Cystic adventitial disease is a rare non-atheromatous cause of popliteal artery disease. We report a case of a 54-year-old patient with claudication of the right calf caused by cystic adventitial disease. Intra-operatively, a communication between the adventitia and the knee joint was identified. Connections between the adventitial cyst and the nearby joint have been reported in the literature that support the developmental theory. This theory suggests that cystic adventitial disease is a developmental manifestation of mucin-secreting cells derived from the mesenchyme of the adjacent joint. This case is the first, to our knowledge, in which a communication between joint and adventitia has been clearly documented by operative findings.

The management of mural thrombus in NAADTA represents a challenge, especially in case of malignant disease or hypercoagulable disorder as a potential underlying pathology and should be individualized. Although no consensus exists in the literature, therapeutic anticoagulation is proposed as first-line therapy. The indication for surgical intervention results from contraindication to anticoagulation, mobile thrombus or recurrent embolism. Whenever possible, endovascular therapy should be preferred.

This present study provides evidence that aneurysm size ≥60 mm is independently associated with worse survival during follow-up.