gms | German Medical Science

Objective: We report on our preliminary experience in a prospective series of patients concerning feasibility, work flow and image quality using a newly installed multidetector row computed tomography scanner combined with a frameless neuronavigation system in a multidisciplinary operating room suitable for neurosurgery, abdominal and trauma surgery.

Methods: A sliding gantry 24 detector row computed tomography scanner (Somatom Open, Siemens) was installed in a preexisting operating room. The scanner is connected to a frameless infrared-based neuronavigation system (VectorVision Compact, BrainLab). Image data obtained pre- and intraoperatively can be transferred directly from the scanner into the navigation system. This allows an update of the navigation system during surgery by automated image registration based on the position of the gantry. Intraoperative CT-angiography is possible. The patient is positioned on a radiolucent operating table (Jupiter, Trumpf) that fits within the bore of the gantry. During image acquisition, the gantry moves over the patient. This table allows all positions and movements like any normal operating table without any compromise concerning positioning of the patient. For cranial surgery, a carbon radiolucent head clamp is fixed to the table.

Results: Experience with the first 110 patients confirms the feasibility of iCT (57 patients with brain tumors, 1 intracranial aneurysm, 49 patients with spinal lesions, 2 patients with pelvic fractures, 1 shoulder fracture). Following a specific work flow, interruption of surgery for scanning can be limited to 10-12 minutes. Intraoperative imaging changed the course of surgery in 9 of the 110 cases either because control CT showed suboptimal screw position (9/124 screws, with 5 requiring correction) or tumor resection was insufficient (4 cases). Intraoperative CT-angiography was performed in one case so far with good image quality to determine rest flow in the aneurysm. Image quality is excellent in spinal and skull base surgery. For intracranial tumors, care has to be taken to position the head clamp outside the area of examination in order to avoid artefacts.

Conclusions: The system can be installed into a preexisting operating environment without the need for special surgical instruments. It increases the safety for the patient and the surgeon without the need to change existing surgical protocols and work flows. Imaging and updating of the navigation system can be performed at any time during surgery. Multidisciplinary use increases the utilization of the system and thus improves cost-efficiency relation.