Influence of Robot-Assisted Partial Nephrectomy on Long-Term Renal Function as Assessed Using 99m-Tc DTPA Renal Scintigraphy

Background: The long-term split renal function after robot-assisted partial nephrectomy (RAPN) is yet to be elucidated. This study aimed to assess long-term renal function of RAPN, using renal scintigraphy, and to identify clinical factors related to deterioration of renal function on the affected side of the kidney. Patients and Methods: RAPN for small tumors was performed, and split renal function was evaluated using 99m-Tc DTPA renal scintigraphy before and 1 year after surgery. Clinical factors (age, gender, body mass index, tumor side, presence of urinary protein, diabetes, hypertension, and dyslipidemia), perioperative factors (renal nephrectomy score [RNS], tumor diameter, overall surgery duration, console time, warm ischemic time, and amount of bleeding), and renal function (estimated glomerular filtration rate [eGFR] and glomerular filtration rate [GFR] measured using scintigraphy on both the affected and contralateral kidneys) were analyzed. Results: Sixty-six patients were included in the study. The median eGFR decreased from 71.9 to 63.9 mL/min after 1 year (p < 0.001), accounting for a mean loss of 10.1%. In scintigraphy examination, the median GFR on the affected kidney side decreased from 41.1 to 33.7 mL/min after 1 year (p < 0.001), accounting for a mean loss of 16.8%. RNS was significantly associated with renal function. Among RNS factors, the N factor is associated with renal function after RAPN. Conclusion: RNS, particularly the N factor, possibly influences the long-term deterioration of renal function after RAPN.