A 19-year-old male with no significant past medical history, except for a right femoropopliteal deep vein thrombosis (DVT) three months prior, presented with swelling in the posterior aspect of the right knee at the lower thigh. Examination revealed a pulsatile swelling (approximately 7 cm) located in the postero-medial aspect of the right thigh, with intact peripheral pulses and no signs of ischemia or hemorrhage. Imaging studies, including duplex ultrasound and computed tomography angiography (CTA), confirmed the presence of a pseudoaneurysm at the distal superficial femoral artery (SFA) measuring 9.5 × 6.5 × 4.5 cm, alongside an unusual bony prominence.
Surgical intervention was performed via a medial approach, including arterial control proximal and distal to the aneurysm neck, excision of the bony prominence, and resection of the pseudoaneurysm and the diseased arterial segment, followed by a short bypass using a saphenous vein graft. Postoperatively, the patient exhibited intact peripheral pulses, with transient joint effusion and limb swelling, which resolved without complication. The final diagnosis confirmed hereditary exostosis, with mechanical friction against the abnormal bony prominence leading to both the DVT and subsequent pseudoaneurysm formation.
This case highlights the potential vascular complications of hereditary exostosis, emphasizing the need for early recognition and intervention
