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Global Lithotripsy Services |
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UPDATE ON STONE MANAGEMENT David T. Bolong, M.D., DPBU, FPCS The diagnosis and treatment of urinary tract calculi in the Philippines has improved dramatically over the past five years. Some of the biggest gains made have been at the primary care level, where stone patients are diagnosed first. The Family Physician plays an important role in stone management, and it is important that primary care physicians know and understand guidelines for the diagnosis of stone disease and available treatment options. The following paper is intended to help the primary care physician diagnose stone disease and prescribe the right treatment based on that diagnosis. Statistically, 12% of men and 5% of women will suffer from renal stones by age 70. Incidence rates for Filipinos are not available; however, incidence rates among adults in North America are 2-3%. Recurrence rates range from 7% annually and increase to 50% over 10 years. Fortunately, 70% of symptomatic calculi pass spontaneously while only 30% require some sort of medical intervention. Diagnosing urolithiasis is relatively easy in most cases.
A patient describing these symptoms is most probably suffering from renal colic caused by the passage of the stone through the urinary tract. If the patient has a history of stone disease in the family, or performs outdoor labor with limited fluid intake, the chances of stone disease are greater. Note: If fever is present, it implies infection. In these cases, septicemia is a clear and present health threat and should be taken seriously.
Laboratory analysis will help the physician deduce the presence of a stone and the type of stone present. The normal laboratory work-up includes:
The following table shows normal values for three specific lab tests.
If the physical examination and lab results indicate the presence of a stone, then the next step is an IVP (intravenous pyelogram) – the mainstay in the diagnosis of urolithiasis. A KUB is acceptable and widely used, especially for high risk patients or patients with high creatinine levels. An IVP provides valuable information on the type of stone (by degree of opacity), the position of the stone in the urinary tract, damage caused by the offending stone, presence of hydronephrosis, and any anatomical anomalies inducing stone formation. The IVP will also provide the physician valuable information on how best to treat the offending stone.
If a stone is present, the physician should discuss treatment options with patient based on the evidence in hand. Provided that no infection is present, the physician can reasonably wait up to 4 weeks before prescribing more aggressive therapies. However, that decision depends largely on the patient and the size and type of stone. Large stones or stones causing obstruction should be dealt with quickly to avoid further complications. Studies have shown that renal deterioration increases over time – sometimes as fast as 18-24 hours – and some irreversible loss can occur at 5-14 days with very slight recovery after 16 weeks. Recommended for small stones (< 7 mm) and uric acid stones. The objectives of medical management are: pain management, inducing spontaneous stone passage and stone dissolution. A stone measuring less than 5 mm. located in the distal ureter has a 90% chance of spontaneous passage, whereas a similar size stone in the upper-third has an 80% chance.
In all cases, hydration is key and the patient should be drinking a minimum of 2 liters of water per day!
Recommended for ureteral stones in the middle and upper third and renal stones measuring between 5 mm and 25 mm. ESWL is the recommended therapy for 80% of all stones, because it is safe, quick, effective and non-invasive. The lithotripsy procedure is usually performed on an outpatient basis under sedo-analgesia in approximately 90 minutes. In most cases, the patient is back to work the very next day. Lithotripsy works by focusing acoustic shock waves directly on the stone. Over the course of treatment, the stone disintegrates into very small sand-like particles, which are then discharged by normal peristalsis. The effectiveness of ESWL depends largely on the composition and size of the stone, as well as the type of equipment used. For stones measuring < 2.5 cm, success rates are around 90%. Absolute contraindications for ESWL are pregnancy, urinary tract infection, uncontrolled bleeding and hypertension. Relative contraindications for ESWL are very large stones, severely dilated collecting systems, protein matrix stones, obese patients, and patients with pacemakers. Recommended for stones in the lower and middle third of the ureter. Endoscopic retrieval involves retrograde visualization of the urinary tract through the urethra. Ancillary lithotripters (i.e. lasers, ultrasound, electrohydraulic) help break the stones into small pieces so that they can be retrieved mechanically. This is an in-patient procedure performed under general anesthesia. Stone free rates using endoscopy are usually very good, but effectiveness depends largely on the experience of the operator. Complications include inadvertent perforations, bleeding and stricture formation. Recommended for large staghorn calculi, multiple renal stones, large lower pole kidney stones and calculus with associated renal outlet obstruction. PCNL is another form of endoscopic retrieval, which involves making a 1 cm opening to access the kidney. The kidney is perforated using an 18 gauge needle and then dilated to allow the use of a nephroscope to remove the offending stone(s). Generally, patients are hospitalized for several days and may have a nephrostomy tube left in the kidney during the healing process. Stone free rates are very good, but complications exist and results vary depending on the experience of the operator. Recommended for patients with very large staghorn calculi and for some ureteral calculi. Open surgery still has a role in stone management, especially for staghorn calculi and stones in the lower pole. Open surgery can be performed in virtually any part of the country while endoscopy and lithotripsy are confined to tertiary centers. Stone free rates are very good, but complications and morbidity rates are the highest, and recovery time is the longest.
Today, the vast majority of stone cases can be treated non-surgically. Early diagnosis and treatment is in the best interest of the patient. Avoiding or prolonging treatment, more often than not, means greater health risks, more complications and higher costs to the patient. The general advice to stone formers is to drink plenty of water, restrict sodium and glucose intake, maintain a high potassium diet, including high citrus fruit intake, and avoid fatty or salty meats. |
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