Predictive factors for return of erectile function in radical prostatectomy: postoperative haemodynamic profiles and their correlation with the recovery of erectile function
Radical prostatectomy is associated with a loss of sexual potency in the majority of cases, due to injury to the autonomic cavernous nerves. Despite the advent of nerve sparing radical prostatectomy (the operation of choice in potent and sexual active men with organ confined disease), some men suffer with erectile dysfunction. There are several recognized factors correlated with the post-operative incidence of erectile difficulties. Predicitive factors are classically divided in pre-operative ( in particular age, baseline I.I.E.F., and status of comorbid conditions), intra-operative ( like surgical techniques, surgical volume and surgical skill) and post-operative (in particular pathological stage, response to PDE5 inhibitors and response to intracavernous injections)1-2. We evaluate the role of post-operative penile's haemodynamic at sixth month in fourty-eight patients with a normal pre-operative erectile function. Doppler ultrasonography is an effective, reliable and non-invasive and cheap mean of evaluating penile arterial and venous function.
Materials and Methods
From June 2013 to December 2013, 48 patients with prostate cancer underwent bilateral nerve-sparing radical prostatectomy at our hospital by the same surgeon. The average age of these patients was 59–68 years.
They had not any important comorbidities (hypertension, hypercholesterolemia, vascular disease and diabetes). 30 of 48 patients underwent laparoscopic radical prostatectomy (LRP) and 18 of 48 patients underwent open retropubic radical prostatectomy. Each patient had a normal erectile function before surgery ( I.I.E.F. score between 26 to 30 and SHIM score between 22 to 25). None patient had rehabilitative therapy with PDE5 inhibitors, vacuum devices or intracavernous injections after radical prostatectomy. After six month all patients underwent a Doppler ultrasonography in order to evaluate penile's post-operative haemodynamic. At 12th month we surveyed these patients using the same self-administered questionnaire ( I.I.E.F. and SHIM ) during an andrological consultation.
We found a normal vascular status, arterial insufficiency and venous leakage in 52% (25 of 48) , 31% (15 of 48) and 17% (8 of 48) of the men, respectively.
Recovery of sexual potency, defined as the ability to penetrate and complete intercourse, was found in 90% (37 of 48) of men who underwent radical prostatectomy (20 LRP and 17 RRP). In this patients, I.I.E.F. score at 12th month was between 23 and 27, and SHIM score between 21 to 23. 65% (24 of 37) of men who had a recovery of sexual potency had a normal penile's haemodynamic, 24% (9 of 37) had an arterial insufficiency (peak systolic velocity < 35 cm/sec) and 11% (4 of 37) a veno-occlusive mechanism deficit (resistence index <0,75) . None of patients that suffered with both arterial insufficiency and veno-occlusive mechanism deficit, had a recovery of sexual potency 12 months post-operatively.
Post-operative penile's haemodynamic at sixth month relates with erectile function recovery. Even if we have not studied patients who underwent rehabilitative therapy with PDE5 inhibitors, vacuum devices or intracavernous injections after radical prostatectomy, these therapies could help patients to improve their penile's haemodynamic. Veno-occlusive mechanism disfunction is a clear negative prognostic factor for recovery of sexual potency. In fact around fifty percent of patients with veno-occlusive mechanism disfunction did not recovery a good sexual function. Significant levels of apoptosis in smooth muscle cells and an increase in extracellular protein, as postulated in corporeal fibrosis, revealed a mechanism for veno-occlusive dysfunction observed after radical prostatectomy.
Our analysis confirms that doppler ultrasonography is an important mean of evaluating post-operative penile vascularization and can be useful to understand the probability of recovery of sexual potency in patient who underwent a nerve-sparing radical prostatectomy (both laparoscopic, robotic and open retropubic radical prostatectomy). Colour Doppler ultrasound appears to be the most reliable, non-invasive diagnostic test for erectile dysfunction after radical prostatectomy also in patients who do not respond to pharmacotherapy. More prospective studies on vascular involvement are required for full understanding of its role in post-radical prostatectomy sexual dysfunction, including an analysis of the vascular status before the procedure.
1- Salonia A. et all., Prevention and management of postprostatectomy sexual dysfunctions. Part 1: choosing the right patient at the right time for the right surgery.Eur Urol. 2012 Aug;62(2):261-72. doi: 10.1016/j.eururo.2012.04.046. Epub 2012 May 3.
2-Dubbelman YD et all., Sexual function before and after radical retropubic prostatectomy: A systematic review of prognostic indicators for a successful outcome. Eur Urol. 2006 Oct;50(4):711-8; discussion 718-20. Epub 2006 Jun 27.
3- User H.M. et. all,Penile weight and cell subtype specific changes in a post-radical prostatectomy model of erectile dysfunction. J Urol. 2003 Mar;169(3):1175-9.