A Review of Hyperbaric Oxygen Therapy for Inflammatory Bowel Disease

Hyperbaric oxygen augments susceptibility to C. difficile infection by impairing gut microbiota ability to stimulate the HIF-1α-IL-22 axis in ILC3

Hyperbaric oxygen (HBO) therapy is a well-established method for improving tissue oxygenation and is typically used for the treatment of various inflammatory conditions, including infectious diseases. However, its effect on the intestinal mucosa, a microenvironment known to be physiologically hypoxic, remains unclear. Here, we demonstrated that daily treatment with hyperbaric oxygen affects gut microbiome composition, worsening antibiotic-induced dysbiosis. Accordingly, HBO-treated mice were more susceptible to Clostridioides difficile infection (CDI), an enteric pathogen highly associated with antibiotic-induced colitis. These observations were closely linked with a decline in the level of microbiota-derived short-chain fatty acids (SCFAs). Butyrate, a SCFA produced primarily by anaerobic microbial species, mitigated HBO-induced susceptibility to CDI and increased epithelial barrier integrity by improving group 3 innate lymphoid cell (ILC3) responses. Mice displaying tissue-specific deletion of HIF-1 in RORγt-positive cells exhibited no protective effect of butyrate during CDI. In contrast, the reinforcement of HIF-1 signaling in RORγt-positive cells through the conditional deletion of VHL mitigated disease outcome, even after HBO therapy. Taken together, we conclude that HBO induces intestinal dysbiosis and impairs the production of SCFAs affecting the HIF-1α-IL-22 axis in ILC3 and worsening the response of mice to subsequent C. difficile infection.

Persistent perineal sinus following proctocolectomy in the inflammatory bowel disease patient

Prolonged perineal wound healing following proctocolectomy in patients with inflammatory bowel disease (IBD) is a frustrating result for the medical team and patients who were hoping for improved quality of life. Prolonged healing, which lasts more than 6 months following proctocolectomy, is termed persistent perineal sinus (PPS) and typically necessitates further surgical management. Healing of the PPS is difficult due to the resulting "dead space" following proctocolectomy, necessitating the need to fill the void with viable tissue in an area with anatomic constraints. Here we provide a narrative review and comprehensively address the incidence, pathogenesis, and clinical and operative management of a PPS in patients with IBD following proctocolectomy. Operative methods discussed include surgical debridement, flap closure of the perineum, omental flap closure, and gracilis muscle transposition. It is necessary to further investigate and establish a gold standard of care for these patients.

Gracilis Muscle Interposition for the Treatment of Rectovaginal Fistula: A Systematic Review and Pooled Analysis

BACKGROUND

A rectovaginal fistula is a debilitating condition that often severely impacts quality of life. Despite many treatment options available, the best surgical treatment is far from being established, and many patients will undergo several procedures before fistula closure is achieved. Gracilis muscle interposition, which is the transposition of the gracilis muscle into the rectovaginal septum, is an option for complex and persistent fistulas, but literature on the subject is scarce, mainly consisting of small case series.

OBJECTIVE

This study aimed to assess the success rate of gracilis muscle interposition for the surgical treatment of rectovaginal fistula.

DATA SOURCES

MEDLINE, Embase, Cochrane Library, and Web of Science.

STUDY SELECTION

Studies comprising at least 5 patients who underwent gracilis muscle interposition for rectovaginal fistula were included. No date or language restrictions was applied.

INTERVENTION

Gracilis muscle interposition.

MAIN OUTCOME MEASURES

The primary outcome is the fistula closure rate (%). Other domains analyzed are stoma closure rate, postoperative complications, quality of life, fecal continence, and sexual function.

RESULTS

Twenty studies were included for a total of 384 patients. The pooled fistula closure rate for gracilis muscle interposition was 64% (95% CI, 53%-74%; range, 33%-100%). Risk factors for failure were smoking, underlying Crohn's disease, and more than 2 previous repairs, whereas stoma formation was associated with improved outcomes. Postoperative complications ranged from 0% to 37%, mostly related to surgical site occurrences at the harvest site and perineal area. No deaths occurred. Gracilis muscle interposition improved quality of life and fecal continence, but impairment of sexual function was common.

LIMITATIONS

Most of the included studies were small case series.

CONCLUSIONS

Gracilis muscle interposition is a safe and moderately effective treatment that could be taken into consideration as second- or third-line therapy for recurrent rectovaginal fistula.

REGISTRATION NO

CRD42022319621.