Surgical Techniques A Comparison of Outcomes for Interfascial and Intrafascial Nerve-sparing Radical Prostatectomy

Transcription

1 Surgical Techniques A Comparison of Outcomes for Interfascial and Intrafascial Nerve-sparing Radical Prostatectomy Jens-Uwe Stolzenburg, Panagiotis Kallidonis, Do Minh, Anja Dietel, Tim Häfner, Robert Rabenalt, George Sakellaropoulos, Roman Ganzer, Uwe Paasch, Lars Christian Horn, and Evangelos Liatsikos OBJECTIVE METHODS RESULTS To compare the outcome of intrafascial nerve-sparing endoscopic extraperitoneal radical prostatectomy (nseerpe) with interfascial (standard) nseerpe. Four-hundred patients underwent nseerpe; 200 patients underwent bilateral intrafascial nseerpe (group A) and 200 bilateral standard nseerpe (group B). Tumor stages of T1 and T2a, prostate-specific antigen level 10 ng/ml, maximal Gleason score 3 4 (not 4 3) and preoperative potency were considered as candidates for nseerpe. Patients were randomized to the aforementioned groups. Perioperative data, and functional and oncological outcome were reviewed. Patients not requiring any pads or requiring 1 pad for safety were defined as continent. Patients responding positively to sexual encounter profile diary question numbers 2, 3, and 5 were considered as potent. Perioperative data were similar between groups. At 3 months, 74% of group A and and 63% of group B were continent. At 6 months, the respective figures were 87.9% and 76.2%, respectively (A, B). At 12 months, 93.2% of group A and 90.7% of group B were continent. Potency rates of group A were 93.5% ( 55 years), 83.3% (55-65 years), and 60% ( 65 years) at 12 months. The respective figures for were 77.1%, 50%, and 40%. Positive surgical margins were detected in 9% and 9.5% of groups A and B, respectively. CONCLUSIONS Intrafascial nseerpe provides significantly better potency in patients 55 years of age at 12 months and in patients years of age at 6 and 12 months, with probably limited effect on the oncological outcome. Significantly improved continence was observed at 3 and 6 months in favor of intrafascial nseepre. UROLOGY 76: , Elsevier Inc. Laparoscopic and robotic radical prostatectomy have been introduced and significantly evolved in the recent years. 1 The experience with extraperitoneal endoscopic radical prostatectomy (EERPE) revealed surgical and oncological results similar to those of transperitoneal laparoscopic radical prostatectomy (LRP). In addition, the extraperitoneal approach was associated with avoidance of the intraperitoneal complications while preserving the advantages of the minimally invasive surgery and retropubic approach. Our experience counts for more than 2400 cases, with results directly comparable with open radical prostatectomy and LRP. 2 The initial technique of EERPE has undergone several refinements From the Department of Urology, University of Leipzig, Germany; Department of Urology, University of Patras, Greece; Department of Medical Physics, University of Patras, Greece; Department of Urology, University of Regensburg, Germany; and Department of Dermatology and Andrology and Pathology, University of Leipzig, Germany Reprint requests: Evangelos N. Liatsikos, M.D, Ph.D., Assistant Professor, Department of Urology, University of Patras Medical School, Rion, , Patras, Greece. liatsikos@yahoo.com based on updated anatomical studies in an attempt to maximize the functional outcome of the procedure without compromising the oncological efficacy, resulting in improvement of postoperative continence and potency. 2,3 Current evidence on the anatomical structures of the pelvis suggests that the neurovascular bundles (NVB) are not just confined to a single dorsolateral bundle but consist of periprostatic nerves of variable distribution, with a high percentage of these nerves in a ventrolateral and dorsal position. 4-9 Moreover, the course of NVB is likely to differ from the actual course of the cavernous nerve and may be following an axial course through the pararectal space and rectourethral muscle. Thus, the rectourethral muscle should be managed carefully regardless of the prostatectomy technique to prevent cavernous nerve injury. 10 The above observations have led to various refinements and modifications to achieve higher standards of efficacy. 3,11-14 The introduction of the intrafascial nerve-sparing procedure proposed the preservation of the periprostatic fascia and nerves by 2010 Elsevier Inc /10/$ All Rights Reserved doi: /j.urology

2 dissecting even closer to the prostate. 6 Preservation of these nerves is thought not only to affect potency but also to improve continence. 2,13-15 Nevertheless, there is a remaining question regarding the benefit of intrafascial procedure compared with the standard (interfascial) nerve sparing. We have previously presented our experience with intrafascial nerve-sparing EERPE (nseerpe) in a series of 150 cases. Erectile function sufficient for intercourse with or without the use of phosphodiesterase-5 (PDE-5) inhibitors was observed in 89.7% of the patients younger than 55 years of age, 81.1% of patients years old, and 61.9% of patients older than 65 at 12 months postoperatively. 3 In the current study, we compare the efficacy and results of the intrafascial nseerpe with the interfascial nseerpe in an attempt to elucidate which technique provides the better outcome. MATERIAL AND METHODS In total, 400 patients underwent bilateral nseerpe between June 2004 and June Two hundred patients were treated with bilateral intrafascial (group A) and 200 with bilateral standard (interfascial) nseerpe (group B). The currently presented cases are consecutive procedures performed with 1:1 randomization of the patients in the above groups. All surgeons performing the current series of procedures had performed several hundred EERPEs each. The EERPE procedure is the standard of care for localized prostate cancer in our institutions. Nevertheless, the nseerpe was performed under specific indications at our institutions. Tumor stages of T1 and T2a, well as serum prostate-specific antigen (PSA) level 10 ng/ml were appropriate. Patients with maximal Gleason score 3 4 (not 4 3) were also candidates for bilateral nseerpe. Preoperative potency is a prerequisite for nseerpe. The techniques of standard and intrafascial nseerpe have been previously reported in detail. 3,7 No posterior bladder neck reconstruction took place in the current groups. The operative time, transfusion rate, conversion rate, catheterization time, pathologic results, positive surgical margin rate, incidence of complications, and requirement of additional interventions were reviewed. Complications and reinterventions encountered during the follow-up period were classified according to the Clavien classification. Pre- and postoperative evaluation of continence and potency for all patients was performed by the use of International Continence Society (ICS) questionnaire and the International Index of Erectile Function (IIEF) along with Sexual Encounter Profile (SEP) diaries, respectively. Potency and continence data were recorded at 6 and 12 months, as well as 3, 6, and 12 months after the procedure, respectively. Patients not requiring any pads or those who did require 1 pad for safety were defined as continent. Requirement for 2-3 pads daily in patients with normal physical activity (walking) was considered as mild incontinence (stress incontinence) and more than 3 pads daily as incontinence. Patients responding positively to the following SEP diary questions: SEP2 Were you able to insert your penis into your partner s vagina? ; SEP3 Did your erections last long enough to have sexual intercourse? ; and SEP5 Were you satisfied with this sexual experience? were defined as potent regardless of the use or not of PDE-5 inhibitors. Cystography was performed 5 days postoperatively and, if satisfactory, the catheter was removed. In case of leakage from the anastomosis, the catheter remained in place for an additional 5-10 days and the cystogram was repeated. Observed differences in potency and continence between the 2 groups were tested for significance using the Fisher s exact test in cases of 1 degree of freedom, for example, when the corresponding contingency tables were 2 2, and chi-square test otherwise. Significance level was set to RESULTS The perioperative patient data of the 2 groups are summarized in Table 1. Similar perioperative data have been observed in both groups except for the pt3 stage, which was more frequent in group B. Conversion to open surgery never took place. Prolonged catheterization for more than 14 days was necessary in 0.5% and 3% for groups A and group B, respectively. Complications occurring in the study groups are presented in Table 2. Continence Continence results of each group are demonstrated in Table 3. Patients of group A reported to be continent (0-1 pads/day) in 74% of the cases at 3 months, whereas 22% reported minimal stress incontinence (2-3 pads/ day), and 4% required 3 pads/day during the same time period. The respective figures for group B were 63%, 22.5%, and 14.5%. At 6 months, 87.9% of group A and 76.2% of group B was continent. Mild stress incontinence was observed in 11.2% and 19.6% of group A and group B, respectively. Incontinent patients represented 0.9% and 4.2% of the respective groups at 6 months. Statistical significance regarding continence was observed between the 2 groups at 3 and 6 months. Continence at 12 months postoperatively was higher with the intrafascial approach (93.2% for group A, 90.7% for group B). No statistical significance was observed between the 2 groups at 12 months. Potency Erectile function sufficient for intercourse with or without the help of PDE-5 inhibitors was reported in 64.8% and 82.8% of group A patients at 6 and 12 months, respectively. The respective figures for group B were 51.4% and 64.8%. Potency results are stratified for age in Table 4. An association between patient age and postoperative erectile function is present. Younger men consistently do better in retaining their erections postoperatively across all groups. The statistical analysis of the potency results revealed significant improved overall potency in the intrafascial group compared with the interfascial group at 12 months (P.005). The comparison of patients from each group according to their age revealed that statistically significant postoperative potency in favor of intrafascial technique was observed in patients 55 years of age at 12 months (P.045). Moreover, significantly better potency was reported by patients years old (P.038) in group A compared with 744 UROLOGY 76 (3), 2010

3 Table 1. Perioperative data Intrafascial (bilateral) Interfascial (bilateral) Patient numbers Age 60 (41-73) 62 (41-75) (M-W U test) Age distribution 55 y: 42 (21%) 55 y: 43 (21%) (z test) y: 108 (54%) y: 113 (54%) (z test) 65 y: 50 (25%) 65 y: 44 (25%) (z test) PSA 6 (1.0-31) 6.8 (0.6-24) (M-W U test) Operative time 140 min (70-280) 135 min (50-250) (M-W U test) Blood loss 200 ml ( ) 200 ml (20-800) (M-W U test) Transfusion rates 0.50% (1/200) 1.00% (2/200) (z test) Size of prostate 40 g (20-105) 44.5 g (16-166) (M-W U test) Duration of catheterization 6 d (5-20) 5 d (3-20) (M-W U test) Catheterization 14 d 0.50% (1/200) 3.00% (6/200) (z test) Gleason-score 4-6: 51.5% (102/198) 45.9% (84/183) (z test) Gleason-score7: 24.5% (49/198) 30.1% (55/183) (z test) Gleason-score: % (47/198) 24.0% (44/183) (z test) pt stage presence in each group pt2: 89% (178/200) pt2: 81% (162/200) (z test) pt3: 11% (22/200) pt3: 19% (38/200) pt2a 14.5% (29/200) 13.5% (27/200) (z test) pt2b 4.0% (8/200) 4.5% (9/200) (z test) pt2c 70.5% (141/200) 63% (126/200) (z test) pt3a 9% (18/200) 16.5% (33/200)) (z test) pt3b 2.0% (4/200) 2.5% (5/200) (z test) Median values are presented. Table 2. Complications of the groups of the study classified according to Clavien Clavien Grade, Complication Intraoperative None Early complications ( 1 month) I urinary retention 1 (prolonged catheterization for 5 days to week)* 6(5 prolonged cathersisation, 1 suprapubic catheter) I d asymptomatic lymphocele 2 (conservative) 1 (conservative) II wound infection II Urinary tract infection 1 (conservative, antibiotics) II deep vein thrombosis 1 (lower limb, conservative) II preperitoneal hematoma None 3 (1 conservative, 2 puncture) (pelvic, paravesical) IIIa,IIIb symptomatic lymphocele 1 (failed puncture and lap. 4(1 puncture, 3 fenestration) fenestration) IIIb gross hematuria 1 (bladder tamponade-conservative) 1 (bladder tamponade-conservative) IIIb bleeding/hematoma 2 (2 open revision- 1perforation of 3 (All. lap revisions) iliac vein due to PLND) IVa incontinence 1 (artificial sphincter implantation) Late complications ( 1 month) None * Management of complications is presented in brackets. their counterparts in group B at 6 and 12 months postoperatively (Table 3). Oncological Results The histologic results are presented in Table 1. Statistically significant higher incidence of pt3 disease was observed in group B. Overall positive surgical margin (PSM) rates were 9% and 9.5% for groups A and B, respectively. At 12 months, the PSA recurrence-free rates were 87.8% for group A and 93.9% for group B (Table 4). COMMENT Further evidence of the anatomy of the pelvic fascia and NVBs has allowed the refinement of nerve-sparing techniques during radical proststectomy. 5-9 However, the role of the lateral nerves in continence or erectile function is unclear. The preservation of the neural tissue situated between the peri-prostatic fascia and the endopelvic fascia has been proposed as a method to improve functional outcome of EERPE and LRP. 3 A recent histopathological study revealed that the posterolateral nerves (NVBs) were supplemented by additional nerves in the anterior midpart and in high density at the posterior surface of the prostate apex. Even if the function of these nerves has not been clarified, the authors suggest that additional nerve fiber preservation would be useful. 16 More recently, an electrophysiological study on the fascias covering the prostate revealed that stimulation of fascia on the ven- UROLOGY 76 (3),

4 Table 3. Postoperative continence and potency rates (functional outcome) Continence Pad Usage Intrafascial (bilateral) Interfascial (bilateral) 2 Test (P values) 3 mo 0-1 pads 74% (128/173) 63% (109/173) pads 22% (38/173) 22.5% (39/173) 3 pads 4% (7/173) 14.5% (25/173) 6 mo 0-1 pads 87.9% (94/107) 76.2% (128/168) pads 11.2% (12/107) 19.6% (33/168) 3 pads 0.9% (1/107) 4.2% (7/168) 12 mo 0-1 pads 93.2% (137/147) 90.7% (68/75) pads 6.1% (9/147) 8.0% (6/75) 3 pads 0.7% (1/147) 1.3% (1/75) Potency Age Intrafascial (bilateral) Interfascial (bilateral) Fisher s Exact Test (P values) 6 mo Overall 64.8% (61/94) 51.4% (37/72) y 81.3% (13/16) 66.7% (18/27) y 67.3% (35/52) 44.1% (15/34) y 46.2% (12/26) 36.4% (4/11) mo Overall 82.8% (82/99) 64.8% (49/77) y 93.5% (29/31) 77.1% (22/30) y 83.3% (40/48) 50% (20/33) y 60.0% (12/20) 40% (7/14).728 Table 4. Oncological outcome: positive surgical margin rates, biochemical free status Intrafascial (bilateral) Interfascial (bilateral) Positive surgical margin Overall 9% 9.5% pt2 6.2% 5.6% pt2a 6.9% 3.7% pt2b 12.5% 11.1% pt2c 5.7% 5.6% pt3 31.8% 26.3% pt3a 33.3% 27.3% pt3b 25% 20% Biochemical free status PSA 0.1 ng/ml 6 mo p.o. 95.2% 96.9% 12 mo p.o. 87.8% 93.9% trolateral sides of the prostate induces an increase in intracavernosal body pressure. Thus, the hypothesis that intrafascial nseerpe preserves neural tissue, which is useful for erectile function, was documented. 17 Nevertheless, concerns of improving functional outcomes at the expense of cancer control have been expressed. The current study provides a direct comparison of patients undergoing an intrafascial procedure with those having an interfascial nseerpe and evaluates the impact of the nerve-sparing procedure in functional and oncological outcome. Several groups have modified their radical prostatectomy techniques to preserve as many nerve fibers as possible. Montorsi et al proposed the incision of levator and prostatic fasciae high ventrally and observed improved postoperative potency. 18 Moreover, Graefen et al recommended the initiation of incision of periprostatic fascia high up the ventral aspect of the prostate. Their results demonstrated correlation between an increased number of preserved nerve fibers and increased erectile function. 19 Savera et al reported improved potency outcomes after the performance of the Veil of Aphrodite RALP (VARALP) technique. The latter technical modification preserves ventrolateral periprostatic fascia. 10 Moreover, Menon et al observed higher potency rates in patients who underwent incision of the prostatic fascia anteriorly. 13 The significantly improved continence at 3 and 6 months after the intrafascial procedure may indicate an advantage of the procedure in early postoperative continence because a statistically significant advantage of intrafascial technique over interfascial was observed at 3 and 6 months postoperatively. Guilloneau et al and Türk et al reported complete continence rates of 76% and 86% at 6 months, respectively. 20,21 Remzi et al prospectively compared laparoscopic extraperitoneal to transperitoneal radical prostatectomy, and open retropubic radical prostatectomy (RRP) and observed full continence in 88%, 85%, and 81% of the patients at 12-month follow-up, respectively (P.2). 22 Mattei et al performed robotic tension-free radical prostatectomy and revealed that 1 week after catheter removal, early urinary continence was achieved in 80% of patients. Moreover, the 4-month follow-up revealed that 92.4% of the patients were continent, 5.4% used 1 pad per day, and 2.2% used 2 or more pads per day. 14 Potency rates reveal a significant better potency for group A (82.8% potent) compared with group B (64.8% potent, P.06) at 12 months. Similar significantly better potency in patients of years of age has been observed (P.038) at 6 and 12-month followup. It should be noted that potency was defined according 746 UROLOGY 76 (3), 2010

5 to validated questionnaires, such as SEP diaries. IIEF questionnaires were also used for the general evaluation of erectile function. SEP diaries results have been observed to possess a high degree of correlation to the IIEF results. 23 Potency with or without the use of PDE5 inhibitors in younger men undergoing unilateral or bilateral nerve-sparing open RRP have been observed to reach up to 86% at 12 months. 4,19,22,24-26 Anastasiadis et al observed 30% and 41% of the patients undergoing LRP (n 230) and RRP (n 70) to be potent at 12 months, respectively. When unilateral or bilateral preservation of the NVBs took place, the potency rates increased from 37% to 44% for RRP and from 46% to 53% for the LRP, respectively. Patients younger than 60 years who underwent bilateral NVB preservation reported potency in 72% and 81% of the cases, respectively. 27 Bilateral nerve-sparing RRP (Graefen et al) in men 55 years, men years, and men 65 years revealed potency rates of 96.5%, 90.7%, and 84.3%, respectively, at 12 months, whereas rates of intercourse were 69.0%, 52.8%, and 37.3%, respectively. 19 Savera et al reported 96% of 154 patients treated by VARALP were able to have intercourse at 1 year. Recovery to normal erectile function was reported by 71% of the patients. 11 The oncological outcome, considering the presence of PSMs, was similar between the 2 groups. The PSM rates for groups A and B were 9% and 9.5% for pt2, respectively. PSMs in groups A and B were observed in 31.8% and 26.3% of the cases. Because the Montsouris Institute reported comparable results for 1000 cases with or without nerve-sparing LRP showing PSMs in 6.9% for pt2a and 34% for pt3b tumors. 28 Touijer et al evaluated the effect of a continuous quality improvement program on the positive surgical margin rate after LRP. The predicted probability for a positive surgical margin decreased from 17.3% for the first patient to 7.5% for the 301st. 29 Similar decrease of PSM rates as experience increased was observed by Atug et al. PSM rates decreased from 45.4% in the first 33 cases to 11.7% in the final 34 cases (total 100 cases of RALP). 30 PSMs were not detected in the plane of periprostatic fascia (anterolateral zone). Capsular incision occurred in 6.6% of the cases was reported by Savera et al. 11 Van der Poel et al retrospectively compared the influence of the extent of fascia preservation to postoperative erectile function. One-hundred-seven patients underwent intrafascial and interfascial nervesparing RALP. They observed that patients who underwent bilateral increased fascia preservation and intrafascial dissection were more likely to have normal erections. Moreover, the potency results tended to be better in the younger patients. At 6 months postoperatively, 53% of the patients reported to have little or no erectile function. PSM rate was 25% in the patients who underwent bilateral nerve sparing and had normal erectile function preoperatively. The authors concluded that intrafascial tumor growth is a contraindication for intrafascial procedure. 31 Patients with pt3 disease were more frequent in group B. Thus, the oncological outcome should be carefully interpreted considering several factors. The diagnosis of pt3 prostate cancer can only be made if the periprostatic fascia is attached to the prostatic histologic specimen. In the intrafascial nseerpe procedure, the periprostatic fascia is preserved and the diagnosis of PSM on the periprostatic fascia is not possible. 9 The higher incidence of pt3 disease could be attributed to the above issues because no selection of patients between the 2 groups took place. Nevertheless, PSMs in pt3 patients that underwent intrafascial procedure was 31.8%. The PSMs could be related to areas other than the periprostatic fascia. In addition, it is not uncommon for the tumor to breach the prostatic capsule toward the periprostatic fascia in some sites, thus the preserved patches of the fascia in the examined prostate help the pathologist to identify PSMs. Martinez-Pineiro suggested that most patients found to have pt3 disease during intrafascial dissection have established extracapsular extension and not focal extension. 9 Secin et al. suggest that the PSM rate is higher in those patients where excessive peeling of the periprostatic fascia has occurred. This is often performed in the posterior dissection where they found the highest PSM in pt3 patients. 32 Moreover, the extent of PSMs has been proposed as an independent factor for biochemical recurrence. 33 In the current study, the biochemical recurrence rates were similar, leading to the assumption that any differences in pt3 stage and detection of PSMs does not influence the oncological outcome of presented techniques, at least during the first year of follow-up. Longer follow-up periods would elucidate any oncological advantage or disadvantage of the NVB preservation approaches. Limitations of the current randomized prospective study represent the limited follow-up of the patients regarding the oncological outcome. A follow-up period of 12 months provides important data but remains inconclusive. Thus, the oncological results do not clarify the impact of the dissection technique. Longer follow-up time would provide solid data on the issue. Although the functional outcome was evaluated by validated questionnaires, continence was not assessed by the most appropriate method, which is the pad-weighting test. Current literature on radical prostatectomy lacks evidence based on the pad-weighting test and consensus regarding the definition of continence. 1 The comparative assessment of 2 NVB dissection techniques in a randomized prospective study using the same tools for evaluation (validated questionnaires) provide additional integrity to the currently presented results despite the absence of a pad-weighting test. In addition, the inclusion of a higher number of patients would have allowed us to provide even more solid comparative data of the 2 techniques, and the current statistical analysis, although conclusive, could have been more accurate. UROLOGY 76 (3),

6 In general, several technical issues should be considered during the performance of a nerve-sparing prostatectomy. A combination of sharp and blunt dissection should be used to mobilize the attachments of the prostate within the periprostatic fascia. The use of energy-producing instruments should be avoided during the preservation of NVBs, periprostatic fascia, and dissection of prostatic pedicles. Proper patient selection should be performed to achieve lower PSMs. In T3 disease, it is more likely that the periprostatic fascia is involved by disease and more adherent to the prostate. If the dissection of the intrafascial plane is not possible because of adherent planes, then a standard nseerpe is advisable. CONCLUSIONS The preservation of additional neural tissue located in the periprostatic fascia as performed in intrafascial nseerpe is associated with significantly better functional outcome. Intrafascial nseerpe provides significantly better potency in patients 55 years of age at 12 months and in patients years of age at 6 and 12 months, with probably limited effect on the radical nature of the surgery. Moreover, the intrafascial technique further decreases procedure-related morbidity by improving the overall postoperative functional outcome. Nevertheless, further clinical investigations are deemed necessary to elucidate the impact of the dissection technique to the oncological outcome. References 1. Ficarra V, Novara G, Artibani W, et al. Retropubic, laparoscopic and robot-assisted radical prostatectomy: A systematic review and cumulative analysis of comparative studies. Eur Urol. 2009;55(5: [ /j.eururo ]. 2. Stolzenburg JU, Kallidonis P, Do M, et al. Endoscopic extraperitoneal radical prostatectomy: evolution of the technique and experience with 2400 cases. J Endourol. 2009;23(9): Stolzenburg JU, Rabenalt R, Do M, et al. Intrafascial nerve-sparing endoscopic extraperitoneal radical prostatectomy. Eur Urol. 2008; 53: Walsh PC. Radical prostatectomy for localized prostate cancer provides durable cancer control with excellent quality of life: a structured debate. J Urol. 2002;163(6): Costello AJ, Brooks M, Cole OJ. Anatomical studies of the neurovascular bundle and cavernosal nerves. BJU Int. 2004;94: Kiyoshima K, Yokomizo A, Yoshida T, et al. Anatomical features of periprostatic tissue and its surroundings: a histological analysis of 79 radical retropubic prostatectomy specimens. Jpn J Clin Oncol. 2004; 34: Stolzenburg JU, Schwalenberg T, Horn L-C, et al. Anatomical landmarks of radical prostatectomy. Eur Urol. 2007;51: Ganzer R, Blana A, Gaumann A, et al. Topographical anatomy of periprostatic and capsular nerves: quantification and computerised planimetry. Eur Urol. 2008;54(2): Martinez-Pineiro L. Prostatic fascial anatomy and positive surgical margins in laparoscopic radical prostatectomy. Eur Urol. 2007;51: Takenaka A, Murakami G, Matsubara A, et al. Variation in course of cavernous nerve with special reference to details of topographic relationships near prostatic apex: histologic study using male cadavers. Urology. 2005;65(1): Savera A, Kaul S, Badani K, et al. Robotic radical prostatectomy with the veil of Aphrodite technique: histological evidence of enhanced nerve sparing. Eur Urol. 2006;49: Curto F, Benijts J, Pansodoro A, et al. Nerve sparing laparoscopic radical prostatectomy: our technique. Eur Urol. 2006;49: Menon M, Shrivastava A, Kaul S, et al. Vattikuti Institute prostatectomy: contemporary technique and analysis of results. Eur Urol. 2007;51: Mattei A, Naspro R, Annino F, et al. Tension and energy free robotic-assisted laparoscopic radical prostatectomy with intrafascial dissection of the neurovascular bundles. Eur Urol. 2007;52: Vallancien G, Cathelineau X, Baumert H, et al. Complications of transperitoneal laparoscopic surgery in urology: review of 1,311 procedures at a single center. J Urol. 2002;168: Sievert K-D, Hennenlotter J, Laible I, et al. The peri-prostatic autonomic nerves-bundle or layer? Eur Urol. 2008;54: Kaiho Y, Nakagawa H, Saito H, et al. Nerves at the ventral prostatic capsule contribute to erectile function: initial electrophysiological assessment in humans. Eur Urol. 2009;55: Montorsi F, Salonia A, Suardi N, et al. Improving the preservation of the urethral sphincter and neurovascular bundles during open radical retropubic prostatectomy. Eur Urol. 2005;48: Graefen M, Walz J, Huland H. Open retropubic nerve-sparing radical prostatectomy. Eur Urol. 2006;49: Guillonneau B, Rozet F, Barret E, et al. Laparoscopic radical prostatectomy: assessment after 240 procedures. Urol Clin North Am. 2001;28: Türk I, Deger IS, Winkelmann B, et al. Laparoscopic radical prostatectomy. Experience with 145 interventions. Eur Urol. 2001; 40(1): Remzi M, Klinger HC, Tinzl MV, et al. Morbidity of laparoscopic extraperitoneal versus transperitoneal radical prostatectomy versus open retropubic radical prostatectomy. Eur Urol. 2005;48(1): Rosen RC. Measurement of male and female sexual dysfunction. Curr Psychiatry Rep. 2001;3: Noldus J, Michl U, Graefen M, et al. Patient-reported sexual function after nerve-sparing retropubic radical prostatectomy. Eur Urol. 2002;42: Kundu SD, Roehl KA, Eggener SE, et al. Potency, continence and complications in 3477 consecutive radical retropubic prostatectomies. J Urol. 2004;172: Barre C. Open radical retropubic prostatectomy. Eur Urol. 2007; 52(1): Anastasiadis AG, Salomon L, Katz R, et al. Radical retropubic versus laparoscopic prostatectomy a prospective comparison of functional outcome. Urology. 2003;62: Guillonneau B, El-Fettouh H, Baumert H, et al. Laparoscopic radical prostatectomy: oncological evaluation after 1,000 cases at Montsouris Institute. J Urol. 2003;169(4): Touijer K, Kuroiwa K, Vickers A, et al. Impact of a multidisciplinary continuous quality improvement program on the positive surgical margin rate after laparoscopic radical prostatectomy. Eur Urol. 2006;49(5): Atug F, Castle EP, Srivastav SK, et al. Positive surgical margins in robotic-assisted radical prostatectomy: impact of learning curve on oncologic outcomes. Eur Urol. 2006;49: Van der Poel HG, de Blok W. Role of extent of fascia preservation and erectile function after robot-assisted laparoscopic prostatectomy. Urology [ /j.urology ]. 32. Secin F, Serio A, Bianco F, et al. Preoperative and intraoperative risk factors for side-specific positive surgical margins in laparoscopic radical prostatectomy for prostate cancer. Eur Urol. 2007;51: Shikanov S, Song J, Royce C, et al. Length of positive surgical margin after radical prostatectomy as a predictor of biochemical recurrence. Urology. 2009;182(1): UROLOGY 76 (3), 2010