A Simple Reconstruction of the Posterior Aspect of Rhabdosphincter and Sparing of Puboprostatic Collar Reduces the Time to Early Continence After Laparoscopic Radical Prostatectomy

Abstract

Background:

Incontinence is a drawback after radical prostatectomy for prostate cancer. Several surgical methods to improve continence have been described however with contradictory results.

Objective:

To determine whether a modified surgical technique during laparoscopic radical prostatectomy (LRP) improves postoperative continence.

Patients and Methods:

This is a prospective nonrandomized study with two consecutive series of 100 patients in each group. The first group from 2005 to 2008 underwent a standard LRP. The second group from 2009 to 2011 was subjected to a modified LRP by sparing of puboprostatic ligaments, including the preservation of arcus tendineous, and using a simple posterior tension-releasing suture adapting the urethra stump to the bladder before the anastomosis. The patients had the same preoperative work-up and comparable preoperative baseline characteristics. The 2-year follow-up of the patients included a continence questionnaire and International Prostate Symptom Score (IPSS). Urinary peak flow (Qmax) and post-void residual (PVR) volume were assessed at 3 months. Continence was defined as 0–1 pad/day.

Results:

Only 99 patients were evaluated in each group. The patients had comparable operative characteristics. The continence rates after the modified technique vs the standard were 33% vs 16%, p=0.007 at 1 month; 66% vs 44%, p=0.002 at 3 months; 81% vs 67%, p=0.034 at 6 months; 92% vs 80%, p=0.024 at 12 months; and 95% vs 86%, p=0.05 at 2 years. No significant differences were found regarding voiding functions, the Qmax, the PVR volume, or the IPSS. Three patients developed urethral stricture in the standard group compared with none in the modified group. The negative margin rates were unchanged.

Conclusions:

The anterior preservation and posterior suture technique studied is a simple, safe, and efficient method to shorten the time to continence after LRP without adverse effects on voiding or compromising the margin rates.

Introduction

Prostate cancer is the most common cancer in men in Sweden, and the number of diagnosed cases has increased significantly over the last 10 years. In the early stages prostate cancer is treated with surgical intervention or curative radiotherapy. Surgery is the first choice of treatment in patients with non-advanced localized, non-metastatic prostate cancer and a long expected survival. Although surgery is considered to be beneficial regarding development of the disease, patients can suffer by postoperative incontinence, micturition disorders, and erectile dysfunction. For 20 years, open surgery has been the gold standard. Laparoscopic radical prostatectomy (LRP) was first described by Schuessler et al. in 1997¹ but it was developed into a standardized method by Gaston and the Montsouris team, who presented the first series.^2,3 The minimally invasive technique certainly reduced the surgical trauma with short hospital stay, less blood loss, and shorter recovery time, but the incontinence rates were still significant. Studies show that postoperative incontinence impairs quality of life (QoL) and also that it is perceived as an even worse side effect than erectile dysfunction.⁴ The time to continence is therefore of utmost importance, and different more or less complicated methods have been developed to reduce incontinence. The purpose of this study is to evaluate a simple surgical technique under LRP, intended to improve continence postoperatively while also observing possible negative differences regarding the direct surgical margin status and the lower urinary tract symptoms (LUTS) and voiding function postoperatively.

Patients and Methods

This study is a prospective outcome analysis of two consecutive cohorts, each one consisting of 100 patients who underwent LRP at the Surgical Department at the Central Hospital of Karlstad, Sweden. The team had more than 5 years of experience of 20–30 LRP per year prior to the study. The first group, from October 2005 to November 2008, was subjected to a standard LRP, while the second group from January 2009 to July 2011 had the modified operation. All operations were performed by the same team. All patients had the same preoperative work-up with digital rectal examination, determination of serum prostate-specific antigen (PSA), transrectal ultrasound (TRUS)–guided core biopsy of the prostate, and TRUS volume measuring of the prostate. The criteria for surgery were prostate cancer patients with clinical stage T1c–T3a, Nx M0, regardless Gleason sum, life expectancy >10 years, BMI below 35, age up to 75 years, American society of anesthesiologists (ASA) preoperative assessment score one to three, and no contraindication for laparoscopic surgery. The data were prospectively registered in a customized database and retrospectively analyzed. The ethics committee approved the study and the patients provided informed consent. The groups were comparable regarding the preoperative characteristics with one exception; the group with modified surgery had a significantly higher Gleason sum (Table 1).

Table 1.

Baseline Characteristics

Variables	Standard group	Modified group	p-Value
Patients (n)	99	99	–
Age, years; mean (SD)	62.75 (5.7)	63.43 (5.2)	0.380
BMI, kg/m²; mean (SD)	25.755 (2.43)	25.855 (2.34)	0.769
PSA total, ng/mL			0.667
Median (IQR)	6.7 (6.0)	7.2 (5.8)
Gleason sum biopsy (%)			0.003
5	1	1
6	67	45
7	29	52
8	2	1
Clinical stage (%)			0.157
T1c	52.5	39.4
T2	43.4	53.5
T3	4	7.1

IQR=interquartile range; PSA=prostate-specific antigen; SD=standard deviation.

Surgical procedure

The standard Montsouri technique for transabdominal LRP was used, including the posterior release of the seminal vesicles and division of the vasa deferentia with a retrovesical dissection.

The standard group was subjected to a standard LRP with complete bilateral division of the arcii tendineii to reach the holes on both sides of the puboprostatic ligaments to facilitate the ligation of the dorsal vein plexus. The dorsal vein plexus was divided near the puboprostatic ligaments. The urethra was divided sharply in order to avoid any thermal injury to both the rhabdosphincter and surrounding muscles and nerves, and to try to acquire the maximal urethral length. After the prostatectomy the anastomosis between the bladder and the urethra was performed with a running suture using a resorbable monofilament.

The modified group underwent basically the same procedure but with two distinct modifications. First, the apical dissection of the prostate spared bilaterally the apex near arcus tendineous, but still the dorsal vein plexus was ligated at the level of the puboprostatic ligaments and avoiding dissection of the structures surrounding the urethra (Fig. 1). Second, a simple posterior reconstruction was performed using a single suture with resorbable polyfilament starting 5–7 mm from the urethra, taking a big bite of the distal Denonvilliers' fascia and then one firm bite to the retrotrigonal layer of the bladder about 5–7 mm proximal to the bladder neck and adapting the structures (Fig. 2). Thereafter the anastomosis was easily performed without tension using a resorbable monofilament suture.

FIG. 1.

Preservation of puboprostatic collar by sparing of arcus tendineus bilaterally (a) and avoiding dissection of the structures surrounding the urethra (b). The standard operation included cutting the arcus tendineus (c) and dividing the dorsal vein plexus distally near the puboprostatic ligaments (d).

FIG. 2.

The posterior reconstruction was performed by suturing the rectoprostatic ligament to the posterior aspect of the bladder neck using one single stitch.

Data collection

Operative characteristics such as operation time, blood loss, whether or not the operation was nerve sparing, whether pelvic lymph node dissection was performed, hospital admission days, number of drainage and catheter days, pathological stadium (pT), and surgical margin status were consecutively collected to the customized database.

To evaluate the continence, a standard self-assessed questionnaire was administered and collected by our urotherapists to assess the continence and the need for pads or diapers at 1, 3, 6, 12, and 24 months postoperatively. To identify unwanted effects on voiding the degree of LUTS, the International Prostate Symptom Score (IPSS) questionnaire with QoL was used at 3, 6, and 12 months. The urinary peak flow (Qmax) and post-void residual (PVR) were assessed at the 3-month control. The need for surgical intervention for anastomosis stricture was registered.

One patient in the first group was excluded because of non-prostate cancer in the pathological analysis, while one patient in the second group deceased before any follow-up. The missing data regarding continence rates were three patients at 1 month, five at 3 months, two at 6 months, and none at 12 months for the standard group, and for the modified group one, none, none, and two, respectively. IPSS missing data are 31% at 3 months, 9% at 6 months, and 9% at 12 months for the standard group, and 11%, 8%, and 8%, respectively, for the modified group. Regarding the Qmax and the PVR, the data missing is 34% for the standard group compared with 23% for the modified group.

Statistical analysis

To calculate the sample size, continence rates were observed from five similar studies 3 months after radical prostatectomy.^5

–9 The groups that underwent modified surgery for continence vs standard surgery had average continence (0–1 pads) results of 82% and 56%, respectively. The mean figure of improvement from continence surgery was 46%. Our own experience prior to this study was that about 50% were continent after 3 months and 80% at 12 months. Our hypothesis was that we would improve our results by around 50%, which would be clinically important.

This study was designed to have a 95% power to show a 50% improvement 3 months postoperatively. For this, 95 patients per group were needed. Therefore the number of 100 patients in each group was chosen.

Categorical variables were compared with Fisher's exact test. For continuous parameters that were normally distributed, an independent sample t-test was used, and for continuous non-normally distributed parameters, the Mann–Whitney U-test was used. Mean values are presented with standard deviation (SD) and median values with interquartile range (IQR). The significant difference is defined as p<0.05.

Results

The operation time, blood loss, frequency of nerve sparing and lymph node dissection during operation, fraction of positive margins, hospital stay, days with drainage, and pathological stage were comparable (Table 2). The mean time with indwelling catheter was 2 days shorter in the modified group but this reflects a change of policy.

Table 2.

Operative Characteristics

Variables	Standard group	Modified group	p-Value
Operation time, minutes; mean (SD)	221 (56)	207 (52)	0.063
Blood loss, mL			0.226
Median (IQR)	200 (300)	175 (200)
Nerve sparing			0.474
Unilateral	31	32
Bilateral	4	8
No	64	59
Pelvic lymph nodes			0.636
Dissection (%)	26.3	30.3
Positive margins (%)	23.2	26.3	0.742
Admission days			0.232
Median (IQR)	2 (1)	2 (1)
Catheter, days			0.000
Mean (SD)	14.45 (2.5)	12.34 (3.0)
Drain days (SD)	1.44 (1.15)	1.42 (1.72)	0.949
Pathologic stage, n			0.64
PT2	67	71
PT3	32	28

Patients who underwent the modified LRP with the continence-preserving technique had better urinary control than after the standard LRP. The continence rates (0–1 pads) after the modified technique were 33% at 1 month, 66% at 3 months, 81% at 6 months, 92% at 12 months, and 95% at 2 years, compared with 16%, 44%, 67%, 80%, and 86% at 2 years, respectively, for the standard technique (Table 3 and Fig. 3). At all measuring points the first year, there was a significant difference between the two groups in favor of the modified group.

FIG. 3.

The use of 0–1 continence pads at 1, 3, 6, 12, and 24 months for the modified and the standard groups.

Table 3.

Postoperative Use of 0–1 Pads/Day

Months postoperatively	Standard group n (%)	Modified group n (%)	p-Value
1	15 (16)	32 (33)	0.0071
3	41 (44)	65 (66)	0.0024
6	65 (67)	80 (81)	0.0343
12	79 (80)	89 (92)	0.0237
24	85 (86)	94 (95)	0.0512

Even the true continence rates (0 pads) improved significantly up to 2 years using the modified technique (Table 4 and Fig. 4).

FIG. 4.

No need of continence pads at 1, 3, 6, 12, and 24 months for the modified and the standard groups.

Table 4.

Postoperative Total Continence, 0 Pads/Day

Months postoperatively	Standard group n (%)	Modified group n (%)	p-Value
1	9 (9)	16 (16)	0.1985
3	21 (22)	42 (42)	0.0035
6	40 (41)	61 (62)	0.0065
12	57 (58)	73 (75)	0.0103
24	60 (61)	80 (81)	0.0028

The median IPSS and QoL during the follow-up not differ significantly between the groups (Table 5). An evaluation of the voiding function at 3 months revealed a median Qmax of 19.6 mL/s for the modified group and 19.5 mL/s after standard LRP. The median PVR was 7.5 mL for the modified group but 1.5 mL for the standard group. These results did not differ significantly between the groups (Table 5). Three patients in the standard group underwent surgical intervention for stricture of the vesico-urethral anastomosis, compared with none in the modified group.

Table 5.

Voiding Functions

n/Median (IQR)	Standard group	Modified group	p-Value
IPSS 3m	4 (6.8)	4 (5)	0.784
QoL 3m	2 (2.0)	1 (2.0)	0.21
IPSS 6m	3 (3.9)	3 (4.0)	0.56
QoL 6m	1 (2.0)	1 (1.0)	0.195
IPSS 12m	3 (4.0)	2 (4.0)	0.738
QoL 12m	1 (1.0)	1 (1.0)	0.734
Qmax (mL/s)	19.5 (19.5)	19.6 (16.3)	0.257
PVR (mL)	1.5 (19)	7.5 (28)	0.178

IPSS=International Prostate Symptom Score; Qmax=urinary peak flow; QoL=quality of life; PVR=post-void residual.

Discussion

Prostate cancer was initially surgically treated by open retropubic radical prostatectomy followed by minimal-invasive techniques, such as LRP and robot-assisted radical prostatectomy. Despite the obvious benefits of the minimal-invasive surgery, such as fewer hospital days, less post-surgical pain, less blood loss, and so on, there was initially no advantage concerning the post-prostatectomy urinary incontinence.^10,11

The external urethral sphincter (EUS) is responsible for continence. It consists of straight muscle fibers, also called the rhabdosphincter. It is speculated that incontinence is due to a shortening of the sphincter's anatomical and functional length that occurs after prostate removal. In addition, the absence of support of the posterior aspect of the sphincter leads to a caudal traction of the vesicourethral anastomosis and poor urinary control. Looking at other anatomical aspects, the sphincter's front wall is twice as long as the rear, although they are of comparable thickness.¹² Other factor thought to play a role in incontinence is injury to the innervation of the EUS, namely, the end fibers of the endopelvic branch of the pudendal nerve and damage to its fascial attachments, parts of which are the puboprostatic ligaments, arcus tendineous, and the muscles of the pelvic floor, such as musculus puboperinealis and musculus levator ani.⁴ The type of surgery may also affect the continence rates, for example, a non-nerve-sparing surgery that involves larger surgical margins, or thermal exposure with iatrogenic injury in the surrounding structures.

Surgical techniques intended to shorten the time to continence have been developed in recent years, one of the most popular being the restoration of the posterior aspect of the urethra sphincter prior to vesicourethral anastomosis, by Rocco and coworkers in 2006 during open retropubic prostatectomy.⁸ This is done by reconstructing the posterior wall of the rhabdosphincter to the remaining Denonvilliers' fascia, whereafter this area is sutured to the posterior bladder wall, 10–20 mm below the new bladder neck, thus avoiding caudal traction and improving postoperative continence.^12,13 This so-called “Rocco suture” is well described and has been studied and adopted by many surgeons both in open and laparoscopy- and robot-assisted surgeries and in combination with other continence techniques, significantly improving the continence rates.^5

–9 The Pagano principle is based on reinforcing the bladder neck by constructing a thick muscle plane by suturing the lateral Detrusor flaps in the posterior midline.¹⁴ In 2008, Tewari et al. described a total reconstruction of the vesico-urethral anastomosis, where for the posterior reconstruction one single-knot suture was used, achieving, in a way, both Rocco's and Pagano's combined results. The suture started 10–20 mm from the urethral stump and then entered the retrotrigonal layer, two bites proximally and two bites distally.¹⁴ The advantage of the latest technique is that it is simpler, less time consuming, and equally efficient. Other surgeons have tested various other surgical continence-preserving techniques; some of which are anterior reconstruction, total reconstruction, sparing of the puboprostatic collar, puboperineoplasty, and combinations of the above techniques.¹⁵

On the other hand, some studies have not been able to prove better continence rates with the posterior musculofascial reconstruction concept, such as a randomized clinical trial of 94 men that yielded no significant statistical difference 3 months post-prostatectomy¹⁶ or a cumulative meta-analysis of several articles that revealed that the posterior musculofascial reconstruction is associated with only a small advantage in urinary continence recovery 1 month after robot-assisted radical prostatectomy.¹⁷ The just-mentioned results suggest that the subject in this study is controversial and further focus on the question is important.

Based on the above continence surgical techniques and our experience, we tried ways of simplifying the modifications to hasten the return to continence. The first was an apical dissection in order to preserve anterior suspension of the urethra by sparing the lateral strings of arcus tendineus and the puboprostatic ligaments. This approach minimized the trauma to the tissues surrounding the urethral stump but it also simplified and thus hastened the surgery. Thus, an anterior reconstruction was not needed. The second modification is a simple posterior reconstruction similar to Tewari's technique, but using only one single but stable suture from the distal Denonvilliers' fascia to the retrotrigonal layer of the bladder. The technique is performed in a matter of minutes, achieving not only the advantages previously mentioned but moreover facilitating a less time-consuming, tension-free suturing of a tight vesico-urethral anastomosis.

The continence rates were significantly better in the modified group, with a peak difference at 3 months, 50% improvement, and the smallest difference at 12 months, although it was still statistically significant. Total continence improved up to 2 years after surgery.

Hypothetically the new technique with a suture from trigonal area and near the urethral stump could have negative effects on the voiding function but we could not find any such disadvantage. The risk of stricture formation of the anastomosis seems to decrease after the modified procedure. There were three patients in the standard group with stricture of the anastomosis, while there were none in the modified group. This could support the hypothesis that reinforcing the urethra posteriorly makes it easier to acquire a dense and tension-free vesicourethral anastomosis.

An obvious strength of the present study is that all the operations were performed by the same surgical team with more than 5 years of experience of LRP preceding the study, resulting in a standardized surgical technique for both groups. The study included two consecutive series with comparable baseline characteristics without any exclusion or other selection. Moreover, patients were followed up for 2 years, which is a longer period of time than a majority of similar studies.

A weakness of study is that it is a non-randomized cohort study with two consecutive series. On the other hand, the operative characteristics are comparable between the two groups, indicating that the basic surgical procedure had passed the learning phase. The slightly lower operation time (14 minutes) is considered to be a benefit from the procedure itself even if it can be partly is explained by a never-ending learning curve. No significant differences were found regarding the positive margins, indicating that the primary surgical oncological outcome was not compromised by the procedure.

We consider the continence improvements as result from both the changes in the surgery but which part has the most importance is still an unsolved issue.

Conclusion

The surgical technique with preservation of the anterior anatomical structures and a simple posterior reconstruction now evaluated seems to be a safe and simple method to shorten the time to continence return after LRP without any adverse effects on voiding or compromising the negative margin rates, thus improving the QoL.

Footnotes

Acknowledgments

The authors thank urotherapists Ewa Hellberg, Birgitta Magnusson, Maria Östmark, and Carina Lundell for their help in gathering data and thus contributing in performing this study. The study was funded by the Center for Clinical Research of the County Counsil of Värmland, Sweden.

Disclosure Statement

No competing financial interests exist.

Abbreviations Used

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