Flexible Ureteroscopy + Holmium Laser

A thin, steerable telescope is passed through the urethra and bladder, up the ureter and into the kidney. A Holmium:YAG laser fibre inside the scope fragments the stone into small pieces or fine dust that pass in the urine. No external incisions.

At a glance

Key points

  • What it is: a flexible endoscopic operation under general anaesthetic - scope up through the natural urinary passages, Holmium:YAG laser lithotripsy of the stone, no external cuts.1,2,7
  • Who it is for: ureteric stones unlikely to pass (usually above 6 mm); kidney stones up to about 2 cm; diagnostic inspection and biopsy of the upper urinary tract.1,2,7
  • Stone-free rate: around 82 per cent overall in the 2025 EAU Endourology Section meta-analysis of 146,845 patients; retreatment around 11 per cent.5
  • Sessions: most patients are stone-free in a single sitting; a minority need a second, usually shorter, procedure for residual fragments.1,2,5
  • Main risks: blood in the urine for 1–2 days, stent symptoms (around 80 per cent of stented patients), urinary infection (3–5 per cent), ureteric perforation (1–2 per cent), avulsion (below 0.5 per cent), long-term stricture (0.5–1 per cent), residual fragments in a minority of cases.1,2,8,9
  • When it is not the right choice: stones above approximately 2 cm or stag-horn stones (PCNL preferred); uncontrolled urinary-tract infection; uncorrected coagulopathy; impassable distal obstruction.1,2
  • Anaesthesia: general anaesthetic, day case or a single overnight stay.1,2

What is flexible ureteroscopy with Holmium laser?

A ureteroscope is a thin, flexible telescope with fibre-optic vision that can be steered up the ureter into the kidney. A Holmium:YAG laser (often shortened to "Holmium laser") passes down a narrow working channel in the scope and breaks the stone into tiny fragments or dust, which are then flushed out or retrieved with a fine wire basket. Because the scope passes through the body's natural urinary passages, there are no external cuts.7

A modern flexible ureteroscope is typically 7 to 9 French at the tip (2.3 to 3.0 mm), with:

  • A deflectable tip that can bend up to approximately 270 degrees in each direction, so the whole of the inside of the kidney (renal pelvis, upper pole, interpolar and lower pole calyces) can be inspected and treated.7
  • A single working channel that accepts a laser fibre (200 to 272 micron core typically), a stone basket, or biopsy forceps.7
  • Continuous saline irrigation, a small high-resolution camera and a light fibre.7

The Holmium:YAG laser works at a wavelength of approximately 2,100 nanometres, which is strongly absorbed by water and by the stone surface. Short laser pulses cause the stone to fragment into small pieces (traditional "fragmentation" with larger-setting long pulses) or into fine dust (newer "dusting" strategy with high-frequency, lower-energy short pulses). Both strategies are effective; dusting tends to reduce the need for basket retrieval and is now the more common approach for stones within the kidney.1,2,11

See Rigid Ureteroscopy for the rigid (semi-rigid) companion procedure, Shockwave Lithotripsy (ESWL) for the non-invasive alternative, and Kidney Stones for how flexible ureteroscopy fits into the wider menu of stone treatments.

Dusting versus fragmentation

Both are done with the same laser but with different settings:

  • Dusting uses high-frequency (30 to 80 Hz), lower-energy (0.2 to 0.5 J) pulses to reduce the stone to very fine particles that are small enough to pass spontaneously in the urine. Dusting tends to be faster for large intrarenal stones and avoids repeated basket extractions.11
  • Fragmentation uses lower-frequency (8 to 15 Hz), higher-energy (0.8 to 1.5 J) pulses to split the stone into basketable pieces. Fragmentation is useful when a representative stone sample is wanted for analysis, when the stone is in the ureter, and when complete clearance needs to be confirmed endoscopically.11

In practice the two are combined within a single procedure, depending on stone size, location and composition. EAU 2025 and AUA 2026 guidelines endorse both strategies as acceptable.1,2

Holmium:YAG versus thulium fibre laser

The thulium fibre laser (TFL) has emerged over the last few years as an alternative to Holmium:YAG for stone lithotripsy. Contemporary meta-analyses (Ulvik 2022, Kwok 2022, Jiang 2023) show:

  • Stone-free rates are similar between Holmium:YAG and TFL in most studies.11
  • TFL typically achieves shorter fragmentation times per unit stone mass and produces a finer dust at comparable settings.11
  • Complication rates are similar; TFL fibres are smaller and the laser unit is quieter and cheaper to run, at the cost of a less mature evidence base.11

Holmium:YAG remains the most widely available laser for stone lithotripsy in Australia at the date of writing and is the laser used in most Sydney theatres. The choice of laser has no clinically important effect on the procedure description, recovery, or risks from the patient's perspective.11

Ureteral access sheath

A ureteral access sheath (UAS) is an optional thin-walled tube placed over a guidewire in the ureter at the start of a flexible ureteroscopy. It allows the flexible scope to be passed up and down the ureter multiple times without repeated trauma to the ureter, maintains lower intrarenal pressures during irrigation, and eases the removal of basketed fragments.1,7 A sheath is used selectively - particularly for larger stones that need multiple basketings, for stag-horn assisted procedures, and in settings where intrarenal pressure matters (obstructed kidney, solitary kidney). Its use is not mandatory; EAU 2025 and AUA 2026 describe its role without recommending it routinely, and the decision is made per case.1,2

When flexible ureteroscopy with laser is recommended

Ureteric stones that are unlikely to pass

For ureteric stones too large to pass spontaneously (usually above 6 mm) or causing ongoing pain, obstruction or infection, flexible ureteroscopy is an acceptable first-line option. For proximal ureteric stones smaller than 2 cm and mid-ureteric stones, either ESWL or ureteroscopy is acceptable (EAU 2025 and AUA 2026 aligned).1,2

Kidney stones up to approximately 2 cm

For lower-pole kidney stones smaller than 1 cm, flexible ureteroscopy, ESWL, or PCNL are all acceptable first-line options (AUA 2026 Statement 17: Expert Opinion; EAU 2025 aligned).1,2 For non-lower-pole kidney stones up to 2 cm, flexible ureteroscopy is a reasonable first-line option.1,2 For stones under 1 cm specifically, ESWL and flexible ureteroscopy perform similarly on stone-free rate; for stones 1 to 2 cm, flexible ureteroscopy gives a higher stone-free rate (Lv 2022 meta-analysis, 17 studies, 2,265 patients, OR 2.00 for 1-2 cm subgroup, 95% CI 1.29-3.12).4

After failed shockwave lithotripsy

When ESWL has failed twice, AUA 2026 recommends offering ureteroscopy rather than continuing with further ESWL (Evidence Level Grade C).2

Stones that are unlikely to respond to ESWL

  • Hard stones (density above approximately 1000 Hounsfield units on CT).1
  • Stones that cannot be reliably imaged on fluoroscopy (uric acid, cystine) - endoscopic visualisation with the flexible ureteroscope side-steps this issue.1
  • Lower-pole kidney stones in a kidney with unfavourable infundibulopelvic anatomy.1

Patients who need a single-session stone-free result

For patients who need to return to work or travel soon after treatment, flexible ureteroscopy is often preferred because the single-session stone-free rate is higher than with ESWL (Nedbal 2025: 82.2 per cent vs 64.4 per cent; retreatment 10.6 per cent vs 29.4 per cent).5

Patients on anticoagulation that cannot be interrupted

Flexible ureteroscopy can usually be performed on therapeutic anticoagulation, whereas ESWL is generally contraindicated on uninterrupted anticoagulation and PCNL requires a controlled coagulation status. EAU 2025 and AUA 2026 both name flexible ureteroscopy as the preferred intervention in this setting.1,2

Diagnostic and biopsy cases

Flexible ureteroscopy is used to inspect the renal pelvis and calyces, take biopsies or brushings of suspected upper-tract urothelial tumours, and perform retrograde ureteropyelograms when CT urography or MR urography is equivocal.1,7

When flexible ureteroscopy is not the preferred choice

Stone factors

  • Very large (>2 cm) stones or stag-horn stones - PCNL, with supplementary flexible ureteroscopy as needed, is usually preferred. AUA 2026 Statement 19 specifically notes that PCNL is associated with a higher stone-free rate than either ESWL or ureteroscopy for lower-pole kidney stones larger than 1 cm (Strong Recommendation; Evidence Level Grade A).1,2
  • Impassable distal obstruction - if a distal stricture or impacted stone cannot be negotiated with a safety guidewire, ureteroscopy cannot be completed in that sitting; a stent or nephrostomy is placed first and the procedure is staged.1

Patient factors - absolute contraindications

  • Uncontrolled urinary-tract infection. Instrumenting an infected system risks urosepsis. The infection is treated first.1,2
  • Uncorrected coagulation disorder. Active bleeding diatheses require correction before instrumentation.1,2

Patient factors - relative considerations

  • Severe pelvic reconstruction or urinary diversion can complicate access. Pre-operative imaging is reviewed carefully and a collaborative plan is made with reconstructive colleagues.1
  • Pregnancy. Ureteroscopy with laser lithotripsy is the preferred active stone treatment in pregnancy when intervention is required, because ESWL is contraindicated and PCNL is unsafe. Careful radiation avoidance and joint care with an obstetric anaesthetist are standard.1

How Dr Kooner performs it

Under general anaesthetic, after confirmation of a sterile urine culture or appropriate antibiotic prophylaxis:

  1. Cystoscopy. A small cystoscope is passed into the bladder to check the ureteric opening.7
  2. Safety guidewire. A guidewire is carefully advanced into the kidney under X-ray guidance; this wire is left in throughout the case as a "safety wire".7
  3. Ureteral access sheath (selectively). For larger stones or cases needing multiple scope passes, a ureteral access sheath is placed over the guidewire; for smaller intrarenal stones no sheath is used.1,7
  4. Flexible ureteroscope. The flexible ureteroscope is passed up over the wire (or through the access sheath) until the stone is in view.7
  5. Laser lithotripsy. The stone is fragmented with the Holmium:YAG laser into dust (high-frequency, low-energy) or into small pieces (lower-frequency, higher-energy), as appropriate.1,2,11
  6. Retrieval. Fragments are retrieved with a basket where needed, or allowed to wash out through the natural passages.7
  7. Stent. A temporary ureteric stent is usually placed for 1 to 2 weeks to let the ureter settle, particularly if instrumentation has been prolonged or if there is any mucosal swelling. Selective omission is appropriate for shorter, uncomplicated cases without ureteric injury.1,2,8
  8. Wake and transfer. The patient is woken in theatre and moved to recovery.

Intra-operative fluoroscopy is used sparingly and with appropriate shielding. Stone fragments are sent for mineralogical analysis; stone composition guides medical prevention and is strongly supported by EAU 2025 for all first-time stone-formers and for patients with recurrent stones.1

Your journey - what to expect

  1. Before

    Planning

    A non-contrast CT of the urinary tract confirms stone size, location, density and absence of distal obstruction. A urine culture confirms no active infection. Anticoagulant or antiplatelet medication is reviewed with the prescribing physician - ureteroscopy can often be performed on therapeutic anticoagulation. Standard fasting is 6 hours before the procedure (clear fluids usually allowed up to 2 hours before).1,2,10

  2. Day of surgery

    The procedure

    Admission 2–3 hours before the operation. Antibiotic prophylaxis is given per EAU/AUA recommendations. The procedure itself typically takes 30 to 90 minutes depending on stone burden and whether a combined rigid plus flexible approach is used.1,2

  3. Same day – next morning

    Going home

    Most patients go home the same day or the following morning after a short recovery period. Do not drive, operate machinery, sign important documents or drink alcohol for 24 hours after a general anaesthetic, and arrange a responsible adult to accompany you home.1,2,8,10

  4. 1–2 weeks

    Living with the stent

    If a stent has been left in place, expect some urinary urgency, frequency, a sensation of incomplete emptying, and mild flank pain when passing urine. Around 80 per cent of stented patients report at least one stent-related symptom; symptoms resolve rapidly after the stent is removed.1,2,8

  5. 1–2 weeks

    Stent removal

    The stent is removed in a brief clinic appointment using a flexible cystoscope, usually under local anaesthetic gel. See Ureteric Stents for practical advice.8

  6. 4–6 weeks

    Follow-up imaging

    An imaging check (ultrasound or low-dose CT) confirms full stone clearance and good drainage.1,2

Evidence and outcomes

Stone-free rate

  • The largest contemporary pooled estimate comes from the 2025 EAU Endourology Section systematic review and meta-analysis by Nedbal, Geraghty and colleagues (22 studies, 146,845 patients): ureteroscopy stone-free rate 82.2 per cent, ESWL 64.4 per cent (p<0.001); retreatment 10.6 per cent vs 29.4 per cent.5 Stone-free rates vary with stone size, location and density, so the individual figure will vary.
  • For stones 1 to 2 cm, flexible ureteroscopy gives a higher stone-free rate than ESWL (Lv 2022 meta-analysis, OR 2.00, 95% CI 1.29-3.12); for stones under 1 cm the two modalities perform similarly.4
  • For the difficult subgroup of lower-pole kidney stones 10 mm or less, the UK PUrE RCT 1 reported a stone-free rate of 72 per cent with flexible ureteroscopy versus 36 per cent with ESWL; 12-week health status was not significantly different, and at UK willingness-to-pay thresholds ESWL was the cost-effective option.6

Complications

  • Overall complication rate is in the same broad range as ESWL - around 22 per cent in pooled modern series - though the type of complication differs.5,9
  • Ureteric injury. Any mucosal injury on careful inspection 7 to 10 per cent, with perforation 1 to 2 per cent (usually managed with a stent for 4 to 6 weeks) and avulsion below 0.5 per cent.9
  • Urinary infection in 3 to 5 per cent; fever with systemic infection in around 1 per cent.1,9
  • Ureteric stricture 0.5 to 1 per cent at long-term follow-up.9
  • Stent-related symptoms in approximately 80 per cent of stented patients; resolve rapidly after stent removal.8
  • Serious complications (Clavien-Dindo grade III and above) in around 2 to 4 per cent.9

Australian context - MBS items

  • Item 36833 - flexible ureteroscopy with stone extraction and/or lithotripsy, unilateral.10
  • Item 36821 - rigid ureteroscopy with stone extraction and/or lithotripsy, unilateral (billed when both rigid and flexible scopes are used in the same operation).10
  • Item 36564 - ureteric stent insertion, unilateral.10

Schedule Fees change periodically; the current fee should be verified against MBS Online before a final quote is issued.

Risks and considerations

  • Blood in the urine for 1 to 2 days.1,9
  • Stent-related symptoms in approximately 80 per cent of stented patients.8
  • Urinary infection 3 to 5 per cent; febrile UTI around 1 per cent.1,9
  • Ureteric perforation 1 to 2 per cent.9
  • Ureteric avulsion - rare, below 0.5 per cent.9
  • Ureteric stricture 0.5 to 1 per cent at long-term follow-up.9
  • Residual fragments requiring a second procedure in a minority of cases.5
  • General anaesthetic risks as for any day-case procedure.
Signs to seek urgent medical attention after flexible ureteroscopy. Go to the emergency department without delay if any of the following occurs: fever over 38 °C, shaking chills, or cloudy, offensive urine; pain not controlled by simple analgesia; heavy visible bleeding or passing clots; inability to pass urine; severe or worsening loin pain with nausea and vomiting; new leg swelling, calf pain, or chest pain and breathlessness.

Flexible ureteroscopy + laser at Kidney Surgery Sydney

Dr Raji Kooner performs flexible (and where indicated, rigid) ureteroscopy with Holmium laser lithotripsy at St Vincent's Private Hospital, the Mater Hospital North Sydney, and Bowral District Hospital. Stone composition analysis is arranged on every case, and metabolic testing is offered to any patient with recurrent stones.

Patients with a kidney or ureteric stone, a filling defect on imaging, a suspected upper-tract urothelial carcinoma, or stones that have failed ESWL are welcome to contact the practice to arrange a consultation or request a second opinion.

Frequently asked questions

Does flexible ureteroscopy hurt?

The procedure itself is performed under general anaesthetic, so nothing is felt at the time. Most post-procedural discomfort comes from a temporary stent (urinary urgency, frequency, mild flank ache when urinating) rather than from the laser itself. Simple analgesia, hydration, and a short course of an alpha-blocker or anticholinergic usually control the symptoms.1,2,8

Why is a stent needed?

The ureter often swells after instrumentation, especially after laser treatment of an impacted stone. A soft plastic stent keeps urine flowing from the kidney to the bladder while the ureter settles, preventing a blockage. It is removed 1–2 weeks later.1,2,8 See Ureteric Stents.

Is all the stone removed in one go?

For most small- to moderate-sized stones, yes. For larger or multiple stones, a staged approach (or a switch to PCNL) may be planned. The aim is complete clearance, not just symptom control.1,2,5

How soon can I return to work and exercise?

Most people return to desk-based work within two to three days. Heavy manual work and contact sports are usually avoided while the stent is in place.1,2

How do I stop another stone forming?

Fragments or stone dust are analysed, and prevention advice is tailored to the type of stone and your medical history. Adequate fluid intake is the single most important step. See Kidney Stones - preventing recurrence.1

Is Holmium laser the same as "shockwave"?

No. Holmium:YAG laser is a laser applied to the stone inside the urinary tract via the ureteroscope; shockwave lithotripsy (ESWL) uses shockwaves from outside the body. See Shockwave Lithotripsy (ESWL) for the non-invasive alternative.1,2

What is the difference between Holmium:YAG and the thulium fibre laser?

Both work through the same delivery fibre in the flexible ureteroscope. Holmium:YAG is the established workhorse for stone lithotripsy and is the laser most widely available in Australian theatres at present; thulium fibre laser (TFL) is a newer option with similar stone-free rates and shorter fragmentation times per unit stone mass in contemporary meta-analyses. From the patient's perspective the procedure, recovery and risks are very similar.11

Can I have flexible ureteroscopy if I am on blood thinners?

Often, yes. Ureteroscopy can usually be performed on therapeutic anticoagulation - unlike shockwave lithotripsy, which is generally contraindicated on uninterrupted anticoagulation - but the plan is individualised in consultation with your cardiologist or haematologist.1,2

Will I need a second procedure?

Most patients are stone-free in a single sitting. A minority (around 11 per cent in the pooled 2025 Nedbal/Geraghty meta-analysis) need a second, usually shorter, procedure for residual fragments.5

What if my stone is bigger than 2 cm?

For stones above approximately 2 cm, percutaneous nephrolithotomy (PCNL) is usually the preferred approach, often with a second-look flexible ureteroscopy afterwards. See PCNL (Keyhole Stone Surgery).1,2

Will I stay overnight?

Most patients go home the same day or the following morning. A small proportion stay overnight, usually because the procedure finished late in the day or there was significant ureteric oedema.1,2,8

Related services

Kidney Stones OverviewHow treatment is chosen. Rigid UreteroscopyFor distal and mid-ureteric stones. Shockwave Lithotripsy (ESWL)The non-invasive alternative. PCNLFor larger or stag-horn stones. Ureteric StentsLiving with, and removing, a stent.

References

  1. Skolarikos A (Chair), Geraghty R, Somani BK, Tailly T, Jung H, Neisius A, Petrik A, Kamphuis GM, Davis N, Lardas M, Gambaro G, Sayer JA, Lombardo R, Tzelves L. European Association of Urology Guidelines on Urolithiasis. Eur Urol 88(1):64–75, 2025. DOI 10.1016/j.eururo.2025.03.011. uroweb.org/guidelines/urolithiasis/
  2. Pearle MS, Matlaga BR, Antonelli JA, et al. Surgical Management of Kidney and Ureteral Stones: AUA Guideline (2026). American Urological Association. Three-part series in Journal of Urology: Part I DOI 10.1097/JU.0000000000004842; Part II DOI 10.1097/JU.0000000000004843; Part III DOI 10.1097/JU.0000000000004844. auanet.org
  3. Lv G, Qi W, Gao H, et al. Safety and efficacy of extracorporeal shock wave lithotripsy vs. flexible ureteroscopy in the treatment of urinary calculi: a systematic review and meta-analysis. Front Surg 2022;9:925481. DOI 10.3389/fsurg.2022.925481. doi.org/10.3389/fsurg.2022.925481
  4. Nedbal C, Geraghty R, Somani BK, et al. Cost and effectiveness of flexible ureteroscopy versus shockwave lithotripsy for urolithiasis: a systematic review and meta-analysis by the EAU Endourology Section. Eur Urol Focus, July 2025. PubMed 40634171. pubmed.ncbi.nlm.nih.gov/40634171
  5. Wiseman OJ, Starr K, McClinton S, et al. (PUrE Study Group). The PUrE randomised controlled trial 1: clinical and cost-effectiveness of flexible ureterorenoscopy and extracorporeal shockwave lithotripsy for lower-pole stones of ≤10 mm. Eur Urol 2025. DOI 10.1016/j.eururo.2025.02.002. sciencedirect.com
  6. British Association of Urological Surgeons (BAUS). Diagnostic Ureteroscopy, Ureteroscopy (and laser) for stones in the ureter or kidney, Endopyelotomy (laser), Ureteric stent insertion, and Advice to patients with a ureteric stent - patient information leaflets, current versions accessed April 2026. baus.org.uk/patients/information_leaflets
  7. Joshi HB, Stainthorpe A, MacDonagh RP, Keeley FX Jr, Timoney AG, Barry MJ. Indwelling ureteral stents: evaluation of symptoms, quality of life and utility. J Urol 169(3):1065–9, 2003. Approximately 80% of patients with an indwelling stent experience at least one stent-related symptom; confirmed in the 2019 Tailly systematic review and the 2024 EAU Endourology Section stent-symptom synthesis. pubmed.ncbi.nlm.nih.gov/12576846
  8. de la Rosette J, Denstedt J, Geavlete P, et al. CROES Ureteroscopy Global Study. J Endourol 28(2):131–9, 2014 (11,885 patients). Combined with de Coninck V, Keller EX, Rodriguez-Monsalve M, Traxer O. Complications of ureteroscopy: a complete overview. World J Urol 38(9):2147–66, 2020 (DOI 10.1007/s00345-019-03012-1), and a 2021 ureteric-injury meta-analysis (57 studies, perforation 1.7%, 95% CI 1.3–2.1%). pubmed.ncbi.nlm.nih.gov/24147958 | pubmed.ncbi.nlm.nih.gov/31748964
  9. Commonwealth of Australia, Department of Health. Medicare Benefits Schedule Online (current at April 2026). Items cited on this page: 36833 (flexible URS with stone treatment, unilateral); 36821 (rigid URS with stone treatment, unilateral); 36564 (ureteric stent insertion, unilateral). Standard Australian day-surgery safety guidance applies. Schedule Fees should be re-verified against MBS Online at date of publication. mbs online
  10. Holmium:YAG vs thulium fibre laser - Ulvik O, Aesoy MS, Juliebo-Jones P, Gjengsto P, Beisland C. Thulium fibre laser versus Holmium:YAG for ureteroscopic lithotripsy: a prospective randomised clinical trial. Eur Urol 82(1):73–9, 2022 (DOI 10.1016/j.eururo.2022.02.027). Kwok JL, Ventimiglia E, Traxer O, et al. World J Urol 2022 (DOI 10.1007/s00345-022-04213-x). Jiang H, Liu S, et al. BMC Urol 2023 (DOI 10.1186/s12894-023-01280-z). Pooled findings: similar SFR; shorter fragmentation time per unit stone mass for TFL; similar complication rates. Also covers conventional "dusting" (high-frequency, low-energy) vs "fragmentation" (low-frequency, high-energy) laser-setting strategies. pubmed.ncbi.nlm.nih.gov/35300887

Flexible Ureteroscopy and Laser Patient Information Brochures

Diagnostic ureteroscopy PDF Ureteroscopy for stone(s) PDF Endopyelotomy (laser) PDF Ureteric stent insertion PDF Advice to patients with a ureteric stent PDF

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