Hemodynamic changes in the inferior caval vein during pneumoperitoneum

Background: Laparoscopic procedures of increasing difficulty and duration are becoming more and more common. This may cause significant challenges to the circulatory system and possibly influence thrombogenicity. Methods: Experimental study of carbon dioxide pneumoperitoneum in pigs. Results: Inferior caval vein blood flow remained unchanged, whereas inferior caval vein pressure increased during pneumoperitoneum. Inferior caval vein, pulmonary, and systemic vascular resistance increased during pneumoperitoneum and remained increased after exsufflation. Conclusions: Pneumoperitoneum leads to an increased inferior caval vein pressure, which could cause a dilation of peripheral veins. The similar patterns of vascular resistance in the inferior caval vein, pulmonary artery, and systemic arteries (a gradual increase remaining elevated after exsufflation) suggest a common humoral factor or increased sympathetic nerve activity. Received: 2 April 1996/Accepted: 7 June 1996