Waldo, I know some of these medical places can be very `` fussy``..in my opinion, if you did a full detach/clean/re-attach the night before, there should be no issue....your scalp and [system] hair would be just as clean as the rest of you .....in any case, they always put a head-cap on you for any procedures...... I was interested in your thread because I was diagnosed with the same condition a few months ago [ well ,a stomach hernia].... I wear a Fullcap..... I had to go to the hospital as an `out-patient` [day-procedure] to have the camera put down ...I didn`t take sedation, so was fully conscious for it....they put a head-cap on me, even though it was a non-invasive [surgery] procedure......it`s standard. I didn`t tell them I was wearing...never really entered my mind to be honest. If I eventually decide to have surgery to correct the condition, I will be in the same position as you now are. I can`t see why a topper or even Fullcap should cause any issue for anyone..they won`t be operating on your head and it will be fully covered in a head-cap with an elasticated perimeter.......and by the way, I also had a double-strap thing placed around my head [after the head-cap was in place] in order to hold a plastic thing [like a baby`s soother] into the mouth to hold it open, with a hole in the middle of it, through which they passed the camera-tube [endeoscope]..... it made no difference to anything , the fact that I was wearing...... they ask a few questions and tick a few boxes on a form before the procedure, and you then sign a `disclaimer`form [ if we butcher you --it`s your problem basically !!] --there were no questions on it regarding hair-systems. By the way, do you really really need to have this operation done ? It`s tricky enough I`m told i.e. not always very successful[stomach hernia]... I read-up about it on line and there was a forum I saw, where people were of mixed-views and had varying results too..... well that is a stomach hernia...maybe yours is abdominal, in which case you`ll have to have it done or it will worsen, but the fact that you wear should not be an issue in my opinion...... any patient who needed surgery to the head would have to just shave most of their hair anyway or in the case of a wearer, just simply remove the system, but for anything from the neck down, I can`t see what the ``big deal`` would be...as long as you`d go in with freshly-shampooed hair and a clean bond, there should be no issue.