The Approach Open is identified by number "0" and occupies the 5th position in the ICD10-PCS procedure code structure.
Below a selection of ICD 10 PCS codes related to 0NN40
Release Left Parietal Bone, Percutaneous Approach
Release Left Parietal Bone, Percutaneous Endoscopic Approach
Release Left Parietal Bone, Open Approach