I. Todorov, T. Eftimov, I. Hadzhiangelov, V. Nakov, P. Simeonov, E. Stavrev, C. Ninov, K. Romanski, Al. Petkov
Department of Neurosurgery, Military Medical Academy – Sofia, Bulgaria

Objective: For more than two decades the neuronavigation was successfully used in the neurosurgery. Some shortcomings of the method have evoked the need of an appropriate intraoperative imaging to compensate for the registration and shifting bias and the intraoperative ultrasound is found to be a good option. To analyze the results of the usage of intraoperative ultrasound combined with neuronavigation in different fields of neurosurgery.

Material and Methods: Between the years 2008 and 2013, 240 surgeries under ultrasound/navigation guidance were performed in the Department of Neurosurgery of the MMA – Sofia. Patients were at an average age of 54±14.26 years, harboring oncologic (91.3%), vascular (6.7%), inflammatory (1.3%) and congenital (0.8%) diseases. Integrated ultrasound navigation system (Sonowand Invite) was used intraoperatively in different modes: ultrasound only – in 46cases; 3D ultrasound registration – in 72 cases; “classic” neuronavigation (based on preoperative images) – in 15cases; and ultrasound-based navigation – in the rest 107 (45%) cases.

The Power Doppler and Color Doppler capabilities of the ultrasound scanner were used in 64 of the exams, mostly for vascular disorders and highly vascularised tumors.

Results: Metastases (90 pts) and glial tumors (90 pts) prevailed among the oncologic cases, followed by meningiomas (24 pts). In 152 surgeries (69.4%) a total resection was achieved and in 6 cases (2.7%) with low-grade astrocytoma – a supratotal resection with perfect functional outcome. Among the vascular diseases, 6 out of 8 aneurysms were successfully clipped and one was “trapped”. All of the AVMs (2 pts) were totally excised. The complication rates were comparatively low with mostly transient neurologic worsening (26%) and only 9% surgical complications. The overall mortality for the series was 5%.

Discussion: The intraoperative ultrasound, combined with neuronavigation, appears to be a useful tool in the hands of the experienced surgeon in different neurosurgical fields when properly used and with caution on indications.

Key words: complications, neurosurgery, surgical results, ultrasound navigation.