Most kidney stones pass out spontaneously within 24 to 48 hours. However, if a kidney stone (renal calculus) does not pass out or is causing an obstruction of the urinary tract, other forms of medical intervention is considered. A range of kidney stone medication is available, not only for pain relief, but also to assist with passing out the kidney stone. If these measures fail, further treatment may include more invasive procedures. Kidney stone removal may involve a number of methods and it depends on the availability of facilities and equipment as well as the individual case.
Methods for Removal of Kidney Stone, Urinary Stones
Open surgery for kidney stone removal is rare these days. A host of other options are available which are lower risk and quicker. These techniques ‘crush’ the stone (lithotripsy) into smaller stones so that it can be passed out easily or physically removed in the operating theater. The most common of these is extracorporeal shockwave lithotripsy or ESWL for short. Other options include ureteroscopic lithotripsy or percutaneous nephrolithotomy.
Extracorporeal shockwave lithotripsy (ESWL) is the procedure of fragmenting kidney stones by shock waves generated outside the body. It is a non-invasive procedure and the preferred method of kidney stone removal for stones in the upper part of the urinary tract – renal pelvis (kidney) and proximal parts of the ureter (approximately first one-third of the ureter closest to the kidney).
This type of shock wave treatment is :
- Quick – takes 1 to 2 hours at most.
- Safe – complications and side effects are minimal if proper patient screening is done and does not require general anesthesia (GA).
- Convenient – does not require overnight hospitalization.
However, in certain situations, an ESWL is not advisable as there is a high risk of complications. This means that the procedure is contraindicated.
Under the following circumstances, the ESWL procedure should not be conducted.
- Pregnancy. The use of x-rays to isolate the location of the kidney stone and the shock waves could harm the fetus.
- Obstruction. If there is any obstruction for the passage of the stone or fragments lower down the urinary tract, ESWL should not be conducted. Constriction, stenosis or anatomical abnormality that could inhibit the passage of stones or fragments out of the urinary tract are a contraindication.
- Bleeding disorders. This includes ‘free’ bleeding or clotting disorders (coagulopathies) as well as any drugs that may affect clotting.
- Infection. This includes infection of any part of the urinary tract, including the kidney, presence of an abscess or urosepsis. Once the infection resolves with proper treatment, an ESWL may be conducted.
- Cancer of the kidney or tumors anywhere along the upper urinary tract.
Under certain conditions, an ESWL can be conducted although great care and careful monitoring after the procedure is necessary. If other options are viable, an ESWL should be avoided. These conditions include :
- Hypertension. In poorly managed cases of high blood pressure, there is the increased risk of bleeding.
- Poor kidney functioning (renal insufficiency) and urine drainage within the kidney.
- Kidney(s) that are not located in the usual anatomical position (renal ectopy).
- Malformations of the kidney.
- Kidney stones larger than 30mm (3cm). In some cases, an ESWL may not be considered if the kidney stone is larger than 25mm.
- Cardiac arrhythmias, especially if the patient is using a pacemaker, and other heart and lung related conditions.
- Certain gastrointestinal conditions (primarily those conditions affecting the small and large intestine) may be aggravated after ESWL (rare).
- Renal artery aneurysm.
- Abdominal aortic aneurysm (AAA). Rupture of the abdominal aorta is rare but there have been a few reported cases worldwide although other predisposing factors cannot be excluded in these instances.
ESWL Side Effects and Complications
Modern ESWL is safe but if proper patient screening and pre-operative testing and imaging is not done, there are risks of complications. There are some ‘side effects’ which may be noticed after the ESWL procedure but this is normal and expected. These include :
- Blood in the urine.
- Skin bruising.
- Flank pain.
- Kidney stone pain (renal colic) as the stone fragments pass out.
Other complications require immediate medical attention and can be prevented with proper screening.
- Kidney infection. In most cases there was an existing active infection that was undetected or treatment for a known urinary tract infection (UTI) was inadequate.
- Excessive and/or prolonged bleeding evident in the urine or internally around the kidney or surrounding organs.
- Stone fragments resulting in an obstruction of the urinary tract.
There are other rare complications of ESWL but these will be considered in terms of individual cases. Overall an ESWL is safer than other kidney stone destruction and removal procedures.
Urinary Stone Locations
Depending on the location of the kidney stone, the urologist will select the most appropriate method. Despite the general guidelines below, your urologist may decide upon a certain procedure based on multiple factors that is taken into consideration.
Kidney Stone in Renal Pelvis of Kidney
The best methods for removal of a kidney stone in this location is an ESWL or percutaneous nephrolithotomy. Open surgery is the last option.
Urinary Stone in Upper Ureter
This is the part of the ureter closer to the kidney. ESWL for breaking down a stone near the middle of the ureter is less successful and ureteroscopic destruction may be a better option . The best methods for this location is ESWL or ureteroscopic destruction (laser or mechanical). Laparoscopic removal may be considered if the other options are not available or feasible but it is rarely used. Open surgery is the last option.
Urinary Stone in the Lower Ureter
This is the part of the ureter closer to the bladder. The best methods for kidney stone removal at this location is ESWL or ureteroscopic destruction (laser or mechanical). Basket extraction may be necessary.
Urinary Stone in Bladder
Cystoscopic destruction is usually considered. However, stones in the bladder can become quite large and open surgery may be necessary in this instance.