The role of ischemia in the deterioration of renal function after partial nephrectomy

OBJECTIVES: Nephron-sparing surgery (NSS) has been considered throughout history for patients with solitary kidney, bilateral renal tumors, impaired renal function, and hereditary renal cancer. However, recently the indications for Partial Nephrectomy (PN) have extended and include patients with a healthy contralateral kidney. NSS has evolved in a great way during the last decade, specifically in terms of oncological indications, and in the renal ischemia time used with the goal to maintain as much renal function as possible. This change is secondary to a better understanding of renal cancer histology, the equivalence in oncological outcomes between radical and PN, and finally the impact of chronic kidney disease (CKD) as a cause of cardiovascular complications and mortality. The main purpose of our study is to review the role of ischemia in NSS. METHODS: A literature review was performed focusing on NSS, risk factors of renal damage, types of ischemia, as well as its effect on renal function, and ischemia time. CONCLUSIONS: Renal ischemia has been considered for a long time as the main factor related with postoperative Renal Function (RF) in patients with NSS. Furthermore it is one of the few modifiable factors that directly depend on the surgeon. The ischemia time limit, both in warm and cold, is not well established and is a controversial issue that is still on debate till now. At this moment, there is evidence that considers the impact of ischemia only in acute or early stages. Also other factors have emerged and seem to have greater effect on RF, mainly in the long-term, leaving ischemia in second place. These factors are the quantity and quality of the remaining renal parenchyma. More studies are needed to support this rising concept and to clarify the real part that ischemia plays.