A nephrolithotomy is a surgical procedure that removes kidney stones. The most common method is the percutaneous nephrolithotomy, in which a small incision is made in the back and instruments inserted through a tube into the kidney to remove the stones. Open surgeries, which involve a larger incision to access the kidney directly, are not performed very often, but may be required when the stone is particularly large or cannot be removed in any other way. Surgery is usually only recommended when a patient is not able to pass a kidney stone naturally through the urine, and when other techniques to break up the stone (like lithotripsy) are not successful.
What Are Kidney Stones?
Kidney stones are formed when urine is super-saturated with certain minerals, including calcium and uric acid. They can occur in patients who have low urinary output, excrete a lot of salt or have acidic urine. Kidney stones range in size from microscopic crystals to the size of a golf ball, and they may sometimes pass out of the body in a urine stream. If they are large, their passage from the kidney, through the urethra, and out of the body can be very painful.
When Is Surgery Appropriate?
A surgeon will usually perform a nephrolithotomy only when the stone or stones are very large — bigger than 1 inch (2 cm) in diameter — or irregularly shaped. Healthcare professionals usually try other, more conservative methods, such as waiting for the stone to pass naturally or using medications that help the urinary system to relax so that the stone can move through, before recommending a more invasive treatment. Stones that cause extreme pain, infection, or which block the flow of urine may need to be removed, however. The surgery has a 95% success rate.
The Surgical Procedure
Patients undergoing a percutaneous nephrolithotomy receive general, regional, or spinal anesthesia before the procedure begins. First, the kidney stone's location must be determined, and then a small incision is made in the patient's lower back. A needle is passed through the incision into the kidney and a guide wire is passed through the needle. A tube is then passed over the guide wire, and the stone is removed through the tube. If the surgeon crushes the stone with shockwaves or a laser before removal, the procedure is known as a nephrolithotripsy.
An open nephrolithotomy is typically performed under general anesthesia. A larger cut is made in the patient's back or side so that the affected kidney can be seen. The organ is then cut open so that any stones can be removed. Because this type of surgery requires larger incisions, there is more risk of bleeding or infection than with a percutaneous nephrolithotomy, and it may take the patient longer to recover. An open procedure is rare, and usually only performed when the stone is extremely large or if there is difficulty in accessing it in the kidney using the percutaneous method.
A patient who undergoes either surgery can often expect to remain in the hospital for two or three days after the procedure. He or she will most likely have both a urinary catheter and a nephrostomy tube leading directly from the kidney to drain urine for several days after the surgery. Patients will be encouraged to drink large quantities of water during the healing process; it is normal to have some blood present in the urine. Most people can return to work after a few weeks.
Patients should expect some pain and fatigue after the surgery, but should begin standing and walking as soon as the medical staff say that it is safe to do so. This can help prevent the development of blood clots. Breathing exercises may also be recommended to help prevent lung infections. A patient may only be able to eat ice chips and a small amount of water on the first day after surgery, but usually start to return to a normal diet within a day or two.
The risks of a nephrolithotomy include bleeding, which may occur if the blood vessels in the organ are damaged during the surgery. The kidney may be nicked by a scalpel, but this complication is not serious and usually corrects itself. A rare, but more serious, complication is injury to organs near the kidneys; in some cases, there has been damage to the spleen, liver, or gallbladder. Any surgery has the risk of a infection.
In some cases, a percutaneous nephrolithotomy may be converted to an open one if the surgeon encounters problems during the procedure. Open surgery has a greater risk of infection and a longer recovery time.
Before surgery is performed, a healthcare professional may recommend extracorporeal shockwave lithotripsy (ESWL). This treatment uses strong sound waves to break up the stones, allowing them to pass through the urine or making them easier to remove with surgery. Although less invasive, ESWL can be painful and leave bruises on the back or stomach.
Ureteroscopy may also be an option to treat kidney stones. In this procedure, a tube is inserted into the kidney through the ureter, allowing urine to pass out of the body and instruments to be threaded through it to the organ. When used with ESWL, electrohydrauIic, or laser lithotripsy, the stone can first be broken into pieces and then removed through the tube.