Background: Cytokine levels in the serum, blood and tissue may be predictive of the degree of stress perceived by patients undergoing major abdominal surgery and may impact cancer related outcomes. Inflammatory response to trauma includes IL-1b, IL-6, and TNFa in varying levels. Furthermore, alterations in circulating proteins VEGF and PDGF could directly stimulate tumor growth in cancer patients. We hypothesize the surgery-related differences in IL-6, and TNF-α will correlate with the degree of surgical trauma. Therefore, this study will compare the differences in cytokine/protein levels between patients undergoing hand-assisted laparoscopy, laparoscopy, and laparotomy.
Methods: Patients presenting to a private practice for colon resection were included as possible participants. Because the majority of immunologic alterations that occur following major surgery are not diagnosis related, this study includes patients with both benign and malignant conditions. Specific exclusion diagnoses included active acute diverticulitis, inflammatory bowel disease and hematologic disorders. Blood draws were performed in pre-operative holding and post-operative times of 4 hours, 24 hours, and 48 hours. Serum was evaluated for levels of IL-6, IL-1β, TNF-α, VEGF and PDGF-A using standard ELISA procedures and analyzed by ANOVA 2-way statistical analysis.
Results: Data evaluates ten open, nine hand assist and seven laparoscopic cases. In all three surgical techniques, serum levels of IL-6 are significantly different between the pre-operative time point and 4 hours post surgery (p=0.07). At 4 hours post surgery the TNF-α levels are lower in the laparoscopic patients as compared to those who received hand-assisted or open surgery. There is no change in the post-operative trend of IL-1β in all three surgical techniques. The VEGF serum levels significantly decreased 48 hours post surgery only in laparoscopic patients (p=0.007). Interestingly, serum levels of PDGF-A are increased at 4 hours post surgery in patients undergoing open surgery when compared to both minimally invasive techniques.
Conclusion: The data suggest an immunological benefit to patients undergoing laparoscopic large bowel resection as compared to laparotomy. There is a trend toward similar benefits in hand-assisted laparoscopy. Clearly, these results warrant more investigation as we continue to accrue patients for all three surgical techniques.