Marina Munari

Predictive value of intraoperative 5-aminolevulinic acid–induced fluorescence for detecting bone invasion in meningioma surgery

OBJECT Bone invasion is a major concern in meningioma surgery, since it is predictive of the recurrence of cranial involvement, morbidity, and mortality. Bone invasion has been reported in 20%-68% of studies with histopathologically confirmed data. Unfortunately, radical resection of bone invasion remains challenging. The aim of this study was to assess the role of 5-aminolevulinic acid (5-ALA) fluorescence in guiding the resection of bone-invading meningiomas. To this purpose, the sensitivity, specificity, and positive and negative predictive values of 5-ALA in detecting meningioma bone invasion were evaluated. METHODS Data from 12 patients affected by bone-invading meningiomas (7 with skull base and 5 with convexity meningiomas) who had undergone surgery with the assistance of 5-ALA fluorescence and neuronavigation between July 2012 and March 2013 at the Department of Neurosurgery of Padua were retrospectively analyzed. To evaluate the sensitivity and specificity of 5-ALA fluorescence in detecting meningioma tissue, a pathologist analyzed 98 surgical bone samples under blue light, according to different fluorescence patterns. Magnetic resonance images and CT scans were obtained pre- and postoperatively to determine the extent of bone invasion resection. RESULTS The rate of 5-ALA-induced fluorescence of both tumor and bone invasion was 100%. Based on the pathological examination of bone specimens, 5-ALA presented a sensitivity of 89.06% (95% CI 81.41%-96.71%) and a specificity of 100% in detecting meningioma bone invasion, while the positive and negative predictive values were 100% and 82.93% (95% CI 71.41%-94.45%), respectively. At the postoperative stage, MRI did not detect cases of meningioma bone invasion, whereas CT scans revealed residual hyperostosis in 2 cases. CONCLUSIONS In summary, 5-ALA fluorescence represents a suitable and reliable technique for identifying and removing bone infiltration by meningiomas. However, further studies are needed to prove the clinical consequences of this promising technique in a larger population.

Right parietal cortex and calculation processing: intraoperative functional mapping of multiplication and addition in patients affected by a brain tumor

OBJECT The role of parietal areas in number processing is well known. The significance of intraoperative functional mapping of these areas has been only partially explored, however, and only a few discordant data are available in the surgical literature with regard to the right parietal lobe. The purpose of this study was to evaluate the clinical impact of simple calculation in cortical electrostimulation of right-handed patients affected by a right parietal brain tumor. METHODS Calculation mapping in awake surgery was performed in 3 right-handed patients affected by high-grade gliomas located in the right parietal lobe. Preoperatively, none of the patients presented with calculation deficits. In all 3 cases, after sensorimotor and language mapping, cortical and intraparietal sulcus areas involved in single-digit multiplication and addition calculations were mapped using bipolar electrostimulation. RESULTS In all patients, different sites of the right parietal cortex, mainly in the inferior lobule, were detected as being specifically related to calculation (multiplication or addition). In 2 patients the intraparietal sulcus was functionally specific for multiplication. No functional sites for language were detected. All sites functional for calculation were spared during tumor resection, which was complete in all cases without postoperative neurological deficits. CONCLUSIONS These findings provide intraoperative data in support of an anatomofunctional organization for multiplication and addition within the right parietal area. Furthermore, the study shows the potential clinical relevance of intraoperative mapping of calculation in patients undergoing surgery in the right parietal area. Further and larger studies are needed to confirm these data and assess whether mapped areas are effectively essential for function.

The "squeezing maneuver" in microsurgical clipping of intracranial aneurysms assisted by indocyanine green videoangiography.

BACKGROUND: Indocyanine green videoangiography (ICGV) is becoming routine in intracranial aneurysm surgery to assess intraoperatively both sac obliteration and vessel patency after clipping. However, ICGV-derived data have been reported to be misleading at times. We recently noted that a simple intraoperative maneuver, the “squeezing maneuver,” allows the detection of deceptive ICGV data on aneurysm exclusion and allows potential clip repositioning. The squeezing maneuver is based on a gentle pinch of the dome of a clipped aneurysm when ICGV documents its apparent exclusion. OBJECTIVE: To present the surgical findings and the clinical outcome of this squeezing maneuver. METHODS: Data from 23 consecutive patients affected by intracranial aneurysms who underwent the squeezing maneuver were analyzed retrospectively. The clip was repositioned in all cases when the dyeing of the sac was visualized after the maneuver. RESULTS: In 22% of patients, after an initial ICGV showing the aneurysm exclusion after clipping, the squeezing maneuver caused the prompt dyeing of the sac; in all cases, the clip was consequently repositioned. A calcification/atheroma of the wall/neck was predictive of a positive maneuver (P = .001). The aneurysm exclusion rate at postoperative radiological findings was 100%. CONCLUSION: With the limits of our small series, the squeezing maneuver appears helpful in the intraoperative detection of misleading ICGV data, mostly when dealing with aneurysms with atheromatic and calcified walls. ABBREVIATIONS: DSA, digital subtraction angiography ICG, indocyanine green ICGV, indocyanine green videoangiography

A prospective cohort study on patients treated with anticoagulants for cerebral vein thrombosis

Cerebral vein thrombosis (CVT) is a potentially fatal disorder for which treatment guidelines are scanty. To assess the short‐ and long‐term benefit of anticoagulant therapy, we performed a prospective cohort study on CVT patients.

Intraventricular Hemorrhage Caused by Peripheral Anterior Choroidal Artery Aneurysm Rupture A Case Report

Intraventricular hemorrhage is a severe ictal event secondary to several pathological conditions (anticoagulation therapies, hypertension, post-surgical, traumatic, neoplastic, vascular malformations), leading to blockage of CSF flow and possible hydrocephalus, often justifying surgical intervention. We describe an uncommon source of intraventricular hemorrhage in a 54-year-old woman caused by a peripheral anterior choroidal artery aneurysm rupture.

Transverse sinus thrombosis after posterior fossa surgery for cerebellar tumor treated by endovascular thrombectomy. A case report.

Dural sinus thrombosis is a rare complication after posterior fossa surgery, particularly in cerebellar tumour surgery. The authors describe the case of a young male patient who presented a postoperative neurological deterioration due to transverse sinus thrombosis after surgery for cerebellar medulloblastoma. He was treated by mechanical clot thrombectomy using an endovascular catch system technique without anticoagulation therapy. Final angiographic recanalization was obtained. This kind of endoluminal mechanical revascularization is an efficacious method to treat dural sinus thrombosis during perioperative time but speed in diagnosis is crucial for clinical outcome.