Resection of an Intraventricular Metastatic Tumor with Minimally Invasive Port Technique: 2-Dimensional Operative Video.

The use of minimally invasive port technology has been proposed as a safe method to reduce retractor-induced parenchymal injury, particularly for the resection of deep-seated lesions.1-6 A 69-year-old woman with a history of previous colon cancer surgery presented with gait disturbances and progressive headaches. Magnetic resonance imaging revealed a tumor involving the right ventricular atrium that appeared consistent with metastasis. A parieto-occipital craniotomy was performed on the basis of the preoperatively planned surgical trajectory (Video 1). After the dural incision, the arachnoid was opened down to the sulcus under visualization with microscope. Next, the ViewSite Brain Access system tubular retractor (VBAS; Vycor Medical Inc., Boca Raton, Florida, USA) was introduced toward the lesion under navigation guidance. Once the ventricular atrium was entered, the surface of the tumor came into view. It was coagulated and progressively debulked with ultrasonic aspirator. After the mass was adequately decompressed, a plane of dissection between the ependyma and the tumor could be developed with dynamic angulation of the port in order to allow better visualization. Finally, the tumor could be gently rolled away from the choroid plexus and removed. Meticulous hemostasis was achieved, and the tubular retractor was slowly removed. The patient recovered uneventfully without neurologic deficits on follow-up, and the postoperative magnetic resonance imaging evidenced a complete resection of the tumor. The video illustrates technical nuances and demonstrates the feasibility of minimal access port surgery for the resection of intraventricular lesions with low morbidity and mortality using microsurgical techniques. The patient consented to the publication of her image.

Infratentorial Epidural Abscess Secondary to Furunculosis: Case Report and a Review of the Literature.

The authors describe a case of infratentorial epidural abscess caused by community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) in a patient with a recent history of cutaneous furunculosis. This 29-year-old male presented with an occipital headache associated with fever, vomiting, and neck stiffness. Admission magnetic resonance imaging showed a retrocerebellar epidural abscess. Antimicrobial therapy was started, and the patient underwent craniectomy for evacuation of the abscess. Cultures of the surgical specimen were consistent with CA-MRSA. Postoperatively, the patient's condition improved with the resolution of symptoms, and he was discharged home with indication of 6 weeks of antibiotic therapy. Furunculosis is a very rare cause of intracranial epidural abscess but should be considered as a source of infection in an immunocompetent patient.

Mathematical modeling of human glioma growth based on brain topological structures: study of two clinical cases.

Gliomas are the most common primary brain tumors and yet almost incurable due mainly to their great invasion capability. This represents a challenge to present clinical oncology. Here, we introduce a mathematical model aiming to improve tumor spreading capability definition. The model consists in a time dependent reaction-diffusion equation in a three-dimensional spatial domain that distinguishes between different brain topological structures. The model uses a series of digitized images from brain slices covering the whole human brain. The Talairach atlas included in the model describes brain structures at different levels. Also, the inclusion of the Brodmann areas allows prediction of the brain functions affected during tumor evolution and the estimation of correlated symptoms. The model is solved numerically using patient-specific parametrization and finite differences. Simulations consider an initial state with cellular proliferation alone (benign tumor), and an advanced state when infiltration starts (malign tumor). Survival time is estimated on the basis of tumor size and location. The model is used to predict tumor evolution in two clinical cases. In the first case, predictions show that real infiltrative areas are underestimated by current diagnostic imaging. In the second case, tumor spreading predictions were shown to be more accurate than those derived from previous models in the literature. Our results suggest that the inclusion of differential migration in glioma growth models constitutes another step towards a better prediction of tumor infiltration at the moment of surgical or radiosurgical target definition. Also, the addition of physiological/psychological considerations to classical anatomical models will provide a better and integral understanding of the patient disease at the moment of deciding therapeutic options, taking into account not only survival but also life quality.

¿Es factible monitorear la tensión de las meninges? tonometría de aplanación. Ensayo en un modelo teórico / Is monitoring meningeal tension feasible? applanation tonometry. Test on a theorical model

El monitoreo instrumental de la tensión de las meninges -realizado en forma precoz, en el primer agujero de la craneotomía - permitiría una comprobación objetiva, exacta y comparable de las condiciones de operabilidad en la cirugía endocraneana y facilitaría una elección más ajustada de las herramientas con que cuenta el anestesiólogo pra proveer esas condiciones. Buscando el instrumento adecuado para realizar el monitoreo pretendido, investigamos -en un modelo teórico que evoca a la caja craneana y a las meninges- si es factible practicar la tonometría de aplanación en una membrana elástica. La respuesta afirmativa al interrogante planteado en el título nos faculta para analizar, en un trabajo ulterior, qué correlación existe entre la presión endocraneana y la tensión de las meninges en animales y personas, y, posteriormente, apreciar si el monitoreo de la tensión de las meninges (tonometría de la duramadre) es útil para valorar las condiciones de operabilidad en la cirugía endocraneana.

¿Es factible monitorear la tensión de las meninges? tonometría de aplanación. Ensayo en un modelo teórico / Is monitoring meningeal tension feasible? applanation tonometry. Test on a theorical model

El monitoreo instrumental de la tensión de las meninges -realizado en forma precoz, en el primer agujero de la craneotomía - permitiría una comprobación objetiva, exacta y comparable de las condiciones de operabilidad en la cirugía endocraneana y facilitaría una elección más ajustada de las herramientas con que cuenta el anestesiólogo pra proveer esas condiciones. Buscando el instrumento adecuado para realizar el monitoreo pretendido, investigamos -en un modelo teórico que evoca a la caja craneana y a las meninges- si es factible practicar la tonometría de aplanación en una membrana elástica. La respuesta afirmativa al interrogante planteado en el título nos faculta para analizar, en un trabajo ulterior, qué correlación existe entre la presión endocraneana y la tensión de las meninges en animales y personas, y, posteriormente, apreciar si el monitoreo de la tensión de las meninges (tonometría de la duramadre) es útil para valorar las condiciones de operabilidad en la cirugía endocraneana. (AU)