Double J Placement Methods Comparative Analysis

Indications

Double J stents have been used for more than 25 years and have become a staple of the urological endoscopic armamentarium. They are used mainly for stabilization of the ureter after surgery and to provide drainage through a ureter that may be obstructed, leaking, dysfunctional, or strictured. They are often used after extracorporeal shockwave stone surgery to minimize blockage from steinstrasse (multiple stone fragments that can clog and obstruct a ureter after lithotripsy), to bypass a larger immovable ureteral calculus, or to help identify the ureter radiologically or surgically.

Stents are also used as gentle ureteral dilators. If a tortuous, narrowed, or strictured ureter is encountered during ureteroscopy, placement of a double J stent will gradually dilate the lumen allowing for much easier ureteroscopy at a later date.

Or as one of the early pioneers in endourology, Dr. Arthur Smith, famously said, "When the going gets tough, the tough leave a stent and go home!"

The American Urological Association (AUA) guidelines suggest that a double J stent may be omitted after ureteroscopic lithotripsy when "there is no ureteral injury, no anatomical obstacle to fragment clearance and a normal contralateral kidney" but it fails to give any additional guidance on this subject.[2] There is also a wide gap in double J stent usage after ureteroscopy with 40.5% of cases in the Netherlands using stents after ureteroscopic procedures compared to about 93% in the US.[3] A preliminary study presented at the 2018 AUA meeting by Bower and Pareek attempted to create a practical algorithm to help identify situations where stents could reasonably be omitted.  They reported on 250 procedures in which 106 patients were eligible for stent omission based on their algorithm.  Of these 106, 60 went without double J stents, and none of these patients required readmission or additional surgery. Mainly, if a pre-procedural double J stent was in place or an access sheath was not used with a single, uncomplicated renal or distal ureteral stone, a post-procedure double J stent could probably be safely omitted.  Use of an access sheath without pre-procedure stenting would generally require a post-ureteroscopy double J stent. While further prospective studies are needed to confirm the validity of the algorithm, it serves as a useful and valuable starting point for consideration of stent omission after ureteroscopy.  

A summary of their algorithm for double J stent omission after ureteroscopic lithotripsy follows:

1. Abnormal contralateral kidney, renal failure (GFR<30), collecting system anatomical abnormality, or second stage procedure planned: Stent Suggested.
2. None of the above, a pre-procedure double J stent was NOT placed prior to ureteroscopy, but an access sheath was used: Stent Suggested.
3. Same as above but access sheath was NOT used: More than a single, uncomplicated distal ureteral or renal stone was treated: Stent Suggested.
4. All cases not covered above may consider the omission of the stent.  

Equipment

Having a wide variety of stent diameters and lengths is optimal. It is preferable to have both soft double J stents and rigid ones, but if you have to choose only one, pick the rigid type but insist on the largest possible selection of widths and lengths. The most commonly used size is a 6 French, 26 cm stent. Some very large patients will need longer stents, and some patients with a horseshoe or pelvic kidney will require very short ones.

Getting the guidewire or the open-ended catheter into the distal ureter can sometimes be challenging. Start by using the right size cystoscope sheath. Too small a sheath will not allow a 7 or 8 French stent, but if the cystoscope is too large, it will be challenging to secure and direct the open-ended ureteral catheter, stent, and guidewire. Consider using an Albarran deflecting bridge which allows for a little adjustable deflection at the tip of the cystoscope. This will permit approaching the ureteral orifice at a more acute angle, which will often work much better. The Albarran bridge will also provide additional intravesical stabilization of guide wires, ureteral catheters, and stents. Our personal preference is to use an Albarran bridge with a 70-degree lens and a 19 to 22 French cystoscope sheath for double J stent placement.

Be careful when advancing an open-ended catheter up the ureter without a guidewire. The edges of the catheter can be sharp enough to cause significant and unnecessary bleeding if pushed or forced up the ureter even with a guidewire. Some open-ended ureteral catheters have a slightly tapered tip, and these are preferable as they will tend to cause less ureteral trauma and reduce bleeding.

Ureteral balloon or solid dilators may occasionally be necessary and should be readily available. If a specific strictured area is identified on retrograde pyelography or fluoroscopy, it is helpful to place a marker (such as a sticky note or a signature request tab) directly on the fluoro screen to identify and mark its exact location. This is particularly helpful for balloon dilation. If such dilation is not successful for any reason, it may be preferable to leave a stent for passive dilation and return another day to complete the procedure.

Guidewires are a matter of personal taste. Hydrophilic wires are generally preferred but need to be kept moist for optimal performance. For this purpose, we always keep a wet sponge on the field to quickly moisten the wire and the stent. Always wipe from the outside (distal) end towards the urethral (proximal) end to avoid inadvertent dislodgement of the stent or guidewire.[4]

• Straight wires are generally preferred for routine use, but if the anatomy is abnormal, tortuous, or unusual, an angled tip wire will probably work better.
• Stiff shaft wires will help straighten a tortuous ureter more than standard wires.
• Use of a torque vise to secure a tight grip on the distal end of the guidewire can be very helpful in severe or challenging cases. This is especially useful with angled or curved tip guidewires.
• Use the open-ended catheter as a stabilizer for the guidewire and advance the wire from that point. Advance the open-ended catheter slowly over the guidewire as the wire advances.
• Place the open-ended catheter close to the ureteral stricture or obstruction. About 1 cm is optimal.
• Injection of contrast, lubricant, or lidocaine jelly through the open-ended catheter can often help facilitate passage of the guidewire. We like to use a combination of contrast and lidocaine gel. A smaller syringe (3 or 5 mL) is recommended for injection as the mixture may be quite viscous and very hard to inject with a larger needle.
• Advance the wire through the open-ended catheter while turning or twisting it with the torque vise. Monitor with fluoroscopy. Remember that the guidewire only has to pass through the obstructed area once. Confirm this passage fluoroscopically.  
• Once the guidewire has passed the obstruction, advance the open-ended catheter. Alternatively, ureteral dilation can be performed with a balloon or sequential solid ureteral dilators.  
• If the ureter remains tortuous, try placing a second, stiff guidewire. This can be introduced with a dual lumen catheter or directly through the cystoscope. An open-ended catheter can also be advanced over the guidewire for additional stiffness to help straighten a tortuous ureter. Be sure to re-measure the ureteral length after straightening as it is likely to become shorter.
• If it proves to be impossible to pass a guidewire, do not try to place the double J stent as this is likely to cause further ureteral damage and trauma. Consider a percutaneous nephrostomy and an antegrade approach instead.
• Metallic stents can be used when long-term drainage will be required, such as in obstructions caused by malignancy. They can typically remain in place without clogging for up to 1 year.

Personnel

Placing a double J stent is a two-person job, so make sure to have an assistant who is able and willing to help. It can be very frustrating as well as dangerous when the clinician is in the middle of a case, and the only available surgical technician or nurse cannot or will not assist.

Technique or Treatment

After trying innumerable variations, we have developed a technique that maximizes reliable double J stent placement while allowing for easy reversibility and guaranteed ureteral access. It also facilitates optimal stent positioning and renal pelvis stent coiling to minimize migration and patient discomfort.

Recommended Technique

Determine the Optimal Stent Length

Measure the ureteral length from the urinary meatus to the ureteropelvic junction (UPJ) either by a retrograde pyelogram (then subtract 10% due to radiologic magnification) or (preferred) determined directly with a marked ureteral catheter. This is done by placing the catheter tip at the UPJ and then cystoscopically checking the markings at the ureteral meatus.  A small amount of diluted contrast can be injected through the ureteral catheter to help identify the UPJ.  Double J stents only come in even lengths, so if the ureteral length measurement is an odd number of centimeters, choose the double J length that is 1 cm shorter. Note that the stent length does not include the curls at either end. As a general rule, the average ureter takes a 26 cm length stent.

Select the Optimal Stent Diameter and Stiffness

After establishing the ureteral length, the next issue is a decision on the width and rigidity (compressibility) of the stent. Softer stents may be more comfortable for the patient, but stiffer ones are likely to be more reliable and crush-resistant. With larger stones and tighter spaces, go with firmer material and a smaller diameter stent. Also, use a firmer catheter material when dealing with tortuous ureters and malignancies.  For ureteral strictures or severely infected kidneys, use larger diameter stents. Consider a metallic stent for malignancy or if the stent will be required permanently.

Guide Wire Placement (Routine)

With the double J stent selected, the next step is placing the guidewire. The guidewire can be inserted directly into the ureteral orifice, or it can be placed through a 5 or 6 French open-ended ureteral catheter. It should be advanced until the floppy tip coils in the renal pelvis as determined fluoroscopically.  

Guide Wire Placement (Difficult)

Guidewire placement is not usually a problem, but it can sometimes be challenging; especially when dealing with impacted stones, strictures, cancers, and tortuous ureters. First, try a different wire. We typically start with a hydrophilic stiff shaft straight tip but recommend an angled tip wire under challenging situations. The stiffer shaft wire helps straighten tortuous ureters, and it seems to be easier to advance with less bowing. In some cases, we may pass two wires to help straighten an unusually tortuous ureter. This can be quickly done with a dual lumen ureteral catheter.

When the guidewire does not advance easily, use a 5 French open-ended catheter to provide stability and prevent any bowing of the wire. Place the open-ended catheter within 1 cm of the obstruction and then gently try advancing the wire through the catheter while twisting the wire slightly right and left. Use fluoroscopy for guidance and a torque vise or similar device to better handle, twist, and advance the guidewire.

The obstruction only has to be successfully traversed once to provide proximal access. If the only partial passage is achieved, advance the open-ended catheter gently and carefully over the guidewire as much as possible, and then repeat the guide wire advancement technique described above. For even more excellent stability and support, a dual lumen catheter can be substituted for the standard open-ended catheter.

A combination of lidocaine jelly and contrast can be advantageous in these situations. Inject a small amount through the open-ended catheter to help with visualization and reduce ureteral spasm. Use of a smaller syringe (3 or 5 mL) is recommended for this retrograde injection due to the high viscosity of the mixture.

Use Retrograde Pyelography

With the guidewire in place, advance the open-ended catheter to the UPJ and measure the ureteral length. The guidewire can be safely removed to do a retrograde as long as the tip of the open-ended catheter is beyond any stricture or blockage. A few milliliters of diluted contrast can be injected to help identify the UPJ. After measuring the ureteral length, replace the guidewire, and remove the ureteral catheter. If the ureter is particularly tortuous, consider using a second guidewire to help straighten it. If the ureter is significantly narrowed or tight, ureteral dilation with either a Nottingham dilator, tapered ureteral catheter, or balloon dilator may be needed. In these situations, consider using a smaller diameter double J stent immediately, then replacing it with a wider one later after a reasonable period of passive dilation from the original stent.

We like to position the fluoroscope so that the center of the renal pelvis is in the exact middle of the radiologic viewing field so that even if the injected contrast has dissipated or drained away, there is still an indicator for the precise location of the center of the renal pelvis. 

Keep the Guide Wire Moist

Start at the most distal end of the guidewire and wipe just the tip with a wet sponge from proximal to distal. This avoids having the guidewire accidentally perforate the sponge and getting caught. Then wipe the rest of the guidewire from distal to proximal to prevent accidental extraction or movement of the guidewire. We keep a wet sponge handy on the patient’s knee and another on the side of the water basin to help keep these hydrophilic supplies moist and wet whenever they are used or manipulated.

Load the Stent

Loading the proximal end of the double J stent, the end without the safety thread, over the distal tip of the guidewire can sometimes be tricky. Use the supplied plastic outer sheath, if available, as an aid to straighten out the curve of the stent. Adjust the plastic sheath so that the proximal tip of the stent is just inside the sheath, about 1 cm from the tip.

Make sure the double J and guidewire are both very moist if using hydrophilic materials; otherwise, it can be challenging to advance the stent over the guidewire. Most hydrophilic guidewires and stents dry out very quickly and then become sticky.

Advance the guidewire into the stent. Place one hand on the distal end of the plastic outer sheath and pinch the stent and plastic sheath together. This extra stability facilitates the passage of the guidewire through the stent as otherwise, the guidewire may push the stent out the back of the plastic sheath. Once the guidewire is through the proximal coiled end of the stent, slide the sheath outwards to straighten out the distal coil and push the guide wire all the way through. Remove the plastic outer sheath once the guidewire has passed through the entire stent and is visible at the distal end.  Do not remove the thread yet.

Place the Double J Stent

Push the stent into the cystoscope until you can see the proximal end of the stent enter the distal ureter. Then have the pusher placed over the guidewire and use it to slide the stent over the guidewire into the ureter and up into the renal pelvis. Now pull the guidewire back slightly so that the tip of the wire is just below the curl of the proximal end of the stent. Hold the pusher, guidewire, and the safety thread from the stent together as a single unit and gently move it a few centimeters in and out of the ureter as previously described. This will allow the soft, proximal end of the stent to curl up in the renal pelvis naturally.  By holding the stent, pusher, and thread together, the entire process can be easily reversed just by pushing the guidewire back into the renal pelvis allowing for stent repositioning or even complete removal while leaving the guidewire in place for ureteral access.

Remove the Dangler/Safety Thread

When completely satisfied with the proximal renal curl of the stent and its distal (bladder) placement, with the black mark from the stent visible at the ureteral orifice, cut one end of the dangler/safety thread close to the cystoscope nipple and altogether remove the thread. Make sure the knot is distal to the point where the thread is cut. Removal of the thread with the guidewire and pusher still in place stabilizes the double J and minimizes the chances of inadvertently moving or extracting the stent. The thread can optionally be left in place and secured at the end of the case to the inner thigh or dorsum of the penis. This is recommended only when the expected need for the stent is one week or less as it is prone to accidental early dislodgement or removal by the patient.  Do Not Remove the Dangler/Safety Thread Until Completely Satisfied With the Proximal Stent Tip Coiling in the Renal Pelvis as Well as the Distal Stent Position!

Guide Wire Removal

Immediately after the thread is removed, pull the guidewire entirely out. (Up to this point, the guidewire has been in place just below the proximal coiled stent tip, stabilizing the position of the stent, so it does not move or get pulled out accidentally.) To safely remove the pusher, first advance the pusher in a few centimeters until the distal stent tip has been pushed out of the cystoscope sheath and the end of the stent is visible completely inside the bladder. Now it is safe to remove the pusher.  If the coiling is not optimal in the bladder, a biopsy forceps or grasper can be used to adjust it through the cystoscope.

Review the final position of the double J stent fluoroscopically and cystoscopically to ensure optimal placement and positioning. Finally, empty the bladder and remove the cystoscope.

Change or Remove the Stent Appropriately

Double J stents will tend to develop stone material on their surfaces, particularly in the renal pelvis and the bladder, which can make standard cystoscopic stent removal extremely difficult or even impossible. For this reason, stents typically need to be changed regularly or removed. It is the surgeon's responsibility to keep track of the stents and make sure his patients do not fail to have them changed or withdrawn at the appropriate time. In pregnancy, changing stents every 4 to 6 weeks is recommended due to rapid encrustation. Most standard stents can remain for 3 to 6 months, but this time will vary according to the patient's urinary chemistry and stone-producing propensity. Every commercially available stent will have a maximum recommended indwelling time, which should be followed.

Side Effects from Double J Stents

Stent discomfort can be minimized with alpha-blockers like tamsulosin and alfuzosin. Additionally, the use of such agents pre-operatively has been shown to be helpful in reducing post-operative stent-related irritative bladder symptoms.[5] Bladder irritability (frequency and urgency) can be treated with anticholinergic medications as needed. While oxybutynin has been used most often, mirabegron has been shown to be equivalent and offers fewer side effects.[6][7]  PDE5 inhibitor medications have shown a benefit in reducing stent-related discomfort but combination therapy with alpha-blockers and antimuscarinics appears to be the most effective overall therapy, such as the use of tamsulosin with solifenacin.[8][9][10]

Stents will need to be changed more often in pregnant ladies than in other patients, even those with previous nephrolithiasis. Consider a percutaneous nephrostomy as an alternative.

Some degree of hematuria is not uncommon with stents; especially in patients on anticoagulants. This is typically only an issue if the hematuria is excessive. It is essential to inform patients that they may have hematuria with stents to avoid undue anxiety.

Remember that once a double J stent has been placed, it is the responsibility of the surgeon to make sure that it is removed appropriately and at the right time. When stents are inadvertently left in place for months, or even years longer than intended, they inevitably become calcified and may also move or migrate out of position. It is the surgeon's responsibility to make sure the stent is removed in a timely fashion and not forgotten.

Complications

The significant primary complications of double J stents are almost always associated with leaving the stent indwelling too long, which causes stent migration, encrustation, stone formation, and fragmentation of the stent. Urinary tract infections, renal failure, and sporadic fistula formation to the iliac vessels have also been reported.

Stent migration is most likely to occur in a patient who is long overdue for stent removal or replacement. The stent can end up entirely within the renal pelvis or the bladder. A lesser degree of migration can be due to selecting a stent that is much too short. In this case, the distal end of the stent, the portion that is usually in the bladder, will migrate up the ureter and not be visible on cystoscopy. These will need to be removed with ureteroscopy.

Stents that make full coiled circles at either end when placed are less likely to migrate than those with only partial coiling.

Stones and stent encrustation will occur in any stent left in the urinary system long enough. Risk factors include lengthy indwelling stent time (3 months or more), chronic renal failure, pregnancy, history of previous nephrolithiasis, chemotherapy, and preexisting metabolic or anatomical abnormalities. Standard extracorporeal shockwave lithotripsy (ESWL) is frequently used for this problem; it works best on lower volume stent encrustation and stone disease.

Stents are manufactured with strong materials. However, they can sometimes fracture and fragment into pieces. While this is usually associated with prolonged indwelling time, it can happen much quicker. The fracture points are almost always at the sites of the stent drainage holes. Fortunately, this complication is quite rare.[11]

The best treatment for these complications is prevention, which is why it is so important to avoid prolonged stent indwelling time. As stated earlier, most stents should be changed optimally at three-month intervals and certainly by six months. In pregnancy, we recommend stent changes even more frequently: every 4 to 6 weeks due to the accelerated encrustation that occurs.[12]

Treatment of existing complications usually involves ureteroscopy and percutaneous endourological procedures and is almost always successful.

Three months is the usual recommended maximal indwelling stent time, but six months should be the absolute maximum limit. Patients with stents that are lost to follow-up or "forgotten" are much more likely to encounter these complications.

Rarely, complications from "forgotten" double J stents can be serious, and several deaths have been reported.[13]

Clinical Significance

The use of double J stents in urology is now standard practice, yet the optimal technique for their placement has not been described previously. After a careful analysis, the technique mentioned earlier, that includes exact ureteral length measurements for ideal stent length selection, use of the dangler/safety thread to help manipulate the stent into optimal position, and partial extraction of the guidewire to promote proximal stent tip coiling while maintaining total control of the stent, guidewire, and pusher, is recommended. This technique optimizes patient safety and comfort and facilitates easy stent replacement, if needed, without losing ureteral access.

Enhancing Healthcare Team Outcomes

The use of double J stents has revolutionized endoscopic urological practice and is now an integral part of urology. an interprofessional team consisting of nurses and physicians use the optimized placement technique described, and improved stent selection will minimize patient discomfort, side effects, and complications while retaining access for maximal patient safety and comfort.

Nurses looking after patients with double J stents should be fully aware of the potential adverse effects and call the urologist if there are any untoward events. Care coordination with an interprofessional team will result in the best outcomes. [Level 5]