Urate kidney stones are formed from uric acid. More often, the cause of their appearance is an increase in the acidity of urine due to the consumption of animal foods and various diseases (including gout and obesity). Today, urate stones occur in 10-15% of cases of urolithiasis, and in the future their prevalence may increase. How to effectively relieve a patient from this disease? Let’s talk to the experts.
It was previously assumed that uric acid stones have a homogeneous structure. However, after researchers from Sechenov University, Skolkovo Institute of Science and Technology and the Soil Institute studied them in detail using X-ray microtomography and electron microscopy, it turned out that such stones have a layered structure with heterogeneous crystals. In one stone there can be both compact layers of uric acid and loose, porous ones. In addition, it turned out that one stone always contains crystals of different morphologies in the form of elongated rectangles or sharp needles. These features affect the effectiveness of both pharmacological treatment and stone destruction using ultrasound.
“Uric acid stones exhibit calcium oxalate inclusions in the form of cores and layers, as well as porosity patterns consisting of loose and more compact uric acid anhydride, uricite,” said aif.ru junior researcher at the Institute of Regenerative Medicine of Sechenov University, specialist in the field of microtomography Sergei Tkachev.
The identified features explain why not all urate stones are equally susceptible to destruction during lithotripsy.
“Our team has found that the cores and layers of calcium oxalate monohydrate and uric acid directly affect the effectiveness of lithotripsy, since they are less susceptible to destruction, as was shown in an experiment with a new Russian thulium laser,” shared the results of the experiment urologist, associate professor at the Institute of Urology and Human Reproductive Health Stanislav Ali. – In the future, we plan to continue experiments to find out how the frequency and duration of laser pulses, as well as changes in laser power, can affect the speed of the operation and the size of the fragments: the smaller the fragments, the lower the risk of their movement in the kidney and the higher the chance of their complete completion. extraction, which is important to reduce the risk of re-growth of stones and, as a consequence, relapse and repeat operations.”
Presumably, the structural features of the stone may also affect the results of pharmacological therapy – urine, which contains a drug to dissolve the stone, should penetrate better into porous stones. But scientists have yet to explore the details of this process.
Uneven growth of stones can be associated with the patient’s diet and lifestyle: the composition of urine is affected by diet, amount of fluid consumed, weather conditions, physical activity, taking certain medications, and much more. In addition, urine flows unevenly to different parts of the kidney, so the concentration of uric acid may fluctuate and, as a result, the structure of the stones will be heterogeneous.
Researchers expect that new data will improve methods of treatment and prevention of urolithiasis.
Source: aif.ru