Скачать или смотреть Ink Test of a Ventricular Catheter

Stephanie TerMaath is an assistant professor in the Mechanical, Aerospace, and Biomedical Engineering Department at the University of Tennessee, Knoxville, and an affiliated faculty member of the Joint Institute for Computational Sciences (JICS).

The aim of one of her research projects is to improve the ventricular catheter component of shunts used to treat patients with hydrocephalus (intracranial pressure caused by an accumulation of cerebrospinal fluid in the brain's ventricular system).

Currently, well more than 50 percent of shunts require revision over the course of their lifetime. Some need multiple revisions. Statistically, hydrocephalus patients require two to four brain surgeries for shunt insertion or revision in a 10-year period after their initial diagnosis. One of the primary causes of failure and reoperation is obstruction of the shunt tubing, which typically necessitates a surgical procedure to replace the obstructed portion. Obstruction of the catheter in the ventricle is responsible for about one-third of all shunt revision operations. This blockage may result from the accumulation of blood or debris on the inner surface of the catheter or the entry of fronds [portions of the brain's white matter] or choroid plexus [epithelial tissue] into perforations in the proximal end of the catheter, preventing fluid entry. There is no universal agreement on what shape and size of catheter perforation are ideal to allow optimal fluid flow and minimize the aggregation of material within the catheter while mitigating entry of choroid plexus into the perforations. Given the life-or-death impact of shunt malfunction on patient health and the high percentage of shunt revision surgeries, an improved design of the ventricular catheter is imperative.

The initial objective of TerMaath's medical device optimization research is to integrate supercomputing simulation and experimental testing to improve the design of ventricular catheters such that uniform flow through all holes is achieved. These catheters are a critical component in a shunt system, but obstruction of the tubes is largely responsible for shunt failures and revision surgeries. In the current design of the catheter, cerebrospinal fluid flow is primarily through one group of holes, the first ring of proximal holes around the circumference. With this design, if any solid matter flows into the tube causing a blockage, all holes are then ineffective. With all of the holes accommodating CSF flow, the probability of complete obstruction is reduced. TerMaath’s hypothesis is that catheter redesign that is optimized for uniform flow across holes will reduce the obstruction rate.

Video credit: Sofy Weisenberg, the University of Tennessee, Knoxville