Microbot Medical Bologna presention.
O69 Biocompatibility of the novel microbot medical SCS shunt catheter
James P McAllister II1, Leandro Castaneyra-Ruiz1, Albert M Isaacs1, Michael Talcott1,2, Simon Sharon3, Or Samoocha3, Eran Cohen3, Ian Boader3, Carolyn A Harris4, Hezi Himelfarb3
1Department of Neurosurgery, Division of Pediatric Neurosurgery, Washington University School of Medicine, St. Louis, United Sates; 2Division of Comparative Medicine, Washington University School of Medicine, St. Louis, United Sates; 3Microbot Medical Ltd, Caesarea, Israel; 4Department of Chemical Engineering, Wayne State University, Detroit, United Sates
Correspondence: James P McAllister II
Fluids and Barriers of the CNS 2018, 15(Suppl 2):O68
Introduction: Since occlusion of ventriculoperitoneal shunt (VPS) catheters continues to be a major cause of treatment failure in hydrocephalus patients, Microbot Medical, Inc. has designed the self-cleaning ventricular catheter (SCS) to resist catheter obstruction. Following promising in vitro and ex situ studies, preclinical evaluations of the SCS are needed, with an initial focus on biocompatibility.
Methods: Hydrocephalus was induced in 30-day old piglets by percutaneous intracisternal injection of 25% kaolin. After ventriculomegaly had developed for 3–44 days, standard VPS (n?=?1) and SCS (n?=?4) catheters were implanted using routine surgical procedures. The Microbot activation coil was placed into a subcutaneous pocket behind the left ear and distal catheters were tunneled subcutaneously and inserted into the peritoneal cavity. Animals were monitored for neurological deficits, ventriculomegaly, and sacrificed at 5–49 days post-shunt (median 15d). Fixed tissue blocks containing the catheter path were processed for histopathology and immunohistochemistry.
Results: Preliminary observations indicate that unactivated Microbot catheters exhibit the same neural tissue reaction as the standard commercial catheter in current clinical practice, although ventriculomegaly increased somewhat after shunting (ventricular volume 2774 mm3 vs 4051 mm3). Both types of catheters were ensheathed by a very thin capsule of collagenous and astrocytic tissue as they passed through brain tissue or contacted the ependyma. Adjacent white matter exhibited a mild inflammatory reaction that extended only 0.2–1.0 mm beyond the surface of the catheter.
Conclusions: The inflammatory reaction to the Microbot catheter appeared to be no different than the reaction to the standard catheter.
O70 Development of a piglet model of hydrocephalus for endoscopic third ventriculostomy
James P. McAllister II1, Michael Talcott2, Albert M. Isaacs1, Leandro Castaneyra-Ruiz1, Alexis Hartman1, David D. Limbrick Jr1
1Department of Neurosurgery, Division of Pediatric Neurosurgery, Washington University School of Medicine, St. Louis, Missouri, United States; 2Division of Comparative Medicine, Washington University School of Medicine, St. Louis, Missouri, United States
Correspondence: James P. McAllister II
Fluids and Barriers of the CNS 2018, 15(Suppl 2):O69
Introduction: Large, clinically-relevant animal models of hydrocephalus in which neurosurgical devices and novel procedures could be tested are lacking. To meet this unmet need, we have developed a porcine model of juvenile obstructive hydrocephalus, and now report our experience in performing endoscopic third ventriculostomy (ETV) on this model.
Methods: Hydrocephalus was induced in 30-day old piglets by percutaneous intracisternal injections of 25% kaolin. Pre- and post-kaolin, and pre- and post-treatment (ventriculoperitoneal shunting and ETV), anatomic MRIs were obtained to document ventriculomegaly and guide the neurosurgical procedures. Animals survived 1–84 days (median 41) post-kaolin and 17 days (median 18) post-shunt; to date the ETV case was a terminal procedure.
Results: Lateral ventricle volumes progressed from 1291?+?188 mm3 SEM pre-kaolin to 2455?+?1067, 2821?+?1139, 2280?+?1836, and 3538?+?2043 at post-kaolin days 1–5, 8–15, 22–29, and 42–69, respectively. Ventriculomegaly continued to progress post-shunt (mean 4051 mm3). ETV was performed successfully using standard neurosurgical procedures; i.e. frontal approach, visualization of the foramen of Monro (FoM), and opening the floor of the 3rd ventricle with balloon expansion. The piglet survived the procedure and after brain fixation via cardiac perfusion the path through the FoM and the ETV could be confirmed grossly with minimal damage to adjacent tissue.
Conclusions: The juvenile piglet represents a good, clinically-relevant large animal model of hydrocephalus that is amenable to ventricular shunting and ETV. Cauterization of the choroid plexus also seems feasible.
