Keeping Cerebrospinal Fluid Leaks and Meningitis at Bay. Defining the optimal exit strategy in pituitary and skull base tumor surgery, PNI authors have published a landmark article in the May 2018 issue of Journal of Neurosurgery. Leading the way in the field of minimally invasive surgery, PNI’s expert team reported on intraoperative repair of skull base defects and prevention of post-operative CSF leaks and meningitis in over 500 patients with pituitary tumors and skull base tumors.