Inclusion Criteria:  Kidney transplant recipient Informed consent signed  Exclusion Criteria:  BMI under 18kg/m2 BMI over 40 kg/m2 Significant anatomical abnormalities of lower urinary tract Previous surgery on bladder or urinary tract Unusual urinary anastomosis (Leadbetter-Politano, Boari, conduit, psoas hitch, pyelo-ureteral or uretero-ureteral, double ureter) Severe vascular complications during surgery with blood loss >1000 ml Underwent haemodynamic shock or profund instability after surgery