Here's one overview. Hard to suggest something as people come from different backgrounds. You said your pressure was ok so they probably did one quick measure (either via shunt tap or lumbar puncture). But pressures change during the day. It could be your shunt system is at odds with how your pressures change.

http://emedicine.medscape.com/articl...50-overview#a1

Suggesting the surgeon remove a shunt that was recently deemed necessary is unlikely to sway their thinking unless they have proof that something is wrong. People could consider it malpractice. Is there someone who can go along with you to your appt to advocate for you if need be but who listens well otherwise?