IN-VIVO COMPLIANCE OF THE HUMAN SAPHENOUS-VEIN MEASURED BY SONOGRAPHY- COMPARISON WITH PLETHYSMOGRAPHIC AND IN-VITRO MEASUREMENTS

Objective: To evaluate a non-invasive and selective measurement of in vivo venous compliance of the human saphenous vein using sonography. D esign: An experimental study in patients prior to coronary bypass surg ery. Setting: Departments of Physiology and Cardiothoracic Surgery, Un iversity Hospital of Angers. Patients: Thirty patients investigated pr ior to coronary bypass surgery. Interventions: Simultaneous strain-gau ge venous occlusion plethysmography (VOP) and measurements of the circ umference of the great saphenous vein by sonography at four different occlusion pressures: 20, 30, 40 and 50 mmHg. In 10 of the same patient s, in vitro determination of pressure-volume relationship during progr essive inflation of excised saphenous vein samples. Main outcome measu res: Venous compliance obtained with the three methods. Results: Weak correlation coefficients were found between in vitro measurements and VOP (r=0.478, p<0.01) and sonography (r=0.497, p<0.02). Although indiv idual correlations between in vitro and VOP measurements ranged from 0 .928 to 0.999, a wide heterogeneity was found with sonography (from 0. 620 to 0.985). Conclusions: Sonography allows the selective measuremen t of in vivo venous compliance, although the measured compliances diff er from other techniques.