Endoscopic fulguration of the trigone, also called endoscopic diathermy, has been around for a long time to treat chronic painful bladder lesions, as sometimes seen in women suffering from interstitial cystitis. Although known from pelvic floor surgeons, there is a dearth of reports on the use of this technique in the management of recurrent urinary tract infections (RUTIS) in women. 

After a thorough evaluation of these patients to exclude upper and lower urinary tract pathologies, including pelvic examination, renal ultrasound, voiding cystogram, cystoscopy, and basic voiding parameters (flow and postvoid residual), has been completed and returned negative, in those with antibiotic-refractory RUTIs who have chronic trigonitis recognized on office-based cystoscopy, we have proceeded with electrofulguration of the trigonitis area [1]. Additional work from our group on bladder biopsies of these areas before fulguration has been reported and showed resident bacteria deep in the tissues, suggesting that the mechanism for recurrence is internal and not via a urethral ascending mechanism in these women [2]. 
This movie describes our endoscopic fulguration technique in a representative patient.

At the start of the procedure, the location of each ureteric orifice is identified. Using a 17.5 Fr Wolff female urethroscope and a fine tip bugbee electrode on a low setting of 20 for surface cauterization, the fulguration starts medial to the ureteric orifice, along the inter-ureteric ridge, first on the left and then on the right to join the other side. The area just above the bladder neck area is cauterized as well from right to left.  The area inside these blanched lines can then be cauterized without fear of injuring the ureters or the urethra. The final survey of the cauterized area indicates no active bleeding and the elimination of all visible chronic lesions.

In this 69 year old woman with a 12 year history of recurrent urinary tract infections, lesions of cystitis cystica, pus pockets and tiny stones or encrustations are easily recognized when surveying the whole trigone area. In urine, the process of healing is very slow. Here at 6 months later, the whole area has finally healed and the inflamed trigone has been replaced by a thin, pale, lining with no new inflammatory lesions seen. 

Our experience with this endoscopic fulguation procedure spans nearly two decades. One recent series reported on 95 patients [1]. Another publication on the biopsy findings of these areas of chronic cystitis used a FISH technology to identify resident bacteria in these inflamed areas [2]. A recent series on 40 women with early stages of inflammation just confined to the trigone (stage1) and long-term follow-up indicates a very good outcome in these women [3]. Such findings may encourage women prone to relapsing infections and high user of ineffective antibiotic therapies to consider this short outpatient intervention with very minimal morbidity.

Although we only presented in this movie our experience with fulguration of trigonitis alone in the management of antibiotic-recalcitrant RUTIs, the same procedure can be applied when a larger burden of cystitis lesions involving additional areas of the bladder wall, including dome, anterior bladder, and lateral bladder walls, are present.

Crivelli and Zimmern, IJU 2019.
DeNisco et al. JMB 2019.
Stevens et al. JUTI, 2021