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Modelling health solutions: hydrocephalus

One of Siv’s many projects is modelling the optimal placement of shunts in hydrocephalus patients. Cerebrospinal Fluid (CSF) produced in the brain ventricles circulates around the brain and spinal cord providing nutrients, removing waste products and is eventually reabsorbed into the bloodstream. Hydrocephalus — an accumulation of CSF — typically occurs when absorption is inadequate. Excess CSF causes enlarged ventricles, elevated intracranial pressure and as a result, compression of the brain tissue. To treat this, a shunt is inserted into the ventricle to drain excess fluid. As the brain “bounces back” the shape is not uniform and the shunt may end up occluded, requiring a second operation (within two years) in almost 50% of cases.

Unfortunately, most cases of hydrocephalus involve children. When Siv and his colleague Pino Tenti began to work with doctors at Sick Kid’s Hospital in Toronto, they looked for ways to improve the positioning of the shunt on the primary operation. Siv’s team approached the problem with a multi-disciplinary mindset that included: poro-elastic engineering, understanding of the visco-elastic properties of biological tissue, computer algorithms and non-linear equations.

“The software program we developed models how the ventricle would respond after shunt insertion. Coupled with their experience, the neurosurgeon would have greater confidence in placing the initial shunt. In many cases, eliminating the need for a second operation,” explains Siv.

Siv is an applied mathematician by training, working in fluid dynamics and differential equations. But his passion is applying his mathematical understanding to medicine. Siv is the founding director of the Centre for Mathematical Medicine at the Fields Institute in Toronto, launched in 2005.

University of ��ݮ��Ƶ Mathematics, Annual Report 2005