The saphenopopliteal junction - Can you put your finger on it?

Objective. Duplex marking is the generally preferred method for pre-operative localisation of the saphenopopliteal junction (SPJ). However, patients with short saphenous incompetence usually have a palpable short saphenous vein (SSV) in the popliteal fossa. This study was undertaken to determine whether the upper end of a palpable SSV correlates with the SPJ. Should it do so, pre-operative duplex marking could be omitted. Design, materials and methods. A prospective study of 50 consecutive primary SSV ligations was undertaken. The palpatory location (PL) of the top end of the SSV and the duplex predicted site of the SPJ were exactly marked and compared with the subsequent operative findings. Results. Duplex was accurate to within 10 mm in 43 (86%) and 20 mm in 49 (98%) cases. Palpation was accurate to within 10 mm in only 10 patients (20%). The PL missed the SPJ by 10-20 mm in 14 and by more than 20 mm in 26. The mean distance between PL and SPJ location was 21 mm (range 0-53). The SPJ was located above and lateral to the PL in all but three cases (94%). When duplex was inaccurate the SPJ was in most cases either below or medial to the duplex location. Conclusion. Palpation of the SSV trunk alone is inaccurate in locating the SPJ. Duplex remains the gold standard for the pre-operative localisation of the SPJ.