FM2-7 Paediatric robot-assisted DBS surgery: electrode problems and revision techniques

ObjectivesWe review our cases of hardware problems requiring revision surgery and consider the technical aspects of revising the electrodes, including a frameless technique using the Renishaw Guide tubes.DesignRetrospective Review.SubjectsChildren (≤18 years old) who presented with hardware problems following implantation of a DBS for dystonia at King’s College Hospital between May 2005 and April 2018.MethodsInformation was obtained from a prospectively kept database.ResultsOf 166 paediatric patients with DBS, 25 patients had hardware problems, and of these 21 (13%) patients had specifically electrode problems requiring replacement/revision of one or more electrodes. 7 patients had high impedances requiring revision, without obvious lead migration of fracture. 7 patients had lead migration and a further 7 patients had a lead fracture with or without lead migration. 15 patients had original DBS insertion with the Leksell Stereotactic System utilising the Medtronic Stimlock for lead fixation. 6 patients had DBS inserted with the Renishaw Sterotactic Robot and utilised the Renishaw Guide Tubes, in these patients who required lead replacement it was possible to revise the electrode without using stereotactic apparatus. As the guide tubes are implanted in the correct trajectory it is possible to measure the distance required to advance/implant the lead within this to target without the need for full stereotactic reimplantation.ConclusionsElectrode dysfunction is relatively common in children with DBS and a systematic approach is required to identify the cause. When an electrode requires repositioning or replacement, the procedure can be performed in the conventional manner with a stereotactic frame, or freehand without a frame if a Renishaw Guide tube is used at time of first insertion.

The Application of Thermosensitive Gel Nano-Material in Neurosurgery

Thermo-sensitive gel is a kind of macromolecular material with temperature sensibility character. It is liquid under room temperature, and it can be changed to semisolid gel under animal body temperature. Then the medicament in the gel can be released gradually, to gain the sustained-release. We can make use of this character. The makeup of thermo-sensitive gel has a lot of ways, and recently the most in common use is PNIPA. It can be used in tumor cavity’s coating sustained-release chemotherapy after surgical operation, all use methods including：1. Brain glioma re-growing always be happened in tumor local site after neurosurgery operation, and inosculate the chemotherapy medicament into chitosan nanospheres slow-releasing particulates. Then mix into the thermosensitive gel , to be made to spray. During neurosurgical operation, after the surgical treatment for tumor, we spray it in the brain parenchyma cave remain after cutting tumor. When the thermosensitive gel meets the animal temperature, it is changed to membrane-wise glue attached to the tumor cave face. Then after surgical it can absorb moisture nearby, and gel membrane and chitosan nanospheres will release medicament continually. After glioma surgical treatment, the chemotherapy is slowly released partially. 2. Stereotactic surgery injection release interstitial chemotherapy. Under stereotactic apparatus inject gel into the centre of tumor, then the gel changes to colloid from liquid, and then the gel no outflow from tumor. The stereotactic technology offers the effective biopsy, diagnose and accurate and safe administration route for malignant glioma in brain’s depth which cannot be surgical treatment. 3. Embolization chemotherapy in tumor vasculature. Inject the thermosensitive gel into tumor artery, and some parts of gel curdle gradually, then it can embolize tumor capillary network, to interdict the blood to tumor, to control tumor’s growth. In the meantime medicament in gel release gradually, to win the chemotherapy. 4. Cerebral aneurysms and cerebral arteriovenous malformation embolization. Thermosensitive gel makes use of the difference between room temperature and animal heat to make embolism.

Early history of the stereotactic apparatus in neurosurgery

Stereotactic neurosurgery has a rich history, beginning with the first stereotactic frame described by Horsley and Clarke in 1908. It is now widely used for delivery of radiation, surgical targeting of electrodes, and resection to treat tumors, epilepsy, vascular malformations, and pain syndromes. These treatments are now available due to the pioneering efforts of neurosurgeons and scientists in the beginning of the 20th century. Their efforts focused on the development of stereotactic instruments for accurate lesion targeting. In this paper, the authors review the history of the stereotactic apparatus in the early 20th century, with a focus on the fascinating people key to its development.