Hyperbaric oxygen therapy stimulates colonic stem cells and induces mucosal healing in patients with refractory ulcerative colitis: a prospective case series

Efficacy and Safety of Hyperbaric Oxygen Therapy in Fistulizing Crohn's Disease: A Systematic Review and Meta-analysis

BACKGROUND

Hyperbaric oxygen therapy (HBOT) delivers 100% oxygen in a pressurized chamber, increasing tissue oxygen levels and regulating inflammatory pathways. Mounting evidence suggests that HBOT may be effective for inflammatory bowel disease. Our systematic review and meta-analysis aimed to quantify the efficacy and safety of HBOT in fistulizing Crohn's disease (CD).

METHODS

A systematic review was conducted using the EMBASE, Web of Science, Pubmed, and Cochrane Library databases according to the "Preferred Reporting Items for Systematic Reviews and Meta-analyses" criteria. Study bias was assessed using the Cochrane Handbook guidelines.

RESULTS

Sixteen studies with 164 patients were included in the analysis. For all fistula subtypes, the pooled overall clinical response was 87% (95% CI: 0.70-0.95, I2 = 0) and the pooled clinical remission was 59% (95% CI: 0.35-0.80, I2 = 0). The overall clinical response was 89%, 84%, and 29% for perianal, enterocutaneous, and rectovaginal fistulas, respectively. On meta-regression, hours in the chamber and the number of HBOT sessions were not found to correlate with clinical response. The pooled number of adverse events was low at 51.7 per 10,000 HBOT sessions for all fistula types (95% CI: 16.8-159.3, I2 = 0). The risk of bias was observed across all studies.

CONCLUSION

HBOT is a safe and potentially effective treatment option for fistulizing CD. Randomized control trials are needed to substantiate the benefit of HBOT in fistulizing CD.

Role of hyperbaric oxygen therapy in patients with inflammatory bowel disease

PURPOSE OF REVIEW

Hypoxia is a known contributor to inflammation in inflammatory bowel diseases (IBD), and a growing interest has emerged in pharmacologically targeting hypoxia response pathways to treat IBD. The most basic form of treatment for hypoxia is delivering higher amounts of oxygen to the intestinal mucosa. In this review, we summarize the evidence in support of hyperbaric oxygen therapy (HBOT), a mechanism to deliver high amounts of oxygen to tissue, for treating IBD.

RECENT FINDINGS

Two phase 2 clinical trials in hospitalized ulcerative colitis patients suffering from moderate-to-severe flares have demonstrated that HBOT improves responsiveness to steroids and avoidance of rescue medical and surgical therapy. Outpatient cohort studies in perianal fistulizing Crohn's disease and fistulizing complications of the pouch have demonstrated improved healing, particularly for complex fistulae. Several systematic reviews have now been completed, and HBOT has been observed to be well tolerated with low rates of adverse events.

SUMMARY

HBOT may be considered as an adjunctive treatment for hospitalized ulcerative colitis flares and Crohn's disease-related fistulae. Higher quality trials are needed to confirm efficacy.

Addition of hyperbaric oxygen therapy versus usual care alone for inflammatory bowel disease: A systematic review and meta-analysis

Objective

Inflammatory bowel disease (IBD) is a chronic idiopathic inflammatory disease that includes ulcerative colitis (UC) and Crohn's disease (CD). Hyperbaric oxygen therapy (HBOT) involves breathing pure oxygen in a pressurized environment. Existing literature suggests that HBOT may be an effective therapy for IBD, but a quantitative analysis is lacking. This study aims to estimate the adjunctive role of HBOT in treating IBD and lowering its recurrence rate.

Design

Systematic review and meta-analysis.

Methods

The Cochrane Library, EMBASE, PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), China Science and Technology Journal Database (VIP), and Wanfang databases were systematically searched by two reviewers independently. Meta-analyses were performed using Review Manager (RevMan, version 5.3). A random-effects model was applied due to the heterogeneity between studies.

Results

Twenty-nine out of the initially identified 606 articles were covered in this review, with a total of 2151 patients (2071 for UC and 80 for CD). No randomized data of HBOT for CD were included. Among UC patients, usual care plus HBOT were more likely to achieve a clinical response than usual care alone (risk ratio [RR], 1.24; 95% confidence interval (CI), 1.17 to 1.31; P < 0.001). Subgroup analysis showed that the number of HBOT sessions had no statistically significant effect on overall efficacy (P > 0.05). The pooled data showed a lower recurrence rate in the usual care plus HBOT group (RR, 0.35; 95% CI, 0.24 to 0.53; P < 0.001). The standardized mean difference in the serum tumor necrosis factor level between HBOT and non-HBOT groups was -2.13 (95% CI, -3.09 to -1.18; P < 0.001). No severe adverse events of HBOT were observed.

Conclusions

HBOT might be an effective and safe adjunctive treatment for IBD. Further studies are required to investigate the optimal protocol of HBOT in IBD treatment.

Hyperbaric oxygen therapy for healthy aging: From mechanisms to therapeutics

Hyperbaric oxygen therapy (HBOT), a technique through which 100% oxygen is provided at a pressure higher than 1 atm absolute (ATA), has become a well-established treatment modality for multiple conditions. The noninvasive nature, favorable safety profile, and common clinical application of HBOT make it a competitive candidate for several new indications, one of them being aging and age-related diseases. In fact, despite the conventional wisdom that excessive oxygen accelerates aging, appropriate HBOT protocols without exceeding the toxicity threshold have shown great promise in therapies against aging. For one thing, an extensive body of basic research has expanded our mechanistic understanding of HBOT. Interestingly, the therapeutic targets of HBOT overlap considerably with those of aging and age-related diseases. For another, pre-clinical and small-scale clinical investigations have provided validated information on the efficacy of HBOT against aging from various aspects. However, a generally applicable protocol for HBOT to be utilized in therapies against aging needs to be defined as a subsequent step. It is high time to look back and summarize the recent advances concerning biological mechanisms and therapeutic implications of HBOT in promoting healthy aging and shed light on prospective directions. Here we provide the first comprehensive overview of HBOT in the field of aging and geriatric research, which allows the scientific community to be aware of the emerging tendency and move beyond conventional wisdom to scientific findings of translational value.

The Effectiveness and Safety of Hyperbaric Oxygen Therapy in Various Phenotypes of Inflammatory Bowel Disease: Systematic Review With Meta-analysis

BACKGROUND

Accumulating evidence suggests that hyperbaric oxygen therapy (HBOT) may be effective for inflammatory bowel disease (IBD). Our systematic review aimed to quantify the effectiveness and safety of HBOT in various IBD phenotypes.

METHODS

We performed a proportional meta-analysis. Multiple databases were systematically searched from inception through November 2020 without language restriction. We included studies that reported effectiveness and/or safety of HBOT in IBD. Weighted summary estimates with 95% confidence intervals (Cis) were calculated for clinical outcomes for each IBD phenotype using random-effects models. Study quality was assessed using the Cochrane evaluation handbook and National Institute of Health criteria.

RESULTS

Nineteen studies with 809 patients total were eligible: 3 randomized controlled trials and 16 case series. Rates of clinical remission included 87% (95% CI, 10-100) for ulcerative colitis (n = 42), 88% (95% CI, 46-98) for luminal Crohn's disease (CD, n = 8), 60% (95% CI, 40-76) for perianal CD (n = 102), 31% (95% CI, 16-50) for pouch disorders (n = 60), 92% (95% CI, 38-100) for pyoderma gangrenosum (n = 5), and 65% (95% CI, 10-97) for perianal sinus/metastatic CD (n = 7). Of the 12 studies that reported on safety, 15% of patients (n = 30) had minor adverse events. Study quality was low in the majority of studies due to an absence of comparator arms, inadequate description of concomitant interventions, and/or lack of objective outcomes.

CONCLUSIONS

Limited high-quality evidence suggests that HBOT is safe and associated with substantial rates of clinical remission for multiple IBD phenotypes. Well-designed randomized controlled trials are warranted to confirm the benefit of HBOT in IBD.

Hyperbaric Oxygen Therapy in Systemic Inflammatory Response Syndrome

(1) Background: Systemic inflammatory response syndrome (SIRS) can occur due to a large number of traumatic or non-traumatic diseases. Hyperbaric oxygen therapy (HBOT) may be used as a main or adjuvant treatment for inflammation, leading to the main aim of this study, which was to verify the applicability of HBOT as a safe and tolerable tool in SIRS-positive dogs. (2) Methods: This prospective cohort study included 49 dogs who showed two or more parameters of SIRS, divided into the Traumatic Study Group (n = 32) and the Non-Traumatic Study Group (n = 17). All dogs were submitted to HBOT for 60–90 min sessions, with 2.4–2.8 ATA. (3) Results: This study revealed that 73.5% (36/49) of dogs showed improvement, and the minimum number of HBOT sessions was two, with a mean of 12.73. The number of days between diagnosis and the beginning of HBOT showed statistical significance (p = 0.031) relative to the clinical outcome. No dogs showed any major side effects. (4) Conclusions: We concluded that HBOT may be safe and tolerable for SIRS-positive dogs, and that it should be applied as early as possible.

Hyperbaric oxygen therapy in inflammatory bowel disease: a systematic review and meta-analysis

BACKGROUND

Translational data suggest a potential role of hyperbaric oxygen therapy (HBOT) in a subset of patients with inflammatory bowel disease (IBD). We performed a systematic review and meta-analysis for the efficacy and safety of HBOT in IBD.

METHODS

We searched Pubmed, Embase and CENTRAL to identify studies reporting the efficacy of HBOT in ulcerative colitis or Crohn's disease. We pooled the response rates for HBOT in ulcerative colitis and Crohn's disease separately.

RESULTS

A total 18 studies were included in the systematic review and 16 in the analysis. The overall response rate of HBOT in ulcerative colitis was 83.24% (95% confidence interval: 61.90-93.82), while the response in Crohn's disease was 81.89 (76.72-86.11). The results of randomized trials for HBOT as adjuvant therapy in ulcerative colitis were conflicting. The complete healing of fistula in fistulizing Crohn's disease was noted 47.64% (22.05-74.54), while partial healing was noted in 34.29% (17.33-56.50%). Most of the adverse events were minor.

CONCLUSION

Observational studies suggest benefit of use of HBOT in ulcerative colitis flares and Crohn's disease. However, adequately powered randomized trials are needed to draw a definite conclusion.

Hyperbaric Oxygen Therapy in Chronic Inflammatory Conditions of the Pouch

BACKGROUND

Pouchitis can be a chronic complication of ileal pouch-anal anastomosis. We aimed to determine the efficacy and safety of hyperbaric oxygen therapy (HBOT) for chronic antibiotic-refractory pouchitis (CARP) and other inflammatory conditions of the pouch.

METHODS

This was a retrospective case series of adults with inflammatory bowel disease (IBD) who underwent ileal pouch-anal anastomosis and then developed CARP and received HBOT between January 2015 and October 2019. A modified Pouchitis Disease Activity Index (mPDAI) score was used to quantify subjective symptoms (0-6) and endoscopic findings (0-6) before and after HBOT.

RESULTS

A total of 46 patients were included, with 23 (50.0%) being males with a mean age of 43.6 ± 12.9 years. The median number of HBOT sessions was 30 (range 10-60). There was a significant reduction in the mean mPDAI symptom subscore from 3.19 to 1.91 after HBOT (P < 0.05). The pre- and post-HBOT mean mPDAI endoscopy subscores for the afferent limb were 2.31 ± 1.84 and 0.85 ± 1.28 (P = 0.006); for the pouch body, 2.34 ± 1.37 and 1.29 ± 1.38 (P < 0.001); and for the cuff, 1.93 ± 1.11 and 0.63 ± 1.12 (P < 0.001), respectively. Transient side effects included ear barotrauma in 5 patients (10.9%) and hyperbaric myopic vision changes in 5 patients (10.9%).

CONCLUSIONS

Despite minor adverse events, HBOT was well tolerated in patients with CARP and significantly improved symptoms and endoscopic parameters.

The role of hyperbaric oxygen therapy in inflammatory bowel disease: a narrative review

Inflammatory bowel disease is a group of chronic recurrent diseases in the digestive tract, including ulcerative colitis and Crohn's disease. Over the past few decades, the treatment of IBD has made great progress but there is still a lot of room for improvement. Hyperbaric oxygen therapy (HBOT) was defined as the therapeutic effect of inhaling 100% oxygen higher than one atmosphere and reported to be used in stroke, decompression sickness and wound healing. Since several authors reported the role of HBOT as an adjunct to conventional medical treatment in patients with refractory IBD, the relevant research has shown an increasing trend in recent years. Clinical and experimental studies have revealed that HBOT may exert its therapeutic effect by inhibiting inflammation and strengthening the antioxidant system, promoting the differentiation of colonic stem cells and recruiting cells involved in repair. The purpose of this review is to summarize the past clinical and experimental studies and to understand the impact of HBOT in the treatment of IBD more deeply. In addition, we also hope to provide some ideas for future clinical and research work.

Modern surgical strategies for perianal Crohn's disease

One of the most challenging phenotypes of Crohn’s disease is perianal fistulizing disease (PFCD). It occurs in up to 50% of the patients who also have symptoms in other parts of the gastrointestinal tract, and in 5% of the cases it occurs as the first manifestation. It is associated with severe symptoms, such as pain, fecal incontinence, and a significant reduction in quality of life. The presence of perianal disease in conjunction with Crohn’s disease portends a significantly worse disease course. These patients require close monitoring to identify those at risk of worsening disease, suboptimal biological drug levels, and signs of developing neoplasm. The last 2 decades have seen significant advancements in the management of PFCD. More recently, newer biologics, cell-based therapies, and novel surgical techniques have been introduced in the hope of improved outcomes. However, in refractory cases, many patients face the decision of having a stoma made and/or a proctectomy performed. In this review, we describe modern surgical management and the most recent advances in the management of complex PFCD, which will likely impact clinical practice.

The Hyperoxic-Hypoxic Paradox

Effective metabolism is highly dependent on a narrow therapeutic range of oxygen. Accordingly, low levels of oxygen, or hypoxia, are one of the most powerful inducers of gene expression, metabolic changes, and regenerative processes, including angiogenesis and stimulation of stem cell proliferation, migration, and differentiation. The sensing of decreased oxygen levels (hypoxia) or increased oxygen levels (hyperoxia), occurs through specialized chemoreceptor cells and metabolic changes at the cellular level, which regulate the response. Interestingly, fluctuations in the free oxygen concentration rather than the absolute level of oxygen can be interpreted at the cellular level as a lack of oxygen. Thus, repeated intermittent hyperoxia can induce many of the mediators and cellular mechanisms that are usually induced during hypoxia. This is called the hyperoxic-hypoxic paradox (HHP). This article reviews oxygen physiology, the main cellular processes triggered by hypoxia, and the cascade of events triggered by the HHP.

The Hyperoxic-Hypoxic Paradox

Effective metabolism is highly dependent on a narrow therapeutic range of oxygen. Accordingly, low levels of oxygen, or hypoxia, are one of the most powerful inducers of gene expression, metabolic changes, and regenerative processes, including angiogenesis and stimulation of stem cell proliferation, migration, and differentiation. The sensing of decreased oxygen levels (hypoxia) or increased oxygen levels (hyperoxia), occurs through specialized chemoreceptor cells and metabolic changes at the cellular level, which regulate the response. Interestingly, fluctuations in the free oxygen concentration rather than the absolute level of oxygen can be interpreted at the cellular level as a lack of oxygen. Thus, repeated intermittent hyperoxia can induce many of the mediators and cellular mechanisms that are usually induced during hypoxia. This is called the hyperoxic-hypoxic paradox (HHP). This article reviews oxygen physiology, the main cellular processes triggered by hypoxia, and the cascade of events triggered by the HHP.

Ulcerative Colitis: Current and Emerging Treatment Strategies

Historically, medical therapy for ulcerative colitis (UC) was limited to corticosteroids. Excitingly, over the past just 1-2 decades, the options for medical therapy have expanded and include biologics and small molecules, with more agents actively being developed. In this article, we review the current and emerging treatment strategies for UC stratified according to disease severity.

Effect of oxygen-producing suture material on hypoxic colonic anastomoses in an experimental model

Background

Anastomotic leak remains a significant cause of morbidity and mortality after colorectal surgery. Among multiple risk factors considered, hypoxia–ischaemia is considered to be a primary cause of intestinal anastomotic leakage. The aim of this experimental study was to assess safety, usability for surgical tasks, and efficacy of a newly developed oxygen‐producing suture material in the healing of colonic anastomoses under critical conditions.

Methods

An oxygen‐producing suture material was produced that is capable of releasing oxygen directly into the surrounding tissue. Off‐the‐shelf sutures loaded with calcium peroxide nano‐crystals and covered with poly(d,l‐lactide‐co‐glycolide) were assessed in vitro and in a rat model of hypoxic colonic anastomosis.

Results

In vitro assessment showed that these sutures can increase oxygen levels in a hypoxic environment. Potential oxygen byproducts did not seem to have a negative impact on the viability of intestinal cells. The use of oxygen‐producing sutures in vivo resulted in increased tissue oxygen saturation, measured by visible light spectroscopy, and increased mechanical stability of the anastomosis.

Conclusion

Oxygen‐producing suture material increased tissue oxygen saturation and mechanical stability of colonic anastomosis in a rat model.

Advances in Perianal Disease Associated with Crohn's Disease-Evolving Approaches

Perianal diseases, common complications of Crohn's disease, are difficult to diagnose/manage. Patients with perianal Crohn's disease suffer from persistent pain and drainage, recurrent perianal sepsis, impaired quality of life, and financial burden. Conventional medical and surgical therapies carry risk of infection, myelosuppression, incontinence, disease recurrence. Although the phenotype of Crohn's disease has been extensively studied, reported outcomes are inconsistent. Endoanal ultrasonography is also becoming popular because of low cost and ability to acquire images in real time. Emerging management strategies for treatment including laser therapy, local injection of agents, use of hyperbaric oxygen, and stem cell therapy, have demonstrated efficacy.

Contemporary Medical Management of Acute Severe Ulcerative Colitis

Acute severe ulcerative colitis is a medical emergency that requires prompt recognition, evaluation, and intervention. Patients require hospital admission with laboratory, radiographic, and endoscopic evaluation with initiation of corticosteroid treatment. Despite early intervention, many patients require salvage medical therapy, with some progressing to colectomy. Here we review important concepts and recent advances in the evaluation and medical management of adult and pediatric patients with acute severe ulcerative colitis.