title: Kidney access device.
abstract: BACKGROUND
  Percutaneous nephrolithotomy is the most complicated stone surgery technique to learn. The steep learning curve is related mainly to obtaining precise renal access by puncturing the targeted calyx. A minimally misaligned puncture may lead to torrential bleeding, failure of the surgery, and complications. Renal puncture can take a long time, and the increased fluoroscopic time is a hazard for the patient and surgeon.
  
  
  METHODS
  To aid in renal puncture and overcome the learning curve associated with learning the renal puncture technique, we designed a kidney access device (KAD), which helps align the 3-dimensional targeted calyx under fluoroscopy for precise needle placement. The KAD allows access to calyces at all angles. A 3-step puncture technique was formulated for puncturing the kidney using the KAD in a porcine model (with comparable renal size and anatomy with humans). To evaluate the practicality of the KAD and its possible advantages and limitations, the KAD was used to puncture 3 targeted calyces of bilateral kidneys in 4 pigs. Guidewires were inserted into the renal collecting system through the placed needle.
  
  
  RESULTS
  Mean time per puncture was 4 ± 2 minutes (n = 24). Necropsy showed no retroperitoneal hematoma, visceral organ injury, or active bleeding from kidneys in any of the pigs. Kidneys were dissected and precise intrarenal placements of guidewires in relation to targeted calyces were noted at all 24 sites.
  
  
  CONCLUSIONS
  The KAD with the 3-step technique aids in the safe and accurate renal puncture, even in novice hands, while drastically reducing operative and fluoroscopy time. The KAD may also be used to access other organs and has potential applications in minimally invasive surgery.
authors.affiliation: Department of Surgery.
authors.forename: Jasneet
authors.initials: J
authors.lastname: Singh Bhullar
authors.affiliation: Department of Biomedical Engineering, Providence Hospital & Medical Centers, Southfield, Michigan.
authors.forename: Robert
authors.initials: R
authors.lastname: Scott
authors.affiliation: Department of Surgery.
authors.forename: Mitesh
authors.initials: M
authors.lastname: Patel
authors.affiliation: Department of Surgery.
authors.forename: Vijay K
authors.initials: VK
authors.lastname: Mittal
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004867:Equipment Design; D005471:Fluoroscopy; D007669:Kidney Calculi / Q000000981:diagnostic imaging / Q000628:therapy*; D007670:Kidney Calices / Q000601:surgery*; D009403:Nephrostomy, Percutaneous / Q000295:instrumentation*; D013552:Swine
keywords: Kidney puncture; Kidney puncture device; PCNL; Percutaneous nephrolithotomy; Renal puncture