OCCULT DEEP VENOUS THROMBOSIS COMPLICATING SUPERFICIAL THROMBOPHLEBITIS

Purpose: To determine whether superficial thrombophlebitis (STP) can e xtend into the deep venous system (DVS) and whether this may result in pulmonary embolization. Methods: All venous duplex ultrasound examina tions performed in our vascular laboratory to rule out deep venous thr ombosis from Tune 1, 1994, to June 24, 1996, were reviewed. Results: O f 8313 limbs studied by duplex scanning in 6148 patients, 1756 limbs ( 21.1%) had a positive result for deep venous thrombosis. STP was demon strated in 232 limbs (213 patients), of which 20 (8.6%) extended into the DVS. Fourteen (70%) were noted on the initial scan, and six (30%) were detected on serial follow-up scans. Eighteen (90%) originated in the proximal greater saphenous vein and extended across the saphenofem oral junction into the common femoral vein. Nine demonstrated ''free-f loating'' thrombus with a ''tongue'' extending into the common femoral vein while still attached proximally to the greater saphenous vein. E xtension of thrombus from the lesser saphenous vein into the popliteal vein was noted in two cases (10%). One pulmonary embolization was dir ectly observed to occur in real time during scanning. No pulmonary emb olization was seen when STP did not involve the DVS. Conclusions: STP can extend into the DVS. In this series STP of the proximal greater sa phenous vein extended into the common femoral vein in 8.6% of the case s, of which 10% embolized to the lungs. When the DVS is involved, stan dard deep venous thrombosis treatment (heparin, warfarin, bed rest) sh ould be instituted. We recommend duplex imaging for STP involving the greater saphenous vein in the thigh to rule out occult deep venous thr ombosis. STP is not always benign and self-limiting as previously desc ribed.