February 25, 2012
“I have been diagnosed with an 8mm stone in my left kidney and told I would be going for lithotripsy to have is broken up and will need a stent inserted for about a month or so. I have a huge concern with the stent portion of this. After much research on and off the web, it seems out of all patients that have had a stent inserted post lithotripsy, about 80% to 90% of the time it has resulted in extreme pain and discomfort. To me, it seems like this “technology” is not yet ready for prime time. I am now going to forgo the lithotripsy and deal with the stone just to avoid having the stent! So my question is, can you offer any comfort on this seeming archaic practice of stenting. Is it a requirement? What is the down side of not stenting after the lithotripsy?”
Stents have been used for decades and are not a new technology. Although much effort has been placed in trying to develop a pain-free stent, that goal has not yet been reached. As you point out, many patients do experience discomfort when stents are placed, although the percentage who experience “extreme” pain is likely lower than 80-90%.
Urologists will make a decision on whether to place a stent based on the type of surgery that is planned, the size of the stone being treated, whether a stone has been lodged for a period of time, the presence of other patient factors (renal impairment, solitary kidneys), and based on their own professional experience. Whether a stent is a “requirement” therefore can vary based on the patient, the stone, and the urologist.
The potential downside of not placing a stent is the risk of obstruction of the ureter due to either residual stone fragments or temporary swelling of the ureter after surgery. There may also be an increased risk of long term blockage (stricture) of the ureter if a stent is not placed in certain situations. However, a recent review article in the Journal of Urology found that among those undergoing uncomplicated ureteroscopy for stones in the ureter that were stented versus those that were not stented, there was no difference in the stone free rate, development of fever, unplanned medical visits, requirements for pain medication, or long term complications. Stented patients as expected had more stent related discomfort. Note though that these findings don’t necessarily apply to all stone patients as the study only included stones treated in the ureter with “uncomplicated” surgeries. (Pengfei and colleagues, “The results of ureteral stenting after ureteroscopic lithotripsy for ureteral calculi: A systematic review and meta-analysis”, Journal of Urology
Ultimately, discussing with your urologist whether you are a candidate for having a procedure without a stent may be your wisest choice. An 8mm stone is large enough that it is not likely to pass on its own and in some cases an untreated obstructing stone can lead to kidney damage or other problems if it is ignored.
In our “Ask KidneyStoners.org” section, we field questions from stone formers or their family members. See previous questions and answers here.