A non-invasive way to remove kidney stones. Extracorporeal shock wave lithotripsy (ESWL) passes high-energy shock waves through the body. These waves break stones into pieces as small as grains of sand which are small enough to leave the body through the urine.
During the procedure, you will lie down on the bed of the lithotriptor. An X-ray or ultrasound is used to locate the stone. Once placed, the stone is the focus of an externally applied high-intensity acoustic pulse. The treatment is said to feel like an elastic band snapping against the skin.
What does the treatment involve?
The patient lies on a soft cushion or membrane through which the waves pass. During the approximately 30-minute procedure, 3,000 shock waves are delivered to the stone to crush it.
What are the advantages and disadvantages of this treatment?
The main advantage of this treatment is that it doesn’t require surgery. The disadvantage is that the you still have to pass the small fragments of the original stone. It is common to pass blood in the urine after the procedure and to have pain in the kidney and ureter as the small stone fragments pass.
Can this treat all types of kidney stones?
Unfortunately, no. Uric acid and cysteine kidney stones are not visible on plain X-ray and therefore can’t be targeted by lithotripsy. In addition, stone fragments are occasionally left in the body and additional treatments are needed.
Will I need anesthesia?
In general, some type of anesthesia—either sedation, regional or general—helps you remain still and reduces discomfort.
Are there any restrictions after treatment?
After treatment is complete, you can move about almost at once. Many people can fully resume daily activities within one to two days. Special diets are not required, but drinking plenty of water helps the stone fragments pass. Some pain may accompany this process and could last four to eight weeks. Oral pain medication may also be necessary to relieve symptoms.
Usually you will be asked to strain your urine afterward to collect pieces of the stone for analysis.
Are there complications or side effects?
Most patients have some blood in the urine for a few days. The shattered stone fragments may cause discomfort as they pass through the urinary tract. Sometimes, the stone is not completely shattered, and additional treatments may be needed. Patients may develop a urinary tract infection or bleeding around the kidney.
ESWL is not recommended if you
- Are pregnant. The sound waves and X-rays may be harmful to the fetus.
- Have a bleeding disorder.
- Have a kidney infection, urinary tract infection, or kidney cancer.
- Have kidneys with abnormal structure or function.
Can all kidney stone patients have this kind of treatment?
No. Your candidacy for treatment is based on the size, number, location and composition of the stones. Also the stones must be clearly viewed by the X-ray monitor so the shock waves can be targeted accurately. If anatomical abnormalities prevent this, other methods of stone removal may have to be considered.
Through examination, X-ray and other tests, the doctor can decide whether this is the best treatment for you. In some cases, extracorporeal shock wave lithotripsy may be combined with other forms of treatment.
How successful is the treatment?
In those patients who are thought to be good candidates for this treatment, about 70 to 90 percent are found to be free of stones within three months of treatment. The highest success rates seem to be in those patients with mobile stones that are located in the upper portions of the urinary tract (kidney and upper ureter). After treatment, some patients may still have stone fragments that are too large to be passed. These can be treated again if symptoms persist.
Ureteroscopy is a minimally invasive means of assessing the ureter, the tube that transports urine from the kidney down to the bladder. It is commonly performed for evaluation of kidney stones or blood in the urine of unknown origin, and for treating urinary tract cancers and narrowings of the ureter.
Before ureteroscopy, this kind of examination had to be done with open surgery. Today, however, a urologist can look in the ureter with a small scope about the size of a cocktail straw.
Each ureteroscope has a light and a camera, as well as a port through which a urologist can place a laser fiber, a stone basket, biopsy forceps or water irrigation.
A ureterscopy takes place in a operating room, where the patient receives either spinal or general anesthesia. After intravenous antibiotics are administered, the ureteroscope is inserted through the urethra into the bladder and then through the ureteral orifice and up into the ureter. Once in the ureter, the urologist can break up and remove a kidney stone, take a biopsy, vaporize a cancerous growth, or dilate the narrow ureter.
The operation can take from 30 minutes to two or more hours, depending on location and size of the stone. Most procedures last an hour.
After the procedure, the urologist sometimes leaves a stent, a small rubber tube that lies in the ureter between the kidney and the bladder. This allows the flow of urine between the kidney and the bladder, facilitating the passage of stone fragments into the bladder. The stent is removed at a later date, usually less than a week, is contained entirely within the body, and should not interfere with urination.
Possible Complications Include
- Failure to remove the stone or cancer
- Perforation of the ureter
- Injury to other structures including the urethra, bladder, ureter or kidney. In very rare cases, injury may require immediate repair in the operating room with open surgery.
- Infections of the urine, blood or kidney may occur.
- A scar or stricture may occur weeks or months following a significant perforation, with repair required in a small percentage of cases.
- Bloody urine that lasts one to two days post-procedure
- Discomfort or nerve damage, though rare, can occur from positioning during surgery.
Percutaneous nephrolithotomy (PCNL)
This minimally invasive surgery is ideal for larger stones in the kidney or upper ureter, or for stones that are not good candidates for lithotripsy.
While lithotripsy and ureteroscopy can be performed without an incision, PCNL cannot. However, this smallest of intrusions is still considered minimally invasive. You will be hospitalized anywhere from one to five days, depending on complexity.
During the procedure, a surgeon places a telescope directly into the kidney through a small tract placed below the tip of the lowest rib. This tract is about the size of a pencil. The operation requires a general anesthetic and the patient is positioned facedown or prone on a well-padded operating table. A telescope is placed into the bladder and a small catheter tube is passed up the ureter of the involved side.
Before the telescope is placed in the kidney, a small catheter is passed up the ureter of the stone’s side to inject contrast fluid into the kidney and help visualize the stone with fluoroscopic or X-ray imaging. A second catheter is placed in the bladder to drain urine.
Very large kidney stones and staghorn stones (large stones filling the internal branches of the kidney) are pulverized with a variety of instruments including ultrasound, pneumatic hammers, and lasers. Small fragments may be vacuumed out and larger fragments the size of peanuts (10mm) may be removed intact.
A surgeon may insert flexible telescopes to inspect the internal branches of the kidney and meticulously remove stones. For some stones with a complex shape, more than one tract may be necessary to eliminate all stone material.
The goal of the surgery is the complete removal of all stones, especially for stones related to infections, as bacteria inhabit the interior of the stone and cause stone crystals to form and grow. In order to avoid recurrent infection in these cases, all stone debris, including the bacteria, must be eradicated.
Upon completion of the operation, the surgeon places a temporary tube into the kidney through the established tract and sutures it to the skin for security. The ureteral catheter is removed and the bladder catheter is left in place. You will be awakened from the anesthesia and transported to the recovery room where monitoring takes place for about an hour. Then you will be transferred to an inpatient floor.
This operation usually requires pain medication for comfort and a special intravenous (IV) pump for delivering pain medicine if needed. You will be on bed rest for the rest of the day and overnight. You may take clear liquids, but we usually discourage regular foods until the following day.
Special pneumatic compression pumps are placed on your legs while at bed rest to avoid a possible blood clot. Urine drainage from the catheters is typically rose or cranberry in color.
The following morning the you may have X-rays to determine if any stone material remains. If there are no problems, the bladder catheter is removed. If there are no stones, no leakage within the kidney noted, and no blockage in the ureter by stone fragments or blood clots, the tube in the kidney is removed either the same day or the following day. You’ll then be ready to go home.
If there is residual stone material, the urologist usually waits at least another day and performs a second look into the kidney to remove the remaining stones. Usually there is some stone material not visible at the original operation. This second-look operation may be performed with general anesthesia if it appears that substantial manipulation will be necessary, or with IV sedation alone if there is minimal residual stone remaining.
This procedure is usually brief, less than one hour. Afterward, you are sent to the recovery room for monitoring and then back to the inpatient floor.
The nephrostomy tube may be kept in place for one or more days until the urologist decides it is safe to remove it. You could be discharged with the tube temporarily in place, draining urine into a leg bag. In a few days, you will go to your doctor’s office for its removal, an essentially painless procedure that takes only a few seconds.
In two weeks, you will get a follow-up battery of tests: abdominal radiograph (KUB), renal ultrasound and blood tests.
Laboratory analysis of extracted stones is available about three or four weeks after surgery. For large stones, residual stone may persist after one or more percutaneous procedures. We may recommend lithotripsy to better clear all remaining fragments. Occasionally, irrigation of residual debris through one or more nephrostomy tubes is recommended to flush out and dissolve the remnants, depending on the composition of the stone.
In six weeks, we may order an intravenous pyelogram (IVP) to evaluate your kidney function. More follow-ups should be scheduled for six and twelve months to gauge recurrence, and every year after that. If you had infectious stones, you should follow up every three months for the first year.
There is a 95 percent success rate of eradicating large simple stones. The staghorn stones may require more than one procedure, but the stone-free success rate is 90 percent.
Risks of PCNL
- Bleeding requiring a blood transfusion is necessary in about 2 percent of cases. The risk of transfusion is increased for a larger, more complex stone, or if multiple tracts are required.
- Infection requiring IV antibiotic treatment is greater—about 5 percent with a possibility for severe life threatening infection of less than 1 percent.
- Injury to other organs, such as the bowel, spleen or liver, is possible but rare.
- Internal leakage of urine is an uncommon occurrence that may prolong hospitalization until adequate drainage is performed.
- Injury to the space around the lung (pleura) is rare but possible if a tract over a rib is necessary for a stone in the upper kidney. A collapsed lung or fluid collection around the lung may occur, requiring a tube for a few days to repair this problem.