Adverse Effects of Extracorporeal Shock Wave Lithotripsy (ESWL)

Classification of Adverse Effects by Severity

• The European Association of Urology reports that ESWL has fewer complications than percutaneous nephrolithotomy or ureteroscopy, with most adverse effects being mild (Clavien grade I-II in 18.43% of cases) and managed conservatively, though serious complications (Clavien grade III-IV) occur in 2.48% of patients 1
• Macroscopic hematuria develops in 17.2% of cases 1
• Steinstrasse (stone street formation) occurs in 4-24.2% of patients 1
• Renal colic affects 2-4% of patients 1
• Residual fragment regrowth occurs in 21-59% of cases 1
• Medical expulsive therapy (MET), mechanical percussion, and diuretics can enhance stone passage and reduce analgesic needs 1
• Routine pre-stenting before ESWL does not improve stone-free rates but may reduce steinstrasse formation 1

Infectious Complications

• Bacteriuria develops in 7.7-23% of patients with non-infected stones 1
• Sepsis is rare at 0.15% 1
• Perioperative antibiotic prophylaxis should be offered to all patients undergoing ESWL 2
• The choice of antibiotic prophylaxis should be tailored to institutional or regional antimicrobial susceptibility patterns 2

Tissue-Related Complications

• Asymptomatic hematoma occurs in 1.2% of cases 1
• Symptomatic hematoma develops in 0.21% of patients 1
• A decline in kidney function has been reported in small case series, particularly in children with primary hyperoxaluria, though this may reflect the natural disease course rather than ESWL-specific injury 3
• Cardiac dysrhythmias occur in 11-29% of patients 1

Risk Mitigation Strategies

• Decreasing shockwave frequency from 120 to 60-90 shockwaves per minute improves stone-free rates and reduces tissue damage 1
• Stepwise energy ramping minimizes renal injury 1
• Proper acoustic coupling between the treatment head and skin is crucial, as air pockets can deflect shockwaves 1
• Operator experience significantly impacts outcomes; better results are observed when ESWL is performed by experienced clinicians with precise imaging control 1

Special Populations and Contraindications

• Pregnancy is an absolute contraindication for ESWL 1
• Bleeding disorders are an absolute contraindication for ESWL 1
• Uncontrolled urinary tract infection is an absolute contraindication for ESWL 1
• Arterial aneurysm near the stone is an absolute contraindication for ESWL 1
• Anatomic obstructions distal to the stone are an absolute contraindication for ESWL 1
• ESWL is classified as a procedure with high bleeding risk 2
• Patients with bleeding disorders or receiving antithrombotic therapy should be referred to an internist for appropriate therapeutic measures before proceeding 2

Critical Pitfalls to Avoid

• Avoid dehydration in the perioperative period, particularly in patients with primary hyperoxaluria, as even mild dehydration can lead to acute kidney injury 3
• Do not perform routine post-procedure stenting after uncomplicated ESWL, as this may increase morbidity without improving outcomes 1
• Recognize that ESWL has inferior outcomes compared to percutaneous nephrolithotomy for complex stones, particularly in primary hyperoxaluria patients where stone-free rates may be as low as 20-47% 3

Recommended Number of Shocks for Extracorporeal Shock Wave Lithotripsy (ESWL)

Standard Shock Wave Protocols by Stone Location

• The American Urological Association (AUA) guidelines confirm that hundreds or thousands of shock waves are necessary for adequate stone fragmentation, with typical treatment protocols ranging from 2,000-4,500 shocks depending on stone location and size 4, 5, 6

Critical Technical Considerations

• Stone composition, such as harder stones like calcium oxalate monohydrate or cystine, requires more energy and potentially more shocks 4, 5
• The lithotriptor generation, with second and third-generation machines having smaller focal zones, may require more shocks than the original Dornier HM-3 4, 5

Management of Hematuria with Blood Clots After Lithotripsy

Initial Assessment and Monitoring

• Hematuria with blood clots after lithotripsy is an expected complication occurring in approximately 17% of patients and typically requires conservative management with hydration, monitoring, and delayed resumption of anticoagulation if applicable, according to the European Association of Urology 7
• Reassure the patient that macroscopic hematuria is a common post-lithotripsy finding occurring in 17.2% of cases and usually resolves with conservative measures, as recommended by the European Association of Urology 7

Conservative Management Protocol

• Provide adequate analgesia for discomfort during fragment passage, which occurs in approximately 12% of patients, as suggested by the European Association of Urology 7
• Consider alpha-blockers (medical expulsive therapy) to enhance stone passage and reduce colic episodes, as recommended by the European Association of Urology 7

Anticoagulation Management

• If the patient is on anticoagulation, delay resumption for at least 24 hours postoperatively or until bleeding has almost completely subsided, according to the American Urological Association 8, 9
• LMWH resumption should be delayed at least 24 hours after the procedure or longer if significant bleeding persists, as recommended by the American Urological Association 8, 9
• Warfarin can be restarted as early as day 1 postoperatively, but continue LMWH bridging until INR reaches therapeutic range on two separate measurements, according to the American Urological Association 8, 9

Steinstrasse Management

• Steinstrasse (stone street formation) occurs in 4% of ESWL cases and may present with persistent hematuria and obstruction, as reported by the European Association of Urology 7
• Continue medical expulsive therapy with alpha-blockers if steinstrasse develops with persistent symptoms, as recommended by the European Association of Urology 7
• Consider mechanical percussion and diuretics if steinstrasse develops with persistent symptoms, as suggested by the European Association of Urology 7
• Auxiliary procedures are needed in 6-9% of cases, according to the European Association of Urology 7

Complications and Management of Extracorporeal Shock Wave Lithotripsy (ESWL)

Overall Complication Rates

Stone‑Related Complications

Infectious Complications

Tissue and Renal Complications

Management of High‑Risk Patients

Indications and Contra‑indications (Evidence‑Based Guidance)

Post‑Procedural Monitoring

Contraindications and Risk Management for Extracorporeal Shock Wave Lithotripsy (ESWL)

Absolute Contraindications

• ESWL must not be performed in patients who are pregnant because shock‑wave exposure can harm the fetus. 12
• Uncorrected bleeding disorders (coagulopathy) are an absolute contraindication due to a markedly increased risk of hemorrhage. 12
• Active, untreated urinary‑tract infection is an absolute contraindication; infection must be resolved before ESWL. 12
• Presence of an arterial aneurysm in the treatment field is an absolute contraindication because shock waves can precipitate rupture. 12
• A downstream anatomic obstruction (distal to the stone) is an absolute contraindication, as it blocks fragment passage and raises complication risk. 12

Relative Contraindications / High‑Risk Scenarios

Antithrombotic Therapy

• ESWL is classified as a high‑bleeding‑risk procedure; patients on antithrombotic agents require individualized pre‑procedural management and referral to internal medicine or hematology for risk stratification. 12

Cardiovascular Considerations

• Cardiac dysrhythmias are observed in approximately 11 %–29 % of patients during ESWL, warranting cardiac monitoring in at‑risk individuals. 13

Anatomical and Technical Limitations

• Severe obesity can impede shock‑wave penetration and accurate stone targeting, potentially rendering ESWL ineffective. 12
• Skeletal malformations may prevent proper patient positioning or delivery of shock waves, limiting the feasibility of ESWL. 12
• Patients with pacemakers or implantable defibrillators can undergo ESWL safely when technical precautions are taken and cardiology coordination is ensured. 12

Procedural Optimisation

• Routine pre‑stenting does not improve stone‑free rates and should be avoided, although it may reduce steinstrasse formation in selected cases. 12
• Adequate acoustic coupling between the lithotripter head and the skin is essential; air pockets degrade shock‑wave transmission and lower efficacy. 12

Patient Populations Requiring Modified Approach

Hypertensive Patients

• Hypertension is a risk factor for post‑ESWL renal hematoma; 46 % of reported hematomas occurred in hypertensive individuals. Close blood‑pressure monitoring after ESWL is advised. 13

Prior ESWL Exposure

• A history of previous ESWL sessions is associated with an increased risk of renal hematoma, necessitating heightened post‑procedure surveillance. (Evidence level not specified)

Clinical Decision‑Making: Situations Where ESWL Is Not First‑Line

• For renal stones larger than 20 mm, percutaneous nephrolithotomy (PCNL) provides superior stone‑free rates and should be preferred over ESWL. [14][15]16
• In cases of obstructing stones with suspected infection, urgent drainage (e.g., nephrostomy or ureteral stent) must be performed before definitive stone treatment to prevent sepsis. [14][15]16
• ESWL should never be performed in the setting of active infection combined with obstruction without prior drainage, as this can precipitate life‑threatening sepsis. [14][15]16