Optimal port locations for endoscopic intracorporeal knotting

Abstract.

Port location is crucial for endoscopic manipulations. The aim of the study was to investigate the influence of manipulation, azimuth, and elevation angles of instruments on endoscopic intracorporeal knotting. The standard task was tying a surgeon's knot. Manipulation angles of 30°, 45°, 60°, 75°, and 90° with equal and unequal azimuth angles and elevation angles of 0°, 30°, and 60° were investigated. The endpoints were the execution time and parameters of knot analysis. The execution time was shorter with 60° than with either 90° or 30° manipulation angles (p < 0.0001 and p < 0.01). Equal azimuth angles resulted in a shorter execution time than wide unequal angles (p < 0.001). A combination of 60° manipulation angle with 60° elevation angle had the shortest execution time (p < 0.001) and highest performance quality score (p < 0.02). A range of 45°–75° manipulation angles with equal azimuth angles is recommended. As the manipulation angle increases, the elevation angle has to increase accordingly.