There are several different treatment options available for kidney stones depending on a number of factors including the size, position and number of kidney stones, what the stone is made of, how long the stone has been present, whether there is ongoing pain, and whether there are any associated problems such as infection.
Some kidney stones, especially small stones in the lower ureter, may pass spontaneously without requiring surgical intervention. In some instances admission to hospital will be necessary for analgesia, and this may facilitate passage of the stone. As a general rule stones <4mm in size have up to a 90% chance of passing spontaneously, stones 4-6mm in size have ~ 50% chance of passing spontaneously, and stones > 6mm in size have < 20% chance of passing spontaneously.
It is important to strain your urine in case the stone does pass, so that it can be analysed and appropriate dietary advice given. If you have not seen the stone pass then it is important to have follow-up x-ray imaging, as the absence of pain doesn’t always mean that the stone has passed, and if left untreated it may cause damage to the kidney over time.
If there is an associated infection, ongoing pain, impaired kidney function, or the stone has failed to pass after four weeks then intervention will be required.
Uric acid stones, which are not visible on plain KUB x-rays, can be dissolved over time with medication. The treatment usually involves the use of an alkalinising agent, such as Sodibic or Citravescent, as well as the addition of Allopurinol, a medication that decreases uric acid production in the body. It is also important during the dissolution process to increase your fluid intake. Given that uric acid is a breakdown product of protein, a reduced diet of foods high in protein is also important.
Surgical treatment will be required to treat renal stones if conservative management or dissolution treatment have failed, or if it is deemed that these treatment options will not be beneficial from the outset. A more immediate decision to operate occurs if there is associated infection present, renal impairment, or ongoing pain which cannot be managed with analgesia. The surgical treatment options include: endoscopic (ureteroscopic) management, percutaneous (key-hole) surgery, lithotripsy, laparoscopic surgery or open surgery.
Stones in the ureter can often be accessed by passing a thin, long rigid instrument called a ureteroscope into the ureter under a general anaesthetic. The stone can then be managed in several different ways. Small stones can often be basketed and removed intact. Larger stones will require fragmentation using either a laser fibre or lithoclast (jackhammer). Stones in the upper ureter or kidney are often managed with a flexible ureteroscope. The flexible nature of this instrument allows access into areas of the kidney which can’t be accessed with a rigid instrument. Stones can then be fragmented using a laser fibre.
Stones unfortunately may require more than one operation. If the ureter is too tight and a ureteroscope cannot be inserted into the ureter a ureteric stent is placed. The stent is subsequently removed ~ ten to fourteen days later, at which time the ureter is a lot more accessible. Stents can irritate and cause temporary problems such as haematuria (blood in the urine), the feeling of needing to void regularly and pain in the kidney, especially with voiding (reflux pain). These are only temporary symptoms which resolve after the stent has been removed.
2.Lithotripsy or ESWL (Extracorporeal Shock Wave Lithotripsy):
This is an operation which involves focusing shock waves onto a stone under a general anaesthetic, resulting in fragmentation of the stone. The small stone fragments then pass down the ureter. Lithotripsy is a good management option for small to moderate sized stones in the kidney. The success rate depends on the size, number, position (in the kidney), and composition of the stone. This is a day case procedure which typically takes about sixty minutes. Discharge from hospital usually occurs two hours after the procedure.
Pain can sometimes be experienced with passage of the stone fragments down the ureter, but the chance of needing to have the stone fragments removed endoscopically is only ~ 5%.
3. Percutaneous (key-hole) surgery:
For larger stones within the kidney (or upper ureter), that are not amenable to lithotripsy or endoscopic treatment with laser, key-hole surgery is an option. This involves making a 1cm skin incision in the back, and creating a 1cm diameter tract through the skin into the kidney. Through this tract an endoscope can be placed and the stone can be managed with a lithoclast, laser fibre, ultrasonic fragmentation with suction aspiration, or simple basketing. The risks of this procedure are greater given that a tract is made through the vascular kidney to access the stone.
4. Open / Laparoscopic surgery:
These operations are rarely required these days due to the advent of endoscopic treatments such as flexible ureteroscopy and laser. Very large stones in the upper ureter can be managed with laparoscopic surgery, and complex staghorn calculi in the kidney can be managed with open surgery. Open surgery may be required if there are other renal/ureteric abnormalities that need correcting at the same time as the stone removal.