Hyperbaric Oxygen Therapy for
Erectile Dysfunction
Erectile dysfunction (ED) is often caused by inadequate blood flow to the penis, either due to microvascular or macrovascular insufficiency. Recent studies have suggested that hyperbaric oxygen therapy (HBOT) has the potential to promote the formation of new blood vessels (angiogenesis) in various organs of the body. However, the specific effects of HBOT on ED that is not related to surgical interventions have not yet been investigated.
The objective of the current study was to examine the effects of HBOT on sexual function and the blood vessels within the penis in patients with non-surgical ED. The study involved a prospective analysis of patients with chronic ED who underwent 40 daily HBOT sessions. The clinical efficacy of HBOT was evaluated using the International Index of Erectile Function questionnaire (IIEF) and a global efficacy question (GEQ). Additionally, the impact of HBOT on the penile vascular bed was assessed using perfusion magnetic resonance imaging (MRI).
Discussion
The findings of this study provide novel evidence that hyperbaric oxygen therapy (HBOT) can induce penile angiogenesis and improve erectile function in men with chronic non-surgical erectile dysfunction (ED). The improvements in sexual performance were significant across all domains of the International Index of Erectile Function questionnaire (IIEF), with notable enhancements observed in erectile function and overall efficacy according to the global efficacy question. The use of perfusion magnetic resonance imaging (MRI) confirmed the occurrence of penile angiogenesis.
Vascular health and proper blood flow to the cavernous sinusoidal system are vital for normal penile erections. Conditions such as endothelial dysfunction, atherosclerosis, and microvascular diseases can impair penile blood flow, making vascular factors the leading cause of ED. Given the relatively small diameter of penile arteries compared to other arteries, even mild endothelial dysfunction and atherosclerosis can have a more pronounced impact on penile blood flow, leading to ED. Therefore, ED can serve as an early indicator of underlying cardiovascular disease.
Angiogenesis involves the development of new blood vessels through the differentiation of vasculogenic stem cells into endothelial cells and other supportive structures. Previous studies have explored the potential use of stem cells and angiogenic growth factors to treat ED. Animal models have shown promising results using intracavernosal injections of bone marrow stem cells and vascular endothelial growth factor (VEGF). HBOT sessions, through the mobilization of vasculogenic stem cells and the release of angiogenic factors like VEGF and HIF-1alpha, can induce similar effects. Recent research involving patients with chronic neurological impairments stemming from stroke, traumatic brain injury, and anoxic brain injury has demonstrated that HBOT promotes brain angiogenesis and exerts neurotherapeutic effects.
One characteristic of newly formed blood vessels is their relatively high leakage compared to normal blood vessels. This characteristic has been utilized to demonstrate angiogenesis using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). In this study, the use of DCE-MRI and the observation of higher K-trans values after hyperbaric oxygen therapy (HBOT) clearly demonstrated the induction of angiogenesis in the corpus cavernosum of the penis. The angiogenesis observed in the penis may be one of the underlying physiological mechanisms responsible for the positive clinical effects of HBOT on erectile and sexual functions.
When compared to other treatments for erectile dysfunction (ED), such as phosphodiesterase type 5 inhibitors (PDE5Is) or penile injections, HBOT offers several advantages and disadvantages. One of the major advantages is that HBOT aims to address the underlying vascular pathology and promote long-term resolution rather than providing short-term symptomatic relief. Unlike PDE5Is, which require pre-planning and preparation before sexual intercourse, HBOT allows for spontaneous or unplanned sexual activity.
Additionally, diabetic patients showed similar efficacy with HBOT, whereas they may experience lower efficacy with PDE5Is. Another significant advantage is the high potency of HBOT, even in men who do not respond to PDE5Is. In the study population, all participants had persistent ED for an average of 4.2 years and had previously used PDE5Is without satisfactory results. HBOT, however, is not without disadvantages. Firstly, the beneficial effects of HBOT, like other regenerative therapies, may only become evident after a series of treatment sessions, whereas PDE5Is or intracavernosal injections have an immediate effect. Secondly, HBOT requires a significant time commitment, with 40 daily treatments lasting 90 minutes each.
Hyperbaric oxygen therapy (HBOT) is generally considered a safe treatment method, including for patients with vascular-related conditions and erectile dysfunction (ED). The main adverse effects of HBOT typically involve mild and temporary middle ear or sinus barotraumas, which resolve completely within a few days. In the present study, the six patients who discontinued HBOT due to barotrauma could have safely continued the treatment if they had chosen to do so.
The study has a few limitations. Firstly, the number of patients involved is relatively small. However, despite the small sample size, the statistically significant effect observed through pairwise analysis holds considerable power (100%). Secondly, the study lacks an appropriate control or placebo group. Nonetheless, significant improvement in the International Index of Erectile Function (IIEF) questionnaires within three months would not be expected in men with long-standing ED. Moreover, objective analysis of perfusion MRI clearly demonstrated improvement in penile perfusion, which correlates with the clinical findings and strengthens the study results. Thirdly, HBOT is a relatively costly therapy compared to standard medications commonly used for ED.
This study represents the first evaluation of HBOT in patients with chronic non-surgical ED. Further studies are necessary to identify the specific subgroups of patients who may benefit most from this treatment and to determine the optimal HBOT protocol for those individuals.
In conclusion, HBOT can induce penile angiogenesis and improve erectile function in men with ED. It addresses the underlying pathophysiology of atherosclerosis and decreased penile perfusion, which are responsible for a majority of ED cases. This treatment can be considered even years after the onset of erectile dysfunction and in men who have not responded satisfactorily to phosphodiesterase type 5 inhibitors (PDE5Is). Additional studies are needed to further evaluate which subgroups of men can derive the greatest benefit from HBOT.