Study of venous blood flow changes during laparoscopic surgery using a thermodilution technique

Abstract

<h4>Background</h4>Many modalities exist to analyse those factors that contribute to venous stasis and deep venous thrombosis (DVT) during laparoscopic surgery. To the authors' knowledge intraoperative measurement of femoral venous blood flow has not yet been performed nor has the influence of sequential compression devices been assessed using this parameter.<h4>Methods</h4>The thermodilution technique similar to that employed in cardiac output measurement was used to determine changes in blood flow in the right femoral vein during laparoscopic cholecystectomy. Deep venous thrombosis prophylaxis involved perioperative use of sequential compression devices and subcutaneous heparin 5000 U.<h4>Results</h4>Pneumoperitoneum and the Trendelenburg position reduced femoral venous return in four of the six patients studied, but sequential compression devices failed to return blood flow to baseline in a predictable fashion.<h4>Conclusions</h4>Although the measurement of blood flow using thermodilution is regarded as a reliable technique, during general anaesthesia the results may be susceptible to haemodynamic variations related to the anaesthetic agents as well as to the laparoscopic procedure. In addition sequential compression devices (when used alone) may not provide adequate prophylaxis against DVT because they do not predictably increase femoral blood flow.