Applied anatomy of pelvic lymph nodes and its clinical significance for prostate cancer:a single-center cadaveric study

BACKGROUND: Pelvic lymph node dissection (PLND) is one of the most important steps in radical prostatectomy (RP). Not only can PLND provide accurate clinical staging to guide treatment after prostatectomy but PLND can also improve the prognosis of patients by eradicating micro-metastases. However, reports of the number of pelvic lymph nodes have generally come from incomplete dissection during surgery, there is no anatomic study that assesses the number and variability of lymph nodes. Our objective is to assess the utility of adopting the lymph node count as a metric of surgical quality for the extent of lymph node dissection during RP for prostate cancer by conducting a dissection study of pelvic lymph nodes in adult male cadavers. METHODS: All 30 adult male cadavers underwent pelvic lymph node dissection (PLND), and the lymph nodes in each of the 9 dissection zones were enumerated and analyzed. RESULTS: A total of 1267 lymph nodes were obtained. The number of lymph nodes obtained by limited PLND was 4–22 (14.1 ± 4.5), the number obtained by standard PLND was 16–35 (25.9 ± 5.6), the number obtained by extended PLND was 17–44 (30.0 ± 7.0), and the number obtained by super-extended PLDN was 24–60 (42.2 ± 9.7). CONCLUSIONS: There are substantial inter-individual differences in the number of lymph nodes in the pelvic cavity. These results have demonstrated the rationality and feasibility of adopting lymph node count as a surrogate for evaluating the utility of PLND in radical prostatectomy, but these results need to be further explored.