Background/Objectives: Physician-modified endografts (PMEGs) have emerged as a treatment option for complex aortic pathologies. Uncertainty remains regarding the modification techniques and the most suitable materials for customization of fenestrated endografts. The aim of this study was to evaluate CE-marked endovascular aortic repair (EVAR) devices and suitable materials for device modification in PMEGs for juxtarenal and pararenal aortic pathologies. Methods: This single-center observational study included patients treated with the physician-modified TREO (Terumo Aortic, Inchinnan, UK) device between April and December 2024. All patients had aortic ruptures or symptomatic aneurysms and unfavorable anatomy or severe comorbidities, making standard EVAR and open repair unsuitable. Procedural data were recorded and analyzed, including in-hospital outcomes. The “wire visibility” and “sheath–wire contrast” of endografts were assessed under fluoroscopy, and different resheathing techniques were compared. Results: Technical success was achieved in all five patients. The number of fenestrations per patient was 2.6 (range: 1–4). In one patient (1/5), type Ib and type IIIc endoleaks were observed postoperatively, requiring reintervention. No in-hospital mortality occurred. The ICU and hospital stay were 24 h (range: 18–40 h) and 8 days (range: 6–20 days), respectively. Moreover, the One SNARE wire was identified as the wire with the highest “wire visibility”, and Endurant II showed the best “sheath–wire contrast”. Resheathing with the dedicated crimping device was superior to the tape-assisted method. Conclusions: The TREO platform, in synergy with suitable additional materials, offers a viable solution for urgent aortic pathologies requiring PMEGs. Continued refinement of materials and procedural standardization could enhance the long-term outcome.