Ureteral Stents: Necessarily a Pain?

A variety of ureteral stents.

Ureteral stents have been used in urology for over 50 years. Ureteral stents are soft, pliable, and, most often made of plastic, tubes designed to allow urine to flow through or around them to bypass an obstruction in the urinary system. Ureteral stents are commonly called "double-J" or "pig-tailed" catheters, referring to the soft coils at either end of the tube that prevent the stent from migrating in the urinary system. Common indications, or reasons for placing a ureteral stent include:

• Intrinsic (or internal) ureteral obstruction – as from kidney stone
• Extrinsic (or external) ureteral obstruction – as from a compressing malignancy
• Post-operatively following ureteroscopic surgery
  • Manipulation of a kidney stone
  • Biopsy of renal pelvis or ureteral malignancy
  • Dilation of a ureteral stricture

While the risk of complications while placing a stent or following are low, many patients can experience stent pain which can vary from a nuisance to excruciating, intolerable pain. This blog will focus on the mechanisms and treatment of ureteral stent pain.

 

EPIDEMIOLOGY OF STENT PAIN & SYMPTOMS

Stent pain of varying degrees is estimated to affect upwards of 80% of patients having one placed.[1,2] Specific symptoms and estimated incidences include:

• Irritative Voiding Symptoms (most common)
  • Frequency (50-60%)
  • Urgency (57-60%)
  • Dysuria (40%) – discomfort when voiding
  • Incomplete Emptying (76%)
• Pain or Discomfort
  • Flank (19-32%) – especially at the end of voiding
  • Suprapubic (30%)
• Incontinence
• Hematuria (25%) – visible blood in the urine

[1,3-9]

 

MECHANISMS OF STENT PAIN & SYMPTOMS

Ureteral stents can allow "reflux" of urine
from the bladder to the kidney.

Most symptoms associated stents are attributed to mechanical stimuli and irritation from the coil that rests in the bladder. The ureteral orifices (where the ureter enters the bladder) defines the lateral edge of the trigone (or central portion of bladder defined by the ureteral orifices and the urethra) so that the stent rests on this, very sensitive, area of the bladder. Most irritative symptoms are worse during the day, indicating that awareness plays a role in stent symptoms.[1] Alternatively, studies also demonstrate that stents can move as much as 2.5cm in movement of the stent based solely on patient position – indicating that daytime activity also likely plays a role in symptoms.[10] Interestingly, a randomized clinical trial demonstrated that longer stents were associated with more symptoms and worse quality-of-life.[11]

Flank pain is believed to be due to reflux of urine from the bladder to the kidney during voiding. While stents are designed to allow urine to flow from the kidney to the bladder, there is no mechanism to prevent urine flowing up from the bladder to the kidney – especially during voiding when bladder pressures can be quite high. Flank pain at the end of voiding is often mild to moderate and not related to stent length or positioning.[11-13] Expectation of flank pain can often alleviate many patient concerns with this phenomenon. Suprapubic pain is most often related to stent position and mechanical irritation of the trigone.

Incontinence is either due to severe mechanisms (as described above), or if the stent migrates distally and bypasses the urethral sphincter, allowing urine to pass unabated out of the bladder.

Hematuria can be related to the underlying process being treated (for example, obstructing kidney stone), result from the surgery (use of a laser or biopsy instruments) or the stent rubbing along the urothelium (lining of the urinary system).[14]


 

PREVENTING STENT PAIN & SYMPTOMS

The best way to prevent stent pain is to avoid placing a stent. However, it is important to note that most ureteroscopic procedures require a stent to be placed to prevent infection or injury; and failing to place a stent in a patient in whom it is necessary can lead to worse symptoms, hospital readmission, a possible second procedure or permanent injury. The American Urological Association (AUA) Guidelines on the Management of Ureteral Calculi state that "Stenting following uncomplicated ureteroscopy is optional."[15]

Stents come in a variety of lengths and calibers. Choosing an appropriate stent size and positioning appropriately can prevent most significant symptoms. While a number of systems have been developed for adult [5,14,16] and pediatric [17] patients to predict the "best" stent length for a patient, in general a stent should rest proximally in the renal pelvis and distally curl just into the bladder. While the proximal curl (in the kidney) has no correlation to stent symptoms, a distal curl that crosses the midline in the bladder is associated with more irritative voiding symptoms.[14]

A variety of medications and stent-coating materials have been tried to improve stent symptoms. Local anesthetics have demonstrated no benefit [7] while some stents coated with antibiotics, made of less irritative materials or of tapered design have demonstrated less discomfort in early studies.[18]

 

TREATING STENT PAIN & SYMPTOMS

A number of medications and routes of administration have been used to treat stent symptoms. A number of intravesical medications (given in the bladder) have demonstrated mixed results with no clear benefit. The best studied medications for stent discomfort include the alpha-blockers afluzosin,, tolterodine and tamsulosin. A number of studies have demonstrated improved symptoms, decreased use of pain medications, better sleep and quality-of-life with alpha blockers were compared to placebo.[19-22] Another study failed to demonstrate a benefit to the anticholinergic, oxybutynin, but a small benefit to phenazopyridine (pyridium).[23]

 

SUMMARY

• Many urologic conditions and procedures necessitate the use of ureteral stents.
• Symptoms related to stent placement can affect upwards of 80% of patients with the most common symptoms being irritative voiding symptoms and pain.
• Most symptoms related to an indwelling stent are related to mechanical irritation.
• Therefore, stent symptoms are best managed by:
  • Placing a stent only when needed
  • Placing a stent that is properly sized and positioned for the patient
  • Using medications that mitigate the reaction of the urinary system to the stent

 

 
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[2] Byrne RR, Auge BK, Kourambas J, et al. Routine ureteral stenting is not necessary after ureteroscopy and ureteropyeloscopy: a randomized trial. J Endourol. 2002;16:9–13.
[3] Chew BH, Knudsen BH, Denstedt D. The use of stents in contemporary urology. Curr Opin Urol.2004;14:111–5
[4] Haleblian G, Kijvikain K, de la Rosette J, Preminger G. Ureteral stenting and urinary stone management: a systematic review. J Urol. 2008;179:424–30.
[5] Hao P, Li W, Song C, Yan J, Song B, Li L. Clinical Evaluation Of Double-Pigtail in Patients with Upper Urinary Tract Diseases: Report of 2685 cases. J Endourol. 2008;22:65–70.
[6] Thomas R. Indwelling ureteral stents: Impact of material and shape on patient comfort. J Endourol. 1993;7:137–40. [PubMed]
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[8] Rane A, Saleemi A, Cahill D, Sriprasad S, Shrotri N, Tiptaft R. Have stent-related symptoms anything to do with placement technique? J Endourol. 2001;15:741–4.
[9] Smedley FH, Rimmer J, Taube M, et al. 168 Double J (pigtail) ureteric catheter insertions: A retrospective review. Ann R Coll Surg Engl. 1988;70:377–9.
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[11] Al-Kandari AM, Al-Shaiji TF, Shaaban H, Ibrahim HM, Elshebiny YH, Shokeir AA. Effects of Proximal and Distal Ends of Double-J Ureteral Stent Position on Postprocedural Symptoms and Quality of Life: a Randomized Clinical Trial. J Endourol. 2007;21:698–702.
[12] Ramsay JW, Payne SR, Gosling PT, Whitfield HN, Wickham JE, Levison DA. Effects of double-J stenting on unobstructed ureter: an experimental and clinical study. Br J Urol. 1985;57:630–4.
[13] Mosli H, Farsi H, al-Zemaity MF, Saleh TR, al-Zamzami MM. Vesico-ureteral reflux in patients with double pigtail stents. J Urol. 1991;146:966–9.
[14] Ho CH, Chen SC, Chung SD, Lee YJ, Chen J, Yu HJ, et al. Determining the Apropriate Length of a Double-Pigtail Ureteral Stent by Both Stent Configurations and Related Symptoms. J Endourol.2008;22:1427–31.
[15] Preminger, et al. Management of Ureteral Calculi: European Association of Urology (EAU) and American Urological Association (AUA) Nephrolithiasis Panel (2007). http://www.auanet.org/education/guidelines/ureteral-calculi.cfm

[16] Hruby GW, Ames CD, Yan Y, Monga M, Landman J. Correlation of ureteric length with anthropometric variance of surface body habitus. BJU Int. 2007;99:1119–22. 
[17] Palmer JS, Palmer LS. A simple and reliable formula for determining the proper JJ stent length in the pediatric patient: Age + 10. Urol. 2007;70:264.
[18] Ricardo Miyaoka and Manoj Monga. Ureteral stent discomfort: Etiology and management. Indian J Urol. 2009 Oct-Dec; 25(4): 455–460.
[19] Deliveliotis C, Chrisofos M, Gougousis E, Papatsoris A, Dellis A, Varkarakis IM. Is there a role for alpha1-blockers in treating double-J stent-related symptoms? Urology. 2006;67:35–9. [PubMed]
[20] Beddingfield R, Pedro RN, Hinck B, Kreidberg C, Feia K, Monga M. Alfuzosin to Relieve Ureteral Stent Discomfort: A Prospective, Randomized, Placebo Controlled Study. J Urol. 2009;181:170–6. [PubMed]
[21] Park SC, Seo IY, Jeong HJ, Oh SJ, Rim JS, Jeong YB. The effect of alfuzosin and tolterodine in treating double-J stent-related symptoms. J Urol. 2008;179:289.
[22] Damiano R, Autorino R, De Sio M, Giacobbe A, Palumbo IM, D'Armiento M. Effect of Tamsulosin in Preventing Ureteral Stent- Related Morbidity: A Prospective Study. J Endourol. 2008;22:651–5.
[23] Norris RD, Sur RL, Springhart WP, Marguet CG, Mathias BJ, Pietrow PK, et al. A Prospective, Randomized, Double-blinded, placebo-controlled comparison of extended release oxybutynin versus phenazopyridine for the management of postoperative ureteral stent discomfort. Urology. 2008;71:792.