How Might the Number of Lymph Nodes Removed during RARP Impact the Postoperative Outcomes?

Introduction: Symptomatic lymphocele remains a relevant complication after pelvic tumor surgery. This study aims to investigate how the number of lymph nodes removed may influence postoperative outcomes and if it increases the probability of detecting lymph node metastasis.

Methods: The study included 500 patients who underwent RARP including lymphadenectomy performed by a single surgeon. Patients were divided into two groups: group 1 consisted of 308 patients with 20 or fewer lymph nodes removed (mean 15), while group 2 had 192 patients with over 20 nodes removed (mean 27). Perioperative data were analyzed, and postoperative outcomes were compared between groups.

Results: Overall, lymph node metastasis was detected in 17.8% of men. In detail, out of 19.6 lymph nodes removed, an average of 3.14 lymph nodes per patient showed metastasis, with a slightly higher incidence of 19.7% in group 2 compared to 16.5% in group 1, though not statistically significant (p = 0.175). The number of lymph node metastases was significantly higher in group 2 patients (3.47) versus group 1 (2.37) (p = 0.048). All complications except symptomatic lymphoceles (p = 0.004) were not significantly different between groups. Univariate linear regression analysis revealed no correlation between the number of removed lymph nodes and symptomatic lymphocele. However, it did correlate with catheter days and readmissions.

Conclusion: A correlation may exist between the number of lymph nodes removed during RARP and an increased incidence of complications, particularly symptomatic lymphocele. A more extensive PLND may result in prolonged catheter days and increased readmissions. With the increased extent of pelvic lymphadenectomy, the probability of detecting lymphogenic metastasis rises. The diagnostic value of PLND is well established. Further randomized trials are needed to weigh its necessity and extent.