Tell (email) your AME in advance. I suspect he will tell you how long you are grounded and simply ask for the summary from your consultant. You will be sore but depends on the size of the hydrocele.
Open procedure every time. Both can be done awake or anaesthetised. Success rate the same with both. Embolisation needs X rays, contrast (allergic reaction!) and the risk of the agent going elsewhere. Dont use a hammer to crack a nut as they say.