A novel coaxial tube catheter for central nervous system infusions: performance characteristics in brain phantom gel

Abstract

We tested a novel neurocatheter in a brain-tissue gel model of drug infusion via convection-enhanced delivery (CED) for the treatment of a variety of neurological diseases. CED is an alternative to systemic administration of agents by intravenous or oral routes, which are often less effective or carry risk of systemic side effects. We investigated two co-axial tube devices, with outer diameters of 1.6 mm and 2.0 mm. Bromophenol blue dye was infused into 400 ml of 0.6% agarose gel at 1 μl/min for 1 h, with/without the inner and outer tubes Luer-locked at the proximal end, with/without the inner tube primed, and with/without the inner tube preloaded into the outer tube upon insertion into the gel. The unlocked, primed, and unloaded configuration produced infusions that resulted in significantly less (p < 0.05) entrapped air escaping into the gel and resulted in no reflux of infusate.

Convection enhanced delivery of panobinostat (LBH589)-loaded pluronic nano-micelles prolongs survival in the F98 rat glioma model

“…2,3 CED describes continuous infusion of agents under pressure through stereotactically placed micro-catheters. 4 This method has several potential advantages over conventional drug delivery methods. CED facilitates highly accurate anatomical drug targeting, delivery of high drug concentrations throughout clinically relevant volumes of brain tissue or tumor, and reduces systemic side effects.…”

Image-guided Convection-enhanced Delivery into Agarose Gel Models of the Brain

“…It may also cause local tissue disruption and affect the distribution of the infusate. A successful study was performed using coaxial catheters that yielded parameters to minimize or eliminate the effects produced by air escape into the infusion site 23 . From our study, we identify a need for future investigations into proper methods of CED infusions using single cannula catheters such as the SmartFlow catheter to equally minimize or eliminate the presence of air.…”

“…While backflow can occur at any point during an infusion, there is an increased incidence of backflow at the start of the infusion and when increasing the infusion rate 10 . Backflow has also been associated with the presence of air bubbles, catheter insertion technique, and catheter design, though back flow may still occur despite controlling for these variables 23 . To minimize backflow, a stepped, reflux resistant catheter was used, and the infusion rate was held constant and as low as possible (1.667 μl/min).…”

Performance tests of a novel coaxial tube catheter in anin vitromodel of intracranial cell delivery

“…As described in detail in our companion paper [7], the new catheter had a co-axial design consisting of one polyetheretherketone (PEEK) tube inside of another. The inner tube had a single side-port hole on the distal end, while the outer tube had four of them arranged in a spiral pattern near the distal tip.…”

“…As part of our overall effort on developing new methods for convection-enhanced delivery (CED) of agents into the brain for several different applications [4,5], we have developed a novel co-axial tube neurocatheter [6] and tested it via the positive pressure infusion of dyes into an agarose gel model of the bulk brain tissues. The results of that work suggested a configuration of the device [7] that might be especially useful for the intraparenchymal delivery of cell suspensions. Therefore, it was the goal of the present study to develop an appropriate in vitro model of cell delivery into the central nervous system and use it to examine this possibility.…”