My Neurosurgeon planned to do 22600, 22614, 22842, 63045, 63048 X2, 20930. This procedure was aborted due to blood pressure drop when patient was placed prone. We billed these out with 53 modifier since anesthesia was administered. Pt was kept in hospital and 2 days later he did Anterior approach surgery, 22551,22552,22845,22851 X2, 20930. What modifier to I append to the second surgery?