title: What is better in percutaneous nephrolithotomy - Prone or supine? A systematic review.
abstract: OBJECTIVE
  To review the literature reporting the technique of percutaneous nephrolithotomy (PCNL) and outcomes for prone and supine PCNL, as PCNL is an established treatment for renal calculi and both prone and supine PCNL have been described, but there has been much debate as to the optimal position for renal access in PCNL.
  
  
  METHODS
  A review of the medical literature was conducted using the PubMed database to identify relevant studies reporting on prone and supine PCNL published up until July 2015. Only publications in English were considered. Search terms included 'supine', 'prone', 'percutaneous nephrolithotomy', 'PCNL' and 'randomised controlled trial'. Articles relevant to the particular aspect of PCNL discussed were selected.
  
  
  RESULTS
  In all, 30 articles were included in the literature review. Nine of these articles were of Level 1 Evidence as graded by the Oxford System of Evidence-based Medicine.
  
  
  CONCLUSIONS
  The present systematic review highlights the benefits and disadvantages of supine and prone PCNL. The published data on supine and prone PCNL have shown no significant superiority of either approach. Whether prone or supine PCNL is optimal, remains a debatable topic.
authors.affiliation: University Hospitals of North Midlands NHS Trust, Stoke-on-Trent, UK.
authors.forename: David K-C
authors.initials: DK
authors.lastname: Mak
authors.affiliation: University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Smith
authors.affiliation: Sobeh's Vascular and Medical Center Dubai, UAE, Honorary Consultant Urologist Luton and Dunstable NHS Trust, UK.
authors.forename: Noor
authors.initials: N
authors.lastname: Buchholz
authors.affiliation: Imperial College Healthcare NHS Trust, London, UK.
authors.forename: Tamer
authors.initials: T
authors.lastname: El-Husseiny
keywords: PCNL; PCNL, percutaneous nephrolithotomy; Prone; RCT, randomised control trial; SFR, stone-free rate; Stones; Supine