Fenestrated aortic endografts are used to treat aneurysmal aortic pathologies. These devices feature fenestrations at the origin of the renal and visceral arteries to preserve their patency. Traditionally, manufacturers determine the precise location of these fenestrations through specific measurements and complex mathematical calculations for each individual patient and/or non-standardized methods. Since every patient has a unique anatomy, the location of the visceral and renal vessels varies. To ensure proper alignment between the fenestrations and target vessels, fenestrated endografts are typically custom-made using a patient-specific approach by endograft producers. In urgency situations, when time is of essence, a tubular endograft can be manually modified by the surgeon to create fenestrations. However, this process is complex, requiring highly precise measurements and calculations, which increases the risk of potential errors. This patent introduces a simple, medical personnel friendly, algorithm for determining fenestration positions on the endograft.