Learning curve of robotic-assisted microvascular anastomosis in the rat.

We hypothesized that the learning plateau and learning rate of robotic-assisted microvascular anastomosis could be estimated statistically using curve-fitting method. Three surgeons with various microsurgical experiences performed 20 microsurgical anastomoses of the rat femoral artery using the da Vinci robotic system (Intuitive Surgical, Inc., Sunnyvale, CA). We evaluated the anastomosis time, patency rate, and quality of anastomosis. Objective structured assessment of technical skills (OSATS) score which is introduced to assess surgical dexterity was also measured. The average starting anastomosis time was 101 ± 30 minutes, and the estimated mean learning plateau was 33 ± 15 minutes. The estimated mean learning rate for anastomosis time was 22 ± 5 trials and the estimated mean learning rate for OSATS score was 8 ± 1 trials. Overall patency rate was 90 ± 5%. Anastomosis patency correlated with OSATS score and quality of anastomosis rather than anastomosis time. Important aspects of learning curve can be estimated by fitting inverse curves for robotic-assisted microvascular anastomosis. As anastomosis time does not necessarily correlate with the patency rate, OSATS score might be a valuable tool to evaluate surgeons during training for this complicated surgical task.