title: Renal Ischemia and Function After Partial Nephrectomy: A Collaborative Review of the Literature.
abstract: BACKGROUND
  Partial nephrectomy (PN) is the current gold standard treatment for small localized renal tumors.; however, the impact of duration and type of intraoperative ischemia on renal function (RF) after PN is a subject of significant debate.
  
  
  OBJECTIVE
  To review the current evidence on the relationship of intraoperative ischemia and RF after PN.
  
  
  METHODS
  A review of English-language publications on renal ischemia and RF after PN was performed from 2005 to 2014 using the Medline, Embase, and Web of Science databases. Ninety-one articles were selected with the consensus of all authors and analyzed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria.
  
  
  RESULTS
  The vast majority of reviewed studies were retrospective, nonrandomized observations. Based on the current literature, RF recovery after PN is strongly associated with preoperative RF and the amount of healthy kidney parenchyma preserved. Warm ischemia time (WIT) is modifiable and prolonged warm ischemia is significantly associated with adverse postoperative RF. Available data suggest a benefit of keeping WIT <25min, although the level of evidence to support this threshold is limited. Cold ischemia safely facilitates longer durations of ischemia. Surgical techniques that minimize or avoid global ischemia may be associated with improved RF outcomes.
  
  
  CONCLUSIONS
  Although RF recovery after PN is strongly associated with quality and quantity of preserved kidney, efforts should be made to limit prolonged WIT. Cold ischemia should be preferred when longer ischemia is expected, especially in presence of imperative indications for PN. Additional research with higher levels of evidence is needed to clarify the optimal use of renal ischemia during PN.
  
  
  RESULTS
  In this review of the literature, we looked at predictors of renal function after surgical resection of renal tumors. There is a strong association between the quality and quantity of renal tissue that is preserved after surgery and long-term renal function. The time of interruption of renal blood flow during surgery is an important, modifiable predictor of postoperative renal function.
authors.affiliation: Division of Urology, Department of Translational Medicine, University of Eastern Piedmont, Maggiore della Carità Hospital, Novara, Italy. Electronic address: alessandro.volpe@med.unipmn.it.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Volpe
authors.affiliation: Department of Urology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Blute
authors.affiliation: Division of Urology, Department of Experimental and Clinical Medical Sciences, University of Udine, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Ficarra
authors.affiliation: Catherine and Joseph Aresty Department of Urology, USC Institute of Urology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
authors.forename: Inderbir S
authors.initials: IS
authors.lastname: Gill
authors.affiliation: Division of Urologic Oncology, Department of Surgical Oncology, Fox Chase Cancer Center, Philadelphia, PA, USA.
authors.forename: Alexander
authors.initials: A
authors.lastname: Kutikov
authors.affiliation: Division of Urology, Department of Oncology, University of Turin, San Luigi Hospital, Orbassano, Turin, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Porpiglia
authors.affiliation: Vattikuti Urology Institute, Henry Ford Hospital, Detroit, MI, USA.
authors.forename: Craig
authors.initials: C
authors.lastname: Rogers
authors.affiliation: Urology Service, Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.
authors.forename: Karim A
authors.initials: KA
authors.lastname: Touijer
authors.affiliation: Department of Urology, Leuven Cancer Institute, Universitair Ziekenhuis Gasthuisberg, Leuven, Belgium.
authors.forename: Hendrik
authors.initials: H
authors.lastname: Van Poppel
authors.affiliation: Department of Urology, Mayo Clinic, Rochester, MN, USA.
authors.forename: R Houston
authors.initials: RH
authors.lastname: Thompson
mesh_terms: D002292:Carcinoma, Renal Cell / Q000601:surgery*; D050377:Cold Ischemia / Q000706:statistics & numerical data*; D006801:Humans; D007680:Kidney Neoplasms / Q000601:surgery*; D009392:Nephrectomy / Q000379:methods*; D009399:Nephrons; D059351:Organ Sparing Treatments; D011183:Postoperative Complications / Q000453:epidemiology*; D051437:Renal Insufficiency / Q000453:epidemiology*; D052096:Warm Ischemia / Q000706:statistics & numerical data*
keywords: Ischemia; Nephron-sparing surgery; Partial nephrectomy; Renal cell carcinoma; Renal function