nephrotomy

from WordNet (r) 3.0 (2006)

nephrotomy
    n 1: incision into a kidney (usually to remove a kidney stone)

from The Collaborative International Dictionary of English v.0.48

Nephrotomy \Ne*phrot"o*my\, n. [Gr. nefro`s a kidney + te`mnein
   to cut: cf. F. n['e]phrotomie.] (Surg.)
   Extraction of stone from the kidney by cutting.
   [1913 Webster]