Ureteral catheterization: when it is needed, how it is performed, the difference between a stent and a nephrostomy, and possible complications

In modern urology, ureteral catheterization typically refers to the endoscopic insertion of a catheter or internal stent into the ureter through the urethra, bladder, and ureteral orifice. In practice, this most often involves retrograde placement of a double-J ureteral stent, rather than a "regular catheter" in the common sense. Ureteral catheterization is necessary to restore urine flow, bypass an obstructed area, temporarily protect the ureter after surgery, and for certain diagnostic purposes, such as retrograde contrast injection. [1] [2]

It's crucial to immediately distinguish between three closely related, but distinct, devices: a temporary open ureteral catheter, a double-J internal stent, and a nephrostomy. An open catheter is typically used briefly, for example during or immediately after an endoscopic procedure. A double-J stent remains in place longer and is held in place by coils in the kidney and bladder. A nephrostomy, on the other hand, passes through the skin directly into the kidney rather than through the bladder and is a different drainage method. [3] [4]

From a clinical perspective, the goal of all these solutions is the same: to quickly and safely restore urine flow from the kidney. This is especially important in cases of obstruction, as urinary stasis increases the risk of pain, hydronephrosis, infection, sepsis, and decreased kidney function. The Cleveland Clinic clearly states that, without treatment, ureteral obstruction can damage the kidney, and in severe cases, lead to renal failure and sepsis. [5]

Ureteral catheterization is not the same as treating the underlying cause of the obstruction. It often serves as an intermediate, yet critical, step: drainage must first be established, and only then can stone removal, tumor treatment, stricture correction, or postoperative edema be addressed. This is why the European Association of Urology guidelines and radiological standards consider stent placement a decompression method rather than a definitive solution in all cases. [6] [7] [8]

Another important modern shift is that stenting is no longer considered absolutely mandatory after any ureteroscopy or before any lithotripsy. The UK's National Institute for Health and Care Excellence and the European Association of Urology emphasize that routine stenting after uncomplicated ureteroscopy is unnecessary, and pre-treatment stenting before shock wave lithotripsy in adults is generally not recommended. This means that by 2026, ureteral catheterization will be less of a "routine procedure" and more of a targeted solution for a specific problem. [9] [10]

Table 1. What is most often meant by ureteral catheterization

Option	What is this?	Typical goal
Open ureteral catheter	Thin catheter without long-term internal retention	Contrast, temporary drainage, assistance during the procedure
Double J stent	Internal stent with coils in the kidney and bladder	Long-term internal drainage
Nephrostomy	Drainage through the skin directly into the kidney	External or combined drainage when a stent is not possible

Source. [11] [12]

Table 2. What ureteral catheterization is not

Misconception	What is it really?
It's the same as a catheter in the bladder.	No, the ureteral catheter is inserted higher, into the ureter itself.
It's the same as a nephrostomy.	No, the nephrostomy tube passes through the skin into the kidney.
This is always the final treatment	No, it's often a temporary decompression.
It's always the same technique	No, there is a retrograde and antegrade pathway.

Source. [13] [14]

Table 3. Main modern tasks of the ureteral catheter or stent

Task	Clinical meaning
Restore urine flow	Protect the kidney from pressure and infection
Bypass the obstruction	Maintain drainage until definitive treatment
Support the ureter after intervention	Let the swelling go down and the wall heal.
Facilitate repeat endoscopy	Prepare the ureter for the next step
Perform retrograde contrast enhancement	Clarify the anatomy and level of the obstacle

Source. [15] [16]

Table 4. Where the role of stents is especially important today

Scenario	Why is a stent useful?
Stone with obstruction	Quickly restores outflow
Infected obstruction	Helps to decompress the system immediately
After endoscopy of the stone	Reduces the risk of blockage due to swelling or fragments
Benign or malignant compression	Preserves kidney function
Urine leakage or healing after surgery	Supports internal drainage

Source. [17] [18]

Table 5. What has changed in modern practice

Earlier	Now
The stent was often placed almost automatically	A stent is placed for more specific indications.
After uncomplicated ureteroscopy, a stent was considered almost mandatory	Routine stenting after uncomplicated ureteroscopy is not recommended.
Pre-stenting before shock wave lithotripsy has been widely used	It is not routinely offered to adults.
The stent was considered only as an "outflow tube"	Now they take into account the quality of life, symptoms and duration of standing

Source. [19] [20]

When ureteral catheterization is urgently needed

The most dangerous situation is infected obstruction of the upper urinary tract. The European Association of Urology explicitly defines renal obstruction due to urinary tract infection or anuria as a urological emergency. In such a situation, not only antibiotics are needed, but also urgent decompression, because without drainage of infected urine, the risk of sepsis and progressive deterioration of the condition increases dramatically. [21] [22]

The European Association of Urology guidelines identify two main options for this type of decompression: placement of an internal ureteral stent and percutaneous nephrostomy. Based on available data, both techniques are considered comparable in terms of success and complication rates, with differences primarily related to organizational details, length of hospital stay, quality of life, and technical feasibility in a specific clinical situation. [23]

In acute infections, it is especially important to understand that a stent is only the first step. Final stone removal or other active treatment of the underlying cause of obstruction is postponed until the infection is controlled and the patient has completed an appropriate course of antibiotic therapy. The European Association of Urology specifically recommends delaying definitive stone treatment until sepsis resolves. [24]

If retrograde stent placement fails, this does not mean the end of options. The 2026 radiology standards indicate that when attempting antegrade placement from the kidney, if a stent cannot be passed immediately, it is advisable to maintain a nephrostomy drain for 48-72 hours to allow swelling and ureteral tortuosity to subside, and then attempt stenting again. This is an important practical principle: in difficult anatomy, it is sometimes necessary not to "push harder," but rather to first safely decompress the system. [25]

Stones aren't the only causes that may require urgent stent placement. Ureteral obstruction can also be caused by tumor compression, stricture, blood clot, postoperative edema, pregnancy, endometriosis, and other causes. The Cleveland Clinic lists stones, scar tissue, tumors, cysts, vascular causes, gastrointestinal inflammatory processes, and a number of congenital anomalies as causes of blockage. Therefore, ureteral catheterization is not just a procedure "for stones," but for any clinically significant obstruction that requires rapid preservation of drainage and renal function. [26]

Table 6. Signs that drainage should not be delayed

Sign	Why is it dangerous?
Fever due to obstruction	Infected hydronephrosis is possible.
Anuria or a sharp decrease in urine	Risk of kidney failure
Severe pain and increasing dilation	Risk of kidney damage and deterioration of the condition
Systemic signs of sepsis	Urgent decompression is needed
Impaired renal function	The urine flow must be restored quickly.

Source. [27] [28]

Table 7. Stent and nephrostomy for emergency decompression

Parameter	Ureteral stent	Nephrostomy
Path	Through the urethra and bladder	Through the skin into the kidney
Efficiency in emergency decompression	Comparable	Comparable
Hospitalization	On average it may be shorter	On average it may be longer
Quality of life	Often limited to stent symptoms	External drainage is also inconvenient
The choice depends on	Anatomy, experience, causes of obstruction	Anatomy, experience, causes of obstruction

Source. [29]

Table 8. When a nephrostomy is especially likely

Situation	Why a stent may be more difficult
It is impossible to pass the obstruction from below	There is no safe retrograde access
Severe swelling and tortuosity of the ureter	The conductor does not pass reliably
Complex tumor compression	The lumen is sharply deformed
The need for rapid external control of outflow	Nephrostomy is easier for monitoring
Failed attempt at retrograde stenting	Alternative decompression is needed

Source. [30] [31]

Table 9. What to do with decompression in case of infection

Action	Why is this necessary?
Start antibiotic therapy immediately	Control of bacterial infection
Take urine and blood for culture	Determine the sensitivity of the pathogen
Assess the degree of obstruction and renal function	Understand the gravity of the situation
Delay final stone removal	Do not increase the risk in the presence of an active infection
If the condition worsens, consider intensive care.	Sepsis may require extended support

Source. [32] [33]

Table 10. What causes of obstruction most often lead to ureteral catheterization?

Cause	An example of a clinical situation
Stone	Acute ureteral block with pain and hydronephrosis
Stricture	Cicatricial narrowing after inflammation or surgery
Tumor compression	Compression of the ureter from outside
Postoperative edema	Temporary obstruction of outflow after endoscopy
Clot or inflammatory detritus	Temporary mechanical blockade of the lumen

Source. [34] [35]

How does the procedure work and how does a temporary catheter differ from a stent?

In the most typical scenario, a ureteral stent is placed by a urologist in an operating room or surgical center under anesthesia. The Cleveland Clinic describes the standard procedure as follows: a cystoscope is inserted through the urethra, a flexible guidewire is then passed through it into the blocked ureter, and a stent is then placed over the guidewire. This approach is referred to as retrograde catheterization, as the catheterization proceeds from the bottom up—from the bladder to the kidney. [36]

During placement, the physician uses fluoroscopy, sometimes ultrasound, or a combination of imaging techniques to guide the stent. Finally, one coil of the stent remains in the kidney and the other in the bladder, holding the system in place. This distinguishes the double-J stent from an open ureteral catheter, which can be used as a temporary contrast agent, for measuring the length of the ureter, or for very short postoperative drainage. [37] [38]

An open ureteral catheter is important in modern practice as a technical tool. The StatPearls section on stent placement methods describes how a 5- or 6-French diameter catheter can be inserted into the renal pelvis over a guidewire, minimally filling the system with dilute contrast, and thus visualizing the renal pelvis and measuring the length of the ureter. This helps to correctly select the length of the future stent and reduce positioning errors. [39]

Retrograde stent placement sometimes proves difficult due to a stone, stricture, severe ureteral tortuosity, or tumor compression. In such cases, stiffer or hydrophilic guidewires, support catheters, balloon dilation, and other techniques are used. However, the most important modern rule is: if a guidewire cannot be safely passed through the obstruction, the stent should not be forcibly pushed through, as this increases the risk of ureteral injury. In such cases, a nephrostomy and antegrade approach should be considered. [40]

From the patient's perspective, the procedure is typically minimally invasive and is often performed on an outpatient basis. The Cleveland Clinic reports that stenting typically takes less than 30 minutes, and in most cases, patients can go home the same day after observation. The American College of Radiology and the Radiological Society of North America's Radiology resource describes a similar logic for antegrade procedures: the patient undergoes blood tests beforehand, discusses medications, is sometimes asked to temporarily fast from food and drink, and is then observed until their condition stabilizes. [41] [42]

Table 11. Standard steps for retrograde ureteral catheterization

Step	What's happening
Insertion of a cystoscope	The doctor enters the bladder
Search for the ureteral orifice	The required side is determined
Conducting the conductor	The path is laid through the block area
Installation of a catheter or stent over a guidewire	Form internal drainage
Position control	Check that the renal and vesical ends are in the correct position

Source. [43]

Table 12. Temporary open catheter and double-J stent

Parameter	Open catheter	Double J stent
Standing period	Very short	From days to months
The main role	Technical and diagnostic	Long-term internal drainage
Fixation with curls	No	Yes
Frequency of symptoms	Usually lower in very short term	Higher due to longer standing
Typical application	Contrast, measurement, short outflow	Obstruction, postoperative drainage, long-term ureteral protection

Source. [44] [45]

Table 13. What to prepare before the procedure

What is being assessed?	Why is this important?
Blood tests and kidney function	You need to understand the initial state
Taking anticoagulants and other medications	This affects safety.
Allergy to contrast and anesthesia	To prevent complications
Type of obstruction according to visualization	To choose the right path and tools
Presence of infection	To add antibiotics and drainage in time

Source. [46] [47]

Table 14. What can complicate stent placement

Factor	Why is he in the way?
The driven stone	The lumen is sharply narrowed or blocked
Stricture	The conductor passes with difficulty
Tortuous ureter	The risk of misdirection increases
Tumor compression	The lumen is deformed from the outside
Severe swelling of the mucous membrane	Temporary anatomical narrowing

Source. [48] [49]

Table 15. When to switch to the antegrade route

Situation	What does this mean?
Retrograde obstacle failed to pass	Nephrostomy is being considered
First, you need to relieve the pressure and inflammation.	A nephrostomy drainage is placed
After decompression, the anatomy became better	Repeated attempt at stenting from above or below
There is chronic tortuosity and dilation.	The antegrade approach may be technically more convenient
There is a combined task of drainage and subsequent stenting	A step-by-step scheme is possible

Source. [50] [51]

When is a stent really needed after ureteroscopy and when is it not?

One of the most significant changes in modern urology relates precisely to this topic. The UK's National Institute for Health and Care Excellence recommends against routine stenting in adults following ureteroscopy for ureteral stones smaller than 20 millimeters. The European Association of Urology formulates the same idea even more categorically: in uncomplicated ureteroscopy, stent placement is not necessary after the procedure. [52] [53]

Why is this important? Because a stent is beneficial not only for its ability to support outflow, but also for the significant cost to the patient. The European Association of Urology emphasizes that routine stenting after uncomplicated stone removal is associated with increased postoperative morbidity and costs, while Cleveland Clinic and quality-of-life studies show that in many patients, stenting causes significant urinary symptoms, pain, hematuria, and impairment of normal daily activities. [54] [55] [56]

However, completely eliminating stents is not suitable for everyone. The European Association of Urology recommends stent placement in patients with an increased risk of complications, such as ureteral trauma, residual fragments, bleeding, perforation, urinary tract infection, pregnancy, and in questionable cases where it is better to prevent an emergency than to return to drainage later. So, the question is not "stent for all or none," but "who really benefits from a stent?" [57]

Another important modern point concerns pre-treatment stenting for stone treatment. The National Institute for Health and Care Excellence does not recommend pre-treatment stenting before shock wave lithotripsy in adults. The European Association of Urology also writes that routine stenting before ureteroscopy is not required, although it acknowledges that pre-treatment stenting for kidney stones may, in some cases, improve conditions for subsequent endoscopic treatment. [58] [59]

Finally, if a stent is needed, modern practice attempts to reduce the symptom burden. The European Association of Urology notes that alpha-blockers reduce stent-associated morbidity and improve tolerability. The Cleveland Clinic also notes that tamsulosin can help with stent-related pain. This doesn't make the stent "comfortable," but it allows for better symptom control if its placement is truly necessary. [60] [61]

Table 16. When stent placement is not necessary after ureteroscopy

Condition	Why a stent may not be placed
The stone removal was without complications.	There is no apparent need for additional drainage.
No ureteral injury	The risk of blockade is lower
No significant bleeding	Less risk of tamponade by fragments and clots
No infection	No additional protective outflow is required
There is no doubt about the patency of the ureter	Stent symptoms can be avoided

Source. [62] [63]

Table 17. When a stent is most often justified after ureteroscopy

Situation	Why is a stent needed?
Trauma or perforation of the ureter	Support healing and drainage
Fragments remain	Reduce the risk of blockade
Severe swelling after manipulation	Preserve the lumen of the ureter
Urinary tract infection	Improve drainage
Pregnancy or questionable clinical situation	Reduce the risk of emergency complications

Source. [64]

Table 18. What current guidelines say about routine stenting

Scenario	Modern conclusion
After uncomplicated ureteroscopy in adults with a ureteral stone less than 20 millimeters	Do not offer routinely
Before shock wave lithotripsy in adults	Do not offer routinely
Before ureteroscopy in a normal situation	Not routinely required
In complicated and questionable cases	The solution is individualized

Source. [65] [66]

Table 19. How to reduce symptoms when a stent is already in place

Approach	What does it affect?
Alpha-blocker	May reduce urinary symptoms and colic
Selecting a shorter standing period	Reduces overall symptom burden
Smaller stent diameter in appropriate cases	May reduce pain and irritation
Stent on a thread in suitable cases	Allows you to remove it earlier and easier
Explaining to the patient the expected symptoms	Reduces anxiety and late visits for predictable reasons

Source. [67] [68]

Table 20. Short-term temporary catheter as an alternative

Scenario	What does modern literature show?
Uncomplicated ureteroscopy	Very short drainage is possible
One day of catheter placement	May give similar results in individual cases
A long-term internal stent is not needed.	It is possible to reduce the symptom burden
The choice depends on the surgeon and the context.	There is no universal solution

Source. [69]

What are the symptoms and complications and how to live with a stent?

The most common problem with internal ureteral stents is not a catastrophic complication, but rather unpleasant symptoms that significantly impair quality of life. The Cleveland Clinic reports that up to 80% of people with stents experience at least one complication or significant symptom, and a study of quality of life after ureteroscopy and stenting describes pain, frequent urination, hematuria, and incontinence as typical and sometimes quite distressing. [70] [71]

These complaints are not accidental. The distal stent irritates the bladder, and urination can cause pressure surges and discomfort in the side or kidney. The Cleveland Clinic directly explains that when the bladder contracts, its wall can rub against the lower end of the stent, causing some patients to experience a pulling sensation, increased urination frequency, burning, and increased pain during urination. [72]

In a 2025 prospective study from BMC Urology, symptoms were also very common: 86% of patients reported urinary symptoms, over 70% reported dysuria, over half reported hematuria, and nearly half reported lumbar or abdominal pain. The study does not replace guidelines, but it clearly reflects real-world clinical experience: stent placement is far from neutral and requires not only placement but also active discussion of symptoms with the patient. [73]

In addition to symptoms, there are also mechanical complications: displacement, blockage, fracture, encrustation, and infection. The Cleveland Clinic notes the risk of stent blockage, breakage, or displacement, and a 2024 review of stent technologies specifically lists bacterial adhesion, encrustation, pain, and hematuria as key problems with existing models. This is why stent indwelling periods are kept as short as possible, and if long-term stent replacement is necessary, scheduled replacement is recommended. [74] [75]

It is especially important for the patient to be aware of warning signs: high fever, increasing pain, severe inability to urinate, severe hematuria with clots, a sharp decrease in outflow from a solitary kidney, suspected stent displacement, or deterioration in health due to the stent. Moderate blood in the urine or increased urination frequency are usually expected, but the combination of pain, fever, and deterioration in general condition requires prompt contact with a urologist, as this may indicate infection, stent blockage, or ongoing obstruction. [76] [77]

Table 21. The most common symptoms with a ureteral stent in place

Symptom	Why does it occur?
Frequent urination	Bladder irritation from the lower end of the stent
Urgency and urgency	Trigonometric irritation of the bladder
Burning sensation when urinating	Local irritation and sensitivity
Pain in the side when urinating	Transfer of pressure up the stent
Blood in urine	Mechanical irritation of the mucous membrane

Source. [78] [79]

Table 22. Which complications are considered more serious?

Complication	Why is it dangerous?
Urinary tract infection	It may develop into pyelonephritis or sepsis.
Inlay	Complicates removal and may block the stent
Migration	Disrupts drainage
Blockage	Returns obstruction
Breakage or fragmentation	May require additional endoscopic intervention

Source. [80] [81]

Table 23. Which symptoms most often have the greatest impact on quality of life?

Complaint	How does it manifest itself in everyday life?
Pain	It interferes with sleeping, walking, and working.
Frequent urge to urinate	Travel and normal activities are restricted.
Dysuria	Makes urination unpleasant
Hematuria	Increases anxiety and requires observation
Sexual dysfunction or pain during intercourse	Worsens the intimate and emotional sphere

Source. [82] [83]

Table 24. When to contact a doctor urgently

Sign	Why is this a reason not to wait?
Fever and chills	Possible infection due to obstruction or stent
A sharp increase in pain	Possible block, migration or complication
Heavy blood in urine with clots	Significant trauma or block may occur.
Almost no urine with a single kidney or bilateral problem	Threat to renal function
Suspected stent displacement	Drainage may become ineffective

Source. [84] [85]

Table 25. Stent maintenance and replacement periods

Situation	What do they usually do?
Short-term stent after intervention	More often they are left for days or weeks
Long-term need for tumor compression or narrow ureter	Replacement possible every 3-6 months
Standing for a long time without control	Not recommended due to increased complications
Before deletion	They evaluate whether the cause of the obstruction has gone away

Source. [86] [87]

FAQ

Are ureteral catheterization and double-J stent placement the same thing?
Not quite. Broadly speaking, stent placement is a variant of ureteral catheterization. But the term "catheterization" is broader and can include short-term placement of an open catheter for contrast, measurement, or very short-term drainage without a long-term internal stent.[88][89]

Is a stent always needed for a ureteral block, rather than a nephrostomy?
No. For urgent decompression of an obstruction, a stent and a nephrostomy are considered comparable in effectiveness. The choice depends on the level of the obstruction, infection, anatomy, accessibility, and the experience of the team. If an inferior stent cannot be passed, a nephrostomy is a logical and often safer next step. [90] [91]

Why is a stent sometimes not placed after stone removal?
Because after an uncomplicated ureteroscopy, routine stenting is no longer considered mandatory. Current guidelines assume that a stent doesn't always improve outflow, but almost always adds symptoms and worsens quality of life. Therefore, it is placed only where the actual benefit outweighs the expected discomfort. [92] [93]

Is it normal to urinate more often and have blood in the urine while in a stent?
Yes, moderate hematuria, increased urinary frequency, urgency, and discomfort when urinating are common stent symptoms. However, if these are accompanied by a high fever, severe pain, worsening general condition, or heavy bleeding with clots, a follow-up examination is necessary. [94] [95]

How long can a stent be in place?
Most stents are temporary and last from a few days to a few weeks. If a stent is needed longer, for example due to tumor compression or persistent narrowing, a urologist will typically schedule regular replacements, often every 3-6 months, to reduce the risk of infection and other complications. [96] [97]

Can stent discomfort be reduced with medication?
In many cases, yes. The European Association of Urology notes that alpha-blockers reduce stent-associated morbidity and colic, and the Cleveland Clinic notes that tamsulosin can help with stent-related pain. However, medication is not a substitute for controlling the underlying obstruction and promptly removing the unnecessary stent. [98] [99]

Key points from experts

Margaret Pearl, MD, PhD, is a professor of urology and internal medicine at the University of Texas Southwestern Medical Center and holds the Pearl Endowed Professorship in Urology Education.
The clinical logic with which her name is firmly associated in stone disease aligns well with current recommendations: stenting should be meaningful and targeted. For practice, this means a simple conclusion: in a patient with a stone and complicated obstruction, a stent can be lifesaving, but after uncomplicated ureteroscopy, routine stenting should not remain an inertial habit. [100] [101] [102]

Olivier Traxer, Professor of Urology, Director of the Urology Department at Tenon Hospital, Sorbonne University, Paris, and Director of the Clinical Research Group on Urolithiasis, is a professor at the University of Paris.
His professional biography reflects modern endourology in its most practical form: precise technique, flexible ureteroscopy, and the judicious use of guidewires and stents. The key message is that a good stent is not simply a "tube inserted" but rather part of a strategy in which the indications, technique for passing the obstruction, the correct length, the duration of insufficiency, and the removal plan are all equally important. [103] [104] [105]

Bhaskar Somani, Professor of Urology, Consultant Urologist at University Hospital Southampton, is a leading specialist in endourology and ureteroscopy.
His clinical practice is particularly well-aligned with the modern approach to assessing patient quality of life after surgery. Not only the success of stone removal, but also the severity of stent symptoms, the length of stent life, and whether it can be safely avoided are now becoming part of the treatment outcome. This is why modern endourological solutions are increasingly aimed at minimizing unnecessary stenting and reducing the duration of stent insufficiency. [106] [107] [108]

Conclusion

Ureteral catheterization today is not a single standard procedure, but a whole range of solutions for restoring urine flow. In emergency situations, it helps save the kidney and reduce the risk of sepsis; in elective situations, it supports the ureter after surgery or bypasses a stricture or compression; and in diagnostic situations, it clarifies anatomy and performs contrast. Its value is determined not by the actual placement of the catheter, but by the accuracy of the readings and the correct choice between a short catheter, an internal stent, and a nephrostomy. [109] [110]

Based on current recommendations, the most reasonable practical conclusion is as follows: in the case of infected obstruction, drainage should be performed urgently; after uncomplicated ureteroscopy, a routine stent is not necessary for everyone; and once a stent is in place, the physician and patient should understand in advance how long it will last, what symptoms are expected, and which signs require re-examination without delay. It is precisely this approach that makes ureteral catheterization truly modern and safe today. [111] [112] [113]