- Neurosurgeon, with specialty in vascular neurosurgery, working at a main reference center and involved in research and teaching activities.edit
Research Interests: Cardiology, Surgery, Neurosurgery, Medicine, Internal Medicine, and 15 moreIschemia, Cerebrovascular diseases, Brain Ischemia, Artery, Angiography, Myocardial Infarction, Occlusion, Anastomosis, Middle Cerebral Artery, Internal Carotid Artery, Carotid Artery Stenosis, Revascularization, Hemiparesis, cerebral arteries, and superficial temporal artery
Background Paraclinoid aneurysms represent a challenge for neurosurgeons due to the anatomical complexity of this region. Then, innovative techniques such as the extradural sphenoid ridge approach are suitable for a safe microsurgical... more
Background Paraclinoid aneurysms represent a challenge for neurosurgeons due to the anatomical complexity of this region. Then, innovative techniques such as the extradural sphenoid ridge approach are suitable for a safe microsurgical clipping. Method A description of the surgical technique was made by the senior author, a vascular neurosurgeon experienced with the use of this approach in the management of paraclinoid aneurysms exemplified through a clinical case. Conclusion Microsurgical clipping through an extradural sphenoid ridge keyhole approach for small and midsize paraclinoid aneurysms is an excellent treatment modality with good clinical and surgical results.
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The arachnoid knife is a useful instrument when performing a variety of neurosurgical procedures, for example, while opening the sylvian fissure or basal arachnoid bridges in the pterional approach or during the peripheral delimitation... more
The arachnoid knife is a useful instrument when performing a variety of neurosurgical procedures, for example, while opening the sylvian fissure or basal arachnoid bridges in the pterional approach or during the peripheral delimitation and excision of a cortical AVM. At present, there exists a wide variety of arachnoid knives made from different materials (stainless steel, titanium, or diamond-tipped); however, most of these instruments are expensive and may become dull with continuous use or bad handling. In this article, we report the use and advantages of an arachnoid knife from a simple hypodermic needle. In the last 6 years, we have used this technique to open the arachnoid layer in more than 350 neurosurgical procedures. Furthermore, it can be used to perform sharp arteriotomies during bypass procedures or to open the dura mater over bone structures. To date, no complication arising from this simple technique has been documented. A standard hypodermic needle can be used in the operating room as a practical arachnoid knife. It has the characteristics of being effective, low-cost, and available worldwide.
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Research Interests: Microsurgery, Evolution, Medicine, Hydrocephalus, Complication, and 15 moreHumans, Female, Male, Clinical Sciences, Aged, Middle Aged, Adult, Group, Anosmia, Anterior communicating artery, Mortality rate, Neurologic Examination, glasgow outcome scale, Intracranial aneurysm, and Intraoperative complications
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ABSTRACT Effective treatment of cerebral vasospasm is still a matter of concern in clinical neurosurgery. In refractory cases, the use of intraarterial vasodilators as papaverin or even mechanical angioplasty has been recommended.... more
ABSTRACT Effective treatment of cerebral vasospasm is still a matter of concern in clinical neurosurgery. In refractory cases, the use of intraarterial vasodilators as papaverin or even mechanical angioplasty has been recommended. Experience with intraarterial nimodipine has been seldom reported. From March to November 2004, 23 patients underwent what we define as “chemical angioplasty,” using repeated doses of intraarterial nimodipine for treating refractory vasospasm to other therapeutic modalities. A microcatheter was positioned in the internal carotid artery or the vertebrobasilar system as close as possible to the spastic area. A single 200 mg injection was completed each time until circulation improved or a 1200 mg dose perday was reached. All patients were evaluated using the modified 6-point Rankin scale after the procedure and during neurological follow up. The chemical angioplasty was repeated daily until the vasospasm period was surpassed or there was a failure of the technique and low-density areas (LDA) on the CT scan appeared. The response to this treatment was considered good in seventeen patients (symptomatic vasospasm disappeared with improvement on the Rankin scale), regular in three (symptomatic vasospasm without low-density areas on CT scan), and bad in three (appearance of lowdensity areas on CT scan). It was demonstrated that intraarterial nimodipine decreases the transit time in angiography and improves the cerebral blood volume in the MRI-perfusion sequence without a significant change in the mean transit time. “Chemical” angioplasty with nimodipine can be used repeatedly in some patients with severe vasospasm to prevent the appearance of lowdensity areas on CT scan before mechanical angioplasty is considered.
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Research Interests: Humanities and Medicine
Introduccion. Los aneurismas del tope de la arteria basilar representan cerca del 50% de los aneurismas de la circulacion posterior. En la actualidad a pesar de los avances en el tratamiento endovascular, los indices de recanalizacion... more
Introduccion. Los aneurismas del tope de la arteria basilar representan cerca del 50% de los aneurismas de la circulacion posterior. En la actualidad a pesar de los avances en el tratamiento endovascular, los indices de recanalizacion permanecen altos, con mayor riesgo de resangrado a largo plazo. Material y Metodos. Se realizo un estudio retrospectivo de una base de datos llevada de forma prospectiva de todos los aneurismas de la bifurcacion basilar operados en el Instituto Nacional de Neurologia “Manuel Velasco Suarez” de la Ciudad de Mexico en el periodo de 1997-2019. Se analizo la informacion demogra- fica y los resultados quirurgicos. Ademas, se revisaron los aspectos anatomicos basicos y los principales abordajes empleados para tratar estos aneurismas. Resultados. Los aneurismas del tope de la basilar representaron el 1.73% de un total de 1670 aneurismas operados y el 47.5% de los aneurismas de la circulacion posterior (29 casos). Fueron mas frecuentes en el sexo femenino con una relacion 1.2:1. La edad promedio fue de 49.3 anos (rango 22-70 anos). Solo se operaron pacientes con grado neurologico 1-3 de Hunt y Kosnik. La mayor parte fueron aneurismas menores de 10 mm. El 75.8% (n=22) de los casos se originaron en una bifurcacion en posicion normal. Se observo una asociacion con aneurismas multiples en el 37.9% de los casos. La mayor parte (55.1%) presentaron un domo con direccion superior y el 20% fueronaneurismas grandes o gigantes. El abordaje mas utilizado fue el pterional pretemporal. El indice de oclusion total fue del 82.7%. En el seguimiento a 6 meses, 25 pacientes (86%) tuvieron una puntuacion de 0-2 en la escalamodificada de Rankin. La mortalidad global fue del 6.8%. Los resultados mas pobres se obtuvieron en pacientes con aneurismas gigantes y en aquellos que desarrollaron vasoespasmo sintomatico. Conclusiones. La microcirugia ofrece una opcion viable de tratamiento para aneurismas del tope de la basilar. Cuando se tratan en centros de referencia se obtienen resultados quirurgicos muy aceptables e indices de oclusion mayoral obtenido por terapia endovascular.
Research Interests: Humanities and Medicine
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Brainstem cavernous malformation (BCM) account for 8-22% of all intracranial cavernomas. Currently, they can be treated microsurgically or conservative but it is still difficult to choose the best treatment for each patient. The main... more
Brainstem cavernous malformation (BCM) account for 8-22% of all intracranial cavernomas. Currently, they can be treated microsurgically or conservative but it is still difficult to choose the best treatment for each patient. The main objective of our series was to evaluate the long-term functional outcome and recurrence in patients with BCM treated with conservative or surgical treatments. Hypothesis: We assessed the hypothesis that surgical and conservative treatments are associated with different functional outcome and re-hemorrhage rate in long-term follow-up. Methods: In this non-randomized, clinical series, we compared the clinical and radiological findings of patients with their first hemorrhage secondary to confirmed BCM, treated in a tertiary neurological center, during a twenty five- year period. Treatment of each patient was selected by the attending physician and consisted of either conservative or surgical evacuation of BCM. The primary end-points were recurrent hemorrhage and functional outcome. Favorable prognosis was defined as modified Rankin scale (mRs) of 0 to 2. Results: From January of 1990 to July of 2015; 99 patients with BCM hemorrhage were treated (59 [59,6%] female; mean age 37± 13 years). 37 patients (37,4%) were surgically treated and 62 (62,6%) received conservative treatment. During the follow-up; 20 patients in the medical group (median time of recurrence: 34,5 months; IQR: 13,75-93) and 4 patients in the surgical group (median time of recurrence: 22 months; IQR: 9-46,5) had a recurrence (OR: 0,255; 95% IC: 0,079-0,817), with a cumulative incidence of 5,1 per 100 years-person and 3,96 per 100 years-person respectively. Because of rebleeding, 11 patients of the conservative group were taken to surgery and 3 of the surgical group were to required re-intervention. At the end of follow-up (median: 51 months; IQR: 19-104) 51 patients remained in the conservative group and 28 (54,9%) had a favorable mRs. 48 patients remained in the surgical group and 27 (56,2%) had a favorable mRs (OR:0,94 95% IC: 0,42-2,09). Conclusion: Despite a significant high recurrent hemorrhage rate was observed in conservative treated patients, we did not found difference in clinical outcome between both groups of patients with BCM.
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Ischemic cerebrovascular disease is an important cause of morbidity and mortality. One common final pathway in neuronal ischemic damage is the uncontrolled influx of calcium into the cell, mediated by voltage dependent channels or... more
Ischemic cerebrovascular disease is an important cause of morbidity and mortality. One common final pathway in neuronal ischemic damage is the uncontrolled influx of calcium into the cell, mediated by voltage dependent channels or activation of the NMDA (N-methyl D-aspartate) receptor. The therapeutic utility of a non-competitive NMDA blocker (MK-801, 2 mg/kg i.p.), to prevent the neuronal ischemic damage in an experimental middle cerebral artery occlusion model has been tested. The drug was administered 10 minutes before (group 3) and one hour after the arterial occlusion (group 4), and the results were compared with a group in which no medicament was utilized (group 2) and a control group (sham operation, group 1). MK-801 reduced significantly the area of infarction in relation to the control group (p < 0.05), mainly if the MK-801 was administered before the occlusion (group 3). These results suggest that MK-801 may be useful for the prevention of the neuronal ischemic damage caused by focal ischemia. However, before recommending its use in humans, all the possible collateral effects must be defined.
Research Interests: Medicine, Ischemia, Pubmed, Animals, Anesthesia, and 5 moreBrain Ischemia, Rats, Time Factors, Occlusion, and NMDA receptor
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Background Even when there is a CT scan classification for the evaluation of subarachnoid haemorrhage (SAH) and clinical outcome (Fisher’s scale), until now, there is not an angiographic scale currently in use that correlates the... more
Background Even when there is a CT scan classification for the evaluation of subarachnoid haemorrhage (SAH) and clinical outcome (Fisher’s scale), until now, there is not an angiographic scale currently in use that correlates the vasospasm extent with the clinical outcome.
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Reported are 15 cases of children who suffered injuries to their posterior fossa and the subsequent formation of hematomas and their treatment by the physicians in the Neurosurgical Department of the Traumatology Hospital "Magdalena de... more
Reported are 15 cases of children who suffered injuries to their posterior fossa and the subsequent formation of hematomas and their treatment by the physicians in the Neurosurgical Department of the Traumatology Hospital "Magdalena de las Salinas". Of the 15 cases, 11 had epidural hematomas (three of them with supratentorial extensions), one was subdural, two were cerebellar and another of the brainstem. Seven were considered acute, five were subacute and three were chronic. During their admittance to the hospital, five of the patients were in a state of coma, another five were sleepy or confused and the remaining five were conscious. Three of the patients were conservatively treated, two of which had sequelae or were moderately handicapped. Twelve of the patients were surgically intervened suboccipitally, eleven of which successfully recovered and one of which died. A history of brain injury, occipital fracture and signs of posterior fossa lesions lead to suspect the presence of posterior fossa hematoma.
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✓ Vascular complications after percutaneous injection procedures for relief of trigeminal neuralgia are varied, ranging from puncture of arterial or venous structures to carotid-cavernous fistulas. The authors present a patient in whom an... more
✓ Vascular complications after percutaneous injection procedures for relief of trigeminal neuralgia are varied, ranging from puncture of arterial or venous structures to carotid-cavernous fistulas. The authors present a patient in whom an external carotid artery fistula occurred after a microcompression procedure for the treatment of a left-sided trigeminal neuralgia. This is believed to be the first case of this complication secondary to a percutaneous injection procedure for relief of facial pain.
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The use of intraoperative fluorescence has proven to be a useful tool in multiple neurosurgical procedures with a potential utility in treating arteriovenous malformations (AVMs). The aim of this study was to characterize dynamic changes... more
The use of intraoperative fluorescence has proven to be a useful tool in multiple neurosurgical procedures with a potential utility in treating arteriovenous malformations (AVMs). The aim of this study was to characterize dynamic changes of an AVM using a microscope-integrated technique at the moment of performing an intraoperative Sodium fluorescein videoangiography (FL-VAG) at each of the resection phases. Our study at the National Institute of Neurology and Neurosurgery-Mexico City, prospectively recruited twelve patients harboring an AVM, using FL-VAG as an ancillary technique for the resection of the lesion. We analyzed the transit time (TT) of fluorescein in arterial feeders (TTa) and draining veins (TTv) during the different stages of resection. To achieve this, we recorded three values of the transit time of fluorescein (TTa, initial TTv, final TTv); when final TTv was markedly slower than initial TTv, we hypothesized that the nidus was devascularized enough and could be safely removed. No mortality or morbidity was related to the use of fluorescein. In most cases, the TT values of arterial feeders and draining veins allowed an easier distinction between them. At advanced stages of resection, the FL-VAG assesses the increase in TTv (venous blood is slower or absent), suggesting that most feeding arteries had been obliterated, indicating the appropriate moment for nidus removal. The optimal dose of fluorescein was a 75 mg bolus followed by and injection of 20 ml of saline solution. This simple technique allows a distinction of normal from abnormal flow in draining vessels, and might aid the surgeon to decide when the nidus can finally be safely removed. This is the first study prospectively evaluating this technique, and proposes an ideal dose for brain AVM surgery, in contrast with doses used in tumor cases.
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Research Interests: Surgery, Neurosurgery, Microsurgery, Treatment Outcome, Medicine, and 15 moreCase Report, Humans, Female, Male, Clinical Sciences, Aged, Middle Aged, Posterior Fossa, Adult, Retrospective Studies, Intracranial Arteriovenous Malformations, Microvascular Decompression, Decompression, Neurosciences, and Neuralgia
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Background: The middle cerebral artery (MCA) is a common site of cerebral aneurysms and 82.6% occur at the bifurcation. When surgery is selected as a therapeutic option, it intends to clip the neck completely because if some remnant... more
Background: The middle cerebral artery (MCA) is a common site of cerebral aneurysms and 82.6% occur at the bifurcation. When surgery is selected as a therapeutic option, it intends to clip the neck completely because if some remnant occurs, there exists the possibility of regrowth and bleeding in the short- or long-term. Methods: We analyzed one drawback of the fenestrated clips of Yasargil and Sugita types to occlude the neck totally at a specific point formed by the union of the fenestra with the blades, creating a triangular space where the aneurysm can protrude, giving place to a remnant that can lead to a future recurrence and rebleeding. We show two cases of ruptured MCA aneurysms in which a cross-clipping technique occluded a broad base and dysmorphic aneurysm using straight fenestrated clips. Results: In both cases (one using a Yasargil clip and the other with a Sugita clip), a small remnant was visualized when fluorescein videoangiography (FL-VAG) was used. In both cases, t...
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Background: Lhermitte-Duclos disease (LDD) or dysplastic gangliocytoma of the posterior fossa is a slow-growing and extremely rare mass lesion that involves the Purkinje neurons and the granular layer of the cerebellum. It is... more
Background: Lhermitte-Duclos disease (LDD) or dysplastic gangliocytoma of the posterior fossa is a slow-growing and extremely rare mass lesion that involves the Purkinje neurons and the granular layer of the cerebellum. It is characterized by specific neuroradiological features and secondary hydrocephalus. However, documentation of surgical experience is scarce. Case Description: A 54-year-old man with LDD manifesting as progressive headache is presented with vertigo and cerebellar ataxia. Magnetic resonance imaging demonstrated a right cerebellar mass lesion with the characteristic “tiger-striped appearance.” We decided to perform partial resection with reduction of tumor volume improving symptomatology as a result of the mass effect in the posterior fossa. Conclusion: Surgical resection is a good alternative for the management of LDD, especially when neurological compromise exists due to mass effect.
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Background: Anomalies of the middle cerebral artery (MCA) are rare; among the different types of anomalies, the aplastic or twig-like (Ap/T) MCA is extremely rare and has been reported under various names, including aplastic, unfused, or... more
Background: Anomalies of the middle cerebral artery (MCA) are rare; among the different types of anomalies, the aplastic or twig-like (Ap/T) MCA is extremely rare and has been reported under various names, including aplastic, unfused, or rete type anomaly. The occurrence of a brain aneurysm associated with this anatomic variant is an even rare event, and probably their development and rupture are related to hemodynamic stress of the tinny wall of vessels forming the network. Case Description: We present a 43-year-old male patient with an explosive and persistent right orbitofrontal headache. A computed tomography showed a right frontobasal hematoma with intraventricular disruption. Magnetic resonance angiography showed a right MCA aneurysm and what seems to be a MCA trunk stenosis. Cerebral digital subtraction angiography demonstrated a plexiform arterial network and one aneurysm arising from the network. The patient was successfully treated by surgical clipping to evacuate the hema...
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OBJECTIVE Sylvian fissure (SF) arteriovenous malformations (AVMs) are among the most challenging vascular lesions amenable to neurosurgical treatment and account for 10% of all locations. As radiosurgery and endovascular techniques are... more
OBJECTIVE Sylvian fissure (SF) arteriovenous malformations (AVMs) are among the most challenging vascular lesions amenable to neurosurgical treatment and account for 10% of all locations. As radiosurgery and endovascular techniques are increasingly involved in multimodal management protocols, the role of microsurgery needs to be reassessed as a stand-alone technique. The aim of this study was to show that total excision can be achieved with reasonable levels of morbidity and mortality in a real-world setting from a specialized high-volume center. METHODS Forty-three patients with SF AVMs were identified from a series of 577 AVM patients treated microsurgically over a 22-year period. The mean patient age was 33.07 years (range 15–60 years), and there were 22 male and 21 female patients. The mode of presentation was headache in 51.2%, hemorrhage in 34.9%, seizures in 30.2%, and steal phenomenon in 9.3%. The authors analyzed the anatomical basis and angiographic characteristics of such...
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Brainstem cavernous malformations (BSCMs) account for up to 18% of all intracranial cavernous malformations. Due to their complex anatomic location, they represent a significant challenge for neurosurgeons. As such, the identification of... more
Brainstem cavernous malformations (BSCMs) account for up to 18% of all intracranial cavernous malformations. Due to their complex anatomic location, they represent a significant challenge for neurosurgeons. As such, the identification of risk factors associated with negative outcomes is of significant importance. We analyze a series of 50 cases of BSCMs treated surgically in order to identify risk factors for unfavorable outcomes. Patients who underwent surgical resection of BSCM at our institution between 2000 and 2015 were retrospectively reviewed. Univariate and multivariable logistic regression models were used to identify predictors of unfavorable outcomes, defined as those with a modified Rankin score (mRs) of >2. Fifty Latin American patients, with a mean age of 35.85 ± 13.06 years, consisting of 29 females (58%) and 21 males (42%), underwent surgical resection. Mean modified Rankin Scale (mRs) score at admission was 2.6 ± 1.05, and the mean BCSM size was 18.00 ± 7.19 mm. ...
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The results described in this work are part of a larger project. The long term goal of this project is to help physicians predict the hemodynamic changes, and associated risks, caused by different treatment options for brain arteriovenous... more
The results described in this work are part of a larger project. The long term goal of this project is to help physicians predict the hemodynamic changes, and associated risks, caused by different treatment options for brain arteriovenous malformations. First, we need to build a model of the vascular architecture of each specific patient. Our approach to build these models is described in this work. Later we will use the model of the vascular architecture to simulate the velocity and pressure gradients of the blood flowing within the vessels, and the stresses on the blood vessel walls, before and after treatment. We are developing a computer program to describe each blood vessel as a parametric curve, where each point within this curve includes a normal vector that points in the opposite direction of the pressure gradient. The shape of the cross section of the vessel in each point is described as an ellipse. Our program is able to describe the geometry of a blood vessel using as an input a cloud of dots. The program allows us to model any blood vessel, and other tubular structures.
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Research Interests: Cardiology, Medicine, Brain, Humans, Hemodynamics, and 15 moreFemale, Male, Aged, Adult, Blood Flow, Flow Velocity, Cerebral Aneurysms, Cerebral Blood Flow, Blood Flow Velocity, Anterior communicating artery, Brain Diseases, Cerebral Angiography, Cerebral Vasospasm, Carotid Arteries, and Intracranial aneurysm
The results described in this chapter are part of a larger project. The long term goal of this project is to help physicians predict the hemodynamic changes, and associated risks, caused by different treatment options for brain... more
The results described in this chapter are part of a larger project. The long term goal of this project is to help physicians predict the hemodynamic changes, and associated risks, caused by different treatment options for brain arteriovenous malformations. First, we need to build a model of the vascular architecture of each specific patient, our approach to build these models is described in this chapter. Later we will use the model of the vascular architecture to simulate the velocity and pressure gradients of the blood flowing within the vessels, and the stresses on the blood vessel walls, before and after treatment. We are developing a program to describe each blood vessel as a parametric curve, where each point within this curve includes a normal vector that points in the opposite direction of the pressure gradient. The shape of the cross section of the vessel in each point is described as an ellipse. Our program is able to describe the geometry of a blood vessel using as an input a cloud of dots. The program allows us to model any blood vessel, and other tubular structures.