S. Rosfors et A. Noren, Venous haemodynamics and morphology in relation to recanalisation and thrombus resolution in patients with proximal deep venous thrombosis, PHLEBOLOGY, 14(1), 1999, pp. 33-38
Objective: Follow-up studies of deep venous thrombosis (DVT) are needed to
gain increased knowledge of the process of recanalisation over time. In thi
s study modern diagnostic techniques were used to analyse changes in venous
circulation during the process of recanalisation and thrombus resolution.
Design and setting: Prospective follow-up study of patients with symptomati
c DVT referred to a vascular diagnostic laboratory. The patients were evalu
ated by repeated examinations with colour duplex ultrasound and computerise
d strain-gauge plethysmography.
Patients: Eighteen consecutive patients with acute DVT occluding the calf v
eins and femoro-popliteal vein segments.
Main outcome measures: Ultrasonographic assessment of thrombus resolution a
nd flow patterns in deep and superficial veins. Plethysmographic determinat
ion of venous volume and venous outflow capacity.
Results: At 3 months' and 6 months' follow-up, 33% and 56%, respectively, w
ere recanalised but almost all limbs still had some degree of functional ou
tflow obstruction. Duplex evaluation further demonstrated a complex pattern
of recanalisation with thrombus resolution from above, from below or both.
Computerised strain-gauge plethysmography showed a progressive time-relate
d increase in venous outflow capacity and venous volume over 6 months, but
volumetric variables could not be used to distinguish between limbs with pa
tent veins and those with still-occluded veins. None of the limbs had compl
etely compressible femoro-popliteal venous segments at the end of the follo
w-up.
Conclusion: The combination of these two modern diagnostic techniques, suit
able for repeated studies, can provide detailed information on morphologica
l and haemodynamic changes occurring during the process of recanalisation a
nd thrombus resolution.