I've had 2 shunts and 2 EVT's. Immediately after the first ETV, the shunt was removed. My cognitition being what it is (or isn't as the case may be) I am fuzzy on the logic behind the removal. Fortunately, I was able to catch the recent onset of hydro very early on and had a 2nd ETV before the condtion became too probelmatic. Good luck with your decision.