Image Guided Surgeryin Otology/Neurotology Panel

ANS – Vancouver September 28, 2013

IGS in Otology/NeurotologyModerator• Darius Kohan, M.D.

o New York University Langone School of Medicineo New York Head and Neck Institute

Panel• Samuel Selesnick, M.D.

o Weill Cornell College of Medicine• Robert Labadie, M.D., Ph.D.

o Vanderbilt University Medical Center• Hinrich Staecker, M.D., Ph.D.

o University of Kansas Medical Center• Daniel Jethanamest, M.D.

o New York University Langone School of Medicine

Accuracy of Image Guided Surgeryin Otology/Neurotology

Darius Kohan, M.D.Chief of Otology/Neurotology

Lenox Hill Hospital/MEETHNew York City

IGS Requirements for Otologic/Neurotologic Use

• Accurate anatomic roadmap (speculate within 1mm)• Distinguish pathology from surrounding

structures• Consistency throughout operative case

IGS in Otology

• Registration– Links preoperative patient

imagery with the physical patient

– It is the greatest source of error in IGS

• Target Registration Error (TRE)– Reflects clinical accuracy and

is an actual measurement of distance between point of surgical interest in the image field and physical field.

Zone of Accuracy

Cadaveric Study Probe Superior SCC

Literature ReviewHow Accurate is IGS in Otology/Neurotology?Year Author Subject Results

2001 Staecker H. Live Surgery 0.9 – 1.5 mm TB accuracy with LandmarX

2005 Coepland B.J. Cadaveric < 1 mm accuracy with BrainLab

2005 Labadie R. Cadaveric TRE – 0.73 +/- 0.25 mm with dental bite plate

2006 Rafferty M. Cadaveric ≤ 0.8 mm spatial resolution with IGS and Cone Beam CT

2009 Caversaccio M. Live Surgery 0.8 – 1.5 mm accuracy in aural atresia and cholesterol granuloma

2009 Hong J. Cadaveric TRE – 1.12 +/- 0.09 mm with hybrid registration and virtual intraoperative CT

2011 Kral F. Cadaveric TRE – Average 2.88 mm at lateral skull base improves to 0.72 +/- 0.28 mm if 0.5 mm HRCT combined intrinsic landmarks and superstructure registration

2012 Matsumoto N. Live Surgery Estimated TRE average 2.4 mm in CI surgery with STAMP registration

Study Published – 2012• 13 patients• 15 procedures/7 years• Limited variables

• Fiducial location close to surgical field on bony prominences or stable anatomy unlikely to shift

• LandmarX system • Same radiologist – HRCT 1 mm cuts performed evening prior

to surgery• Same surgeon

• Target – measured accuracy at 11 landmarks in surgical field

Study Criteria for LandmarX Image Guided Navigational Surgery in Adults Requiring Otologic Surgery

Inclusion Criteria:• Chronic otitis media with extreme disease such as cholesteatoma or neoplastic process with:

• CNS complications• Facial nerve involvement• Otic capsule erosion• Petrous apex disease• IAC compromise• Internal carotid artery involvement• Intracranial extension

• Extensive cholesterol granulomas of the petrous apex requiring surgery• Glomus jugulare tumors Grade C or D• Atresia surgical repair• Cochlear implants with anomalous anatomy• Encephalocele and/or CSF leakExclusion Criteria:• Uncomplicated chronic otitis media• Patient refusal (Lack of consent)• Emergency surgery

Site of Navigational Probe Tip Placement During Surgery

Intraoperative Estimated Accuracy of Navigational Probe Tip Location Versus Surgical Anatomic Landmarks

Source of Registration Errors

• Localization of fiducials• In CT due to image distortion, noise, and resolution• In anatomic space

• Design of fiducial marker• Human error – probe placement• Plasticity at fiducial site – skin shift • Error in tracking system localization of probe

Case OneHistory• 25 YOF with severe left otalgia for 10 days on antibiotics• AS – Cholesteatoma, Tympanomastoidectomy in Ireland at age 8• Age 23 – Meningitis with revision “ear surgery” also in Ireland

• Infection resolved but “lost” hearing

Physical Exam• AS – EEC red, tender, closed• Neuro – left F.N. – 2/6 paresis H/B – patient unaware• Audiogram

• Normal AD• Profound HL – AS – B Tymp.

Case One – Axial CT

Case One – Navigational Study Axial CT

Case One – CT Coronal

Case One – MRI Axial T1

Case One – MRI Axial T1 SE/FAT/SAT

Case One – MRI Coronal T2 with Flair

Case TwoHistory• 61 YOF – Right progressive HL and constant pulsatile tinnitus – 5

years

Physical Exam• AD – anterior inferior erythematous pulsatile mass deep to

intact TM• Neuro – intact

MRA/V• AD – expansile hyperintense mass at petrous apex against IAC

and jugular bulb

Case Two

Case Two – Axial CTCyst Abuts Carotid Artery

Case Two – Axial CT

LandmarX Probe Lateral Surface of Cyst

LandmarX Trajectory into Cholesterol Cyst

Case ThreeHistory• 43YOF – Right progressive HL and nonpulsatile fluctuating

tinnitus – 3 years

Physical Exam• AU – WNL• Neuro – intact

Case Three

Case Three – Axial CT

Case Three – Coronal CT

Case Three – Coronal CT

Case Three - MRI

LandmarX Probe on Facial Nerve – Cholesterol Cyst

LandmarX Probe in Center of Cholesterol Cyst

Case Four - Atresia

28 year old male born with right aural atresia, maximum CHL, presents with a one year history of progressive right facial paresis

Case Four - Atresia

Case Four – Axial MRI T1 w/o C

Case Four – Axial MRI T1 w/o C

Case Four – Axial MRI T1 with C

Case Four – Axial MRI T1 with C

Case Four – Coronal MRI T1 with C

Why IGS in Otology/Neurotology?

IGS…• Provides real-time data localizing extent of pathology relative to

a fluid surgical landscape• Prior procedures and pathology may have distorted or destroyed

anatomic landmarks • May help in complex otologic surgery• May be a good teaching tool in academic programs• Has potential to improve surgical outcome and patient safety• Robotic surgery?