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Extracorporeal Shock Wave Lithotripsy (ESWL)

Advanced Stone Treatment

Key Facts About ESWL

  • ESWL is a noninvasive procedure designed to break apart stones in the urinary system, pancreas, and bile ducts.
  • Shock waves, guided by X-rays or ultrasound, are directed at the stones.
  • Kidney and ureter stones often pass naturally after treatment, while stones in areas like the pancreatic duct may need to be removed using an endoscope.

What Is Extracorporeal Shock Wave Lithotripsy?

Extracorporeal shock wave lithotripsy uses shock waves generated by a lithotripter machine to fragment stones located in the urinary tract, bile ducts, or pancreatic duct. These shock waves penetrate the body and are precisely targeted using X-ray imaging. The purpose is to break stones into smaller fragments, making them easier to pass naturally or extract. Kidney and ureter stone fragments typically exit the body through urine, whereas larger fragments in the bile ducts or pancreatic duct often require endoscopic removal with a flexible tube inserted through the mouth.

Who Can Benefit from ESWL?

ESWL’s effectiveness varies based on individual factors. It may not always be the ideal option for stone removal. Success can depend on:

  • Stone composition: Some stones, such as those made of cystine or specific types of calcium, resist fragmentation.
  • Stone location: Stones in narrow ducts may remain difficult to extract even after breaking apart.
  • Stone size: Larger stones may leave behind sizable fragments that are challenging to remove.
  • Health conditions: Chronic infections or other underlying issues can reduce the effectiveness of ESWL.

Advancements in ESWL techniques, like adjusting the strength and timing of shock waves, have improved the procedure’s safety and outcomes.

ESWL for Kidney Stones

For many patients who once required major surgery, ESWL now offers a noninvasive alternative for kidney stone removal. It is particularly effective for smaller stones that can be easily visualized on an X-ray. However, ESWL may not be suitable for individuals with chronic kidney infections, as residual stone fragments could harbor bacteria. It is also less effective in cases where the ureter is obstructed by scar tissue or blockages, preventing stone fragments from passing.

Because it is a noninvasive treatment, ESWL is typically performed on an outpatient basis, allowing most patients to return home the same day. A mild anesthetic is often administered to numb the kidney area during the procedure.

ESWL for Pancreatic Duct Stones

Pancreatic duct stones, a complication experienced by nearly half of individuals with chronic pancreatitis, can block the duct, causing pain and impairing digestion. ESWL is often the first choice for treating large pancreatic duct stones due to its minimally invasive nature and higher safety profile compared to endoscopic retrograde cholangiopancreatography (ERCP). ERCP is commonly used after ESWL to retrieve fragmented stones using a flexible tube and camera inserted through the mouth. Performing ESWL first reduces the risk of pancreatic duct injury or inflammation associated with ERCP alone. Patients undergoing ESWL with ERCP are typically given general or spinal anesthesia. Depending on the outcome, patients may go home the same day or stay overnight for observation.

ESWL for Bile Duct Stones

Gallstones from the gallbladder sometimes become lodged in the bile ducts. These stones are usually removed endoscopically, but larger or hard-to-reach stones may require ESWL to break them up before extraction.

Although ESWL was once used to treat gallstones within the gallbladder, it is no longer a standard practice as it does not prevent stones from recurring. Today, minimally invasive gallbladder removal is the preferred treatment for symptomatic gallstones.

What Happens During an ESWL Procedure?

ESWL typically lasts about an hour but may take longer depending on the size and number of stones. Here’s what to expect:

  • You will lie on a specialized table equipped with the lithotripter and imaging tools.
  • After anesthesia is administered, the doctor will use X-rays and sometimes ultrasound to locate the stone.
  • The shock waves are directed at the stone, with adjustments made as necessary to ensure optimal fragmentation.
  • For bile duct or pancreatic duct stones, an endoscope may be used immediately after ESWL to remove the fragments.

Potential Risks and Limitations

While ESWL is generally safe and precisely targets stones without damaging nearby tissues, certain individuals may face higher risks or be advised against the procedure. These include:

  • Pregnant individuals
  • Those with pacemakers or other implants that might be disrupted by shock waves
  • Patients taking blood thinners or with bleeding disorders (anticoagulants must be stopped a week before ESWL)
  • Cases where stones must be urgently and completely removed, as ESWL may not always guarantee this outcome