Comparing Outcomes of Robotic and Open Inguinal Lymph Node Dissection in Patients with Carcinoma of the Penis.

PURPOSE: We compared outcomes between robot-assisted video endoscopic inguinal lymphadenectomy and open inguinal lymph node dissection in patients without bulky nodal metastasis in a tandem contemporary cohort. MATERIALS AND METHODS: We retrospectively analyzed a prospectively maintained hospital registry of 51 patients who underwent robot-assisted video endoscopic inguinal lymphadenectomy and 100 treated with open inguinal lymph node dissection from 2012 to 2016 for groins without bulky nodal metastasis and who had a minimum 9-month followup. Complications were graded by the Clavien-Dindo classification, and nodal yield and disease recurrence during followup were assessed. Elastic net regression was used to select variables associated with major complications (Clavien 3a or greater) for multivariable analysis of plausible factors, including patient age, diabetes, body mass index, smoking, nodal stage, surgery type, sartorius transposition, saphenous vein transection and adjuvant radiotherapy. Penalized likelihood logistic regression methods were used for multivariate analysis to ascertain final effect sizes while accounting for sparse data bias. RESULTS: Robot-assisted video endoscopic inguinal lymphadenectomy and open inguinal lymph node dissection had comparable median lymph node yields (13 vs 12.5). No patient experienced recurrence during the median followup of 40 months. Robot-assisted video endoscopic inguinal lymphadenectomy was associated with significantly lower hospital stay, days needing a drain in situ, incidence of major complications, edge necrosis, flap necrosis and severe limb edema. On multivariable analysis pathological nodal stage (OR 2.8, 95% CI 1.1-6.8, p = 0.027) and open inguinal lymph node dissection (OR 7.5, 95% CI 1.3-43, p = 0.024) emerged as independent risk factors associated with an increased risk of major complications. CONCLUSIONS: Robot-assisted video endoscopic inguinal lymphadenectomy is a feasible technique which allows for a similar nodal yield while being associated with lower morbidity than open inguinal lymph node dissection in patients without bulky groin adenopathy.