The Impact of Lateral Bladder Neck Preservation on Urinary Continence Recovery After Robot-Assisted Radical Prostatectomy

Abstract

Objective:

Urinary incontinence is one of the most bothersome adversities after robot-assisted radical prostatectomy (RARP). The aim of this study was to investigate the urinary continence recovery and the effect of various surgical techniques.

Materials and Methods:

We previously reported that posterior rhabdosphincter reconstruction and nerve-sparing were independent predictors of urinary continence recovery 1 month after catheter removal in 199 patients who underwent RARP. Retrospectively, we further reviewed those 199 patients for urinary continence recovery at 3 months or later after RARP. The relationships of urinary continence with perioperative findings, including surgical procedures, were evaluated at 3 to 12 months after RARP. The Fisher exact test and Mann–Whitney rank sum test were used for evaluating variables between the groups. Multivariate logistic regression analysis was performed to investigate the association between urinary continence and perioperative factors.

Results:

On univariate analyses, surgeon experience, lateral bladder neck preservation (BNP), anterior reconstruction, and posterior reconstruction were significantly associated with urinary continence recovery 3 months after RARP, but only lateral BNP was independently associated with urinary continence recovery in a multivariate analysis. Similarly, on univariate analyses, surgeon experience, lateral BNP, and posterior reconstruction were significantly associated with continence recovery at 6 months or later after surgery. However, multivariate analyses showed that only lateral BNP was significantly associated with urinary continence recovery 6 months or later after surgery.

Conclusion:

Although the lateral BNP technique did not affect immediate urinary continence recovery, this procedure was significantly associated with continence recovery 3 months or later after RARP.

Introduction

Oncologic control, continence, and potency were used for evaluating the accomplishment after radical prostatectomy (RP). After RP, postoperative urinary incontinence might be a major concern for patients because it may impair quality of life. Although urinary continence recovery depends on various patient factors, the surgical technique is considered the most critical factor for urinary continence because surgical technique is the only factor for continence recovery that can be improved by ingenuity and effort of the surgeon. Subsequently, the surgical technique used during RP has been continuously refined to improve urinary continence recovery.

In a previous systematic review of the literature, the 12-month urinary continence recovery after robot-assisted RP (RARP) in referral centers ranged from 84% to 97%.¹ Indeed, RARP has been shown to have higher postoperative urinary continence recovery rates than open radical prostatectomy (ORP) or laparoscopic radical prostatectomy (LRP). However, urinary incontinence has remained one of the most bothersome postoperative complications even after RARP.

Although some reports have supported the effectiveness of the surgical modifications, such as posterior reconstruction and nerve-sparing or bladder neck preservation (BNP) from the ORP era,^2

–9 most modifications were speculated to have a limited role, particularly after longer follow-up periods. Robot-assisted surgery combining optical magnification, three-dimensional vision, and flexible instruments allows surgeons to perform meticulous, precise, and accurate movements that are fundamental in preserving the key anatomic structures for urinary continence.¹⁰ Therefore, we hypothesize that surgical modifications during RARP potentially provide further benefit compared with modifications during ORP or LRP. We previously reported that the Rocco double-layered posterior reconstruction and nerve-sparing procedure were significant independent predictive factors for urinary continence recovery 1 month after RARP.¹¹ However, there is a lack of evidence of the impact of surgical modifications during RARP on long-term continence recovery. Therefore, this study investigated the association of perioperative factors, including surgical techniques, with the long-term urinary continence recovery after RARP.

Patients and Methods

We previously reported about urinary continence recovery 1 month after RARP in 199 patients who underwent RARP performed by a single surgeon (K.Y.) between August 2006 and April 2011. In that study, we reported that the Rocco posterior rhabdosphincter reconstruction and attempted nerve-sparing were independent predictive factors of urinary continence recovery 1 month after surgery on multivariate logistic regression analysis. When we applied nerve-sparing as well as the Rocco posterior rhabdosphincter reconstruction, the urinary continence recovery rate of continence at 1 month after catheter removal was 85.3%.¹¹ In this study, we performed further retrospective analysis of the perioperative factors associated with 3-, 6-, 9-, and 12-month continence recovery in those 199 patients. The details of the patient's characteristics were shown in our previous report.¹¹ This study was approved by our facility's ethics committee. Postoperative urinary continence was defined as either no use or use of only one safety pad per day. We evaluated postoperative urinary continence by interviews at each patient visit. All patients were followed up at least every 3 months in the first year after surgery. We used the Fisher exact test and Mann–Whitney rank sum test for evaluating categorical and quantitative variables, respectively. Multivariate logistic regression analysis was performed to investigate the association between the status of urinary continence and perioperative factors. The significance level was p < 0.05. All statistical analyses were performed by using Stata (ver. 14.0; StataCorp, College Station, TX).

Surgical procedure

All procedures were performed based on the Patel technique, with minor modifications.¹² The RARP modifications in our institution were described in a previous report.¹¹ Three surgical approaches for bladder neck approach have been reported up to the present time: anterior, anterolateral, and lateral approaches.¹³ Of those approaches, bladder neck dissection was attempted by using the anterior or lateral bladder neck approach with BNP in this study. The lateral BNP approach was performed by using ultradissection, an accurate method previously reported by Jeong and colleagues¹⁴ The lateral BNP technique requires precise identification of the detrusor muscle fibers at the junction of the lateral bladder neck and prostate base. We first extended the space on the side of the bladder neck until the seminal vesicles were detected at the lateral approach; then, the border between the prostate and bladder was transected with preservation of the circular muscle fibers of the bladder neck until the proximal urethral mucosa was evident; and the mucosa was finally incised. Basically, indications for lateral BNP were based on the consideration of the attending physician. Initially, we thought that an estimated prostate volume of ≥40 g, prostate median lobe enlargement, and/or an asymmetrical prostate might cause difficulty during dissection of the prostate bladder junction; thus, they were adapted for lateral BNP. After we introduced lateral BNP to some patients, we gradually expanded the indication for this technique to include all patients, except for those whose prostate cancer was suspected as having invaded the bladder neck. The number of patients who underwent the modified surgical technique is shown in Table 1 as previously reported. Each surgical technique was described in our previous report.¹¹

Table 1.

Patients’ Demographics

Age, years, mean (SD)	64.5 (0.48)
Serum PSA, ng/mL, mean (SD)	10.19 (0.66)
Body mass index, kg/m², mean (SD)	23.7 (0.19)
Prostate weight, mL, mean (SD)	39.5 (19.7)
Clinical T stage, n (%)
T_1c	169 (85.0)
T_2a	15 (7.5)
T_2b	8 (4.0)
T_2c	2 (1.0)
T₃	5 (2.5)
Biopsy Gleason score, n (%)
≤6	62 (31.2)
7	97 (48.7)
≥8	40 (20.1)
Nerve sparing, n (%)
Non-nerve spearing	101 (50.8)
Unilateral spearing	84 (42.2)
Bilateral spearing	14 (7.0)
Bladder neck dissection, n (%)
Anterior approach	77 (38.7)
Lateral approach with BNP	122 (61.3)
Posterior reconstruction, n (%)	160 (80.4)
Anterior reconstruction, n (%)	159 (79.9)
Bladder neck reconstruction, n (%)	40 (20.1)
Pathological T stage, n (%)
T₀	1 (0.5)
T_2a	28 (14.1)
T_2b	73 (36.7)
T_2c	28 (14.1)
T₂₊	18 (9.0)
T_3a	39 (19.6)
T_3b	11 (5.5)
T₄	1 (0.5)
Pathological Gleason score, n (%)
≤6	20 (10.0)
7	132 (66.3)
≥8	47 (23.6)
Continence recovery rate, n (%)
Hospital day	84 (42.2)
1 Month after surgery	128 (64.3)
3 Months after surgery	160 (80.4)
6 Months after surgery	174 (87.4)
9 Months after surgery	184 (92.5)
12 Months after surgery	188 (94.5)

BNP = bladder neck preservation; PSA = prostate-specific antigen; SD = standard deviation.

Results

All patients had a good performance status at the time of RARP, and all RARPs were successfully performed during the study period. The characteristics and urinary continence recovery rate at 3-, 6-, 9-, and 12-month continence recovery after RARP in 199 patients are shown in Table 1. In univariate analyses, surgeon experience, lateral BNP, anterior reconstruction, and posterior reconstruction were significantly associated with urinary continence recovery 3 months after RARP (p < 0.05). However, in multivariate analysis, only lateral BNP was independently associated with urinary continence recovery (Table 2, p < 0.01, 95% confidence interval [CI] 1.44–9.13, odds ratio [OR] 3.62). Six months after RARP, surgeon experience, lateral BNP, and posterior reconstruction were significantly associated with urinary continence recovery in univariate analysis (p < 0.05). In contrast, in multivariate analysis, only lateral BNP was independently associated with urinary continence recovery after RARP (p < 0.01, 95% CI 1.69–16.7, OR 5.30). Similarly, surgeon experience, lateral BNP, and posterior reconstruction were significantly associated with urinary continence recovery in univariate analysis 9 months or later after RARP; however, only lateral BNP was independently associated with urinary continence recovery in multivariate analyses (Table 2; 9 months: p = 0.04, 95% CI 1.12–22.6, OR 5.03; 12 months: p = 0.02, 95% CI 1.42–58.6, OR 9.12). The posterior reconstruction and nerve-sparing procedure, which were reported as significant predictors for early continence recovery in our previous study, were not independently associated with late urinary continence recovery. Instead, lateral BNP was significantly associated with urinary continence recovery 3 months or later after surgery.

Table 2.

Relationship Continence and Perioperative Variables at Each Period After Robot-Assisted Radical Prostatectomy

	3 Months				6 Months
	Univariate	Multivariate			Univariate	Multivariate
	p	p	95% CI	OR	p	p	95% CI	OR
Perioperative variables
Age	0.49	0.24	0.91–1.02	0.96	0.92	0.77	0.93–1.06	0.99
PSA	0.11	0.14	0.98–1.16	1.07	0.25	0.33	0.95–1.16	1.05
BMI	0.34	0.28	0.93–1.29	1.10	0.12	0.07	0.99–1.45	1.20
Surgeon experience	<0.01	0.76	0.99–1.01	0.99	<0.01	0.17	1.00–1.02	1.01
Surgical procedure
Nerve-sparing procedure	0.94	0.29	0.67–3.73	1.58	0.83	0.54	0.51–3.63	1.36
Lateral BNP	<0.01	<0.01	1.44–9.13	3.62	<0.01	<0.01	1.69–16.7	5.30
Bladder neck reconstruction	0.18	0.58	0.50–3.47	1.32	0.12	0.88	0.31–2.72	0.92
Anterior reconstruction	<0.01	0.25	0.61–6.74	2.03	0.06	0.89	0.23–3.64	0.91
Posterior reconstruction	<0.01	0.21	0.58–12.2	2.67	<0.01	0.82	0.14–4.81	0.81

	9 Months				12 Months
Perioperative variables
Age	0.74	0.6	0.94–1.12	1.02	0.84	0.83	0.90–1.09	0.99
PSA	0.53	0.62	0.91–1.16	1.03	0.88	0.6	0.91–1.06	0.98
BMI	0.36	0.28	0.90–1.43	1.13	0.82	0.89	0.76–1.26	0.98
Surgeon experience	0.01	0.37	0.99–1.03	1.01	0.05	0.22	0.99–1.03	1.01
Surgical procedure
Nerve-sparing procedure	0.84	0.37	0.52–5.94	1.75	0.54	0.26	0.55–8.85	2.21
Lateral BNP	<0.01	0.04	1.12–22.6	5.03	<0.01	0.02	1.42–58.6	9.12
Bladder neck reconstruction	0.09	0.59	0.20–2.51	0.71	0.24	0.76	0.18–3.45	0.79
Anterior reconstruction	0.19	0.21	0.06–1.84	0.34	0.24	0.74	0.12–4.68	0.73
Posterior reconstruction	<0.01	0.48	0.24–21.6	2.27	0.04	0.66	0.05–6.56	0.58

BMI = body mass index; CI = confidence interval; OR = odds ratio.

Discussion

The cause of urinary incontinence after RP is complex and influenced by many factors. Both patient characteristics and the surgeon's skill can affect continence status after RP. Techniques such as nerve-sparing, BNP, posterior reconstruction of the rhabdosphincter, and anterior reconstruction have been shown to improve urinary incontinence after ORP or LRP.^2

–9 Some modifications were shown to be beneficial for continence recovery after introducing RARP.^{15

–24} However, most modifications were not standardized between centers and surgeons because those techniques were not easy to be duplicated by different surgeons. Therefore, it remains unclear as to which modification might be significantly associated with urinary continence recovery. To avoid the bias of the differences between surgeons and institutions in this study, we evaluated the surgical modifications to RP by a single surgeon in strict accordance with the techniques previously reported.

The BNP technique is one variation of bladder neck dissection that was first reported by Klein during ORP.² The BNP technique during ORP or LRP has been reported to be associated with an earlier urinary continence recovery^2
–4; however, this technique was shown to have a limited role in urinary continence recovery rates at 12 months after ORP or LRP.^25,26 Although bladder neck dissection is considered one of the difficult steps of RARP, robotic surgery enables us to perform precise bladder neck dissection by using the stable and magnified operative field offered by this technique. Careful dissection of the prostate and bladder junction using robotic surgery could maintain most of the circular muscle fibers of the bladder neck and accelerate urinary continence recovery by preserving the structural features of the urethral sphincter complex.^9,13 Therefore, the association of BNP during RARP with urinary continence recovery needs to be investigated. Mattei and colleagues²¹ reported that 80% of patients who underwent RARP with the BNP technique achieved continence recovery 1 week after catheter removal and 92.4% of patients achieved complete continence recovery after 4 weeks. Jeong and colleagues¹⁴ also reported that 91% continence recovery was observed in the patient group who underwent the BNP technique during RARP. Although these studies did not compare BNP with other procedures, the results suggested that the BNP technique potentially had an impact on urinary continence recovery after RARP.

After RARP was introduced, Friedlander and colleagues²² reported that urinary continence recovery of patients treated by the BNP procedure during RARP was faster than that of patients treated by a non-BNP procedure. Their study has supported that the benefit of BNP continues 12 months or later after RARP. Nyarangi-Dix and colleagues⁹ also reported a randomized controlled trial regarding BNP in patients treated with ORP or RARP. Although that study included both RARP and ORP, they noted significantly less urine leakage and higher continence recovery rates after BNP at any follow-up points. However, some reports showed that this procedure had a limited role in long-term return of continence. Freire and colleague¹⁵ reported that continence rates at 12 months after RARP in their study were not significantly different between the BNP and standard techniques, although continence recovery rates in patients with BNP at 4 months after RARP were significantly higher than those of the standard technique. Subsequently, they suggested that BNP was associated with quicker recovery of urinary function, similar to ORP or LRP. However, this study interestingly showed that BNP was significantly associated with continence recovery 1 year after RARP.

In this study, one of the concerns about BNP might be surgical margin status of the prostatectomy specimen and final oncologic outcome. Of the 122 patients who were treated with lateral BNP, 26 patients (21.3%) had positive surgical margin in the prostatectomy specimen. On the other hand, 19 patients (24.7%) had positive surgical margin out of 77 patients who were treated with the anterior approach. Further, only three patients suffered from positive surgical margin on the proximal side in patients treated by lateral BNP, but two patients suffered from positive surgical margin on the proximal side in patients treated by the anterior approach. In addition, we did not find any differences between the two groups in terms of positive surgical margin. This fact suggested that lateral BNP might not increase positive margin of the proximal side. In addition, 46 patients (23.1%) experienced biochemical recurrence during the entire follow-up period, and the 5-year non-biochemical, recurrence-free survival rate in this cohort was 76.7%. As expected, there was no statistical significance in terms of biochemical recurrence after RARP between the two groups. Therefore, we suggested that the carful lateral BNP approach for bladder prostate junction does not influence positive surgical margin and oncological outcomes.

Few reports have evaluated urinary continence with relatively long-term follow-up periods; they were limited to standardized BNP procedure performed by a single surgeon. Although some BNP techniques were reported by various surgeons from the ORP era, the BNP technique performed in this study was previously described in detail by Jeong and colleagues¹⁴ Since this lateral BNP technique does not require advanced skills and longer time during surgery, this technique is acceptable for us to introduce during RARP. In addition, we investigated a single surgeon's series to eliminate surgeon bias and applied modifications reported from other institutions. Therefore, our study could suggest that the lateral BNP technique was a reproducible method and was effective in improving urinary continence after RARP.

Recently, some studies showed that the nerve-sparing procedure and posterior rhabdosphincter reconstruction were correlated with early recovery of continence after RARP. However, the nerve-sparing procedure and posterior reconstruction were speculated to have an impact on only early continence recovery.^27

–30 In fact, posterior rhabdosphincter reconstruction and the nerve-sparing procedure were significantly associated with early urinary continence recovery in our previous report,¹¹ although this study did not show that these techniques had an impact on urinary continence recovery at 3 months or later after RARP. In contrast, lateral BNP was not associated with immediate urinary continence recovery; however, this procedure was significantly associated with late urinary continence recovery. Therefore, we suggest that lateral BNP with the nerve-sparing procedure and posterior reconstruction is the most effective procedure with respect to both early and late continence recovery after RARP.

Although we believe that this study provides important insights about urinary continence recovery after RARP, this study has some limitations. First, this was a retrospective study that involved analysis of data collected from patients who underwent RARP by a single surgeon who is supposed to be the most experienced in the performance of RARP in our country. Second, the patients in this study were not randomly assigned. Therefore, this retrospective study has a potential selection bias. Nonetheless, we still believe that our results are useful to decrease urinary incontinence after RARP. In light of the current situation, further prospective studies are warranted to confirm our results regarding RARP.

Conclusion

Although the lateral BNP technique did not affect immediate continence recovery, this procedure was significantly associated with continence recovery 3 months or later after RARP.

Footnotes

Author Disclosure Statement

No competing financial interests exist.

Abbreviations Used

References

Ficarra

, Novara

, Rosen

, et al. A systematic review and meta-analysis of studies reporting urinary continence recovery after robot-assisted radical prostatectomy. Eur Urol, 2012; 62:405–417.

Klein

. Early continence after radical prostatectomy. J Urol, 1992; 148:92–95.

Licht

, Klein

, Tuason

, et al. Impact of bladder neck preservation during radical prostatectomy on continence and cancer control. Urology, 1994; 44:883–887.

Braslis

, Petsch

, Lim

, et al. Bladder neck preservation following radical prostatectomy: Continence and margins. Eur Urol, 1995; 28:202–208.

Burnett

, Mostwin

. In situ anatomical study of the male urethral sphincteric complex: Relevance to continence preservation following major pelvic surgery. J Urol, 1998; 160:1301–1306.

Rocco

, Carmignani

, Acquati

, et al. Restoration of posterior aspect of rhabdosphincter shortens continence time after radical retropubic prostatectomy. J Urol, 2006; 175:2201–2206.

Rocco

, Gregori

, Stener

, et al. Posterior reconstruction of the rhabdosphincter allows a rapid recovery of continence after transperitoneal videolaparoscopic radical prostatectomy. Eur Urol, 2007; 51:996–1003.

Wei

, Dunn

, Marcovich

, et al. Prospective assessment of patient reported urinary continence after radical prostatectomy. J Urol, 2000; 164:744–748.

Nyarangi-Dix

, Radtke

, Hadaschik

, et al. Impact of complete bladder neck preservation on urinary continence, quality of life and surgical margins after radical prostatectomy: A randomized, controlled, single blind trial. J Urol, 2013; 189:891–898.

10.

Lee

, Sehgal

, Graves

, et al. Functional and oncologic outcomes of graded bladder neck preservation during robot-assisted radical prostatectomy. J Endourol, 2014; 28:48–55.

11.

Gondo

, Yoshioka

, Hashimoto

, et al. The powerful impact of double-layered posterior rhabdosphincter reconstruction on early recovery of urinary continence after robot-assisted radical prostatectomy. J Endourol, 2012; 26:1159–1164.

12.

Patel

, Tully

, Holmes

, et al. Robotic radical prostatectomy in the community setting—The learning curve and beyond: Initial 200 cases. J Urol, 2005; 174:269–272.

13.

Kojima

, Takahashi

, Haga

, et al. Urinary incontinence after robot-assisted radical prostatectomy: Pathophysiology and intraoperative techniques to improve surgical outcome. Int J Urol, 2013; 20:1052–1063.

14.

Jeong

, Araki

, Park

, et al. Robot-assisted laparoscopic radical prostatectomy in the Asian population: Modified port configuration and ultradissection. Int J Urol, 2010; 17:297–300.

15.

Freire

, Weinberg

, Lei

, et al. Anatomic bladder neck preservation during robotic-assisted laparoscopic radical prostatectomy: Description of technique and outcomes. Eur Urol, 2009; 56:972–980.

16.

You

, Kim

, Sung

. Effect of bladder neck preservation and posterior urethral reconstruction during robotassisted laparoscopic radical prostatectomy for urinary continence. Korean J Urol, 2012; 53:29–33.

17.

Patel

, Coelho

, Palmer

, et al. Periurethral suspension stitch during robot-assisted laparoscopic radical prostatectomy: Description of the technique and continence outcomes. Eur Urol, 2009; 56:472–478.

18.

Takenaka

, Tewari

, Leung

, et al. Preservation of the puboprostatic collar and puboperineoplasty for early recovery of urinary continence after robotic prostatectomy: Anatomic basis and preliminary outcomes. Eur Urol, 2007; 51:433–440.

19.

Gautam

, Rocco

, Patel

, et al. Posterior rhabdosphincter reconstruction during robot-assisted radical prostatectomy: Critical analysis of techniques and outcomes. Urology, 2010; 76:734–741.

20.

Tewari

, Jhaveri

, Rao

, et al. Total reconstruction of the vesico-urethral junction. BJU Int, 2008; 101:871–877.

21.

Mattei

, Naspro

, Annino

, et al. Tension and energy-free robotic-assisted laparoscopic radical prostatectomy with interfascial dissection of the neurovascular bundles. Eur Urol, 2007; 52:687–694.

22.

Friedlander

, Alemozaffar

, Hevelone

, et al. Stepwise description and outcomes of bladder neck sparing during robot-assisted laparoscopic radical prostatectomy. J Urol, 2012; 188:1754–1760.

23.

, Tang

, Yang

, et al. Bladder neck preservation improves time to continence after radical prostatectomy: A systematic review and meta-analysis. Oncotarget, 2016; 7:67463–67475.

24.

, Araki

, Wong

. Continence outcomes after bladder neck preservation during robot-assisted laparoscopic prostatectomy (RALP). Minim Invasive Ther Allied Technol, 2015; 24:364–371.

25.

Deliveliotis

, Protogerou

, Alargof

, et al. Radical prostatectomy: Bladder neck preservation and puboprostatic ligament sparing—Effects on continence and positive margins. Urology, 2002; 60:855–858.

26.

Shelfo

, Obek

, Soloway

. Update on bladder neck preservation during radical retropubic prostatectomy: Impact on pathologic outcome, anastomotic strictures, and continence. Urology, 1998; 51:73–78.

27.

Suardi

, Moschini

, Gallina

, et al. Nerve-sparing approach during radical prostatectomy is strongly associated with the rate of postoperative urinary continence recovery. BJU Int, 2013; 111:717–722.

28.

Srivastava

, Chopra

, Pham

, et al. Effect of a risk-stratified grade of nerve-sparing technique on early return of continence after robot-assisted laparoscopic radical prostatectomy. Eur Urol, 2013; 63:438–444.

29.

Rocco

, Carmignani

, Acquati

, et al. Early continence recovery after open radical prostatectomy with restoration of the posterior aspect of the rhabdosphincter. Eur Urol, 2007; 52:376–383.

30.

Coelho

, Chauhan

, Orvieto

, et al. Influence of modified posterior reconstruction of the rhabdosphincter on early recovery of continence and anastomotic leakage rates after robot-assisted radical prostatectomy. Eur Urol, 2011; 59:72–80.