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Keywords:

  • Da Vinci robot;
  • prostate cancer;
  • robot-assisted radical prostatectomy

Abstract

  1. Top of page
  2. Abstract
  3. Introduction
  4. RARP
  5. Oncologic outcomes
  6. Continence
  7. Potency and quality of life
  8. Conclusions
  9. References

Robot-assisted radical prostatectomy (RARP) is a rapidly evolving technique for the treatment of localized prostate cancer. However, cynics point to the increasing role of market forces in the robotic revolution. As yet, Europe has not taken up RARP in large numbers and this may in part relate to the high level of expertise in laparoscopy previously gained. Furthermore, setting up a robotic program is a major undertaking for many surgical units. This article reviews the current literature on RARP with regard to oncologic, continence and potency outcomes – the so called ‘trifecta’. Preliminary data appears to show an advantage of RARP over open prostatectomy with reduced blood loss, decreased pain, early mobilization, shorter hospital stay and lower margin rates. Most intra-institutional studies demonstrate good postoperative continence and potency with RARP; however this needs to be viewed in the context of a paucity of randomized data available in the literature. There is no definitive data to show an advantage over standard laparoscopy, but the fact that this technique has reached parity with laparoscopy within 5 years is encouraging.


Introduction

  1. Top of page
  2. Abstract
  3. Introduction
  4. RARP
  5. Oncologic outcomes
  6. Continence
  7. Potency and quality of life
  8. Conclusions
  9. References

Robotic assisted radical prostatectomy (RARP) is the commonest robotic procedure worldwide, particularly in the USA where there are currently more than 400 da Vinci robotic systems in operation. While RARP constituted only 10% of the total volume of radical prostatectomy carried out by American Urologists 2 years ago, it has increased to more than 60% in 2008–9. Those who are skeptical continue to argue that this is just a reflection of marketing. We can all remember a similar debate surrounding open radical prostatectomy (ORP) 10–15 years ago but now this procedure is widely regarded as the ‘gold standard’ and the only one that has been proven in a randomized trial to reduce mortality compared with watchful waiting.1

The uptake of RARP in Europe has been slower for three main reasons. First the experience gained in laparoscopic radical prostatectomy (LRP) which has yielded excellent results. Second the high costs of setting up and maintaining a robotic system. And finally the volume-outcome relationship whereby smaller centers have found it difficult to overcome their learning curves and are unable to justify investment in robotics as a result.

Despite this, surgeons experienced in both open and laparoscopic radical prostatectomy can make smooth transitions to robotics2,3 and even improve on their results. This article reviews the current literature with regard to the outcomes of RARP specifically the ‘trifecta’ of margins, continence and potency.

RARP

  1. Top of page
  2. Abstract
  3. Introduction
  4. RARP
  5. Oncologic outcomes
  6. Continence
  7. Potency and quality of life
  8. Conclusions
  9. References

The procedure is carried out with the da Vinci S HD system (Intuitive Surgical, Sunnyvale, CA, USA) (Fig. 1) and has been described elsewhere in considerable detail. The steps can be summarized as dorsal vein stitching, bladder neck dissection, athermal nerve sparing, apical dissection and vesicourethral anastomosis (Fig. 2a–e).

image

Figure 1. The da Vinci S HD surgical system (courtesy of Intuitive Surgical).

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image

Figure 2. (a) Dorsal vein stitch during robot-assisted radical prostatectomy (RARP); (b) posterior bladder neck dissection; (c) athermal left nerve sparing; (d) apical dissection; (e) vesico-urethral anastomosis.

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Oncologic outcomes

  1. Top of page
  2. Abstract
  3. Introduction
  4. RARP
  5. Oncologic outcomes
  6. Continence
  7. Potency and quality of life
  8. Conclusions
  9. References

Urologists experienced in ORP have initially found little added benefit with RARP when comparing surgical outcomes such as blood loss, hospital stay and margins in a non-randomized fashion. They have subsequently reported subtle advantages with RARP as their experience has continued to grow. Smith et al. analyzed the results of 1747 patients undergoing radical prostatectomy (RARP in 1238, ORP in 509), selecting the last 200 consecutive patients in each group. The overall incidence of positive surgical margins (PSM) was significantly lower in RARP compared with ORP (15% vs 35%) and in both groups the apex was the most common site of positive surgical margins. Patients having ORP had higher risk features, which may have influenced these results.4

Menon's team, have reported on the largest series of RARP over a 6-year period. In Detroit, 2766 consecutive men underwent RARP with up to 5-year follow-ups. The first 200 and most recent 200 patients were compared to determine the impact of experience and quality improvement. The mean surgical and robotic console time was 154 min and 116 min, respectively. Estimated blood loss was 100 mL and 96.7% of patients were discharged within 24 h of surgery. At a median follow-up of 22 months, 7.3% of men had a prostate-specific antigen (PSA) recurrence. The 5-year actuarial biochemical free survival rate was 84%. This paper confirmed that with RARP further improvements in pathologic and functional parameters can be achieved with increasing experience.5

Despite these encouraging results and the inclusion of RARP in the NICE (National Institute of Clinical Excellence, UK) guidance on laparoscopic radical prostatectomy (LRP) in November 2006, uptake of RARP in UK and Ireland has been somewhat slow. The number of da Vinci systems in these countries has increased from two in 2003 to 12 in 2008. Furthermore, setting up a robotic program is a major undertaking for many surgical units and needs considerable expertise in RRP, ORP and LRP within the team.3 In over 500 RRPs now carried out we have observed a steady drop in our PSM rate; in particular the early intraprostatic margins (resulting from inadvertent incisions into the prostate) due to lack of experience, are now rare.6 Likewise in the east, RARP is not yet well established in most centers and one has to extrapolate from comparisons between ORP and LRP. Although the anterior approach to LRP seem to be quicker,7 a positive margin rate of 36.8%8 is somewhat high compared with contemporary series. A minimally invasive approach while leading to more rapid convalescence,9,10 may yield higher PSM rates than ORP11 although this is dependent on the surgeons' experience.12

In a study of 216 consecutive RARPs by one fellowship-trained urological oncologist, the overall prevalence of PSM was 14.8% and 5.4% for pT2 cancers. The factors that were associated with a greater risk of a PSM were the serum PSA level, PSA density, pathological Gleason grade and pathological stage. The overall and pT2 PSM rate remained constant throughout the series indicating that the initial experience for RARP was not related to a greater risk of a PSM. A nerve-sparing procedure increased the risk of PSM in extraprostatic prostate cancer.13

With increasing experience RARP has been carried out as a salvage procedure after failed cryotherapy, external beam radiation and brachytherapy. We described the first case of salvage robotic-assisted radical prostatectomy for local recurrence after external beam radiotherapy in a 50-year-old man who initially underwent combined external beam radiotherapy and hormonal treatment for Stage T2a prostate adenocarcinoma. The patient was discharged on day 1 postoperatively. The histologic analysis revealed an organ-confined tumor.14 His PSA at 3 months was <0.03 ng/mL. Kaouk et al. carried out salvage RARP on four patients for biochemical failure after radiation and/or brachytherapy. The mean operative duration was 125 min, the mean blood loss 117 mL and the mean hospital stay 2.7 days. Of the four patients, three had extracapsular extension and the first two had PSM, while none had rectal injuries. Three patients were continent within a month, while one continued to use two to three pads per day at 3 weeks.15

Although most previous articles have reported the results of experienced open surgeons making the transition to RARP, recent literature indicates that the introduction of RARP to an established LRP program can also reduce the PSM rate. In a cohort study, 197 patients had LRP, and 50 patients underwent RARP. The overall PSM rate for LRP and RALP was 18% and 6%, respectively. For pT2 disease, the PSM rate was 12% and 4.7% for the LRP and RALP cohorts, respectively. For pT3/T4 disease, the positive surgical margin rate was 54% and 14% for LRP and RALP, respectively.16 A cost-benefit analysis of RARP within a high volume LRP program showed that 78 cases per year are needed to cover the costs of a purchased robot, while only 20 cases per year are needed if a robot is donated. Profit is not possible at centers carrying out fewer than 25 cases annually.17 Patient satisfaction following surgery can be assessed using a Big Five Inventory (BFI) and can depend on the individual's personality traits.18

Continence

  1. Top of page
  2. Abstract
  3. Introduction
  4. RARP
  5. Oncologic outcomes
  6. Continence
  7. Potency and quality of life
  8. Conclusions
  9. References

Experienced open surgeons have been concerned about the reduction in early continence after RARP/LRP compared with ORP.19 Similar concern has been expressed over LRP and is perhaps due to excessive traction on the urethra and surrounding pelvic floor tissues. The group from the Cleveland Clinic assessed the effectiveness of posterior reconstruction of Denonvilliers' musculofascial plate (PRDMP) in enhancing early continence after RARP and LRP. Three days after catheter removal, more patients with PRDMP were continent than those who were not reconstructed (34% vs 3%). At 6 weeks continence was again better in the PRDMP group (56% vs 17%). They found that PRDMP leads to improved maintenance of membranous urethral length and significantly higher early continence rates.20

Tewari and colleagues described the technique of hitching the bladder up to the arcus tendinus and reported early continence of 30%, 60%, 88% and 95% at 1, 6, 12, 18 weeks, respectively.21 They subsequently described total anterior and posterior reconstruction around the urethra and its relation to urethral length and continence. In 274 patients who underwent RARP sphincter lengths were measured on T2-weighted MRI images as the distance from the prostatic apex to the penile bulb. Continence was defined as zero pads or a liner only. The continence rate in the shorter sphincter group (less than 14 mm) was 47% for the control technique (no reconstruction), 81% for anterior reconstruction and 90% for total reconstruction. The continence rate in the longer sphincter group (more than 14 mm) was 80% for the control technique and 83% for anterior reconstruction and almost 99% for total reconstruction. Patients undergoing total reconstruction enjoyed earlier return of continence.22 Likewise Patel et al. have excellent continence results using a Walsh like open surgical ‘suspension suture’ supporting the urethra to the pubic symphysis.23 The key seems to be to disturb the urethra and its surrounding musculature as little as possible. There is a tendency in LRP and RARP to cause traction injury to the urethra while trying to gain maximum length to facilitate the vesicourethral anastomosis. It is also possible that the pneumoperitoneum has an adverse effect on sphincteric function. Surgeons carrying out RARP are continually looking at means of earlier return to continence. The NICE UK guidelines show no difference at one year in continence between ORP, LRP and RARP.

Potency and quality of life

  1. Top of page
  2. Abstract
  3. Introduction
  4. RARP
  5. Oncologic outcomes
  6. Continence
  7. Potency and quality of life
  8. Conclusions
  9. References

Early potency with or without a PDE5 inhibitor appears to be better with RARP when compared with ORP. With bilateral extended nerve sparing, the so called ‘Veil of Aphrodite’, 80–90% of patients can eventually achieve intercourse.24 This indicates that perhaps the better vision and more versatile tools of RARP may yield better functional results25 when open surgeons translate to this technique, but longer follow-up with validated questionnaires is essential to substantiate these results. In patients with palpable and more aggressive cancer needing wide local excision, the technique of nerve advancement and end-to-end anastomosis has recently been described. A small group of patients appeared to achieve earlier erectile potency after this surgical modification to RARP.26

It is important to avoid the use of thermal energy during nerve sparing. Ahlering and colleagues had reported the deleterious effects of cautery on potency and recently updated their results in patients where either monopolar or bipolar cautery had been used for nerve sparing. At 3, 9, and 15 months only 8.3%, 14.7%, and 43.2% were potent. However at 24+ months, 50% of unilateral and 68% of bilateral nerve-sparing were potent with an average IIEF-5 of 18.4 and erectile firmness of 75% to 100% of baseline. This suggests that injury to the neurovascular bundles is generally not permanent and recovery approaches 75–100% of baseline after 2 years.27 In our own experience with athermal nerve sparing, those with unilateral nerve sparing take 6–12 months longer to recover potency than those undergoing bilateral sparing. With patience and proactive ‘penile physiotherapy’ soon after catheter removal, erections can be achieved in most previously potent patients.

The physical component of the SF12 quality of life score appears to be higher after RARP at 1–6 weeks compared with ORP but returns to baseline more rapidly after robotic surgery.28 The UCLA-PCI SF-36v2 trademark questionnaire was used to evaluate urinary and sexual quality of life before and one year after RARP. On multivariate analysis baseline urinary function was the only predictor of worsening of urinary function (OR 1.04, P = 0.003). A decrease in sexual function was predicted by baseline sexual function (OR 1.03, P = 0.0001), baseline sexual bother (OR 1.03, P = 0.005) and a technique of nerve sparing (OR 0.31, P = 0.05). The authors found that overall better baseline sexual and urinary scores are associated with better postoperative outcomes. However, the risk of a significant decrease in urinary function, urinary bother, sexual function and sexual bother is greater in patients with better baseline scores.29 This information can be very helpful in pre-operative counseling of patients.

Conclusions

  1. Top of page
  2. Abstract
  3. Introduction
  4. RARP
  5. Oncologic outcomes
  6. Continence
  7. Potency and quality of life
  8. Conclusions
  9. References

In the absence of randomized trials the outcomes of RARP compared with ORP and LRP have to be considered with a degree of caution. A meta-analysis of 19 studies with 3893 patients suggested that, compared with ORP, LRP and RARP are associated with decreased operative blood loss, decreased risk of transfusion, and similar risk of PSM.30 While an effective transition can be made from ORP and LRP to RARP, the outcomes may be as much operator dependant as technology driven.

References

  1. Top of page
  2. Abstract
  3. Introduction
  4. RARP
  5. Oncologic outcomes
  6. Continence
  7. Potency and quality of life
  8. Conclusions
  9. References