Kidney Stone Center of Maine

Kidney Stones

About Kidney Stones

Kidney stones are hard, solid particles that form from minerals within the urinary tract. Stones range from the size of a grain of sand to the size of a golfball or larger.

Kidney stones can be a very painful experience which has to be tolerated periodically. In fact, kidney stone disease is a complex problem with various types of stones and with many different causes. At the Kidney Stone Center of Maine, we utilize state of the art expertise, technology, and technique to successfully treat stones.

After successful treatment, most patients would prefer to avoid another kidney stone attack in the future and with careful evaluation and diagnostic testing, recurrent stone growth can be slowed, delayed, or even completed prevented in many patients.

What Causes Kidney Stones?

Stones form for a potential number of reasons:

  • Dehydration – whether from inadequate fluid intake or loss of fluids
  • Geography – hot, humid climates, such as the “kidney stone belt”
  • Genetics – patients with family history of stones
  • Diet – certain foods can predispose patients to increased risk
  • Medical problems – hyperparathyroidism, gout, chronic diarrhea and GI problems that can affect mineral and fluid absorption
  • Medications – Certain protease inhibitors, antibiotics, diuretics, and others

What Symptoms are caused by Kidney Stones?

Many stones do not cause symptoms at all. However, once a kidney stone migrates from the kidney into the ureter, it blocks the flow of urine which can result in excruciating flank pain. Many think that this pain is caused by a scratching of the stone as it passes through the ureter. In fact, most of the pain is caused by obstruction of the ureter, causing a backup of urine into the kidney with resultant stretching and dilation of the tissue.

Nausea and vomiting are often present during acute episodes.

Some patients may have an urgency to urinate or blood in the urine. Some patients may even have no symptoms at all.

Types of Kidney Stones

High levels of certain minerals in the urine can form into crystals, eventually leading to stone formation in the kidney, a condition called nephrolithiasis.

There are various types of kidney stones:

  1. Calcium oxalate stones (80%)
  2. Calcium phosphate
  3. Uric acid stones (10%)
  4. Struvite, cystine, mixed, triamterene and other very rare types

Treatment of Kidney Stones

The urologists at the Kidney Stone Center of Maine offer expert the full scope of minimally invasive treatment options customized to your needs.

  1. Observation – when stones are small and sitting up in the kidney without causing symptoms, they can often be monitored. However, some patient’s choose to treat them to ensure they don’t have problems at inopportune times (travel, etc.)

2. Trial of Passage – occasionally stones are migrating from the kidney to the bladder.

3. Shockwave lithotripsy – minimally invasive therapy useful for select patients using targeted soundwaves to cause a stone to break up.

4. Ureteroscopy with laser lithotripsy – minimally invasive treatment option using wires, a tiny camera (ureteroscope), and a precise yet powerful laser fiber.

5. Percutaneous nephrolithotomy (PCNL/mini-PCNL) – treatment options where a tiny incision is made through the back which allows for treatment of larger stones unable to be treated by less invasive means.

6. Double J ureteral stents – At times, kidney stones may be infected which can lead to sepsis and even death. In other situations, pain from the stones can be so severe that pain medication cannot relieve the pain. Additionally, for patients with impaired kidney function or a solitary kidney, obstruction by a stone can cause worsening of kidney function. In all of these situations, it may be appropriate to simply place a ureteral stent (and leave the stone temporarily untreated) in order to stabilize the patient’s condition and allow time for recovery. This often requires a second procedure at some point in the future to treat the stone.

Kidney Stone Prevention

Even though many treatment options and advanced equipment are available to successfully treat kidney stones, our goal is to help patients avoid recurrent stones. To achieve this, your Urologist might recommend a change in your diet or a special medication.

Calcium stone formers may be recommended to increase fluid intake, avoid excess dietary sodium, decrease oxalate intake and avoid excessive calcium supplements. However, keep in mind that we do not recommend restricting dairy calcium. The dairy calcium has the ability to bind oxalate in the intestines and pass out in the feces. If dairy calcium is not available, the oxalate in the gut will be absorbed and sent to the kidneys, where it can combine with calcium in the urine to form stones. If calcium supplements are necessary for osteoporosis, or other reasons, calcium citrate is recommended over calcium carbonate in stone formers.

For recurrent stone formers, who have failed dietary measures, we have developed a kidney stone prevention clinic. This allows us to more aggressively evaluate the patients with various blood levels of calcium, potassium, uric acid, and others, depending on the situation. We evaluate a detailed medical and dietary history. We may also obtain 24-hour urine collections for metabolic evaluation. Medications, such as potassium citrate, may be utilized, as well as others.