Cellular Obstruction Clearance in Proximal Ventricular Catheters Using Low-Voltage Joule Heating.

Abstract

OBJECTIVE: Proximal obstruction due to cellular material is a major cause of shunt failure in hydrocephalus management. The standard approach to treat such cases involves surgical intervention which unfortunately is accompanied by inherent surgical risks and a likelihood of future malfunction. We report a prototype design of a proximal ventricular catheter capable of noninvasively clearing cellular obstruction. Methods: In-vitro cell-culture methods show that low-intensity ac signals successfully destroy a cellular layer in a localized manner by means of Joule heating induced hyperthermia. A detailed electrochemical model for determining the temperature distribution and ionic current density for an implanted ventricular catheter supports our experimental observations. RESULTS: In-vitro experiments with cells cultured in a plate as well as cells seeded in mock ventricular catheters demonstrated that localized heating between 43 °C and 48 °C caused cell death. This temperature range is consistent with hyperthermia. The electrochemical model verified that Joule heating due to ionic motion is the primary contributor to heat generation. CONCLUSION: Hyperthermia induced by Joule heating can clear cellular material in a localized manner. This approach is feasible to design a noninvasive self-clearing ventricular catheter system. SIGNIFICANCE: A shunt system capable of clearing cellular obstruction could significantly reduce the need for future surgical interventions, lower the cost of disease management, and improve the quality of life for patients suffering from hydrocephalus.