Development of a handpiece and probes for a microsurgical ultrasonic aspirator: Instrumentation and application

OBJECTIVE: To address the several disadvantages of currently available,ultrasonic aspirators used in microsurgery, new instruments were designed for neurosurgical use under a microscope. DESCRIPTION OF INSTRUMENTATION: The weight of the handpiece was reduced to 90 g. Two types of angled probes were constructed. Keyhole-type probes have 93- and 112-mm lengths, a 2.2-mm tip diameter, and 9.5- and 11.2-mm sheath diameters at the most proximal site and produce a tip amplitude of 300 mu m (supplied by 23.5-kHz ultrasonic power). Needle-type probes have 89- and 171-mm lengths, a 1.9-mm tip diameter, and 3.5- and 3.3-mm sheath diameters at the proximal site and produce a tip amplitude of 70 mu m. All of these instruments are compatible with magnetic resonance imaging. METHODS: The newly developed handpiece and probes were used in an experimental model. The 119 mass lesions treated included giant thrombosed aneurysms, various gliomas, vestibular schwannomas, deep-seated meningiomas, clival tumors, and suprasellar tumors. EXPERIENCE AND RESULTS: The handpiece and probes were safely used in regions that are difficult to access, such as the third ventricle and the cerebellopontine angle. It was possible to manipulate the needle-type probe in the suprasellar region through the transsphenoidal route, and the probe Was very efficient for thrombectomy in giant aneurysms. The ultrasonic power of keyhole-type probes was sufficient to remove meningiomas. CONCLUSION: This newly developed neurosurgical handpiece with angled probes has great utility for microscopic dissections, because of its small size and light weight.