Precision of suture placement with microscope- and loupe-assisted anastomoses

Twenty-eight anastomoses involving seven surgeons were done on 2 mm Gortex vascular prostheses to test the effect of magnification on the precision of suture placement. One-half were done with 3.5-4x prism loupe magnification and the other one-half with 8-30x microscope magnification. The variability of suture placement (defined here as precision) was measured in a blinded fashion. The mean suture puncture to prosthesis edge measurement for the microscope-assisted group was approximately 0.03 mm closer to the edge. The variability from the mean for the microscope-assisted group was approximately 0.01 mm less than that for the loupe-assisted group. This difference was statistically significant at a P value of 0.0123.