[Prospective 12-year follow-up study of clinical and hemodynamic sequelae of deep venous thromboses in patients with low risk (Zurich Study)]. / Prospektive 12-Jahres-Verlaufsstudie über klinische und hämodynamische Folgen tiefer Venenthrombosen bei Patienten mit niedrigem Risiko (Zürich-Studie).

No prospective study of the long-term sequelae of more than 10 years after acute deep vein thrombosis exists so far. Therefore, 28 patients with DVT were included in a prospective study to evaluate the natural history of postthrombotic syndrome. Clinical and hemodynamic examinations were performed at the time of admission; after 3, 6 and 12 months; after the 2nd, 3rd, 4th, 5th; and finally after the 12th year. All patients received unfractionated heparin initially and oral anticoagulants subsequently. After 12 years, 64% of the patients exhibited normal findings. Mild skin changes were found in 28%, marked trophic changes in 5%, and only 1 venous ulcer occurred. Regular use of compression stockings was reported by 54% of the patients with multilevel disease. Although mean maximum venous outflow was significantly reduced from the acute event to 2 years later (p < 0.003) compared with the contralateral leg, a significant (p < 0.05) improvement was observed 6 months later. Recanalization of calf vein thrombosis was detected by Doppler sonography after 3 months. 64% of the multilevel thromboses were recanalized completely or in part after 1 year; in 69%, valvular incompetence was found. In conclusion, in contrast to earlier reports, this prospective study up to 12 years after DVT demonstrates a low incidence of PTS by administration of initially unfractionated heparin, oral anticoagulation and compression therapy. However, the adverse clinical event rate (mortality 14%) and recurrency rate of 24% show that the prognosis after DVT does not appear favorable even in low-risk patients.

On the relationship between changes in the deep veins evaluated by duplex sonography and the postthrombotic syndrome 12 years after deep vein thrombosis.

In a prospective study we performed color duplex ultrasonography to evaluate patency and valvular function of previous thrombosed veins 12 years after the acute thrombosis. Normal clinical findings were found in 64% of the patients, mild postthrombotic skin changes in 28%, and marked trophic changes in 5%; only 1 venous ulcer occurred. In 39 patients, 114 initially thrombosed vein segments were evaluated. Thirty-seven of 72 proximal segments were completely recanalized (23 with valvular incompetence) and 21 segments exhibited partial recanalization (19 with valvular incompetence). Superficial femoral vein segments were completely occluded in 19%, however, excellent collateralization was provided via the deep femoral vein. Thromboses of the posterior tibial vein demonstrated a high rate of recanalization with development of valvular incompetence in 52%. Whereas obstruction and valvular incompetence as single factors led to a postthrombotic leg in 8.5% and 33%, respectively, the most frequent cause for the development of the postthrombotic syndrome was the combination of reflux plus obstruction in the deep veins (50%). Compression therapy with elastic compression stockings is recommended for at least 5 years after the acute thrombosis.

Prospective 12-year follow-up study of clinical and hemodynamic sequelae after deep vein thrombosis in low-risk patients (Zürich study).

BACKGROUND: No prospective study of the long-term sequelae of more than 10 years after acute deep vein thrombosis exists so far. Therefore, 58 low-risk patients with DVT were included in a prospective study to evaluate the natural history of postthrombotic syndrome. METHODS AND RESULTS: Clinical and hemodynamic examinations were performed at the time of admission; after 3, 6, and 12 months; after the 2nd, 3rd, 4th, 5th years; and finally after the 12th year. All patients received heparin initially and oral anticoagulants subsequently. After 12 years, 64% of the patients exhibited normal findings. Mild skin changes were found in 28%, marked trophic changes in 5%, and only one venous ulcer occurred. Regular use of compression stockings was reported by 54% of the patients with multilevel thrombosis. Although mean maximum venous outflow was significantly reduced from the acute event to 12 years later (P<.003) compared with the contralateral leg, a significant (P<.05) improvement was observed 6 months later. Recanalization of calf vein thrombosis was detected by Doppler sonography after 3 months. Sixty-four percent of the multilevel thromboses were recanalized completely or in part after 1 year; in 69%, valvular incompetence was found. CONCLUSIONS: In contrast to earlier reports, this prospective study up to 12 years after deep vein thrombosis demonstrates a low incidence of postthrombotic syndrome by administration of oral anticoagulants and regular compression therapy. However, the adverse clinical event rate (mortality 14%) and a recurrence rate of 24% show that the prognosis after deep vein thrombosis does not appear favorable even in low-risk patients.

Effects of monoionic and nonionic radiographic contrast media on cutaneous microcirculation in patients with peripheral arterial occlusive disease.

The purpose of the study was to compare the in vivo effects of two low-osmolar radiographic contrast media, a monoionic (sodium/-meglumine ioxaglate, Hexabrix) and a non-ionic one (iopromide, Ultravist 300) on the cutaneous microcirculation in patients with peripheral arterial occlusive disease in a prospective randomised double-blind study. In 20 patients with peripheral arterial occlusive disease scheduled for percutaneous transluminal angioplasty skin microcirculation was assessed by laser Doppler fluxmetry and transcutaneous oxygen tension measurements at the foot dorsum for continuous recordings of the cutaneous microvascular perfusion and skin oxygenation. Before angioplasty 10 ml nondiluted contrast medium was injected intraarterially and the acute effect on transcutaneous oxygen tension and laser Doppler flux was registered. Mean laser Doppler flux and oxygen tension were evaluated initially, after arterial puncture and after contrast medium injection. In addition, flux motion was analysed with respect to frequency and amplitudes changes. No significant changes in laser Doppler flux and fluxmotion patterns were found between both groups after contrast medium injection. However, mean transcutaneous oxygen tension of the patients receiving monoionic ioxaglate dropped significantly (P = 0.01). The differences of both contrast media on red blood cell aggregation shown in vitro do not correlate to intravital microcirculatory measurements in patients with arterial occlusive disease of the lower limb. Microvascular skin blood flow and flux motion at the foot in these patients do not change significantly after intraarterial injection of ioxaglate and iopromide. However, oxygen supply of the skin is transient impaired after interarterial injection of the anionic contrast agent ioxaglate, which was not associated with clinical symptoms.

[Double-blind study of the effect of dipyridamole in patients with intermittent claudication]. / Doppelblindstudie zur Wirkung von Dipyridamol bei Patienten mit Claudicatio Intermittens.

32 patients (mean age 65 years, range 51-75 years) were included in this controlled, double blind study to evaluate the effect of dipyridamole in patients with intermittent claudication. Following a run-in phase of one month, 15 patients received 400 mg dipyridamole per day and 17 patients placebo. Patient characteristics (risk factors, age, clinical and apparative tests) of both groups did not differ significantly before and during the study period. Mean pain free und absolute walking distance on the treadmill (3.2 km/h, 12.5 degrees gradient) increased significantly in both groups during study period (p < 0.001 and p < 0.01). Explanations are more intensive physical activity and increasing adaptation to treadmill exercise. However, dipyridamole did not induce a significantly longer walking distance in comparison with placebo. The working hypothesis that the drug with inhibiting properties of thrombocyte function prolongs walking distance in intermittent claudication, could not be confirmed.