The book: "Stones"
Causes and Symptoms (Magill’s Medical Guide, Sixth Edition)
Stones may form in the kidneys, ureters, bladder, and gallbladder. Kidney and ureter stones are typically calcium-based, while bladder stones are most frequently composed of uric acid (a by-product of protein metabolism) or struvite (a result of chronic urinary infection). Gallstones contain very little calcium; they are primarily composed of cholesterol.
The symptoms that accompany urinary stone disease are dependent on the location of the stone, the size of the stone, how long the stone has been present, whether infection is associated with the stone, and the degree of obstruction to urinary flow caused by the stone. Urine, which is produced by the kidneys, located beneath the ribs of the back, is collected into a structure just outside the kidney known as the renal pelvis. From the renal pelvis, urine passes into a thin narrow tube called the ureter and travels a relatively long distance to the urinary bladder. It is easy to envision how a stone traveling along such a narrow, long tube can get stuck and dam the further flow of urine.
Stones caught in the renal pelvis, prior to entry into the ureter, generally cause an intermittent, sharp pain in the back or side. Stones that pass into the ureter can cause pain in the back as well as points distant from the urinary system (the groin, the lower abdomen, and the testicles and penis in men); this phenomenon is known as referred pain. Occasionally, stones in the...
(The entire section is 1145 words.)
Treatment and Therapy (Magill’s Medical Guide, Sixth Edition)
Treatment of any stone depends on the location of the stone, its size, the time it has been in place, and any complicating issues such as infection. The methods for treatment are broad, and the specific means by which a stone should be removed are often debated among the experts in this field. Some stones—especially if they are small, cause no pain, and are not significantly obstructing—are given a chance to pass on their own, a treatment termed watchful waiting. The most frequent noninvasive means to treat a small stone located in the urinary tract above the pelvic bone is extracorporeal shock-wave lithotripsy (ESWL). This procedure involves the use of high-energy sound waves created by a machine outside the body and focused through the skin onto the stone. These sound waves break the stone into fine sand, which passes in the urine without symptoms. This is frequently the best method to deal with stones in elderly patients who have other medical problems that can make surgical means of removing a stone risky. Endoscopic removal of a stone involves the use of small telescopes passed into the urinary tract either through the urethra or through the back directly into the kidney. Different means of fragmenting the stone into smaller pieces for direct removal are then employed through the telescopes. This method is highly successful and often used for larger stones. Like ESWL, this low-invasive, endoscopic means of removing...
(The entire section is 588 words.)
Perspective and Prospects (Magill’s Medical Guide, Sixth Edition)
While there is no evidence of increased incidence of urinary stones with increasing age, stones of the biliary tract (cholelithiasis) do increase with age, affecting approximately 33 percent of the U.S. population over seventy years old.
Kidney stones or stones in the urinary tract affect 5 to 10 percent of the general population of the United States. The likelihood of a person to form a stone for the first time in their life decreases with advancing age. In people who have a prior history of urinary stone formation, however, the incidence, recurrence, and severity of urinary stone disease is similar between the geriatric and younger populations. The composition of urinary stones in the older population is no different from that of those found in younger patients; however, the underlying urinary abnormality leading to the stone formation is different. More frequently, urinary stones in the elderly are caused by high uric acid levels and low citrate levels in the urine. Similar difficulties in the disposal of protein metabolites can lead to gouty arthritis.
(The entire section is 170 words.)
For Further Information: (Magill’s Medical Guide, Sixth Edition)
Gillenwater, Jay Y., et al., eds. Adult and Pediatric Urology. 4th ed. Philadelphia: Lippincott Williams & Wilkins, 2002. A three-volume clinical set that covers a range of urologic diseases and disorders in adults and children.
Moran, M. E. “Uric Acid Stone Disease.” Frontiers in Bioscience 8 (September, 2003): 1339-1355. Details the rise of uric stone formation throughout the world, examining its history, diagnosis, treatments, and risk factors.
Saunders, Carol S. “Urolithiasis: New Tools for Diagnosis and Treatment.” Patient Care 33, no. 15 (September 30, 1999): 28-44. Noncontrast helical CT has replaced IV pyelography as first-line imaging for suspected acute renal colic, and treatment decisions have been simplified with new guidelines. This and other advances in prevention are discussed.
Walsh, Patrick C., et al., eds. Campbell-Walsh Urology. 4 vols. 9th ed. Philadelphia: Saunders/Elsevier, 2007. This edition of a classic urology text maintains its encyclopedic approach while following a new organ systems orientation. Halftone illustrations and contributions by multiple authors. Includes a CD-ROM.
(The entire section is 153 words.)