TY - JOUR

T1 - Minimally invasive mastoidectomy approach using a mouldable surgical targeting system

T2 - A proof of concept

AU - Rau, Thomas S.

AU - Witte, Sina

AU - Uhlenbusch, Lea

AU - Lexow, G. Jakob

AU - Hügl, Silke

AU - Kahrs, Lüder A.

AU - Majdani, Omid

AU - Lenarz, Thomas

N1 - Funding information: Research funding: The presented work was funded by the German Research Association (DFG, Cluster of Excellence (;& ³+HDULQJ DOO´) and by the German Federal Ministry of Education and Research (BMBF, FKZ: 13GW0019E). Responsibility for the contents of this publication lies with the authors. Hannover Medical School holds intellectual property rights on aspects of the technology described herein. Conflict of interest: The authors have no other conflicts of interest to disclose. Iconsent: Informed consent is not applicable. Ethical approval: The use of an anonymised human temporal bone specimen has been approved by the authors' institutional review board under number 3627-2017.

PY - 2018/9/1

Y1 - 2018/9/1

N2 - Hearing restoration using a cochlear implant requires a surgical access to the inner ear. In order to enhance patient safety, reduce trauma, and shorten the patient's time under anaesthesia current research focusses on minimally invasive cochlear implantation surgery by drilling only a single bore hole. This demands a highly accurate surgical assistance device to guide the drill along a predetermined trajectory planned in patient's image data. In this study a recently developed surgical targeting system was evaluated for the first time in a human cadaver trial. After screwing a reference frame on a temporal bone specimen and imaging of both, a trajectory through the facial recess was planned in order to reach the middle ear. Based on this plan a patient specific surgical template including a linear guide for the surgical drill was composed utilizing bone cement. After the hardening of the bone cement the surgical template was mounted on top of the reference frame. The drilling could be performed as previously planned without harming facial nerve and chorda tympani. The deviation of the actual drill hole to the planned trajectory was 0.17 mm at the level of the facial recess. The minimal distance of the drill hole to the facial nerve was 0.59 mm. This proof-of-concept study demonstrates the feasibility of performing the access to the middle ear in a minimally invasive manner using the mouldable surgical targeting system. The presented process allows the patient specific individualization of a drill guide under sterile conditions. This might facilitate its integration into clinical routine.

AB - Hearing restoration using a cochlear implant requires a surgical access to the inner ear. In order to enhance patient safety, reduce trauma, and shorten the patient's time under anaesthesia current research focusses on minimally invasive cochlear implantation surgery by drilling only a single bore hole. This demands a highly accurate surgical assistance device to guide the drill along a predetermined trajectory planned in patient's image data. In this study a recently developed surgical targeting system was evaluated for the first time in a human cadaver trial. After screwing a reference frame on a temporal bone specimen and imaging of both, a trajectory through the facial recess was planned in order to reach the middle ear. Based on this plan a patient specific surgical template including a linear guide for the surgical drill was composed utilizing bone cement. After the hardening of the bone cement the surgical template was mounted on top of the reference frame. The drilling could be performed as previously planned without harming facial nerve and chorda tympani. The deviation of the actual drill hole to the planned trajectory was 0.17 mm at the level of the facial recess. The minimal distance of the drill hole to the facial nerve was 0.59 mm. This proof-of-concept study demonstrates the feasibility of performing the access to the middle ear in a minimally invasive manner using the mouldable surgical targeting system. The presented process allows the patient specific individualization of a drill guide under sterile conditions. This might facilitate its integration into clinical routine.

KW - Cochlear implant

KW - Direct cochlear access

KW - Drill guide

KW - Drilling accuracy

KW - Image-guided surgery

KW - Micro-stereotactic frame

KW - Temporal bone

UR - http://www.scopus.com/inward/record.url?scp=85059760555&partnerID=8YFLogxK

U2 - 10.1515/cdbme-2018-0096

DO - 10.1515/cdbme-2018-0096

M3 - Article

AN - SCOPUS:85059760555

VL - 4

SP - 403

EP - 406

JO - Current Directions in Biomedical Engineering

JF - Current Directions in Biomedical Engineering

IS - 1

ER -