Tĩnh mạch đục lỗ nên được đánh giá cho năng lực. Thiếu năng lực của tĩnh mạch khoan tồn tại nếu có sâu, bề mặt dòng chảy còn hơn 0,5 s nén hướng dẫn sử dụng ở trên hoặc dưới đầu dò siêu âm [9]. Các tĩnh mạch thuộc về nhượng chân được kiểm tra trong ba phân đoạn: xa, gần, | 138 Jonith Breadon perforating veins penetrating the muscle fascia that communicate with the long saphenous system and femoral vein should be examined. Perforating veins should be assessed for competency. Incompetence of perforator veins exists if there is deep-to-superficial flow for longer than s on manual compression above or below the ultrasound transducer 9 . The popliteal vein is examined in three segments distal to proximal to and at the same level of the sa-phenopopliteal junction. The saphenopopliteal junction if located should be assessed. The short saphenous vein is examined for competence in the proximal mid and distal calf segments. Examination of the medial and lateral calf veins takes place with the patient sitting with the leg extended horizontally and the foot resting on the examiner s knee with the calf muscle relaxed. Assessment of the proximal calf segment of the long saphenous vein is examined for competence and patency from the knee to ankle. The posterior arch vein can also be located and assessed in most patients. Calf-perforating veins from the posterior arch complex gastrocnemius and soleal perforators or posterior tibial perforators can be identified and examined for competency by compression above and below the transducer 9 . Deep-to-superficial blood flow greater than s on calf or foot compression is considered incompetent. Distal segments of the gastrocnemius vein can similarly be assessed. Doppler studies should also be performed on the posterior tibial vein from the proximal calf to the ankle. The peroneal vein is examined from the same transducer position. The anterior tibial vein only needs assessment in suspected cases of deep venous thrombosis. Routine assessment of the lateral calf and soleal veins is unnecessary unless there are obvious lateral calf varices 9 . Duplex venous scanning is the most advanced modality used to investigate venous disease in the sclerotherapy patient. Duplex scanning is important in the .
