UroToday.com – In the past it has been suggested that the use of robot assisted laparoscopic radical prostatectomy (RALP) could be associated with a significant and swift reduction in positive surgical margins (PSM) rates. This hypothesis was suggested as it was reasonable to think that an optical magnification, a stereoscopic visualization of tissue planes and accurate anatomical dissection following natural planes could help to obtain a most careful surgical dissection.

Nevertheless, data coming from comparative studies published in literature did not demonstrate any significant advantage of RALP in comparison to traditional laparoscopic radical prostatectomy (LRP) and retropubic radical prostatectomy (RRP) [1]. This lack of an overt superiority of one technique over the others may be the consequence of a lack of an adequate statistical power in making the comparison rather than a real equality between treatments [2].

The authors collected 37 comparative studies by a literature search including a single, randomised, controlled trial. With regard to the perioperative outcome, LRP and RALP were more time consuming than RRP, while blood loss, transfusion rates, catheterisation time, hospitalization duration, and complication rates all favoured LRP.

With regard to the functional results, LRP versus RRP, and LRP versus RALP showed similar continence and potency rates, while a single, nonrandomised, prospective study suggested advantages in terms of both continence and potency recovery after RALP, compared with RRP. With regard to the oncologic outcome, LRP and RALP were associated with positive surgical margin rates similar to those of RRP, hence the conclusion of this review was that the available data were not sufficient to prove the superiority of any surgical approach in terms of functional and oncologic outcomes [1].

In a more recent review on positive surgical margins rate due to RRP, LRP and RALP, 35 manuscripts reporting clinical, pathologic, and/or follow-up data were identified and collected. An overall analysis demonstrated as positive surgical margin rates decreased with the surgeon’s experience and technique improving, reaching percentages similar to those of retropubic and laparoscopic series, ranging from 5% to 27% in pT2 cancers and from 26% to 67% in pT3 cancers [3].

Interestingly, in our series the posterior location was the most common site of positive surgical margins [4], while data from the series of RRP showed the prostatic apex to be the most common site [5, 6]. The available data from RALP series are limited in number and conflicting in content. Smith et al. reconfirmed in their large series of RALPs that PSMs were most commonly found at the apex (12%), followed by posterior (5.5%) and anterior (3%) sites, and concluded that in the hands of surgeons experienced in RALP and RRP, there was a statistically significant lower positive margin rate for patients undergoing RALP [5]. In contrast with these data, some authors found posterolateral PSMs in 12.3% of cases and PSMs at the apex in 5%, data similar to those we presented in our study [7].

Regardless of the approach used to perform radical prostatectomy, factors such as surgeon experience and nerve sparing technique could negatively affect positive surgical margins rates [8]. In particular, the wide spread of robot assisted radical prostatectomy was followed by an increasing application of nerve sparing techniques, preserving the lateral pelvic fascia using the so-called intrafascial plane of surgical dissection [9]. This technical approach could be somehow correlated with an increasing risk of positive surgical margins, although data on this issue were in contrast.

While Kaul et al. reported that preservation of the prostatic fascia is safe and feasible, without compromising the surgical margins, and allows enhanced preservation of neural tissue during robotic prostatectomy with an apparent improvement in potency [9], Liss et al. reported that nerve sparing surgical procedures increase the rates of PSM in extraprostatic prostate cancer [10].

Zorn et al. confirmed that planning side-specific nerve preservation during RALP,according to selected preoperative variables can significantly reduce overall and posterolateral PSM rates [7].

In our series, the 13% PSM rate observed in pT2 cases with a nerve sparing technique was comparable to the 15% recently reported in a large series of consecutive cases treated with interfascial RALP by Zorn et al. [7].

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):1037-1063.
[2] Boscolo-Berto R. [Clinical testing and evidence-based medicine: when the absence of evidence doesn’t mean evidence of absence]. G Ital Nefrol. 2009:26(4):417.
[3] Ficarra V, Cavalleri S, Novara G, Aragona M, Artibani W. Evidence from robot-assisted laparoscopic radical prostatectomy: a systematic review. Eur Urol. 2007:51(1):45-55; discussion 56.
[4] Ficarra V, Novara G, Secco S, et al. Predictors of positive surgical margins after laparoscopic robot assisted radical prostatectomy. J Urol. 2009:182(6):2682-2688.
[5] Smith JA, Jr., Chan RC, Chang SS, et al. A comparison of the incidence and location of positive surgical margins in robotic assisted laparoscopic radical prostatectomy and open retropubic radical prostatectomy. J Urol. 2007:178(6):2385-2389; discussion 2389-2390.
[6] Sofer M, Hamilton-Nelson KL, Civantos F, Soloway MS. Positive surgical margins after radical retropubic prostatectomy: the influence of site and number on progression. J Urol. 2002:167(6):2453-2456.
[7] Zorn KC, Gofrit ON, Steinberg GP, et al. Planned nerve preservation to reduce positive surgical margins during robot-assisted laparoscopic radical prostatectomy. J Endourol. 2008:22(6):1303-1309.
[8] Yossepowitch O, Bjartell A, Eastham JA, et al. Positive surgical margins in radical prostatectomy: outlining the problem and its long-term consequences. Eur Urol. 2009:55(1):87-99.
[9] Kaul S, Bhandari A, Hemal A, et al. Robotic radical prostatectomy with preservation of the prostatic fascia: a feasibility study. Urology. 2005:66(6):1261-1265.
[10] Liss M, Osann K, Ornstein D. Positive surgical margins during robotic radical prostatectomy: a contemporary analysis of risk factors. BJU Int. 2008:102(5):603-608.

Written by Rafael Boscolo-Berto, MD as part of Beyond the Abstract on UroToday.com. This initiative offers a method of publishing for the professional urology community. Authors are given an opportunity to expand on the circumstances, limitations, etc., of their research by referencing the published abstract.

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