Creating a Comprehensive Research Platform for Surgical Technique and Operative Outcome in Primary Brain Tumor...

The operative environment poses many challenges to studying the relationship between surgical acts and patient outcomes in intracranial oncological neurosurgery. We sought to develop a framework in which neurosurgical performance and extent of resection could be precisely quantified in a controlled setting.

The stiffness of an alginate hydrogel-based tumor was modified with differing concentrations of the cross-linking agent calcium sulfate until biomechanical properties similar to those of human primary brain tumors measured at resection were achieved. The artificial tumor was subsequently incorporated into an ex-vivo animal brain as a final model. Magnetic resonance imaging enhancement and ultraviolet fluorescence was achieved by incorporating gadolinium and fluorescein solution, respectively. Video recordings from the operative microscope, ceiling cameras, and instrument-mounted fiducial markers within a surgical suite environment captured operative performance.

A total of 24 rheometer measurements were conducted on alginate hydrogels containing 10-, 11-, and 12-mM concentrations of calcium sulfate. Sixty-eight stiffness measurements were conducted on eight patient tumor samples. No differences were found between the alginate and brain tumor stiffness values [Kruskal-Wallis χ²(4) = 9.187; P = 0.057]. Tumor was identified using ultraviolet fluorescence and ultrasonography. The volume and location of the resected white and gray matter and residual tumor could be quantified in 0.003-mm³ increments using a 7T magnetic resonance imaging coil. Ultrasonic aspirator and bipolar electrocautery movement data were successfully transformed into performance metrics.

The developed framework can offer clinicians, learners, and researchers the ability to perform operative rehearsal, teaching, and studies involving brain tumor surgery in a controlled laboratory environment and represents a crucial step in the understanding and training of expertise in neurosurgery.