An infected blocked kidney is an emergency—not a routine RIRS appointment
Seek Urgent Medical Care If
- You have fever, chills or feel markedly unwell with flank pain or a known urinary stone.
- You are passing very little or no urine, particularly with one functioning kidney or stones affecting both sides.
- Pain or vomiting is severe and persistent, or you cannot keep fluids down.
- You become confused, faint, breathless or rapidly worse.
When infection is trapped behind an obstruction, the immediate priority is drainage—usually with a ureteric stent or nephrostomy—and stabilization. Definitive laser treatment is normally delayed until the infection has settled.
What Is RIRS?
Retrograde means travelling upward against the normal direction of urine flow. Intrarenal means inside the kidney. During RIRS, a flexible ureteroscope passes through the urethra into the bladder, then up the ureter and into the kidney’s collecting system.
The surgeon directly sees the stone on a monitor. A fine laser fibre can reduce it to dust-like particles or divide it into retrievable fragments. Small fragments may be removed with a basket, while others are expected to clear naturally after surgery.
RIRS and flexible ureteroscopy usually describe the same renal-stone pathway
“URS” is a broad term for ureteroscopy. A rigid or semi-rigid scope is commonly used for ureteric stones, while a flexible scope can bend into the kidney and is often described as RIRS or flexible ureterorenoscopy.
When May RIRS Be Considered?
RIRS may be offered when active treatment is appropriate and a retrograde endoscopic route is likely to provide a reasonable balance of clearance and risk.
Symptomatic renal stone
Persistent pain, repeated colic or bleeding attributable to a stone may justify active treatment.
Growth or obstruction
A growing stone, impaired drainage or risk to kidney function may change observation into intervention.
Selected moderate stone burden
RIRS is commonly considered for selected renal stones below about 20 mm, but total volume and anatomy matter more than one number alone.
Lower-pole stone
Endoscopic treatment may be useful when lower-pole anatomy makes fragment clearance after shock-wave treatment less reliable.
Multiple stones
Selected stones in more than one calyx may be reachable in the same procedure, although larger total burden can require staging.
After another treatment
RIRS may treat residual fragments or a stone that did not clear with observation or shock-wave treatment.
When Might Another Approach Be Better?
The choice is individualized. RIRS may not be the most efficient or safest first option when:
- The total stone burden is above about 20 mm or the stone is staghorn-shaped; PCNL generally offers more complete clearance in fewer sessions.
- A small uncomplicated stone can reasonably be observed with planned imaging.
- Stone size, position and density make shock-wave treatment an appropriate less-invasive alternative.
- Urinary infection, untreated obstruction or unstable illness makes definitive surgery unsafe at that time.
- The ureter is too narrow or difficult to enter safely during the planned procedure.
- Complex anatomy, previous reconstruction or a non-functioning kidney requires a different strategy or higher-centre care.
For a large stone, RIRS may still be selected when PCNL is unsuitable, but the patient should understand that two or more planned sessions may be required.
How Is the Procedure Chosen?
What Happens Before RIRS?
- Imaging review: CT is commonly used to map stone size, position, density and anatomy. Earlier scans may need updating if symptoms or timing have changed.
- Urine assessment: Urine culture or microscopy checks for infection before stone surgery.
- Blood tests: Kidney function, blood count and clotting assessment may be required.
- Anaesthetic assessment: Medical conditions, allergies, previous anaesthetic problems and fitness are reviewed.
- Medication review: Bring a complete list. Never stop blood-thinning or other regular treatment without a written plan from the responsible clinicians.
- Fasting instructions: Follow the exact hospital instructions rather than a generic online timetable.
- Consent: Discuss alternatives, the chance of a stent, failed access, residual fragments and staged surgery.
What Happens During RIRS?
Access Sheath, Pre-Stenting and Failed Access
A ureteric access sheath is a temporary working channel placed through the ureter during selected procedures. It can permit repeated entry, improve outflow and visibility, and help control pressure inside the kidney. It is not required in every case and must not be forced if resistance makes insertion unsafe.
Some patients already have a stent before RIRS because the kidney was obstructed or infected. In others, a narrow ureter prevents safe entry on the first attempt. The safer choice may be to place a stent, allow the ureter to relax and return for RIRS later. This is a staged safety strategy—not a surgical failure.
Dusting, Fragmentation and Basket Retrieval
Dusting uses laser settings intended to create very small particles that can clear with urine. Fragmentation divides the stone into larger pieces that may be removed with a small retrieval basket. Surgeons may combine both approaches according to the stone and visibility.
“Dust” is not the same as a guaranteed empty kidney. Some particles or fragments can remain, especially with larger or multiple stones. Follow-up imaging is needed to determine the true residual burden.
Will I Need a Ureteric Stent?
A stent is a soft internal tube running from the kidney to the bladder. It may be used when there is ureteric swelling or injury, residual stone, infection risk, difficult access, bleeding, uncertainty about drainage or a planned second procedure. Some uncomplicated procedures do not require one.
A stent can cause urinary frequency, urgency, blood in urine, bladder discomfort or kidney-area pain during urination. Before discharge, obtain a clear written plan stating:
- whether a stent was inserted;
- whether it has an external removal string;
- when and how it will be removed or exchanged; and
- which symptoms require earlier review.
A stent must not be forgotten
Do not pull a removal string unless the treating team has specifically instructed you to do so. Contact the hospital promptly if the stent seems displaced or the planned removal date is unclear.
What Should I Expect After Surgery?
Patients are observed until they are awake, stable and able to pass urine appropriately. Many can leave on the same day or after a short stay, while infection risk, bleeding, pain, medical conditions or a complex procedure may require longer observation.
Temporary burning, urinary frequency, mild blood staining and kidney or bladder discomfort can occur, particularly with a stent. These should generally improve rather than steadily worsen. Discharge instructions should specify activity, driving, bathing, work, fluid intake, prescribed treatment and follow-up.
After RIRS
Contact the Hospital Urgently If
- You develop fever, chills, confusion or feel progressively unwell.
- Pain becomes severe, is not controlled by the prescribed plan or is accompanied by persistent vomiting.
- You cannot pass urine or the amount falls markedly.
- Bleeding becomes heavy, large clots appear or faintness develops.
- A stent string or stent appears displaced, or you accidentally remove it.
- Symptoms worsen rather than improve, even without fever.
Possible Risks and Limitations
Residual stone
Some stone may remain and need observation, another RIRS session, shock-wave treatment or PCNL.
Failure to reach the stone
A narrow or difficult ureter may require temporary stenting and another attempt.
Infection and urosepsis
Bacteria can enter the bloodstream despite appropriate precautions; urgent treatment may be required.
Ureteric injury
Abrasion, bleeding or perforation may require longer stenting or drainage. Major injury is uncommon.
Later stricture
Scar narrowing can occasionally develop and obstruct drainage, requiring further assessment or treatment.
Bleeding or retention
Persistent bleeding, clots or difficulty urinating can require observation, catheterization or another procedure.
There are also anaesthetic risks and patient-specific risks related to medical conditions, infection, pregnancy, bleeding tendency, abnormal anatomy or previous urinary surgery. Your consent discussion should reflect your individual risk rather than a generic list alone.
What Does “Stone-Free” Mean?
Stone-free status depends on which scan is used, when it is performed and what fragment size is counted. An operation note describing good fragmentation is not the same as follow-up imaging confirming complete clearance.
The report should document the stone treated, whether access was complete, any residual fragments, whether a stent was inserted and the follow-up plan. Larger, multiple or lower-pole stones are more likely to need staged treatment or surveillance of residual fragments.
RIRS, URSL, Shock-Wave Treatment and PCNL
Recovery and Follow-Up
- Follow the individualized discharge plan for fluid intake, activity, driving and return to work.
- Gentle movement is usually encouraged when safe, but strenuous activity should wait until the treating team’s advised timeframe.
- Keep the stent-removal or exchange appointment and confirm it before leaving the hospital.
- Attend planned imaging even if symptoms have settled; silent residual obstruction or fragments cannot be excluded by comfort alone.
- Submit retrieved stone material for analysis when requested.
- Discuss recurrence prevention after recovery; recurrent, bilateral, unusual or high-risk stones may warrant blood tests and urine-based metabolic assessment.
Common Operation and Report Terms
Flexible ureterorenoscopy
Inspection of the ureter and kidney with a bendable telescope.
Retrograde pyelogram
Contrast imaging performed from the bladder upward to outline the ureter and collecting system.
Ureteric access sheath
A temporary working channel used during selected flexible procedures.
Laser lithotripsy
Fragmentation or dusting of a urinary stone using laser energy delivered through a fine fibre.
Basket extraction
Removal of selected stone fragments with a small retrieval device.
Residual fragment
Stone material remaining after the procedure and requiring follow-up or further treatment.
JJ or DJ stent
A temporary internal drainage tube with curled ends in the kidney and bladder.
Second-look RIRS
A planned later procedure to treat remaining stone burden.
Common Myths
Frequently Asked Questions
What does RIRS stand for?
RIRS means retrograde intrarenal surgery: endoscopic treatment performed by travelling through the natural urinary passage into the kidney.
Is RIRS the same as flexible ureteroscopy?
They usually describe the same flexible endoscopic route when the target is inside the kidney. Ureteroscopy is the broader family of procedures.
Does RIRS require a skin incision?
A standard RIRS procedure does not. Instruments pass through the urethra, bladder and ureter.
Which stone sizes can be treated?
RIRS is commonly considered for selected stones below about 20 mm, but number, total volume, location, density and anatomy are equally important. Larger stones may require PCNL or staged RIRS.
Why do I need a urine test before surgery?
Stone surgery through infected urine can cause severe systemic infection. Infection must be identified and managed before definitive treatment.
Why might the surgeon stop without treating the stone?
If the ureter is too narrow or access is unsafe, forcing the scope could cause injury. Temporary stenting followed by a later procedure is often safer.
Will every stone fragment be removed?
Not always. Some are basketed, while very small particles may be left to clear. Follow-up imaging determines the residual burden.
Will I definitely have a stent?
No. A stent is common but not mandatory after every uncomplicated procedure. The decision depends on drainage, swelling, injury, residual fragments, infection risk and future plans.
How is a stent removed?
It may be removed using an external string when specifically planned, or by a brief telescopic procedure. Obtain the exact date and method before discharge.
Can a stent cause pain and urinary urgency?
Yes. Kidney-area discomfort during urination, bladder irritation, frequency, urgency and blood staining can occur. Severe or worsening symptoms still require review.
Can RIRS be completed in one session?
Often, but not always. Large, multiple, hard-to-reach or complex stones may require a planned second stage or another treatment.
How soon can I return to work?
It depends on anaesthesia, the operation, stent symptoms and the physical demands of your job. Use the individualized discharge advice rather than a fixed online timetable.
How will I know whether I am stone-free?
Your urologist will arrange suitable follow-up imaging. Symptoms and urine colour alone cannot confirm complete clearance.
Can the same stone return after RIRS?
Residual fragments can grow, and new stones can form. Stone analysis and recurrence-prevention assessment are therefore important.
When is higher-centre referral appropriate?
Complex staghorn burden, difficult anatomy, failed access, major ureteric injury, unusual stone disease, reduced kidney function or a need for combined or advanced procedures may require specialist higher-centre care.