Alterations in peritoneal blood flow due to insufflation: a mechanism implicated in the aetiology of port site metastases?

Full text: It has been suggested that port site metastases might occur with greater frequency than would be expected following open resection of intra-abdominal malignancies, however the causal mechanism for this is incompletely understood. We investigated the possibility that insufflation may increase peritoneal blood flow producing a wound environment conducive to the formation of metastases. The effects of insufflation gases carbon dioxide and helium over the pressure range 0 to 12 mmHg were studied in a porcine model of laproscopic surgery. Organ blood flows were measured after employing a simultaneous dual isotope technique. 99MTc-macroaggregated albumin (MAA) was the radiotracer used representing the baseline condition and 51Cr-MAA was also administered representing the gas type/pressure intervention 30 minutes after laparotomy or pneumoperitoneum. The peritoneum, kidneys, liver and blood samples were removed and counted on two occasions: after 24 hours for 99MTc and at 6 days for 51Cr. The counts per organ relative to blood counts were used to calculate organ blood flows as a function of time. Results showed that insufflation with either carbon dioxide or helium gas had no effect on renal or hepatic blood flow at these pressures. However, insufflation with carbon dioxide but not with helium, significantly increased peritoneal blood flow, suggesting that the former gas may increase the propensity for implanted tumour cells to metastasise in port sites. Copyright (2003) The Australian and New Zealand Society of Nuclear Medicine Inc