An interactive, patient-specific virtual surgical planning system for upper airway obstruction treatments

Abstract Surgery is a common mode of treatment for conditions such as septal deviation, turbinate hypertrophy, sleep apnea, and tracheal stenosis resulting from upper airway obstruction. Current diagnosis and the subsequent decision-making of these pathologies primarily rely on the clinical examination and objective measures such as acoustic rhinometry and rhinomanometry that do not correlate well with patient symptoms. The lack of dependable objective measures has resulted in improper procedural prescriptions and less accurate surgical corrections. Therefore providing the surgeons with reliable patient specific objective measures to (a) assist in choosing the appropriate surgical procedure (b) predict and quantify the outcome of a particular or a combination of surgical procedures is essential. In this project, we propose to develop an integrated surgical planning system for upper airway obstruction treatment. We aim to maximize the surgical success rate through informed decision-making achieved using an interactive surgical planning system that can provide quantitative physical metrics based on accurate air flow simulations. This project is a close collaboration between Kitware Inc., Medical College of Wisconsin (MCW) and University of North Carolina (UNC). The co-investigators from MCW and UNC have developed computational fluid dynamics (CFD) simulations in 3D models constructed from CT scans that emulate resting inspiratory airflow in the nasal cavity. They have showed that several biophysical metrics computed from CFD models correlated well with subjective measures of symptoms before and after surgery. In a separate project, a team at Kitware has spearheaded the development of Virtual Pediatric Airway Workbench (VPAW) - a software program that provides a complete pipeline to support surgical planning for treatment for commonly occurring upper airway problems in young children starting with CT scans. In this project, we propose to combine the expertise of teams from MCW, UNC and Kitware to extend VPAW to develop a fully functional, patient-specific, geometrical and simulation-based surgical planning system for upper airway obstruction treatment, using nasal airway obstruction (NAO) surgical treatment as a proof-of-concept. The specific aims of the proposed project are (a) Extend VPAW for surgical planning of other upper airway obstruction treatment and (b) Evaluate the extended VPAW surgical planning system by comparing the CFD metrics resulting from virtual surgery with post-surgical flow simulation metrics in actual patients to assess potential equivalency of the models. The successful completion of this work will result in a proof-of-concept surgical planning system thus paving the way for further developments and clinical studies during Phase II.