Background <p>Abdominal aortic dissection aneurysm (AADA) with severe proximal stenosis often fails to meet the anatomical criteria for standard endovascular aneurysm repair (EVAR). We report a case of a Chinese Han woman in her 50s who declined open surgery and was successfully treated with an off-label use of a dedicated iliac branch device (IBD) system. This approach appears to be a promising solution for highly stenotic and tortuous aortic anatomy.</p> Case presentation <p>A Chinese Han woman in her 50s was diagnosed with an abdominal aortic dissection aneurysm during routine screening. Computed tomography angiography (CTA) revealed an infrarenal dissection with extreme proximal aortic stenosis (minimum diameter: 5.5 mm), an aneurysm measuring 23.2 mm in diameter, and a neck length of 11.5 mm. The procedure included balloon pre-dilation of the stenotic segment, coil embolization of the inferior mesenteric artery (IMA), deployment of a G-iliac™ main body stent and a SilverFlow™ iliac limb, adjunctive sac coiling, and simultaneous bilateral “kissing balloon” angioplasty. The patient recovered uneventfully. At one-year follow-up, CTA demonstrated a 13% reduction in aneurysm size, with no endoleak, stent migration, or occlusion, and complete resolution of symptoms.</p> Conclusion <p>The IBD system represents a viable minimally invasive option for patients with anatomically complex AADA, particularly when conventional EVAR is not feasible and open repair is declined. Tailored device selection combined with meticulous technique may expand the boundaries of endovascular therapy and offer a novel strategy for managing rare aortic pathologies.</p>