It seems that any positive outcome has already been priced in. ISRG has increased 50% already YoY and 18% YTD. I'm afraid any surprise, if any, will be a risk to the downside.
I for one have already sold my position a few days ago. I generally don't hold any positions going into earnings reports because of the crazy volatility involved with the day traders that descend and such. I will look to jump back in after the report, though, of course that depends on the report itself.