title: Comparison of Flow Characteristics of Novel Three-Dimensional Printed Ureteral Stents Versus Standard Ureteral Stents in a Porcine Model.
abstract: OBJECTIVE
  We compared the flow characteristics of novel three-dimensional (3D) printed ureteral stents with four conventional double-pigtail stents in an ex vivo porcine model.
  
  
  METHODS
  In six ex vivo porcine urinary systems with kidneys and ureters intact, we deployed a 5F occlusion catheter in an interpolar calix. We tested each system with antegrade irrigation with a 0.9% saline bag placed 35 cm above the renal pelvis. We evaluated four standard stents (6F Universa® Soft, 7F Percuflex,™ 7/10F Applied Endopyelotomy, 8.5F Filiform Double Pigtail) and compared them with a 9F 3D printed prototype stent. For each stent, we measured the total, extraluminal, and intraluminal flow rates.
  
  
  RESULTS
  The mean total flow rates for 3D printed stents were significantly higher than the 6F, 7F, and 7/10F stents (P<0.05). No significant difference was seen in the total flow rate for the 3D printed stent and the 8.5F stent. The mean extraluminal flow rates for the 3D stents were similar to those of 7F stents, but significantly lower than 6F stents (P<0.001) and 8.5F stents (P<0.05) and higher than 7/10F stents (P<0.001). The mean intraluminal flow rates for the 3D printed stents were significantly higher than the 6F, 7F, 7/10F, and 8.5F stents (P<0.05).
  
  
  CONCLUSIONS
  In this pilot study, 3D printed stents manifested a mean total flow rate comparable to the flow rates of contemporary stents. Continued advances in technology and material may permit functionally feasible 3D printed ureteral stents.
authors.affiliation: 1 Department of Urology, University of California , Irvine, Orange, California.
authors.forename: Michael
authors.initials: M
authors.lastname: Del Junco
authors.affiliation: 1 Department of Urology, University of California , Irvine, Orange, California.
authors.forename: Renai
authors.initials: R
authors.lastname: Yoon
authors.affiliation: 1 Department of Urology, University of California , Irvine, Orange, California.
authors.forename: Zhamshid
authors.initials: Z
authors.lastname: Okhunov
authors.affiliation: 1 Department of Urology, University of California , Irvine, Orange, California.
authors.forename: Garen
authors.initials: G
authors.lastname: Abedi
authors.affiliation: 1 Department of Urology, University of California , Irvine, Orange, California.
authors.forename: Christina
authors.initials: C
authors.lastname: Hwang
authors.affiliation: 2 Department of Engineering, University of California , Irvine, Orange, California.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Dolan
authors.affiliation: 1 Department of Urology, University of California , Irvine, Orange, California.
authors.forename: Jaime
authors.initials: J
authors.lastname: Landman
mesh_terms: D000818:Animals; D002404:Catheterization; D057785:Catheters; D007668:Kidney / Q000601:surgery*; D007682:Kidney Pelvis; D010865:Pilot Projects; D066330:Printing, Three-Dimensional; D011474:Prosthesis Design; D012212:Rheology; D015607:Stents; D013552:Swine; D014513:Ureter