Experimental study of peritoneal blood flow and insufflation pressure during laparoscopy

Background: Port-site metastases after laparoscopic surgery may occur with greater frequency than would be expected following open resection of intra-abdominal malignancies, but the causal mechanism for this is incompletely understood. The possibility that insufflation may increase peritoneal blood flow producing a wound environment conducive to the formation of metastases was investigated. Methods: The effects of insufflation gas type and pressure were studied in 30-kg female pigs. Pigs were divided into five groups, which were subjected to insufflation at 12 mmHg pressure with helium, insufflation at 12, 8 or 4 mmHg pressure with carbon dioxide, or laparotomy. A microsphere technique utilizing two distinct radiotracers, (99m) Tc-labelled macroaggregated albumin (MAA) and Cr-51-labelled MAA, was used to study blood flow to the peritoneum, liver and kidneys. Results: Insufflation with carbon dioxide or helium gases had no effect on renal (P < 0.09) or hepatic blood flow (P = 0.54). However, insufflation significantly increased peritoneal blood flow when carbon dioxide (P < 0.05), but not when helium (P = 0.99), was used as the insufflating gas. Conclusion: These data suggest that blood flow within the peritoneum is influenced by insufflation with carbon dioxide. It is conceivable that such hyperaemia could increase the propensity for implanted tumour cells to metastasize in these sites following laparoscopy.