Transonic transit time ultrasound volume flow measurements offers a surgeon quantitative data during the operation that indicates the functional success of the revascularization. Intraoperative flow measurements either confirm a qualitative visual anatomical assessment or prompt a reassessment while the patient is still in the operating room. Nevertheless, different groups within a hospital, all view surgery from their own perspective. Why Measure Interoperative Flow, therefore, can be answered differently depending upon the perspective of the inquirer.