Abstract
We report a 4-year-old boy with acute obstruction of hydronephrosis due to incarceration with clotted blood in the ureter. The patient had undergone a right pyelo-ureteroplasty for congenital hydronephrosis at 4 month after birth. Just before the present admission, he had fallen down some stairs, causing a blow to the right abdomen. Gross hematuria was found at a few hours later. On admission, blood examination data showed no anemia, and blood chemistry parameters were within the normal ranges. Abdominal ultrasound showed only mild hydronephrosis in the right kidney. We started the conservative therapy with a drip infusion with hemostatic agents containing 1000mg/day tranexamic acid under a tentative diagnosis of renal injury (Ia). On day 3, gross hematuria disappeared and drip infusion therapy was withdrawn. However, a few hours later the patient complained of severe abdominal pain and vomited frequently. At that time, abdominal ultrasound and intravenous pyelograph showed severe right pelvic dilatation. The patient then voided a blood clot in the urine, and the abdominal pain and frequent vomiting promptly disappeared.
The cause of intraureteral coagulation in this case would have been urinary stagnation due to hydronephrosis and excessive antifibrinolytic activity of tranexamic acid. Hydration and administration of hemostatic agents at an appropriate dose are important for prevention of clot formation in cases like the present one.
