No additional testing is indicated in this patient. The patient's isolated bilateral lower extremity edema is most likely due to chronic venous insufficiency, as supported by the otherwise normal examination findings and lack of abnormal laboratory test results, and no further diagnostic studies are indicated. The edema associated with chronic venous insufficiency typically is insidious in onset. It worsens with prolonged standing and is improved with elevating the legs and with walking. Leg discomfort is also often gradual in onset and is described as a tired or heavy sensation in the legs. Other symptoms can include pruritus, skin discoloration, and ulceration. Compression stockings are considered first-line therapy for patients with lower extremity edema due to chronic venous disease. The patient should be instructed to put on these stockings in the morning before edema is present and to wear the stockings as much as possible when he is in a standing position. The stockings can be removed at night.

Obtaining an abdominal/pelvic CT scan in this patient would not be appropriate, as he lacks signs and symptoms that would suggest abdominal or pelvic pathology.

Lower extremity venous duplex ultrasonography is not necessary in this patient who lacks risk factors for deep venous thrombosis (prolonged immobility, known cancer history, or use of predisposing medications) and does not have a clinical picture consistent with bilateral deep venous thrombosis.

In the absence of symptoms and examination findings that suggest heart failure (such as orthopnea, dyspnea, paroxysmal nocturnal dyspnea, elevated central venous pressure, crackles in the lower lung fields, and S₃ and/or S₄ heart sounds), the diagnostic utility of a transthoracic echocardiogram is likely low and therefore not appropriate in this patient.