflavine (AF), and cresyl violet (CV). A U251 glioma xenograft model in rats (n = 5) was used to image sulforhodamine 101 (SR101). A swine (n = 3) model with AO was used to identify confocal features of normal brain. Images of normal brain, obvious tumor, and peritumoral zones were collected using the handheld confocal endomicroscope. Histological samples were acquired through biopsies from matched imaging areas. Samples were visualized with a benchtop confocal microscope. Histopathological features in corresponding confocal images and ph...

Research paper thumbnail of Aplasia of the Anterior Arch of Atlas Associated With Multiple Congenital Disorders

Neurosurgery, 2011

BACKGROUND AND IMPORTANCE Congenital clefts and aplasias of the atlas vertebra are rare. A nonfus... more BACKGROUND AND IMPORTANCE Congenital clefts and aplasias of the atlas vertebra are rare. A nonfused posterior arch occurs in 4% of the population; in contrast, a nonfused anterior arch occurs in only 0.1%. To the best of our knowledge, this is the first description of the combination of anterior arch aplasia and a cleft of the posterior arch of the atlas associated with Klippel-Feil and Treacher-Collins syndromes and Sprengel deformity. CLINICAL PRESENTATION An 11-year-old girl presented with neck pain and symptoms of myelopathy, including upper- and lower-extremity paresthesia. Computed tomography revealed significant congenital bony anomalies of the cervical spine, with congenital fusion of C2 through C5. There was aplasia of the anterior ring of C1 (A 2.3-cm gap was present within the anterior aspect of the lateral masses). The posterior elements of C3 and C4 were fused, and signs of Sprengel deformity were present. Magnetic resonance imaging revealed effacement of the ventral ce...

Research paper thumbnail of The pretemporal approach to anterolateral midbrain cavernous malformations

Neurosurgical Focus: Video, 2019

Operating on the anterolateral midbrain is challenging due to limited surgical freedom provided b... more Operating on the anterolateral midbrain is challenging due to limited surgical freedom provided by classic approaches and restraints imposed by the basilar artery apex and branches, their perforators, and the oculomotor nerve (Abla et al., 2011; Bricolo and Turazzi, 1995; Cavalcanti et al., 2016).This video demonstrates the benefits provided by the pretemporal approach for resection of an anterolateral mesencephalic cavernous malformation (Chaddad-Neto et al., 2014; de Oliveira et al., 1995). Four steps are well demonstrated in the video: 1) section of temporal pole veins to the sphenoparietal sinus; 2) division of arachnoid attaching the oculomotor nerve to the tentorial edge and uncus; 3) releasing the arachnoid between the anterior choroidal artery and uncus; and 4) following the oculomotor nerve to its origin.The video can be found here: https://youtu.be/7ZuK-ewNo6w.

Research paper thumbnail of E-143 Embolization of spinal dural arteriovenous fistula: nBCA is superior to onyx embolization

Electronic Poster Abstracts, 2020

Research paper thumbnail of Transradial cerebral angiography becomes more efficient than transfemoral angiography: lessons from 500 consecutive angiograms

Journal of NeuroInterventional Surgery

BackgroundTransradial arterial access (TRA) for cerebral diagnostic angiography is associated wit... more BackgroundTransradial arterial access (TRA) for cerebral diagnostic angiography is associated with fewer access site complications than transfemoral access (TFA). However, concerns about increased procedure time and radiation exposure with TRA may slow its adoption. Our objective was to measure TRA rates of success and fluoroscopy time per vessel after ‘radial-first’ adoption and to compare these rates to those obtained with TFA.MethodsWe examined 500 consecutive cerebral angiograms on an intent-to-treat basis during the first full year of radial-first adoption, recording patient and procedural characteristics and outcomes.ResultsOver a 9-month period at a single center, 457 of 500 angiograms (91.4%) were performed with intent-to-treat via TRA, and 431 cases (86.2%) were ultimately performed via TRA. One patient (0.2%) experienced a temporary neurologic deficit in the TRA group, and none (0%) did in the TFA group (p=0.80). The mean±SD fluoroscopy time per vessel decreased significan...

Research paper thumbnail of Transradial cerebral angiography becomes more efficient than transfemoral angiography: lessons from 500 consecutive angiograms

Journal of NeuroInterventional Surgery, 2021

Background Transradial arterial access (TRA) for cerebral diagnostic angiography is associated wi... more Background Transradial arterial access (TRA) for cerebral diagnostic angiography is associated with fewer access site complications than transfemoral access (TFA). However, concerns about increased procedure time and radiation exposure with TRA may slow its adoption. Our objective was to measure TRA rates of success and fluoroscopy time per vessel after ‘radial-first’ adoption and to compare these rates to those obtained with TFA. Methods We examined 500 consecutive cerebral angiograms on an intent-to-treat basis during the first full year of radial-first adoption, recording patient and procedural characteristics and outcomes. Results Over a 9-month period at a single center, 457 of 500 angiograms (91.4%) were performed with intent-to-treat via TRA, and 431 cases (86.2%) were ultimately performed via TRA. One patient (0.2%) experienced a temporary neurologic deficit in the TRA group, and none (0%) did in the TFA group (p=0.80). The mean±SD fluoroscopy time per vessel decreased signi...

Research paper thumbnail of Surgical Anatomy of the Brainstem

Research paper thumbnail of A propensity-adjusted comparison of middle meningeal artery embolization versus conventional therapy for chronic subdural hematomas

Journal of Neurosurgery, 2021

OBJECTIVEMiddle meningeal artery (MMA) embolization is a promising treatment strategy for chronic... more OBJECTIVEMiddle meningeal artery (MMA) embolization is a promising treatment strategy for chronic subdural hematomas (cSDHs). However, studies comparing MMA embolization and conventional therapy (surgical intervention and conservative management) are limited. The authors aimed to compare MMA embolization versus conventional therapy for cSDHs using a propensity-adjusted analysis.METHODSA retrospective study of all patients with cSDH who presented to a large tertiary center over a 2-year period was performed. MMA embolization was compared with surgical intervention and conservative management. Neurological outcome was assessed using the modified Rankin Scale (mRS). A propensity-adjusted analysis compared MMA embolization versus surgery and conservative management for all individual cSDHs. Primary outcomes included change in hematoma diameter, treatment failure, and complete resolution at last follow-up.RESULTSA total of 231 patients with cSDH met the inclusion criteria. Of these, 35 (...

Research paper thumbnail of Surgery of the Brainstem

Surgery of the Brainstem, 2020

Research paper thumbnail of Avoiding the Radial Paradox: Neuroendovascular Femoral Access Outcomes After Radial Access Adoption

Neurosurgery, 2021

BACKGROUND Transradial access (TRA) for neuroendovascular procedures is increasing in prevalence.... more BACKGROUND Transradial access (TRA) for neuroendovascular procedures is increasing in prevalence. The safety benefits of TRA at a patient level may be offset at a population level by a paradoxical increase in transfemoral access (TFA) vascular access site complications (VASCs), the so-called "radial paradox." OBJECTIVE To study the effect of TRA adoption on TFA performance and outcomes in neuroendovascular procedures. METHODS Data were collected for all procedures performed over a 10-mo period after radial adoption at a single center. RESULTS Over the study period, 1084 procedures were performed, including 719 (66.3%) with an intent to treat by TRA and 365 (33.7%) with an intent to treat by TFA. Thirty-two cases (4.4%) crossed over from TRA to TFA, and 2 cases (0.5%) crossed over from TFA to TRA. TFA was performed in older patients (mean [standard deviation] TFA, 63 [15] vs TRA, 56 [16] years) using larger sheath sizes (≥7 French; TFA, 56.2% vs TRA, 2.3%) (P < .001 for both comparisons). Overall, 29 VASCs occurred (2.7%), including 27 minor (TFA, 4.6% [18/395] vs TRA, 1.3% [9/689], P = .002) and 2 major (TFA, 0.3% [1/395] vs TRA, 0.1% [1/689], P > .99) complications. Independent predictors of VASC included TFA (OR 2.8, 95% confidence interval [CI] 1.1-7.4) and use of dual antiplatelet therapy (OR 4.2, 95% CI 1.6-11.1). CONCLUSION TFA remains an important access route, despite a predominantly radial paradigm, and is disproportionately used in patients at increased risk for VASCs. TFA proficiency may still be achieved in predominantly radial practices without an increase in femoral complications.

Research paper thumbnail of Percutaneous transorbital direct puncture to obliterate a cavernous sinus dural arteriovenous fistula

Journal of NeuroInterventional Surgery, 2021

Cavernous sinus dural arteriovenous fistulas (CS-DAVF) can have an indolent course, with insidiou... more Cavernous sinus dural arteriovenous fistulas (CS-DAVF) can have an indolent course, with insidious onset, but still showing a high likelihood of spontaneous resolution.1 Nevertheless, symptoms in a subset of patients evolve more rapidly, with malignant signs on imaging, warranting intervention.2 We report on a patient in his 40s presenting with redness and proptosis of the right eye, intermittent blurred vision and diplopia. Once ophthalmological examination revealed increased intraocular pressure and imaging showed cortical venous congestion, the decision was made to obliterate a CS-DAVF involving the posteromedial right cavernous sinus.Multiple arteries including branches of the ascending pharyngeal artery, occipital artery and bilateral meningohypophyseal trunks supplied the fistula. Once transarterial embolization was deemed unsafe and both inferior petrosal sinuses did not grant access to the right cavernous sinus, a direct puncture to the cavernous sinus was performed to succe...

Research paper thumbnail of Safety and Feasibility of Out-of-Bed Mobilization for Patients With External Ventricular Drains in a Neurosurgical Intensive Care Unit

Journal of Acute Care Physical Therapy, 2018

Introduction: Prolonged bed rest is a frequent problem for patients with critical illness that ma... more Introduction: Prolonged bed rest is a frequent problem for patients with critical illness that may negatively impact survival, quality of life, and medical care cost. Patients with critical neurologic problems are often kept on bed rest or only cleared to perform bed-based activities because of the inherent risk of displacing or damaging intracranial monitoring devices such as the external ventricular drains (EVDs) during activity. Specific recommendations for out-of-bed (OOB) mobilization of such patients are lacking. Purpose: To review the occurrence of adverse events related to OOB mobilization in patients with EVDs. Methods: This was a retrospective study. Data from all adult patients with an EVD and medical clearance for OOB physical therapy (PT) from October 2014 to November 2016 were analyzed. Results: Eighteen patients with EVDs received 108 interventions of OOB PT sessions during this period. No catheter-related mechanical complications occurred during or immediately following the sessions. No serious adverse events were recorded. Minor adverse events included transient dizziness, headache, episodes of hypertension, and hypotension. Vital signs showed no clinically relevant variations before and after the sessions. Conclusions: OOB mobilization was feasible and safe in this group of patients. The effect on morbidity and survival should be further investigated in a larger prospective study.

Research paper thumbnail of Foramen Magnum Meningiomas: Surgical Management of 25 Cases

Journal of Neurological Surgery Part B: Skull Base, 2012

Research paper thumbnail of Molecular genetics of familial cerebral cavernous malformations

Neurosurgical Focus, 2006

✓Cerebral cavernous malformations (CMs) are angiographically occult neurovascular lesions that co... more ✓Cerebral cavernous malformations (CMs) are angiographically occult neurovascular lesions that consist of enlarged vascular channels without intervening normal parenchyma. Cavernous malformations can occur as sporadic or auto-somal-dominant inherited conditions. Approximately 50% of Hispanic patients with cerebral CMs have the familial form, compared with 10 to 20% of Caucasian patients. There is no difference in the pathological findings or presentation in the sporadic and familial forms. To date, familial CMs have been attributed to mutations at three different loci: CCM1 on 7q21.2, CCM2 on 7p15-p13, or CCM3 on 3q25.2-q27. The authors summarize the current understanding of the molecular events underlying familial CMs.

Research paper thumbnail of Endovascular Aneurysm Treatment

Introduction to Vascular Neurosurgery, 2022

Research paper thumbnail of Stent-Assisted Coiling of a Sidewall Aneurysm of the Distal Middle Cerebral Artery: 2-Dimensional Operative Video

Operative Neurosurgery, 2020

Sidewall aneurysm treatment often requires complex management strategies. These can include advan... more Sidewall aneurysm treatment often requires complex management strategies. These can include advanced clipping techniques or stent-assisted coiling techniques. Endovascular coiling alone has been associated with high recurrence rates and is often not feasible.1-4 Flow-diversion embolization has recently become a standard of care for many aneurysms, demonstrating high occlusion rates.4,5 However, the third generation of coil-assist stents can be delivered with 0.0165” microcatheters, being an ideal adjunct to manage this group of aneurysms in more distal locations. In this video, a 16-yr-old teenager with Parry-Romberg syndrome and congenital adrenal hyperplasia had an incidental finding of a 6.5-mm sidewall aneurysm arising off the angular branch of the left middle cerebral artery, found during the work-up of complex partial seizures. The patient consented to the procedure. Due to his young age and aneurysm size, a decision was made to treat the aneurysm through an endovascular appro...

Research paper thumbnail of Controversies in Neurosurgery II

A world-class team of neurosurgeons tackles a broad spectrum of current neurosurgical issues in t... more A world-class team of neurosurgeons tackles a broad spectrum of current neurosurgical issues in this unique book, where readers get practical advice and frank commentary on the pros and cons of numerous techniques and methods of approach. With more than 100 internationally renowned contributors, it demonstrates the diversity of approaches to any one clinical problem, reflecting real-life situations where several treatment alternatives may be acceptable.

Research paper thumbnail of Schwanoma Vestibular de Crescimento Rápido

JBNC - JORNAL BRASILEIRO DE NEUROCIRURGIA, 2018

A história natural dos schwanomas vestibulares ainda não é totalmente conhecida, mas a maioria de... more A história natural dos schwanomas vestibulares ainda não é totalmente conhecida, mas a maioria destas lesões tende ao crescimento lento, algumas vezes sem qualquer manifestação clínica durante toda a vida do indivíduo, sendo em ocasiões achado de autópsias. Consideráveis avanços no conhecimento da anatomia da base do crânio, assim como os recursos tecnológicos de eletrofisiologia, como a monitorização intra-operatória têm possibilitado índices crescentes de preservação funcional do nervo facial e da audição. Devido a isso, a ressecção cirúrgica completa da lesão permanece sendo o tratamento de escolha quando possível. No entanto, em casos selecionados, o tratamento conservador é uma opção muito bem aceita, desde que haja um seguimento radiológico estrito. Opções terapêuticas como a radiocirurgia são também válidas e devem sempre ser consideradas no armamentarium neurocirúrgico. Novos estudos com quimioterápicos (bevacizumab) também podem mudar a conduta referente às indicações cirúr...

Research paper thumbnail of Surgical approaches for the lateral mesencephalic sulcus

Journal of Neurosurgery, 2019

OBJECTIVEThe brainstem is a compact, delicate structure. The surgeon must have good anatomical kn... more OBJECTIVEThe brainstem is a compact, delicate structure. The surgeon must have good anatomical knowledge of the safe entry points to safely resect intrinsic lesions. Lesions located at the lateral midbrain surface are better approached through the lateral mesencephalic sulcus (LMS). The goal of this study was to compare the surgical exposure to the LMS provided by the subtemporal (ST) approach and the paramedian and extreme-lateral variants of the supracerebellar infratentorial (SCIT) approach.METHODSThese 3 approaches were used in 10 cadaveric heads. The authors performed measurements of predetermined points by using a neuronavigation system. Areas of microsurgical exposure and angles of the approaches were determined. Statistical analysis was performed to identify significant differences in the respective exposures.RESULTSThe surgical exposure was similar for the different approaches—369.8 ± 70.1 mm2 for the ST; 341.2 ± 71.2 mm2 for the SCIT paramedian variant; and 312.0 ± 79.3 mm...

Research paper thumbnail of Accessing the Anterior Mesencephalic Zone: Orbitozygomatic Versus Subtemporal Approach

World neurosurgery, Jan 7, 2018

Despite the latest developments in microsurgery, electrophysiological monitoring, and neuroimagin... more Despite the latest developments in microsurgery, electrophysiological monitoring, and neuroimaging, the surgical management of intrinsic brainstem lesions remains challenging. Several safe entry points have been described to access the different surfaces of the brainstem. Knowledge of this entry zone anatomy is critical to performing a safe and less morbid approach. To access the anterior midbrain surface, a well-known entry point is the anterior mesencephalic (AM) zone. Our aim was to quantify surgical AM zone exposure through the orbitozygomatic (OZ) and subtemporal (ST) approaches. We also analyzed the angular exposure along the horizontal and vertical axis angles for the AM zone. Ten cadaveric heads were dissected using the OZ and ST approaches for anterior midbrain surface exposure. A neuronavigation system was used to determine the 3-dimensional coordinates. The area of surgical exposure, angular exposure, and anatomical limits of each craniotomy were evaluated and determined ...

Research paper thumbnail of Potential application of a handheld confocal endomicroscope imaging system using a variety of fluorophores in experimental gliomas and normal brain

Neurosurgical Focus, 2014

Object The authors sought to assess the feasibility of a handheld visible-wavelength confocal end... more Object The authors sought to assess the feasibility of a handheld visible-wavelength confocal endomicroscope imaging system (Optiscan 5.1, Optiscan Pty., Ltd.) using a variety of rapid-acting fluorophores to provide histological information on gliomas, tumor margins, and normal brain in animal models. Methods Mice (n = 25) implanted with GL261 cells were used to image fluorescein sodium (FNa), 5-aminolevulinic acid (5-ALA), acridine orange (AO), acriflavine (AF), and cresyl violet (CV). A U251 glioma xenograft model in rats (n = 5) was used to image sulforhodamine 101 (SR101). A swine (n = 3) model with AO was used to identify confocal features of normal brain. Images of normal brain, obvious tumor, and peritumoral zones were collected using the handheld confocal endomicroscope. Histological samples were acquired through biopsies from matched imaging areas. Samples were visualized with a benchtop confocal microscope. Histopathological features in corresponding confocal images and ph...

Research paper thumbnail of Aplasia of the Anterior Arch of Atlas Associated With Multiple Congenital Disorders

Neurosurgery, 2011

BACKGROUND AND IMPORTANCE Congenital clefts and aplasias of the atlas vertebra are rare. A nonfus... more BACKGROUND AND IMPORTANCE Congenital clefts and aplasias of the atlas vertebra are rare. A nonfused posterior arch occurs in 4% of the population; in contrast, a nonfused anterior arch occurs in only 0.1%. To the best of our knowledge, this is the first description of the combination of anterior arch aplasia and a cleft of the posterior arch of the atlas associated with Klippel-Feil and Treacher-Collins syndromes and Sprengel deformity. CLINICAL PRESENTATION An 11-year-old girl presented with neck pain and symptoms of myelopathy, including upper- and lower-extremity paresthesia. Computed tomography revealed significant congenital bony anomalies of the cervical spine, with congenital fusion of C2 through C5. There was aplasia of the anterior ring of C1 (A 2.3-cm gap was present within the anterior aspect of the lateral masses). The posterior elements of C3 and C4 were fused, and signs of Sprengel deformity were present. Magnetic resonance imaging revealed effacement of the ventral ce...

Research paper thumbnail of The pretemporal approach to anterolateral midbrain cavernous malformations

Neurosurgical Focus: Video, 2019

Operating on the anterolateral midbrain is challenging due to limited surgical freedom provided b... more Operating on the anterolateral midbrain is challenging due to limited surgical freedom provided by classic approaches and restraints imposed by the basilar artery apex and branches, their perforators, and the oculomotor nerve (Abla et al., 2011; Bricolo and Turazzi, 1995; Cavalcanti et al., 2016).This video demonstrates the benefits provided by the pretemporal approach for resection of an anterolateral mesencephalic cavernous malformation (Chaddad-Neto et al., 2014; de Oliveira et al., 1995). Four steps are well demonstrated in the video: 1) section of temporal pole veins to the sphenoparietal sinus; 2) division of arachnoid attaching the oculomotor nerve to the tentorial edge and uncus; 3) releasing the arachnoid between the anterior choroidal artery and uncus; and 4) following the oculomotor nerve to its origin.The video can be found here: https://youtu.be/7ZuK-ewNo6w.

Research paper thumbnail of E-143 Embolization of spinal dural arteriovenous fistula: nBCA is superior to onyx embolization

Electronic Poster Abstracts, 2020

Research paper thumbnail of Transradial cerebral angiography becomes more efficient than transfemoral angiography: lessons from 500 consecutive angiograms

Journal of NeuroInterventional Surgery

BackgroundTransradial arterial access (TRA) for cerebral diagnostic angiography is associated wit... more BackgroundTransradial arterial access (TRA) for cerebral diagnostic angiography is associated with fewer access site complications than transfemoral access (TFA). However, concerns about increased procedure time and radiation exposure with TRA may slow its adoption. Our objective was to measure TRA rates of success and fluoroscopy time per vessel after ‘radial-first’ adoption and to compare these rates to those obtained with TFA.MethodsWe examined 500 consecutive cerebral angiograms on an intent-to-treat basis during the first full year of radial-first adoption, recording patient and procedural characteristics and outcomes.ResultsOver a 9-month period at a single center, 457 of 500 angiograms (91.4%) were performed with intent-to-treat via TRA, and 431 cases (86.2%) were ultimately performed via TRA. One patient (0.2%) experienced a temporary neurologic deficit in the TRA group, and none (0%) did in the TFA group (p=0.80). The mean±SD fluoroscopy time per vessel decreased significan...

Research paper thumbnail of Transradial cerebral angiography becomes more efficient than transfemoral angiography: lessons from 500 consecutive angiograms

Journal of NeuroInterventional Surgery, 2021

Background Transradial arterial access (TRA) for cerebral diagnostic angiography is associated wi... more Background Transradial arterial access (TRA) for cerebral diagnostic angiography is associated with fewer access site complications than transfemoral access (TFA). However, concerns about increased procedure time and radiation exposure with TRA may slow its adoption. Our objective was to measure TRA rates of success and fluoroscopy time per vessel after ‘radial-first’ adoption and to compare these rates to those obtained with TFA. Methods We examined 500 consecutive cerebral angiograms on an intent-to-treat basis during the first full year of radial-first adoption, recording patient and procedural characteristics and outcomes. Results Over a 9-month period at a single center, 457 of 500 angiograms (91.4%) were performed with intent-to-treat via TRA, and 431 cases (86.2%) were ultimately performed via TRA. One patient (0.2%) experienced a temporary neurologic deficit in the TRA group, and none (0%) did in the TFA group (p=0.80). The mean±SD fluoroscopy time per vessel decreased signi...