Extracorporeal Shock Wave Lithotripsy (ESWL) is a non-invasive technique for the treatment of urinary lithiasis, which is popularly known as kidney stones. The urologist explains that they are stones lodged in the kidney or in the urinary tract (ureter). We ask ourselves a series of questions whose answers may be interesting to know.
Why do we say that it is not an invasive technique?
It is a technique that uses waves generated outside our body and that are transmitted by water (it must be remembered that our body is water in more than 70 percent) until reaching the lithiasis, where they will impact to break it. They are acoustic waves (they are heard) with the property of fragmenting when colliding with the stone (shock waves).
Once the treatment has been applied (the SWL session), it will only be necessary to wait for the small fragments in which the lithiasis breaks down are expelled to the outside, little by little, through the urine.
It is not necessary any type of intervention, surgery, instrumentation … just lie down on the stretcher and let the treatment be applied. The urologist will study each case and plan a specific strategy according to the circumstances of each patient and each stone situation.
Can SWL be applied to all patients?
ESWL can be applied in almost all patients and types of stones, both renal and ureteral. Even in some ESWL units, such as the one at the Fundación Jiménez Díaz University Hospital in Madrid, they can be treated in the phase of renal colic (renal colic), which will make the pain disappear or last less, the stone will break into pieces, it is better eliminated, and the patient can regain his life before renal colic much sooner.
Only some stones that cannot be seen on an X-ray, due to their chemical composition, location or size, interference from some bone structures, organs or even intestinal gas, or in some situations such as pregnancy or diseases with blood clotting disorders. blood, SWL could be more complex to perform or be contraindicated. Your urologist will surely know if you are a candidate or not but remember that almost all patients and stones are.
Does the ESWL require any prior preparation to be applied?
ESWL does not require any special preparation, not even fasting, although it is recommended not to have eaten too much in the previous hours.
Is it a painful procedure?
Some patients describe the sensation of a “slight electrical current” when shock waves pass through the skin to reach the stone. Others report some discomfort. But no patient should suffer pain during treatment. If it does appear, an intravenous analgesic regimen is deepened, and the situation is overcome. In this way, the patient is comfortably lying down while the shock waves act.
In other words, treatment is always given so that the patient does not feel pain, to the point that some patients fall asleep during the procedure. Also, if the patient wants, they can bring music and listen to it during this time. This will help to distract you and make it less time consuming, although it usually does not last more than an hour or hour and a half.
Do I have to stay in the hospital?
ESWL is an outpatient treatment: the patient arrives at the hospital; the procedure is applied and goes home. It is advisable to go accompanied. Due to analgesic medication and having to maintain the same position all the time, sometimes the patient can end the treatment upset, dizzy or disoriented temporarily and temporarily. This feeling passes soon, but it is better not to go home alone, much less drive next.
How will I know if ESWL has been effective?
As we have mentioned, SWL consists of the application of waves that, from outside the body (hence the name extracorporeal), break the stone. Once broken into small fragments, these must be expelled alone to the outside by themselves thanks to the flow of urine through the urinary system.
It is normal for the days following SWL treatment to observe the elimination of grit in the urine, or even some fragment of the lithiasis. If it does, please save it for viewing and analysis.
After a few days, about three weeks, your urologist will repeat the tests he considers seeing the effectiveness of the treatment, usually an X-ray. Although many times the treatment is effective in the first days, it is necessary to wait 3-4 weeks for the continuous flow of urine to finish helping the elimination of the fragments by an entrainment mechanism.
Do you have complications?
Like any treatment, it can have complications, but these are minimal and generally not very relevant and easily controlled. It may be common to have some discomfort during the expulsion of the grit, or some hematuria (blood in the urine). Other complications, such as infections or kidney damage, are very rare (less than 0.5 percent), and infinitely much less and important than those that can be suffered with another procedure of greater invasiveness or surgical aggression.
Can SWL be repeated if it has not been effective?
If the stone has not fragmented, or has not been completely fragmented, the treatment can be repeated as many times as necessary. And it can be repeated over time, if new stones may appear in the future.
Being a minimally invasive treatment, which is practiced on an outpatient basis, with hardly any major complications associated with it, and with little disruption to the life of the patient while undergoing it, makes ESWL very attractive for the resolution of urinary stones.