Reduction of abdominal wall blood flow by clamping or carbon dioxide insufflation increases tumor growth in the abdominal wall - An experimental study in rats

Background: We have previously demonstrated that there is a reduction of blood flow in the abdominal wall in rats insufflated with air concomitant with an increase in tumor growth. The present study was designed to examine whether a reduction of blood flow achieved by clamping or insufflation with carbon dioxide (CO2) would increase tumor growth in the abdominal wall. Methods: In the first part of the experiments, laser Doppler blood flow of both rectus muscles was measured in 16 Wistar Fu rats. The left rectus muscle was clamped to reduce blood flow, and 5 x 10(4) adenocarcinoma cells were injected into both rectus muscles. Clamping was maintained for 45 min. In the second part, 22 rats had 5 x 10(4) adenocarcinoma cells injected into the rectus muscle and blood flow was measured. The experimental group (n = 11) was insufflated with CO2 at 10 mmHg for 45 min; the control group (n = 11) was not insufflated. After 9 days, tumor weight and volume were analyzed. Results: Clamping caused a 69% reduction of blood flow (p < 0.001), whereas no reduction was registered on the nonclamped side. Tumor weight (p = 0.028) and volume (p = 0.030) were increased on the clamped side. The insufflation Of CO2 caused a 71% reduction of blood flow, whereas no reduction was registered in the control group. Tumor weight (p = 0.006) and volume (p = 0.006) were increased in the insufflated group. Conclusion: Clamping, as well as CO, insufflation, causes a significant reduction of blood flow in the abdominal wall. which seems to increase tumor growth at the same site.