Inclusion Criteria:  Age ≧ 19 Patients undergoing radical cystectomy with neobladder reconstruction Patients undergoing radical cystectomy with ileal conduit urinary diversion  Exclusion Criteria:  Unable to voluntarily give consent Unable to use both radial arteries due to such reasons: prior surgery on the radial artery, breast cancer history with axillary LN dissection, AV fistula for renal replacement therapy, or abnormal Allen's test.