Frameless stereotactic guided neurosurgery: Clinical experience with an infrared based pointer device navigation system

Abstract

An infrared based frameless stereotactic navigation device (Easy Guide Neuro) was investigated for its clinical applicability, registration/application accuracy and limitations in a standard operating room set-up. In a five-month period 40 frameless stereotactic procedures (23 female, 17 male, mean age 46.4, yrs range 10-83) including 36 craniotomies and 4 spinal surgery procedures were performed. Image registration, data transfer and operation planning using skin fixed fiducials (between 5-10, mean 6.6) and CCT in 12 patients/MRI in 28 patients, generally was done the day before surgery. Clinical applicability was proven in all procedures with an additional time for pre-operative imaging and system application in the OR of 50 min mean (35-120 range). A useful registration was achieved in 39/40 patients (97.5%) with a registration accuracy of 3.4 mm (range 1.8-6.7) for brain surgery cases and 14.4 mm (6.8-25) for spine cases. This resulted in intra-operative application accuracy values for brain surgery of 4.2 mm mean (range 1-12). Enhanced registration/application accuracy values over the test period from 4.2/3.8 mm mean (Cases 1-20) up to 3.2/2 mm mean (Cases 21-40) was observed. In spinal surgery an application accuracy of 11.3 mm mean (range 5-20) was found. An intra-operative re-calibration because of system-head drift was necessary in none of the patients, nevertheless, application accuracy degradation due to brain shift was detected in every case. In conclusion, the system allowed a time sufficient accurate frameless intra-operative localisation guidance in cavernoma, meningioma, glioma, and brain metastasis surgery. In spinal surgery, the application accuracy exceeded clinical usefulness due to high registration inaccuracy using skin markers.

High Diagnostic Accuracy of Cytologic Smears of Central Nervous System Tumors

“…Even stereotactically directed navigation systems providing intraoperative radiologic resection guidance cannot solve the problem of defining tumor margins in radiologically well delineated tumor areas, because shift phenomena during resection of large tumor volumes occur. [25][26][27] Since the extent of resection determines survival in…”

Intraoperative computed tomography guided neuronavigation: Concepts, efficiency, and work flow

“…The advantages of the combined application of intraoperative CT and neuronavigation are the realization of neuronavigation without preoperative images and the possibility of recalibration with intraoperative images at any time during surgery. 5,6,8,9,13,16 Based on our results, there is a proven superiority in registration accuracy as compared to navigation using preoperative images. The detection, localization, and resection of residual tumor is another major advantage as is the intraoperative determination of tumor margins to achieve complete resection of intracerebral tumors.…”

“…2,[7][8][9] However, a major problem remains in the form of degradation of accuracy during frameless stereotactic neuronavigation due to brain and/or lesion shift. [12][13][14]16 To solve this problem, an intraoperative CT system was developed that can be connected to a navigation system to overcome the difficulty of working with preoperative images alone. 5,6,10,12 This amazing technical development enables the surgeon to work within a closed intraoperative network based on an intraoperative CT navigation system; the surgeon is a fixed, integrated part of that network.…”

Frameless stereotaxy and anterior cervical surgery

“…Until recently, frameless stereotaxy in spinal surgery has been limited to a few procedures such as placement of pedicle screws 7 or as an adjunct to trans-oral approaches to the craniovertebral junction. 11 However, Roessler et al 12 found few clinical uses for such systems in spinal surgery since skin markers used for registration purposes resulted in excessive inaccuracy. In contrast, Foley and Smith 5 have described applications of interactive image-guided stereotaxis in the spine, and concluded that it was a valuable tool offering an increased margin of safety.…”