The Experts below are selected from a list of 2814 Experts worldwide ranked by ideXlab platform
Reto Bale - One of the best experts on this subject based on the ideXlab platform.
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neuroendoscopy based on computer assisted adjustment of the endoscope Holder in the laboratory
Minimally Invasive Neurosurgery, 2003Co-Authors: Johannes Burtscher, Reto Bale, Reinhart A Sweeney, W Eisner, K TwerdyAbstract:Objective: We present our initial clinical experience with a novel technique of frameless stereotactic neuroendoscopy using a neuronavigation system, a specially designed aiming device (endoscope Holder/targeting device) combined with a vacuum-mouthpiece based Head Holder. Due to the reproducibility of patient immobilization in the fixation system, the endoscope Holder can be adjusted in the laboratory in the absence of the patient. Methods: An individual vacuum-mouthpiece was fabricated. The patients were scanned with an external reference frame attached to this mouthpiece and the images were transferred to the neuronavigation system. Determination of the path, mouthpiece-based registration and adjustment of the targeting device were performed the day before surgery in the absence of the patient. In the OR the patient was repositioned and the endoscope was introduced through the preadjusted aiming device to the precalculated depth. Results: The novel technique was successfully used for frameless endoscopic navigation in five patients. Three endoscopic third ventriculostomies in adults, one endoscopic septostomy due to unilateral hydrocephalus in an adult female patient and one endoscopic ventriculo-cysto cisternostomy in a 20-month-old girl with a suprasellar arachnoid cyst, were performed with excellent clinical results and without technical complications. Conclusion: Our initial experience indicates that frameless stereotaxy, in combination with a relocatable Head Holder and a special targeting device, allows for precise and preplanned advancement of the neuroendoscope, reducing or even eliminating intraoperative registration and endoscope trajectory adjustments, thus substantially reducing OR time. Due to the non-invasive but rigid immobilization method, neuronavigation can also be performed in children under 2 years of age.
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Minimally Invasive Head Holder to Improve the Performance of Frameless Stereotactic Surgery
Laryngoscope, 1997Co-Authors: Reto Bale, Michael Vogele, Wolfgang Freysinger, Andreas R. Gunkel, Klaus Bumm, Alex Martin, Walter F. ThumfartAbstract:Frameless stereotactic procedures crucially depend on the firmness of immobilization. Once registered, shifting of the patient leads to inaccuracy, and the patient registration has to be realigned. To overcome the drawbacks of conventional invasive fixation for neurosurgery and the widely accepted fixation with surgical tape in ENT, the Vogele-Bale-Hohner (VBH) Head Holder has been developed. It permits rigid, noninvasive fixation of the Head by using an individualized dental cast attached to the upper jaw by vacuum. Oral intubation is uncomplicated. In addition, a special registration device providing well defined reference points can be mounted to the mouthpiece. We report the first promising clinical applications of this device.
Arlan Mintz - One of the best experts on this subject based on the ideXlab platform.
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image guided frameless stereotactic needle biopsy in awake patients without the use of rigid Head fixation
Journal of Neurosurgery, 2011Co-Authors: Devin V Amin, Karl Lozanne, Phillip V Parry, Johnathan A Engh, Kathleen Seelman, Arlan MintzAbstract:Object Image-guided frameless stereotactic techniques provide an alternative to traditional Head-frame fixation in the performance of fine-needle biopsies. However, these techniques still require rigid Head fixation, usually in the form of a Head Holder. The authors report on a series of fine-needle biopsies and brain abscess aspirations in which a frameless technique was used with a patient's Head supported on a horseshoe HeadHolder. To validate this technique, they performed an in vitro accuracy study. Methods Forty-eight patients underwent fine-needle biopsy of intracranial lesions that ranged in size from 0.9 to more than 107.7 ml; a fiducial-less, frameless, image-guided technique was used without rigid Head fixation. In 1 of the 48 patients a cerebral abscess was drained. The accuracy study was performed with a skull phantom that was imaged with a CT scanner and tracked with a registration mask containing light-emitting diodes. The objective was a skin fiducial marker with a 4-mm circular target to ...
Jurgen Beck - One of the best experts on this subject based on the ideXlab platform.
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the silent loss of neuronavigation accuracy a systematic retrospective analysis of factors influencing the mismatch of frameless stereotactic systems in cranial neurosurgery
Neurosurgery, 2013Co-Authors: Lennart Stieglitz, R H Andres, Annkathrin Krahenbuhl, Philippe Schucht, Jens Fichtner, Andreas Raabe, Jurgen BeckAbstract:BACKGROUND Neuronavigation has become an intrinsic part of preoperative surgical planning and surgical procedures. However, many surgeons have the impression that accuracy decreases during surgery. OBJECTIVE To quantify the decrease of neuronavigation accuracy and identify possible origins, we performed a retrospective quality-control study. METHODS Between April and July 2011, a neuronavigation system was used in conjunction with a specially prepared Head Holder in 55 consecutive patients. Two different neuronavigation systems were investigated separately. Coregistration was performed with laser-surface matching, paired-point matching using skin fiducials, anatomic landmarks, or bone screws. The initial target registration error (TRE1) was measured using the nasion as the anatomic landmark. Then, after draping and during surgery, the accuracy was checked at predefined procedural landmark steps (Mayfield measurement point and bone measurement point), and deviations were recorded. RESULTS After initial coregistration, the mean (SD) TRE1 was 2.9 (3.3) mm. The TRE1 was significantly dependent on patient positioning, lesion localization, type of neuroimaging, and coregistration method. The following procedures decreased neuronavigation accuracy: attachment of surgical drapes (DTRE2 = 2.7 [1.7] mm), skin retractor attachment (DTRE3 = 1.2 [1.0] mm), craniotomy (DTRE3 = 1.0 [1.4] mm), and Halo ring installation (DTRE3 = 0.5 [0.5] mm). Surgery duration was a significant factor also; the overall DTRE was 1.3 [1.5] mm after 30 minutes and increased to 4.4 [1.8] mm after 5.5 hours of surgery. CONCLUSION After registration, there is an ongoing loss of neuronavigation accuracy. The major factors were draping, attachment of skin retractors, and duration of surgery. Surgeons should be aware of this silent loss of accuracy when using neuronavigation.
Walter F. Thumfart - One of the best experts on this subject based on the ideXlab platform.
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Minimally Invasive Head Holder to Improve the Performance of Frameless Stereotactic Surgery
Laryngoscope, 1997Co-Authors: Reto Bale, Michael Vogele, Wolfgang Freysinger, Andreas R. Gunkel, Klaus Bumm, Alex Martin, Walter F. ThumfartAbstract:Frameless stereotactic procedures crucially depend on the firmness of immobilization. Once registered, shifting of the patient leads to inaccuracy, and the patient registration has to be realigned. To overcome the drawbacks of conventional invasive fixation for neurosurgery and the widely accepted fixation with surgical tape in ENT, the Vogele-Bale-Hohner (VBH) Head Holder has been developed. It permits rigid, noninvasive fixation of the Head by using an individualized dental cast attached to the upper jaw by vacuum. Oral intubation is uncomplicated. In addition, a special registration device providing well defined reference points can be mounted to the mouthpiece. We report the first promising clinical applications of this device.
Eiji Kohmura - One of the best experts on this subject based on the ideXlab platform.
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diagnostic yield and morbidity by neuronavigation guided frameless stereotactic biopsy using magnetic resonance imaging and by frame based computed tomography guided stereotactic biopsy
Surgical Neurology International, 2014Co-Authors: Masamitsu Nishihara, Naoya Takeda, Tomoaki Harada, Keiji Kidoguchi, Shoutarou Tatsumi, Kazuhiro Tanaka, Takashi Sasayama, Eiji KohmuraAbstract:Background We compared the diagnostic yield and morbidity by frame-based computed tomography-guided stereotactic biopsy (CTSTB) with Brown-Roberts-Wells (BRW) unit and by neuronavigation-guided frameless stereotactic biopsy (NSTB) using magnetic resonance imaging (MRI). Methods The subjects' age range was 15-83 years. CTSTB with BRW unit was performed for 59 tumors (58 cases, 1988-2007). NSTB was performed for 38 tumors (35 cases, 2007-2013) with the needle sheath attached to the Head Holder. By NSTB, target locations of sampling points and trajectories were confirmed by using MRI. Diffusion tensor imaging-based fiber tractography was used to achieve safe trajectories. STB by using BRW did not visualize the trajectory virtually; however, the planning images for NSTB were able to show the trajectory virtually before the procedure. Results Histological diagnoses were established for 93 tumors at the first biopsy. The diagnostic yield was 94.9% by CTSTB and 97.4% by NSTB (P = 0.944). The morbidity rate was 5.1% by CTSTB and 0% by NSTB (P = 0.417). The absolute risk reduction was 23.1% by NSTB when the targets were basal ganglia (putamen, globus pallidus) or thalamus. In the cases of glioma for which the targets were basal ganglia (putamen, globus pallidus) or thalamus, the absolute risk reduction by NSTB was 30%. Conclusions There was no significant difference between CTSTB and NSTB concerning the diagnostic yield and morbidity. However, when the target is the basal ganglia (putamen, globus pallidus) or thalamus and glioma is suspected, NSTB by using MRI with virtual trajectory is preferable to CTSTB concerning morbidity.
