Sub-Albuginean Adipocyte Accumulation is Associated with Erectile Dysfunction: First Clinical Evidence and Pathophysiological Implications

Abstract

INTRODUCTION & OBJECTIVES: In animal models, cavernous adipocyte accumulation is thought to impair penile vascular performance, leading to venous leakage and lack of normal tumescence. We hypothesized that penile sub-albuginean fat accumulation is associated to refractory Erectile Dysfunction (ED). In the present study, we compared the histology of the penile sub-albuginean region of refractory ED patients undergoing penile prosthesis implantation with potent patients with Peyronie's Disease (PD) undergoing curvature correction procedures (Plaque incition/excition/grafting). MATERIAL & METHODS: This is an international multicenter case-control study, in which 17 refractory ED patients (non responders to PD5 inhibitors and intra-cavernous/intra-urethral alprostadil) and 14 potent patients with Peyronie's disease underwent penile prosthesis implantation and curvature correction surgeries, respectively. In both groups, sub-albuginean tissue samples were taken within the operative time. An expert uropathologist analysed each section, searching for adipocyte-like images under tunica albuginea. A bivariate analysis was performed. P value was considered significant. RESULT(S): 31 patients were included in the study. 17 patients with ED and 14 potent patients with PD. Of the 17 patients in the ED group, 11 presented cavernous fat cell accumulation, while only 1 patient in the potent group presented this finding (p<0.05). Adipocyte accumulation was significantly higher in ED patients compared with potent patients. Unadjusted and adjusted OR were 24 and 41, respectively. CONCLUSION(S): This is the first study in humans to report an association between ED and penile sub-albuginean fat accumulation. Normally, subalbuginean stem cells differentiate into a muscle lineage. Novel animal studies have shown that mature differentiated smooth muscle cells may suffer apoptosis and trans or de-differentiation into adipocytes. We believe that venous leakage secondary to accumulation of fat under tunica albuginea of the penis may be an important element in the pathophysiology of ED, especially in patients that do not respond to oral or intra-cavernous therapy.