Transcranial Doppler for the monitoring of gas embolism in neurosurgical operations in the sitting position

The risk of venous air embolism is significant in neurosurgical procedures performed in the sitting position. Monitoring for venous air embolism, therefore, is crucial and can be approached from several aspects. The most sensitive generally applicable clinical method for the detection of intracardiac gas is based on an application of the Doppler principle. The Authors describe the technique used to adapt a transcranial Doppler (TC 2-64 B, EME, Germany), and a probe designed to record the Doppler signal from intracranial arteries (Transcran FP 2, EME, Germany), as precordial Doppler in order to monitor venous air embolism in neurosurgical procedures performed in the sitting position

Complicanza in corso di embolizzazione pre-operatoria di meningioma intracranico

We report a rare case of meningioma of the parieto-occipital convexity accompanied by hemorrhage in the tumor and in the subdural space that occurred while pre-operative embolization was being applied. The patient, a 48 year old woman, presented sudden headache and, in a few minutes, comatose status and decerebrate rigidity. A quick diagnosis with CT-scan of acute intratumoral and subdural hemorrhage and a rapid intervention on the patient led to complete recovery. The possible reason for the hemorrhage is the sudden change in blood pressure of pathologic small vessels triggered by embolization

Cerebral blood flow velocity and cerebrospinal fluid pressure after single bolus of propofol

The effects of propofol on cerebral blood flow velocity, cerebrospinal fluid pressure, cerebral perfusion pressure and mean arterial pressure were studied during induction in 25 patients scheduled for elective craniotomy. Premedication consisted of only atropine sulphate 0.007 mg/kg (im) 45 min before induction. Measurements were made or derived at time zero and 1, 2, 3, 4 and 5 min after an induction dose of propofol (2.5 mg/kg). Patients were retrospectively stratified into two groups, according to cerebrospinal pressure basal values: (i) lower than 10 mmHg (10 pts) and (ii) higher than 10 mmHg (15 pts). Cerebral blood flow velocity, measured by transcranial Doppler, fell in all the patients, but the reduction was significant at 1, 2, 3 and 4 min only in the group with high CSF pressure, while it never reached the critical value of 10 cm/s. Cerebrospinal fluid pressure and mean arterial pressure decreased in both groups of patients and the fall reached a statistical significance at 1 and 2 min in the group with higher baseline CSF pressure, only at 1 min: a parallel decrease of CPP was recorded, but it was not significant. Thus propofol decreases CSF pressure without hazardous effects on cerebral blood velocity and on cerebral perfusion pressure and seems to be a suitable anaesthetic agent in controlling high cerebrospinal fluid pressure in neuroanaesthesia

Cumulative intracranial tumour volume prognostic assessment: a new predicting score index for patients with brain metastases treated by stereotactic radiosurgery

Brain metastases (BM) represent the most common intracranial malignancy in adults. Limitations of existing prognostic models reduce their predictivity and clinical applicability. The aim of this study is to validate the cumulative intracranial tumour volume prognostic assessment (CITVPA) as a new prognostic score system for patients with BM treated by Stereotactic Radiosurgery (SRS). Between January 2001 and December 2015, 1894 patients underwent Gamma Knife SRS treatment. The CITVPA model was implemented and validated as follows: the CITV cut-offs were identified thanks to a receiver-operating characteristic (ROC) curve analysis; the survival predictive factors were selected through a Cox proportional hazard model; its prognostic power was compared to RPA, SIR and GPA through the Harrel concordance index (HCI). According to the ROC curve analysis, the CITV cut-off values were set at 1.5 and 4.0 cc. Based on the multivariate analysis, the CITVPA model included: age (OR 1.010, 95% CI 1.005–1.015, p < 0.001), KPS (OR 0.960, 95% CI 0.956–0.965, p < 0.001), extracranial metastases (OR 1.287, 95% CI 1.154–1.437, p < 0.001), BM number (OR 1.193, 95% CI 1.047–1.360, p = 0.008), and CITV (OR 1.028, 95% CI 1.020–1.036, p < 0.001). A score between 0 and 1 was attributed to each prognosticator; a global CITVPA score ranging from 0 to 5 was assigned with higher results corresponding to worse outcomes. The CITVPA (HCI = 0.64) exhibited a significantly (p < 0.001) higher prognostic power compared to RPA (HCI = 0.55), SIR (HCI = 0.55) and GPA (HCI = 0.61). The CITVPA represents a reliable prognostic system for patients with BM treated by SRS. However, further prospective and multicentric studies are necessary before its applicability in clinical practice