Kidney Shock Wave Treatment, ESWL Contraindications, Side Effects

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.

ESWL Contraindications

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.
• Obesity.
• 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, 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.