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Double-J stents: They're not trouble free


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Double-J stents: They're not trouble free

CE Credit is no longer available for this article (Expired: January 2004)



Originally posted January 2002

Double-J stents:
They're not trouble free

SHARON LEHMANN, RN, MS, CNS, and CHARLES A. DIETZ, JR., MD

SHARON LEHMANN is a clinical nurse specialist, and CHARLES DIETZ is an interventional radiologist in the department of radiology at the University of Minnesota in Minneapolis.

KEY WORDS: double-J stent, ureters, percutaneous nephrostomy tube (PNT), malignancy, contraindications, perioperative care, hematuria, urinary tract infection (UTI)

Double-J stents, the preferred treatment for relieving obstructed ureters, are increasingly being used in oncology patients. Though they're often so comfortable that patients may forget they have them, they're not without risks. Here's how you can help prevent, spot, and troubleshoot problems that can arise in this special patient population.

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Since its introduction in 1978, the double-J stent has become the gold standard for treating obstructed ureters.1 Not only was this stent the first and only model safe for long-term use, but the double-J design—a slender tube with opposite facing "J" hooks on the ends—significantly reduced the incidence of one of the most serious problems associated with earlier models: stent migration.

By anchoring the proximal J-hook within the renal pelvis and the distal J-hook within the bladder, the stent is kept from slipping up into the kidney or down into the bladder, where it could cause trauma, inflammation, and pain. (See the proper placement image.) Because the stent is entirely inside the body, infections were less common, too.

Over the years the demand for the double-J stent has increased dramatically, particularly among oncology patients.1 Advances in placement techniques and stent materials have further reduced complications such as stent breakage, encrustation, infection, and pain.1 Oncology patients find stents more comfortable than the traditional percutaneous nephrostomy tube (PNT). Since there's no need for an external drainage bag, patients may have a better self-image. Comfort, however, has a price.

Patients who have one or both ureters stented may not get proper follow-up care for many different reasons. Among them: transfer to another caregiver who is unaware of the stent's presence; a physician's forgetfulness; and a patient's failure to seek follow-up care. In one case, a patient's stent was "forgotten" for three years.2.

Despite the advances in technology, a double-J stent is never without potential complications. If you are caring for patients with these stents, you must understand the potential complications, be able to recognize signs and symptoms should they occur, and know how to properly intervene. Clearly, you must also know which patients are most likely to have an internal stent and how the stent is placed.

Who benefits from this stent, who doesn't

Double-J stents are often needed in oncology patients, for a variety of reasons. For one, the ureters of patients with gynecologic, urologic, or pelvic malignancies can become obstructed as a result of compression or invasion by a primary tumor or lymph node metastasis.3-5

In addition, radiation therapy can lead to ureteral stenosis or occlusion from the time treatment ends to as long as 10 years after therapy is completed.5 Also, patients who've undergone surgery for removal or debulking of a tumor may have iatrogenic trauma to the ureter that doesn't allow it to function properly.5

Placement of a stent is indicated in these patients not only for comfort and proper urinary function, but also because continuation of chemotherapy often depends on a patient having adequate kidney function.

Before placing a stent, though, the healthcare team is likely to consider how long the ureter has been obstructed (and thus how much damage the kidney may have) and the amount of cortex remaining in the kidney.

Indwelling ureteral stents are, however, contraindicated in certain situations. First and foremost, they are contraindicated when there are obstructions that have remained undetected for so long that a patient's kidney no longer functions.

Patients who have a fistula from the ureter or bladder to the bowel or vagina generally can't be treated with ureteral stents either because a fistula is a continuous source of infection. Similarly, patients with a partially obstructed ureter that results in a kidney infection should not be treated with ureteral stents. In this latter case, a nephrostomy tube should be placed to drain the urine until the infection clears. Then a double-J stent may be placed.3,5 Finally, a stent isn't indicated in patients whose kidneys are not producing at least 400 ­ 500 ml of urine a day because of the risk of encrustation, which will occlude the stent.

Perioperative care for double-J stent patients

Preparing a patient for double-J stent placement is similar to preparing patients for other surgical procedures: The patient's jewelry should be removed and the appropriate monitoring employed. Depending on the physician, patients usually receive antibiotics preoperatively and are given conscious sedation during the procedure. (The "Double-J stent placement " box reviews different approaches to the procedure.)

Before the procedure, you'll need to explain to your patients that they should expect some flank pain, blood-tinged urine, and painful or difficult urination for the first two to three days after the stent is placed.5 Also tell them that they'll need to drink eight or more eight-ounce glasses of water every day to encourage urination, help maintain the patency of the stent, and alleviate pain.

Stress, too, that they must void regularly throughout the day to prevent the bladder from becoming too full.5 An overly full bladder can result in the reflux of urine back through the stent and into the kidney. Urine reflux causes flank pain and an urgent need to void—both of which will subside when the patient urinates.

Once a stent is in place, patients will need to avoid certain activities, especially those that cause a lot of torso movement, such as aerobics. The restrictions on activity, of course, will vary by patient. The goal is to prevent overexertion that could lead to hematuria.

Postop prophylactic antibiotics are discouraged because they can cause a secondary fungal infection, which is difficult to treat. Instruct patients to seek treatment if any of the following symptoms lasts beyond the first three days: unexplained fever, flank pain, frequent urination, dysuria, or blood-tinged urine.5 These symptoms may be a sign of an infection or stent migration.

Double-J stents, however safe, could migrate at any time after placement, particularly smaller stents or those that are inadvertently malpositioned during insertion.3,5,6 (See the photo of a misplaced tip.)

If the stent is the type that allows extensive coiling, a knot can form during stent placement, particularly on the distal hook.7 (See the photo showing knot formation.) If it's not corrected, the knot can traumatize the ureteral wall, causing edema, possible stricture, or perforation.

Ensure that the stent is working properly

For double-J stent patients at our facility, we recommend a cystogram every three months to check for stent patency.8 This enables us to discover early on whether a patient has developed stones and/or encrustation of the stent(s). Either can occur when alkaline urine or frequent infections causes a calculus buildup.5,6

A stone can make stent removal impossible. (See the photo of stone formation.) Extracorporeal shock-wave lithotripsy (ESWL), a noninvasive method for disintegrating stones, may be needed to break it up. In the worst case, a patient will need the stone surgically removed.

If the stent becomes severely encrusted, it loses its flexibility and is prone to fracture. Percutaneous lithotripsy may be needed in this instance. To resolve precipitation before it becomes unmanageable, we recommend that patients take 1 ­ 2 gm a day of vitamin C.

As mentioned earlier, stent fracture and fragmentation may also become an issue. This complication tends to occur when a stent has been in place for an excessive period of time—say one or two years—and urine breaks down the stent. This complication underscores the importance of changing stents periodically.

Larger stents—10 ­ 14 Fr—need to be changed at least every nine months. Smaller stents—6 ­ 8 Fr—should be changed every three months.

At our facility, we replace internal stents under fluoroscopy as an outpatient procedure using conscious sedation; patients report little discomfort. Through the urethra, a snare is used to grab the old stent and pull it partially out of the patient. A guide wire is then passed up through the existing stent, which is then fully removed and a new stent passed over the guide wire. We take a urine culture, just in case a patient has an asymptomatic urinary tract infection (UTI), and the patient can then go home.

If a patient develops UTI, hematuria, or pain

Patients who are having recurrent UTIs should have their internal stents changed more frequently—for example, every three to six months for larger stents and every one to two months for smaller stents. Otherwise, the stent itself can serve as a source of infection.

If the infection is bacterial and the stent becomes occluded, it should be replaced with a retrograde catheter. In this case, the kidney will need to be irrigated with a triple antibiotic solution, and the patient started on oral or intravenous antibiotics. As soon as the UTI clears, the ureteral stent can be replaced. However, if the stent of a patient with a bacterial UTI remains patent, it can be left in place while systemic antibiotic therapy is started. The stent should then be changed approximately midway through the course of antibiotics.

In the case of a fungal infection, the stent is also replaced with a retrograde catheter and the kidney irrigated with an antifungal solution until the infection is cleared. (Clearing up the infection usually takes two to four days.) The patient should get additional intravenous or oral antifungal therapy as well.

Watch, too, for hematuria, which can occur with a UTI, or may be a sign of cystitis resulting from radiotherapy or anticoagulation therapy.5 If a patient is taking anticoagulants, even a little irritation or trauma from the stent can irritate the bladder and cause hematuria. If the bleeding can't be controlled or corrected, the patient may need to have the stent removed and be converted to a PNT to relieve ureter obstruction.

If a patient is experiencing bladder pain toward the end of voiding and no other etiology for the pain is found, he may only need phenazopyridine HCl (Pyridium), a urinary tract analgesic. However, in many such cases, fluoroscopic evaluation shows that the pain is caused by an excessively long stent resting against the bladder floor. Replacing the stent with a shorter one frequently eliminates the problem.5

Suspect renal abscesses in asymptomatic patients with occluded stents and in those who have delayed medical treatment of a symptomatic condition, such as a kidney infection.5 Infection from a renal abscess can spread retroperitoneally or infect the peritoneal cavity. (See the photo of an obstructed stent causing abscess formation.) These cases require extensive care, including external drainage of both the kidney and the abscess for a prolonged period of time and intravenous antibiotics. In the most serious cases, the patient may lose a kidney.

For all of these reasons, nurses caring for patients with a double-J stent should stress the importance of appropriate follow-up care. Even when the appropriate therapy appears to have resolved a problem, careful clinical and radiographic follow-up needs to continue.

Double-J stents can improve the self-image and quality of life for many individuals, particularly cancer patients. As with so many treatments, avoiding complications starts with clear communication among all the caregivers and regular follow-up. For double-J stent patients, strive to make that mandatory.

REFERENCES

1. Davis, J. W., & Fabrizio, M. D. (2000). What's new with stents and wires. Contemp Urol, 12(10), 29.

2. DeLucas, S., Milan, G. L., et al. (2000). Large calcifications on double-J ureteral endoprosthesis "forgotten" in situ. Report of a clinical case. Minerva Urol Nefrol, 52(4), 211.

3. Kellett, M. J. (2000). Interventional uroradiology: An update. BJU International, 86 (Suppl. 1), 164.

4. Feng, M. I., Bellman, G. C., & Shapiro, C. E. (1999). Management of ureteral obstruction secondary to pelvic malignancies. J Endourol, 13(7), 521.

5. Castaneda-Zuniga, W. R., Brady, T. M., et al. (1997). Interventional urolradiology: Part 1. Percutaneous uroradiologic techniques. In W. R. Castaneda-Zuniga, S. M. Tadavarthy, et al. (Eds.), Interventional radiology (pp. 1049 ­ 1269). Baltimore: Williams & Wilkins.

6. Monga, M., Klein, E., et al. (1995). The forgotten indwelling ureteral stent: A urologic dilemma. J Urol, 153(6), 1817.

7. Flam, T. A., Thounn, N., et al. (1995). Knotting of a double-J pigtail stent within the ureter: An initial report. J Urol, 154(5), 1858.

8. Mohan-Pillai, K., Keeley, F. X., et al. (1999). Endourological management of severely encrusted ureteral stents. J Endourol, 13(5), 377.



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Double-J stent placement

Double-J stents are made of polyurethane, polyethylene, or silicone. They range in size from 6 to 14 Fr and come in varying lengths. Each stent has end-holes and multiple side-holes that allow urine to drain freely from the kidney's upper collecting system, down through and around the stent, and into the bladder.1

Placement is made using either a cystoscope or percutaneous fluoroscopy. Small stents are usually placed by a urologist, while larger stents are generally inserted by an interventional radiologist. Placement is done in one of three ways: via an antegrade, retrograde, or lightning technique.

At our facility, a nephrostomy tube is usually placed first, percutaneously, through the flank and into the kidney prior to an antegrade or retrograde procedure. This way, kidney function can be assessed to ensure the kidney's ability to maintain an internal stent before insertion.1,2 Occasionally, a patient will receive a surgical treatment or chemotherapy through the nephrostomy tube that resolves the obstruction and eliminates the need for internal stents. However, when the obstruction persists, stent placement can be performed.

Traditionally, a double-J stent is placed in an antegrade direction through the nephrostomy tube's track down through the ureter into the bladder over a guide wire.1

A retrograde placement entails passing a guide wire from the nephrostomy site through the ureter to the bladder, where it is snared and pulled out through the urethra. The stent is passed over the wire in a retrograde direction until it reaches the correct position within the upper collecting system. Once the stent is in place, the guide wire is removed, allowing the ends of the stent to curl into the J shape and anchor the stent within the kidney and bladder. In a variation of this technique, the physician doesn't place the nephrostomy catheter. He does the retrograde placement cystoscopically, with a wire from below.

Retrograde placement can be difficult, especially if the patient has tortuous ureters or a tumor that impedes insertion. In such cases, a third technique, which we call the "lightning technique," can be employed.

For the lightning technique, the upper collecting system of the kidney is punctured with a thin needle, and a guide wire is passed through the needle and down the ureter through the obstruction and into the bladder. The wire is snared in the bladder and brought out the urethra. The stent is passed in a retrograde direction up the ureter and over the wire. Once the stent is in place, the wire and needle are removed.2

If there are concerns that the stent may not remain patent, the physician may place a small nephrostomy tube to drain urine from the kidney. The tube is left in place for 24 to 48 hours and is removed when the stent's patency is confirmed.

REFERENCES

1. Castaneda-Zuniga, W. R., Brady, T. M., et al. (1997). Interventional urolradiology: Part 1. Percutaneous uroradiologic techniques. In W. R. Castaneda-Zuniga, S. M. Tadavarthy, et al. (Eds.), Interventional radiology (pp. 1049 ­ 1269). Baltimore: Williams & Wilkins.

2. Kellett, M. J. (2000). Interventional uroradiology: An update. BJU International, 86 (Suppl. 1), 164.




Emil Vernarec, ed. Sharon Lehmann. Double-J stents: They're not trouble free. RN 2002;1:54.

Published in RN Magazine.

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