Venous and arterial anomalies of the lower extremities diagnosed by duplex scanning.

The complex embryologic development of the vascular system often results in a myriad of clinically relevant anomalies. It has been stated that the classic anatomic venous pattern in the lower extremity is found in only 16 percent of patients. Previous studies on this topic are limited to isolated venous dissections or phlebography that lack complete anatomic detail. The recent introduction of high resolution duplex scanners for the assessment of veins of the lower extremity provides a unique opportunity to determine the incidence of anatomic variation. The current prospective study was done to identify venous or arterial anomalies apparent during routine duplex scanning of the lower extremity performed to rule out deep venous thrombosis (DVT). Limbs that had evidence of acute or chronic extensive DVT were excluded. Of 1,600 consecutive extremity scans, 946 extremities (59 percent) had no evidence of DVT. Of these, there were 43 patients with 64 anomalies in 57 extremities. The mean age of the group was 53.4 years. There were 24 women (55.8 percent) and 19 men (44.2 percent). There were 59 (92.2 percent) venous and five (7.8 percent) arterial anomalies. Duplication of the superficial femoral vein was the most common anomaly noted. Duplication of the deep femoral and popliteal vein was also noted. Unilateral anomalies were more common than bilateral anomalies, namely 67.4 versus 32.6 percent, respectively. Pain and swelling, common complaints in the patients with an anomaly, were noted in 71.4 and 45.7 percent, respectively. The frequency of deep venous anomalies of the lower extremities may be less than previously reported. Knowledge concerning the incidence and distribution of venous anomalies may lead to improved assessment and treatment of venous disease.