Keywords

10.1 Introduction

Benign prostatic hyperplasia (BPH) is the most common cause of lower urinary tract symptoms (LUTS) and bladder outlet obstruction (BOO) in men. The global incidence and prevalence of this pathology has increased in the past two decades. In the United States, at least 6.5 million men suffer from BPH and it has been estimated that about 1.1 billion men will be affected by 2018 around the world [1,2,3,4].

Despite recent advances in the endourological management of BPH, the treatment of LUTS caused by large prostatic adenoma (>100 g) remains a challenge. Currently, open simple prostatectomy (OSP) remains the standard treatment in this particular situation [5–6], providing not only long-term improvement of LUTS, urinary flow, quality of life (QOL), International Prostate Symptom Score (IPSS), but also decreasing post-void residual (PVR) bladder volumes and offering lower reoperation rates when compared with endoscopic treatments. Surgical techniques commonly used are the Freyer [7] (transvesical approach) or Millin procedures [8] (transcapsular approach), both with acceptable results. However, OSP has also been associated with high rates of urosepsis, reoperation, perioperative transfusion and prolonged length of hospital stay [9,10,11].

In 2002, Mariano et al. [12] described the laparoscopic simple prostatectomy (LSP) technique , combining the benefits of OSP with the potential advantages of a minimally invasive approach, such as decreased blood loss, shorter hospital stay, reduced postoperative pain and a shorter recovery time.

Years later in 2008, Sotelo et al. [13] published the first series of robotic-assisted simple prostatectomy (RASP) , describing seven patients undergoing suprapubic transperitoneal transvesical approach with reasonable outcomes. Although attractive, the RASP was classified as an experimental procedure in 2010 by the American Urological Association (AUA) [5], considering that there were insufficient data on which to base treatment recommendations [5, 14]. Since then, additional series of RASP have been described in the literature and the procedure is being more commonly performed in men suffering from significant LUTS associated with large prostates.

10.2 Objective

This chapter aims to describe robotic-assisted simple prostatectomy, the perioperative outcomes and its role in the treatment of BPH.

10.3 Indications

The current indications of RASP are similar to traditional indications of open simple prostatectomy [15]:

  • Large prostate (over 100 g);

  • Acute urinary retention;

  • Bladder outlet obstruction refractory to medical therapy;

  • Bladder outlet obstruction with diverticulum;

  • Recurrent hematuria due to BPH;

  • Upper tract changes secondary to BOO;

  • Bladder calculi.

10.4 Surgical Technique

The use of robotic technology for prostate surgery is well established in radical prostatectomy. It offers the additional advantages of magnified binocular three-dimensional visualization, motion scaling with tremor filtration, improved surgical ergonomics and miniature wristed articulating instruments with seven degrees of freedom. Those benefits can be also extrapolated to RASP.

Below we describe the main steps of transperitoneal RASP; tips and tricks based on our personal experience are highlighted.

10.5 Patient Position and Port Placement

After induction of general anesthesia, the patient is placed in lithotomy position at a steep Trendelenburg angle with padding of pressure points, identical to a RARP procedure. We use a bean bag for adequate patient positioning and fixation to the surgical table (Fig. 10.1).

Fig. 10.1
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Patient position on the table

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A 18 Fr Foley catheter is inserted into the bladder and 6 ports are placed across the lower abdomen: typically a camera port just above the umbilical scar, three 8-mm arm ports, a 12-mm assistant port in the right flank and a 5 mm for the suction in the right upper quadrant (Fig. 10.2).

Fig. 10.2
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Port placement for RASP procedure

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10.6 Dissection of the Retzius Space and Apical Dissection

The anterior peritoneum is incised; the dissection progress laterally to the level of the vas deferens bilaterally. After this, the fat over the prostate and prostate-vesical junction is dissected to expose the bladder neck. The endopelvic fascia is then opened immediately lateral to the reflection of the puboprostatic ligaments bilaterally. The Dorsal Venous Complex (DVC) is ligated using a 12-in monofilament polyglytone suture on a CT-1 needle [15, 16]. These last two steps are not essential and the surgery may be performed safely without them [17]. However, in our personal experience DVC ligation appears to decrease bleeding during the anterior dissection of the adenoma without compromising functional outcomes.

10.7 Prostate Adenoma Access

The prostate adenoma may be accessed in different ways. We prefer to perform a 1–2.5 cm transverse incision in the anterior vesicoprostatic junction [17, 18], similar to the anterior bladder neck dissection performed in a RARP; this approach allows easy identification of the plane between the adenoma and the surgical capsule of the prostate without injuring the urethral sphincter and the neurovascular bundle (Fig. 10.3). Another approach is the transvesical technique which can be performed through a proximal horizontal cystostomy [13, 18]. A vertical cystostomy at the dome of the bladder [19] or a midline incision across the prostatic capsule and bladder neck can also be performed [12]. In all the described situations, a good exposure of the adenoma is obtained and there is no evidence that one technique is superior to the other. The decision on what approach to use is mainly based on the surgeon’s personal experience (Fig. 10.4).

Fig. 10.3
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Transverse incision in the anterior vesicoprostatic junction, with easy identification of the adenoma

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Fig. 10.4
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Different approaches to access the prostate adenoma: (a) transcapsular, (b) horizontal cystostomy, (c) midline incision across the prostatic capsule and bladder neck and (d) vertical cystostomy at the dome of the bladder (transperitoneal view)

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10.8 Dissection of Prostate Adenoma

We usually perform a horizontal incision at the level of the anterior bladder neck. The plane between the adenoma and the prostatic capsule is then identified and incised over the posterior bladder neck; the adenoma is dissected using a combination of cautery and blunt dissection. This dissection should start posteriorly, preventing blood spillage from the anterior dissection into the posterior plane. The adenoma is then mobilized from the capsule anteriorly and laterally (Fig. 10.5). A 0-Vicryl stay suture can be used for counter traction of the prostate adenoma during the dissection. Finally, the prostatic urethra is carefully transected, avoiding injury to the urinary sphincter, and the adenoma finally is removed (Fig. 10.6). Two 2-0 monocryl sutures are placed at 5 and 7 o’clock positions in the vesicoprostatic junction for additional hemostasis. Hemostasis is revised and bleeding vessels are cauterized or ligated with absorbable sutures.

Fig. 10.5
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Prostatic adenoma being dissected laterally (a) and anteriorly (b)

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Fig. 10.6
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Prostate adenoma being removed after section of the prostatic urethra

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10.9 Reconstruction: Advancement of the Bladder Neck Mucosa/Vesico-urethral Anastomosis

In the classical “trigonization” technique the mucosa of the posterior bladder neck is then advanced to the distal urethral mucosa using two figure-of eight 2-0 Vicryl sutures or using a continuous 3-0 monocryl suture [20]. The idea is to reapproximate the mucosa in order to reconstruct the anatomy of the prostatic fossa and promote hemostasis. We have recently described a modified reconstruction technique [16] which includes three surgical steps: plication of the posterior prostatic capsule, modified van Velthoven continuous vesico-urethral anastomosis and suture of the anterior prostatic capsule to the anterior bladder wall. In this approach, after the resection of the adenoma, the posterior capsule is plicated using two 12.5 cm 3-0 monocryl sutures (on RB 1 needles) tied together. The proximal edge of the capsule is approximated to the distal capsule using one arm of the continuous suture. The posterior bladder neck is then sutured to the posterior urethra using the other arm of the suture. A continuous modified van Velthoven vesico-urethral anastomosis is then performed. Two 20-cm 3-0 monocryl sutures of different colours (on RB 1 needles) are tied together with ten knots to provide a bolster for the anastomosis. The posterior part of the vesico-urethral anastomosis is performed with one arm of the suture, in a clockwise direction, from the 5 to 9 o’clock positions. This step is followed by completion of the anterior anastomosis with the second arm of the suture, in counterclockwise fashion (Fig. 10.7). This modified technique of RASP has potential advantages in our experience: reduced blood loss, lower blood transfusion rates, shorter length of hospital stay and no need for postoperative continuous bladder irrigation.

Fig. 10.7
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Modified technique of a vesico-urethral anastomosis for RASP procedure

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10.10 Closure

A 18F two-way Foley catheter is placed into the bladder and the balloon is inflated with 20 cc of water. Alternatively, a 3 way Foley catheter can be used and the balloon can be insufflated in the prostatic fossa in order to further promote hemostasis; however, with our technique the prostatic fossa is totally plicated and reconstructed precluding the need of this maneuver and the use of three way catheters. A Jackson-Pratt drain is placed into the rectovesical pouch. The midline camera port incision is extended and the specimen (Fig. 10.8) is extracted using an endobag. The aponeurosis is closed using a 0-Vicryl suture, and the skin is closed using a 4-0 Monocryl subcuticular suture. We do not use routinely continuous bladder irrigation as the prostatic fossa is “bypassed” by the anastomosis and the patients do not usually present any grade of hematuria in the early postoperative period.

Fig. 10.8
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Prostate adenoma weighing more than 100g

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10.11 RASP Outcomes

10.11.1 Perioperative Outcomes

Consistent data comparing outcomes between RASP, LSP and OSP for the treatment of large prostatic adenoma (>100 g) are limited. There are no randomized clinical trial (level 1 evidence). Comparisons of RASP with Holmium Laser Enucleation of the Prostate (HoLEP) or other endoscopic procedures are also lacking. The main evidence comes from two meta-analyses and multiple small case-series. Below we present data from these analyses in terms of operative time, estimated blood loss and transfusion, length of hospital stay, complications, functional outcomes, duration of catheterization and cost comparison.

10.11.2 Operative Time

In a meta-analysis [21] comparing minimally invasive simple prostatectomy (MISP) with OSP, from 27 observational studies published between 2004 and 2014, including 119 RASP cases, the mean operative time was 141 min, about 40 min longer than OSP. This was probably a consequence of different learning curves between both methods [22], as well as potential bias of including the LSP cases. In the largest exclusive RASP series to date, Pokorny [23] obtained a shorter operative time of 97 min (comparable to OSP) with a median preoperative prostate volume of 129 mL (104–180). In our initial series the mean operative time was 90 ± 17.6 min (75-120 min) with a median preoperative prostate volume of 157 mL (90–300) [16], reaffirming the importance of being familiar with the robotic technique.

10.12 Estimated Blood Loss and Transfusion

Although OSP is a generally safe procedure, it is often associated with relatively high rates of perioperative transfusion. Early RASP case series also reported high estimated blood loss (EBL), with a mean of 558 mL (150–1125 mL) in one of the early publications [24]. However, results have improved over time and RASP case series after 2008 report a mean operative blood loss of 183 mL and low transfusion rates ranging from 0 to 5% [25]; these transfusion rates are significantly lower than the 17% transfusion rates observed in OSP cases from the recent US Nationwide Inpatient Sample (NIS) [26]. This same study, using an adjusted transfusion prevalence, revealed a 50% lower transfusion rate for MISP but this difference did not quite reach statistical significance (odds ratio 0.47; 95% CI, 0.18–1.26). In another recent meta-analysis, Banapour et al. [18], reporting 109 RASP cases from eight non-comparative case series, showed a mean operative blood loss of 197 mL with a transfusion rate of 0%, adding further supportive data that RASP is associated with less blood loss and perioperative transfusion when compared to OSP.

In our series [16], the modified vesico-urethral anastomosis technique in RASP assures low EBL and low transfusion rates, with the mean EBL of 208 ± 66 (100–300) mL with a transfusion rate of 0%, in a reproducible and safe method.

Although RCTs are lacking at this time, data suggests that robotic assisted surgery leads to less bleeding and less perioperative transfusion rates.

10.13 Length of Hospital of Stay

In the NIS series, studying 6027 OSP cases and 182 MISP cases, the median stay for MISP was 2 days shorter than for OSP (2 vs. 4 days). However, this was not statistically significant (p = 0.19) probably because the analysis was underpowered [26]. In consistent RASP series, Pokorny [23] and Autorino [27] respectively showed a median length of stay of 4 days (3–5 days) and 2 days (1–4 days). In a meta-analysis [21], evaluating some case series, the length of hospital stay was significantly shorter in MISP group with 1.6 days, (95% CI: 0.2–2.9, p = 0.02) compared with OSP group with 7.6 days.

As described above, our technique can reduce the length of hospital stay by eliminating the need for postoperative bladder irrigation, with a median stay of 1 day, we have demonstrated that shorter hospital stay is possible with RASP [16].

10.13.1 Complications

Due to the variability in the methods of reporting and classifying complications, the comparison of complication rates between different series and techniques is a difficult [25], since not all papers comply with all the Martin criteria [28] for the description of postoperative complications.

In the systematic review about the issue, Lucca [21] summarizes the current data on perioperative complications (n = 114). Overall, there were no significant differences between OSP and MISP groups (OR 0.64, 95% CI 0.4–1.03, p = 0.066), as well as for each individual complication: blood transfusion (OR 0.54, 95% CI: 0.13–2.10, p = 0.386), urinary retention (OR 0.93, 95% CI: 0.39–2.15, p = 0.867), urinary tract infection (OR 0.61, 95% CI: 0.07–5.66, p = 0.066) and Re-operation (OR 1.82, 95% CI: 0.48–6.20, p = 0.382); note that this analysis is not exclusively with RASP cases as it includes also LSP.

Autorino et al. [27], evaluating 1330 MISP cases, report a low postoperative complication rate and that most of the complications in 90 days were low grade Clavien 1–2 (8.8%), which translates into minimal clinical impact on the regular postoperative course. This data supports lower complication rates than those typically seen with OSP.

In unpublished data [33], comparing HoLEP (45 cases) versus RASP (81 cases) similar complication rates with no Clavien >3 grade were found in both groups (p = 0.7).

Overall, there is a need for prospective well-designed studies to adequately assess for true differences in complication rates between different modalities.

10.14 Duration of Catheterization

Some evidence indicates that there is no difference in catheterization time between RASP and OSP [13, 16, 17, 18, 19, 23, 24]. On the other hand, a meta-analysis comparing MISP and OSP noted decreased catheter duration for MISP (weighted mean difference −1.3 days, 95% CI: 2.5 to −0.06, p = 0.04) [21]; however, the criteria for removing the catheter were not clearly stated and most likely not uniform across the different series and surgical approaches.

When RASP is compared with HoLEP the catheterization time was shorter for HoLEP group (2 vs. 4 days; p = 0.0001), however, the two groups were not statistically similar to each other [33].

In our experience, the modified technique of robotic–assisted simple prostatectomy allows a safe withdrawal of catheter at an average of 4.8 days. A cystogram is performed in all patients on postoperative day 4–6. Up to 200 mL contrast medium is instilled into the bladder under gravity. In the early publication of our modified technique, no leakage was observed [16].

To the date no substantial difference between catheter durations has been demonstrated in published RASP and OSP studies [25].

10.15 Functional Outcomes

Perioperative and short-term functional data seem similar in RASP and OSP. A retrospective study presented data about 67 RASP cases and demonstrated improvement in functional outcomes (p < 0.001) at a follow-up of 6 months [2,3,4,5,6,7,8,9,10,11,12], with a postoperative Qmax of 23 mL/s [16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35], IPSS of 3 points (0–8) and post-void residual volume of 0 mL (0–36) [23]. A meta-analysis [21] comparing MISP (including RASP cases) with OSP reported an average aggregate improvement in the maximum urinary flow rate (Qmax) of 14.3 mL/s and IPSS improvement of 17.2 points for MISP (n = 163 patients), similar to data obtained by OSP (n = 252), but the small study size, publications bias and short follow-up are limitations.

Assessing RASP versus HoLEP, both groups showed respectively an improvement of maximum flow rate (+15 vs. +11 mL/s, p = 0.7), a reduction of post-void residual (73 vs. 100 mL, p = 0.4) and improvement in IPSS (−20 vs. −18, p = 0.8) with median follow-up of 12 months in the RASP group and 5 months in the HoLEP group [33].

Using a modified technique of robotic simple prostatectomy, we obtained a significant improvement from baseline in IPSS (average preoperative vs. postoperative, 19.8 ± 9.6 vs. 5.5 ± 2.5, p = 0.01), a mean maximum urine flow (average preoperative vs. postoperative 7.75 ± 3.3 vs. 19 ± 4.5 mL/s, p = 0.019) at 2 months after RASP and all patients were continent (defined as the use of no pads) at 2 months after RASP [16]. It is important to note that no other available study reported the continence rate in its postoperative period.

Overall, these three approaches showed no differences in perioperative complication rates and consistent improvement in functional outcomes in the short to medium term [18, 26, 33], but long-term results are needed.

10.15.1 Learning Curve

Currently no papers evaluating the RASP learning curve have been published. Existing data tends to be reported by experienced surgeons. RASP using a modified technique of vesico-urethral anastomosis certainly requires a certain mastery of robotic technology, however for those surgeons who are accustomed to performing RARP, this learning is simple and safe. Therefore, we envisage that for surgeons with existing expertise in RARP, few cases in RASP are necessary to achieve reproducible and adequate results.

10.15.2 Cost Comparison

Costs related to minimally invasive technologies, especially robotic technology, remain a highly debated issue [34]. A formal cost analysis is difficult given the fact that hospital costs and reimbursement issues vary significantly between countries and healthcare systems. Certainly the high upfront and maintenance costs of a robot mean that this technology is not easily accessible to many Urological centres. However if the robot is already in place for other types of surgery then the relative costs are much reduced.

Matei [35] reported a cost of €3840 per RASP versus more than €5000 for OSP with the higher costs of OSP being due to higher hospitalization costs. They also showed that cost of bipolar transurethral resection of the prostate in the very large prostate was similar to that of RASP. TURP in the very large prostate may of course require more than one procedure and inpatient stay which may explain these findings. However, Sutherland [17] reported that the cost of RASP was higher than OSP, adding an average of $2797 to the operating charges. In this context future research should adjust the time-horizon for cost-effectiveness analyses to account for costs associated with complications, transfusion rates and hospital length of stay. Certainly the arrival of cheaper robotic systems is eagerly anticipated and may tip the cost-effectiveness ratio in favour of RASP for the very large prostate.

10.15.3 Conclusions

RASP appears to be an effective and safe treatment option for men with symptomatic BPH and large prostates (>100 g). Although prospective randomized trials comparing RASP to other treatment modalities are lacking, existing comparative series would suggest that improvements in Qmax and IPSS are similar to those of OSP. RASP may also offer lower rates of perioperative transfusion and shorter hospital admissions than OSP. Certainly, in institutions with access to the robot and where appropriate expertise in robotic pelvic surgery is available, RASP should be considered as an important treatment option for the symptomatic large prostate.