Nerve-Sparing Open Radical Retropubic Prostatectomy

Transcription

1 european urology 51 (2007) available at journal homepage: Surgery in Motion Nerve-Sparing Open Radical Retropubic Prostatectomy Thomas M. Kessler, Fiona C. Burkhard, Urs E. Studer *,1 Department of Urology, University of Bern, Bern, Switzerland Article info Article history: Accepted October 4, 2006 Published online ahead of print on October 23, 2006 Keywords: Nerve sparing Open radical retropubic prostatectomy Surgical technique Abstract Introduction: In recent years, the surgical technique for open radical prostatectomy has evolved and increasing attention is paid to preserving anatomic structures and the impact on outcome and quality of life. Methods: Technical aspects of nerve-sparing open radical retropubic prostatectomy (RRP) are described. Patient selection criteria and functional results are discussed, focusing on postoperative urinary continence. Results: The video demonstrates the nerve-sparing open RRP and important steps are elucidated with schematic drawings. The value of nerve sparing, not only for preserving erectile function, but also for preserving urinary continence is discussed and results from our institution are presented. In our series, urinary incontinence was present in 1 of 71 patients (1%) with attempted bilateral nerve-sparing, 11 of 322 (3%) with attempted unilateral nerve-sparing, or 19 of 139 (14%) without attempted nerve-sparing surgery. In multiple logistic regression analysis, the only statistically significant factor influencing urinary continence after open RRP was attempted nerve sparing (odds ratio, 4.77; 95% confidence interval, ; p = ). Conclusions: Nerve-sparing surgery has a significant impact on erectile function and urinary continence and should be performed in all patients provided radical tumour resection is not compromised. For successful nerve preservation we advocate a lateral approach to the prostate to improve visualisation and simplify separation of the neurovascular bundles from the dorsolateral prostatic capsule. Bunching, ligating, and incising Santorini s plexus over the prostate and not over the sphincter ensures a bloodless surgical field. Mucosa-to-mucosa adaptation of the reconstructed bladder neck and the urethra is another important factor to be observed. # 2006 European Association of Urology. Published by Elsevier B.V. All rights reserved. * Corresponding author. Department of Urology, University of Bern, 3010 Bern, Switzerland. Tel ; Fax: address: urs.studer@insel.ch (U.E. Studer). 1 Award: The first video prize was awarded to Urs E. Studer at the 21st Annual European Association of Urology Congress in Paris in 2006 for the DVD presented /$ see back matter # 2006 European Association of Urology. Published by Elsevier B.V. All rights reserved. doi: /j.eururo

2 european urology 51 (2007) Introduction Radical prostatectomy (RP) is an accepted treatment option for patients with organ-confined prostate cancer and a life expectancy of >10 yr who accept the related complications [1]. The associated morbidity has decreased dramatically over the last decade as a result of improvements in the surgical technique [2,3]. One such factor is nerve-sparing surgery, which has a significant positive impact on sexual [4 6] and lower urinary tract function [4,7,8] and has become the gold standard when radical tumour resection is not compromised. In this article the technique of nerve-sparing open radical retropubic prostatectomy (RRP) is described and the anatomic and physiologic considerations on which this technique is based are presented. Patient selection criteria and functional results are discussed with a special focus on postoperative sexual function and urinary continence. 2. Anatomic and physiologic considerations 2.1. Autonomic innervation The pelvic plexus consists of a variable network of both sympathetic and parasympathetic fibres and is located on the lateral aspect of the rectum, bladder, seminal vesicles, and prostate (Fig. 1). Additional fibres join the pelvic plexus directly from the sacral sympathetic ganglia. Mixed sympathetic and parasympathetic fibres from the pelvic plexus supply the pelvic viscera with a dual autonomic innervation. Autonomic fibres from the pelvic plexus, both afferent and efferent fibres, innervate the rectum and the urogenital tract and end as the paraprostatic neurovascular bundle before supplying the urogenital diaphragm, sphincter, and corpora cavernosa Urinary continence mechanism Both the somatic pudendal nerve and autonomic branches of the pelvic plexus are involved in the urinary continence mechanism [9]. Somatic motor innervation passes from the Onuf nucleus in the anterior horn of the sacral segments S2 4 and travels to the external urethral sphincter via an intrapelvic and an extrapelvic branch of the pudendal nerve. Additional intrapelvic extrapudendal nerve fibres from S2 3 pass lateral to the pelvic plexus and then continue along the dorsolateral surface of the rectum until they disappear into the levator ani muscle and terminate in the external urethral sphincter [10]. Autonomic fibres also appear to play a role in urethral sphincter innervation. Sympathetic stimulation results in bladder-neck closure by smooth muscle contraction, thus contributing to urinary continence and preventing reflux of ejaculate into the bladder. The importance of an intact bladder neck is shown by its ability to maintain urinary continence even when external urethral sphincter function has been impaired by traumatic pudendal nerve injury or neurologic diseases. On the other hand, in patients with a completely incompetent bladder neck due to bladder-neck incision or transurethral resection, urinary continence is maintained by an intact external urethral sphincter. The effect of the autonomic innervation on the sphincteric mechanism was convincingly shown by intraoperative stimulation of the neurovascular bundle during RRP. This Fig. 1 Innervation of the pelvic organs in the male. The arrow indicates the line of dissection when performing nerve-sparing open radical retropubic prostatectomy. Reproduced with permission from Kessler et al. Urol Clin North Am 2005;32:

3 92 european urology 51 (2007) results in significant increases in urethral pressure [11]. In addition to the efferent autonomic and somatic nerve fibres innervating the sphincteric musculature, intrapelvic afferents from the membranous urethra contribute to urinary continence [12]. Intact proximal sensation leads to improved urinary continence due to a conscious or unconscious sensation of urine entering the membranous urethra. This induces either a spinal reflex or a voluntary sphincter contraction, resulting in an increased tone of the external urethral sphincter and pelvic floor. These afferent nerve fibres from the membranous urethra are postulated to run in branches of the pelvic plexus or the intrapelvic pudendal nerve, both of which are prone to iatrogenic damage during radical pelvic surgery Sexual function The sympathetic and parasympathetic nervous system both play an important role in sexual function. Sacral parasympathetic fibres from S2 4 travelling through the pelvic plexus and forming the nervi erigentes dorsolateral to the bladder and prostate are responsible for the blood flow into the corpora cavernosa resulting in penile erection. Sympathetic fibres are responsible for emission of semen from the seminal vesicles into the prostatic urethra and antegrade ejaculation. Thus, iatrogenic damage to the parasympathetic and sympathetic pathways during radical pelvic surgery may result in erectile and ejaculation dysfunction. Afferent fibres from the dorsal nerve of the penis pass via the pudendal nerve to the sacral spinal cord, which coordinates sexual response. Descending input arrives from higher centres and efferent fibres travel in the sympathetic, parasympathetic, and pudendal nerves Surgical technique We routinely place patients in a 308 Trendelenburg position with overextension of the pelvis. A urethral catheter is placed and a lower midline incision performed. After meticulous lymph node dissection, particularly along the internal iliac vessels, all fatty tissue covering the endopelvic fascia and surrounding superficial Santorini s vein is removed. The outer layer of the endopelvic fascia is sharply incised medial to the tendinous arc, leaving the puboprostatic ligaments untouched to ensure urethral stability. For nerve sparing, the neurovascular bundle is carefully rolled off the lateral prostate after incision of the second layer of the endopelvic fascia, the periprostatic fascia (Fig. 2 A and B). This is best done from a lateral approach because the plexus can be better visualised and the second layer better identified and separated. If nerve sparing is not indicated at least part of the neurovascular bundle is left on the prostatic capsule and later removed with the prostate specimen. Deep Santorini s plexus is bunched in a curved Babcock clamp and ligated over the apical prostate and at the bladder neck (Fig. 3). The ligated vessels are transected over the ventral aspect of the prostate to avoid damage to the 3. Patients and methods 3.1. Indication for a nerve-sparing procedure Based on these considerations, sparing of the autonomic innervation (both sympathetic and parasympathetic) is important for preservation of sexual and lower urinary tract function. Therefore, we believe that nerve-sparing RP should always be attempted if radical tumour resection is not compromised. Nerve-sparing surgery is not only attempted in patients with preoperative intact sexual function. Patients with erectile dysfunction may also profit from a nerve-sparing procedure especially in regard to urinary continence. Nervesparing surgery is attempted in patients with nonpalpable tumours, if biopsies do not show tumour close to the neurovascular bundle, or if not more than one biopsy is positive on the ipsilateral side. Fig. 2 (A) Sharp dissection of the endopelvic and periprostatic fascia off the lateral wall of the prostate. (B) Separation of the neurovascular bundle from the lateral wall of the prostate. Reproduced with permission from Burkhard et al. [8].

4 european urology 51 (2007) Fig. 3 Bunching of Santorini s plexus including the ventral portion of the endopelvic and the periprostatic fascia with the curved Babcock clamp over the prostatic apex. Ligation over the apex of the prostate and at the bladder neck. Reproduced with permission from Burkhard et al. [8]. urethral sphincter (Fig. 4). The prostatic apex is approached directly along the lateral side of the prostatic capsule towards the membranous urethra, which is then developed out of the donut-shaped prostatic apex. The urethra is transected sharply with scissors (not electrocautery) at the level of the distal verumontanum. Bleeding from Santorini s plexus is controlled, if necessary, by a vertical stitch with a 2-0 polyglycolic acid suture in the coronary plain between Santorini s plexus and the rhabdosphincter, leaving the latter untouched. The suture is then passed a second time perpendicularly to the first, behind the symphysis, thus completely encircling Santorini s plexus. The cranial prostate pedicle is divided by sharp, atraumatic dissection with ligation close to the prostatic capsule on the nerve-sparing side to avoid damage to the proximal portion of the neurovascular bundle. If nerve sparing is not indicated the pedicle is divided about cm from the prostate. Superficial 4-0 polyglycolic acid sutures are placed and tied loosely to control bleeding from the neurovascular bundle. The use of electrocautery is avoided. Following incision of Denonvillier s fascia care is taken to mobilise the seminal vesicles without causing any trauma by squeezing, pulling, or tearing to the adjacent pelvic plexus running along their dorsolateral aspect. The bladder is then opened on the ventral side. After ejaculation of urine has allowed localisation of the ureteral orifices, the trigone is transected 3 5 mm caudal of the interureteric ridge and the prostate removed. Bladder-neck sparing is not attempted. The bladder neck is reconstructed to a width of 8 10 mm using a continuous 2-0 polyglycolic acid seromuscular suture. The bed of the seminal vesicles is oversewn with a continuous 2-0 polyglycolic acid suture to avoid later bleeding and development of a haematoma. Care is taken not to damage the pelvic plexus located lateral to the bed of the seminal vesicles. Six 2-0 polyglycolic acid sutures with a UR-6 needle are placed along an 18F urethral catheter without eversion of the bladder mucosa to ensure a direct mucosa-to-mucosa anastomosis between the resected margin of the proximal urethra and the reconstructed bladder neck (Fig. 5 A D). The two dorsal sutures at 5 and 7 o clock are passed medial to the neurovascular bundles through the remnant of Denonvillier s fascia and the urethral stump (Fig. 6), taking approximately 4 mm of the outre part of the urethra but only including the edge of the mucosa. Two stitches are placed laterally at 3 and 9 o clock and two ventrally at 1 and 11 o clock. The latter are anchored to ligated Santorini s plexus to avoid traction on the sphincter muscle (Fig. 6). All sutures were tied loosely to prevent ischaemia and as a result stricture and shortening of the functional urethral length. In addition to the 18F transurethral silicone catheter, a 10F suprapubic tube ensures bladder drainage. After 7 10 d integrity of the anastomosis is verified by cystography and the transurethral catheter is removed. If extravasation is present, catheter drainage is continued until the radiologic examination shows an intact anastomosis. After complete bladder emptying is verified, the suprapubic catheter is removed the following day. 4. Results Fig. 4 Transection of Santorini s plexus above the prostate and not above the urethral sphincter. Preparation of the donut-shaped prostatic apex along the prostatic capsule. Reproduced with permission from Burkhard et al. [8]. In a recent study [8], we prospectively assessed the role of nerve-sparing surgery on urinary continence after open RRP. One year postoperatively, 505 of 536 patients (94%) were continent; 31 patients (6%) were and remained incontinent. Stress incontinence grade I requiring one or two pads per day was found in 27 of 536 patients (5%) and stress incontinence grade II requiring four to eight pads per day in 4 of 536 patients (1%). No patient had stress incontinence grade III and none underwent implantation of an artificial sphincter. The proportional differences

5 94 european urology 51 (2007) Fig. 5 Anastomosis between the urethra and the bladder neck with the sutures placed at the edge of the mucosa (A and B) to ensure a direct mucosa to mucosa anastomosis (C) without eversion of the bladder mucosa (D). Reproduced with permission from Burkhard et al. [8]. between continent and incontinent patients were highly significant ( p < ) favouring a nervesparing technique. Urinary incontinence was present in 1 of 75 patients (1%) with attempted bilateral nerve-sparing, 11 of 322 (3%) with attempted unilateral nerve-sparing, and 19 of 139 (14%) without attempted nerve-sparing surgery (Fig. 7). In addition, in multiple logistic regression analysis (Table 1), the only statistically significant factor influencing urinary continence after open RRP was attempted nerve sparing (odds ratio, 4.77; 95% confidence interval, ; p = ). 5. Discussion Erectile dysfunction and urinary incontinence are not only the most discussed but also the most disturbing consequences of RP and as a consequence continuing efforts are being made to minimise these side-effects. Taking into consideration that autonomic nerve fibres from the pelvic plexus (including afferent and efferent fibres) form the nervi erigentes responsible for penile erection and also innervate the sphincteric mechanism, it makes sense that preservation of the autonomic nerves

6 european urology 51 (2007) Fig. 6 For construction of the anastomosis dorsal sutures are placed through the remnant of Denonvillier s fascia and the urethral stump medial to the neurovascular bundles to avoid damage and ventral through ligated Santorini s plexus to avoid traction on the sphincter muscle. Reproduced with permission from Kessler et al. Urol Clin North Am 2005;32: may have an impact on sexual and lower urinary tract functions. Thus, a nerve-sparing technique was developed and has since become the gold standard when radical tumour resection is not compromised. Since introduction of the nerve-sparing technique, potency rates after RP have substantially Fig. 7 Proportion of continent and incontinent patients in relation to attempted nerve-sparing open radical retropubic prostatectomy. The overall continence rate was 94%. With bilateral or unilateral attempted nerve sparing or without attempted nerve sparing, continence rates were 99%, 97%, and 86%, respectively. The majority of the incontinent patients and all patients with stress incontinence grade II had no attempted nerve sparing. Reproduced with permission from Burkhard et al. [8]. increased. However, not only the number of spared neurovascular bundles but also age and preoperative potency status contribute to recovery of sexual function [6]. The aetiology of erectile dysfunction following RP is multifactorial. However, neurogenic factors seem to be the most important [6]. In sexually active men with organ-confined disease, bilateral nerve-sparing surgery preserved erectile function in 32 86% and unilateral nerve-sparing surgery in 13 56% [5,13 17]. Vascular factors, however, may also play a role. Ageing men have a greater risk for cardiovascular disease and the operation itself may additionally compromise penile arterial blood flow [6]. However, more prospective studies on vascular involvement are required to fully understand its role in erectile dysfunction after RP. Controversy persists as to the role of nervesparing surgery on urinary continence. A clear benefit in patients self-assessed postoperative recovery of urinary continence using a nervesparing approach was demonstrated [4] and intraoperative electrophysiologic assessment revealed that bilateral nerve-sparing surgery contributes to early recovery of urinary continence [18]. In addition, bilateral neurovascular bundle resection was an independent risk factor for urinary incontinence [7,19]. This is in line with our observations [8] that preservation of the neurovascular bundle improves the patients chance of remaining continent after

7 96 european urology 51 (2007) Table 1 Multiple logistic regression analysis of factors potentially influencing urinary continence after open radical retropubic prostatectomy OR 95% CI P Age Follow-up Preoperative PSA Pathological tumor stage Pathological lymph node status Gleason score Attempted nerve sparing OR = odds ratio; 95% CI = 95% confidence interval for odds ratio; PSA = prostate-specific antigen. Attempted nerve sparing was the only factor influencing urinary continence. (Reproduced with permission from Burkhard et al. [8].) open RRP. However, in other large series a significant effect was not observed [20 22] and it seems that good results may be obtained in the majority of patients, even if no attention is paid to nerve sparing. This was also observed in our series, where 86% of patients remained continent without nerve sparing [8]. This may be attributable, at least in some cases, to inadvertent total or partial preservation of nerves. Not surprisingly a discordant rate of nerve-sparing or non nerve-sparing surgery between electrophysiologic and macroanatomic assessment of about 20% has been shown [18,23]. Additionally, other factors such as age, detrusor dysfunction (decreased sensitivity and overactivity), insufficiency of the sphincter mechanism, and decreased urethral sensitivity may contribute to urinary incontinence. Nonetheless, there does seem to be at least a subset of patients who benefit from attempted nerve sparing. Some concern was voiced over the incidence of positive surgical margins in nerve-sparing procedures. However, in carefully selected patients, nerve sparing is an oncologically safe procedure and was not found to be an adverse factor for tumour recurrence [24]. This underlies the importance of appropriate patient selection. 6. Conclusions Nerve-sparing surgery has a significant impact on erectile function and urinary continence and should be performed in all patients provided radical tumour resection is not compromised. A lateral approach to the prostate allows better visualisation and separation of the neurovascular bundles from the periprostatic fascia is easier on the dorsolateral prostate capsule. Bunching, ligating, and incising Santorini s plexus over the prostate and not over the sphincter ensures a literally bloodless surgical field and helps minimise damage to the neurovascular bundle by mechanical stress and electrocautery. Appendix A. Supplementary data Supplementary data associated with this article can be found, in the online version, at doi: / j.eururo and via com. Subscribers to the printed journal will find the supplementary data attached (DVD). References [1] Aus G, Abbou CC, Bolla M. et al. EAU guidelines on prostate cancer. files/guidelines/07%20prostate%20cancer.pdf. [2] Myers RP. Improving the exposure of the prostate in radical retropubic prostatectomy: longitudinal bunching of the deep venous plexus. J Urol 1989;142: [3] Walsh PC. Anatomic radical prostatectomy: evolution of the surgical technique. J Urol 1998;160: [4] Kübler HR, Tseng TY, Vieweg J, Harris MJ, Dahm P. Impact of the nerve-sparing technique on patients self-assessed functional outcome in radical perineal prostatectomy. J Urol Suppl 2006;175:519 (abstract no. 1610). [5] Michl UH, Friedrich MG, Graefen M, Haese A, Heinzer H, Huland H. Prediction of postoperative sexual function after nerve sparing radical retropubic prostatectomy. J Urol 2006;176: [6] Dubbelman YD, Dohle GR, Schröder FH. Sexual function before and after radical retropubic prostatectomy: a systematic review of prognostic indicators for a successful outcome. Eur Urol 2006;50:711 8, discussion [7] Sacco E, Prayer-Galetti T, Pinto F, et al. Urinary incontinence after radical prostatectomy: incidence by definition, risk factors and temporal trend in a large series with a long-term follow-up. BJU Int 2006;97: [8] Burkhard FC, Kessler TM, Fleischmann A, Thalmann GN, Schumacher M, Studer UE. Nerve sparing open radical retropubic prostatectomy does it have an impact on urinary continence? J Urol 2006;176:

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