[Treatment of a giant serpentine type middle cerebral artery aneurysm with a high-flow bypass from the petrous internal carotid artery]. / Tratamiento de un aneurisma serpentino gigante de arteria cerebral media conbypass de alto flujo desde la arteria carótida interna petrosa.

A case report of a giant serpentine type aneurysm arising from the M1 segment of the middle cerebral artery (MCA) treated with a high-flow external saphenous vein graft from the petrous segment of the internal carotid artery is presented. The steps and challenges of this demanding surgical technique are also described. The elements to be taken into consideration in the indication, design and realization of the bypass surgery in the treatment of the MCA aneurysms are discussed.

[Management and microsurgical treatment of infundibular dilatations of the posterior communicating artery. Series of nine cases and review of the literature]. / Manejo y traramiento microquirurgico de las dilataciones infundibulares de la arteria comunicante posterior. Seri de nueve casos y revision de la literatura.

INTRODUCTION: The infundibular dilatation (ID) of the posterior communicating (PCom) artery is defined as the conic, triangular or infundibular shaped, less than 3mm wide, origin of the PCom artery from the internal carotid artery. The purpose of this paper is to present the personal experience in the microsurgical management of the ID, to review the literature and to propose some algorithms to improve its clinical and microsurgical management. MATERIAL AND METHODS: Nine cases of ID have been operated on through a pterional approach. In four patients with subarachnoid hemorrhage (SAH) the ID was considered as the potential source of the bleeding; in four cases the ID was treated after a SAH due to the rupture of an aneurysm; finally, an ID was treated in patient with diagnosis of pseudoxantoma elasticum. RESULTS: In eight cases the ID was clipped and the Pcom artery subsequently occluded and in the remaining case the ID was associated with a fetal PComA and the ID was reinforced. There were no complications excepting a transitory third cranial nerve paresis. The Glasgow Outcome Scale was 5 in all cases at discharge and one year later. CONCLUSIONS: The true significance of the ID remains unknown, but in some instances it is necessary to consider its management: 1. In patients with ruptured aneurysms submitted to microsurgical clipping and with an ipsilateral ID, the lesion must be explored and treated; 2. In patients with ruptured aneurysms treated with endovascular procedures or harbouring an ID contralateral to a microsurgically treated aneurysm, the microsurgical indication will be done after considering all risk factors; 3. In patients with SAH and an ID as the only potential source of the bleeding there would be an indication for microsurgical exploration; 4. The incidental finding of an ID should be indication for observation in absence of major risk factors.

[Olfactory groove meningiomas. Radical microsurgical treatment through the bifrontal approach]. / Meningiomas del surco olfatorio. Tratamiento microquirúrgico radical por via bifrontal.

OBJECTIVES: To describe the microsurgical technique for the radical removal of olfactory groove meningiomas through the bifrontal approach. To review the diagnostic elements to be taken into account in the selection of the surgical approach to these tumours. MATERIALS AND METHODS: A microsurgical series of 35 olfactory groove meningiomas operated on through a bifrontal craniotomy is reviewed. RESULTS: The mean tumoral volume was 85cc (4.4cm diameter). A relevant peritumoral brain edema was found in 65.7% of cases, hyperostosis in the implantation base in 80% and paranasal sinus invasion in 28.6%. A Sipmson grade 1 resection was achieved in every case. A patient died due to a postoperative pneumonia. Postoperative hospitalization time was between 3 and 20 days and at discharge all patients had a Glasgow Outcome Scale grade 4-5. The mean follow-up was 55.2 months. Two patients had postoperative transient rhinolicuorrhea and an additional patient developed hydrocephalus. An asymptomatic recurrence have been identified in a patient four years after surgery. CONCLUSIONS: In our experience the bifrontal approach allowed the radical removal of huge olfactory groove meningiomas. The microdissection of the anterior cerebral artery A2 segments is possible thanks to the arachnoidal plane between vessels and tumor. Tumoral blood flow is secured by the early approaching of the base of the tumor and preoperative embolization is not necessary. Bifrontal approach allows an aggressive treatment of the hyperostosis, bone infiltration and paranasal sinus invasion. Anterior fossa reconstruction is done using a vascularized periosteal flap.

[Treatment of intrinsic brain tumors located in motor eloquent areas. Results of a protocol based in navigation, tractography and neurophysiological monitoring of cortical and subcortical structures]. / Tratamiento de los tumores cerebrales intrínsecos de áreas motoras elocuentes. Resultados de un protocolo basado en la navegación, tractografía y monitorización neurofisiológica de estructuras corticales y subcorticales.

OBJECTIVES: The role of the microsurgical management of intrinsic brain tumors is to maximize the volumetric resection of the tumoral tissue minimizing the postoperative morbidity. The purpose of our paper has been to study the benefits of an original protocol developed for the microsurgical treatment of tumors located in eloquent motor areas where the navigation and electrical stimulation of motor subcortical pathways have been implemented. MATERIALS AND METHODS: A total of 17 patients operated on for resection of cortical or subcortical tumors in motor areas were included in the series. Preoperative planning for multimodal navigation was done integrating anatomic studies, motor functional MRI (f-MRI) and subcortical pathways volumes generated by diffusion tensor imaging (DTI). Intraoperative neuromonitorization included motor mapping by direct cortical and subcortical electrical stimulation (CS and sCS) and localization of the central sulcus using cortical multipolar electrodes and the N20 wave inversion technique. The location of all cortical and subcortical stimulated points with positive motor response was stored in the navigator and correlated with the cortical or subcortical motor functional structures defined preoperatively. RESULTS: The mean tumoral volumetric resection was 89.1±14.2% of the preoperative volume, with a total resection (≥100%) in twelve patients. Preoperatively a total of 58.8% of the patients had some motor deficit, increasing 24 hours after surgery to 76.5% and decreasing to 41.1% a month later. There was a great correlation between anatomic and functional data, both cortically and subcortically. However, in six cases it was not possible to identify the central sulcus and in many cases fMRI gave contradictory information. A total of 52 cortical points submitted to CS had positive motor response, with a positive correlation of 83.7%. Also, a total of 55 subcortical points had positive motor response, being in these cases 7.3±3.1 mm the mean distance from the stimulated point to the subcortical tract. CONCLUSIONS: The integration of preoperative and intraoperative anatomic and functional studies allows a safe functional resection of the brain tumors located in eloquent areas, compared to the tumoral resection based on anatomic imaging studies. Multimodal navigation allows the integration and correlation among preoperative and intraoperative anatomic and functional data. Cortical motor functional areas are anatomically and functionally located preoperatively thanks to MRI and fMRI and subcortical motor pathways with TDI and tractography. Intraoperative confirmation is done with CS and N20 inversion wave for cortical structures and with sCS for subcortical pathways. With this protocol we achieved a mean of 90% of volumetric resection in cortical and subcortical tumors located in eloquent motor areas with an increase of neurological deficits in the immediate postoperative period that significantly decreased one month later. Ongoing studies will define the safe limits for functional resection taking into account the intraoperative brain shift. Finally, it must be demonstrated if this protocol has any benefit for patients concerning disease free or overall survival.

[Petrous bone fracture. Our experience: 1999-2004]. / Fracturas de peñasco. Nuestra experiencia: 1999-2004.

OBJECTIVE: To review the petrous bone fractures during the last five years (1999-2004) in our hospital, its manage, control, and analysis onf the associated factors. To analyse the managing protocoles and current bibliography. MATERIAL AND METHODS: We review 266 temporal bone fractures, 74 with petrous bone association. We analyse these fractures by sex distribution, injurie severity, otorhinolaryngological clinical findings, production mechanism and radiological findings. The cases are discussed and compared with current bibliography. CONCLUSIONS: Petrous bone fractures must be always suspected in patients with head trauma, specially if it associates severity and otorrhagia. It is necessary a deep colaboration between neurosurgeons, radiologists and otorhinolaryngologists to obtain a good management, control and follow up of the patients.