Large kidney stones may form and cause pain when traveling through or becoming trapped within your urinary tract, often becoming trapped and needing to be broken up with shock waves using lithotripsy (lithotriptic treatment). These stones are then typically broken apart using shockwave technology during an excision procedure known as lithotripsy.
Lithotripsy is an noninvasive procedure that employs shock waves to break stones down into fragments that will be passed out when you urinate, with vibration therapy enhancing this process even further. A recent study has indicated that vibration therapy could speed up this process significantly.
What is Extracorporeal Shock Wave Lithotripsy (ESWL)?
ESWL (Extracorporeal Shock Wave Lithotripter) is a procedure used to break up kidney stones with high-energy shock waves. A machine called a lithotripter attached to a cushion sits either behind your kidney or abdomen and sends shockwaves into your body; they then cause the stone to fracture into smaller pieces that pass out with urine or are extracted using an endoscope (a flexible tube inserted through your mouth). ESWL works best on smaller stones of 2 cm or less in size; larger, oblong or spicule-shaped stones can be harder for shock waves to crush apart than smaller stones of equal size or shape.
Before beginning ESWL, your healthcare provider will administer anesthesia to keep you comfortable during treatment. You’ll lie on a table or, more commonly, sit in a tub of water; from here, X-rays or ultrasound will be used to locate your stone so the lithotripter’s energy beams can target it; they may need to move you slightly during treatment in order to line up its beams with your stone.
A lithotripter works by emitting a targeted beam of shock waves into your body. As these shockwaves travel, they absorb by tissues having higher density than your stone and release energy at its stone-fluid interface, where it is then used to break apart both tissue and stone simultaneously.
After receiving an ESWL treatment, your physician will advise that you drink lots of fluids to help the stone fragments pass out of your system more quickly and take simple painkillers as needed. Depending on the type of stone involved, they may wish to conduct another urinalysis after one month or more and prescribe specific medication that could lower future kidney stone risks.
Some individuals may have large stones that cannot be extracted via ESWL, in which case your doctor may suggest ureteroscopy — a procedure where they access stones by going through your bladder — instead. In extreme cases, people with very large kidney or bile duct stones may require open surgery that requires making larger incisions in the abdomen to access these stones.
How is ESWL done?
Lithotripsy uses an external machine that generates shock waves to pulverize kidney stones into small fragments. It is an effective and minimally invasive treatment option without needing surgical incisions or additional equipment. Most insurance plans cover this procedure, though coinsurance and deductibles may apply; our office can provide confirmation and cost estimates as necessary.
As part of your procedure, you will lay on a treatment table while the device (known as a lithotripter) will be positioned over your stone(s). A cushion filled with water will protect you from shock waves generated by this device. A local anesthetic may be applied by the provider to help reduce discomfort; once numbness has set in, activation will occur within approximately an hour and could take multiple sessions depending on your specific condition and size of stones involved.
Before undertaking ESWL, it is recommended that a non-contrast CT scan is performed to precisely assess the size and location of your stone(s) within your kidneys and ureters. This allows your physician to plan an ESWL session appropriately as any changes arise during treatment sessions; additionally, an X-ray may also be taken post treatment to verify that all pieces of your stones have been successfully broken up.
Your physician will begin your ESWL treatment at a low energy level and gradually increase it until a higher intensity level is recommended for optimal results. This approach should prevent stones from moving outside the direct path of shockwaves, and help avoid unwanted side effects like renal hematomas or ureteral obstruction.
Based on your condition, depending on ESWL you may receive medications such as Tamsulosin or Ketorolac to relax the bladder and make passing stones easier. Post-ESWL expect pain as fragments work their way through your system for days or even weeks after.
ESWL should not be performed on pregnant women or those who have uncontrolled bleeding disorders or who take blood-thinners like warfarin (Coumadin). Furthermore, this procedure may not be safe for individuals who possess cardiac pacemakers.
What are the risks of ESWL?
ESWL is a noninvasive treatment for kidney stones that uses sound waves to break them up into smaller pieces that can be passed out of the body via urine. This noninvasive technique has become increasingly popular as an alternative to more invasive procedures that may require hospitalization and long-term recovery times, while also decreasing risk of infection due to less likely holding onto infectious bacteria in stone fragments.
Your doctor will use a machine called a lithotripter to deliver shockwaves through your skin directly towards any kidney stones that are present, penetrating them into your kidney and creating pressure that cracks or fragments them. The procedure usually lasts about an hour in either a clinic or hospital setting and afterwards you should drink plenty of water in order to flush away broken stone particles out of your system after treatment.
Before your procedure, you will be required to fast for several hours and provide your medical history and sign a consent form. Your physician will review these records as well as conduct a physical exam in order to assess the size, location, and structure of the kidney stone in question. In some instances blood thinners should also be discontinued prior to your ESWL session.
Once your ESWL procedure begins, you will lie on a padded table or sit in a tub of water and your provider will use X-rays and ultrasound imaging technology to locate kidney stones in real time so shockwaves can be delivered effectively with limited collateral damage to surrounding tissue. An anesthesia may also be provided during the procedure for your comfort and stillness during this procedure.
Once on the lithotripsy table or tub of water, you will be asked to remain as still as possible during treatment, which could last up to half an hour. A monitor will display the ESWL process while your provider will check your progress regularly to make sure that you remain comfortable during ESWL treatment. If you have an implanted cardiac pacemaker, your physician may need to make special accommodations for its placement during lithotripsy.
What are the benefits of ESWL?
ESWL offers a safe and effective treatment option for small kidney stones. The procedure does not involve surgery or any form of sedation; rather, its goal is to break up and dissolve kidney stones through urine output.
Beginning the procedure begins with a medical assessment to ensure the patient is an appropriate candidate for ESWL. A full review of their history and physical exam are performed, along with imaging scans (X-ray or ultrasound) used to locate kidney stones. Once located, the patient is either placed supine or prone on a table depending on where their stone lies in their body – with either sedation or twilight anesthesia administered prior to beginning so they don’t experience any discomfort during their procedure.
A generator is then utilized to produce pressure waves targeted directly at the kidney stone site. Once they reach their intended destination, pressure wave energy converts to kinetic energy that breaks up and disintegrates the stone fragments into smaller fragments. After receiving shockwave treatment, patients are observed for some time afterward to ensure there are no immediate complications or side-effects.
After an ESWL procedure is performed, xrays will be taken to assess the degree of stone fragmentation. If fragments remain within the urinary tract after repeated attempts with ESWL or more aggressive approaches such as ureteroscopy or percutaneous nephrolithotomy may be necessary for further treatment.
Fragments of kidney stones may become lodged in the ureter, leading to severe pain and creating an emergency medical situation. You can avoid this complication by following your physician’s recommendations for dietary modifications and 24-hour urine testing with directed therapy.
ESWL can be effective in treating kidney and ureter stones, though more dense ones may prove challenging. Multiple ESWL treatments or more invasive approaches such as laser lithotripsy, ureteroscopy or surgical removal may be required in such cases.