Shockwave Lithotripsy (ESWL)

At a glance

What is shockwave lithotripsy?

Extracorporeal shockwave lithotripsy - usually abbreviated ESWL or SWL - is a non-invasive way of breaking up a stone inside the urinary tract. The word "extracorporeal" simply means "from outside the body". Focused high-energy pulses (shockwaves) are generated by a machine called a lithotripter, travel through the skin and soft tissues without damaging them appreciably, and deposit their energy at the stone, where the sudden pressure change fragments the stone by a combination of direct compression, shear, and microscopic bubble formation at the stone surface (cavitation). The fragments then pass out in the urine over the following days to weeks.^1,3,7

Modern lithotripters use electromagnetic, electrohydraulic, electroconductive or piezoelectric generators to produce the shockwaves. Reported stone-free rates across these generator types are broadly similar; electromagnetic machines tend to be slightly quieter and require slightly less analgesia, which is why most current machines use an electromagnetic generator.¹¹

Unlike ureteroscopy with laser lithotripsy, ESWL does not pass any telescope or instrument into the urinary tract - there is no incision, no general anaesthetic is strictly required, and the bladder, ureter and kidney are not entered. That is the reason ESWL remains attractive for selected patients despite its lower single-session stone-free rate compared with endoscopic alternatives. See Flexible Ureteroscopy + Holmium Laser for the laser-based endoscopic alternative, and Kidney Stones for how ESWL fits into the wider menu of treatment options.

How shockwave lithotripsy works

A typical ESWL session follows a consistent pattern:

1. Preparation. A urine test is performed to rule out infection, and any existing antibiotic prophylaxis is confirmed. Antiplatelet or anticoagulant medication is usually paused in consultation with the patient's cardiologist, unless the bleeding risk of stopping is considered greater than the bleeding risk of continuing - in which case ESWL may not be the preferred option.^1,3
2. Positioning. The patient lies on a specialised lithotripter table. A water-filled coupling cushion is placed in contact with the flank skin over the kidney (or the lower back over the ureter) to allow the shockwaves to travel efficiently into the body.⁷
3. Stone localisation. The stone is targeted using fluoroscopy (low-dose live X-ray) or ultrasound, or both. CT imaging obtained before the procedure is used to confirm that the stone is suitable - its size, density (Hounsfield units), skin-to-stone distance, and location in the kidney or ureter all influence how likely ESWL is to succeed.^2,3,10
4. Delivery of shockwaves. Shockwaves are delivered in a stepwise ramp - starting at a low energy setting and gradually increasing. This "ramping" approach has been consistently shown to reduce the risk of perinephric bleeding without compromising stone-free rate.⁹ A typical session delivers roughly 1,500 to 3,000 shockwaves, depending on stone size and response, at a slow rate (often around one per second, i.e. 60 shocks per minute), which is more effective per shockwave than faster rates and reduces kidney injury.³
5. Completion. The session usually takes about 45 to 60 minutes from the time the shockwaves begin. After a brief period in recovery, the patient goes home the same day with instructions about fluid intake, analgesia, when to expect fragment passage, and when to seek help if complications develop.¹²

Is a ureteric stent needed?

In most patients having ESWL for an uncomplicated kidney or ureteric stone, a ureteric stent is not required. A systematic review and meta-analysis of eleven studies confirmed that routine pre-stenting for uncomplicated ESWL does not improve stone-free rates and adds stent-related symptoms and a second procedure to remove the stent.¹³ Ureteric stents are used selectively - for example, where there is a very large stone burden, a stone in a solitary kidney, pre-existing obstruction causing significant hydronephrosis or fever, or a stone that is causing intractable pain before ESWL can be arranged. Whether or not a stent is used will be discussed in advance for each patient.^1,3,13 See Ureteric Stents for more detail.

Australian context

In Australia, ESWL is an established outpatient procedure listed on the Medicare Benefits Schedule (MBS item 36546, "extracorporeal shock wave lithotripsy (ESWL) to urinary tract and post-treatment care for 3 days, including pre-treatment consultations, unilateral"), which reflects the expectation that a treatment episode is a single out-of-hospital session plus short post-procedure follow-up rather than an inpatient admission.¹²

When shockwave lithotripsy is recommended

Current guidelines support ESWL in the following circumstances.

Stones in the ureter (up to 1 cm distal, up to 2 cm proximal)

For a distal ureteric stone of 10 mm or less and a proximal ureteric stone of less than 2 cm, both ESWL and ureteroscopy are acceptable first-line options (AUA 2026: Conditional Recommendation, Evidence Level Grade B; EAU 2025 aligned).^1,2 Which is chosen depends on stone density, body habitus, local access, patient preference, and whether the patient is on anticoagulants (see below).

Stones in the kidney, less than 1 cm

For lower-pole kidney stones smaller than 1 cm, ESWL, ureteroscopy, or percutaneous nephrolithotomy are all acceptable first-line options (AUA 2026 Statement 17: Expert Opinion; EAU 2025 aligned).^1,2 For non-lower-pole kidney stones smaller than 2 cm, ESWL is similarly considered first-line by EAU 2025. For stones under 1 cm specifically, ESWL and flexible ureteroscopy perform similarly on stone-free rate; this is confirmed in the 17-study meta-analysis by Lv and Qi (2022) in which the odds ratio for stone-free rate favoured neither modality in the sub-1 cm subgroup.⁴

Patients for whom a non-invasive option is preferred

ESWL does not require a general anaesthetic in all cases (some centres offer sedation only), does not pass an instrument into the urinary tract, and does not usually require an overnight stay. For selected patients - for example, those with a history of multiple prior endoscopic procedures, patients who wish to avoid a general anaesthetic if possible, and patients with relatively simple, favourable stones - this combination is genuinely attractive.^1,3

Comparative evidence versus flexible ureteroscopy

Across contemporary meta-analyses, flexible ureteroscopy (URS) yields a higher single-session stone-free rate than ESWL, but with more auxiliary procedures avoided per patient and - critically - a lower retreatment rate. The key numbers patients need to understand before choosing are:

• Lv 2022 (17 studies, 2,265 patients): for stones of 1 to 2 cm, flexible URS gave a higher stone-free rate than ESWL (OR 2.00, 95% CI 1.29 to 3.12); for stones smaller than 1 cm, the two modalities performed similarly.⁴
• Nedbal/Geraghty 2025 EAU Endourology Section systematic review (22 studies, 146,845 patients): overall stone-free rate 82.2 per cent for URS versus 64.4 per cent for ESWL (p<0.001); retreatment 10.6 per cent versus 29.4 per cent; overall complication rates were not significantly different (22.6 per cent vs 22.5 per cent). Mean procedural costs were similar (USD 2,546 for URS, USD 2,830 for ESWL).⁵
• PUrE RCT 1 (UK multicentre RCT, 461 patients with lower-pole kidney stones up to 10 mm; 231 flexible URS, 230 ESWL): 12-week health status was not significantly different between flexible ureteroscopy and ESWL (0.807 vs 0.826 on a 0-1 scale); stone-free rate favoured flexible ureteroscopy (72 per cent vs 36 per cent), but at the UK willingness-to-pay threshold of GBP 20,000 per quality-adjusted life-year, ESWL had a 99.9 per cent probability of being the cost-effective option.⁶

These findings are the reason international guidelines continue to list ESWL and flexible ureteroscopy as equally appropriate first-line options for small lower-pole kidney stones and for selected ureteric stones.^1,2 The practical implication for patients is that ESWL will, on average, need more sessions than ureteroscopy to clear the same stone, but it avoids general anaesthetic, endoscopy, and post-operative stent symptoms.

When shockwave lithotripsy is not recommended

Being explicit about who is not a good candidate for ESWL is as important as the list of indications, because choosing the wrong treatment leads to more treatments overall, not fewer.

Stone factors

• Lower-pole kidney stones larger than 1 cm. AUA 2026 Statement 18 advises against ESWL as first-line for these (Expert Opinion). For lower-pole kidney stones larger than 1 cm specifically, AUA 2026 Statement 19 notes that PCNL is associated with a higher stone-free rate than either ESWL or ureteroscopy (Strong Recommendation; Evidence Level: Grade A).²
• Non-lower-pole kidney stones larger than 2 cm. Again, ESWL is not recommended as first-line; PCNL is usually the preferred approach (AUA 2026 Statement 18: Expert Opinion; EAU 2025 aligned).^1,2
• Stag-horn stones. PCNL, with supplementary flexible ureteroscopy as needed, is the standard of care. ESWL alone is insufficient.^1,2
• Very hard stones. High stone density on non-contrast CT predicts poorer ESWL success. The 2023 Garg systematic review of 28 studies and 4,206 patients reported that commonly quoted density cut-offs predicting lower ESWL success lie in the range of about 750 to 1000 Hounsfield units (HU) - stones below that range fragment better, and stones markedly above 1000 HU are less likely to clear in a single session, particularly if larger than 1 cm.¹⁰ Density is only one of several predictors; stone size (under 10 mm is most favourable), skin-to-stone distance, and location also contribute.¹⁰
• Stones that cannot be reliably imaged. Uric acid and cystine stones are sometimes difficult to visualise on fluoroscopy; ultrasound targeting can help but ESWL is less suitable if the stone cannot be clearly seen throughout treatment.³
• Obstruction distal to the stone. If there is an anatomical narrowing downstream of the stone (such as a stricture or a pelvi-ureteric junction obstruction), fragments cannot pass - so ESWL will not achieve stone clearance even if fragmentation succeeds.^1,3

Patient factors - absolute contraindications

• Pregnancy. ESWL is absolutely contraindicated in pregnancy because shockwaves passing through the uterus and developing fetus have not been shown to be safe.^1,3
• Uncorrected coagulation disorders. Active bleeding diatheses substantially increase the risk of perinephric bleeding around the kidney.^1,3
• Arterial aneurysm within the shockwave field. Focused shockwaves can in principle rupture a nearby vascular aneurysm; this is why a pre-procedure CT should be reviewed for an abdominal aortic aneurysm, a renal-artery aneurysm, or a splenic-artery aneurysm in the treatment field.^1,3
• Uncontrolled urinary-tract infection. ESWL on an infected system risks bacteraemia and urosepsis and must be deferred until the infection has been treated.^1,3

Patient factors - relative contraindications

• Anticoagulant or antiplatelet therapy. Patients who cannot safely interrupt anticoagulation are generally better served by flexible ureteroscopy, which does not carry the same perinephric bleeding risk. If ESWL is used at all, the perioperative plan is made jointly with the treating cardiologist or haematologist.^1,2
• Severe obesity. A large skin-to-stone distance (typically above 10 to 12 cm on CT) is associated with lower ESWL success rates, because the shockwave energy attenuates before reaching the stone.^3,10
• Skeletal malformations or other anatomical variants that prevent reliable stone localisation or patient positioning on the lithotripter table.³
• Poorly-controlled hypertension. Hypertension is a dominant modifiable risk factor for perinephric haematoma after ESWL; blood pressure should be controlled before treatment.^3,9

Your journey - what to expect

1. Before

   Planning

   A non-contrast CT confirms stone size, location, density (Hounsfield units), skin-to-stone distance, and absence of obstruction distal to the stone. A urine culture is checked - active infection is treated first. Anticoagulant or antiplatelet medication is reviewed with the prescribing physician. Most centres request fasting for 6 hours before the procedure in case sedation or a light general anaesthetic is used.^1,2,3,10

2. Day of procedure

   The ESWL session

   Arrival is usually two to three hours before the scheduled session. The session itself typically takes 45 to 60 minutes; most patients go home 1 to 2 hours after treatment once any sedation has worn off. Some blood in the urine for a few hours, mild flank bruising and some aching over the treated side are all expected. Do not drive, operate machinery, sign important documents or drink alcohol for 24 hours if sedation or a general anaesthetic has been used, and arrange a responsible adult to accompany you home.^3,12

3. 24–48 hours

   Strain your urine

   Strain the urine through a fine mesh or a fine-pored coffee filter provided by the treating centre. Any fragments caught should be kept dry in a clean container and brought to the follow-up appointment - stone analysis guides medical prevention and is strongly supported by EAU 2025 for all first-time stone-formers and for any patient with recurrent stones.¹

4. 2–6 weeks

   Fragment passage

   Most fragments that are going to pass do so during this window. Intermittent loin-to-groin discomfort is normal and managed with oral analgesia and adequate fluid intake. An alpha-blocker such as tamsulosin may be prescribed for a short period to help fragment passage, particularly for distal ureteric or lower-pole renal fragments.^1,3

5. 4–12 weeks

   Follow-up imaging

   A non-contrast CT, a low-dose CT KUB, or a plain X-ray of the kidneys, ureters and bladder confirms whether the stone is fully clear, whether residual fragments remain, and whether further treatment is needed. If stone-free status has not been achieved, a second ESWL session or a switch to flexible ureteroscopy is discussed. Most courses complete in one or two sessions; a minority need a third. If ESWL has failed twice, AUA 2026 recommends offering ureteroscopy rather than continuing with further ESWL (Evidence Level Grade C).^1,2,3

Evidence and outcomes

ESWL has been in routine clinical use since the early 1980s. The following is a fair, up-to-date summary of what the evidence shows about how well it works and what can be expected.

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: ESWL stone-free rate 64.4 per cent, URS 82.2 per cent (p<0.001). This is an average across a very wide range of stone sizes, locations, and generators, so results for any individual patient will vary.⁵
• Stone-free rate depends strongly on stone characteristics. Stones smaller than 1 cm, in a favourable location (non-lower pole), of density below about 750 to 1000 HU, and at a skin-to-stone distance under about 10 to 12 cm fragment and clear best.¹⁰
• For the difficult subgroup of lower-pole kidney stones 10 mm or less, the UK PUrE RCT 1 reported a stone-free rate of 36 per cent with ESWL versus 72 per cent with flexible ureteroscopy; health status at 12 weeks was not significantly different between the two groups, and ESWL was the cost-effective option at UK willingness-to-pay thresholds.⁶

Retreatment and auxiliary procedures

• Retreatment rate is higher after ESWL than after flexible ureteroscopy. In the Nedbal 2025 systematic review, 29.4 per cent of ESWL patients required retreatment compared with 10.6 per cent after flexible ureteroscopy.⁵ The Lv 2022 meta-analysis reached the same qualitative conclusion for auxiliary procedures.⁴
• When ESWL fails twice, guideline-level advice is to switch to ureteroscopy rather than continue with further ESWL sessions (AUA 2026: Evidence Level Grade C).²

Medical expulsive therapy to help fragment passage

An alpha-blocker such as tamsulosin is commonly prescribed for a short period after ESWL for ureteric and lower-pole kidney fragments. Pooled randomised trial data show that adjunctive tamsulosin after ESWL improves stone-free rate and shortens time to fragment clearance compared with ESWL alone, particularly for distal ureteric fragments and lower-pole renal fragments.^1,3 The guideline support is for selective use rather than routine prescription, and the drug is generally well tolerated (the main side-effects are mild postural dizziness and retrograde ejaculation; the latter is reversible when the drug is stopped).

Complications

• Overall complication rate is in the same broad range as flexible ureteroscopy - around 22 per cent in pooled modern series - though the type of complication differs between the two modalities.⁵
• Haematuria (blood in the urine) is expected for a day or two after ESWL. It is not a complication in that sense - it is an expected physiological consequence of treatment.^1,3
• Steinstrasse (German for "street of stones") is a column of stone fragments forming in the ureter after ESWL. Reported incidence in the literature ranges from around 1 per cent to 23 per cent, depending on stone size, location, and on how aggressively it is looked for; larger renal-pelvis stones (10 to 20 mm) have the highest risk.⁸ About half of steinstrasse cases resolve with conservative management (fluids, analgesia, a course of alpha-blockers); the remainder are usually treated with flexible ureteroscopy and basket extraction.⁸
• Perinephric haematoma (bleeding around the kidney) ranges from around 0.1 per cent clinically apparent to about 30 per cent if CT or MRI is performed routinely in the days after ESWL. The great majority are small, self-limiting and resolve with conservative management; a small minority require blood transfusion, and a very small minority require radiological embolisation. Poorly controlled hypertension is the most important modifiable risk factor: one review reported that uncontrolled hypertension raised clinically relevant haematoma rates from around 0.66 per cent to 3.8 per cent.⁹
• Urinary-tract infection and sepsis. ESWL in the presence of an untreated infection can precipitate bacteraemia or urosepsis; for this reason a pre-procedure urine culture is standard. In routine practice with adequate pre-treatment screening and prophylactic antibiotics, post-ESWL sepsis is uncommon.^1,3
• Bruising of the flank skin is common, particularly with electrohydraulic generators, and self-resolves over a week or two.³

What the evidence does not clearly show

A 2006 Mayo Clinic cohort of patients treated in 1985 reported a higher long-term rate of diabetes and hypertension after ESWL.¹⁴ The claim is still raised by patients and still cited on some patient-information websites. Larger and more recent contemporary cohorts and a 2015 systematic review have not consistently reproduced a clinically important long-term effect on blood pressure or glucose metabolism in unselected patients.¹⁴ The authors of the original Mayo series themselves later published a population-based cohort study that did not find the diabetes association once age, sex and body mass index were accounted for.¹⁴ The practical implication is that a pre-existing tendency to hypertension or diabetes should still be optimised before ESWL, but contemporary evidence does not support refusing ESWL on the basis of this historical signal alone.

Recovery

Recovery from ESWL is usually uncomplicated. The following is a general guide only; the individual post-operative plan will be tailored to each patient.

• Day of procedure. Go home the same day after a short recovery period. If sedation or a general anaesthetic was used, do not drive, operate machinery, drink alcohol, or sign important documents for at least 24 hours; a responsible adult should accompany you home.¹² Expect blood in the urine for 1 to 2 days, mild bruising over the flank, and some aching over the kidney on the treated side.^1,3
• First 24 to 48 hours. Strain your urine through the mesh or filter provided, and save any fragments in a clean dry container for stone analysis at your follow-up appointment.¹
• First week. Drink more fluid than usual (aim for pale-coloured urine roughly every 2 to 3 hours during the day). Intermittent loin-to-groin pain is expected as fragments pass and is usually controlled with simple analgesia. If you have been given an alpha-blocker such as tamsulosin to help fragment passage, continue it as directed.^1,3
• Weeks 2 to 6. Continue normal activity. Most fragments that are going to pass do so in this window.^1,3
• Follow-up imaging. Typically at 4 to 12 weeks after ESWL, depending on stone type and clinical course.^1,3

Shockwave lithotripsy at Kidney Surgery Sydney

Dr Raji Kooner assesses every patient with a kidney or ureteric stone individually and discusses the full range of contemporary options - active surveillance for small, symptom-free stones; medical expulsive therapy for selected ureteric stones; shockwave lithotripsy; flexible ureteroscopy with Holmium laser lithotripsy; and percutaneous nephrolithotomy for larger or more complex stones. The recommended approach is matched to the individual patient after considering stone size, location, density on CT, body habitus, medical comorbidities, current medications (particularly anticoagulants), and patient preference, and in the light of current EAU 2025 and AUA 2026 guideline recommendations.^1,2

Patients with a current kidney or ureteric stone, a stone that has failed a previous treatment, or a history of recurrent stones are welcome to contact the practice to arrange a consultation or request a second opinion.

Frequently asked questions

Related services

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. Published as a 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. Literature search January 2000 to May 2025. auanet.org
3. Zeng G, Zhong W, Chaussy CG, Tiselius HG, Xu C, Turney B, Turk C, Tailly GG, Preminger GM, Akpinar H, Petrik A, Bernardo N, Wiseman O, Farahat Y, Budia A, Jones DK, Suarez EB, De Marco F, Mazzon G, Lv J, Natchagande G, Guven S, Ibrahim TAA, Xu H, Xie L, Ye Z, Sarica K. International Alliance of Urolithiasis Guideline on Shockwave Lithotripsy. Eur Urol Focus, 2023. iaunet.org
4. 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
5. 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
6. 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
7. Manzoor H, Leslie SW. Extracorporeal Shockwave Lithotripsy. StatPearls NBK560887 (last updated 18 October 2024). ncbi.nlm.nih.gov/books/NBK560887
8. Zorzi F, Moretto S, Jannello LMI, Bravo-Balado A, Quarà A, Werth H, Rossin G, Alanazi A, Scilipoti P, Candela L, Liguori G, Doizi S, Traxer O, Panthier F. Understanding steinstrasse: a systematic review of definitions, clinical management, and emerging perspectives in endourology. World J Urol 44:171, 16 February 2026. DOI 10.1007/s00345-026-06267-7. link.springer.com
9. Wong CHM, et al. Risk factors of haematoma after SWL for renal calculi: analysis from randomised controlled trials and a literature review. Int Urol Nephrol 2024. DOI 10.1007/s11255-024-04205-3. PubMed 39292362. link.springer.com
10. Garg M, Johnson H, Lee SM, Rai BP, Somani BK, Philip J. Role of Hounsfield unit in predicting outcomes of shock wave lithotripsy for renal calculi: a systematic review. Curr Urol Rep 24(2):57, February 2023. DOI 10.1007/s11934-023-01145-w. link.springer.com
11. Comparative generator-type data, including the 2022 UP Olomouc comparative study of electrohydraulic, electromagnetic, and electroconductive generators (stone-free rates 85%, 88.9%, 88.2% respectively; analgesia use 20.8% vs 30.6% vs 48.5%, p=0.0005 favouring electromagnetic). biomed.papers.upol.cz
12. Commonwealth of Australia, Department of Health. Medicare Benefits Schedule, item 36546 - Extracorporeal shock wave lithotripsy (ESWL) to urinary tract and post-treatment care for 3 days, including pre-treatment consultations, unilateral. Schedule Fee A$806.55 (Medicare benefit 75% = A$604.95) current as at 1 July 2025; re-verify at date of publication. mbs item 36546
13. Pengfei S, Min J, Jie Y, et al. Use of ureteral stent in extracorporeal shock wave lithotripsy for upper urinary calculi: a systematic review and meta-analysis. J Urol 186(4):1328–35, 2011. PubMed 21855945. pubmed.ncbi.nlm.nih.gov/21855945
14. Krambeck AE, Gettman MT, Rohlinger AL, Lohse CM, Patterson DE, Segura JW. Diabetes mellitus and hypertension associated with shock wave lithotripsy of renal and proximal ureteral stones at 19 years of follow-up. J Urol 175(5):1742–7, 2006. PubMed 16600747. See also D'Addessi A, Vittori M, Racioppi M, et al. (long-term adverse effects of ESWL: systematic review, PubMed 25917723, 2015) and Fankhauser CD, Hermanns T, Lieger L, et al. (Int Urol Nephrol 2018, PMC6013534), both of which did not consistently reproduce the Mayo 2006 associations once age, sex, and body mass index were accounted for. pubmed.ncbi.nlm.nih.gov/16600747