Summary— Two series of patients with histologically proven interstitial cystitis that was unresponsive to hydrostatic bladder distension and intravesical chemotherapy with dimethyl sulfoxide have been studied. In the first series 24 patients were treated by subtotal cystectomy and substitution cystoplasty without further consideration; 8 of these 24 patients had persistent frequency due to active disease in the remaining trigone and/or urethra and in 2 cases this was severe.
Because of this experience the second group of patients had routine biopsy of the trigone and assessment of urethral sensation as part of the initial assessment. In those in whom the trigone was unaffected, treatment was unchanged. If the trigone was affected, total cystourethrectomy was performed with substitution cystourethroplasty unless the patient chose or was advised to avoid surgery altogether or to have a simpler option such as conduit or continent urinary diversion.
Trigonal biopsies should be part of the routine assessment of all patients being considered for surgery, since residual active disease is a major cause of dissatisfaction after subtotal cystectomy and substitution cystoplasty.