Lateral Ventricle to Sylvian Fissure Shunt for Obstructive Hydrocephalus: First Report

Cerebrospinal fluid (CSF) pathway studies have revealed that the CSF secreted from the choroid plexus of the ventricles after egressing from the fourth ventricle reaches the basal suprasellar cistern and ultimately the sylvian cisterns. From the sylvian cistern, the CSF travels over the cerebral convexity subarachnoid space to reach the superior sagittal sinus and enters the bloodstream. Diverting CSF from the lateral ventricle with a shunt catheter to the sylvian cistern can be an option to treat obstructive hydrocephalus. An adult patient with posttraumatic hydrocephalus with contraindications to ventriculoperitoneal and ventriculoatrial shunt placement underwent this procedure of diverting CSF from the lateral ventricle to the sylvian cistern successfully, and he had immediate relief of symptoms of raised intracranial pressure. Although preliminary results seem logical and promising, more cases and longer follow-up is required to consider this shunt operation an option in the treatment of obstructive hydrocephalus.

Development of an Instrumented Surgical Setup for Quantifying Displacement and Force in Surgical Dissection

Knowledge of positional and force properties of surgical dissection in neurosurgery is essential in developing simulation platforms for neurosurgical training such that realistic motion and perception can be conveyed to the trainee during practice. Most proposed models in literature utilize computational techniques to formulate required parameters. However, these models are not realistic enough compared to data obtained from experiments on real brain. Therefore, developing a setup to measure the position, orientation, and interaction forces will help researchers formulate realistic parameters. This paper presents the development of such a setup for quantification of displacements and tool-tissue interaction forces during performance of microsurgical tasks. A bipolar forceps is equipped with a set of force sensing elements to measure the tool-tissue interaction force components. The position and orientation of the forceps tips are measured by attaching a tracker to the bipolar forceps. To show proof-of-concept, an experienced surgeon and one assistant surgeon performed 35 neurosurgical tasks (320 trials) on a cadaver brain (previously-frozen) using the instrumented setup. Positional and force data of the bipolar forceps were recorded during surgical dissection of different brain structures. This paper reports results collected from two microsurgical tasks over 40 trials: dissection of sylvian cistern arachnoid (SCA) and dissection of middle cerebral artery (MCA). Results showed that the mean values of interaction forces during dissection of MCA were smaller than dissecting SCA. The maximum forces observed were 1.94 N and 1.75 N for SCA and MCA, respectively. The application of quantifying such parameters using the developed setup will be in training neurosurgery residents using surgical simulators in which the knowledge of brain tissue parameters is required to formulate the tissue model.