cystectomy (n.)

"bladder-like bag or vesicle in an animal body," 1713, from Modern Latin cystis (in English as a Latin word from 1540s), from Greek kystis "bladder, pouch," which is of uncertain etymology.

word-forming element meaning "surgical removal," from Latinized form of Greek -ektomia "a cutting out of," from ektemnein "to cut out," from ek "out" (see ex-) + temnein "to cut" (from PIE root *tem- "to cut").