Fiber-Optic Intracranial Pressure Monitoring System Using Wi-Fi-An In Vivo Study.

BACKGROUND: Continuous invasive monitoring of intracranial pressure (ICP) is essential in neurocritical care for surveillance and management of raised ICP. Fluid-based systems and strain gauge microsensors remain the current standard. In the past few decades, several studies with wireless monitoring were developed aiming to reduce invasiveness and complications. OBJECTIVE: To describe a novel Wi-Fi fiber-optic device for continuous ICP monitoring using smartphone in a swine model. METHODS: Two ICP sensors (wireless prototype and wire-based reference) were implanted in the cerebral parenchyma of a swine model for a total of 120 minutes of continuous monitoring. Every 5 minutes, jugular veins compression was performed to evaluate ICP changes. The experimentation was divided in 3 phases for comparison and analysis. RESULTS: Phase 1 showed agreement in ICP changes for both sensors during jugular compression and releasing, with a positive and strong Spearman correlation (r = 0.829, P < .001). Phase 2 started after inversion of the sensors in the burr holes; there was a positive and moderately weak Spearman correlation (r = 0.262, P < .001). For phase 3, the sensors were returned to the first burr holes; the prototype behaved similarly to the reference sensor, presenting a positive and moderately strong Spearman correlation (r = 0.669, P < .001). CONCLUSION: A Wi-Fi ICP monitoring system was demonstrated in a comprehensive and feasible way. It was possible to observe, using smartphone, an adequate correlation regarding ICP variations. Further adaptations are already being developed.

Cranioplasty with three-dimensional customised mould for polymethylmethacrylate implant: a series of 16 consecutive patients with cost-effectiveness consideration.

BACKGROUND: Different methods of cranioplasty for the reconstruction of bony skull defects exist. In the absence of the autologous bone flap, a customised manufactured implant may be the optimal choice, but this implant has several limitations regarding its technical standardisation and better cost-effectiveness. METHODS: This study presents a series of 16 consecutive patients who had undergone cranioplasty with customised three-dimensional (3D) template moulds for polymethylmethacrylate (PMMA) implants manufactured after 3D modelling on a specific workstation. The virtual images were transformed into a two-piece physical model using a 3D printer for the biomaterials. PMMA implant was produced intraoperatively with the custom mould. Cosmetic results were analysed by comparing pre- and postoperative 3D computed tomography (CT) images and asking if the patient was satisfied with the result. RESULTS: The average total time for planning and production of customised mould was 10 days. The 16 patients were satisfied with the result, and CT images presented harmonious symmetry when comparing pre- and postoperative scans. Cases of postoperative infection, bleeding, or reoperation in this series were not observed. CONCLUSION: Cranioplasty with high-technology customised 3D moulds for PMMA implants can allow for an aesthetic reconstruction with a fast and cost-effective manufacturing process and possibly with low complication rates.

5-aminolevulinic Acid and Surgical Margin Analysis in Calvarial Metastasis with Pericranium or Dural Extension: Technical Note

Metastasis to the calvarium with direct pericranium or dural infiltration may be treated with radical surgical removal in selected cases. We describe microsurgical resection of calvarial metastases with fluorescence-guided technique using 5-aminolevulinic acid (5-ALA) in two female patients with breast cancer. Fluorescence findings were positive in both cases. Margins in the scalp and dural layer were 5-ALA negative at the end of surgical removal. Intraoperative pathology was performed in all cases to confirm if oncological limits were free of disease. One case was 5-ALA positive in the outer layer of the dura-mater and another in the pericranium. At the end of the removal in both cases, the surgicalmargins were 5-ALA fluorescence-free. Intraoperative pathology confirmed oncological limits of the resection. 5-aminolevulinic acid fluorescence-guided surgery for calvarial metastases with pericranium and/or dural extension seems to be a safe and reliable method to aid the surgical margins for complete removal, possibly delaying or avoiding adjuvant irradiation for progression control.