The effect of body characteristics on mean operative times while experiencing the learning curve for robotic prostatectomy.

We reviewed our series of robotic-assisted radical prostatectomy to assess the effect of certain patient body characteristics on the mean operative time over the course of a single surgeon's learning curve. The operating room times were recorded for the first 210 cases performed. These cases were broken down into thirds and then patient characteristics were stratified by height, weight, body mass index (BMI) and final prostate volume. Mean body characteristics were equal for all groups. The average time for the first group (70 cases) was 157.9 min, the second group 148.5 min and the third 135.0 min. Times were significantly shorter for the patients <72 in. in height in the first 70 cases (168 vs. 153 min, P < 0.003). Cases were shorter in the first 70 for weight <200 lbs (142 vs. 173 min, P < 0.001). Patients with a BMI of 25-30 had a significantly shorter time (153 min) than those <25 (163 min, P < 0.02) and those >30 (164 min, P < 0.006). With regard to prostate volume, there was a significant shorter operative time for those patients with glands <60 g in the first group. Patients <72 in., <200 lbs, with a BMI of between 25 and 30, and prostate size <60 g had significantly shorter operative times in the first 70 cases of a single surgeon's learning curve.