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1913. Stepwise Development & Commercialization of a Modern Navigable Tubular Access Assembly System Through a Multidisciplinary Startup-Academic Collaboration

Authors: Martina Cartwright; Elizabeth Hagerman, PhD; Brian Dougherty, PhD; Joseph Mark (Scottsdale, AZ)


The concept of using a cylindrical tube for brain retraction was introduced 30 years ago. However, modern imaging & surgery requires a systems approach. Hence, a minimally disruptive access assembly system was invented; it utilizes a navigable tubular retractor that creates a surgical corridor while simultaneously protecting the vasculature & fascicular anatomy via tissue displacement. This system approach lends to functional preservation & improved outcomes.

We describe the steps & timeline involved in creating a navigable tubular access assembly system (NTAAS) from vision to commercialization & address design, regulation, patent & production challenges.


A scientist/inventor, neurosurgeon & academic engineers collaborated to create a NTAAS that follows the natural sulcal folds of the brain to reach tumors/vascular anomalies. Initial prototypes were tested in pigs & human cadavers. The patented NTAAS is made from a light-weight aluminum alloy & plastic. Through live surgical observations & clinician feedback more than 20 individual product characteristics were considered before the NTAAS was ready for commercialization.


Several prototyping & manufacturing runs were required to demonstrate consistent reproducibility. The NTAAS patent application was filed 1/24/2011 & issued 9/26/2017 (Pat .No. 9,770,261). FDA 510K was filed 3/7/2012 & granted 6/5/2012.The patented NTAAS consists of an inner obturator & outer sheath.The obturator tip is configured to gently dilate the sulcal opening from 1.9 to 13.5mm in a single pass while the obturator & sheath glide along the sulcus, limiting abrasive damage. The uniquely designed sheath advances without trapping tissue or disrupting the pia. The distal outer sheath is contoured, mitigating potential parenchyma breech during manipulation. It is ergonomically designed & made of materials compatible with all imaging modalities. The NTAAS has been used in an estimated 5000 patient cases.


Creating & commercializing innovative, clinically relevant devices requires collaboration between scientists, clinicians & engineers.