Gastrointestinal: Leveraging intestinal ultrasound to guide endoscopic closure of the internal opening of a vesico-sigmoid fistula in ileo-colonic Crohn's disease

Abstract

The intestinal ultrasound (IUS) figure indicates a vesico-sigmoid fistula between bladder and sigmoid loop (Fig. 1a,b), a complication associated with Crohn's disease (CD). To confirm our findings, we did a colonoscopy and could identify the internal opening of the fistula (F) in the sigmoid colon (Fig. 2a). We put three hemoclips (C) to close the internal opening of the fistula as identified in the IUS and confirmed by sigmoidoscopy (Fig. 2b). The patient was started on combined immunosuppression with adalimumab and azathioprine. On 6-month follow-up, there were no symptoms of recurrent urinary tract infections. The patient is currently in clinical remission. The CRP levels normalized to 2 mg/L, indicating a positive response to the treatment. The surveillance sigmoidoscopy for the patient is planned at 12 months post-intervention, alongside a repeat IUS to monitor for any recurrence or new complications.

The role of IUS in guiding medical therapy in inflammatory bowel disease (IBD) is widely recognized.¹ However, its application in guiding endoscopic therapy for IBD has not been extensively explored in existing literature. Our experience underscores the high accuracy of IUS in identifying CD-related complications, such as fistulae. The precise localization of the vesico-sigmoid fistula facilitated by IUS played a pivotal role in guiding endoscopic closure of the internal opening, thereby obviating the need for invasive investigations like cystoscopy or conventional cystograms. We highlighted the potential utility of through-the-scope (TTS) clips for temporary closure of bowel-to-hollow-organ fistulae while awaiting response to advanced therapy. Over-the-scope clips (OTSC) are not recommended for such fistula due to risk of fistula worsening due to thin septum in between two openings.^{2, 3} This case underscores the novel application of IUS in the management of complex IBD cases, further expanding its role in the armamentarium of therapeutic options.