Surgical Techniques for Managing Post-Prostatectomy Erectile Dysfunction
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Curr Urol Rep (2017) 18: 90 DOI 10.1007/s11934-017-0735-2 UROSURGERY (P SOORIAKUMARAN, SECTION EDITOR) Surgical Techniques for Managing Post-prostatectomy Erectile Dysfunction Fabio Castiglione1 & David J. Ralph1 & Asif Muneer1,2 Published online: 30 September 2017 # The Author(s) 2017. This article is an open access publication Abstract preservation and nerve graft, nerve-sparing surgery and penile Purpose of Review Due to the increasing numbers of radical prostheses represent, today, the only methods to permanently prostatectomies (RP) performed for prostate cancer, a substan- and definitively preserve or erectile function after RP. tial number of patients are now suffering from post-operative erectile dysfunction (ED). The aim of this study is to summa- Keywords Erectile function after radical prostatectomy . rize the current literature on surgical techniques for managing Nerve-sparing radical prostatectomy . Radical prostatectomy post-prostatectomy erectile dysfunction. outcome Recent Findings The PubMed database was searched for English-language articles published up to Jan 2017 using the following search terms: “prostatectomy AND erectile dys- function”, “prostatectomy AND penile prostheses”,and Introduction “prostatectomy AND penile implants”. All of the studies that evaluated medical treatment were excluded. In the last few The evolution of prostate cancer management has now taken a decades, the understanding of the anatomy of the male pelvis paradoxical turn. Large longitudinal studies investigating the and prostate has improved. This has led to significant changes role of active surveillance have made it clear that more than 40 in the nerve-sparing radical prostatectomy techniques, with to 50% of prostate cancers detected in the prostate-specific the aim of preserving post-surgical erectile function (EF). In antigen (PSA) era are indolent [1]. Despite these findings, this scenario, the prostate vascular supply and the anatomy of thousands of asymptomatic men suffering from a potentially the neurovascular bundles have a central role. Penile prosthe- harmless disease still undergo aggressive surgical treatment, sis implantation is considered the third-line treatment option and as a result, prostate cancer survivors are at risk of iatro- forRPEDpatients,andtheyhavebeenreportedtobeavery genic erectile dysfunction (ED). It has been postulated that successful treatment with the highest patient satisfaction rate. only 10 to 23% of men aged below 60 years regain their Summary Considering the failure of penile rehabilitation, and baseline potency after bilateral nerve-sparing radical prosta- the lack of evidence for accessory pudendal artery (APA) tectomy (NSRP) [2–4]. The use of robot-assisted radical pros- tatectomy (RARP) has not significantly reduced these post- operative ED rates [5]. A recent prospective trial comparing RARP to open retropubic radical prostatectomy (RRP) This article is part of the Topical Collection on Urosurgery showed that only 29.6% of patients did not suffer from ED * Asif Muneer at 1 year following open RRP compared with 25.3% after [email protected] RARP, despite RARP patients having a better performance status and more likely to undergo a nerve-sparing procedure 1 Department of Andrology, University College London Hospital, 250 [5]. Surprisingly, these rates from a real-life setting are tem- Euston Road, London NW1 2PG, UK pering the initial enthusiasm about the functional outcomes of 2 NIHR Biomedical Research Centre, University College London anatomical radical prostatectomy that has been growing over Hospital, London, UK the past two decades. 90 Page 2 of 9 Curr Urol Rep (2017) 18: 90 This scenario is further complicated by the widespread use Pathophysiology of Post-prostatectomy ED: Is It of various penile rehabilitation protocols, despite this being aNeuronalProblem? short of a solid evidence base [6]. In a survey conducted by the International Society for Sexual Medicine (ISSM) mem- Penile erection is based on neurovascular pathways orchestrat- bers from 41 countries, over 95% routinely prescribed phos- ed by psychological, emotional and hormonal factors where phodiesterase type 5 inhibitors (PDE5i) to their prostatectomy the interplay both neuronal and vascular components are cru- patients, as part of a penile rehabilitation protocol [7]. For cial and indispensable. A penile erection requires neurotrans- patients wishing to maintain the ability to have sexual inter- mitters, such as nitric oxide (NO) and Prostaglandins, released course and in whom pharmacological options have failed, by the cavernous nerve (CN) terminals, which provide para- end-stage treatment using penile prostheses surgery is an sympathetic innervation to the corpora cavernosa. These neu- option. rotransmitters induce the relaxation of the smooth muscle of The aim of the present study was to review the current the arteries and of the cavernosal smooth muscle [11]. surgical treatments for ED after radical prostatectomy. The CN terminals arise from the pelvic plexus that is locat- ed within the fibro-fatty plane between the bladder and the rectum, and they run in close vicinity to the tips of the seminal vesicles along the dorsolateral aspect of the prostate, between Methods the capsules of the prostate. These fibers run together with blood vessels and comprise the neurovascular bundles The PubMed database was searched for English-language ar- (NVBs) as described by Walsh et al. [12, 13•, 14, 15]. ticles published up to Jan 2017 using the following search Erectile dysfunction after non-nerve-sparing radical pros- terms: “prostatectomy AND erectile dysfunction”, “prostatec- tatectomy is an inevitable consequence of the deliberate or un- tomy AND penile prostheses”,and“prostatectomy AND pe- wanted transection of the CN. nile implants”. This review is primarily focused on the litera- In contrast, erectile dysfunction after nerve-sparing radical ture published within the past 10 years, although older papers prostatectomy (NSRP) is a complex mechanism and still not closely related to this topic are also included. The present completely understood. However, it is now clear that age co- review evaluated only selected studies, evaluating the surgical morbidities such as pre-operative erectile function are inde- therapy for erectile dysfunction after radical prostatectomy. pendent prognostic factors for the recovery of erectile function All of the studies that evaluated medical treatment were following surgery [16–18]. excluded. A few days after nerve-sparing surgery, ED is a result of iatrogenic functional damage (traction injury, diathermy) to the periprostatic neurovascular bundle, which results in neuropraxia which is evident immediately after prostatectomy Erectile Dysfunction After Radical Prostatectomy: with loss of nocturnal and sexually stimulated erections. How Big Is the Problem? Urologists and patients may note moderate erectile activity shortly after surgery, such as at the time of catheter manipulation In the last decades, several studies have investigated the or removal. These events may bring about high hopes for recov- incidence of ED following RP with different and some- ery of erectile function, but the nerves are partially conductive times conflicting results. Factors such as the different until the ensuing Wallerian degeneration has set in several days classification and evaluation of EF, patient selection following the neuropraxia. The resulting denervation of the cor- criteria, the surgical technique used and the different pora cavernosa results in a decrease in the rate and quality of penile rehabilitation treatment account for this wide var- early morning and nocturnal erections, and thus promotes persis- iability. EF recovery rates after an open radical prosta- tent cavernous hypoxia, as oxygenated blood is mainly supplied tectomy have been reported to range from 31 to 86% during erectile activity [19–21]. Both in vitro and in vivo studies [8]. Equally, potency rates for laparoscopic RP (LRP) support the theory that penile hypoxia results in collagen accu- have been showed to range from 42 to 76% [9]. mulation, smooth-muscle apoptosis and ultimately cavernosal More recently, Ficarra et al. published a meta- fibrosis. Finally, these changes within the corpus cavernosum analysis of a RARP series and reported potency recov- contribute to venous leakage and permanent ED, even if the ery rates of 32 to 68%, 50 to 86%, 54 to 90% and 63 normal function of the nerves return [22]. to 94% at 3, 6, 12 and 24 months after surgery, respec- It has been postulated that another mechanism involved in tively [10••]. The study analysed 15 case series, 6 stud- post-prostatectomy ED may be the injury of the accessory ies comparing different techniques in the context of pudendal arteries [23], which have been described in up to RARP, 6 studies comparing RARP with RRP and 4 75% of patients, and could lead to the development of penile studies comparing RARP with LRP [10••]. hypoxia [23]. Curr Urol Rep (2017) 18: 90 Page 3 of 9 90 Finally, recent results from Salamanca’sgroup[23]have common type was the apical accessory pudendal arteries shown that neurogenic contractile responses (sympathetic) are (pooled prevalence estimate 60.9%). increased in the corpus cavernosum (CC) of rats following Numerous reports have shown that an injury to the APA cavernous nerve injury and in cavernosal tissues from men can induce vasculogenic ED. Conversely, Box et al. recently suffering with post-RP ED. This is simultaneous to a profound