Endoscopic endonasal surgery to treat intrinsic brainstem lesions: correlation between anatomy and surgery.

OBJECTIVE: The endoscopic endonasal approach (EEA) has been proposed as an alternative in the surgical removal of ventral brainstem lesions. However, the feasibility and limitations of this approach to treat such pathologies are still poorly understood. This study aimed to report our experience in five consecutive cases of intrinsic brainstem lesions that were managed via an EEA, as well as the specific anatomy of each case. METHODS: All patients were treated in a single center by a multidisciplinary surgical team between 2015 and 2019. Before surgery, a dedicated anatomical analysis of the brainstem safe entry zone was performed, and proper surgical planning was carried out. Neurophysiological monitoring was used in all cases. Anatomical dissections were performed in three human cadaveric heads using 0° and 30° endoscopes, and specific 3D reconstructions were executed using Amira 3D software. RESULTS: All lesions were located at the level of the ventral brainstem. Specifically, one mesencephalic cavernoma, two pontine ca- vernomas, one pontine gliomas, and one medullary diffuse midline glioma were reported. Cerebrospinal fluid leak was the major complication that occurred in one case (medullary diffuse midline glioma). From an anatomical standpoint, three main safe entry zones were used, namely the anterior mesencephalic zone (AMZ), the peritrigeminal zone (PTZ, used in two cases), and the olivar zone (OZ). Reviewing the literature, 17 cases of various brainstem lesions treated using an EEA were found. CONCLUSIONS: To our knowledge, this was the first preliminary clinical series of intrinsic brainstem lesions treated via an EEA presented in the literature. The EEA can be considered a valid surgical alternative to traditional transcranial approaches to treat selected intra-axial brainstem lesions located at the level of the ventral brainstem. To achieve good results, surgery must involve comprehensive anatomical knowledge, meticulous preoperative surgical planning, and intraoperative neurophysiological moni- toring.

Anaesthetic management in neurosurgery in a patient with Eisenmenger syndrome and Down syndrome. A case report.

Adults patients with congenital heart disease increasingly present for non cardiac surgery. The anesthetic management this type of patients in neurosurgery requires a meticulous surgical anesthetic planning. The need for urgent intervention, with the presence of a congenital heart disease evolved to Eisenmenger syndrome, associated to a difficult airway, is a challenge for the anesthesiologist. The use of dexmedetomidine may be a valid alternative. We present the case of a patient with Down syndrome, and Eisenmenger syndrome who underwent drainage of brain abscess from the emergency department and was subsequently scheduled for reintervention. We compare the different anesthetic techniques used in both procedures, analyzing the implications they had on the main physiopathological alterations presented by the patient.

Anaesthetic management in neurosurgery in a patient with Eisenmenger syndrome and Down syndrome. A case report. / Manejo anestésico en neurocirugía de paciente con síndrome de Eisenmenger y síndrome de Down. Reporte de un caso.

Adults patients with congenital heart disease increasingly present for non cardiac surgery. The anesthetic management this type of patients in neurosurgery requires a meticulous surgical anesthetic planning. The need for urgent intervention, with the presence of a congenital heart disease evolved to Eisenmenger Syndrome, associated to a difficult airway, is a challenge for the anesthesiologist. The use of dexmedetomidine may be a valid alternative. We present the case of a patient with Down syndrome, and Eisenmenger syndrome who underwent drainage of brain abscess from the emergency department and was subsequently scheduled for reintervention. We compare the different anesthetic techniques used in both procedures, analyzing the implications they had on the main physiopathological alterations presented by the patient.

[Intraoperative detection of ischemic brain hypoxia using oxygen tissue pressure microprobes]. / Detección intraoperatoria de hipoxia cerebral isquémica mediante sensores de presión tisular de oxígeno.

OBJECTIVE AND IMPORTANCE: Detection of intraoperative ischemic events could lead to the resolution of their cause and to the prevention of the definitive establishment of a postoperative infarct. We want to illustrate the possibilities that intraoperative monitoring of oxygen tissue pressure (PtiO2) in critical areas during a neurosurgical vascular procedure offers, enhancing its reliability and immediacy in obtaining information about tissue oxygenation status as a marker of ischemia in the vascular territory at risk. CLINICAL PRESENTATION: We report the case of a 32 year-old male with a deep arteriovenous malformation (AVM) localised in the insular region. The patient had been previously treated with radiosurgery without achieving a satisfactory result. INTERVENTION: AVM removal was performed through a transylvian transinsular approach. PtiO2 was monitorised at the temporal pole (reference area) and at the posterior temporal region (risk area). Both probes maintained close tissue oxygenation levels until the last stage of the AVM resection when, during the coagulation of a supposed afferent vessel, a brisk fall of the oxygen tissue pressure in the posterior temporal region was detected. An ischemic infarct in this area was observed postoperatively. CONCLUSIONS: PtiO2 monitoring has a high reliability in the detection of intraoperative tissue hypoxia. Data obtained could lead to early identification of these events and, whatever possible, to resolve this situation preventing the definitive establishment of an ischemic infarct.