Parenchymal volume analysis to assess longitudinal functional decline following partial nephrectomy

Area of Science:

• Nephrology
• Urology
• Surgical Oncology

Background:

• Partial nephrectomy (PN) is a standard treatment for renal tumors.
• Understanding factors influencing long-term kidney function after PN is crucial for patient management.
• Kidney function decline post-PN can be influenced by various patient and surgical factors.

Purpose of the Study:

• To identify factors associated with longitudinal ipsilateral functional decline after partial nephrectomy (PN).
• To analyze the impact of renal comorbidities and ischemia time on kidney function post-PN.
• To determine predictors of parenchymal atrophy and functional loss in the remaining kidney.

Main Methods:

• Retrospective analysis of 1140 patients undergoing PN between 2012-2014.
• Inclusion criteria required imaging and serum creatinine levels pre-PN, 1-12 months post-PN (new baseline), and >3 years later.
• Parenchymal-volume analysis for split renal function and multivariable regression to identify predictors of atrophy and functional decline.

Main Results:

• Median follow-up was 6.3 years; median ipsilateral parenchymal atrophy was 1.2 cm³/year, accounting for 53% of functional decline.
• Significant renal comorbidity, age, and warm ischemia were independently associated with parenchymal atrophy (P < 0.01).
• Significant renal comorbidity and ipsilateral parenchymal atrophy predicted annual ipsilateral functional decline (P < 0.01).

Conclusions:

• Longitudinal renal function following PN generally aligns with the natural aging process.
• Significant renal comorbidities, patient age, warm ischemia duration, and ipsilateral parenchymal atrophy are key predictors of functional decline post-PN.
• Managing comorbidities and minimizing ischemia are vital for preserving kidney function after partial nephrectomy.