EM@3AM: Ureteral Stent Complications
- Aug 10th, 2024
- Jacob Tauferner
- categories:
Authors: Jacob Tauferner, MD (EM Resident Physician, UTSW/ Dallas, TX); Mihir Patel, MD (EM Attending Physician, Dallas, TX) // Reviewed by: Sophia Görgens, MD (EM Physician, Northwell, NY); Cassandra Mackey, MD (Assistant Professor of Emergency Medicine, UMass Chan Medical School); Alex Koyfman, MD (@EMHighAK); Brit Long, MD (@long_brit)
Welcome to EM@3AM, an emDOCs series designed to foster your working knowledge by providing an expedited review of clinical basics. We’ll keep it short, while you keep that EM brain sharp.
A 55-year-old male with history of colon cancer, hydronephrosis, and right ureteral stent placed 10 weeks ago presents to ED with intermittent hematuria that has become more frequent over the last 3 days. He denies dysuria, fever, abdominal pain, or flank pain. His vital signs include BP 98/64, HR 98, T 97.5, RR 22, SpO2 99% on room air. On exam he has conjunctival pallor and tachypnea. His capillary refill is 3 seconds.
Question: What is the potential life-threatening diagnosis?
Answer: Ureteroarterial fistula
Background:
- The main objective of a ureteric stent is to allow passage of urine and reduce complications related to obstruction in the urinary tract. [1]
- Stents are an important part of many urological procedures, such as endoscopic or open surgery for retroperitoneal tumors of fibrosis, ureteral strictures, or treatment for reno-ureteral stones. [2]
- Ureteral stents are characterized by a multitude of designs, material composition, elutable substances and surface coatings.
- The vast majority of these devices are placed for a relatively short amount of time (1–2 weeks), a portion of patients will require more chronic (weeks to years) of ureteral stenting. [3]
- They may cause patient discomfort, bacterial colonization, hematuria, irritative voiding symptoms, and deposition of urine constituents. [2]
Complications: [2,4-6]
- Urinary tract infection
- Pyelonephritis
- Microscopic or gross hematuria
- Stent-related pain
- Stent malpositioning
- Stent migration
- Irritative bladder
- Stent obstruction
- Stent encrustation
- Fragmentation of stent
- Erosion of urinary tract
- Vascular-ureter fistula
- Retroperitoneal hematoma
Urinary Tract Infections:
- Can range from simple cystitis to sepsis of urinary source.
- Patients with ureteral stents are more prone to a urinary tract infection (UTI). [6]
- As a foreign body, ureteral stents are often colonized by bacteria. 60–80% indwelling ureteral stents form a biofilm at approximately 2 weeks, yet only 5% will result in a UTI. [5,6]
- Longer indwelling times are associated with an increasing risk for urinary tract infections and sepsis. [7,8]
- Patients with diabetes mellitus and chronic renal failure are at a higher risk for urinary tract infections. [6]
- There is no consensus on management of ureteral stents in infectious situations, however patients are often given a short antimicrobial course in order to decrease stent colonization. [5, 6]
- For pyelonephritis, antibiotics and renal US to evaluate for obstruction and/or plain films to evaluate the tract and stent positioning, as well as a consult for potential urgent stent exchange are recommended [4,5,6]
Hematuria:
- Microscopic and mild gross hematuria are usually related to urothelial irritation and self-limited. Hematuria is a common postoperative complication and can be secondary to the stent placement itself or ureteroscopy. [2,6,9]
- However, gross hematuria may occur from erosion through a segment of the urinary tract.
- Persistent and significant bleeding after prolonged placement of stent may be due to ureteric arterial fistula, a rare and devastating complication of stenting.[9]
- Persistent gross hematuria requires a urology consult. The hematuria typically resolves following stent removal. [4,6]
Stent-related pain:
- Lumbar pain is a frequent complication experienced by approximately 19-32% individuals with ureteral stents. [2]
- Appears to be a result of urine reflux towards the kidney with an excessive rise in intrapelvic pressure that ultimately translates into pain.[2,10,11]
- Recommend ruling out other serious complications and treat with anticholinergics like oxybutynin or tolterodine and alpha-1 blockers. [4,6]
Irritative bladder:
- Several studies in literature describe the symptoms related to ureteral stents and their respective estimated incidence: irritative voiding symptoms including frequency (50-60%), urgency (57-60%), dysuria (40%), incomplete emptying (76%), and suprapubic pain (30%) [11,12]
- Urgency and incontinence are thought to be due to the presence of a stent itself [11]
- All of these symptoms can be secondary to stent morbidities such as urinary tract infection and encrustation and should be excluded by urinalysis and KUB as indicated. [11,13]
- Anticholinergics (tolterodine, oxybutynin), as well as alpha-1 blockers (Tamsulosin, alfuzosin) have shown efficacy in symptomatic treatment of bladder irritation. [6,17]
Stent Malpositioning:
- Defined as an incorrect position relative to initial placement.
- Intraoperative complication characterized by misplacement of proximal end of the stent into the ureter, placement into the retroperitoneums, or potentially renal parenchymal perforation. [2]
- A malpositioning complication like intravascular migration of double J stent, ureteroarterial fistula, hemoperitoneum, or knotted stent are reported as very rare. [14]
- Management with plain film of abdomen and potential urology/IR consult. [6]
Stent Migration:
- Can occur proximally into the pyelocaliceal system or ureter and distally towards the bladder. It can potentially cause urine outflow obstruction. [2]
- Incidence of stent migration is 5.8%. [2,15]
- Occurs when a stent is too short for the ureter or with prolonged indwelling time
- Plain films and urology/interventional radiology consultation is recommended. [4]
Stent Obstruction:
- Flank pain may suggest stent obstruction but can also be associated with a functioning stent. [10]
- Renal function on blood chemistry studies may not reflect acute obstruction, especially if the obstruction is unilateral. [10]
- Hydronephrosis on imaging can be misleading. Patients with long-standing upper tract obstruction, placement of a stent may not return the renal collecting system to a normal appearance. [10]
- Voiding cystography and color doppler ultrasonography are useful diagnostic modalities in order to assess obstruction. These should be used in conjunction with consult to urology/IR. [10]
Stent Encrustation:
- Presence of the stent provides a framework for deposition of urine constituents to the stent. [10]
- Long-term stenting, urinary tract infection, a history of stone disease, oncologic treatment, chronic kidney failure, and metabolic or congenital defects all favor stent encrustation. [2]
- The most important risk factor is prolonged indwelling stent time. Found to occur in 9.2% of stents retrieved before 6 weeks, 47.5% stents in place for 6 to 12 weeks, and in 76% in stents in place >12 weeks. [6,10]
- Prevention includes dilution of the urine with high fluid intake and an aggressive treatment of UTI. [10]
- Management includes supine KUB and urology/IR consultation for potential removal of the stent. [6]
Stent Fragmentation:
- Occurs when the stent loses tensile strength when the polymers degrade, and the stent hardens [16]
- Encrustation in forgotten stents is occasionally linked to stent breakage. [2]
- Evaluate with plain films of abdomen and urology/IR consult. [6]
Urinary Tract Erosion or Fistulization:
- Characterized by erosion of the stent into adjacent structures, especially the arterial system
- Usual presentation is intermittent hematuria in a patient with a stent, but massive hematuria to the point of circulatory collapse may occur and may be provoked by ureteral stent manipulation. [10]
- Resuscitation as needed and emergent urology and interventional radiology consult is recommended. [4]
Pearls:
- Ureteric stents allow passage of urine and reduce complications related to obstruction in the urinary tract.
- An abdominal x-ray can be used to evaluate complications including stent fragmentation, encrustation, migration, and malpositioning.
- Chronic indwelling stents are exchanged every 3 months on average. A prolonged time of stent placement is associated with an increase in complications.
- When a patient presents with gross hematuria, consider urinary tract erosion and ureteroarterial fistula.
A 54-year-old man with a history of renal cell carcinoma status post right nephrectomy presents with acute left flank pain radiating to the groin. A CT scan of the abdomen and pelvis without contrast demonstrates a 5 mm stone in the proximal left ureter with moderate to severe hydronephrosis. His pain is well controlled and his urinalysis does not show evidence of infection. Which of the following is the appropriate plan?
A) Administer ceftriaxone
B) Administer tamsulosin
C) Admission with urology consultation
D) Discharge if creatinine is normal
Answer: C
Renal calculi are quite common, occurring most commonly in young adults and middle-aged men. Four types of renal calculi exist and they include calcium, uric acid, struvite, and cysteine calculi. The majority of stones are calcium caused by either overproduction of calcium, excess ingestion of calcium, or excess oxalate that binds with calcium to form stones. As stones move along the genitourinary tract, impaction often occurs. When this happens, it begins to affect the renal blood flow and glomerular filtration rate on the affected side. Renal excretion shifts to the unobstructed side. In most situations, the unaffected collecting system is able to compensate for the partial functional impairment on the affected side. Patients who have only one kidney and an obstructing stone need admission with urology consultation for possible ureteral stenting or stone removal through percutaneous nephrolithotomy. Surgical intervention helps to decompress the obstruction and preserve the renal function of the solitary kidney.
Most patients (with two kidneys) may be discharged with a stone if the creatinine is normal (D) and there is no evidence of obstruction with infection, intractable pain, intractable vomiting, or evidence of kidney dysfunction. Empiric antibiotics (A) with agents such as ceftriaxone are not indicated routinely in the treatment of a ureteral stone. If the urinalysis shows evidence of infection, antibiotics are often prescribed. If there is evidence of infection with obstruction, patients require urology consultation for possible stent placement and stone removal. Tamsulosin (B) is an alpha antagonist used for smooth muscle dilation of the ureter. This has been advocated as a medical expulsion therapy in the treatment of distal ureteral stones, although is not always effective, especially in larger stones. There is limited evidence to support this intervention.
Further Reading:
- Comprehensive overview of ureteral stents based on clinical aspects, material and design.Central European Journal of Urology. Published online 2023. doi:https://doi.org/10.5173/ceju.2023.218
- Geavlete P, Georgescu D, Mulțescu R, Stanescu F, Cozma C, Geavlete B. Ureteral stent complications – experience on 50,000 procedures.Journal of Medicine and Life. 2021;14(6):769-775. doi:https://doi.org/10.25122/jml-2021-0352
- Yang L, Whiteside S, Cadieux PA, Denstedt JD. Ureteral stent technology: Drug-eluting stents and stent coatings.Asian Journal of Urology. 2015;2(4):194-201. doi:https://doi.org/10.1016/j.ajur.2015.08.006
- Ureteral stent complications – WikEM. wikem.org. Accessed August 29, 2023. https://wikem.org/wiki/Ureteral_stent_complications#Background
- Fugaru I, Bhojani N, Andonian S, Sameh W, Fahmy N. Management of infected indwelling ureteral stents: An international survey of urologists.Canadian Urological Association Journal. 2022;17(3). doi:https://doi.org/10.5489/cuaj.7994
- www.uptodate.com. Accessed August 29, 2023. https://www.uptodate.com/contents/placement-and-management-of-indwelling-ureteral-stents#H1673162276
- Paick SH, Park HK, Oh SJ, Kim HH. Characteristics of bacterial colonization and urinary tract infection after indwelling of double-J ureteral stent.Urology. 2003;62(2):214-217. doi:https://doi.org/10.1016/s0090-4295(03)00325-x
- Nevo A, Mano R, Baniel J, Lifshitz DA. Ureteric stent dwelling time: a risk factor for post-ureteroscopy sepsis.BJU International. 2017;120(1):117-122. doi:https://doi.org/10.1111/bju.13796
- Ilie VG, Ilie VI. Ureteric Stent Use – Part of the Solution and Part of the Problem.Current Urology. 2017;11(3):126-130. doi:https://doi.org/10.1159/000447206
- Dyer R, Chen M, Zagoria R, Regan J, Hood C, Kavanagh P. Complications of Ureteral Stent Placement. Accessed August 29, 2023. https://www.uroschool.gr/sites/default/files/session/attachments/anastasiadis_15-11.00_1.pdf
- Monga M, Miyaoka R. Ureteral stent discomfort: Etiology and management.Indian Journal of Urology. 2009;25(4):455. doi:https://doi.org/10.4103/0970-1591.57910
- Hao P, Li W, Song C, Yan J, Song B, Li L. Clinical evaluation of double-pigtail stent in patients with upper urinary tract diseases: report of 2685 cases.Journal of Endourology. 2008;22(1):65-70. doi:https://doi.org/10.1089/end.2007.0114
- Ho CH, Chen SC, Chung SD, et al. Determining the appropriate length of a double-pigtail ureteral stent by both stent configurations and related symptoms.Journal of Endourology. 2008;22(7):1427-1431. doi:https://doi.org/10.1089/end.2008.0037
- Altay B, Erkurt B, Kiremit MC, Güzelburç V. A rare complication of ureteral double-J stenting after flexible ureteroscopy: renal parenchymal perforation.Turkish Journal of Urology. 2015;41(2):96-98. doi:https://doi.org/10.5152/tud.2015.53367
- Mallikarjuna, G., Ravichander, G., Ravi, J., & Praveen, C. (2018). Ureteric double-J stent related complications: a single tertiary care center experience from South India.Int J Res Med Sci,6(12), 3846-3851.
- Memon, N. A., Talpur, A. A., & Memon, J. M. (2007). Indications and complications of indwelling ureteral stenting at NMCH, Nawabshah.Pak J of Surg,23(3), 187-91.
- Park SC, Jung SW, Lee JW, Rim JS. The effects of tolterodine extended release and alfuzosin for the treatment of double-j stent-related symptoms.Journal of Endourology. 2009;23(11):1913-1917. doi:https://doi.org/10.1089/end.2009.0173
