My veins are tiny so didn't cope well with chemo, it was rather sore and it took lots of attempts to get blood, get cannulae in etc. I did find that a hot water bottle or a hot wheat bag helped a bit with the aching after chemo. Oddly, touch wood, my veins seem to have recovered as my last blood test worked first time! Everyone had said they would be damaged for life so that was a nice surprise :) if you are offered a PICC line then I'd definitely go for it. Of course there are drawbacks but might be worth it to protect veins for future and also to relieve some of the pain.
mildmay do your unit give you a hot wheat bag to warm up your veins before they try to put the cannula in? I found that that helped a bit. In later cycles it took longer, once over an hour, but they did always manage to get one in eventually! Sorry I'm not up to date with the thread, do you have many cycles left? If so, it might be worth mentioning it to your onc, as they may recommend a line or portacath or something if it's going to be a problem.
greeneyed I've had a couple of similar procedures, the join from my pouch is quite tight so has been stretched a bit to ease things. It was under anaesthetic and I didn't have any problems with it. I don't know how similar it is for people with normal plumbing, but if I can be of any help, let me know. Though of course it's better if you can manage without it and avoid risks :)
BishB also second greeneyed's suggestion of hot water bottle. It's amazing how quickly you forget things, but I spent months sitting on mine. At first it was good for the soreness from the surgery, then when I started having skin problems and nerve pain. Not sure if it's particularly advisable but I found that almost burning it distracted me from the other pain! I used to feel a bit guilty as my hot water bottle has a little person on the cover and I felt bad putting her on my (clothed) bum 