Comparative Evaluation of Materials Used for Internal Ureteral Stents

Abstract

The materials used in the fabrication of self-retained internal ureteral stents should provide strength, flexibility, low surface friction, radiopacity, biodurability, biocompatibility, and reasonable unit cost. Polymeric biomaterials currently used for stent construction include polyurethane, silicone, Silitek, C-Flex, and Percuflex. Comparative evaluation of these materials in the context of the requirements for stent structure and function suggests advantages and disadvantages for all of them. We believe that the most important attributes for an internal ureteral stent are ease of insertion, effective restoration and maintenance of flow, resistance to migration, significant biodurability, and biocompatibility. Based on our physical testing of stents fabricated from these materials, as well as clinical and laboratory experience, we believe that C-Flex and Percuflex are the most suitable materials for stent construction.

Stent-Change Therapy in Advanced Malignancies with Ureteral Obstruction

“…Newer stents provide a combination of inside/outside diameter, tensile strength, perdurability, and biocompatibility superior to those of prior models. 17 Many authors have recommended percutaneous nephrostomy with or without antegrade stenting in this population first, rather than an attempt at retrograde ureteral stenting. For example, Feng et al recommended antegrade drainage initially in patients likely to fail internal drainage (i.e., those with cervical cancer).…”

Double-J Ureteric Stent Encrustations: Clinical Study on Crystal Formation on Polyurethane Stents

“…For long-term usage, selection of suitable polymers along with monitoring of stent function and position at least 3 monthly still remain mandatory [ 1,2,4,15], Encrustations on long-term indwelling urethral cathe ters (all-silicone, latex and silicone-coated latex) have pre viously been examined using various methods mainly including chemical analysis, X-ray diffraction, atomic ab sorption spectroscopy, infrared spectroscopy, extended X-ray absorption Fine structure spectroscopy and scannning electron microscopy.…”

Use of Ureteral Stents after Endopyelotomy

“…Polyurethane and Percuflex have a high tensile strength, C-Flex is of intermediate strength, and silicone is the most susceptible to breakage.40 To compensate for poor tensile strength, the wall of the stent may be increased in size; however, a thicker wall reduces the internal diameter of the stent and compromises urine flow. 40 Additionally, materials of high tensile strength can accommodate large drainage holes, whereas materials of low tensile strength are further weakened by sideholes. Endopyelotomy stents composed of polyurethane or Percuflex with a high tensile strength maintain a high ratio of internal to external diameter and contain large sideholes.…”