Standardized comparison of robot-assisted limited and extended pelvic lymphadenectomy for prostate cancer

Objectives To compare the perioperative course of patients undergoing robot-assisted limited lymph node dissection (LLND) or extended lymph node dissection (ELND) for prostate cancer. To examine the differential lymph node counts and rates of detection of lymph node metastases. Patients and Methods Between 2008 and 2012, 406 consecutive patients with D'Amico intermediate- or high-risk prostate cancer underwent either bilateral LLND (n = 204) or ELND (n = 202) and robot-assisted laparoscopic radical prostatectomy by a single surgeon. The region of dissection was the obturator fossa for LLND, while ELND included, in addition, the common iliac, external iliac and internal iliac lymph nodes. All complications within 90 days of surgery were recorded according to a modified Clavien system. Clinical variables were summarized and compared. Logistic regression was used to identify predictors of complications. Results There were no differences in demographics when comparing patients who underwent ELND with those who underwent LLND. The median operating time was 3.0h for the ELND cohort and 2.8h in the LLND cohort (P < 0.001). Intraoperative blood loss was 200mL in both cohorts. Hospital stay was longer for a small percentage of patients in the ELND cohort, with 75% of ELND patients and 85% of LLND patients staying 1 day (P = 0.004). No significant difference was found in the overall or major complication rates between LLND (21.6% overall; 6.9% major) and ELND (22.8% overall; 4.5% major). No difference was seen in the symptomatic lymphocele rate between LLND and ELND, 2.9 vs 2.5%, respectively. Overall, the lymph-node-positive rate was 12% compared with 4% for the ELND and LLND groups, respectively (P = 0.002). A higher Charlson comorbidity index score was associated with the development of major complications. Conclusions ELND at the time of robot-assisted radical prostatectomy can be performed safely with minimal additional morbidity. Long-term oncological and functional outcomes require further study.