The kidneys are designed to filter our blood, ridding it of bad or poisonous materials yet helping us retain valuable sugars, salts and minerals. Urine is the waste product of the filtration process, which is produced in the kidneys and continuously trickles through two 10 to 12-inch long tubes called ureters, that stretch from the kidney to the bladder. The ureters are about one-fourth of an inch in diameter and their muscular walls contract to make waves of movement that forces urine into the bladder. The bladder is an expandable structure, and stores the urine until it can be conveniently disposed. The tube through which the urine flows out of the body is called the urethra.
Central Texas is conveniently located in the “Stone Belt” of the USA? So called for our abundance of kidney stones.
- In the U.S., more than a million kidney stone cases are diagnosed each year, with an estimated 10 percent of Americans developing kidney stones at some point in their lives. Overall, the number of cases is rising.
- Theories about the Stone Belt and more kidney stones in regions like ours point to a combination of higher, area temperatures, followed by increased sweat and dehydration, and more minerals in our water supply.
Kidney stones are some of the most painful and prevalent urologic disorders affecting women (and men). Fortunately, many women who are diagnosed with a kidney stone will be able to pass their stone without any intervention or surgical procedures.
However, if you are not so lucky as to pass your stone spontaneously, Dr. Shaw has extensive experience in quickly evaluating and treating kidney stones in the fastest, most minimally invasive method possible. Getting you back on your feet is our number one priority.
Once your kidney stone is treated, Dr. Shaw’s top priority is for you to never have a stone again! Dr. Shaw prides himself on performing a thorough exam which includes a simple urine study, as well as analyzing the stone itself with photospectrometry (yes, that’s a long word) to find out why you made the stone, and stop or reduce the chances of one forming again. Although some patients’ cases are more challenging than others, he has patients who used to form several stones a year, who no longer do!
Kidney and Ureteral Stone Information
How does the urinary tract normally work?
What is a kidney stone?
A stone begins as a tiny grain of undissolved material located where urine collects in the kidney. When the urine flows out of the kidney, this grain of undissolved material is left behind.
The material deposited is usually a mineral called calcium oxalate; there are other, less common, materials that may also form a kidney stone such as cystine, calcium phosphate, uric acid and struvite. Over time, more and more undissolved material is deposited, and the stone progressively becomes larger and harder to pass through the body on its own. Stones as small as 2 mm have caused many symptoms while those as large as a pea have quietly passed.
What is the difference between a kidney stone and a ureteral stone?
Fortunately, most stones enter the ureter when they are still small enough to pass down the entire ureter into the bladder, allowing it pass out of the body with urination.
With ureteral stones, by the time they leave the kidney, they have grown too large to pass through the entire ureter and may become lodged in a narrow part of the ureter, causing pain and possibly blocking the flow of urine. These stones may need to be treated by a urologist.
Who forms kidney stones?
What are some risk factors for kidney stones?
If you know that you form stones, follow these guidelines:
Hydrate – Aim to maintain 2 liters of urine output each day by drinking fluids.
A high-protein diet can cause the acid content in the body to increase. This decreases the amount of urinary citrate, a “good” chemical that helps prevent stones. As a result, stones are more likely to form.
A high-salt diet is another risk factor, as an increased amount of sodium passing into the urine can also pull calcium along with it. The net result is an increased calcium level in the urine, which increases the probability for stones. Intake of oxalate-rich foods such as leafy green vegetables, nuts, tea or chocolate may also worsen the situation.
Medical conditions – Certain conditions of the bowel can also increase the risk such as chronic diarrhea, Crohn’s disease, and gastric bypass surgery.
Genetics – Family history of stones, especially in a first-degree relative (parent or sibling), dramatically increases the probability of having stones.
Obesity – While kidney stones may be formed with certain diseases and medications, much of that rise in incidence can be attributed to poor eating habits and the growing rate of obesity. Because kidney stones are caused by what we eat and our level of activity, they are prevented through the same mechanisms as well.
What are the symptoms of a kidney stone?
The pain often begins suddenly as the stone moves in the urinary tract, causing irritation and blockage. Usually, a person feels a sharp, cramp-like pain in the back and in the side of the area of the kidney or in the lower abdomen, which may spread to the groin. Also, sometimes women will complain of blood in the urine, difficulty voiding, nausea and/or vomiting.
Occasionally stones produce no symptoms at all. But while they may be “silent,” they can be growing, even threatening irreversible damage to kidney function. More commonly, however, if a stone is not large enough to prompt major symptoms, it still can trigger a dull ache that is commonly confused with intestinal or muscle pain.
If the stone is too large to pass easily naturally, the pain continues as the muscles in the wall of the tiny ureter try to squeeze the stone along into the bladder. Women may feel the need to urinate more often or feel a burning sensation during urination. If the stone is close to the lower end of the ureter at the opening into the bladder, a person will frequently feel like they have not fully completed urination.
If fever or chills accompany any of these symptoms, then there may be an infection. Contact your urologist immediately.
What are the signs of a problem?
If the pain is persistent, continues to worsen or you have fever/chills these are signs that the kidney stone needs to be managed quickly. These can also be signs of a kidney infection which can become serious in the setting of a kidney stone if left untreated.
You should notify your urologist if any of the above symptoms occur.
How are ureteral stones diagnosed?
If your doctor suspects a stone but is unable to make a diagnosis from a simple X-ray, they may scan the urinary system with computed tomography (CT).
What are some treatment options?
- causes constant and intractable pain
- causes persistent nausea and vomiting, such that the woman is not able to tolerate food or liquid
is too large to pass on its own
- blocks the flow of urine
- causes an ongoing urinary tract infection
- harms the function of the kidney
- does not pass after a reasonable period of time.
Historically, the surgical removal of a kidney stone involved an operation with an incision (open surgery) and an often lengthy recovery time. Today, though, most stones can be treated in a minimally invasive, or even non-invasive way. As a result, recovery times are now just days, not weeks. Some of the treatments for kidney stones include:
Extracorporeal shockwave lithotripsy (ESWL®): ESWL Is the most frequently used, non-invasive procedure for eliminating kidney stones. Shock wave treatment uses a machine called a lithotripter, which works by directing ultrasonic or shock waves, created outside your body (“extracorporeal”) through skin and tissue, until they hit the dense kidney stones. The impact of the shock wave causes stress on the stone; the cumulative effect of repeated shock waves is one of increasing stress on the stone, until eventually the stone crumbles into small pieces. These small pieces, about the size of grains of sand, usually pass easily through the urinary tract, and are voided out in the patient’s urine. Shock-wave lithotripsy is generally used when the stone is not excessively large, the kidney is functioning well, and there is no blockage to the passage of stone fragments.
In the original ESWL devices, the patient used to recline in a water bath while the shockwaves were transmitted. Today, the machines are more compact and have a soft cushion on which the patient lies. Fluoroscopy is used to locate the stone and focus the shockwaves.
In most cases, shockwave lithotripsy is done on an outpatient basis, and a session takes about 30-45 minutes. Recovery time is short and most people can resume normal activities in a few days. Because of possible discomfort during the procedure, it is completed under general anesthesia. Once the treatment is completed, the small stone particles then pass down the ureter and are eventually urinated away. In certain cases, a stent may need to be placed up the ureter prior to SWL to assist in locating the stone or prevent the kidney from being obstructed by passage of stone fragments. For certain larger stones, one ESWL session by itself may not free the patient of all stone material. A repeat ESWL session may be necessary.
ESWL is not the ideal treatment choice for all patients. Women who are pregnant, obese, have obstruction past the stone, have abdominal aortic aneurysms, urinary tract infections or uncorrected bleeding disorders should not have ESWL. In addition, certain factors such as stone size, location and composition may necessitate other alternatives for stone removal.
Certain types of stones, including cystine, calcium oxalate monohydrate may be resistant to SWL and may necessitate an alternative treatment approach. In addition, larger stones may not break up into pieces small enough to be discharged from the kidney. Stones located in the lower portion of the kidney also have a decreased chance of passing.
While shockwave lithotripsy is considered safe and effective, it can still cause complications. Most patients experience blood in their urine for a few days after treatment. Bruising and minor discomfort in the back or abdomen from the shockwaves are also common. To reduce the risk of complications, urologists often tell their patients to avoid aspirin and other drugs that affect blood clotting for a period of time before treatment. Another complication may occur if the stone fragments cause discomfort as they pass through the urinary tract. In some cases, the urologist will insert a small tube called a stent through the bladder prevent this complication.
Ureteroscopy (URS): This treatment involves the use of a very small, fiber-optic camera called a ureteroscope, which allows access to stones in the ureter or kidney. The ureteroscope allows the urologist to directly visualize the stone by progressing up the ureter via the bladder. No incisions are necessary. It is an outpatient procedure, under general anesthesia, and usually takes about 45 minutes.
A tiny camera is used to help guide the procedure is inserted through the urethra, then advanced through the bladder and up the ureter. Once the stone is seen through the ureteroscope, we will use either a laser to break up the stone, or a small, basket-like device can be used to grasp smaller stones and remove them. Once the stone has been completely treated, the procedure is done. Often, the urologist may choose to place a stent within the ureter, to allow any post-operative swelling or reaction to subside. The stent typically remains for three-to-five days and is removed in our clinic.
In URS, there is a small possibility that the ureteral wall could be damaged or torn during the procedure. If this occurs, placement of a stent for two to three weeks is usually sufficient to allow the damaged area to heal. Very rarely, there is a complete tear of the ureter, which requires open surgery to repair.
Percutaneous nephrolithotomy (PNL): This procedure involves going directly into the kidney (by making an incision in the skin) to remove a stone. It is not typically used unless stones are larger, are in a location that does not allow effective use of SWL, or cause a blockage so severe that they cannot be bypassed using stent. Rarely is open surgery, the most invasive treatment performed these days.
My stone has not passed, do I need surgery?
If ureteral stones do not pass in six to eight weeks, a surgical intervention is generally required to avoid potential damage to the kidneys and continued symptoms.
What can be expected after treatment?
How can I prevent ureteral stones?
- Increasing fluids – drinking 6 or more glasses of water per day; this helps dilute the urine and reduces the formation of stones. At least 50% of total fluid intake should be water. In warmer climates like ours or for physically active people, an even higher fluid intake is recommended. Drink enough water to make the urine a pale yellow color.
- Moderating Calcium Intake – Unless told otherwise by your physician, it is not necessary to deprive yourself of calcium or do it in excess, but certainly moderate your intake. Usually the body does not absorb more calcium than is needed. If you need to take calcium supplements for osteoporosis or other reasons, please make sure it is calcium citrate (i.e. Caltrate), not calcium carbonate.
- Increasing citric acid – this is found in citrus foods, and most potently in lemons; adding a capful of lemon juice to your water every day will help stones from forming and sticking to one another. This prevents larger stone formation.
- Decreasing caffeinated beverages intake – Cut back to one to two servings of caffeine a day. This includes coffee, soda, tea, iced tea, and any energy drinks. These all tend to be highly linked to stone formation.
- Decreasing Oxalate – The majority of stones are made of calcium oxalate, which bind together in the intestines. This reduces calcium’s ability to be absorbed, and an excess of oxalate will be excreted into the kidneys. Foods that contain large amounts of oxalate should be reduced or eliminated: rhubarb, spinach, strawberries, chocolate, wheat bran, nuts, beets, and tea.
Other foods to reduce/take in moderation include: green beans, grits, okra, blackberries, raspberries, celery, dark leafy greens, soy products, squash, sweet potatoes, wheat germ, draft beer, parsley, and eggplant.
- Decreasing sodium, sugar, and animal protein – Sodium and sugar can easily be reduced by avoiding packaged and processed foods. Keep salt intake between 2300-3500 mg a day. People who tend to develop kidney stones should avoid eating more protein than the body needs each day and decrease consuming red meats and fish in particular.
Increasing fiber – Insoluble fiber that is found in wheat, rye, barley, and rice may help to reduce calcium in the urine.
Will my children get stones because I have them?
In addition, more than 70 percent of people with certain rare hereditary disorders are prone to the problem. Those conditions include cystinuria, which includes an excess of the amino acid, cystine that does not dissolve in urine and instead forms stones of cystine and primary hyperoxaluria, an excess production of the compound oxalate, which also does not dissolve in urine, forming stones of oxalate and calcium.
Are gallstones and ureteral stones related?
Post-operative Instructions for ESWL:
- Although this is an outpatient procedure, please you will need to have a ride home due to the effects from the general anesthesia.
- Make sure that you are drinking plenty of water (at least 6-8 glasses a day) to help wash out the fragments.
- Mild bruising on the side where the procedure was performed which will resolve within a few days.
- Pain on the side the stone was removed is common and can range from a dull ache to cramping. You will be prescribed pain medication to take after the procedure. Take it as needed.
- Urinary frequency, mild burning with urination, and blood in the urine is common and should resolve over one to two days.
- The stone fragments will pass on their own, and usually do not require a stent with this procedure. You may have some mild discomfort with the passing of fragments, and will notice that your urine is cloudy.
- Slowly increase your activity levels. We certainly recommend taking the rest of the day off after your procedure.
Ureteroscopy with Basket/Laser and Stent Post-Operative Instructions:
- Although this is an outpatient procedure, please make sure you have a ride home due to the effects from the general anesthesia.
- Pain on the side the stone was removed is common, and can range from a dull ache to cramping. You will be prescribed pain medication to take after the procedure as needed.
- One to two days after surgery you may experience burning or frequency with urination, back pain or discomfort, blood in the urine, bladder spasms, and passage of stone fragments.
- Make sure that you are drinking plenty of water (6-8 glasses a day) to help wash out the fragments.
- If a stent was placed after your procedure, it is removed in a quick in-office procedure. The length of time for stent placement depends on a number of factors including the size of stone, any abnormalities within the urinary tract, and severity of stone disease.
- A stent is placed to help keep the ureters open, and prevent them from swelling shut. This also allows stone fragments to pass through easily. You may walk, jog, do yoga, and lightly exercise with your stent in place. Just be cautious and monitor your pain level when doing so.
- Regarding physical activity, it is a good idea to take the rest of the day off (the day of the surgery), and recover. Slowly increase activity levels as the week progresses. If you have a physically demanding job, we will recommend light duty for about a week after your surgery.