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Biomedical subjects

W Freysinger

Publications and source records attributed to W Freysinger.

24 records · Page 2Linked to original sources

Computer-assisted surgery in the frontal and maxillary sinus.

We report the intraoperative use of bent probes for 3-dimensional computer-assisted navigation in ENT surgery with the ISG Viewing Wand. Probe calibration is standardized and the new probes comply with the overall application accuracy of the navigation system. The bent probes permit an easy access to the remotest locations of the maxillary and the frontal sinus and are beneficial for application in paranasal sinus surgery. We present our clinical experiences with these probes.

Calibration↗

Three-dimensional image-guided endonasal surgery with a microdebrider.

We report the first intraoperative use of a microdebrider as a stereotactic three-dimensional (3D) navigation instrument in paranasal and frontobasal surgery. The microdebrider uses rotating blades and an integrated suction device for controlled removal of tissue under video-endoscopic view. The ISG Viewing Wand uses the patient's computed tomography/magnetic resonance (CT/MR) data and a 3D reconstruction thereof and a high-precision position-sensitive mechanical arm for intraoperative three-dimensional navigation. We have linked the microdebrider to the Viewing Wand to transform it into a continuously available intraoperative stereotactic localizing device. We discuss the problems related to this extension of the Viewing Wand and demonstrate the practical use in an exemplary polypectomy.

Debridement↗

3D image-guided surgery on the example of the 5,300-year-old Innsbruck Iceman.

Interventional Video Tomography (IVT) is regularly used for computer-assisted 3D navigation in ear-, nose, throat, and head & neck surgery in our clinic. We present the technology and its application to collect biopsies of a 5,300 year old, completely conserved male cadaver, the Iceman. IVT links intraoperative live video with medical imaging data sets, realizing real-time surgical guidance in the live video and/or in the medical images. The IVT data contain the video images and the spatial sensor information; this has a large potential for documentation, training, teaching, and telepresence. IVT allowed us to sample the Iceman's mucosa by the minimally invasive endoscopic approach of the maxillary sinus, the nasal cavity, and the larynx, minimizing tissue damage. Visual inspection of the sinuses and the mucosa revealed the typical mucosa of a fresh cadaver, albeit originating from the stone-age.

Animals↗

Complete sphenoethmoidectomy and computer-assisted surgery.

Many surgical procedures in the field of ENT take place in close proximity to vital structures like the orbit, the skull base, the internal carotid artery etc. In our clinic we have decided to study two different computer-assisted navigation systems to reduce the risk of trauma to these structures during endonasal endoscopic procedures. Such systems should be able to correlate the position of the surgical instrument, ideally in the submillimeter range, to CT- or MR-images. The ARTMA Virtual Patient finds the position of the instrument by permanently measuring magnetic fields. The ISG-system uses a mechanical arm to localize the probe in the patient. Using Computer-Assisted-Surgery (CAS) does not significantly extend the time needed for surgery. We found that it prevents the surgeon from inadvertently injuring structures. Other groups have shown (1) that CAS-systems minimize the risk of complications of surgical procedures in the frontobasis arising from mishaps in the usage of the endoscope or the surgical tool. If properly used, CAS-systems can be a very helpful tool in the hand of an experienced surgeon but will never replace his expertise and knowledge.

Ethmoid Sinus↗