I had pec repair surgery 24 months ago and since then my whole hand frequently gets swollen and kind of numb. What's affecting my hand?

Congestion. may be venous or lymphatic congestion developing from the surgery or scar tissue formation after the surgery. May be prudent to see a vascular physician and possibly have Doppler study of arm. Gentle exercise of arm and hand on regular basis may also stimulate formation of new channels that may help swelling.