Tumors in Solitary Kidneys Are Not All Equal: Outcomes of Partial Nephrectomy in High-Risk Cases

Abstract

Introduction: While partial nephrectomy remains the preferred treatment of tumors in solitary kidneys, there is a broad range of complexity to these cases. This retrospective study refines our understanding of renal and oncologic outcomes in high-risk cases of partial nephrectomy of the solitary kidney (PNSK).

Methods: Review of our institutional database identified patients who underwent PNSK between 1990 and 2020. Cases were classified as high-risk PNSK based on having any of the following: clinical stage ≥ T3, RENAL (for radius, exophytic/endophytic, nearness of tumor to collecting system, anterior/posterior, location relative to polar line) nephrometry score ≥ 10, or multiple tumors suspicious for malignancies.

Results: Of the 124 cases included, 73 were classified as high-risk PNSK. The rate of high-grade perioperative complications was 32% among high-risk cases, compared with 12% among low-risk cases. The high-risk group recovered less of their baseline renal function compared with the low-risk group, although this gap narrowed with time, and the respective 5-year end-stage renal disease-free survivals were 89% and 100%. Baseline renal function, multifocal tumors, and intraoperative blood loss were predictors of long-term renal function. The 5-year local recurrence-free survival, cancer-specific survival, and overall survival rates in the high-risk group were 83%, 80%, and 77%, respectively.

Conclusions: Outcomes of PNSK remain preferrable to end-stage renal disease in the highest-risk patients. Keys to optimization are meticulous preservation of normal parenchyma and a bloodless field. Longer ischemia time is tolerable to achieve these goals, although it may benefit from the application of renal hypothermia.

Keywords: nephrectomy; renal cell carcinoma; renal neoplasms; solitary kidney.