## 4 Discussion  
Conserving urinary control without compromising oncological safety is one of the key problems of RP. According to different authors, the continence rate after RP varies between 85% and 100% [13]. In order to improve the post-prostatectomy recovery of continence, numerous surgical method improvements have been developed due to a deeper understanding of the anatomical structures of the pelvis. These include maintaining the length of the urethra, conserving the puboprostatic ligaments and the posterior rhabdomy, and maintaining the bladder neck [13, 14]. Figure 1: Kaplan–Meier survival curve showing the BCR-free rates according to BNP. \begin{table}
\begin{tabular}{c c c c} \hline \hline  & **PSM** & **Non-PSM** & \(p\)**-Value** \\ \hline
**Age (years), mean (SD)** & 65.8 \(\pm\) 4.94 & 65.6 \(\pm\) 5.13 & 0.819 \\
**Preoperative-PSA** & 14.2 (4.59–53.5) & 8.9 (2.47–35.0) & **<0.0001** \\ \hline
**Bioptic Gleason score:** & & & \\
6 (3 + 3) & 9 (21.4\%) & 57 (44.5\%) & \\
7 (3 + 4) & 20 (47.6\%) & 47 (36.7\%) & **0.007** \\
7 (4 + 3) & 9 (21.4\%) & 18 (14.1\%) & \\
8 (4 + 4) & 4 (9.5\%) & 6 (4.7\%) & \\ \hline
**Clinical stage of disease:** & & & \\ T1c & 1 (2.4\%) & 14 (10.9\%) & \\ T2a & 12 (28.6\%) & 67 (52.3\%) & **<0.0001** \\ T2b & 20 (47.6\%) & 32 (25.0\%) & **<0.0001** \\ T2c & 6 (14.3\%) & 12 (9.4\%) & \\ T3a & 3(7.1\%) & 3 (2.3\%) & \\ \hline \hline \multicolumn{4}{c}{**Final pathological stage of disease:**} \\ \multicolumn{1}{c}{pT1} & 0 (0.0\%) & 3 (2.4\%) & \\ \multicolumn{1}{c}{pT2} & 12 (28.6\%) & 103 (80.5\%) & **<0.0001** \\ \multicolumn{1}{c}{pT3} & 29 (69.0\%) & 22(17.2\%) & \\ \multicolumn{1}{c}{pT4} & 1 (2.4\%) & 0 (0.0\%) & \\ \hline \multicolumn{4}{c}{**Operation technique:**} \\ \multicolumn{1}{c}{LRP} & 29 (69.0\%) & 78 (60.9\%) & \\ \multicolumn{1}{c}{ORP} & 13 (31.0\%) & 50 (39.1\%) & 0.345 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Clinico-pathological parameters and surgical margin status—Demographic and clinical data. [PERSON] introduced BNP in 1992 [6]. This procedure was established as a result of a better understanding of the complexity of the urethral sphincter's anatomy. The inner lissosphincter, made of smooth muscle, and the outer rhabdomymeter, composed of skeletal muscle, constitute the urethral sphincter. [PERSON] claims that the rhabdomymeter coats the urethra under stress and circumstances of heightened intra-abdominal pressure, while the lissosphincter is in charge of maintaining baseline and resting continence [15]. The aim of BNP is to maintain the lissosphincter mechanism intact by the dissection and preservation of the circular bladder neck fibers from the base of the prostate. Keeping these fibers makes it possible to directly anastomose the urethral stump and bladder neck circumference without the requirement for bladder neck reconstruction [6,16]. One meta-analysis and two systematic reviews confirmed that BNP is associated with statistically significant improvement in early and long-term continence rate, with lower rates of anastomotic stricture compared to the non-BNP patients [6,17,18]. The main focus of our study was not continence recovery but surgical and pathological outcomes of BNP in LRP and ORP. The potential risk of BNP is an investigated but very controversial theme. Sparing of the bladder neck during surgery can be associated with a higher risk of PSM as a consequence of the potentially incomplete tumor excision. Some authors state that BNP may increase the number of PSM, especially at the base of the prostate. [PERSON] et al. evaluated the rates of PSM following RRP in the group of patients who had undergone bladder neck resection and BNP in a randomized prospective study with a targeted recruitment of 120 participants. Of patients in the preservation group, 10% had PSM, which were exclusively seen at the bladder neck, whereas there were none in the resection group. Due to this finding, the study was discontinued after the enrollment of 70 patients [9].