Safe brain surgery

The Institute of Neurosciences has developed a series of integrated procedures to ensure maximum safety in its brain surgery procedures.

- Before the procedure. A proper planning for brain surgery enables the integration of an increasing amount of anatomical, physiological, and functional information that can be incorporated into a stereoscopic 3D model of the skull and brain. This model can be viewed in virtual/augmented reality and in 2D, and can also be printed on 3D printers. We can segment a tumour or brain resection, simulate a cranial opening, take rectilinear and curvilinear measurements, integrate physiological information about the tumour or brain (PETs - positron emission tomography activity maps -, SPECT and SISCOM (especially in epilepsy surgery), MR perfusion sequences), functional (functional MRI maps of tasks and resting state, and TMS), as well as morphological connectivity sequences (HARDI tractography).

Ultimately, the goal is to obtain optimal safety margins and surgical approaches for the removal of tumours and other brain lesions or abnormalities. For example, locations of language and sensory-motor areas, as well as their fibres and connectivity tracts around or within the planned resection.

- During the procedure. Advanced neuronavigation allows all of the aforementioned planning elements to be integrated, co-registered in the operating theatre with each patient's actual anatomy, and visualised during surgery. Anatomical elements in the surgical field often shift, which in extreme cases can be up to 2 cm, referred to as cerebral ‘shift’. To correct this, intraoperative ultrasound is used, which can be co-registered with the neuronavigator image. To further minimise the risk to functions such as motor skills or sensitivity, neurophysiological monitoring systems are used with the patient under general anaesthesia. To minimise the impact on language function, the patient undergoes surgery while awake, which allows this function to be mapped in the cerebral cortex and also subcortically during removal in the white matter, while a neuropsychologist with highly specific training monitors this function. Using these techniques, Dr Conesa has operated on more than 700 patients since 1989, with a morbidity rate of less than 4% for these procedures.

In addition to these functional safety features, the Institute of Neurosciences has a complete Kinevo (Zeiss) robotic platform, which also enables an additional Quevo support endoscope with integrated vision directly on the surgical microscope viewer or the built-in screens. In addition, brain tumours can be marked with red fluorescence using 5-ALA (Gliolan®) or yellow fluorescence using fluorescein. The cerebral vascular network can also be viewed using fluorescence. This 4K platform also allows these surgeries to be performed in exoscopic mode and surgical recordings of the highest quality to be made.

The laser brain ablation system (Visualase by Medtronic) has ushered in a paradigm shift in brain surgery. Access to the target lesion is achieved through a minimal cranial opening of 1.6 mm. The precision in positioning the laser probe is optimal with the innovative Leksell Vantage stereotactic system, which is compatible with MRI as it is made of carbon. The functional safety and efficacy of ablation on the target tissue is observed online in the MRI room by superimposing the synchronous recording of highly detailed morphological sequences with high-precision sequences in the recording of temperature changes (thermographic).

Finally, the possibility of performing surgeries in the hybrid operating theatre allows for mixed endovascular and microsurgical procedures to be carried out on cerebral aneurysms, cerebral arteriovenous malformations (AVMs) and arteriovenous fistulas. It also allows verification of the microsurgical closure of the operated aneurysm and the excised AVM or interrupted AVF.