Endo-neuro-sonography: Transendoscopic ultrasound imaging

Objective: The step from micro-neurosurgery toward Endo-Neuro-Surgery meant a step to a minimally invasive technique, but at the same time decreased its safety, which limits its applicability. The goal to further development had therefore been, to make neuro-endoscopy safer. After laboratory work, in a first series of 75 patients with a broad variety of lesions, a sono – catheter for trans-endoscopic imaging was applied for the first time in neurosurgery.

Materials and methods: A trans-endoscopic sono-catheter (Aloka Deutschland GmbH, Düsseldorf/Germany) with a diameter of 1.9mm (6F) and 2.5mm (8F) was used and introduced into the working canal of an endoscope. The image produced by the probe is a 360° scan („brain radar“) displayed on a monitor, on which some parameters can be varied to get best view of different anatomical structures.

Results: In 51 cases intraoperative imaging was the main reason for investigation and in 15 cases neuronavigation was in the focus of interest. In 20 cases of tumor resection control, targeting a visualized remnant was necessary. ENS proved in this small series to make neuroendoscopy safer and easier by online and real-time imaging with high resolution. There are limitations and artifacts which should reveal themselves in laboratory and clinical experience.

Conclusion: Endo-Neuro-Sonography now as it stands, is a technique, which can contribute to the concept of minimally invasive techniques in neurosurgery.

Literature: Resch, K.D.M. Trans-endoscopic Sonography for Neurosurgery. Springer, Stuttgart/NY 10/2005