Q. Last week, I was confined in a hospital because I experienced severe left sided abdominal pain. After X-rays and ultrasound examinations,  my doctor told me that I have kidney stones and a small one is in the ureter. I was given strong pain relievers, which partially relieved the pain. After a day in the hospital, the pain subsided and my doctor said I probably passed the stone out with my urine. What should be done about the stones that I have in my kidneys?   

--Rabyn R., General Santos City

A. Urinary stones are hard, often tiny, objects that are present anywhere in the urinary tract—kidneys, ureters, urinary bladder and urethra. Most (85 percent) are made up of calcium (oxalates or phosphates) and the rest consist of struvite, uric acid and cystine. They are more common in men than in women (at a ratio of 4:1). Next to infection and prostatic diseases (in men), urinary stone disease is the most frequent disorder that affects the urinary tract.

Normally, urine contains chemicals that prevent or inhibit the formation of stones, but in some people these chemicals are lacking or not working, so stones form.  Urinary stones generally form in the kidneys where they often do not manifest any symptom. It is only when a stone or a fragment thereof drops from the kidney to the ureter—the tiny tube that conveys urine from the kidney to the urinary bladder—that symptoms manifest.

The usual initial symptom of a ureteral stone is sudden excruciating and episodic pain that is felt on the flank, but which may radiate over the abdomen and the testis (in men) or labium (in women). The pain is often accompanied by nausea and vomiting and sometimes by urgency and frequency of urination. Occasionally, especially if there is an accompanying infection, fever is also present. In general, the urine of patients with a ureteral stone contains some amount of blood, but rarely is the blood sufficient in amount to be appreciated by the naked eye.

Most urinary stones can be detected by either X-ray or ultrasound examination. Other tests that are sometimes employed to determine the proper treatment include computerized tomography (CT) scan and intravenous pyelography (IVP).

In managing urinary stones, surgery is usually not necessary. In fact, as in your case, most stones that find their way into the ureter pass-out with urine in a few hours to several days. Hence, often, the only treatment necessary is a strong pain reliever that will ease the patient’s miseries while waiting for the stone to spontaneously pass out. Stones in the kidneys, especially if asymptomatic, are likewise simply observed over a period of time.

More invasive treatment of a urinary stone is warranted only if the stone does not pass out after a reasonable period of time (say 6 weeks) and causes constant pain; is very large to pass on its own or is permanently lodged; has grown as seen on follow up X-ray; or, it blocks the flow of urine—which can lead to infection and/or kidney damage.

A ureteral stone is removed by either uteroscopic stone extraction or extracorporeal shock wave lithotripsy (ESWL). Uteroscopic stone extraction involves the passage of a small tube with a camera or fiber optic system through the urethra into the ureter and extraction of the stone under direct vision. ESWL, on the other hand, which is especially effective in handling relatively large stones not only in the ureter but also in the kidneys and other parts of the urinary tract, involves the external application of shock waves to break down the stone into smaller pieces that can then pass out easily with the urine.

Another procedure that is sometimes employed in removing urinary stones is percutaneous nephrolithotomy, where the surgeon makes a tiny incision in the back and creates a tunnel directly into the kidney and locates and removes the stone by using an instrument called a nephroscope. 

Stones often recur. Recurrence can be partly prevented by drinking enough water (at least 10 glasses per day) and by shifting to a low-salt and low-protein diet.      

(E-mail inquiries on health matters to: medical_notes@yahoo.com or wellbeing@mb.com.ph.)