Intraventricular Bone Dust Migration after Endoscopic Third Ventriculostomy: Illustrative Report of 2 Cases.

INTRODUCTION: Autologous bone dust replacement is a commonly used technique to seal a defect created from a burr hole. However, postoperative migration of these bone fragments may occur as an uncommon complication of endoscopic third ventriculostomy (ETV). CASE PRESENTATION: We report 2 cases of intraventricular bone dust migration resulting in acute hydrocephalus from physical obstruction of the stoma and infection. DISCUSSION/CONCLUSION: From our 2 cases as well as other reported cases, the bone dust may have acted as a foreign body and served as a nidus of infection, in addition to causing physical obstruction. A lumbar puncture performed after ETV may have resulted in a suction effect of the bone dust from the burr hole into the ventricular system. Both our cases necessitated urgent surgical intervention to extract the bone fragments and restore CSF flow. Because of its potential complications, we recommend against using autologous bone dust for closure of a burr hole defect after ETV.

Surgery for orbital metastasis from breast carcinoma initially presenting with progressive proptosis.

We present a 45-year-old woman with metastatic breast disease who initially presented with progressive proptosis of her right eye causing limited motility, diplopia and eye pain. MRI done showed an avidly enhancing right sphenoorbital mass causing displacement in the lateral and superior recti muscles with lysis and infiltration of the greater sphenoid wing and lateral orbital wall. The patient underwent surgery resulting in immediate relief of proptosis and resolution of symptoms. Although surgery is not recommended for orbital metastasis as it is not curative, it should be considered as a treatment option as it can provide relief to patients and improve their quality of life.

AVM Compartments: Do they modulate trasnidal pressures? An electrical network analysis.

BACKGROUND: Arteriovenous malformation (AVM) compartments are thought as independently fed, hemodynamically independent components of the AVM nidus. Its possible role in modulating transnidal pressures have not been investigated to our knowledge. OBJECTIVE: To investigate if AVM compartments play a role in modulating transnidal pressures by using electrical models as a method of investigation. MATERIALS AND METHODS: Monocompartmental and multicompartmental AVM models were constructed using electrical circuits- building on Dr. Guglielmi's previous work. Each compartment was fed by two feeding arteries (resistors) and had a shared draining vein with other compartments in the AVM nidus. Each compartment is composed of a series of resistors which represents the pressure gradient along the AVM (arterial, arteriolar, venular, and venous). Pressure (voltage) readings were obtained within these nidal points. RESULTS: The pressure gradient (venous-arterial) is more as there are less AVM compartments in the nidus model. The monocomparmental model had a pressure gradient of 66mmHg (V); while it was 64, 61, and 59 for the 2-, 3-, and 4-compartment models, respectively. In addition, the more the number of compartments, the greater the flow (mA) is in the whole AVM nidus, 33 ml/min for the monocompartmental AVM and 121ml/min for the 4-compartment AVM; though there was greater flow per compartment as there were less compartments, 33ml/min per compartment for the monocompartmental model versus 29ml/min for the 4-compartment model. CONCLUSION: Transnidal pressure gradients may be less the more compartments an AVM has. This electrical model represents an approach that can be used in investigating the hemodynamic contributions of AVM compartments.