Dissolution of uric acid stones in the ureter

Introduction. Uric acid stones (UA), consisting of uric acid/uric acid dihydrate, occur in 6.1-15.1% of all cases of urolithiasis in industrialized countries. At the same time, the frequency of these stones is directly dependent on age. Thus, the incidence of UA reaches 40% in men over 80 years of age and 27.3% in women over 90 years of age. UA are the only stones that are amenable to dissolution therapy with the use of citrate salts that alkalinize urine pH. A number of authors and European Association of Urology guidelines consider stone dissolution as a first-line therapy in the treatment of patients with UA, both as monotherapy and in combination with surgical procedures. Materials and methods. The results of conservative treatment of 86 patients aged 28 to 78 years with radiolucent ureteral stones ranging in size from 3 to 25 mm and a density of 133 to 728 HU, who underwent 89 courses of stone dissolution therapy from 2011 to 2018, are presented in the article. They had no obstruction or were prestented. There were 52 men (n=55 courses) and 34 women (n=34 courses). Results. In 78 out of 89 clinical cases (87.6%), stone-free status was obtained within 14 to 181 days. Most often the duration of therapy was 30 days. In 11 (12.4%) cases the treatment was considered ineffective. However, only in 4 (4.5%) patients the stone size did not change, while in 7 (7.9%) cases it decreased. The results of the study suggest the high efficiency of citrate therapy in patients with ureteral stones in case of unobstructed urine outflow (including those with stents), which is comparable to surgical treatment.

uric acid stones, urate stones, ureteral stone, citrate therapy, stone dissolution