The greater saphenous vein is a superficial vein, which receives venous blood from the anterior medial calf and the foot and runs up along the medial aspect of the thigh. The common femoral vein is usually 2–4 cm in length, receiving three tributaries, being the great saphenous vein (superficial vein), profunda femoral vein and femoral vein (deep veins). Sonoanatomy of the lower extremity venous system. In this review, the evolution and method of lower limb venous compression ultrasound is described along with evidence for its use in emergency medicine, critical care and the current evidence for its use in pre‐operative screening in patients at high risk for DVT. This technique is usually referred to as lower limb venous two‐ or three‐point compression ultrasound, depending on the number and site of compression points, and is becoming popular in emergency, critical care and perioperative medicine. It has been realised that inability to completely compress the vein with the ultrasound probe has an equivalent accuracy (false‐positive and false‐negative predictive value) to venous duplex, and this technique can be easily taught to non‐radiologists and non‐sonographers, enabling point‐of‐care application and therefore potentially saving considerable time and cost of referring patients to the radiology department. The basic principles of ultrasound identification of DVT (known as ‘venous duplex’) are visualisation of a thrombus within vein lumen, which results in reduced or absent blood flow in the vein using colour flow and spectral Doppler. Venography is now usually reserved for when ultrasound is not adequate or available. In many regions, ultrasound has replaced venography as the first‐line investigation of choice for DVT 8, 9, 10, 11, 12, 13 due to its comparable (but slightly lower) accuracy 9, 13 with the lack of exposure to staff and patients to radiation and lack of exposure to patients to intravenous contrast. 6 It is estimated that many more cases of DVT are not diagnosed and hence improvements in diagnosis of VTE is a priority. 2 Approximately 2 million patients are diagnosed with a deep venous thrombosis (DVT) annually in the United States, 3 resulting in estimated 600,000 hospitalisations and 200,000 deaths resulting from pulmonary embolism (PE), 4, 5 and the short‐term mortality rate from untreated pulmonary embolus probably exceeds 20%. Venous thromboembolism (VTE), which comprises deep venous thrombosis (DVT) and pulmonary embolus (PE), is the third commonest vascular disorder in Caucasian populations, 1 and in Australia, DVT alone (without concomitant PE) affects 52 persons per 100,000 annually.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |