Objective: To evaluate a non-invasive and selective measurement of in vivo venous compliance of the human saphenous vein using sonography. Design: An experimental study in patients prior to coronary bypass surgery. Setting: Departments of Physiology and Cardiothoracic Surgery, University Hospital of Angers. Patients: Thirty patients investigated prior to coronary bypass surgery. Interventions: Simultaneous strain-gauge venous occlusion plethysmography (VOP) and measurements of the circumference of the great saphenous vein by sonography at four different occlusion pressures: 20, 30, 40 and 50 mmHg. In 10 of the same patients, in vitro determination of pressure–volume relationship during progressive inflation of excised saphenous vein samples. Main outcome measures: 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 individual 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 measurement of in vivo venous compliance, although the measured compliances differ from other techniques.
Expression of apoptosis in human saphenous vein grafts in restoration of blood flow through coronary bypass surgery