Anatomic excision of anterior prostatic fat at radical prostatectomy: implications for pathologic upstaging

After exposure of the retropubic space, the surgeon commonly dissects the fat overlying the prostate and usually discards it. We have previously described the importance of dissecting this fat to completely visualize the dorsal venous complex (DVC) and prostatic apex. In this study, we describe a technique to dissect and remove the anterior prostatic fat pad (APF) and its anatomic and pathologic significance.

After the retropubic space was prepared, we dissected the fat overlying the puboprostatic ligaments and the DVC to fully expose these structures. The superficial branch of the DVC was then transected, and the fat was dissected cephalad to the junction with the bladder. The fat was then further dissected laterally toward the lateral pelvic sidewall. Video analysis of the lateral dissection of the fat revealed a direct link to the obturator lymph node chain, where it was transected. Pathologic analysis demonstrated that 30 (14.7%) of 204 patients had one or more APF lymph nodes, of which four were positive for metastatic prostate cancer. The cancer of 3 of these 4 patients was upstaged as a result of the detection of these positive nodes.

The dissection of the APF facilitates visualization of the apex and bladder neck. Anatomically, we have demonstrated that the APF contains lymph nodes approximately 15% of the time that are in communication with the obturator lymph node chain and DVC. We found that removal of the APF and its pathologic analysis can result in pathologic upstaging.