Intrafascial nerve-sparing Laproscopic Radical Prostatectomy: Do we really preserve relevant nerve-fibres?

Oncological safety of intrafascial nerve-sparing radical prostatectomy compared with conventional process: a pooled review and meta-regression analysis based on available studies

Background

Intrafascial prostatectomy was a modified technique from the conventional nerve-sparing surgery in order to improve patients’ post-surgical continence and erectile function; however, ongoing controversy exists regarding the oncological safety of this technique. In this study we aimed to provide a critical and pooled analysis based on published literatures regarding the oncological outcomes after intrafascial nerve-sparing prostatectomy.

Methods

Database searches were performed for published articles till June 2018 on PubMed. Three reviewers screened fulfilled papers and extracted data independently. Main outcome was the positive surgical margins (PSMs) rates stratified by pathological stages. We performed both one-arm and comparative meta-analysis to evaluate the oncological safety of intrafascial technique. Moreover, we built meta-regression models to assess the confounding factors.

Results

We retrieved a total of 117 records after electronic search, of which 21 studies were finally included in this review. There were 15 controlled studies and 6 surgical series. Our one-arm meta-analysis demonstrated that the total PSM rates after intrafascial techniques ranging from 2.2 to 35%, with a pooled rate of 14.5% on average (480 of 3151 patients, 95% confidence interval[CI]: 11.2–17.5%). Meta-regression model showed that patients’ age, pT2 cancer percentage and Selection Score of Oncological Safety (SSOS) were significantly associated with total PSM rate; moreover, each 1 point of SSOS could decrease the total PSM rate by 1.3% on average. Comparative meta-analysis demonstrated that there was no significant difference between intra- and inter-fascial group regarding PSM rates.

Conclusions

With stringent case selection and when performed by experienced surgeons, intrafascial prostatectomy could offer an acceptable or, at least, equivalent PSM rate compared with the conventional interfascial approach. Preoperative SSOS more than 7 points could be considered as an indication of intrafascial radical prostatectomy.

Electronic supplementary material

The online version of this article (10.1186/s12894-019-0476-2) contains supplementary material, which is available to authorized users.

Analysis of a practical surgical skills laboratory for nerve sparing radical prostatectomy

PURPOSE

With the rapidly expanding anatomical and technical knowledge surrounding nervesparing radical prostatectomy (NSRP), anatomical and operative textbooks have failed to keep pace with the literature. A surgical skill laboratory (SSL) was designed to educate urology trainees on surgical anatomy and techniques for NSRP. The objective was to assess the validity of a SSL program.

METHODS

A low-fidelity, anatomically accurate prostate model with its appropriate fascial coverings and location of the neurovascular bundle was created. Participants were surveyed prior to a SSL workshop for their knowledge of NSRP focusing on clinical and anatomical considerations. An interactive 2-h tutorial and workshop was then undertaken outlining the clinical and anatomical nuances for NSRP, with participants then practising an intra and inter-fascial NSRP on the model. Participants were resurveyed immediately after the workshop and at 6 months.

RESULTS

Thirty participants completed the NSRP workshop. Significant differences (p < 0.0001) in anatomical and clinical knowledge were noted after the workshop with improvements for both junior and senior trainees. The knowledge was retained at 6 months following the workshop.

CONCLUSIONS

A low-fidelity bench-top model is a feasible and reproducible technique for improving the understanding of periprostatic anatomy and the different surgical approaches for NSRP. The SSL is useful and knowledge gained appears to be retained by workshop participants. SSL workshops are a valid hands-on approach to teaching surgical skills and should remain an integral part of urology training.

Intrafascial nerve-sparing radical prostatectomy improves patients' postoperative continence recovery and erectile function: A pooled analysis based on available literatures

BACKGROUND

Intrafascial nerve-sparing prostatectomy has been currently applied based on the updated anatomic understanding of periprostatic cavernous nerves, in order to provide patients better postoperative recovery of continence and potency. The aim of our study is to perform a pooled analysis of available literatures regarding the functional outcomes following intrafascial nerve-sparing technique.

METHODS

The authors performed database searches of articles published till October 2017 on PubMed using following keywords across the "title" and "abstract" field of the records: intrafascial, veil, curtain dissection, high anterior release, incremental nerve sparing, and radical prostatectomy. Fulfilled papers were screened and data were extracted independently by 3 reviewers. Main outcome was the postoperative continence and potency rate stratified by follow-up durations. Both 1-arm and comparative meta-analyses were performed and meta-regression models were conducted to evaluate the confounding factors.

RESULTS

Using the electronic search strategy, a total of 71 records were retrieved and 20 studies were finally included, of which 6 were surgical series and 14 were controlled studies. Our 1-arm meta-analysis summarized the pooled continence rates after intrafascial prostatectomy were 59.4%, 76.2%, 89.9%, and 92.2% at postoperative follow-up of 1, 3, 6, and 12 months, respectively. Regardless of the variance in potency definition, the pooled potency rates after intrafascial prostatectomy were 42.2%, 54.2%, and 72.2% at 3, 6, and 12 months, respectively. Comparative analysis showed that the intrafascial group offered better continence rates at 1, 3, and 6 months with an odds ratio (OR) of 2.38 (95% confidence interval [CI]: 1.73-3.26), 1.82 (95% CI: 1.18-2.82), and 2.19 (95% CI: 1.43-3.34) as compared with the interfascial group. Moreover, potency rate in the intrafascial group was higher at 12 months than in the interfascial group, with an OR of 2.44 (95% CI: 1.35-4.42).

CONCLUSION

Based on the limited evidence, our study demonstrated that intrafascial nerve-sparing prostatectomy could provide patients with earlier recovery of continence and better erectile function compared with conventional interfascial approach, but physiological mechanisms about this technique still need further study.

Comparison of intrafascial and non-intrafascial radical prostatectomy for low risk localized prostate cancer

In this meta-analysis study, we compared the oncological and functional outcomes of intrafascial radical prostatectomy (IFRP) with non-intrafascial radical prostatectomy (NIFRP) in the treatment of patients with low risk localized prostate cancer (PCa). Relevant articles were identified by searching PubMed, EMBASE, Cochrane Library, Ovid, and the ISI Web of Knowledge databases. A total of 2096 patients were included from 7 eligible studies. Results of the pooled data showed that the oncological outcomes including gleason score, positive surgical margin and biochemical free survival rates were similar between the two groups. IFRP was superior to NIFRP with lower postoperative complication rates (RR 0.57, 95% CI 0.38, 0.85, p = 0.006), higher continence rates at 3 months post-operation (RR: 1.14; 95% CI, 1.04, 1.26; p = 0.006), and higher potency rates at 6 months (RR: 1.53; 95% CI, 1.07, 2.18; p = 0.02) and 12 months post-operation (RR: 1.38; 95% CI, 1.11, 1.73; p = 0.005). Additionally, there was a tendency towards higher potency rate in patients ≤65 years old compared with patients >65 years old after IFRP. Overall, these findings suggest that IFRP in young patients with low risk localized PCa had less postoperative complications, shortened time to return to continence and improved potency rate without compromising complete tumor control.

Correlation of histomorphologic findings and partial neurovascular bundle preservation during laparoscopic and robotic radical prostatectomy

The objective of this work was to compare the amount of residual periprostatic tissue for radical prostatectomy performed by the partial NS (PNS) technique with that performed by the nerve-sparing (NS) or wide-resection (WR) techniques. Retrospective histomorphologic evaluation of radical prostatectomy specimens (RPSs) from patients undergoing laparoscopic radical prostatectomy (LRP) or robot-assisted radical prostatectomy (RARP) was performed. The posterolateral regions corresponding to the neurovascular bundle in RPSs from 48 patients who had undergone NS, PNS, or WR during LRP (n = 30) or RARP (n = 18) were examined by two pathologists unaware of the technique used. The RPSs were evaluated at the base, mid-gland, and apex. The amount of periprostatic tissue at each site was recorded. Measurements were analyzed by use of a linear mixed model. For both LRP and RARP, each gradation of nerve-preservation was associated with periprostatic tissue, except PNS and WR did not differ for LRP at the apex and base or for RARP at the apex, mid-gland, and base. For LRP, a greater amount of tissue was on the left side of the prostate than on the right at the mid-gland level (P = 0.004) whereas for RARP the opposite was found (P = 0.024). Of 18 separate analyses, 13 were significantly associated. The study is limited by its retrospective design. The amount of periprostatic tissue in the neurovascular bundle area correlates well with the nerve-preservation approach used during LRP and RARP, providing anatomic evidence supporting the PNS approach. We also describe a novel finding of laterality bias at the mid-gland level in LRP and RARP specimens.

Diffusion tensor magnetic resonance tractography of the prostate: feasibility for mapping periprostatic fibers

OBJECTIVE

To evaluate the feasibility of diffusion tensor imaging (DTI) tractography of the prostate for mapping of periprostatic neurovascular anatomy.

METHODS

Eight men with prostate cancer scheduled to undergo nerve-sparing robot-assisted radical prostatectomy (RARP) underwent endorectal multiparametric magnetic resonance imaging (MRI) of the prostate with DTI. Tract mapping was accomplished by positioning spherical regions of interest contiguously along the prostatic capsule at the prostatic apex, midgland, and base.

RESULTS

DTI tractography of the prostate effectively visualized periprostatic fiber tract anatomy. There was no significant correlation between total tract number and prostate size, however (Spearman's coefficient = 0.33, P = .42). Variation in tract distribution existed. The total fiber mass was highest in the lower prostate hemisphere at the base of the prostate (mean = 36.9 vs 21.1, P = .0004) and in the upper hemisphere at the apex (mean = 41.6 vs 57.9, P = .006).

CONCLUSION

DTI tractography successfully visualized fiber tracts around the prostate. Gold standard anatomic correlation is needed.

Surgical anatomy of the prostate in the era of radical robotic prostatectomy

PURPOSE OF REVIEW

New insights in the anatomy of the prostate and the surrounding tissue evolve the technique of radical prostatectomy for the treatment of prostate cancer.

RECENT FINDINGS

Regarding the course of the erectile nerves along the prostate, recent studies confirmed the presence of parasympathetic pro-erectile nerve fibers at the anterolateral aspect of the prostate. Another study of intraoperative electrostimulation of those nerves confirmed an increase in intracavernosal pressure by stimulations between the 1 and 3 o'clock position. Therefore, it is very likely that these anterior nerve fibers have an effect on erectile function. Regarding the urethral sphincter in the male, a study showed no attachment of the external sphincter to the levator ani muscle, probably resulting in an absence of a levator ani support to the continence mechanism. The male urinary sphincter seems to be in isolation responsible for urinary continence.

SUMMARY

The nerve fibers at the anterolateral aspect of the prostate seem to participate in erectile function, which renders the concept of a high anterior release during nerve sparing beneficial. The isolated urinary sphincter mechanism results in the need to conserve as much urethral length as possible during radical prostatectomy to avoid urinary incontinence.

Radical prostatectomy: evolution of surgical technique from the laparoscopic point of view

PURPOSE

To review the literature and present a current picture of the evolution in radical prostatectomy from the laparoscopic point of view.

MATERIALS AND METHODS

We conducted an extensive Medline literature search. Articles obtained regarding laparoscopic radical prostatectomy (LRP) and our experience at Institut Montsouris were used for reassessing anatomical and technical issues in radical prostatectomy.

RESULTS

LRP nuances were reassessed by surgical teams in order to verify possible weaknesses in their performance. Our basic approach was to carefully study the anatomy and pioneer open surgery descriptions in order to standardized and master a technique. The learning curve is presented in terms of an objective evaluation of outcomes for cancer control and functional results. In terms of technique-outcomes, there are several key elements in radical prostatectomy, such as dorsal vein control-apex exposure and nerve sparing with particular implications in oncological and functional results. Major variations among the surgical teams' performance and follow-up prevented objective comparisons in radical prostatectomy. The remarkable evolution of LRP needs to be supported by comprehensive results.

CONCLUSIONS

Radical prostatectomy is a complex surgical operation with difficult objectives. Surgical technique should be standardized in order to allow an adequate and reliable performance in all settings, keeping in mind that cancer control remains the primary objective. Reassessing anatomy and a return to basics in surgical technique is the means to improve outcomes and overcome the difficult task of the learning curve, especially in minimally access urological surgery.

Overcoming the learning curve for robotic-assisted laparoscopic radical prostatectomy

Robotic-assisted laparoscopic radical prostatectomy (RALP) has been rapidly adopted in the last few years despite having a prolonged learning curve. This article describes the RALP learning curve, reviews in detail the challenging steps of the operation, describes the authors' RALP technique, and concludes with tips to overcome the learning curve.

A critical analysis of the current knowledge of surgical anatomy related to optimization of cancer control and preservation of continence and erection in candidates for radical prostatectomy

CONTEXT

Detailed knowledge of the anatomy of the prostate and adjacent tissues is mandatory during radical prostatectomy to ensure reliable oncologic and functional outcomes.

OBJECTIVE

To review critically and to summarize the available literature on surgical anatomy of the prostate and adjacent structures involved in cancer control, erectile function, and urinary continence.

EVIDENCE ACQUISITION

A search of the PubMed database was performed using the keywords radical prostatectomy, anatomy, neurovascular bundle, fascia, pelvis, and sphincter. Relevant articles and textbook chapters were reviewed, analyzed, and summarized.

EVIDENCE SYNTHESIS

Anatomy of the prostate and the adjacent tissues varies substantially. The fascia surrounding the prostate is multilayered, sometimes either fused with the prostate capsule or clearly separated from the capsule as a reflection of interindividual variations. The neurovascular bundle (NVB) is situated between the fascial layers covering the prostate. The NVB is composed of numerous nerve fibers superimposed on a scaffold of veins, arteries, and variable amounts of adipose tissue surrounding almost the entire lateral and posterior surfaces of the prostate. The NVB is also in close, cage-like contact to the seminal vesicles. The external urethral sphincter is a complex structure in close anatomic and functional relationship to the pelvic floor, and its fragile innervation is in close association to the prostate apex. Finally, the shape and size of the prostate can significantly modify the anatomy of the NVB, the urethral sphincter, the dorsal vascular complex, and the pubovesical/puboprostatic ligaments.

CONCLUSIONS

The surgical anatomy of the prostate and adjacent tissues involved in radical prostatectomy is complex. Precise knowledge of all relevant anatomic structures facilitates surgical orientation and dissection during radical prostatectomy and ideally translates into both superior rates of cancer control and improved functional outcomes postoperatively.

[Significance of residual hyperplastic cells after radical prostatectomy. A literature review]

INTRODUCTION

Radical prostatectomy represents a standard surgical treatment for clinically localized prostate cancer. Classically pathologist and urologist worried about positive surgical margin, but not to the presence of surgery residual hyperplastic cells able to generate prostate specific antigen (PSA) and difficult the follow up of the patients that underwent surgery. We reviewed the literature looking for the incidence, the potential etiology and the influence of these hyperplastic cells in the biochemical evolution of the disease.

MATERIAL AND METHOD

The information for this review was compiled by searching the Pubmed database. We used "Mesh", Prostatectomy" and "Prostatic Neoplasms" and "Prostate-Specific Antigen" terms, and we added "biochemical failure" and/or "hyperplasic cells" and/or "benign cells". Furthermore, we select the work in English, Spanish and German, review articles that referenced this work and include the series with more than 50 patients, letters to the editor, editorials and overall reviews.

CONCLUSIONS

Benign hyperplasic cells left behind after radical prostatectomy are frequent and probably under-rated. The influence of those cells in the biochemical outcome is a controversial issue. Positive margins for benign cells can come from apex or neck of the bladder, where the prostatic capsule is not well defined, but no from dorso-lateral area, this would imply a technical mistake. We recommend the inspection of the specimen by the surgeon, after prostatectomy in order to detect apex integrity, cranial and dorso-lateral capsule.

Planned nerve preservation to reduce positive surgical margins during robot-assisted laparoscopic radical prostatectomy

PURPOSE

The main objective of radical prostatectomy (RP) is optimal oncologic resection with preservation of sexual function (SF). During our initial experience with robot-assisted laparoscopic radical prostatectomy (RLRP), we noted a high rate of posterolateral location of positive surgical margins (PSM) with nerve preservation (NP). With its magnified view of the surgical field and improved instrument precision, one potential advantage of RLRP is the ability to tailor the degree of NP. We evaluated the effect of a protocol for side-specific NP based on preoperative variables on PSM rates and SF outcomes.

METHODS

Between June and November 2006, 150 consecutive RLRPs were performed using a surgical protocol to select side-specific NP techniques (interfascial [IF], partial extrafascial [pEF], and wide extrafascial resection [WEFR]) based on preoperative risk factors (clinical stage, biopsy Gleason score, percentage of positive cores and maximal core cancer percentage, and preoperative PSA). Pathologic and SF outcomes in these patients were compared with those of a control group of 245 consecutive RLRPs in whom non-selective IF dissection was performed. All data were prospectively collected.

RESULTS

Mean patient age, PSA, clinical stage, biopsy Gleason score and positive core involvement, pathologic Gleason score, and stage were comparable among the two groups. The overall PSM rate (12.6% nu 20.4%; P = 0.04) and posterolateral location of PSMs (37% nu 70%; P = 0.04) were significantly lower in the study group. At 12 months, potency was reported in 80%, 67%, and 11% of men undergoing bilateral IFNP, partial extrafascial nerve preservation (pEFNP), and WEFR, respectively (P = 0.27).

CONCLUSIONS

Planning side-specific NP during RLRP, according to selected preoperative variables, can significantly reduce overall and posterolateral PSM rates. Furthermore, partial nerve sparing (pEFNP) also appears to confer favorable early SF outcomes.

External validation of a nomogram for prediction of side-specific extracapsular extension at robotic radical prostatectomy

BACKGROUND AND PURPOSE

Several staging tools have been developed for open radical prostatectomy (ORP) patients. However, the validity of these tools has never been formally tested in patients treated with robot-assisted laparoscopic radical prostatectomy (RALP). We tested the accuracy of an ORP-derived nomogram in predicting the rate of extracapsular extension (ECE) in a large RALP cohort.

PATIENTS AND METHODS

Serum prostate specific antigen (PSA) and side-specific clinical stage and biopsy Gleason sum information were used in a previously validated nomogram predicting side-specific ECE. The nomogram-derived predictions were compared with the observed rate of ECE, and the accuracy of the predictions was quantified. Each prostate lobe was analyzed independently. As complete data were available for 576 patients, the analyses targeted 1152 prostate lobes. Median age and serum PSA concentration at radical prostatectomy were 60 years and 5.4 ng/mL, respectively.

RESULTS

The majority of side-specific clinical stages were T(1c) (993; 86.2%). Most side-specific biopsy Gleason sums were 6 (572; 49.7%). The median side-specific percentages of positive cores and of cancer were, respectively, 20.0% and 5.0%. At final pathologic review, 107 patients (18.6%) had ECE, and side-specific ECE was present in 117 patients (20.3%). The nomogram was 89% accurate in the RALP cohort v 84% in the previously reported ORP validation.

CONCLUSIONS

The ORP side-specific ECE nomogram is highly accurate in the RALP population, suggesting that predictive and possibly prognostic tools developed in ORP patients may be equally accurate in their RALP counterparts.

Robotic-assisted laparoscopic prostatectomy: functional and pathologic outcomes with interfascial nerve preservation

INTRODUCTION

Robotic-assisted laparoscopic radical prostatectomy (RLRP) is increasingly becoming an alternative to open and laparoscopic radical prostatectomy in the treatment of localized prostate cancer. RLRP has been associated with low morbidity, short convalescence and comparable oncologic and functional outcomes. We report our initial experience of 300 consecutive cases with selective use of interfascial nerve preservation (IFNP).

METHODS

Between February 2003 and September 2005, 300 consecutive men underwent RLRP at our institution. Patients were followed prospectively with validated questionnaires.

RESULTS

Mean operative time was 282 minutes with an estimated blood loss of 273 ml. The intra-operative complication rate was 2.3% with no mortality. Return to baseline (RTB) urinary function and subjective continence at 12 months were 71% and 90.2%, respectively. RTB sexual function and subjective potency at 12 months were 53% and 80.4%, respectively. Overall, the positive surgical margin (PSM) rate was 20.9%: 15.1% for pT2 and 52.1% for pT3 disease and 93.1% had an undetectable PSA (<0.1 ng/mL) with a mean follow-up of 17.3 months. Fifty-four percent of PSMs occured in a poster-lateral (PL) location. Retrospectively, IFNP was performed in 86.5% and 62.5% of pT2 and pT3 PSMs, respectively. Pathologic-T3 PSMs were found to occur significantly more often in a PL location when ipsilateral IFNP was performed when compared to non-IFNP (73% vs 33%, p=0.05).

CONCLUSIONS

IFNP appears to result in favorable return of potency, however, postero-lateral PSMs appear to occur more frequently with this technique. Proper patient selection for robotic surgery and nerve-preservation appears to be critical in order to reduce PSM and optimize the oncologic efficacy of this technology.