A drug-delivery cannula assembly includes a cannula housing adapted for receiving at least one obturator shaft of an obturator assembly therethrough, one or more cannulae, and a supply line coupled to the cannula housing. The cannula housing is adapted for receiving one or more obturator shafts of an obturator assembly therethrough. The one or more cannulae define a longitudinal axis and a passageway aligned with the longitudinal axis. The one or more cannulae each include a proximal end coupled to the cannula housing. The cannula housing is configured to fluidly-couple the one or more cannulae to a source of a drug delivery supply for supplying drugs via the supply line to the one or more cannulae.