Application of the Autoguide® Positioning Device for Multiple Stereotactic Tumor Biopsies During a Brain Tumor Resection

Operations involving positioning of needles and catheters are amongst the most common procedures in cranial neurosurgery. One of the most important matters that have to be considered is that, submillimetric (<0.1 mm) precision is essential for the success of these procedures. However, many biopsy needle procedures for obtaining tissue specimens are currently performed with limited accuracy, i.e. using a mechanical arm. This could potentially lead to procedural failure such as inconclusive tissue sampling and even major complications, e.g. cerebral hemorrhage with consecutive neurologic deficits.

Therefore, navigation-guidance was implemented and established over the last two decades. Using preoperatively compiled anatomical patient data from radiological images (Computerized Tomography [CT] or Magnetic Resonance Imaging [MRI] scans) a trajectory from entry to target point can be defined and matched intraoperatively on the patient's head.

In case of stereotactic needle biopsies, inaccuracy is associated with the acquisition of non-diagnostic samples in up to 24% of stereotactic biopsy series or non-representative tumor samples in up to 64% of biopsies. Therefore, serial biopsies could be performed to overcome this drawback - associated with an increased risk of intracranial hemorrhages, which have been reported in 0.3 - 59.8% of the cases and contribute considerably to the reported morbidity of 0-16.1% of this procedure.

The Autoguide® system is a modular guidance system for surgical invasive tools which provides a precise, submillimetric trajectory alignment according to the predefined navigation data.

After the development of this miniaturized robotic guidance system for neurosurgery was successfully finalized, AutoGuide®, a robot for clinical application in neurosurgery, is now commercially available from the Medtronic company.