154 Hyperbaric Oxygen Therapy as Salvage for Crohn's-Like Disease of the Pouch in a Patient With PSC-IBD

Background: Patients with PSC-IBD who undergo ileal pouch-anal anastomosis (IPAA) are at increased risk of developing complicated chronic pouchitis. This unique phenotype can be refractory to standard therapies as well as advanced therapies including biologics and small molecule therapy, leaving patients with limited treatment options and high risk of pouch failure. The following is a case demonstrating the successful use of hyperbaric oxygen therapy (HBOT) as salvage treatment for a 26-year-old female with PSC-IBD and refractory Crohn’s-like disease of the pouch (CDP). Methods: This is a case report detailing the clinical course of a 26-year-old female with PSC-IBD who developed medically refractory CDP with a perianal fistula after a total colectomy with IPAA. The patient's extensive past medical history of failed medical therapies was reviewed. Endoscopic findings were documented using the Pouchitis Disease Activity Index (PDAI) endoscopic score. Results: The patient, a 26-year-old female with PSC-IBD s/P multistage IPAA for medically refractory UC in 2019 after failing to respond to numerous advanced medical therapies (adalimumab, infliximab and azathioprine, ustekinumab and tofacitinib) after her initial diagnosis of UC in 2017. She subsequently developed chronic pouchitis with CDP phenotype based on perianal fistula and pre-pouch ileal inflammation on endoscopy. Subsequent medical therapies that were tried and failed include: chronic ciprofloxacin and metronidazole, tofacitinib, infliximab, risankizumab, vedolizumab. Upadacitinib was initiated in May 2024 and she was treated with an 8-week prednisone taper in October 2024 due to severe symptoms including nocturnal diarrhea, bleeding and abdominal cramping. Pouchoscopy performed January 2025 demonstrated PDAI endoscopic score of 6 with significant cuffitis, pre-pouch ileitis and an actively draining perianal fistula. The patient opted for hyperbaric oxygen therapy (HBOT) as salvage therapy. She completed 40 sessions at 2.4 ATA for 90 minutes in a hard-shell hyperbaric chamber from April 7 through June 20, 2025. This was paid out of pocket ($10,800) due to lack of insurance coverage. After 10 sessions the patient reported reduction in nocturnal symptoms as well as abdominal pain and stool frequency. A repeat pouchoscopy in August 2025 showed a PDAI endoscopic score of 1, with aphthae limited to the pouch body anastomosis line. There was complete resolution of cuffitis, pre-pouch ileitis and her perianal fistula was no longer draining. The patient also reported significant clinical improvement, with no nocturnal symptoms and stool frequency limited to 7 to 10 bowel movements a day with usage of antidiarrheals which represented significant improvement in her QOL and daily function. Conclusions: This case provides compelling evidence for the efficacy of HBOT as a salvage therapy for patients with medically refractory Crohn's disease of the pouch and highlights its potential as an important therapeutic option for patients with limited alternatives. Further research is warranted to explore HBOT's mechanism of action and its broader application in IBD. Further evidence demonstrating effective use of HBOT in inflammatory pouch disorders may improve insurance coverage and therefore increase access to this treatment modality for patients.