Intravesical formalin for hemorrhagic cystitis: analysis of therapy

In an extensive search of the literature 235 cases of intractable hemorrhagic cystitis treated with intravesical formalin were identified. Effectiveness of therapy, rate of recurrence of hematuria, morbidity and mortality were analyzed with respect to concentration of formalin and to the etiology of hematuria. Increasing concentrations of formalin slightly improved effectiveness of therapy and reduced the rate of recurrence of hematuria. However, this often resulted in an increase in morbidity. When patients were categorized according to the etiology of intractable hematuria it was noted that lower concentrations of formalin were effective in controlling hematuria caused by either cyclophosphamide cystitis or unresectable carcinoma of the bladder. In contrast, higher formalin concentrations were required to control bleeding due to radiation cystitis.