pyelostomy

noun
py·​e·​los·​to·​my | \ ˌpī-(ə-)ˈläs-tə-mē How to pronounce pyelostomy (audio) \
plural pyelostomies

Medical Definition of pyelostomy

: the operation of forming an artificial opening in the renal pelvis of a kidney in order to provide a drainage route for urine alternative to the ureter