title: Comparison of a novel one-step percutaneous nephrolithotomy sheath with a standard two-step device.
abstract: OBJECTIVE
  Percutaneous nephrolithotomy (PCNL) is the treatment of choice for large renal calculi. The most widely used access sheath for PCNL involves two steps including placement of a high-pressure balloon catheter (HPBC) followed by advancement of a sheath over the balloon. A novel PCNL balloon/sheath combination (NSS) has been developed that allows for both dilation and sheath placement in a single step. The objective of this study was to compare the safety and efficacy of the NSS to the HPBC in a porcine model.
  
  
  METHODS
  Six farm pigs underwent placement of a standard HPBC in one kidney and the NSS on the contralateral side. We obtained access in the upper pole in 2 animals, middle pole in 2 animals, and lower pole in 2 animals. We obtained data on insertion time, difficulty of insertion, estimated blood loss (EBL), ability to visualize the collecting system, and gross and histopathologic analysis.
  
  
  RESULTS
  There was no statistical difference in degree of difficulty in placing the NSS (3 easy, 3 moderate) versus HPBC device (1 easy, 5 moderate; P = 0.07), estimated blood loss (P = 0.10), or the ability to visualize the collecting system (P = 0.32). There was a significantly shorter insertion time in the NSS group compared with the HPBC group (1:37 versus 2:26 minutes, P = 0.04).
  
  
  CONCLUSIONS
  This study demonstrates that the NSS is safe and effective in the porcine model. Trials in patients are currently under way.
authors.affiliation: Division of Urology, Loma Linda University School of Medicine, Loma Linda, California 92354, USA.
authors.forename: Lincoln J
authors.initials: LJ
authors.lastname: Maynes
authors.forename: Premal J
authors.initials: PJ
authors.lastname: Desai
authors.forename: Craig W
authors.initials: CW
authors.lastname: Zuppan
authors.forename: Brent J
authors.initials: BJ
authors.lastname: Barker
authors.forename: Grenith J
authors.initials: GJ
authors.lastname: Zimmerman
authors.forename: D Duane
authors.initials: DD
authors.lastname: Baldwin
mesh_terms: D000818:Animals; D002404:Catheterization; D004867:Equipment Design; D005260:Female; D009403:Nephrostomy, Percutaneous / Q000295:instrumentation* / Q000379:methods*; D013552:Swine