Report of a New Passive, Optical Surgical Navigation System for Endoscopic Sinus Surgery Martin J. Citardi, M.D. Saint Louis University Department of Otolaryngology
Computer-Aided Sinus Surgery Anatomic complexity Limitations of endoscopic visualization Surgical navigation systems
SAVANT New CAS platform Cbyon (Palo Alto, CA) Optical tracking system Windows NT platform Report of initial FDA trial
Methods Prospective trial (FDA protocol) 1 mm axial CT transferred to workstation via network Visual estimates of registration accuracy Surgeon’s questionnaires
SAVANT Pre-release software version ( ) Headset reference frame Semiautomatic registration Passive (wireless) instruments
Semiautomatic Registration Headset at time of CT scan and OR Registration to points on headset
SAVANT Instrumentation
Results 17 patients enrolled Indication: chronic rhinosinusitis Failure to achieve acceptable registration in 1 instance Surgery canceled in 1 instance (asthma exacerbation) 15 patients completed protocol
Results Registration accuracy estimates at 4 points in surgical volume Distribution of estimates: 0-2 mm.38 (63.3%) 2-4 mm.14 (23.3%) 4-6 mm.3 (5.0%) >6 mm.5 (8.3%)
Subjective Evaluation Relatively easy set-up, especially for a developmental system Good user interface Excellent monitor Excellent technical support
Representative Images
Headset Issues Modified Anatomark headset (designed for co- registration of MR/CT scans) DRF design Ear piece calibration Fully automatic registration anticipated
Advantages Even semiautomatic registration rapid Passive (wireless) tracking Excellent user interface Automatic registration in development
Disadvantages Headset design issues Semiautomatic registration Note: Technical solutions are on the horizon…
Summary Preliminary report of a new CAS system for sinus surgery Promising technological platform System limitations identified; technical solutions in early implementation phase Additional reports forthcoming…