The present disclosure relates to laparoscopic surgery, and in particular to laparoscopic ports for facilitating the implant of medical systems such as a neuromodulation system into the body of a patient. Particularly, aspects are directed to a cannula assembly having a cannula housing and a cannula sleeve comprising a sleeve body extending from a distal end of the cannula housing. The cannula sleeve has a semi-rectangular cross section including: (i) a rounded rectangular portion configured to accommodate feeding the neuromodulation system through the cannula assembly, and (ii) a circular portion configured to accommodate insertion of the one or more surgical instruments through the cannula assembly.