Experimental evaluation of the mechanical strength of stapling techniques

Background: The single stapling technique (SST) and the double stapling technique (DST) are common anastomoses for rectal cancer. Although many mechanical devices have been developed, the best choice remains unclear. In this study we examined the strength of anastomoses by determining their bursting pressures using an animal model. Methods: The intestines of pigs were used. In experiment 1, we compared the bursting pressures for Endo GIA (TM) 60 blue, Endo GIA (TM) 60 green, and GIA (TM) 60 blue. In experiment 2, the bursting pressures of a buttressed cutting site and a nonbuttressed cutting site were measured. In experiment 3, the SST, DST, and DST with buttress using PCEEA (TM) were performed and the bursting pressures and points of these anastomoses were examined. Results: The bursting pressure of Endo GIA 60 blue (80.3 +/- 10.5mmHg) was significantly higher than that of Endo GIA 60 green (37.3 +/- 4.2mmHg) and GIA 60 blue (31.7 +/- 5.8 mmHg) (p < 0.01). When a cut end was buttressed, the bursting pressure (149.6 +/- 37.6 mmHg) was significantly higher than that of the nonbuttressed end (75.3 +/- 25.1 mmHg) (p < 0.01). The bursting pressure among SST, DST, and DST with buttress was not significantly different. Only one bursting point was the crossing point of the PCEEA and Endo GIA and the bursting pressure of this point was much lower than that of the others. Conclusion: Endo GIA was most suitable for DST. The SST, DST, and DST with buttress had almost the same strength. The crossing point of PCEEA and Endo GIA may be a dangerous point for DST.