Background and purpose: Functional losses near 20% are seen in the operated kidney during partial nephrectomy. Resected healthy margins are small and ischemia time limited in the modern era. We hypothesize that reconstruction following tumor resection is modifiable and a significant cause of renal function injury.
Materials and methods: A literature review of Medline and Scopus was performed for all available dates focusing on partial nephrectomy, renal function, and renal reconstruction. An additional review was performed evaluating recent advances in biomarkers of acute kidney injury.
Results: Serum creatinine is of limited value in measuring renal preservation during partial nephrectomy. Stimulated glomerular filtration rate can estimate renal reserve, but is more difficult to measure. CT-based three-dimensional measurements provide the ability to isolate ipsilateral functional loss. Newer urinary biomarkers of acute kidney injury such as kidney injury molecule-1 and cell cycle markers are emerging and might help to quantify renal function loss in real time. Most prior research has focused on ischemia and enucleation. However, despite minimizing both, significant renal function losses are still seen. Four retrospective controlled studies were found comparing cortical renorrhaphy to omission of cortical renorrhaphy. Three of the four found a statistical benefit to nonrenorrhaphy with the range of volume or functional loss in those three being 3.8% to 11.5% vs 15.6% to 20.4%. Urine leaks and bleeding complications were similar to reported rates for both groups.
Conclusion: Studies evaluating renal function preservation after partial nephrectomy should control for reconstructive injury in addition to ischemia time and resected healthy margin. Cortical renorrhaphy is associated with renal volume and functional loss on retrospective studies, which might be especially relevant in the setting of chronic kidney disease or solitary kidney. Newer biomarkers of renal injury should be used when studying predictors of renal injury.