Spontaneous Ureteral Stent Fragmentation

Abstract

A series of spontaneous multiple fragmentations of 3 ureteral stents presenting with a variety of clinical features is reported. Physical analysis measuring the tensile mechanical properties was done of the retrieved fragments together with 2 new stents, as well as electron microscopy scanning of the retrieved fragments. This methodology in evaluating fractured stents is unique in its capability to determine the accelerated aging process of stent material and to our knowledge has not been reported previously in this context. The retrieved catheters were moderately incrusted. The tensile elongation (maximal elongation at break point), known to be a sensitive indicator of the aging process of plastic materials, was dramatically decreased in the retrieved stents. The fractures in all catheters retrieved as well as in the new stents were found to pass exclusively through the side holes. Fragmented catheters had a distinctive electron microscopic appearance and physical properties, which may be defined in a systematic manner and may contribute to further refinement of stent quality.

Can the Complicated Forgotten Indwelling Ureteric Stents be Lethal?

“…The ureteric stents insertion is very common in modern day urologic practice but the forgotten stents remain a major concern [1,5,6,8,11]. Many a times, the stents are not removed because either the patients are not aware of the stent or just because of their non-compliance.…”

“…The stent fragmentation can occur if stent is left for more than one year in the urinary system [1][2][3][4][5][6]8]. The hostility of the urinary solution is responsible for the fragmentation of the stents [2,4,6].…”

“…The severe encrustation and stone formations may cause obstructions and this may threaten the renal unit [2]. The forgotten steats itself may get complicated such as calcification, upward migration and fragmentation [1,2,[5][6][7][8][9]. The complicated stents need management by endourological and some auxiliary techniques such as extracorporeal or intracorporeal, lithotripsy to make the patients stent free [1,2,8,10,11].…”

Neue Materialien zur Harnleiterschienung — Mythen und Fakten

“…Wenn auch in der vorliegenden Literatur die Berichte über Materialversagen mit signifikanter Häufigkeit eher Silikonelastomere betreffen, wird von Zisman auch über drei Fälle berichtet, in welchen Polyurethan betroffen war [31].…”

Late Complications of Ureteral Stents

“…The major late complications in patients with indwelling ureteral stents include stent migration [7], stent fragmentation [8, 9], or worsened hydronephrosis with flank pain and infections [6]. We report the late complications in a series of 110 stented kidneys.…”