A Brief Explanation on Surgical Approaches for Treatment of Different Brain Tumors.

The main goal of brain tumor surgery is to achieve gross total tumor resection without postoperative complications and permanent new deficits. However, when the lesion is located close or within eloquent brain areas, cranial nerves, and/or major brain vessels, it is imperative to balance the extent of resection with the risk of harming the patient, by following a so-called maximal safe resection philosophy. This view implies a shift from an approach-guided attitude, in which few standard surgical approaches are used to treat almost all intracranial tumors, to a pathology-guided one, with surgical approaches actually tailored to the specific tumor that has to be treated with specific dedicated pre- and intraoperative tools and techniques. In this chapter, the basic principles of the most commonly used neurosurgical approaches in brain tumors surgery are presented and discussed along with an overview on all available modern tools able to improve intraoperative visualization, extent of resection, and postoperative clinical outcome.

Diagnosis of Ventriculoperitoneal Shunt Malfunction: A Practical Algorithm.

OBJECTIVE: This study aims to present a practical method to accurately diagnose ventriculoperitoneal shunt (VPS) malfunction and to detect the exact level at which the system has failed to tailor VPS revision at that level only. METHODS: A tertiary referral single-center algorithm for diagnosis of VPS malfunction is proposed. Based on clinical symptoms and confirmed ventricular dilatation on computed tomography, the VPS reservoir is punctured; if no cerebrospinal fluid is obtained, ventricular catheter replacement is recommended. Conversely, if cerebrospinal fluid is obtained, a sample is sent for cultural examination and the macroscopic integrity of the whole system is checked via plain radiography in the angiographic suite. Then, through the injection of iodate contrast medium into the reservoir and selective exclusion of the proximal and distal catheters, the patency and correct VPS functioning are investigated. RESULTS: A total of 102 (56 males) patients (mean age, 41.5 years; range, 1-86 years) underwent a VPS function test from 2012 to 2018: 59 cases of VPS malfunction (57.8%) were diagnosed. Ventricular catheter obstruction/damage/displacement occurred in 12/59 patients (20.3%), valve damage in 11/59 patients (18.6%), distal catheter obstruction/damage/displacement in 17/59 patients (28.8%) and 2-level (valve/proximal catheter or valve/distal catheter) obstruction/damage/displacement in 16/59 patients (27.1%). Subclinical infection was diagnosed in 3 patients (5.1%). VPS revision was performed selectively at the level of failure. CONCLUSIONS: The proposed algorithm is a practical, simple and minimally invasive technique to accurately diagnose VPS malfunction, identifying the exact level of system failure and allowing surgical VPS revision to be tailored, avoiding unnecessary complete system replacement.

Neural network-based identification of patients at high risk for intraoperative cerebrospinal fluid leaks in endoscopic pituitary surgery.

OBJECTIVE: Although rates of postoperative morbidity and mortality have become relatively low in patients undergoing transnasal transsphenoidal surgery (TSS) for pituitary adenoma, cerebrospinal fluid (CSF) fistulas remain a major driver of postoperative morbidity. Persistent CSF fistulas harbor the potential for headache and meningitis. The aim of this study was to investigate whether neural network-based models can reliably identify patients at high risk for intraoperative CSF leakage. METHODS: From a prospective registry, patients who underwent endoscopic TSS for pituitary adenoma were identified. Risk factors for intraoperative CSF leaks were identified using conventional statistical methods. Subsequently, the authors built a prediction model for intraoperative CSF leaks based on deep learning. RESULTS: Intraoperative CSF leaks occurred in 45 (29%) of 154 patients. No risk factors for CSF leaks were identified using conventional statistical methods. The deep neural network-based prediction model classified 88% of patients in the test set correctly, with an area under the curve of 0.84. Sensitivity (83%) and specificity (89%) were high. The positive predictive value was 71%, negative predictive value was 94%, and F1 score was 0.77. High suprasellar Hardy grade, prior surgery, and older age contributed most to the predictions. CONCLUSIONS: The authors trained and internally validated a robust deep neural network-based prediction model that identifies patients at high risk for intraoperative CSF. Machine learning algorithms may predict outcomes and adverse events that were previously nearly unpredictable, thus enabling safer and improved patient care and better patient counseling.

The impact of fluorescein-guided technique in the surgical removal of CNS tumors in a pediatric population: results from a multicentric observational study.

BACKGROUND: Surgery has a fundamental role in central nervous system (CNS) tumors in the pediatric population, as aggressive resection correlates with prognosis. Due to its accumulation in areas with damaged blood brain barrier, sodium fluorescein (SF) could be a valid tool to improve the extent of resection in tumors enhancing at preoperative MRI. This study is aimed to systematically assess the utility of SF in a pediatric population. METHODS: Patient data were collected in two centers, one in Italy and the other in Germany. At the induction of anesthesia, SF was administered intravenously (5 mg/kg). Surgery was performed using a YELLOW560 filter. Fluorescence intensity was graduated as bright, moderate or absent based on surgeon's opinion; furthermore, SF use was judged as "helpful," "not helpful" or "not essential" in tumor removal. RESULTS: Twenty-four patients for 27 surgical procedures were identified. In 21 of 27 (77.8%) procedures fluorescence was reported as bright or moderate, in two of 27 (7.4%) absent and in four of 27 (14.8%) data were unavailable. Intraoperative fluorescence was reported in 21 of 25 (84%) surgeries whose corresponding preoperative MRI had shown contrast enhancement. In 14 of 27 (51.8%) surgical procedures SF was considered "helpful"; in two of 27 (7.4%) not "helpful"; in seven of 27 (25.9%) "not essential." In four of 27 (14.8%) data were unavailable. No adverse effect to SF was registered. CONCLUSIONS: SF could be considered a valid and safe tool to improve visualization of tumors enhancing at preoperative MRI also in pediatric patients. Future prospective studies are needed to confirm these preliminary data.

Use of ICG videoangiography and FLOW 800 analysis to identify the patient-specific venous circulation and predict the effect of venous sacrifice: a retrospective study of 172 patients.

OBJECTIVE The best management of veins encountered during the neurosurgical approach is still a matter of debate. Even if venous sacrifice were to lead to devastating consequences, under certain circumstances, it might prove to be desirable, enlarging the surgical field or increasing the extent of resection in tumor surgery. In this study, the authors present a large series of patients with vascular or oncological entities, in which they used indocyanine green videoangiography (ICG-VA) with FLOW 800 analysis to study the patient-specific venous flow characteristics and the management workflow in cases in which a venous sacrifice was necessary. METHODS Between May 2011 and December 2017, 1972 patients were admitted to the authors' division for tumor and/or neurovascular surgery. They retrospectively reviewed all cases in which ICG-VA and FLOW 800 were used intraoperatively with a specific target in the venous angiographic phase or for the management of venous sacrifice, and whose surgical videos and FLOW 800 analysis were available. RESULTS A total of 296 ICG-VA and FLOW 800 studies were performed intraoperatively. In all cases, the venous structures were clearly identifiable and were described according to the flow direction and speed. The authors therefore defined different patterns of presentation: arterialized veins, thrombosed veins, fast-draining veins with anterograde flow, slow-draining veins with anterograde flow, and slow-draining veins with retrograde flow. In 16 cases we also performed a temporary clipping test to predict the effect of the venous sacrifice by the identification of potential collateral circulation. CONCLUSIONS ICG-VA and FLOW 800 analysis can provide complete and real-time intraoperative information regarding patient-specific venous drainage pattern and can guide the decision-making process regarding venous sacrifice, with a possible impact on reduction of surgical complications.