Category: Basic Science: Stones
Introduction & Objective :
Pellethane is an aromatic polyether-based thermoplastic polyurethane noted for its strength, flexibility, and resistance to solvents. No studies have assessed the encrustation potential of either Pellethane or surface-treated Pellethane when exposed to urine. Herein we report the stability in artificial urine (AU) of uncoated Pellethane and surface-treated Pellethane with either 2-hydroxyethyl methacrylate (HEMA), a hydrogel, or tetraethylene glycol dimethyl ether (tetraglyme), both of which resist protein adsorption.
A batch-flow AU model with a static mixer was utilized (Figure 1), Pellethane, HEMA-grafted Pellethane, and tetraglyme-grafted Pellethane, were tested against a commercially available hydrogel-coated latex urinary catheter (Bard®) and a hydrophilic polymer-coated polyurethane ureteral stent (Cook Medical®). Four 30-day immersion trials were conducted (n=4). Encrustation was evaluated by the change in weight of each specimen and by electron microscopy.
All three Pellethane samples exhibited less mass gain than the stent (p<0.05). Tetraglyme exhibited less mass gain than the catheter (p<0.05). There was a trend for Pellethane (p=0.181) and HEMA-coated Pellethane (p=0.110) to have less mass gain than the catheter (Figure 2). The negative weight gain for the tetraglyme-coated Pellethane may have been due to extraction of components from the tetraglyme coating. Electron microscopy revealed far less encrustation for the pellethane samples, than for the catheter or stent; however, all pellethane samples had small amounts of encrustation present (Figure 3).
Compared to commercially available urinary catheters and ureteral stents, Pellethane with and without surface-treatment with HEMA or tetraglyme reduces encrustation in an artificial urine model.
Roshan Patel– Assistant Clinical Professor, University of California, Irvine, Department of Urology, Orange, California
Kevin Guan– Orange, California
Taylor Capretz– Orange, California
Krista Larson– Orange, California
Jaime Landman– Professor and Chair, Department of Urology, University of California, Irvine, Orange, CA, Orange, California
Buddy Ratner– Seattle, Washington
Ralph Clayman– Professor, University of California, Irvine, Department of Urology, Orange, California
Assistant Clinical Professor
University of California, Irvine, Department of Urology
Professor and Chair
Department of Urology, University of California, Irvine, Orange, CA
Professor Landman completed his medical training at Columbia University. He then completed his Urology residency at Mt. Sinai Hospital in New York before moving to St. Louis to complete his minimally invasive urology training at Washington University under the guidance of Dr. Ralph Clayman. Dr. Landman’s fellowship training focused on the minimally invasive treatment of renal diseases.
Prof. Landman focuses on developing new clinical approaches to minimally invasive and more effective treatments for surgical renal diseases such as renal cell carcinoma, urolithiasis and ureteropelvic junction obstruction. For the past decade, his clinical practice has been focused almost exclusively on the minimally invasive management of kidney disease with a focus on renal oncology and urolithiasis.
Since 2002 Dr. Landman has directed an active minimally invasive urology laboratory. His laboratory has focused largely on innovative minimally invasive solutions in the diagnosis and treatment of urologic malignancies, kidney stones and the development of minimally invasive surgical technologies.
A major focus of Dr. Landman’s efforts has been the didactic and technical training of students, residents and fellows. Dr. Landman has had an active role in medical student and resident education since 2001. Since 2002 Dr. Landman has been actively directing the Endourology sanctioned clinical and research fellowship, and he was until recently the program director for the UC Irvine Urology residency. Dr. Landman engendered and currently directs the LIFT (Leadership Innovation Fellowship Training) program at UC Irvine and has focused on helping medical students become academic leaders in Urology.
A current focus of Dr. Landman’s research remains didactic and technical training for students, residents and fellows. His research team continues to develop novel strategies for surgical education.