Oncological and functional outcomes of patients who underwent open partial nephrectomy for kidney tumor

Objective: To report long-term functional and oncological outcomes of OPN Methods: We enrolled 182 patients who underwent consecutive OPN with a diagnosis of kidney tumor in our clinic between April 2002 and February 2020 and were selected from our prospective OPN database. Preoperative demographic and clinical characteristics, intraoperative and pathological results, and patients' postoperative functional and oncological follow-up data were retrospectively analyzed. Overall survival (OS) and disease- free survival (DFS) were evaluated using Kaplan-Meier survival analysis. The time-dependent variation between preoperative and postoperative functional results was statistically analyzed and presented in a graph. Results and limitations: The mean age was 54.4 ± 10.8 yr, and the median age-adjusted Charlson comorbidity index (ACCI) was 1 (interquartile range [IQR] 0-1). The mean tumor size was 3.1 ± 1.2 cm, and the median RENAL score was 6 (IQR 5-8). The most common malign histopathological subtype was clear cell carcinoma with 76.6%, and five cases (3.4%) had positive surgical margins (PSMs). The most common surgical techniques were the retroperitoneal approach (98.9%) and cold ischemia (88.5%). Estimated glomerular filtration rate (eGFR) preservation was 92% (80.8-99.3, IQR), which translates to 32% chronic kidney disease (CKD) upstaging. Acute kidney injury (AKI) was detected in 27 (14.8%) patients according to RIFLE criteria. The intraoperative complication rate was 5.5%, and the postoperative overall complication rate (Clavien-Dindo 1-5) was 30.2%. Major complications (Clavien-Dindo 3-5) were observed in 13 (7.1%) patients. The median oncological follow-up was 42 mo (21.3- 84.6, IQR), and the 5- and 10-yr OS were 90.1% and 78.6%, 5 and 10-yr DFS were 99.4% and 92.1%, respectively. No local recurrence was observed in 5 (3.4%) patients with PSMs; only one had distant metastasis in the 8th postoperative month. The retrospective design, the small number of patients who underwent PN based on mandatory indication, and one type of surgical approach may limit the generalizability of our findings. Conclusions: This study confirms excellent long-term oncologic and functional outcomes after OPN in a cohort of patients selected from a single institution. In light of the information provided by the literature and our study, our recommendation is to push the limits of PN under every technically feasible condition in the treatment of kidney tumors to protect the kidney reserve and achieve near-perfect oncological results.