 the three goals of radical prostatectomy (  ) are cancer control , preservation of urinary control , and preservation of sexual function. as the techniques of rp have evolved , our understanding of the relevant anatomy has improved and better oncological and functional outcomes have been reported . despite this , there remains no consensus on operative technique and there remain many technical components of the procedure itself where controversy exists .
one such contentious area is the role of bladder neck sparing ( bns ) versus bladder neck reconstruction ( bnr ) and the impact of both techniques on oncological and functional outcomes .
those in favour of bns suggest this technique allows earlier return of continence and a lower incidence of post - operative strictures , without compromising oncological clearance .
surgeons who favour bnr state concerns about compromising surgical margins with no definitive improvement in functional outcome .
bns has been incorporated into open rp ( orp ) , laparoscopic rp ( lrp ) and robot - assisted laparoscopic prostatectomy ( ralp ) techniques .
technical aspects of bns vary between the surgical approaches because of the technical difficulties this can present and the prolonged learning curve .
circumferential , anterior and lateral approaches to the have all been described in orp , lrp and ralp .
improved surgical techniques and appreciation of the local anatomy have seen huge modifications to the technique of rp since the first described procedure by proust in 1901 .
preservation of the neurovascular bundle was first reported in 1983 by walsh et al . and
since then , sparing of suspensory mechanism of the urethra preservation of urethral length posterior rhabdosphincter sparing , bns and seminal vesicle sparing have all been described as important techniques for optimising functional outcome after rp .
bns has evolved from a better understanding of the anatomy and physiology of mechanisms of uc .
new research based on embryological , 3d imaging and urodynamic studies have redefined our understanding of the urinary sphincter mechanism .
we now understand the contributions of the bn as an integral part of larger , complex sphincter mechanism that consists of both striated and smooth muscle fibres , rather than an independent external ( rhabdo ) and internal ( lisso ) sphincter as previously thought .
the rhabdosphincter is horseshoe - shaped and overlies the circular and longitudinal smooth muscle of the urethra . during periods of increased intra - abdominal pressures it contracts and
coapts the urethra . due to the relatively low volume of slow twitch muscle fibres compression of the rhabdosphinter can not be sustained for longer than about 60 s. during the storage phase , the lissosphincter maintains urethral resistance and is the primary mechanism responsible for maintaining resting and baseline continence .
urodynamics studies have demonstrated that an intact lissosphincter maintains continence in the absence of a viable rhabdosphincter .
bns technique aims to leave most of the lissosphincter mechanism intact allowing preservation of its function .
we performed a search of the pubmed , science direct and wiley library databases to identify original and review articles in english which addressed bns and bn reconstruction techniques , oncological and functional outcomes of orp , lrp and ralp , where bns technique was used .
the search terms used were bn , spare , preservation , reconstruction , urinary incontinence , positive margin , orp , lrp and ralp .
relevant articles were reviewed , analyzed and summarized in line with the intentions of this review article .
our initial online database search returned 345 results ; 133 via science direct , 122 via pubmed and 90 via wiley library .
after narrowing the search down to the relevant papers , current review included 12,806 patients in 31 original studies plus further two review articles directly pertinent to the topic of bns and bnr .
there are 19 studies describing outcomes of bns in orp included in the review , six studies on bns in lrp and five original articles on outcomes of bns in ralp .
the only prospective , randomised study included patients undergoing both ralp and orp ( level of evidence 1b ) .
remaining studies are non - randomised prospective and retrospective studies with varying population size sample ( level of evidence 2 - 4 ) .
the relationship between bns and positive surgical margin ( psm ) is well - documented in the literature [ table 1 ] .
however , only one study is a prospective , randomised , blinded study with a control group .
gomez et al . in a prospective study did not find any sole psm at bn in the cohort of 50 men undergoing orp and bns , although there were six patients ( 12% ) who had multiple positive margins involving bn .
wood demonstrated that all nine patients ( 12% ) who had psm at the bn had multiple psm 's and t3 disease .
reported there was no sole psm at bn after orp and 7.5% patients had psm at the bn , which were multiple psm 's .
soloway and neulander found only 1% sole psm at bn . in his study of 676 patients , 4.3% patients had multiple psm also involving bn . in the series of 365 patients undergoing orp shelfo et al . reported total psm rate at 32% , but only two patients had sole bn psm
similarly , poon et al . in the retrospective cohort study of 220 men concluded no statistical difference between patients undergoing bns versus the control group .
as described by bianco et al . in the larger prospective studies of 555 men undergoing orp , total psm was 32% with 13% psm at bn and 0.36% sole psm at bn .
, in a series of 619 men undergoing ralp , assessed psm rate at the base of the prostate in the bns versus control group .
similarly , friedlander et al . in a retrospective evaluation of a large cohort of over 1000 men demonstrated identical psm for bns and control group , which was 13.8% . in a new prospective , randomised , controlled and blinded study from the heidelberg group , only 2% of bns group had a sole psm at the bn compared with 12.5% psm rate in the control group .
published results of their prospective study , where they ceased recruitment after 70 patients as the psm rate was 10% , all being at the bn irrespective of the group . in lrp , katz et al .
published results of the series , where overall psm was 26% and psm at bn as 9.75% . during the study , they abandoned bns approach and decreased psm at bn to zero .
several studies stressed that appropriate patient selection is crucial in order not to compromise the surgical outcome .
oncological outcomes of bns high gleason score on the prostatic biopsies or suspicion of extra - prostatic extension increases the risk of psm at the bn .
aydin et al . described the significance of a sole psm at the bn . in his retrospective study of 164 men with psm after orp , 23% had sole psm at the bn .
those patients had 69.8% 5-year actuarial risk of biochemical progression compared with 33% who had negative bn margin .
the data highlights that the presence of a psm at the bn has a significant impact on long - term outcomes .
both marcovich et al . and aydin et al . have found that a psm at the bn results in higher rates of biochemical recurrence when compared with single or multiple psm at other sites .
however , in 2010 , pierorazio et al . published the results of large review on over 17,000 patients .
patients with an isolated psm at the bn had prostate specific antigen ( psa ) free survival rate of 37% and cancer free survival of 92% , which was comparable to prognosis of patients with a seminal vesicle invasion and an extracapsular extension respectively .
they concluded that american joint committee on cancer should reconsider bn involvement staging as t4 . assessing long - term oncological outcomes
, we were able to identify only four studies where biochemical recurrence - free survival ( bcrfs ) in bns cohorts was compared with non - bns cohort .
friedlander et al . assessed psa , surgical margin status and pathological stage and grade and demonstrated no difference in bcrfs between bns and control groups with a follow - up period of up to 72 months ( hazard ratio 1.20 , 95% confidence interval 0.62 - 2.31 , p = 0.596 ) . similarly , in their prospective , controlled study , bianco et al .
reported that during 7-year of follow - up , bns did not compromise disease free survival ( dfs ) .
univariable and multivariable analyses of psm at bns was not a statistically important factor for dfs .
licht et al . also assessed dfs between bns and non - bns groups and showed no statistical difference .
reported that at 5.2-year follow - up , 90% of bns group had a psa of less than 0.2
mcg / l and 80% of the non - bns group had a psa of less than 0.2
. post - operative return to uc is similar in the reported orp , lrp and ralp series . where the bn was preserved uc varies between 36% and 100% at 1 month and 84% to 100% at 12 months follow - up .
the method of assessment of uc post - rp has always been controversial and there is no consensus definition . in a prospective study lowe defined uc as usage of zero pads per day . in his series ,
uc at 1 month was 23% in the bns group and 11% in the non - bns group were continent , which was statistically significant .
long - term uc was similar , 89% and 86% bns and non - bns cohorts respectively .
studied continence in patients undergoing orp and bladder bnr ( anterior bladder tube reconstruction [ abtr ] vs. tennis racket repair [ trr ] ) .
differences in maximal urethral closing pressures were the only statistically significant findings between both groups post - operatively .
following analysis , preservation of functional urethral length was significantly longer in patients undergoing abtr .
furthermore , poon et al . compared outcomes of bns with abtr and trr . at intervals of 1 week ,
4 weeks , 3 months , 6 months and 12 months there was no statistical difference in uc among those groups .
, however , due to the high prevalence of psm at the bn recruitment to the study was halted pre - maturely .
a significant improvement in uc post - bns was reported by gaker and steel , and deliveliotis et al . in both prospective studies , early return of uc in bns groups
the study of 600 patients undergoing lrp reported a return to uc at 12 months at 84% .
bns was associated with a statistically insignificant faster recovery of uc at 3 months and statistically significant difference in uc at 12 months between bns and non - bns groups , 94.9% and 80.1% , respectively using one pad or less as a definition of continence .
more recently , studies aiming at evaluation of bns technique in ralp have been published .
reported significantly better early uc in bns group versus non - bns group at 65.6% and 26.5% respectively . at 2-year follow - up , there was no statistical difference between bns and non - bns groups and was 100% and 96.1% , respectively . in 2012
, in a large retrospective cohort of 1067 men showed a significant improvement in early uc between bns and control groups particularly at 5 and 12 months follow - up . in another study , you et al .
compared functional outcomes of ralp with bns and bns plus posterior urethral reconstruction ( pur ) ; however , their study was performed retrospectively on a relatively small sample .
nevertheless , it demonstrated a significant improvement in return to uc between a control and pur groups and control and bns - pur groups .
the authors concluded that pur and bns are related with improved uc post - ralp .
the only prospective , randomised , controlled , blinded study comes from the heidelberg group .
84.2% of patients with bns were continent compared with 55.3% in non - bns procedure .
similarly at 12 months , the difference in uc was statistically significant and rates were 94.5% and 81.4% for bns and non - bns groups .
moreover , in the multiple logistic regression analysis bns was an independent positive predictor of uc .
functional outcomes post - bns gomez et al . were reported that neo vesico - urethral anastomosis stricture rate were lower in bns group compared with the non - bns group .
subsequent literature consistently supported these findings and currently there is an agreement that stricture rate post - bns is relatively lower than in patients not undergoing bns .
poon et al . reported bn stricture at 5% for bns and 11 - 18% for bnr techniques .
gaker and steel in 2004 reported that 2.9% of bns patient had an anastomotic stricture .
other studies present similar findings . in 2004 , besarani et al . demonstrated that strictures occur mostly within 3 months post - surgery ( 75% ) and are less frequent after 12 months from surgery ( 5% ) .
more recently , the heidelberg group did not observe the occurrence of any bn strictures post - rp in either bns and control groups .
available evidence suggests that bns technique is likely to be superior to non - bns for preventing anastomotic strictures .
however , most of evidence comes from non - randomised trials hence level of evidence is relatively low .
the relationship between bns and positive surgical margin ( psm ) is well - documented in the literature [ table 1 ] .
however , only one study is a prospective , randomised , blinded study with a control group .
gomez et al . in a prospective study did not find any sole psm at bn in the cohort of 50 men undergoing orp and bns , although there were six patients ( 12% ) who had multiple positive margins involving bn .
wood demonstrated that all nine patients ( 12% ) who had psm at the bn had multiple psm 's and t3 disease .
reported there was no sole psm at bn after orp and 7.5% patients had psm at the bn , which were multiple psm 's .
soloway and neulander found only 1% sole psm at bn . in his study of 676 patients , 4.3% patients had multiple psm also involving bn . in the series of 365 patients undergoing orp shelfo et al .
reported total psm rate at 32% , but only two patients had sole bn psm .
similarly , poon et al . in the retrospective cohort study of 220 men concluded no statistical difference between patients undergoing bns versus the control group .
as described by bianco et al . in the larger prospective studies of 555 men undergoing orp , total psm was 32% with 13% psm at bn and 0.36% sole psm at bn .
, in a series of 619 men undergoing ralp , assessed psm rate at the base of the prostate in the bns versus control group .
similarly , friedlander et al . in a retrospective evaluation of a large cohort of over 1000 men demonstrated identical psm for bns and control group , which was 13.8% . in a new prospective ,
randomised , controlled and blinded study from the heidelberg group , only 2% of bns group had a sole psm at the bn compared with 12.5% psm rate in the control group .
published results of their prospective study , where they ceased recruitment after 70 patients as the psm rate was 10% , all being at the bn irrespective of the group . in lrp ,
katz et al . published results of the series , where overall psm was 26% and psm at bn as 9.75% . during the study ,
several studies stressed that appropriate patient selection is crucial in order not to compromise the surgical outcome .
oncological outcomes of bns high gleason score on the prostatic biopsies or suspicion of extra - prostatic extension increases the risk of psm at the bn .
aydin et al . described the significance of a sole psm at the bn . in his retrospective study of 164 men with psm after orp , 23% had sole psm at the bn .
those patients had 69.8% 5-year actuarial risk of biochemical progression compared with 33% who had negative bn margin .
the data highlights that the presence of a psm at the bn has a significant impact on long - term outcomes .
both marcovich et al . and aydin et al . have found that a psm at the bn results in higher rates of biochemical recurrence when compared with single or multiple psm at other sites .
however , in 2010 , pierorazio et al . published the results of large review on over 17,000 patients .
patients with an isolated psm at the bn had prostate specific antigen ( psa ) free survival rate of 37% and cancer free survival of 92% , which was comparable to prognosis of patients with a seminal vesicle invasion and an extracapsular extension respectively .
they concluded that american joint committee on cancer should reconsider bn involvement staging as t4 . assessing long - term oncological outcomes
, we were able to identify only four studies where biochemical recurrence - free survival ( bcrfs ) in bns cohorts was compared with non - bns cohort .
assessed psa , surgical margin status and pathological stage and grade and demonstrated no difference in bcrfs between bns and control groups with a follow - up period of up to 72 months ( hazard ratio 1.20 , 95% confidence interval 0.62 - 2.31 , p = 0.596 ) .
reported that during 7-year of follow - up , bns did not compromise disease free survival ( dfs ) .
univariable and multivariable analyses of psm at bns was not a statistically important factor for dfs .
licht et al . also assessed dfs between bns and non - bns groups and showed no statistical difference .
reported that at 5.2-year follow - up , 90% of bns group had a psa of less than 0.2
mcg / l and 80% of the non - bns group had a psa of less than 0.2
post - operative return to uc is similar in the reported orp , lrp and ralp series . where the bn was preserved uc varies between 36% and 100% at 1 month and 84% to 100% at 12 months follow - up .
table 2 summarises the relevant studies . as with the assessment of oncological outcomes , only one study provides 1b level of evidence .
the method of assessment of uc post - rp has always been controversial and there is no consensus definition . in a prospective study lowe defined uc as usage of zero pads per day . in his series ,
uc at 1 month was 23% in the bns group and 11% in the non - bns group were continent , which was statistically significant .
long - term uc was similar , 89% and 86% bns and non - bns cohorts respectively .
studied continence in patients undergoing orp and bladder bnr ( anterior bladder tube reconstruction [ abtr ] vs. tennis racket repair [ trr ] ) . pre - and post - operative urodynamics studies were performed to evaluated continence parameters .
differences in maximal urethral closing pressures were the only statistically significant findings between both groups post - operatively .
following analysis , preservation of functional urethral length was significantly longer in patients undergoing abtr .
furthermore , poon et al . compared outcomes of bns with abtr and trr . at intervals of 1 week ,
4 weeks , 3 months , 6 months and 12 months there was no statistical difference in uc among those groups . no significant difference in uc at 6 months was noted by srougi et al .
, however , due to the high prevalence of psm at the bn recruitment to the study was halted pre - maturely .
a significant improvement in uc post - bns was reported by gaker and steel , and deliveliotis et al . in both prospective studies , early return of uc in bns groups
the study of 600 patients undergoing lrp reported a return to uc at 12 months at 84% .
bns was associated with a statistically insignificant faster recovery of uc at 3 months and statistically significant difference in uc at 12 months between bns and non - bns groups , 94.9% and 80.1% , respectively using one pad or less as a definition of continence .
more recently , studies aiming at evaluation of bns technique in ralp have been published .
reported significantly better early uc in bns group versus non - bns group at 65.6% and 26.5% respectively . at 2-year follow - up
, there was no statistical difference between bns and non - bns groups and was 100% and 96.1% , respectively . in 2012
in a large retrospective cohort of 1067 men showed a significant improvement in early uc between bns and control groups particularly at 5 and 12 months follow - up . in another study , you et al .
compared functional outcomes of ralp with bns and bns plus posterior urethral reconstruction ( pur ) ; however , their study was performed retrospectively on a relatively small sample .
nevertheless , it demonstrated a significant improvement in return to uc between a control and pur groups and control and bns - pur groups .
the authors concluded that pur and bns are related with improved uc post - ralp .
the only prospective , randomised , controlled , blinded study comes from the heidelberg group .
84.2% of patients with bns were continent compared with 55.3% in non - bns procedure .
similarly at 12 months , the difference in uc was statistically significant and rates were 94.5% and 81.4% for bns and non - bns groups .
moreover , in the multiple logistic regression analysis bns was an independent positive predictor of uc .
functional outcomes post - bns gomez et al . were reported that neo vesico - urethral anastomosis stricture rate were lower in bns group compared with the non - bns group .
subsequent literature consistently supported these findings and currently there is an agreement that stricture rate post - bns is relatively lower than in patients not undergoing bns .
poon et al . reported bn stricture at 5% for bns and 11 - 18% for bnr techniques .
gaker and steel in 2004 reported that 2.9% of bns patient had an anastomotic stricture .
other studies present similar findings . in 2004 , besarani et al . demonstrated that strictures occur mostly within 3 months post - surgery ( 75% ) and are less frequent after 12 months from surgery ( 5% ) .
more recently , the heidelberg group did not observe the occurrence of any bn strictures post - rp in either bns and control groups .
available evidence suggests that bns technique is likely to be superior to non - bns for preventing anastomotic strictures .
however , most of evidence comes from non - randomised trials hence level of evidence is relatively low .
post - operative return to uc is similar in the reported orp , lrp and ralp series . where the bn was preserved uc varies between 36% and 100% at 1 month and 84% to 100% at 12 months follow - up .
table 2 summarises the relevant studies . as with the assessment of oncological outcomes , only one study provides 1b level of evidence .
the method of assessment of uc post - rp has always been controversial and there is no consensus definition . in a prospective study lowe defined uc as usage of zero pads per day . in his series ,
uc at 1 month was 23% in the bns group and 11% in the non - bns group were continent , which was statistically significant .
long - term uc was similar , 89% and 86% bns and non - bns cohorts respectively .
studied continence in patients undergoing orp and bladder bnr ( anterior bladder tube reconstruction [ abtr ] vs. tennis racket repair [ trr ] ) . pre - and post - operative urodynamics studies were performed to evaluated continence parameters .
differences in maximal urethral closing pressures were the only statistically significant findings between both groups post - operatively .
following analysis , preservation of functional urethral length was significantly longer in patients undergoing abtr .
furthermore , poon et al . compared outcomes of bns with abtr and trr . at intervals of 1 week ,
4 weeks , 3 months , 6 months and 12 months there was no statistical difference in uc among those groups . no significant difference in uc at 6 months was noted by srougi et al .
, however , due to the high prevalence of psm at the bn recruitment to the study was halted pre - maturely .
a significant improvement in uc post - bns was reported by gaker and steel , and deliveliotis et al . in both prospective studies , early return of uc in bns groups
the study of 600 patients undergoing lrp reported a return to uc at 12 months at 84% .
bns was associated with a statistically insignificant faster recovery of uc at 3 months and statistically significant difference in uc at 12 months between bns and non - bns groups , 94.9% and 80.1% , respectively using one pad or less as a definition of continence .
more recently , studies aiming at evaluation of bns technique in ralp have been published .
reported significantly better early uc in bns group versus non - bns group at 65.6% and 26.5% respectively . at 2-year follow - up
, there was no statistical difference between bns and non - bns groups and was 100% and 96.1% , respectively . in 2012
in a large retrospective cohort of 1067 men showed a significant improvement in early uc between bns and control groups particularly at 5 and 12 months follow - up . in another study , you et al .
compared functional outcomes of ralp with bns and bns plus posterior urethral reconstruction ( pur ) ; however , their study was performed retrospectively on a relatively small sample .
nevertheless , it demonstrated a significant improvement in return to uc between a control and pur groups and control and bns - pur groups .
the authors concluded that pur and bns are related with improved uc post - ralp .
the only prospective , randomised , controlled , blinded study comes from the heidelberg group .
84.2% of patients with bns were continent compared with 55.3% in non - bns procedure .
similarly at 12 months , the difference in uc was statistically significant and rates were 94.5% and 81.4% for bns and non - bns groups .
moreover , in the multiple logistic regression analysis bns was an independent positive predictor of uc .
gomez et al . were reported that neo vesico - urethral anastomosis stricture rate were lower in bns group compared with the non - bns group .
subsequent literature consistently supported these findings and currently there is an agreement that stricture rate post - bns is relatively lower than in patients not undergoing bns .
poon et al . reported bn stricture at 5% for bns and 11 - 18% for bnr techniques .
gaker and steel in 2004 reported that 2.9% of bns patient had an anastomotic stricture .
other studies present similar findings . in 2004 , besarani et al . demonstrated that strictures occur mostly within 3 months post - surgery ( 75% ) and are less frequent after 12 months from surgery ( 5% ) .
more recently , the heidelberg group did not observe the occurrence of any bn strictures post - rp in either bns and control groups .
available evidence suggests that bns technique is likely to be superior to non - bns for preventing anastomotic strictures .
however , most of evidence comes from non - randomised trials hence level of evidence is relatively low .
there is a growing body of literature on the role of bns in rp , although outcome data is still mainly based on non - randomised , prospective and retrospective studies with variable sample size ( level 2 - 4 evidence ) .
only one randomised , controlled , blinded study has been performed to date ( level 1b ) . in the studies reviewed , psm rates varied between 6% and 32% .
katz et al . in his prospective series reported that after abandoning the bns technique the psm rate dropped by 9.75% , however , total psm rate was still 26% .
those findings were not confirmed by other studies , which documented that psm did not negatively correlate with bns technique .
moreover , newer , larger review postulates that sole psm at bn is very rare ( 1.2% ) and if present confers 12-year cancer free survival of 92% .
while there is no agreement , it appears that the only absolute contraindication is high risk disease which increases the risk of psm involving bn .
a relative contraindication is a previous pelvic or transurethral prostate surgery as this may increase technical intraoperative difficulties .
some authors postulate additional investigations pre - operatively such as additional bladder base biopsies , pre - operative magnetic resonance imaging , and biopsies of the spared bn .
the only randomised , prospective study on the subject concluded that bns does not negatively impact oncological outcomes .
the sole psm rate at bn was only 2% compared with total psm rate being 13.6% .
this study also reported objective and subjective assessment of uc and demonstrated that bns enables early return of uc and long - term uc . in the remaining studies included in our review ,
lowe et al . defined uc as zero pads per day while srougi et al .
other series used an open interview as a method of assessment of uc without any validated questionnaires .
more recently international continence society ( ics ) male and ics male short - form were utilised by others .
available data uniformly shows that uc rates post - rp with bns are at least as good as post non - bns and it is very likely that bns expedites early return of uc and improves long - term uc .
with changes in surgical technique , bns has been increasingly incorporated into the rp . evidence summarised in this review
demonstrates that bns technique leads to early return of uc and long - term uc without compromising oncological outcomes .
bns is superior to non - bns techniques and authors of this review postulate application of the method in feasible cases .
 the role of a bladder neck sparing ( bns ) technique in radical prostatectomy ( rp ) remains controversial . 
 the potential advantages of improved functional recovery must be weighed against oncological outcomes . 
 we performed a literature review to evaluate the current knowledge regarding oncological and functional outcomes of bns and bladder neck reconstruction ( bnr ) in rp . 
 a systematic literature review using on - line medical databases was performed . 
 a total of 33 papers were identified evaluating the use of bns in open , laparoscopic and robotic - assisted rp . 
 the majority were retrospective case series , with only one prospective , randomised , blinded study identified . 
 the majority of papers reported no significant difference in oncological outcomes using a bns or bnr technique , regardless of the surgical technique employed . quoted positive surgical margin rates ranged from 6% to 32% . 
 early urinary continence ( uc ) rates were ranged from 36% to 100% at 1 month , with long - term uc rate reported at 84 - 100% at 12 months if the bladder neck ( bn ) was spared . 
 bns has been shown to improve early return of uc and long - term uc without compromising oncological outcomes . 
 anastomotic stricture rate is also lower when using a bns technique . 
INTRODUCTION
Oncological outcomes
Functional outcomes
Urinary continence
Anastomotic strictures
DISCUSSION
CONCLUSION