ABSTRACT: 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.
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.
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.
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.
Neurocirugia (Asturias, Spain) 08/2011; 22(4):301-9. · 0.54 Impact Factor
ABSTRACT: 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.
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.
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.
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.
Neurocirugia (Asturias, Spain) 02/2011; 22(1):23-35. · 0.54 Impact Factor
ABSTRACT: INTRODUCTION: the thermal diffusion flowmetry (TDF) is a technique that allows the measurement of the regional cerebral blood flow (rCBF) through an implanted microprobe in a cerebral region of interest. The monitoring is continuous, real-time and quantitative (ml/100g/min). The purpose of our clinical work has been to show the technical details and preliminary results by using this monitoring technique during the microsurgical management of cerebral aneurysms and along the postoperative period. The aim of the monitoring of the rCBF is to identify and evaluate ischemic events related with the temporary artery clipping or malposition of the final clip. CLINICAL MATERIALS: a total of five patients have been monitored (4 woman and one man with an average age of 50.8 years). Two patients harboured one aneurysm in the middle cerebral artery, other two patients had two aneurysms each one on the internal carotid artery in the exit of the posterior communicating and anterior choroidal artery and the fifth harboured a paraclinoid internal carotid artery aneurysm. All patients were operated on using standard microsurgical techniques through a pterional approach. Surgery was done under neurophysiological monitoring and direct microdoppler fluometry assesment. Just before craniotomy the TDF microprobe was inserted 2.5 cm deep into the white matter through a small burr-hole placed on the coronal line and 2 cm away the midline to measure in the anterior cereral artery vascular sector and 6cm away of the midline to measure in the middle cerebral artery territory. Patients were under continuous monitoring during surgery and along the postoperative period in the recovery unit. A total of 14 temporary artery clippings (between 2-4) with an average total clipping time of 7.2 minutes (ranging 1.6 to 16) and 16 definitive clip replacements (ranging 2 to 8) were done at surgery. Patient with paraclinoid aneurysm was operated on using the retrograde aspiration technique and the internal carotid artery was kept closed 45 mimutes. keeping Some illustrative cases and demonstrative records are presented. CONCLUSIONS: the use of TDF allows a quantitative real-time measurement of the rCBF in the areas of interest monitored during the microsurgical management of the cerebral aneurysms which leads to detect ischemic events helpping to avoid ischemic sequelae. The detection of ischemic events in real time would make possible the use of therapeutic measures ealier and more efficienty.
Neurocirugia (Asturias, Spain) 10/2010; 21(5):373-80. · 0.54 Impact Factor