A 44-year-old Indian woman presents to the emergency room with complaints of right leg soreness and fatigue. The pain began after a long flight from South Africa two days ago. Her medical history includes diabetes, and she underwent a hysterectomy 10 days ago. She interrupted her post-surgery recovery to travel for a family emergency. She smokes one pack of cigarettes daily. Physical Examination: Obese and anxious. Afebrile. Right lower leg swelling with a calf circumference 4 cm larger than the left leg. Collateral superficial veins present. Entire leg swollen with pitting edema. Calf tenderness increases with gentle squeezing. Pain worsens with dorsiflexion of the right foot with the knee extended (Positive Homan’s sign). No redness of the leg. The patient was admitted to the hospital, and a lower extremity ultrasound confirmed the diagnosis. Which structure is most likely affected in this patient?
