Unique Case of a 6 centimetre Ruptured Popliteal Artery Aneurysm Causing Thigh Compartment Syndrome

<b>Purpose:</b> This case highlights a rare and unique sequela following a popliteal artery aneurysm (PAA) rupture. The development of thigh compartment syndrome with haemodynamic instability as a consequence is exceptionally rare, as PAA rupture typically face resistance to rapid haemodynamic instability due to surrounding musculofascial and bony structures. To date, only 1 other published case report has documented a similar sequence of events.<b>Case Summary:</b> An 81-year-old male with a history of ischaemic heart disease, atrial fibrillation, and type 2 diabetes mellitus, but a lifelong non-smoker, presented in significant hemodynamic compromise due to a ruptured PAA. On examination, the affected extremity was swollen and tense, with sensory deficits distal to the knee, absent power in the hallux and ankle, and a faint dorsalis pedis pulse, but without evidence of acute distal ischemia. Computed tomography angiography (CTA) revealed a peripherally calcified ruptured right PAA, measuring 64 × 44 mm, accompanied by a substantial hematoma surrounding the aneurysm within the posterior thigh compartment. The patient underwent urgent endovascular repair followed by fasciotomies to manage the rupture and prevent further complications.<b>Conclusion:</b> This case demonstrates endovascular repair with a covered stent as a safe and effective alternative to open surgery in high-risk, unstable patients, allowing rapid aneurysm exclusion, limb salvage, and hemodynamic stabilisation. The patient provided informed consent for treatment and for the use of his clinical information in this case report.