Does the Addition of Routine IVC/Iliac Vein and Infrapopliteal Duplex Scan Confer any Benefit?

Abstract

The routine evaluation for lower extremity deep vein thromboses (DVT) usually involves the femoral and popliteal veins with no regard to the more proximal (Iliac and inferior vena cava [IVC]) veins or the more distal (infra-popliteal) veins. In this study, we attempted to evaluate the benefits of routine scanning of these segments. We reviewed 1624 consecutive lower extremity venous duplex studies performed for 1513 of our in-house patients between January 2008 and July 2008. All studies included routine evaluation of the IVC/iliac and infra-popliteal vein segments. All studies were also evaluated for any evidence of pulmonary embolism (PE). The IVC/iliac vein segments were completely evaluated in 1270 duplex studies with evidence of IVC/iliac vein DVTs in 37 (2.9%). In 354 studies, the evaluation was incomplete due to improper visualization of the IVC mostly due to bowel gas. Despite that, evidence of iliac vein DVT was noted in 18 (5.1%) of these studies. In total, the addition of routine iliac vein/IVC duplex scan resulted in the detection of 55 (3.38%) DVTs with evidence of PE in five (incidence of 9.1%). In five of those 55 duplex studies, the IVC/iliac vein DVT was the only DVT detected, with evidence of PE in one (incidence of 20%). The rest of the study population had evidence of DVT in 244 studies (15.55%) with evidence of PE in 32 (incidence of 13.1%) of them (P = .59). Infra-popliteal segment: 145 infra-popliteal DVTs were detected, of which 50 (34.5%) were isolated to the infra-popliteal segments with evidence of PE in three (incidence of 6%). The rest of the study population showed evidence of DVT in 98 with evidence of PE in 14 (incidence of 14.3%) (P = .135). Although routine scanning of the IVC/Iliac veins resulted in detection rate of 3.38%, the detection of an isolated DVT in those veins was very low (0.3%). However, isolated DVT of the iliac veins had a PE rate of 20%. As for the routine scanning for infra-popliteal DVTs, 50 additional DVTs were detected with a PE rate of 6%, with no statistical difference from the rate of PE from more proximal segments (P = .135). Hence infra-popliteal DVTs should be regarded as risky as more proximal DVTs and should therefore be treated similarly.