Effects of methylene blue, indigo carmine solution and autologous erythrocyte suspension on formation of adhesions after injection into rats

The aim of this study was to determine whether autologous erythrocyte suspe nsion can be used as a dye for evaluation of tubal patency and whether it h as any advantages over methylene blue or indigo carmine solutions. Reproduc tively healthy female nulliparous Wistar Albino rats (n = 30), aged 6 month s, mass 165-195 g, were assigned randomly to three groups. Rats received a 1 mi i.p. injection of 5% (w/v) methylene blue solution (methylene blue gro up: n = 10), 5% (w/v) indigo carmine solution (indigo carmine group: n = 10 ) or 5% (v/v) fresh autologous erythrocyte suspension (autologous erythrocy te group: n=10). At 4 weeks after injection, a small sterile opening was ma de in the peritoneal cavity of each rat. The cavity was rinsed once with TC M-199 to collect macrophages. The rinsed peritoneal contents were cultured overnight to evaluate macrophage activation. The peritoneal opening was exp anded for evaluation of adhesion formation. Only one rat from the autologou s erythrocyte group had intra-peritoneal adhesions (score 2), whereas all r ats in the methylene blue group (score 1: n = 1; score 2: n = 4; score 3: n = 4; and score 4: n = 1) and seven rats in the indigo carmine group (score 1: it = 1; score 2: n = 2; score 3: n = 3; and score 4: n = 1) had intra-a bdominal adhesions. Macrophage activity was observed in the cultured perito neal contents collected from the methylene blue and indigo carmine groups b ut not from the autologous erythrocyte group. Adhesion formation could be d ue to macrophage activation caused by methylene blue and indigo carmine sol utions. These results indicate that tubal patency can be observed by laparo scopy using autologous erythrocyte suspension The results of this study are believed to be the first to indicate that a patient's own erythrocyte susp ension could be used during observation of tubal patency by laparoscopy. Ho wever, further studies are required.