Urinary stone disease and management

Urinary stone disease, symptoms, precautions and its management, read on to find out:

Urinary stone disease is presently a very common problem. The frequency of urinary stone in all individuals is measured at 3 percent and affects up to 12 percent of the population over their lifetime. Rates of urinary stone relapse approach 50 percent at 10 years and the highest incidence is in white males in the US. It has increased significantly in India over the last couple of years. Unless treated properly with adequate countermeasures to prevent further stones, this can be a continuous problem which can even lead to renal failure.

Formation of kidney stones

Kidney stones can form when substances in the urine—such as calcium, oxalate, phosphorus, uric acid etc, become highly concentrated. Stones are solutes that occur in quantities too large to remain dissolved in urine. The body makes use of food for repairing energy and tissue. After the body absorbs what it needs, waste byproducts are carried to the kidneys in the bloodstream and excreted as urine. At the urine secreting sites of the kidney, these substances are initially accumulated in the kidney as small crystals. The crystals grow and expand to form stones of various sizes when they are not washed off due to reduced water intake or due to other factors causing adhesion. Diet is one of the several factors that can promote or inhibit kidney stone formation. Certain foods may encourage stone formation in susceptible individuals, but scientists do not believe that consuming any particular food causes stones to form in people who are not susceptible. Other factors affecting the formation of a kidney stone include genetic traits, surroundings, body weight, and the intake of fluids.

Types of kidney stones

Four major types of kidney stones can be formed. The most common type of kidney stone is calcium stones and occurs in two main elements: calcium oxalate and calcium phosphate. Calcium oxalate stones are more common. The formation of calcium oxalate stone can be due to high calcium and high excretion of oxalate. Calcium phosphate stones are caused by a mixture of high urine calcium and alkaline urine, indicating that urine has a high pH. Uric acid stones form when the urine is habitually acidic.The formation of calcium oxalate stone can be due to high calcium and high excretion of oxalate. Calcium phosphate stones are caused by a mixture of high urine calcium and alkaline urine, indicating that urine has a high pH. Uric acid stones form when the urine is habitually acidic. Struvite stones result from kidney infections. The most common pathogen being Proteus mirabilis. Less common pathogens include Klebsiella, Enterobacter, or Pseudomonas.Removing infected stones from the urinary tract and staying free from infection can help stop more struvite stones. Cystine stones are due to a genetic disorder that causes cystine to spill through the kidneys and into the urine, forming crystals that tend to build up into stones. There are other less common stones, including xanthine and stones related to drugs.

Clinical symptoms of kidney stone

Renal stone is the classic presentation of intense, colicky flank pain that radiates to the groin or scrotum. As the stone goes into the ureter, pain may be localized to the abdomen. Renal and ureteral colic is often considered among the most severe pain experienced by patients. Lower abdominal pain, urinary urge, frequency, and dysuria are common as the stone enters the urinary bladder. Haematuria, Nausea, and vomiting can also be present. Urinary infection with fever can as a recurrent feature might be present.  Some large stones attached in the kidneys may not cause any of these symptoms and are incidentally diagnosed on diagnostic assessment.

Diagnostic tests for kidney stone

Blood tests to monitor inflammation, uric acid, and renal function, also a  basic X-ray KUB and abdomen ultrasound can be done. Simple CT KUB is the ideal choice for confirmatory investigation. You can see all sorts of stones, the actual size and location identified and the degree of kidney obstruction can be determined. Ultrasound may miss lower ureteric calculi and some stones are not visible on the x-ray. If a person is able to catch a kidney stone as it goes, it can be sent for evaluation to a laboratory. Blood and urine can also be assessed for abnormal levels of chemical substances such as calcium, oxalate and sodium to help decide what type of kidney stone a person may have had.

Prevention methods of kidney stone

A major step in avoiding kidney stones is recognizing what causes the stones to shape. This knowledge will help recommend improvements in the diet to avoid potential stones in the kidney. Restricting oxalate in the diet, for example, will help avoid calcium oxalate stones but does not do anything to avoid uric acid stones. More than one type of stone can be kept in check with some dietary recommendations. Particularly, drinking enough fluids helps avoid kidney stones of all kinds by maintaining urine diluted, and by rinsing away materials that might form stones. People can prevent kidney stones by trying to make fluid intake changes, and changes in sodium, animal protein, calcium, and oxalate intake, depending on the type of kidney stone. The best way to prevent most types of kidney stones is to drink enough fluids every day, we recommend drinking 2.5-3 liters of fluid per day. Individuals with cystine stones may need to get much more drink. While water is best, other fluids, including citrus drinks, can also help to prevent kidney stones. Persons with kidney stone should consume ample water and other fluids to produce at least 1.5 liters of urine a day. Citrus drinks such as lemonade and orange juice defend against kidney stones as they have citrate which prevents the growth of crystals into stones. The risk of kidney stones grows if the daily intake of sodium is increased. The prescribed US sodium dietary allowance (RDA) is 2,300 milligrams ( mg). Meats and other animal proteins, such as eggs and fish, contain purines that dissolve in the urine into uric acid. Foods that are particularly rich in purines are organ meats like the liver. People who produce uric acid stones should restrict their meat intake to 6 ounces per day. Animal protein also can increase the risk of calcium stones by increasing calcium excretion. Every urologist usually has a diet chart for stone prevention.

Medical management of kidney stone

This is normally only achievable in small stones, only around 6 mm in size. The ureter which transports urine from the kidney to the bladder is only 5-6 mm diameter in size. The stones move from the kidney to the ureter and get blocked. Medicines will attempt to wash the stones out. The medicines lubricate the ureter and facilitate the removal of stones. However, it is unlikely that a ureteral stone that has not passed within 1-2 months can pass spontaneously with further examination or treatment. Potassium magnesium citrate, soda bicarbonate, etc are only a few stone-dissolving medicines.

Surgical management of kidney stone

Ureteric stones - stones in the ureter up to 2 cm are usually treated by (URS). In this method, a small scope is inserted into the ureter through the natural orifice, and a laser splits the stone. The laser cuts the stone into a fine powder and it gets absolutely removed. A stent is placed for 3 weeks. It is a single day procedure under anesthesia. Stones exceeding 2 cm are generally removed with laparoscopy (keyhole) where the ureter is opened and the entire stone is discarded.

Kidney stones- Small stones above 6mm up to 1.5 cm can be broken with ESWL(shock wave) lithotripsy. In this method, the stone is centered under ultrasound guidance with a shockwave and broken in one to three sessions. It is done without anesthesia in an operating room. Each session takes approximately half an hour and the patient may go home the same day. The stone fragments pass down naturally via the ureter and are expelled in the urine. But, with this process, the stones clearance rate is less.

RIRS(The Latest in Kidney stone management) is a procedure in which a flexible ureteroscope is placed via the natural orifice into the kidney and with the help of a laser, Stones of any size up to 3 cm, whether multiple or single, maybe clearly broken. Total removal of the stone can be accomplished in one session.

PCNL – This is a treatment for big kidney stones in which a small 1 cm incision is made on the abdomen side by means of which devices are positioned, under x-ray guidance, to reach the kidney stone, the stone is totally broken and the remains are extracted by this surgical hole and we can achieve total removal of the stones.

3D Laparoscopy(keyhole) – This method is for very large and multiple stones involving the entire kidney. Here the kidney is bi-valved and open, and all the stones are completely removed. Then the 2 halves of the kidney are closed with sutures and the kidney again functions as a normal kidney.

Patients who get treated for kidney stones by whatever means have a 50% chance of recurrence of stones. Hence they need to be on long term medication for stone prevention and adequate and follow up with a urologist is required for a safe and healthy kidney!

Dr Datson George P

Consultant Urologist, Endourologist and Transplant surgeon 

VPS Lakeshore cochin