Original Cavernous tissue rehabilitation with sildenafil 100 mg following radical prostatectomy Manuel Fernández Arjona, Luis M. Herranz Fernández, Pablo Garrido, Milagros Jiménez, Carlos Suárez, Inmaculada Fernández Service of Urology Hospital del Henares. Coslada, Madrid, Spain Service of Urology Hospital Universitario de La Princesa. Madrid, Spain ACTAS UROLÓGICAS ESPAÑOLAS 2009;33(4):378-385 Abstract Objectives: A study is made to determine whether early penile rehabilitation ameliorates erectile dysfunction secondary to radical prostatectomy. Material and methods: A retrospective study was made of 80 patients operated upon between 2005-2008. All underwent radical prostatectomy and were treated with sildenafil 100 mg every second day (Monday, Wednesday and Friday) plus 100 mg on demand after surgery. As objective measurements, we used the validated IIEF-5 questionnaire and also axial penile rigidity before and after surgery in the third and ninth month. Results: Patients treated with sildenafil at fixed doses presented 60% full erection recovery 9 months after radical prostatectomy. In the case where patients underwent bilateral or unilateral nerve sparing procedures, the success rate was almost 90%. Even 20% of those patients who did not have nerve preservation obtained satisfactory erections. Conclusions: Our experience shows early penile rehabilitation to be a good management option for erectile dysfunction after radical prostatectomy with PDE5 inhibitors at fixed doses. Administration every other day plus on demand also appears to be an appropriate option. Keywords: Penile rehabilitation. Radical prostatectomy. Erectile dysfunction. PDE5 inhibitors. Patients subjected to radical prostatectomy due to prostate cancer experience a series of cavernous tissue changes that lead to erectile dysfunction. In general, such alterations are found fundamentally at neurogenic and vascular level. These patients suffer a lack of oxygen supply during spontaneous and provoked erection, resulting in cavernous tissue hypoxia. Such hypoxia in turn can give rise to an increased presence of collagen fibers secondary to the mediation of a series of growth factors, giving rise to vascular smooth muscle fibrosis and ultimately failure of the corporal veno-occlusive mechanism 1-3 . Nerve involvement in turn causes variations in the production of nitric oxide. The latter acts at endothelial cell level upon the enzyme guanylate cyclase, which favors smooth muscle relaxation through a calcium exchange mechanism 4,5 . Sildenafil, as a 5-phosphodiesterase (PDE5) inhibitor, intervenes in nitric oxide metabolism, favoring the intracellular concentration of cyclic guanylate monophosphate (cGMP), and thus facilitating cavernous smooth muscle relaxation 1,3 . A number of studies have suggested that sildenafil acts upon nitric oxide synthase A2, and through the modulation of cGMP favors cavernous tissue oxygenation, reducing tissue oxidative stress and contributing to protection of the smooth muscle cells 10 . Its biochemical properties have led to the exploration of possible treatments, including the restoration of erection capacity in patients following radical prostate cancer surgery 5-9 . Based on the above physiopathological concepts, the term “endothelial rehabilitation” of the corpus cavernosum has been introduced in reference to the prevention of cavernous tissue degeneration by using 5-phosphodiesterase inhibitors, among others, with a view to securing