What are the potential complications of shockwave therapy?

Complications of Shockwave Therapy

Shockwave therapy is generally safe with low complication rates, but clinicians must counsel patients about potential adverse events including pain, hematoma formation, skin reactions, and rare but serious complications such as tendon rupture.

Common Complications (Minor - Clavien Grade I-II)

Urological Applications (ESWL for Kidney Stones)

• Pain and discomfort occur in approximately 12.1% of patients during or after treatment 1
• Macroscopic hematuria develops in 17.2% of patients, typically self-limiting 1
• Steinstrasse (stone street obstruction) occurs in 4% of cases when stone fragments accumulate in the ureter 1
• Renal colic affects 2-4% of patients as fragments pass 1
• Bacteriuria develops in 7.7-23% of non-infected stone cases 1

Musculoskeletal Applications

• Local pain and swelling at the treatment site are common and typically transient 2
• Skin redness may occur at the application site 3
• Petechiae or bruising can develop from capillary disruption 4

Serious Complications (Major - Clavien Grade III-IV)

Urological ESWL

• Clinically significant perinephric hematoma occurs in 0.21% of cases, with asymptomatic hematoma in 1.2% 1
• Sepsis develops in 0.15% of patients, particularly those with infected stones 1
• Cardiovascular dysrhythmias occur in 11-29% of patients, especially those with pacemakers or defibrillators 1
• Higher bleeding risk exists with second and third-generation lithotripters due to increased power density and smaller focal zones 1

Musculoskeletal ESWT

• Tendon rupture is a rare but documented complication, with at least one case report of Achilles tendon tear following ESWT for calcific tendinopathy 3
• Bone injury has been reported in rare cases 5

Risk Factors and High-Risk Scenarios

Absolute Contraindications for ESWL

• Pregnancy is an absolute contraindication 1
• Bleeding disorders preclude safe treatment 1
• Uncontrolled urinary tract infection must be treated first 1
• Arterial aneurysm near the treatment site poses rupture risk 1

Relative Contraindications and Cautions

• Anticoagulation therapy significantly increases bleeding risk; ESWL is classified as a high-risk bleeding procedure 1
• Patients on warfarin require bridging with LMWH rather than continuing warfarin during perioperative period 1
• Severe obesity may limit effective treatment 1
• Skeletal malformations can prevent proper positioning 1

Specific Complications by Application

Peyronie's Disease Treatment

• ESWL does not effectively reduce penile curvature or plaque size and should not be used for these indications 1
• May provide pain relief but poses "substantial patient burden" with questionable overall utility 1
• The AUA guideline specifically recommends against using ESWL for curvature or plaque reduction (Moderate Recommendation, Grade B) 1

Stone Disease Management

• Residual stone fragments occur more frequently with ESWL than percutaneous nephrolithotomy, with regrowth rates of 21-59% 1
• Need for auxiliary procedures ranges from 6-9% 1
• Multiple treatment sessions may be required, increasing cumulative morbidity and cost 1

Strategies to Minimize Complications

Technical Modifications

• Slower shockwave rate (60-90/min instead of 120/min) improves stone-free rates and reduces tissue damage 1
• Stepwise energy ramping minimizes renal injury 1
• Proper acoustic coupling between treatment head and skin is crucial to prevent shockwave deflection 1
• Low-energy pretreatment induces vasoconstriction that limits subsequent parenchymal injury 1

Pharmacologic Adjuncts

• Allopurinol (free radical scavenger) has been shown to reduce renal damage from shockwave-induced oxidative stress in both animal models and humans 1

Long-Term Concerns

• The relationship between ESWL and hypertension or diabetes remains unclear, with no conclusive evidence of long-term adverse effects to date 1
• Cardiovascular effects require monitoring, particularly in patients with pre-existing cardiac conditions 1

Clinical Pitfall to Avoid

The most critical error is using ESWL for inappropriate indications where it is ineffective (such as Peyronie's disease curvature reduction) or when safer, more effective alternatives exist 1. Additionally, failing to screen for bleeding disorders or manage anticoagulation appropriately can lead to serious hemorrhagic complications 1.