3. Subcortical stimulation with ultrasound aspiration TIP

Abstract

During intrinsic tumour removal, subcortical electrical stimulation is increasingly used for detection of possible function of the tissue to be removed, frequently with ultrasonic aspiration. Usually a stimulation probe is introduced in the operative cavity for mono – or bipolar electrical stimulation of the area intented to be resected. This includes a supplementary loss of time, and a possible inaccuracy in the localisation of the involved area. To avoid these drawbacks, the tool used for tumour removal can be implemented for simultaneous monopolar stimulation, between or even during tumour resection. The tip of some ultrasound aspiration devices can be implemented for monopolar current transmission, e.g. for coagulation in liver surgery; this circuitry can be used for monopolar subcortical stimulation at the very tip of the device, where tissue is cavitated and aspirated. This method was applied in over 500 patients during tumour resection with cortical and subcortical stimulation, mostly with awake language and motor monitoring. The subcortical stimulation with US aspiration probe tip improved the accuracy of the procedure, with reduction of operative time. It reveals to be a safe, fast and inexpensive tool in resection of lesions where subcortical stimulation is important. Simultaneous subcortical stimulation and ultrasonic aspiration with the same device improves the quality and speed of intrinsic intracranial lesion resection.