Partial Nephrectomy in Solitary Kidneys: Intraoperative Techniques and Their Impact on Chronic Kidney Disease Progression

Objective: Solitary kidney tumors are a challenging scenario necessitating both oncologic efficacy and renal function preservation. Partial nephrectomy (PN), when feasible, remains the gold standard for management. We examine intraoperative techniques and their association with renal function decline in patients with solitary kidneys undergoing PN. Methods: In two high volume academic referral centers, we analyzed patients that underwent PN in a solitary kidney from 2000 to 2023. Patient characteristics, tumor details, and operative details were obtained. Chronic kidney disease (CKD) upstaging from pre- to postoperative was the primary outcome, with multivariable analysis examining the association between intraoperative factors and CKD progression. Results: In total, 104 patients were included, of which 38 (36.5%) experienced CKD upstaging. Mean eGFR decline was 15.4% at median follow-up of 16 months. Cold ischemia was associated with higher odds of CKD upstaging compared to warm ischemia (OR 3.64; 95% CI 1.06–12.52) and no ischemia (4.55; 95% CI 1.09). Notably, cold ischemia cases tended to involve significantly larger, more complex tumors in patients with lower baseline renal function. Ischemia time, parenchyma resection, renal volume change, operative time, and renorrhaphy type were not predictors of CKD upstaging. Conclusions: PN in solitary kidneys remains standard with evidence of excellent renal preservation in this cohort. Worse outcomes were observed with cold ischemia, although this more likely represents underlying tumor complexity with other uncontrollable factors; however, this should be explored further. These findings suggest that renal functional outcomes are likely reasonable in patients with solitary kidneys undergoing PN when appropriate patient selection and sound surgical technique are utilized.