Extracorporeal shock wave lithotripsy or ESWL is a medical procedure to treat kidney stones. This method uses high-energy shock waves to break the larger kidney stones into smaller crystals, for easy removal through the urine.
What is ESWL?
Extracorporeal implies outside the body. In this method, the healthcare provider uses an instrument called a lithotripter to direct high-energy sound waves specifically at the stones, causing them to break into smaller pieces. The basic advantage of this type of ESWL procedure is that it does not cause any damage or harm to the surrounding tissues and organs. This is because the energy is directly focused at the stone, via external shock waves which travel into the body from the skin and tissue.
Once, the stones are broken into smaller pieces, they eventually pass on their own through urine over several days or weeks. The procedure is only about an hour long and is non-invasive. Therefore, there is a shorter hospital stay and a very fast recovery rate.
How to prepare for ESWL?
Before the procedure, the patient must discuss with the doctor about any ongoing medications, specific health conditions and other over-the-counter medications being taken. The doctor will advise non-usage of some specific medicines to prevent any complications from ESWL.
In many cases, the doctor administers local anaesthesia to patients to numb the area and prevent pain. In most cases, the patients are given general anaesthesia, allowing them to fall asleep during the process. In the case of the latter, the patient will be advised to not eat or drink anything at least 6 hours before the scheduled procedure.
For a patient that is given general anaesthesia, they must ensure to be accompanied by friends or family while leaving the hospital. The effects of general anaesthesia can take some time to wear off and a person will not be allowed to drive in such a case.
What happens during ESWL?
ESWL is usually an hour-long procedure, allowing the person to go home the same day of the procedure. Before beginning, the patient will be asked to change into a gown and lie on an exam table for the examination. Then the patient is given sedatives and antibiotics, as needed.
After the patient is sedated, the healthcare provider sends high-energy shock waves through the skin until they reach the kidney stones. These external energy shock waves cause the large-sized kidney stones to break into smaller pieces. These pieces are then eventually flushed out of the system via urine in some days. The shock waves are directed to the exact spot of the stones with the help of the X-Ray machine.
After the procedure, the patient is observed for two hours for any complications or after-effects. In some cases, where the patient is not comfortable after the procedure or is facing any complication, the doctor might ask the patient to stay overnight for observation. However, once discharged, the patient needs to take 1-2-day rest and drink plenty of water to flush out the smaller stone fragments.
What are the risks of ESWL?
Even though ESWL is very safe, some risks can accrue. These include:
- Internal bleeding
- Blood transfusion
- Kidney damage in rare cases where the stone fragments block the urine from exiting the kidneys
- High blood pressure
- Kidney failure (very rare)
Who should not undergo an ESWL procedure?
Despite being a very effective method for kidney stone removal, and ESWL procedure is still not recommended for patients below:
- Pregnant women
- Patients that take blood thinners or have bleeding disorders.
- Patients that have a chronic kidney infection
- Patients that an obstruction or a scar tissue in their ureter
- Cases where a complete stone removal is required in one go
- Patients that have kidney stones made particularly of a specific type of calcium and cystine. These types of stones cannot be broken down easily via ESWL.
Why is ESWL required?
ESWL is required in cases where the kidney stones are too large and hence, are incapable of passing on their own. Moreover, if the patient has excessive pain, infection, or the functioning of the kidney is threatened, the doctor may recommend an ESWL procedure.
Also, in cases, where the patient has only one kidney or has had a recent kidney transplant, an ESWL procedure can help remove stone more quickly.
What are the advantages and disadvantages of ESWL?
The most prominent advantage of the ESWL procedure is that it is non-invasive and removes the kidney stones without making any incision. This consequently reduces the hospital stay and recovery time of the person.
On the other hand, while the procedure can be very successful, in some cases, there might be multiple stone fragments still left in the body and again causing symptoms. In this case, the doctor may need to reperform the procedure or in a complicated case switch to an alternative form of treatment.
Moreover, the procedure can also cause some complications, which eventually fade or are easily treatable.
In all, ESWL is a safe and effective procedure; however, it is not suitable for all kidney stone patients. The suitability of the procedure is decided by the healthcare provider.