title: Bench-Top Feasibility Testing of a Novel Percutaneous Renal Access Technique: The Laser Direct Alignment Radiation Reduction Technique (DARRT).
abstract: Traditional techniques for obtaining percutaneous renal access utilize continuous fluoroscopy. In an attempt to minimize radiation exposure, we describe a novel laser direct alignment radiation reduction technique (DARRT) for percutaneous access and test it in a bench-top model.
  
  
  
  In this randomized-controlled bench-top study, 20 medical personnel obtained renal accesses using both the conventional bullseye technique and the laser DARRT. The primary endpoint was total fluoroscopy time. Secondary endpoints included insertion time, puncture attempts, course corrections, and subjective procedural difficulty. In the laser DARRT, fluoroscopy was used with the C-arm positioned with the laser beam at a 30° angle. The access needle and hub were aligned with the laser beam. Effective caliceal puncture was confirmed with fluoroscopy and direct vision. The Paired samples Wilcoxon signed rank test was used for statistical analysis with significance at p < 0.05.
  
  
  
  A total of 120 needle placements were recorded. Fluoroscopy time for needle access using the laser DARRT was significantly lower than the bullseye technique in all groups as follows: attendings (7.09 vs 18.51 seconds; p < 0.001), residents (6.55 vs 13.93 seconds; p = 0.001), and medical students (6.69 vs 20.22 seconds; p < 0.001). Students rated the laser DARRT easier to use (2.56 vs 4.89; p < 0.001). No difference was seen in total access time, puncture attempts, or course corrections between techniques.
  
  
  
  The laser DARRT reduced fluoroscopy time by 63%, compared with the conventional bullseye technique. The least experienced users found the laser DARRT significantly easier to learn. This novel technique is promising and merits additional testing in animal and human models.
authors.affiliation: Department of Urology, Loma Linda University Health , Loma Linda, California.
authors.forename: Nazih
authors.initials: N
authors.lastname: Khater
authors.affiliation: Department of Urology, Loma Linda University Health , Loma Linda, California.
authors.forename: Jim
authors.initials: J
authors.lastname: Shen
authors.affiliation: Department of Urology, Loma Linda University Health , Loma Linda, California.
authors.forename: Javier
authors.initials: J
authors.lastname: Arenas
authors.affiliation: Department of Urology, Loma Linda University Health , Loma Linda, California.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Keheila
authors.affiliation: Department of Urology, Loma Linda University Health , Loma Linda, California.
authors.forename: Muhannad
authors.initials: M
authors.lastname: Alsyouf
authors.affiliation: Department of Urology, Loma Linda University Health , Loma Linda, California.
authors.forename: Jacob A
authors.initials: JA
authors.lastname: Martin
authors.affiliation: Department of Urology, Loma Linda University Health , Loma Linda, California.
authors.forename: Michelle A
authors.initials: MA
authors.lastname: Lightfoot
authors.affiliation: Department of Urology, Loma Linda University Health , Loma Linda, California.
authors.forename: Roger
authors.initials: R
authors.lastname: Li
authors.affiliation: Department of Urology, Loma Linda University Health , Loma Linda, California.
authors.forename: Gaudencio
authors.initials: G
authors.lastname: Olgin
authors.affiliation: Department of Urology, Loma Linda University Health , Loma Linda, California.
authors.forename: Jason C
authors.initials: JC
authors.lastname: Smith
authors.affiliation: Department of Urology, Loma Linda University Health , Loma Linda, California.
authors.forename: D Duane
authors.initials: DD
authors.lastname: Baldwin
mesh_terms: D000328:Adult; D005240:Feasibility Studies; D005471:Fluoroscopy / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D007396:Internship and Residency; D007668:Kidney / Q000473:pathology* / Q000601:surgery; D007670:Kidney Calices / Q000473:pathology*; D007834:Lasers; D008027:Light; D008297:Male; D009339:Needles; D009403:Nephrostomy, Percutaneous / Q000379:methods*; D019047:Phantoms, Imaging; D010820:Physicians; D011446:Prospective Studies; D011677:Punctures / Q000379:methods; D013337:Students, Medical; D052878:Urolithiasis / Q000628:therapy*
keywords: percutaneous nephrolithotomy; percutaneous renal surgery; renal stone; urolithiasis