António Cerejo

Intracranial aneurysm and vasculopathy after surgery and radiation therapy for craniopharyngioma: Case report

OBJECTIVE AND IMPORTANCE This case report illustrates the possible occurrence of intracranial aneurysms after surgery and radiation-induced vasculopathy. CLINICAL PRESENTATION An internal carotid bifurcation aneurysm was diagnosed in a 19-year-old woman in a routine follow-up examination by magnetic resonance imaging 5 years after subtotal removal of a giant cystic craniopharyngioma treated by postoperative external radiotherapy. The presence of the aneurysm was confirmed by angiography. INTERVENTION It was decided to treat the aneurysm by embolization with Guglielmi detachable coiling. However, at the beginning of the procedure, a few weeks after the diagnosis, a dramatic reduction in the carotid artery blood flow was observed, along with signs of thrombosis inside the aneurysm. In light of these findings, the procedure was aborted. Four months later, another angiographic examination confirmed the exclusion of the aneurysm and compensatory flow through the external carotid artery. CONCLUSION During the assessment of patients who have undergone postoperative radiotherapy, the potential for the development of aneurysms and radiation-induced vasculopathy exists and should be kept in mind. Considering the potential for spontaneous thrombosis of these aneurysms, cautious judgment is recommended before making a decision to treat them.

The galea frontalis myofascial flap in anterior fossa CSF leaks.

We report the clinical use of galea frontalis myofascial flaps in the treatment of anterior fossa cerebrospinal fluid leaks after trauma. This flap provides an adequately sized and vascularised barrier between the cranial and nasal cavities through which the cells of the inflammatory response reach the target area. This technique was used in 9 cases with complete success; in 5 out of 9 patients, repair of an anterior cranial base bone defect was also performed with split calvarial bone grafts, harvested from the frontal craniotomy bone. In all patients, neither recurrence of the CSF leakage nor postoperative meningitis or its recurrence were observed.

The infratentorial supracerebellar approach in surgery of lesions of the pineal region

Background: Surgery of pineal region lesions is considered a challenging task, due to the particular relationship of lesions in this location with neural and vascular structures. Few series with a significant experience of dealing with these patients have been reported. Methods: We review our experience using infratentorial supracerebellar approach in the surgery of pineal region, regarding the extension of the removal, postoperative morbidity, and discussing details of the surgical technique. In all cases, a supracerebellar infratentorial approach was used in the semi sitting position. Results: A total of 32 patients were operated in the past 20 years (3 germinomas, 3 teratoma, 3 pineocitoma, 2 pineal tumor of intermediate differentiation, 6 pineoblastomas, 6 low grade astrocytoma, 2 glioblastoma, 2 metastasis, 1 ependymoma, 1 epidermoid tumor, 1 cavernoma, and 2 arachnoid cyst). Total removal was achieved in 15 cases and subtotal extensive removal in 7 patients. In the remaining cases, only partial removal was possible, due to the involved pathological types. There was no surgical mortality and no cases of cerebellar venous infarction. Morbidity consisted of transient ocular movement disturbance in 14 patients, transient ataxia in 3 patients, and 1 case of local cerebrospinal fluid (CSF) fistula with meningitis that required surgical treatment. Conclusion: Supracerebellar infratentorial is a safe approach to lesions in the pineal region, and total or extensive subtotal removal is possible in most cases, with acceptable morbidity.

Surgical Removal of Giant Acoustic Neuromas

OBJECTIVE The authors present the outcome of radical surgical removal of giant acoustic neuromas. METHODS Twenty-nine patients with acoustic neuroma with maximum diameter greater than 40 mm, submitted to surgery between the years 2005 and 2010, were reviewed by a retrospective study. The extension of tumor removal, surgical morbidity, facial nerve function, hearing, and evolution after surgery of preoperative neurologic conditions were the studied parameters. RESULTS All tumors were completely removed by a retrosigmoid approach, without perioperative mortality. As complications related to the surgery, there were three cases of local cerebrospinal fluid leak, one case of nasal cerebrospinal fluid leak, two cases of meningitis, one pseudomeningocele, and one case of transient lower cranial nerve dysfunction. The anatomic integrity of the facial nerve was preserved in 86% and facial function in 72%. In the 21 patients who did not need hypoglossal-facial anastomosis (72%), facial function was excellent or good (HB I-II) in 13 cases (45%), fair (HB III) in 5 cases (17%), and poor (HB IV) in 3 cases (10%). Before surgery, 12 patients (41%) had useful (H2) or moderate (H3) hearing. In 7 of these 12 patients (58%), it was possible to preserve some hearing function (with moderate hearing), after surgical removal of the tumors. Six patients presented with radiologic signs of hydrocephalus, two of them with visual disturbances. Two patients presented with trigeminal neuralgia (one contralateral), three with facial sensory loss and one with swallowing problems, that disappeared after surgery. CONCLUSIONS Total removal of large acoustic neuroma can be achieved by retrosigmoid approach with acceptable morbidity and no mortality. Preoperative neurologic symptoms recovered after surgery in most cases. Facial function preservation was possible in the majority of cases. Even in large tumors, hearing preservation should be attempted if the patient has useful hearing preoperatively.

Monitoring of brain oxygenation in surgery of ruptured middle cerebral artery aneurysms

Background: The occurrence of brain ischemic lesions, due to temporary arterial occlusion or incorrect placement of the definitive clip, is a major complication of aneurysm surgery. Temporary clipping is a current technique during surgery and there is no reliable method of predicting the possibility of ischemia due to extended regional circulatory interruption. Even with careful inspection, misplacement of the definitive clip can be difficult to detect. Brain tissue oxygen concentration (PtiO2) was monitored during surgery of middle cerebral artery (MCA) aneurysm presenting with subarachnoid hemorrhage (SAH), for detection of changes in brain oxygenation due to reduced blood flow, as a predictor of ischemic events, during temporary clipping and after definitive clipping. Methods: PtiO2 was monitored during surgery of 13 patients harboring MCA aneurysms presenting with SAH, using a polarographic microcatheter (Licox, GMS, Kiel, Germany) placed in the territory of MCA. Results A decrease in PtiO2 values was verified in every period of temporary clipping. Brain infarction occurred in 2 patients; in both cases, there was a decrease in PtiO2 greater than 80% from basal value, a minimum value of less than 2 mmHg persisting for 2 or more minutes during temporary clipping, and an incomplete recovery of PtiO2 after definitive clipping. In 2 patients, incomplete recovery of values after definitive clipping led to verification of inappropriate placement and repositioning of the clip. Conclusion: The results suggest that intraoperative monitoring of PtiO2 may be a useful method of detection of changes in brain tissue oxygenation during MCA aneurysm surgery. Postoperative infarction in the territory of MCA developed in cases with an abrupt decrease of PtiO2 and a very low and persistent minimum value, during temporary clipping, and an incomplete recovery after definitive clipping. Verification of clip position should be considered when there is an incomplete recovery or a persistent fall in PtiO2 after definitive clipping.

HM-PAO Spect in Head Trauma

Single Photon Emission Computed Tomography (SPECT) after intravenous administration of Technetium-99m hexamethylpropylene-amine oxime (Tc-99m HM-PAO) makes possible the evaluation of cerebral perfusion. We have been assessing the diagnostic accuracy of SPECT in some groups of head trauma patients: the preliminary results of this study are presented. Fourteen patients have been selected, all of them showing some kind of focal neurological deficit; the Computed Tomography (CT) and Nuclear Magnetic Resonance (NMR) were normal, or showed lesions that could not be responsible for the neurological deficits. In all of the patients Tc-99m HM-PAO SPECT has been performed, showing changes in cerebral perfusion in areas correlated with the abnormalities elicited on clinical examination. These results show that Tc-99m HM-PAO SPECT is a better technique than CT or NMR in demonstrating the organic basis of some neurological deficits observed after head trauma.

Trans-lamina terminalis approach for third ventricle and suprasellar tumours

BACKGROUND The trans-lamina terminalis (TLT) approach to the suprasellar region and third ventricle is complex, with risks of visual and hormonal deficits. However, the postoperative deficits might not be directly related to opening of the lamina terminalis but to the close relationship of tumours with vital neural and vascular structures. The analysis of results using this approach was the objective of this study. MATERIAL AND METHODS The TLT approach was used in 29 patients (18 craniopharyngiomas, 5 astrocytomas, 5 germinomas and 1 ganglioglioma). The extent of tumour removal, mortality and morbidity (especially visual or hormonal deficits) were studied. RESULTS Complete tumour removal was achieved in 15 patients, subtotal extensive removal (more than 90%) in 9 cases and partial removal in 5 cases. Panhypopituitarism developed in 22 patients. Total tumour removal was associated with the development of endocrinological disturbances. There was worsening or the onset of new visual field defects in 4 cases. Postoperative endocrine and visual deficits were in the range generally described regarding surgery for tumours in this region. CONCLUSION The TLT approach allows for extensive removal of third ventricle and suprasellar tumours, without increased risks of visual and hormonal deficits, compared to those described regarding surgery for lesions in this region.

Monitoring of brain tissue oxygenation in surgery of middle cerebral artery incidental aneurysms

Introduction: The management of incidental unruptured aneurysms remains a matter of controversy; middle-sized or large anterior circulation incidental aneurysms, in young or middle age patients, should be considered for treatment. Surgical clipping is an accepted treatment for middle cerebral artery unruptured aneurysms. Ischemic events can occur even in cases of incidental aneurysm surgery. Since regional cerebral blood flow can be compromised due to temporary arterial clipping or to incorrect placement of defi nitive clip, we performed intra-operative monitoring of brain tissue oxygen concentration (PtiO2), to detect changes in brain oxygenation due to reduced blood fl ow, eventually leading to ischemia, during surgery of middle cerebral artery incidental aneurysms. Methods: PtiO2 monitoring was performed during surgery of eight patients harboring incidental MCA aneurysms, using a polarographic microcatheter (Licox, GMS – Kiel, Germany), placed in the temporal lobe on the side of the lesion, from dural opening to dural closure. Results: Basal values varied between 2.3 and 27.3 mmHg; these values are lower than those previously described in the literature as “normal” for uninjured brain or in cases of subarachnoid hemorrhage. In all patients, a significant decrease in PtiO2 was found in every period of temporary clipping of MCA. Post-operative infarction in the territory of middle cerebral artery occurred in one patient and, in that case, there was a persistent minimum value of 0.6 mmHg, without recovery after the placement of the definitive clip. In another patient, an incorrect placement of the definitive clip could be predicted by a decrease in PtiO2 value. Conclusions: PtiO2 monitoring during aneurysm surgery shows brain tissue perfusion in real time and there is a correlation between any episode of reduced blood flow to the affected vascular territory during surgery and a decrease of PtiO2 values. Unexpected low basal values were obtained in “uninjured” brain, with no influence from subarachnoid hemorrhage. The values of risk for brain infarction during temporary arterial occlusion still need further studies, but an incomplete recovery or a persistent fall in PtiO2 values after definitive clipping should be considered as an indication for verification of the position of the clip.

Traumatic interhemispheric subdural haematomas

SummaryAccording to reports in the literature traumatic interhemispheric subdural haematomas (I.S.H.) are supposed to present acutely or subacutely with contralateral monoparesis of a lower extremity or hemiparesis or in bilateral haematomas even with paraparesis, and to need early operative evacuation. In our series of 5 cases none of them followed this “classical” clinical picture, and three of them recovered without operation.We conclude that the indication for operative evacuation depends on the clinical course and that in patients with spontaneously improving symptomatology non-surgical management under close supervision may be the better solution. Also the C.T. finding of open convexity cisterns may be possible indication for conservative management.

Plateau Waves of Intracranial Pressure and Multimodal Brain Monitoring.

The aim of this study was to describe multimodal brain monitoring characteristics during plateau waves of intracranial pressure (ICP) in patients with head injury, using ICM+ software for continuous recording. Plateau waves consist of an abrupt elevation of ICP above 40 mmHg for 5-20 min. This is a prospective observational study of patients with head injury who were admitted to a neurocritical care unit and who developed plateau waves. We analyzed 59 plateau waves that occurred in 8 of 18 patients (44 %). At the top of plateau waves arterial blood pressure remained almost constant, but cerebral perfusion pressure, cerebral blood flow, brain tissue oxygenation, and cerebral oximetry decreased. After plateau waves, patients with a previously better autoregulation status developed hyperemia, demonstrated by an increase in cerebral blood flow and brain oxygenation. Pressure and oxygen cerebrovascular reactivity indexes (pressure reactivity index and ORxshort) increased significantly during the plateau wave as a sign of disruption of autoregulation. Bedside multimodal brain monitoring is important to characterize increases in ICP and give differential diagnoses of plateau waves, as management of this phenomenon differs from that of regular ICP.