Metallic ureteric stents are a type of ureteric stent developed to offer improved symptomatic relief of obstruction when compared to polymeric (polyurethane) stents. They are often used in patients with chronic malignant ureteric obstructions who require placement of long-term ureteral stents to relieve the urinary obstruction and as a palliative measure to reduce pain and avoid major operation.
They aim to be better than polymeric (polyurethane) stents by:
- better maintaining ureteral patency in malignancy when conventional polyurethane stents are usually occluded
- having increased time intervals between stent changes
- being less prone to infection and bleeding
- causing less irritation of the lower urinary tract
An example of a metallic ureteric stent is the Memokath stent, which has an expanded top to anchor it within the ureter.
History and etymology
Somewhat surprisingly the word 'stent' is actually an eponym, originally named after Charles Stent (1807-1885), a largely-forgotten British dentist. He invented an improved material for forming dental impressions, and set up a company to manufacture it. During the Great War, J F Esser, a Dutch surgeon used a mold of Stent's Compound as a fixative for skin grafting in injured infantrymen. This innovative use, was rapidly adopted into practice, and stenting as a concept rapidly segued into multiple specialties 3.
- 1. Allen DJ, Longhorn SE, Philp T et-al. Percutaneous urinary drainage and ureteric stenting in malignant disease. Clin Oncol (R Coll Radiol). 2010;22 (9): 733-9. doi:10.1016/j.clon.2010.07.004 - Pubmed citation
- 2. Yachia D. Metal ureteral stents in chronic obstructions. Indian J Urol. 2011;27 (3): 307-9. Indian J Urol (full text) - doi:10.4103/0970-1591.85421 - Free text at pubmed - Pubmed citation
- 3. Stenting. (2001) Surgical Endoscopy. 15 (4): 423. doi:10.1007/s004640080116 - Pubmed