ORIGINAL ARTICLE Recovery of sexual function after nerve-sparing radical retropubic prostatectomy: is cavernous nitric oxide level a prognostic index? A Zucchi 1 , G Arienti 2 , L Mearini 1 , E Costantini 1 , V Bini 1 , M Porena 1 and CA Palmerini 2 1 Department of Urology, University of Perugia, Perugia, Italy and 2 Department of Internal Medicine, University of Perugia, Perugia, Italy The preservation of NANC nerve fibers (producing nitric oxide, NO) is necessary for erection recovery after retropubic radical prostatectomy (RRP). Yet, it is impossible to establish when and if a patient will recover erections; therefore, we investigate the prognostic value of cavernous blood NO levels on this parameter. Nerve-sparing RRP was performed on 14 patients for localized prostate cancer. We evaluated all patients 3 months after surgery by IIEF score: no patients had erections. A cavernous blood sample was also taken to determine NO levels (as nitrite). Patients were evaluated again 18 months after surgery. In six cases, erectile function was compromised, whereas in seven cases, potency was restored. Statistical analysis showed a relationship between nitrite levels in cavernous blood 3 months after surgery and the recovery or erectile function at 18 months. We propose that cavernous NO blood levels are a prognostic index of erection recovery. International Journal of Impotence Research (2006) 18, 198–200. doi:10.1038/sj.ijir.3901392; published online 8 September 2005 Keywords: erectile dysfunction; nerve-sparing radical retropubic prostatectomy; nitric oxide Introduction Erectile dysfunction often follows radical retropubic prostatectomy (RRP). Previous studies have shown that the recovery of erectile function occurs in 41– 69% of subjects in a period ranging from 6 to 18 months, provided that at least one of the neuro- vascular bundles is preserved. 1–3 Data in the experimental animal have shown that the improvement and the recovery of erectile function is probably due to the regeneration of nerve fibres, particularly those producing nitric oxide (NANC fibres). 4–6 The interruption of NANC fibres, during radical prostatectomy, leads to perma- nent erectile dysfunction, whereas the preservation of at least one neurovascular bundle permits nerve regeneration and the spontaneous recovery of erectile activity within 6–18 months. 4 Nitric oxide (NO) is one of the most important mediators of the complex mechanism involved in erection and it is formed by NO synthase (NOS). 7–11 Three different NOS isoforms (I, II, III) occur in human tissues. 5 In bilateral neurological damage, isoform I decreases and isoforms II and III alone are not able to produce the NO levels necessary for achieving erection, unless the nerve pathway is also intact. For this reason, it is extremely important to preserve, at least partially, the neurovascular bun- dles during surgery not only to ensure proper NOS levels but also, above all, to promote regeneration of the fibres producing NO. In most patients, it is not possible to establish previously if and when erectile function will be recovered after NS-RRP. Therefore, the aim of our study is to correlate the spontaneous recovery of erectile function 18 months after surgery and cavernous blood NO (nitrite) levels 3 months after surgery, as prognostic value after NS-RRP. Patients and methods Patients From January 2002 to January 2003, we performed monolateral or bilateral nerve-sparing RRPs on 14 patients with a mean age of 61 years (range 55–68 years) affected by clinically localized prostate cancer (T1–T2). All patients were evaluated Received 20 April 2005; revised 7 June 2005; accepted 15 June 2005; published online 8 September 2005 Correspondence: Professor G Arienti, Department of Inter- nal Medicine, University of Perugia, Via del Giochetto, Perugia I-06128, Italy. E-mail: arienti@unipg.it International Journal of Impotence Research (2006) 18, 198–200 & 2006 Nature Publishing Group All rights reserved 0955-9930/06 $30.00 www.nature.com/ijir