The varicose tributaries of the superficial femoral vein passing into Hunter's canal.

In 1954 a woman was operated on for bilateral varicose long saphenous veins. The saphenofemoral junctions were tied and the saphenous trunks were stripped from the groin to the ankles. Six months later she returned with almost identical varices. How could they have filled? Reexamination showed that when the veins were emptied, and a tourniquet applied at the groin, on standing they immediately appeared, indicating a source of filling below the sapheno-femoral junction which, even if it had not been tied, was controlled by the tourniquet. The band was reapplied at the lower third of the thigh, i.e., at the distal end of Hunter's canal; on standing the veins remained empty, showing that the leaking point was above the tourniquet. At re-operation it proved to be at the centre of Hunter's canal. That a communicating vein entered the superficial femoral vein in Hunter's canal and could become incompetent was known from Turner Warwick's (I93i) and Dow's (I95I) studies, but this was the first time the writer had found it to be varicose. A further instructive experience was gained when a stripper introduced at the ankle into the internal saphenous vein did not appear in this vessel at the groin, but was ultimately found in the common femoral vein; it had entered the superficial femoral vein from the long saphenous vein by a varicose communicating vein passing through Hunter's canal (seen since on two occasions). Evidence of the incompetence of the Hunter's canal perforating veins has been given by venograms (Fig. i). These have shown varicosities passing downwards from the lower end and others passing medially from the middle and upper part of the canal, thus suggesting that more than one vessel might be defective; the operation findings described later confirm the presence of several vessels. These experiences indicated that when diagnosing varicose veins, tributaries of the superficial femoral vein passing into Hunter's canal must be considered. These vessels have been diagnosed and operated on 52 times, I2 being in untreated varicose legs (see Fig. 2), and 40 with persistent varices after operation on the long saphenous vein (Fig. 3). The left leg was affected 26 times and the right 24; it was bilateral in two. The sexes were equally affected.