The Powerful Impact of Double-Layered Posterior Rhabdosphincter Reconstruction on Early Recovery of Urinary Continence After Robot-Assisted Radical Prostatectomy

Abstract

Background and Purpose:

The usefulness of posterior rhabdosphincter reconstruction (PR) during robot-assisted radical prostatectomy (RARP) has still been controversial. We investigated the association of several factors, including the Rocco original double-layered PR, with early recovery of urinary continence after RARP.

Patients and Methods:

Between August 2006 and April 2011, a single surgeon at Tokyo Medical University Hospital performed 206 RARPs. Of these 206 patients, 199 eligible patients were enrolled in this study. We retrospectively analyzed the correlation of several perioperative factors, including surgical techniques, with early recovery of urinary continence 1 month after catheter removal. Continence was defined as no use or the use of only one safety pad.

Results:

Univariate analysis showed that surgeon experience, lateral approach of bladder neck preservation, bladder neck reconstruction, anterior reconstruction, and the Rocco double-layered PR were significantly associated with early recovery of urinary continence 1 month after catheter removal. Preoperative prostate-specific antigen level, body mass index, and attempted nerve-sparing (NS) procedures, however, were not significantly associated with early recovery of urinary continence. Multivariate logistic regression analysis showed that the Rocco PR and attempted NS were the only independent predictive factors of urinary continence recovery 1 month after catheter removal (odds ratio [OR], 15.01; 95% confidence interval [CI], 3.413–66.67; P=0.0003 and OR, 2.248; 95% CI, 1.048–4.975; P=0.0402, respectively). When we applied NS as well as the Rocco PR, the recovery rates of continence at 1 month after catheter removal was 85.3%.

Conclusions:

The Rocco double-layered PR and attempted NS and not surgeon experience were the significant independent predictive factors of early recovery of urinary continence after RARP. NS procedures positively influenced early recovery of urinary continence only when they were applied with the PR technique.

Introduction

P rostate cancer is one of the most common cancers in Europe.¹ In Japan, the incidence of prostate cancer has gradually increased, and it is expected to be the second-most frequent cancer within 10 years. Although various treatment options are available, radical prostatectomy remains the standard treatment for localized prostate cancer.² Despite the excellent oncologic results of this procedure, many patients choose alternative treatments because they fear the invasiveness of radical surgery, postoperative pain, and potential side effects, such as incontinence and erectile dysfunction.

Urinary incontinence is a major drawback that can reduce a patient's quality of life (QoL) after radical prostatectomy. Recently, the use of robot-assisted radical prostatectomy (RARP) with the da Vinci Surgical System (Intuitive Surgical, Sunnyvale, CA) has spread to several institutions, and excellent long-term continence outcomes after RARP have been consistently reported. The 1-year continence rate is >90% in most large single-center prospective studies.^3,4 The time to continence recovery, however, remains a matter of concern. Urologists have attempted to decrease incontinence rates and have developed several surgical techniques for early recovery of urinary continence after radical prostatectomy; these surgical techniques include bladder neck preservation (BNP),^5

–8 periurethral suspension techniques,⁹ puboprostatic ligament sparing,¹⁰ preservation of the puboprostatic collar and puboperineoplasty,¹¹ posterior reconstruction (PR) of the rhabdosphincter,^12,13 and anterior reconstruction (AR), and/or total pelvic reconstruction.¹⁴ Despite these technical modifications, the factors correlated with early recovery of urinary continence remain unclear because of the lack of standardized surgical application of these techniques between centers, varied surgical experience, discrepancies in the definition of status, and the methods of evaluating urinary continence.

In 2006, Rocco and associates¹⁵ adopted the posterior rhabdosphincter reconstruction technique and reported excellent postoperative continence rates of 72% at day 3 after catheter removal following open radical prostatectomy.¹⁵ Subsequently, they showed similar continence rates in their laparoscopic and RARP series by using the same technique.^12,13 Given these promising continence outcomes, several centers have evaluated the efficacy of PR in early recovery of urinary continence after radical prostatectomy. The results, however, are widely varied between centers with several studies reporting improved outcomes after adopting PR,^14,16,17 while others, including a small prospective randomized study, reporting equivalent results.^18,19 One possible explanation for these discrepant results is the layer of sutures in the PR procedure.

We introduced the da Vinci Surgical System to our institution in 2006, and more than 400 RARPs have since been performed using this system. In this study, we retrospectively reviewed the records of patients who underwent RARP by a single surgeon and analyzed the correlation of several possible factors, including the Rocco original double-layered PR technique, with early recovery of urinary continence to identify predictive factors.

Patients and Methods

Between August 2006 and April 2011, 352 patients with nonmetastatic prostate cancer underwent RARP performed by seven surgeons at our institution. Of 352 RARPs, 206 were performed by a single surgeon (KY), and we focused on these 206 patients in the present study to eliminate surgical skill bias caused by different surgeons. Case 1, in which operation time had been restricted to 2 hours by the ethics committee at our institution, was converted to an open procedure and excluded from this analysis. Six other patients were excluded from this study because postoperative continence status data were unavailable, resulting in 199 patients who were eligible for this analysis. For these 199 patients, we performed a retrospective analysis of the factors correlated with early recovery of urinary continence after RARP. This study was approved by the ethics committee at Tokyo Medical University. Postoperative continence was defined as no use or the use of only one safety pad. We evaluated postoperative urinary continence by clinic interviews at each visit.

Surgical techniques

All procedures were performed based largely on the Patel technique²⁰ with minor modifications. The BNP procedure was attempted for all patients using one of two different approaches: The anterior approach or the lateral approach. Briefly, for the anterior approach, we dissected the border between the bladder and prostate through the anterior wall of the bladder, whereas for the lateral approach, we first extended the space on the side of the bladder neck until detecting seminal vesicles; 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; finally, the mucosa was incised. The merit of the latter procedure is early identification of the shape of the bladder neck, allowing more precise bladder neck preservation compared with the former procedure, especially in cases with a large prostate with protruded middle lobe into the bladder.

The nerve sparing (NS) procedure was performed athermally, with an early retrograde release of the neurovascular bundles before ligation of the prostatic pedicles, as reported previously.²¹ The PR technique was carried out before vesicourethral anastomosis. We followed the Rocco original PR method as close as possible.¹⁵ Briefly, two of the threads (12 cm of 3-0 poliglecaprone, RB-1 needles) are tied by their tails and used as double-ended needles. Reconstruction consists of two layers. The first layer is the fibrous tissue just beneath the urethra with the Denonvilliers fascia located halfway between the bladder and the urethra. The Denonvilliers fascia is distinct from other layers such as the posterior detrusor apron or posterior longitudinal fascia, which lie close to the Denonvilliers fascia, as reported previously.^22,23 The first important point is to pay attention not to put a stitch through the urethral mucosa. The second layer is the bladder muscle and the fibrous tissue just below the urethra. Again, attention should be paid not to put a stitch through the urethral mucosa. On the bladder side, a stitch should be put at a point 1 cm away from the bladder neck. This is the second important point and two of these points are performed to make one layer formed by the layer formed by PR separated from the layer formed at the time of anastomosis. As Rocco and coworkers¹⁵ have mentioned, these are the key points of the Rocco stitch to get an early recovery of urinary continence.

We initiated this PR technique in case 28, but we were not able to completely emulate this procedure; precise Rocco PR was sometimes difficult to perform because of the poor condition of the medial dorsal raphe behind the urethra. The AR technique was initiated in case 12 and randomly used during RARP, in which ligated dorsal venous complex and anterior muscle layer of the bladder (2 cm away from the neck) were approximated to reduce tension of the anastomosis. To evaluate the quality of each surgical technique, we reviewed the DVD-R of each surgical procedure included in our statistical analyses. We excluded 13 patients who did not have a precisely performed PR procedure by DVD-R review from the PR group.

Statistical analysis

The factors analyzed were patient age, body mass index (BMI), preoperative prostate-specific antigen (PSA) levels, surgeon experience (the number of cases experienced by the surgeon), and several surgical procedures (BNP approach, bladder neck reconstruction, AR, Rocco PR, and attempted NS procedure).

We used the chi-square test or the Fisher exact test for evaluating categorical variables and used the Student t test or Mann-Whitney rank sum test for evaluating quantitative variables between the two groups (continence vs incontinence). Continuous variables were described as the mean value plus or minus standard deviation. Multivariate logistic regression analysis was performed to investigate the association between status of urinary continence and the factors described above. All statistical analyses were performed using StatView (ver. 5.0; SAS, Cary, NC). P values of <0.05 were considered statistically significant.

Results

The characteristics of the 199 patients in this study were shown in Table 1. Most (97.5%) patients had clinically organ-confined prostate cancers (≤cT_2c). All patients had a good performance status at the time of RARP, and RARP was successfully performed in all patients. For 98 (49.2%) patients, the NS procedure was accomplished, including unilaterally in 84 (42.2%) patients and bilaterally in 14 (7.0%) patients. BNP was performed via the anterior approach in 77 (38.7%) patients and the lateral approach in 122 (61.3%) patients. Bladder neck reconstruction by tennis racket sutures was performed in 40 (20.1%) patients, and AR was performed in 159 (79.9%) patients. The Rocco PR technique was precisely performed in 160 (80.4%) patients by DVD-R reviews.

Table 1.

Characteristics of the 199 Patients Who Underwent Robot-Assisted Radical Prostatectomy by a Single Surgeon

Characteristics	No. (%) of patients
Age
Mean (median)	64.5±0.48 (65)
Range	39–77
Serum prostatic-specific antigen level (ng/mL)
Mean	10.19±0.66
Range	3.3–69.8
Body mass index
Mean	23.7±0.19
Range	17.2–37.9
Clinical T stage
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
≤6	62 (31.2)
7	97 (48.7)
≥8	40 (20.1)

Overall, 128 (64.3%) patients achieved continence 1 month after catheter removal. The results of univariate and multivariate analysis were shown in Table 2. Univariate analysis revealed that the surgeon experience, lateral approach of BNP, bladder neck reconstruction, AR, and Rocco PR were significantly associated with early recovery of urinary continence 1 month after catheter removal. Age, preoperative PSA level, BMI, and attempted NS procedure, however, were not significantly associated with early recovery of urinary continence. Multivariate logistic regression analysis revealed that attempted NS and Rocco PR were the only independent factors that predicted recovery of urinary continence 1 month after catheter removal (odds ratio [OR], 2.248; 95% confidence interval [CI], 1.048–4.975; P=0.0402 and OR, 15.01; 95% CI, 3.413–66.67; P=0.0003, respectively).

Table 2.

Univariate and Multivariate Logistic Regression Analyses Predicting the Recovery of Urinary Continence 1 Month After Catheter Removal in our Robot-Assisted Radical Prostatectomy Series with Perioperative Variables

	Multivariate
Perioperative variables	Univariate P value	Coefficient	Odds ratio	95% CI	P value
Age	0.4357	0.018	1.018	0.930–1.037	0.5196
Serum PSA level (ng/mL)	0.7847	0.006	1.006	0.969–1.045	0.7449
Body mass index (kg/m2)	0.4542	0.061	1.063	0.927–1.220	0.3822
Surgeon experience	0.0006	0.004	1.004	0.987–1.004	0.3085
Surgical procedure
Nerve-sparing procedure	0.1827	0.810	2.248	1.037–4.878	0.0402
Approach of bladder neck preservation	<0.0001	0.627	1.872	0.843–4.149	0.1234
Bladder neck reconstruction	0.0056	0.223	1.250	0.330–1.942	0.6225
Anterior reconstruction	<0.0001	0.264	1.302	0.370–4.587	0.6813
Rocco posterior reconstruction	<0.0001	2.709	15.01	3.413–66.67	0.0003

CI=confidence interval; PSA=prostatic specific antigen.

We indicated the difference of continence rates by applied surgical techniques, which proved significant in multivariate analysis, in Table 3. The continence rate without the Rocco PR was less than 20.0%. When we applied the Rocco PR technique in RARP, the continence rate improved to 67.1%. Furthermore, when we applied both the Rocco PR and NS techniques, the continence rates at 1 month following surgery were extremely high (85.3%).

Table 3.

Continence Rates by Applied Surgical Techniques

Rocco PR	NS procedure	n	Continence rate (%)
−	−	16	18.8
−	+	23	17.4
+	−	85	67.1
+	+	75	85.3
Total		199	64.3

PR=posterior reconstruction; NS=nerve sparing.

Discussion

Urinary incontinence is considered one of the most disturbing drawbacks after radical prostatectomy. Many urologists have attempted to investigate and have adopted several surgical techniques during radical prostatectomy to minimize the rate of incontinence and particularly to shorten the time to continence recovery. The etiology of urinary incontinence after radical prostatectomy has been attributed to various factors, such as patient age, detrusor dysfunction (decreased sensitivity and overactivity), insufficiency of the sphincter mechanism, and decreased urethral sensitivity.²⁴

BNP technique adopted during transection between the prostate and bladder has been reported by some to be correlated with earlier recovery of urinary continence.^25
–27 Klein²⁵ was the first to suggest that modification of bladder neck resection and reconstruction at the time of radical retropubic prostatectomy might influence urinary control. Selli and associates⁸ reported that BNP during radical prostatectomy does not improve the long-term results of urinary continence but does contribute substantially to its earlier recovery, thus improving QoL. In contrast, Srougi and colleagues²⁸ reported that BNP during radical retropubic prostatectomy does not improve urinary continence and that the external sphincter appears more important for continence after radical prostatectomy. We used two different BNP technique approaches—anterior resection and lateral resection; however, in the present study, the BNP approach was not an independent factor predictive of urinary incontinence 1 month after catheter removal.

Regarding the PR technique, Walsh and coworkers²⁹ published the first report of PR in 1990 in which they could achieve 73% continence rate 3 months after prostatectomy with PR vs 42% continence rate in a control group without PR. In 2006, Rocco and colleagues¹⁵ reported a new version of PR adding two modifications to the PR method of Walsh and associates.²⁹ One is to reconstruct the continuous plane of the musculofascial plate by fixing the medial dorsal raphe to the Denonvilliers fascia and then pulling up the medial dorsal raphe cranially by fixing it behind the bladder. The other modification is to make this reconstructed layer and the layer of vesicourethral anastomosis as two completely separated layers. This PR technique is what we know now as the Rocco stitch. They compared 161 cases in which PR was performed with 50 control cases and achieved the continence rates of 72% 3 days after the removal of the catheter and 78.8% after 30 days by adopting this PR technique for open radical prostatectomy. They have also demonstrated similar continence rates in their laparoscopic as well as RARP series using the same technique.^12,13

After the first report by Rocco and coworkers,¹⁵ PR has been evaluated in various institutions, but its effectiveness has not yet been under debate. In 2008, Nguyen and associates¹⁶ compared 32 cases with PR and 30 control cases without PR in robotic prostatectomy. PR group showed significantly higher continence rates on 3 days and 6 weeks after the catheter removal when compared to the control group, and average membranous urethral length measured by transrectal ultrasonography was 2 mm longer in the PR group compared with the control group. Thus, they reported that the position of the external sphincter muscle was closer to the preoperative original position by PR and concluded that the Rocco stitch is useful.

Coelho and colleagues¹⁷ compared 330 control cases and 473 PR cases and reported that the continence rate was significantly higher in PR group at 1 and 4 weeks after catheter removal. They concluded that PR is useful. Their way of PR added some modifications to the Rocco stitch—namely, putting stitches through the urethral and bladder mucosa at the second layer of PR; also, they performed AR. They stated that because of these changes, they could not simply compare their results with the Rocco stitch.

Contrary to these reports, in 2008, Menon and coworkers¹⁸ first reported the results of a randomized study for evaluating PR. They compared a single layer group only with regular anastomosis and a double layer group with PR. Regardless of the definition of continence, PR did not significantly contribute to the continence rate. They reported that the risk of cystographic leak, however, was significantly reduced in double layer group. Reacting to this article, Rocco and Rocco³⁰ pointed out that the operative method of PR performed by Menon and associates¹⁸ was a single layer reconstruction, which was partly different from the original Rocco PR. They commented that the second layer of PR is actually important and stated that, by this second layer, functional urethral length is improved and also the position of the external sphincter could be returned to its preoperative original position. As such, the lack of the standardized PR technique may obscure the ability of the Rocco PR to improve the early recovery of urinary continence after radical prostatectomy. Indeed, most of the centers modified the original Rocco's PR technique, and only a few studies used the same PR technique as that of Rocco and associates.¹⁵

The importance of the NS procedure for recovery of urinary continence after radical prostatectomy was reported by some authors.^24,31,32 Burkhard and coworkers²⁴ reported that an attempted NS procedure was the only statistically significant factor influencing urinary continence after open radical retropubic prostatectomy and concluded that NS should be tried in all patients if oncologic surgery principles are not compromised. Takenaka and colleagues³³ performed cadaveric dissection to demonstrate that the neurovascular bundle (NVB) contained many nerve fibers that innervate the cavernous tissue as well as the urethral sphincter, and furthermore, using intraoperative electrical stimulation, they revealed that the NVB contains nerves that supply the membranous urethra responsible for urinary continence. Based on these anatomic and electrophysiologic findings, they concluded that this may explain the positive impact of the NS procedure on postoperative urinary incontinence.³⁴

In the present study, the NS procedure was not a significant factor for early recovery of urinary continence in univariate analysis; however, in multivariate analysis, the NS procedure became significant after adjusting for several possible factors. The potential explanation for these statistical results is that the NS procedure may positively affect urinary continence if applied with the PR technique. As mentioned, NS may preserve the nerves that supply the membranous urethra. On the other hand, the PR technique was performed to preserve the urethral sphincteric complex in the anatomic and functional position. In these aspects, the NS procedure adding to the PR technique may strongly contribute to restoring the sphincteric function. This finding is interesting because, to our knowledge, few studies have demonstrated the correlation of the NS procedure with the PR technique.

The present study has several limitations. It was performed in a retrospective manner with a limited number of patients. Furthermore, our follow-up period was relatively short, and therefore we could not evaluate the factors that influenced the time to continence. Further prospective randomized studies with larger sample sizes may validate the prognostic significance of these surgical procedures on not only the earlier recovery of urinary continence but also the time to continence.

We introduced the Rocco PR technique in our RARP series, and we attempted to completely emulate the Rocco suture layer in PR. We achieved excellent continence rates after applying the Rocco PR technique, and when we applied the NS procedure as well as the Rocco PR, extremely high continence rates (85.3%) were observed. Moreover, we revealed that surgeon experience was not a significant independent factor predictive of early recovery of urinary continence in our RARP series. These results suggest that the higher continence rates could be achieved if the Rocco suture layer in the PR technique was precisely maintained, even in a small-volume RARP center.

Conclusions

The Rocco double-layered PR and attempted NS procedure were the only independent factors that predicted early recovery of urinary continence 1 month after catheter removal in our RARP series. The NS procedure had a positive effect on recovery of urinary continence only when applied with the PR technique. Based on these results, we recommend that these two surgical techniques, if applicable, be performed to improve patients' QoL after RARP, although further randomized, prospective studies that compare several surgical techniques are needed to verify our results.

Footnotes

Disclosure Statement

No competing financial interests exist.

Abbreviations Used

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