@kaymorann4902, I see you are asking good questions about someone you care about who is living with a brain injury. My understanding is that shunts need to be replaced. "The average lifespan of an infant’s shunt is two years. Adults and children over the age of 2 may not need a shunt replacement for eight or more years. Shunt systems require frequent monitoring and follow-up." Read more here https://www.healthline.com/health/ventriculoperitoneal-shunt

It would be best to ask the neurologist about replacement and what an inactive shunt means. Has the shunt been replaced regularly?