I'm wearing this off to the right a tiny bit, to match your description of where your new kidney is... I smack it really hard, and my hand hurts a little bit now, but it was absolutely perfect load transition to a wide area, and zero "point" impact to the "centre right kidney". I seriously think this is what you're looking for.
Medical Disclaimer: I'm a person of reasonable intellect, with a tertiary degree, and I have had some injuries over the years whilst in pursuit of having fun, and I do have an understanding of your situation from your brief description, and I have an interest in medicine, and I almost became a Radio Imager, but I ended up in Estimating & Infrastructure Estimating as a profession. Therefore I have shown all care, but I take no responsibility. And besides, my Professional Indemnity Insurance doesn't cover a consultation like this! So in brief, DON'T sue me if anything goes wrong! I'm not "technically qualified" to give medical related advice...