Hyperbaric oxygen therapy for Crohn’s disease complications: What do we know?

Dear editor

We read with great interest the article by Lansdorp et al. ¹ The authors report a high rate of metastatic Crohn’s disease (CD) in patients with ongoing wound-healing problems after proctectomy after hyperbaric oxygen therapy (HBO).

Adjunctive HBO in medically refractory CD complications is not a novel therapeutic strategy, and has been used in therapeutic algorithms for more than a decade. ² Even with optimal medical therapy strategies, patients may experience disease progression and perianal complications. These immune and non-immune complications may present as open wounds such as metastatic CD and perianal fistulizing Crohn’s disease (pCD). The latter represents a difficult phenotype of the disease that can require intensive medical therapy, wound care, surgical intervention ³ and sometimes an adjunctive HBO. ⁴

HBO is an interesting therapeutic approach, although its mechanism of action is not totally clear. Previous studies demonstrated the effectiveness of HBO in a model of experimental colitis by decreasing tissue damage. Expression levels of major inflammatory mediators in the damaged tissue such as pro-inflammatory cytokines (tumour necrosis factor-alpha and interleukin-1 beta), as well as neutrophil infiltration, were found to be down-regulated by HBO, suggesting that they were involved in the therapeutic effects in experimental acute colitis. ⁵

Although it is unclear how many sessions are optimal for these patients, one previous study showed a median of around 20 sessions (ranging up to 80 sessions), with no complications found during the procedure. The results presented by Lansdorp et al. ¹ are encouraging, since these three patients, who were medically refractory, obtained high healing rates. However, the small number of patients, the short-term follow-up and the lack of a control group limit their conclusions. A prospective controlled study could solve this problem. However, it would be ethically questionable to create a control group and deny the possibility of treatment in patients with an aggressive condition and limited therapeutic options. Landsdorp et al. ⁶ proposed a non-randomized controlled trial to investigate the feasibility and therapeutic effect of HBO on pCD. Since metastatic CD might not be as rare as previously thought, it would be interesting to perform a multicentric protocol to investigate the feasibility and therapeutic effect of HBO on metastatic CD.