Open versus minimally invasive cytoreductive nephrectomy (CN) for metastatic renal cell carcinoma (mRCC): Results from a multicenter retrospective study

Aim of the study: Recent evidence outlined that not all patients with mRCC might benefit from CN. However, there is lack of data on perioperative morbidity after this procedure. We aimed to investigate the impact of surgical approach on perioperative outcomes and surgical complications relying on a multicenter international registry. Materials and methods: Clinical data of 681 patients with mRCC undergoing CN at 11 centers included in the REgistry of MetAstatic RCC (REMARCC) from January 2014 to December 2017 were retrospectively collected. Patients with complete data on demographics and comorbidity profiles were included in final analysis. Study endpoints were: a) postoperative complications, assessed and graded using the modified Clavien-Dindo scale, and b) 30th day readmission rate. Results: Overall, 369 (54.2%) patients (247 open CN [OCN] and 122 minimally-invasive CN [MICN]) were considered. Patients treated with OCN had a significantly higher cT stage (p = 0.01), tumor size (p < 0.0001) and cN stage (p = 0.04). Conversely, there was no difference in terms of gender, age, Charlson comorbidity index, body mass index, site of metastasic lesions and baseline hemoglobin level, LDH level, glomerular filtration rate and calcemia. Lymph node dissection (LND) rate and renal vein/vena cava thrombectomy were significantly higher in the OCN compared to the MICN (p < 0.0001 and p = 0.001, respectively). Median estimated blood loss was significantly lower in the MICN compared to the OCN group (100 vs 450 cc, p < 0.0001). The rate of removal of adjacent organs beyond the tumorbearing kidney was not significantly different among the two groups. Patients with MICN compared to OCN had a significantly lower intraoperative (10% vs 22.6%, p = 0.004), overall postoperative (18% vs 38.6%, p < 0.0001) and major postoperative (2.5 vs 8.2%, p = 0.03) complications and lower median length of stay (5 vs 8 days, p < 0.0001). Perioperative mortality was reported in 3 patients in the OCN group. Readmission rate was 7.1% in both groups. Discussion: MICN was feasible and achieved acceptable perioperative morbidity in selected patients with mRCC. The main study limitation is the retrospective design with risk of selection and attrition bias.