For such reason, it is particularly important to avoid errors during the navigation process.
Placement of the Ommaya reservoir
Excelim-04 Image-guide System, Fudan Digital Medical Company, Shanghai, China.
Besides the benefits of neuronavigation in tumor localization, tumor resection control, skull base surgery, or in procedures close to functional important structures, several publications pointed out that one of the most valuable applications of frameless neuronavigation was the localization of the craniotomy.
To overcome the limitations of NN based on preoperative imaging, recently it has been proposed to use intraoperative imaging for meningioma surgery: MRI (iMRI), CT (iCT), intraoperative ultrasound (ioUS) and also fluorescent imaging (5-ALA) 12) 13) 14)
Wagner and coworkers 15) showed that in 40% of the cases that had been operated on using intraoperative neuronavigation, the system was only needed to correctly define size and position of the craniotomy. This observation was confirmed in a study of Spivak and colleagues 16).
Integration of metabolism images into multimodal neuronavigation provide not only anatomical, but also metabolic and functional information for frameless stereotaxy, increasing diagnostic yield and avoiding postoperative neurologic deficits 17).
Surgical navigation systems from Medtronic:
StealthStation i7™ – This versatile, integrated surgical navigation system incorporates all the latest navigation technologies into a ceiling mounted boom system to free up space in your OR. Featuring versatile equipment and intra-operative imaging interfaces to optimize your surgical experience.
StealthStation iNav® – This fee-per-use, portable system was designed so every hospital can offer the benefits of surgical navigation technology.
AxiEM Electromagnetic Navigation System – This unique, electromagnetic (EM) tracking technology provides tip-tracking of flexible surgical instruments.
Fusion™ ENT – This innovative EM surgical navigation system is accurate, easy to use, and expandable as needed.
StealthViz™ Planning Station – A powerful 2D/3D surgical planning application that simplifies advanced image viewing, processing, and morphing for navigation.
Frameless neuronavigation based on 3D CTA (3D catheter angiography) registered by only the surface anatomy data contained within the 3D DSA image set. This is an easily applied technique that is beneficial for accurately locating vascular pathological entities and reducing the dissection burden of vascular lesions 18).
While frameless stereotaxis can be used for shunt ventricular catheter placement in patients with smaller ventricles, the ventricular catheter is still commonly placed based on the surface anatomy of the head for patients with larger ventricles. Thus, surgical techniques and guides facilitating accurate and reliable freehand placement of the ventricular catheter still need to be devised.
A retrospective study included a total of 34 patients treated in our Institution between June 2017 and January 2018. Surgical procedures included two groups operated under general anesthesia: microscopic transcranial approach and endoscopic endonasal approach. Preoperative and post-operative navigation accuracy was assessed by two different neurosurgeons.
After our surgical planning navigation protocol was applied, both transcranial and endonasal procedures were successfully performed under navigation guidance in all patients except one. Intraoperative and post-operative complications related to tracker mounted under the hard palate did not occur. In 33 cases a maximal tracking view and optimal navigation accuracy was achieved accounting for a successful rate of 97%.
The position of the patient tracker under the hard palate showed safety, accuracy and feasibility in 97% of our patient. In our case series, it allowed to obtain the main goal to avoid device displacement without invasiveness and postoperative discomfort of the patient 19).