CPT code 33858 designates open surgical repair of an aortic dissection with graft placement, performed with initiation of cardiopulmonary bypass and possible suspension of the aortic valve within the graft. This procedure is a high-acuity, resource-intensive cardiothoracic operation with implications for operative planning, facility capability, and national payment policy for complex vascular surgery. It is relevant to hospital payment systems, inpatient surgical quality measures, and risk adjustment for postoperative care. Key payers covered in the analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find clinical context for the service, the typical inpatient operating-room setting, and the procedural elements that drive resource use. The publication outlines what to expect in terms of service classification, common modifiers and coding considerations (where available), and the relationship of the code to broader cardiovascular surgical care. Benchmarks and payer policy summaries are provided where data exist. Data not available in the input is noted when applicable. This summary is intended for coding professionals, hospital billing analysts, and policy stakeholders seeking a concise national overview of CPT code 33858.