title: Intravesical formalin for hemorrhagic cystitis: A contemporary cohort.
abstract: BACKGROUND
  Hemorrhagic cystitis presents a difficult clinical challenge, yet data regarding treatment options is sparse. Here, we sought to evaluate outcomes of a contemporary cohort of patients treated with intravesical formalin for hemorrhagic cystitis.
  
  
  METHODS
  We identified a retrospective cohort of eight patients managed with formalin for hemorrhagic cystitis from 2000-2014. All patients failed prior measures, including bladder irrigation, clot evacuation, and other intravesical agents. Treatment success was defined as hematuria resolution during the given hospitalization without use of additional invasive therapies. We also evaluated treatment complications and additional treatments following hospital dismissal.
  
  
  RESULTS
  Etiology of cystitis was radiation for malignancy in all cases. The formalin concentration ranged from 1-4%, with escalation used in treatment failures. Five patients (62.5%) received a single dose of 1% formalin, two patients received two doses, and one patient received three doses. Notably, intraoperative cystography identified vesicoureteral reflux (VUR) in 50.0% of patients. Six patients (75.0%) achieved treatment success, with a median time to resolution of four days (range 1-17 days). Of those refractory to formalin, one was managed with indwelling nephrostomy tubes and one underwent cystectomy. Median followup was eight months. Of the responders, two eventually required cystectomy, one for recurrent hematuria and one for recalcitrant bladder neck contracture and bladder dysfunction. The remaining four patients (50%) required no additional therapy.
  
  
  CONCLUSIONS
  Formalin remains an important tool for treating refractory hemorrhagic cystitis, with roughly 75.0% of patients requiring no additional therapy prior to hospital discharge. Notably, there is a risk of bladder dysfunction following formalin.
authors.affiliation: Department of Urology, Mayo Clinic, Rochester, MN, United States.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Ziegelmann
authors.affiliation: Department of Urology, Mayo Clinic, Rochester, MN, United States.
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Boorjian
authors.affiliation: Department of Urology, Mayo Clinic, Rochester, MN, United States.
authors.forename: Daniel D
authors.initials: DD
authors.lastname: Joyce
authors.affiliation: Department of Urology, Mayo Clinic, Rochester, MN, United States.
authors.forename: Brian D
authors.initials: BD
authors.lastname: Montgomery
authors.affiliation: Department of Urology, Mayo Clinic, Rochester, MN, United States.
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Linder