The Learning Curve of Robot-Assisted Radical Prostatectomy

PURPOSE: To evaluate the learning curve of a surgeon with no previous laparoscopy experience in performing robot-assisted radical prostatectomy (RARP). PATIENTS AND METHODS: A total of 120 patients with a 1-year follow-up after RARP were included to the study prospectively. Patients were grouped as the first, second, and third 40 patients. Surgical, oncologic, and functional outcomes were compared among groups. Analysis of variance, chi-square, and Kruskal-Wallis test were used for statistical analysis. RESULTS: All groups were similar with respect to age, prostate-specific antigen level, body mass index, Gleason score, and distribution of the clinical stage. The operative time was 182 minutes for group 1, 168 minutes for group 2, and 139 minutes for group 3 (P=0.01). Individual times of various stages of the procedure (dissection of the seminal vesicles, entering the extraperitoneal space and dissection of the endopelvic fascia, incision of the bladder neck, division of the prostatic pedicles and preservation of the neurovascular bundle, and urethrovesical anastomosis) decreased significantly over time. Estimated blood loss was 287 mL for group 1 238 mL for group 2, and 170 mL for group 3 (P=0.04). The length of stay was 5.1 days for group 1, 4.0 days for group 2, and 3.1 days for group 3 (P=0.005). Positive surgical margin rates were 22% (9) for group 1, 17% (7) for group 2, and 6% (2) for group 3 (P=0.03). While seven patients in group 1 and two patients in group 2 had biochemical recurrence, no patient in group 3 had biochemical recurrence (P=0.04). Continence rates at 12 months were 72.5%, 85%, and 92.5% in groups 1, 2, and 3, respectively (P=0.01). Potency rates at 12 months for groups 1, 2, and 3 were 60.5%, 66.7%, and 76.6%, respectively (P=0.03). CONCLUSION: Surgical, oncologic, and functional outcomes of RARP improve with increasing experience. Outcomes similar to the published series by high-volume centers could be achieved after 80 to 120 RARP cases.