Antegrade ureteric stents are performed under fluoroscopic guidance, typically by an interventional radiologist or urologist. It is performed via percutaneous access from the kidney. It is usually performed using the access from a prior percutaneous nephrostomy, a so-called two-step procedure, although may be performed de novo.
The vast majority of ureteric stents placed are polyurethane in composition and require changing if left for longer than 3 months. Metallic stents, composed of coiled spirals, have been available in recent years for those with malignant ureteric obstruction. These may be left for 12 months or more since they are corrosion resistant. Metallic stents demonstrate a reduction in the rate of tumor regrowth compared with conventional stents.1
Most practitioners leave a 'covering nephrostomy' in place for 24-48 hours after stent insertion. This may be clamped to ensure good output from the stent (via the bladder), before the nephrostomy is removed and access is lost.
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 2.
- 1. Wah TM, Irving HC, Cartledge J. Initial experience with the resonance metallic stent for antegrade ureteric stenting. Cardiovasc Intervent Radiol. 2007;30 (4): 705-10. Cardiovasc Intervent Radiol (full text) - doi:10.1007/s00270-007-9043-4 - Pubmed citation
- 2. Stenting. (2001) Surgical Endoscopy. 15 (4): 423. doi:10.1007/s004640080116 - Pubmed