Extracorporeal shock wave lithotripsy (ESWL) is a form of lithotripsy procedure that uses high-frequency shock waves to break down the stones in the urinary tract. In this method of treatment, an instrument known as lithotripter is used to direct high-energy sound waves to focused ultrasonic energy directly at the stones, causing them to break into smaller pieces. The basic advantage of this type of treatment of urinary stone is that it does not cause any damage or harm to the surrounding organs and tissues since the energy is aimed directly at the stone, through shock waves which travel into the body from the skin and tissue. Post the treatment, the smaller pieces of stones are eventually passed through urine over several days or weeks. ESWL procedure is approximately an hour-long procedure and has a shorter hospital stay and faster recovery time. This method or urinary stone management is non-invasive and is preferred over invasive procedure; however, certain conditions must be met to perform the medical procedure.
How does ESWL work?
ESWL is the most common form of lithotripsy used to break down large kidney stone into smaller pieces by using high-energy shock waves. Extracorporeal implies – outside the body, which is generally the source of shock waves in this treatment. In an ESWL, a special machine called a lithotripter is used to produce shock waves that travel into the body of the patient and break the large stones into smaller ones, enabling easy removal.
ESWL has been used as an effective method to remove kidney stones since the early 1980s. This is a non-invasive procedure and is relatively safer and has a quick recovery time in comparison to other invasive methods of stone treatment and management.
The procedure is approximately 45 minutes to about an hour-long, and the patient is administered with a form of anaesthesia – local, regional or general – depending on the condition. Once the procedure is completed, the debris of the stones is removed from the kidneys or the ureter via urination.
How to prepare for ESWL?
To prepare for an ESWL, the patient will need to disclose any on-going medications, drugs, supplements, treatments or medical conditions, since they could affect the overall result of the procedure. Moreover, any allergies should be priory discussed; the doctor will recommend stoppage of some drugs, medicines, etc. depending on the condition of the patient.
In some cases, where the patient needs to be administered with general anaesthesia, the doctor will ask the patient to not eat or drink anything at least six hours before the ESWL procedure. Moreover, in this condition, it is best to be accompanied by a friend or family member since the patient cannot drive back after the procedure.
What to expect in an ESWL procedure?
The procedure is performed on an outpatient basis, implying the patient will need to reach the hospital as well as leave the hospital on the same day of the treatment.
Before beginning the procedure, the patient will be asked to change into a gown and lie on the exam table on top of a soft, water-filled cushion. The patient is then administered with the required form of anaesthesia and antibiotics for sedation and fighting infection.
Once that is completed, the doctor passes high-energy shock waves through the body of the patient, directed at the kidney stones to help break them into smaller pieces, which can be easily passed through urination.
Once the procedure is ended, the patient will be kept under observation and allowed to recover for 2 hours before being discharged. In some cases, where complications arise, the patient might be asked to stay under observation for a night. After discharge, the patient is advised to take rest for 2 or more days and drink plenty of fluids essentially water for weeks following the surgery, to allow the debris to pass through.
What are the risks of ESWL?
An extracorporeal shock wave lithotripsy (ESWL) is a non-invasive method and is thus, relatively safer procedure with minimum complications. Though some rare complications that can arise include:
- Internal bleeding requiring blood transfusion
- Infection in the kidney
- Damage to nearby organs and tissues
- Damage to kidneys obstructing functioning (very rare)
- Kidney failure (very rare)
- High blood pressure
- Pain caused by the passage of stone fragments
- Blocked urine because of leftover stone fragments in the urinary tract
How effective is ESWL?
The procedure is effective depending on the type, size of the stone and the overall health condition of the patient. It works best for kidney stones that are adequately large and are located in the ureter or the kidney. That said, this procedure is not effective for cystine kidney stones, which do not break up easily and hence, will require invasive treatment methods.
On the other hand, ESWL does not replace the overall need for preventive treatment for kidney stones. It is a safe procedure and can be used for children or in cases, where the patient has only one working kidney since it causes less stress on the overall body and the kidneys.