Lesser saphenous vein thrombosis diagnosed by point-of-care ultrasound in a patient presenting with pulmonary embolism.

In recent years, much controversy has surrounded the topic of anticoagulation use in cases of superficial venous thrombosis. There is increasing evidence to demonstrate that these clots can spread to the deep venous system and pulmonary vasculature if left untreated. The most common culprit is the greater saphenous vein [1]. Lesser saphenous vein clot is thought to have a much smaller likelihood of evolving into a deep venous thrombosis (DVT), although the exact occurrence rate is uncertain [1]. We describe a case of a patient presenting with lower extremity swelling that was ultimately diagnosed as being caused by lesser saphenous vein thrombosis. The diagnosis was made by point-of-care ultrasound, and the patient was also diagnosed with a concomitant pulmonary embolism. A 42-year-old woman presented to the emergency department (ED) complaining of right calf pain accompanied by mild swelling. She additionally experienced increasing exertional dyspnea since returning to the United States from Guatemala 11 days prior. She appeared comfortable with normal vital signs and an unremarkable physical examination, outside of the described edema. There were no additional risk factors for thromboembolic disease. An ECG revealed sinus bradycardia, and a chest X-ray study was normal. A focused ultrasound of the right lower extremity performed by the emergency physician showed a right lesser saphenous venous thrombosis extending near the right popliteal vein (Fig. 1). The patient was also diagnosed with a segmental pulmonary embolism extending from the bifurcation down into the right lower lobe via CT angiography that was completed shortly after the ultrasound study. Heparin therapy was initiated, and later transitioned to Xarelto 15 mg twice a day. The patient was discharged the following day in stable condition. Ultrasound evaluation for DVT of the lower extremity involves graded compression of the femoral and popliteal regions, classically utilizing a high frequency linear transducer. Findings of deep venous thrombosis include non-compressibility of the vein, direct visualization of thrombus in the vessel lumen, absence of phasic respiratory variation, and lack of Doppler augmentation with calf compression or ankle plantar/dorsi-flexion. A thrombus found within 3 cm of the saphenofemoral junction is treated as a deep venous thrombosis [1]. During a focused evaluation, the lesser saphenous vein and other superficial veins are typically visualized, and a superficial thrombophlebitis or thrombosis may be revealed as in the case with our patient by using the same graded compression technique mentioned above. In addition, a repeat ultrasound study following a negative study is always recommended in 5–7 days as propagation of a more subtle clot can occur. Thus, the location and proximity of superficial venous thromboses (SVT) plays an important role in whether or not the patient requires anticoagulation. Superficial venous thromboses are common, accounting for 30 % of documented venous thromboses or approximately 125,000 cases per year in the Unites States population [2, 3]. A study by Decousus et al. reports that 198/844 (23.4 %) patients with SVT have an associated DVT [1]. Of this group, 72.7 % of greater saphenous vein thromboses are associated with DVT while 26.3 % of lesser saphenous vein thromboses are associated with DVT. Superficial venous thrombosis usually presents with pain, swelling, and erythema, and historically were treated & Adam Ash adamash4@hotmail.com