Lithotripsy Health Dictionary

Extracorporeal shock wave lithotripsy (see lithotripsy).... eswl

Ultrasound, or ultrasonic, waves comprise very-high-frequency sound waves above 20,000 Hz that the human ear cannot hear. Ultrasound is widely used for diagnosis and also for some treatments. In OBSTETRICS, ultrasound can assess the stage of pregnancy and detect abnormalities in the FETUS (see below). It is a valuable adjunct in the investigation of diseases in the bladder, kidneys, liver, ovaries, pancreas and brain (for more information on these organs and their diseases, see under separate entries); it also detects thromboses (clots) in blood vessels and enables their extent to be assessed. A non-invasive technique that does not need ionising radiation, ultrasound is quick, versatile and relatively inexpensive, with scans being done in any plane of the body. There is little danger to the patient or operator: unlike, for example, XRAYS, ultrasound investigations can be repeated as needed. A contrast medium is not required. Its reliability is dependent upon the skill of the operator.

Ultrasound is replacing ISOTOPE scanning in many situations, and also RADIOGRAPHY. Ultrasound of the liver can separate medical from surgical JAUNDICE in approximately 97 per cent of patients; it is very accurate in detecting and de?ning cystic lesions of the liver, but is less accurate with solid lesions – and yet will detect 85 per cent of secondary deposits (this is less than COMPUTED TOMOGRAPHY [CT] scanning). It is very accurate in detecting gall-stones (see GALL-BLADDER, DISEASES OF) and more accurate than the oral cholecystogram. It is useful as a screening test for pancreatic disease and can di?erentiate carcinoma of the pancreas from chronic pancreatitis with 85 per cent accuracy.

Ultrasound is the ?rst investigation indicated in patients presenting with renal failure, as it can quickly determine the size and shape of the kidney and whether there is any obstruction to the URETER. It is very sensitive to the presence of dilatation of the renal tract and will detect space-occupying lesions, di?erentiating cysts and tumours. It can detect also obstruction of the ureter due to renal stones by showing dilatations of the collecting system and the presence of the calculus. Adrenal (see ADRENAL GLANDS) tumours can be demonstrated by ultrasound, although it is less accurate than CT scanning.

The procedure is now the ?rst test for suspected aortic ANEURYSM and it can also show the presence of clot and delineate the true and false lumen. It is good at demonstrating subphrenic and subhepatic abscesses (see ABSCESS) and will show most intra-abdominal abscesses; CT scanning is however better for the retroperitoneal region. It has a major application in thyroid nodules as it can di?erentiate cystic from solid lesions and show the multiple lesions characteristic of the nodular GOITRE (see also THYROID GLAND, DISEASES OF). It cannot differentiate between a follicular adenoma and a carcinoma, as both these tumours are solid; nor can it demonstrate normal parathyroid glands. However, it can identify adenomas provided that they are more than 6 mm in diameter. Finally, ultrasound can di?erentiate masses in the SCROTUM into testicular and appendicular, and it can demonstrate impalpable testicular tumours. This is important as 15 per cent of testicular tumours metastasise whilst they are still impalpable.

Ultrasonic waves are one of the constituents in the shock treatment of certain types of gallstones and CALCULI in the urinary tract (see LITHOTRIPSY). They are also being used in the treatment of MENIÈRE’S DISEASE and of bruises and strains. In this ?eld of physiotherapy, ultrasonic therapy is proving of particular value in the treatment of acute injuries of soft tissue. If in such cases it is used immediately after the injury, or as soon as possible thereafter, prompt recovery is facilitated. For this reason it is being widely used in the treatment of sports injuries (see also SPORTS MEDICINE). The sound waves stimulate the healing process in damaged tissue.

Doppler ultrasound is a technique which shows the presence of vascular disease in the carotid and peripheral vessels, as it can detect the reduced blood ?ow through narrowed vessels.

Ultrasound in obstetrics Ultrasound has particular applications in obstetrics. A fetus can be seen with ultrasound from the seventh week of pregnancy, and the fetal heart can be demonstrated at this stage. Multiple pregnancy can also be diagnosed at this time by the demonstration of more than one gestation sac containing a viable fetus. A routine obstetric scan is usually performed between the 16th and 18th week of pregnancy when the fetus is easily demonstrated and most photogenic. The fetus can be measured to assess the gestational age, and the anatomy can also be checked. Intra-uterine growth retardation is much more reliably diagnosed by ultrasound than by clinical assessment. The site of the placenta can also be recorded and multiple pregnancies will be diagnosed at this stage. Fetal movements and even the heartbeat can be seen. A second scan is often done between the 32nd and 34th weeks to assess the position, size and growth rate of the baby. The resolution of equipment now available enables pre-natal diagnosis of a wide range of structural abnormalities to be diagnosed. SPINA BIFIDA, HYDROCEPHALUS and ANENCEPHALY are probably the most important, but other anomalies such as multicystic kidney, achondroplasia and certain congenital cardiac anomalies can also be identi?ed. Fetal gender can be determined from 20 weeks of gestation. Ultrasound is also useful as guidance for AMNIOCENTESIS.

In gynaecology, POLYCYSTIC OVARY SYNDROME can readily be detected as well as FIBROID and ovarian cysts. Ultrasound can monitor follicular growth when patients are being treated with infertility drugs. It is also useful in detecting ECTOPIC PREGNANCY. (See also PREGNANCY AND LABOUR.)... ultrasound

The removal of gall-stones from the gallbladder or bile ducts (see GALL-BLADDER, DISEASES OF), when CHOLECYSTECTOMY or LITHOTRIPSY are inappropriate or not possible. It involves a cholecystomy, an operation to open the gall-bladder.... cholelithotomy

The gall-bladder rests on the underside of the LIVER and joins the common hepatic duct via the cystic duct to form the common BILE DUCT. The gall-bladder acts as a reservoir and concentrator of BILE, alterations in the composition of which may result in the formation of gallstones, the most common disease of the gallbladder.

Gall-stones affect 22 per cent of women and 11 per cent of men. The incidence increases with age, but only about 30 per cent of those with gall-stones undergo treatment as the majority of cases are asymptomatic. There are three types of stone: cholesterol, pigment and mixed, depending upon their composition; stones are usually mixed and may contain calcium deposits. The cause of most cases is not clear but sometimes gall-stones will form around a ‘foreign body’ within the bile ducts or gall-bladder, such as suture material. BILIARY COLIC Muscle ?bres in the biliary system contract around a stone in the cystic duct or common bile duct in an attempt to expel it. This causes pain in the right upper quarter of the abdomen, with nausea and occasionally vomiting. JAUNDICE Gall-stones small enough to enter the common bile duct may block the ?ow of bile and cause jaundice. ACUTE CHOLECYSTITIS Blockage of the cystic duct may lead to this. The gall-bladder wall becomes in?amed, resulting in pain in the right upper quarter of the abdomen, fever, and an increase in the white-blood-cell count. There is characteristically tenderness over the tip of the right ninth rib on deep inhalation (Murphy’s sign). Infection of the gall-bladder may accompany the acute in?ammation and occasionally an EMPYEMA of the gall-bladder may result. CHRONIC CHOLECYSTITIS A more insidious form of gall-bladder in?ammation, producing non-speci?c symptoms of abdominal pain, nausea and ?atulence which may be worse after a fatty meal.

Diagnosis Stones are usually diagnosed on the basis of the patient’s reported symptoms, although asymptomatic gall-stones are often an incidental ?nding when investigating another complaint. Con?rmatory investigations include abdominal RADIOGRAPHY – although many gall-stones are not calci?ed and thus do not show up on these images; ULTRASOUND scanning; oral CHOLECYSTOGRAPHY – which entails a patient’s swallowing a substance opaque to X-rays which is concentrated in the gall-bladder; and endoscopic retrograde cholangiopancreatography (ERCP) – a technique in which an ENDOSCOPE is passed into the duodenum and a contrast medium injected into the biliary duct.

Treatment Biliary colic is treated with bed rest and injection of morphine-like analgesics. Once the pain has subsided, the patient may then be referred for further treatment as outlined below. Acute cholecystitis is treated by surgical removal of the gall-bladder. There are two techniques available for this procedure: ?rstly, conventional cholecystectomy, in which the abdomen is opened and the gall-bladder cut out; and, secondly, laparoscopic cholecystectomy, in which ?breoptic instruments called endoscopes (see FIBREOPTIC ENDOSCOPY) are introduced into the abdominal cavity via several small incisions (see MINIMALLY INVASIVE SURGERY (MIS)). Laparoscopic surgery has the advantage of reducing the patient’s recovery time. Gall-stones may be removed during ERCP; they can sometimes be dissolved using ultrasound waves (lithotripsy) or tablet therapy (dissolution chemotherapy). Pigment stones, calci?ed stones or stones larger than 15 mm in diameter are not suitable for this treatment, which is also less likely to succeed in the overweight patient. Drug treatment is prolonged but stones can disappear completely after two years. Stones may re-form on stopping therapy. The drugs used are derivatives of bile salts, particularly chenodeoxycholic acid; side-effects include diarrhoea and liver damage.... gall-bladder, diseases of

Diseases affecting the kidneys can be broadly classi?ed into congenital and genetic disorders; autoimmune disorders; malfunctions caused by impaired blood supply; infections; metabolic disorders; and tumours of the kidney. Outside factors may cause functional disturbances – for example, obstruction in the urinary tract preventing normal urinary ?ow may result in hydronephrosis (see below), and the CRUSH SYNDROME, which releases proteins into the blood as a result of seriously damaged muscles (rhabdomyolosis), can result in impaired kidney function. Another outside factor, medicinal drugs, can also be hazardous to the kidney. Large quantities of ANALGESICS taken over a long time damage the kidneys and acute tubular NECROSIS can result from certain antibiotics.

K

Diagram of glomerulus (Malpighian corpuscle).

Fortunately the body has two kidneys and, as most people can survive on one, there is a good ‘functional reserve’ of kidney tissue.

Symptoms Many patients with kidney disorders do not have any symptoms, even when the condition is quite advanced. However,

others experience loin pain associated with obstruction (renal colic) or due to infection; fevers; swelling (oedema), usually of the legs but occasionally including the face and arms; blood in the urine (haematuria); and excess quantities of urine (polyuria), including at night (nocturia), due to failure of normal mechanisms in the kidney for concentrating urine. Patients with chronic renal failure often have very di?use symptoms including nausea and vomiting, tiredness due to ANAEMIA, shortness of breath, skin irritation, pins and needles (paraesthesia) due to damage of the peripheral nerves (peripheral neuropathy), and eventually (rarely seen nowadays) clouding of consciousness and death.

Signs of kidney disease include loin tenderness, enlarged kidneys, signs of ?uid retention, high blood pressure and, in patients with end-stage renal failure, pallor, pigmentation and a variety of neurological signs including absent re?exes, reduced sensation, and a coarse ?apping tremor (asterixis) due to severe disturbance of the body’s normal metabolism.

Renal failure Serious kidney disease may lead to impairment or failure of the kidney’s ability to ?lter waste products from the blood and excrete them in the urine – a process that controls the body’s water and salt balance and helps to maintain a stable blood pressure. Failure of this process causes URAEMIA – an increase in urea and other metabolic waste products – as well as other metabolic upsets in the blood and tissues, all of which produce varying symptoms. Failure can be sudden or develop more slowly (chronic). In the former, function usually returns to normal once the underlying cause has been treated. Chronic failure, however, usually irreparably reduces or stops normal function.

Acute failure commonly results from physiological shock following a bad injury or major illness. Serious bleeding or burns can reduce blood volume and pressure to the point where blood-supply to the kidney is greatly reduced. Acute myocardial infarction (see HEART, DISEASES OF) or pancreatitis (see PANCREAS, DISORDERS OF) may produce a similar result. A mismatched blood transfusion can produce acute failure. Obstruction to the urine-?ow by a stone (calculus) in the urinary tract, a bladder tumour or an enlarged prostate can also cause acute renal failure, as can glomerulonephritis (see below) and the haemolytic-uraemia syndrome.

HYPERTENSION, DIABETES MELLITUS, polycystic kidney disease (see below) or AMYLOIDOSIS are among conditions that cause chronic renal failure. Others include stone, tumour, prostatic enlargement and overuse of analgesic drugs. Chronic failure may eventually lead to end-stage renal failure, a life-threatening situation that will need DIALYSIS or a renal transplant (see TRANSPLANTATION).

Familial renal disorders include autosomal dominant inherited polycystic kidney disease and sex-linked familial nephropathy. Polycystic kidney disease is an important cause of renal failure in the UK. Patients, usually aged 30–50, present with HAEMATURIA, loin or abdominal discomfort or, rarely, urinary-tract infection, hypertension and enlarged kidneys. Diagnosis is based on ultrasound examination of the abdomen. Complications include renal failure, hepatic cysts and, rarely, SUBARACHNOID HAEMORRHAGE. No speci?c treatment is available. Familial nephropathy occurs more often in boys than in girls and commonly presents as Alport’s syndrome (familial nephritis with nerve DEAFNESS) with PROTEINURIA, haematuria, progressing to renal failure and deafness. The cause of the disease lies in an absence of a speci?c ANTIGEN in a part of the glomerulus. The treatment is conservative, with most patients eventually requiring dialysis or transplantation.

Acute glomerulonephritis is an immune-complex disorder due to entrapment within glomerular capillaries of ANTIGEN (usually derived from B haemolytic streptococci – see STREPTOCOCCUS) antibody complexes initiating an acute in?ammatory response (see IMMUNITY). The disease affects children and young adults, and classically presents with a sore throat followed two weeks later by a fall in urine output (oliguria), haematuria, hypertension and mildly abnormal renal function. The disease is self-limiting with 90 per cent of patients spontaneously recovering. Treatment consists of control of blood pressure, reduced ?uid and salt intake, and occasional DIURETICS and ANTIBIOTICS.

Chronic glomerulonephritis is also due to immunological renal problems and is also classi?ed by taking a renal biopsy. It may be subdivided into various histological varieties as determined by renal biospy. Proteinuria of various degrees is present in all these conditions but the clinical presentations vary, as do their treatments. Some resolve spontaneously; others are treated with steroids or even the cytotoxic drug CYCLOPHOSPHAMIDE or the immunosuppressant cyclosporin. Prognoses are generally satisfactory but some patients may require renal dialysis or kidney transplantation – an operation with a good success rate.

Hydronephrosis A chronic disease in which the kidney becomes greatly distended with ?uid. It is caused by obstruction to the ?ow of urine at the pelvi-ureteric junction (see KIDNEYS – Structure). If the ureter is obstructed, the ureter proximal to the obstruction will dilate and pressure will be transmitted back to the kidney to cause hydronephrosis. Obstruction may occur at the bladder neck or in the urethra itself. Enlargement of the prostate is a common cause of bladder-neck obstruction; this would give rise to hypertrophy of the bladder muscle and both dilatation of the ureter and hydronephrosis. If the obstruction is not relieved, progressive destruction of renal tissue will occur. As a result of the stagnation of the urine, infection is probable and CYSTITIS and PYELONEPHRITIS may occur.

Impaired blood supply may be the outcome of diabetes mellitus and physiological shock, which lowers the blood pressure, also affecting the blood supply. The result can be acute tubular necrosis. POLYARTERITIS NODOSA and SYSTEMIC LUPUS ERYTHEMATOSUS (SLE) may damage the large blood vessels in the kidney. Treatment is of the underlying condition.

Infection of the kidney is called pyelonephritis, a key predisposing factor being obstruction of urine ?ow through the urinary tract. This causes stagnation and provides a fertile ground for bacterial growth. Acute pyelonephritis is more common in women, especially during pregnancy when bladder infection (CYSTITIS) spreads up the ureters to the kidney. Symptoms are fever, malaise and backache. Antibiotics and high ?uid intake are the most e?ective treatment. Chronic pyelonephritis may start in childhood as a result of congenital deformities that permit urine to ?ow up from the bladder to the kidney (re?ux). Persistent re?ux leads to recurrent infections causing permanent damage to the kidney. Specialist investigations are usually required as possible complications include hypertension and kidney failure.

Tumours of the kidney are fortunately rare. Non-malignant ones commonly do not cause symptoms, and even malignant tumours (renal cell carcinoma) may be asymptomatic for many years. As soon as symptoms appear – haematuria, back pain, nausea, malaise, sometimes secondary growths in the lungs, bones or liver, and weight loss – urgent treatment including surgery, radiotherapy and chemotherapy is necessary. This cancer occurs mostly in adults over 40 and has a hereditary element. The prognosis is not good unless diagnosed early. In young children a rare cancer called nephroblastoma (Wilm’s tumour) can occur; treatment is with surgery, radiotherapy and chemotherapy. It may grow to a substantial size before being diagnosed.

Cystinuria is an inherited metabolic defect in the renal tubular reabsorption of cystine, ornithine, lysine and arginine. Cystine precipitates in an alkaline urine to form cystine stones. Triple phosphate stones are associated with infection and may develop into a very large branching calculi (staghorn calculi). Stones present as renal or ureteric pain, or as an infection. Treatment has undergone considerable change with the introduction of MINIMALLY INVASIVE SURGERY (MIS) and the destruction of stone by sound waves (LITHOTRIPSY).... kidneys, diseases of

More popularly called ‘keyhole surgery’, MIS is surgical intervention, whether diagnostic or curative, that causes patients the least possible physical trauma. It has revolutionised surgery, growing from a technique used by gynaecologists, urologists and innovative general surgeons to one regularly used in general surgery, GYNAECOLOGY, UROLOGY, thoracic surgery, orthopaedic surgery (see ORTHOPAEDICS) and OTORHINOLARYNGOLOGY.

MIS is commonly carried out by means of an operating laparoscope (a type of ENDOSCOPE) that is slipped through a small incision in the skin. MIS now accounts for around 50 per cent

of all operations carried out in the UK. A small attachment on the end of the laparoscope provides an image that can be magni?ed on a screen, leaving the surgeon’s hands free to operate while his assistant operates the laparoscope. Halogen bulbs, ?breoptic cables and rod lenses have all contributed to the technical advancement of laparoscopes. Operations done in this manner include extracorporeal shock-wave LITHOTRIPSY for stones in the gall-bladder, biliary ducts and urinary system; removal of the gall-bladder; appendicectomy; removal of the spleen and adrenal glands; and thoracic sympathectomy. MIS is also used to remove cartilage or loose pieces of bone in the knee-joint.

This method of surgery usually means that patients can be treated on a day or overnight basis, allowing them to resume normal activities more quickly than with conventional surgery. It is safer and lessens the trauma and shock for patients needing surgery. MIS is also more cost e?ective, allowing hospitals to treat more patients in a year. Surgeons undertake special training in the use of MIS, a highly skilled technique, before they are permitted to use the procedures on patients. The use of MIS for hernia repair, colon surgery and repairs of duodenal perforations is under evaluation and its advantages will be enhanced by the development of robotic surgical techniques.... minimally invasive surgery (mis)

A ?exible or rigid endoscopic instrument (see ENDOSCOPE) that is inserted (via the URINARY BLADDER) into the URETER and up into the pelvis of the kidney (see KIDNEYS). The instrument is commonly used to identify a stone in the ureter and to remove it under vision with forceps or a stone basket. If the stone is large it is broken into fragments, using an ultrasound or electrohydraulic LITHOTRIPSY probe that is inserted through the instrument.... ureteroscope

Surgical removal of a calculus (stone) from part of the urinary tract.

The procedure is only performed for large stones; smaller stones are usually crushed and removed using cystoscopy, or pulverized ultrasonically by lithotripsy.... lithotomy

The machine used in extracorporeal shock-wave lithotripsy (ESWL) to disintegrate small calculi (stones).... lithotripter

The surgical removal of a calculus (stone) from the kidney.

Nephrolithotomy may be performed through an abdominal incision, or via a puncture incision in the back. Large

calculi may need to be broken up before removal. Other methods of removal are pyelolithotomy and lithotripsy.... nephrolithotomy

An operation performed to remove a kidney stone (see calculus, urinary tract).

Pyelolithotomy has been largely replaced by other procedures, such as lithotripsy, which uses ultrasonic waves to break up the stones.... pyelolithotomy

Diseases of the URINARY BLADDER are diagnosed by the patient’s symptoms and signs, examination of the URINE, and using investigations such as X-RAYS and ULTRASOUND scans. The interior of the bladder can be examined using a cystoscope, which is a ?breoptic endoscope (see FIBREOPTIC ENDOSCOPY) that is passed into the bladder via the URETHRA.

Cystitis Most cases of cystitis are caused by bacteria which have spread from the bowel, especially Escherichia coli, and entered the bladder via the urethra. Females are more prone to cystitis than are males, owing to their shorter urethra which allows easier entry for bacteria. Chronic or recurrent cystitis may result in infection spreading up the ureter to the kidney (see KIDNEY, DISEASES OF).

Symptoms Typically there is frequency and urgency of MICTURITION, with stinging and burning on passing urine (dysuria), which is often smelly or bloodstained. In severe infection patients develop fever and rigors, or loin pain. Before starting treatment a urine sample should be obtained for laboratory testing, including identi?cation of the invading bacteria.

Treatment This includes an increased ?uid intake, ANALGESICS, doses of potassium citrate to make the urine alkaline to discourage bacterial growth, and an appropriate course of ANTIBIOTICS once a urine sample has been ana-lysed in the laboratory to con?rm the diagnosis and determine what antibiotics the causative organism is likely to respond to.

Stone or calculus The usual reason for the formation of a bladder stone is an obstruction to the bladder out?ow, which results in stagnant residual urine – ideal conditions for the crystallisation of the chemicals that form stones – or from long-term indwelling CATHETERS which weaken the natural mechanical protection against bacterial entry and, by bruising the lining tissues, encourage infection.

Symptoms The classic symptom is a stoppage in the ?ow of urine during urination, associated with severe pain and the passage of blood.

Treatment This involves surgical removal of the stone either endoscopically (litholapaxy); by passing a cystoscope into the bladder via the urethra and breaking the stone; or by LITHOTRIPSY in which the stone (or stones) is destroyed by applying ultrasonic shock waves. If the stone cannot be destroyed by these methods, the bladder is opened and the stone removed (cystolithotomy).

Cancer Cancer of the bladder accounts for 7 per cent of all cancers in men and 2·5 per cent in women. The incidence increases with age, with smoking and with exposure to the industrial chemicals, beta-napththylamine and benzidine. In 2003, 2,884 men and 1,507 women died of bladder cancer in England and Wales.

Symptoms The classical presenting symptom of a bladder cancer is the painless passing of blood in the urine – haematuria. All patients with haematuria must be investigated with an X-ray of their kidneys, an INTRAVENOUS PYELOGRAM (UROGRAM) and a cystoscopy.

Treatment Super?cial bladder tumours on the lining of the bladder can be treated by local removal via the cystoscope using DIATHERMY (cystodiathermy). Invasive cancers into the bladder muscle are usually treated with RADIOTHERAPY, systemic CHEMOTHERAPY or surgical removal of the bladder (cystectomy). Local chemotherapy may be useful in some patients with multiple small tumours.... urinary bladder, diseases of

A stone in the kidneys, ureters, or bladder formed from substances in urine.

Most urinary tract stones are composed of calcium oxalate or other salts crystallized from the urine. These may be associated with a diet rich in oxalic acid (found in leafy vegetables and coffee); high levels of calcium in the blood as a result of hyperparathyroidism; or chronic dehydration. Other types of stone are associated with gout and some cancers. An infective stone is usually a result of chronic urinary tract infection.

In developing countries, bladder stones usually occur as a result of dietary deficiencies. In developed countries, they are usually caused by an obstruction to urine flow from the bladder and/or a longstanding urinary tract infection.

The most common symptom of a stone in the kidney or ureter is renal colic (a severe pain in the loin) that may cause nausea and vomiting. There may be haematuria (blood in the urine). A bladder stone is usually indicated by difficulty in passing urine. The site of the stone can usually be confirmed by intravenous or retrograde urography.

Renal colic is treated with bed rest and an opioid analgesic (painkiller).

With an adequate fluid intake, small stones are usually passed in the urine without problems.

The first line of treatment for larger stones is lithotripsy, which uses ultrasonic or shock waves to disintegrate the stones.

Alternatively, cytoscopy can be used to crush and remove stones in the bladder and lower ureter.

In some cases, surgery may be needed.... calculus, urinary tract

The surgical removal of a stone (see calculus, urinary tract) stuck in a ureter.

It is not commonly needed because lithotripsy and cystoscopy can be used to deal with stones.... ureterolithotomy

(lithotripsy) n. the operation of crushing a stone in the bladder, using an instrument called a lithotrite. The small fragments of stone can then be removed by irrigation and suction.... litholapaxy

a technique for removing a stone from the ureter. It consists of ‘pushing’ the stone back into the renal pelvis, where it can be destroyed by *lithotripsy (‘bang’).... push-bang technique

n. a stone (calculus) in a salivary gland or duct, most often the duct of the submandibular gland. The flow of saliva is obstructed, causing swelling and intense pain. Treatment is primarily by surgery to remove the stone or the whole gland but in a few cases *lithotripsy is used.... sialolith

Lumps of solid matter found in the gallbladder, or in the bile ducts. Gallstones are composed mainly of cholesterol and bile pigments from the breakdown of red blood cells. They develop when there is a disturbance in the chemical composition of bile.

Gallstones are rare in childhood and become increasingly common with age. Women are affected more than men. Risk factors include a high-fat diet and being overweight.

Most gallstones cause no symptoms. When symptoms do occur, they often begin when a stone gets stuck in the duct leading from the gallbladder, causing biliary colic and nausea. Gallstones may cause indigestion and flatulence. Possible complications are cholecystitis and bile duct obstruction.Diagnosis is by ultrasound scanning, X-ray oral cholecystography, or cholangiography.

Stones that are not causing symptoms are usually left alone.

In other cases, the gallbladder and stones may be removed by cholecystectomy.

Ultrasonic shock waves (see lithotripsy) are sometimes used to shatter stones; the fragments pass into the bowel and cause no further problems.

Drugs such as chenodeoxycholic acid or ursodeoxycholic acid can dissolve some stones if given over a period of months.... gallstones

n. (pl. calculi) 1. a stone: a hard pebble-like mass formed within the body, particularly in the gall bladder (see gallstone) or anywhere in the urinary tract (see cystolithiasis; nephrolithiasis; staghorn calculus). Calculi in the urinary tract are commonly composed of calcium oxalate and are usually visible on X-ray examination. Some of these stones cause pain if they are associated with obstruction and prevent urine flow in the ureter or kidney, or by direct irritation of the bladder. Stones passing down a duct (such as the ureter) cause severe colicky pain. Most stones pass spontaneously, but some need to be broken into smaller pieces, usually by extracorporeal *lithotripsy, and the remainder by endosurgical techniques (see litholapaxy) or rarely by open surgery. Calculi may also occur in the ducts of the salivary glands. 2. a calcified deposit that forms on the surface of a tooth that is covered with dental *plaque as a result of poor oral hygiene. Supragingival calculus forms above the *gingivae (gums), principally in relation to the openings of the salivary gland ducts. Subgingival calculus forms beneath the crest of the gingivae. Calculus hinders the cleaning of teeth and its presence contributes to *gingivitis and *periodontal disease. A link has been demonstrated between increased calculus levels and infective *endocarditis.... calculus

n. a hard mass composed of bile pigments, cholesterol, and calcium salts, in varying proportions, that can form in the gall bladder. The formation of gallstones (cholelithiasis) occurs when the physical characteristics of bile alter so that cholesterol is less soluble or there is an excess of bile pigments. Diminished contractility of the gall bladder may also be a contributory factor, leading to biliary stasis. Gallstones may exist for many years without causing symptoms. However, they may cause severe pain (see biliary colic) or they may pass into the common bile duct and cause obstructive *jaundice or *cholangitis. Gallstones are usually diagnosed by ultrasonography, but those containing calcium may be seen on a plain X-ray (opaque stones). Symptomatic cholelithiasis is usually treated by surgical removal of the gall bladder (see cholecystectomy). Nonsurgical treatments, such as gallstone-dissolving drugs or lithotripsy, have proved less successful and are not in widespread use.... gallstone

(minimal-access surgery) surgical intervention involving the least possible physical trauma to the patient, particularly surgery performed using an operating laparoscope or other endoscope (see laparoscopy) passed through tiny incisions; it is known popularly as keyhole surgery. Several types of abdominal surgery, including gall bladder removal (see cholecystectomy) and extracorporeal shock-wave *lithotripsy for stones in the urinary or bile drainage system, are commonly performed in this way. Such methods are usually more comfortable and allow the patient to resume normal activity much sooner than would be possible after more conventional procedures. See also interventional radiology.... minimally invasive surgery