BACKGROUND Thrombus regression in heparin-treated, acute deep venous thrombosis of the lower extremity is poorly documented in the literature; different rates of thrombus resolution and recanalization are reported. METHODS AND RESULTS In a prospective follow-up study, duplex scanning was used to evaluate the thrombus regression in patients with documented acute femoropopliteal thrombosis. Eighty vein segments in 20 legs of 18 patients were subjected to repeat duplex scans at 1, 3, 6, 12, and 26 weeks after diagnosis; 49 segments showed thrombus at diagnosis. The popliteal vein showed the highest thrombus load at diagnosis, followed in descending order by the superficial femoral, profunda femoris, and common femoral vein segments (p less than 0.001). Thrombus regression was significant (p less than 0.001) in all segments and proceeded at an exponential rate that was equal in the different vein segments of the upper leg. Both thrombus resolution and recanalization appeared to be a function of the initial thrombus load and could not be related to individual vein segments. Recanalization was seen in 23 of 31 initially occluded segments and occurred within the first 6 weeks after diagnosis in 20 of 23 segments. Extension of thrombus despite anticoagulant therapy was observed in 15 vein segments and was not related to the initial thrombosis score (p = 0.1) or individual vein segments (p = 0.23). Thrombus extension in seven patients with prethrombotic conditions was not different (p = 0.9) from the other patients. CONCLUSIONS Duplex scanning is an important noninvasive tool to quantify thrombus regression in acute deep venous thrombosis in detail without unnecessary discomfort to the patient.
To detect haemodynamically significant lesions in the aortoiliac arteries, invasive tests such as angiography and intra-arterial pressure measurement (IAPM) are considered valuable diagnostic tools. The value of duplex scanning as a direct non-invasive examination technique was prospectively compared with intra-arterial digital subtraction angiography (IADSA) and IAPM at rest, and after the administration of papaverine in 60 patients. Excellent agreement, as assessed by the kappa statistic, was shown between duplex scanning and IADSA (kappa = 0.81). A fair agreement was shown between duplex scanning and IAPM (kappa = 0.63), and between IADSA and IAPM (kappa = 0.63). Duplex scanning and IADSA both missed some less haemodynamically critical lesions if IAPM was considered the 'gold standard'. It is concluded that duplex scanning detects haemodynamically significant lesions as effectively as angiography and so may be considered a new and valuable diagnostic tool. IAPM remains necessary to detect some lesions of borderline haemodynamic significance. However, with future developments, duplex scanning has the potential to replace the need even for IAPM.
Purpose: Duplex ultrasonography with distal cuff deflation was used to establish the physiologic reflux duration in different segments of the deep venous system in healthy individuals, and to document the occurrence of deep vein valve incompetence in patients after deep vein thrombosis (DVT). Methods: Two hundred fifty-two vein segments in 42 legs of21 healthy individuals and 160 deep vein segments in 27 patients with phlebographic ally documented DVT were examined with duplex scanning. Results: The duration of reflux in healthy subjects was significantly shorter in distal deep vein segments. Ninety-five percent of the values were less than 0.88, 0.8, 0.8, 0.28, 0.2, and 0.12 seconds, respectively, for the common femoral, superficial femoral, deep femoral, popliteal, and posterior tibial vein (at midcalf and ankle level). The 95 percentile for reflux duration in the superficial venous system was 0.5 seconds for all vein segments, regardless of the location. No significant correlation was found between the reflux peak flow velocity and reflux duration (R = 0.6). The reflux peak flow velocity is therefore not useful as a parameter of the degree of reflux. The patient group was examined with an interval of 18 to 51 months (mean 34 months) after DVT. Forty-five percent of the initially affected segments showed valve incompetence at follow-up (n = 54); only three of 40 segments initially free from thrombus showed pathologic reflux at follow-up (p < 0.01). Reflux durations in most of the incompetent vein segments were two or more times the normal value of reflux duration. The highest prevalence of valve incompetence was found in the superficial femoral and popliteal vein segment (p < 0.01). None of the patients showed valve incompetence at all levels of the deep venous system. A significant (p = 0.04) relation was found between the extent of the initial thrombosis and the number of refluxing vein segments at follow-up, but no correlation was found between the extent of initial thrombosis and the late clinical symptoms (p = 0.16); clinical symptoms could not be related to the number of incompetent vein segments. Conclusions: Duplex scanning allows a good discrimination between physiologic and abnormal reflux duration and is an important tool in the evaluation of the postthrombotic limb. Early assessment after DVT may have prognostic value in individual patients.
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