ROBOT-ASSISTED LAPAROSCOPIC RADICAL PROSTATECTOMY: ONCOLOGICAL AND FUNCTIONAL RESULTS OF 184 CASES. MOTTRIE, A., VAN MIGEM, P., DE NAEYER, G., SCHATTEMAN, P.,
CARPENTIER, P., FONTEYNE, E. Contact information: Peter Van Migem
Department of Urology OLV Hospital Moorselbaan 164 B-9300 Aalst Belgium
Tel. N° 0032/53724378
E-Mail: pvanmigem@yahoo.com

Mottrie, A.,Van Migem, P., De Naeyer, G., Schatteman, P. Carpentier, P., Fonteyne, E. : ROBOT-ASSISTED LAPAROSCOPIC RADICAL PROSTATECTOMY: ONCOLOGICAL AND FUNCTIONAL RESULTS OF 184 CASES. Seclaendosurgery.com (en línea) 2007, nº 19. Available online. http://www.seclaendosurgery.com/seclan19/articulos/art01eng.htm
ISSN: 1698-4412

Keywords : Continence, erectile function, laparoscopy, prostatectomy, prostate cancer, robotics.

Objective: To evaluate the initial functional and oncological results of 184 robot-assisted radical prostatectomies performed at our hospital.
Methods: A retrospective study was made of the first consecutive 184 robot-assisted radical prostatectomies that were performed at our hospital between February 2003 and December 2005. The procedures were performed by two surgeons using the daVinci robot with three arms. A transperitoneal approach was used in all patients. All patients had a clinically organ-confined prostate cancer (≤cT2c). The median follow-up was 6 months. 
Results: A positive surgical margin was found in 29 of the 184 patients (mean of 15.7%). The percentage positive surgical margins for the organ confined (pT2) and non-organ confined prostate cancers (pT3) was 2.5% and 38% respectively. Ninety-five percent of patients were completely continent or wore one safety liner. Forty-three percent of the continent patients achieved complete continence within 28 days. Eighty-one percent of the patients, younger then 60 years old and whom received a nerve-sparing procedure, were potent and able to perform sexual intercourse. This percent dropped to 51% in patients older then 60 years old. There were no major complications encountered.
Conclusion: The functional and oncological results of this minimal invasive procedure seem very promising. Longer follow-up of the data and larger prospective studies are necessary to confirm these promising results.

In the next 15 years, prostate cancer will most likely become the most frequent cancer in men [1]. Radical prostatectomy is standard treatment for localized prostate cancer in young patients [2]. Despite the excellent oncological results of this therapy, many patients choose alternative treatments due to fear of the invasiveness of radical surgery, the postoperative pain and the potential side effects after surgery (mainly incontinence and impotence). With the development of minimal invasive techniques, the radical prostatectomy may again become a more favorable option. The laparoscopic radical prostatectomy is performed routinely and successfully in different renowned hospitals [3-5]. Despite their promising results, this technique is still not performed routinely by most urologists because of its steep learning curve.
The robot-assisted laparoscopic radical prostatectomy (RoLRP) is the next step in the evolution of minimal invasive techniques in the treatment of prostate cancer. The daVinci surgical system (Intuitive Surgical), with its three dimensional image, endowrist instruments (articulating instruments moving in real-time) and the ergonomic seating of the surgeon in the console, makes it possible to perform complex and lengthy procedures with more ease. This makes a more meticulous dissection possible which might translate in a better functional and oncological outcome for the patient.
The technique of the transperitoneal RoLRP was described and standardized by the Detroit group under supervision of M. Menon [6-7].
In this article, we would like to present our initial oncological and functional results in the first 184 RoLRP performed in our hospital.

We performed a retrospective study of the first consecutive 184 RoLRP performed in our hospital between February 2003 and December 2005. The operations were performed by two surgeons using the daVinci robot with three robot arms.
Approximately 50 cases of conventional laparoscopic radical prostatectomy were performed by one of the two surgeons prior to using the robotic assistance. Both surgeons have extensive experience in the field of open radical retropubic prostatectomy.
The patient is placed in a dorsal lithotomy position with the lower limbs in slight abduction allowing the surgical cart to be wheeled in position between the legs. A Veress needle is placed in the left hypochonder and the abdomen is insufflated to 12mm of mercury. A 12mm camera port, two 9mm robot ports, two 5mm ports and a supplementary 12mm port is placed in a semi-circular pattern. The patient is placed in Trendelenburg position and the ports are then connected to the robot arms.
The next steps are performed in chronological order: 1. Horseshoe-shaped opening of the peritoneum starting on either side of the medial umbilical ligaments, mobilisation of the bladder and creation of the extraperitoneal space; 2. Pelvic lymphadenectomy (if necessary); 3. Incision of the endopelvic fascia and exposure of the apex of the prostate, ligation and control of the dorsal vein complex; 4. Bladder neck transection, posterior dissection with freeing both seminal vesicals; 5. Control of the lateral pedicles and preservation of the neurovascular bundles in an interfascial fashion where indicated; 6. Incision of the dorsal venous complex, freeing all periurethral tissue circular to gain urethral length and cutting the urethra few millimetres away from the apex; 7. Specimen entrapment and urethrovesical anastomosis after indwelling a 18 ch. bladder catheter; 8. The specimen is extracted through a small supraumbilical midline incision.
A patient was considered continent if he used no liner or just one safety liner for protection against the occasional loss of a few drops of urine. A patient was considered potent if he was able to perform sexual intercourse (with or without the use of a PDE-5 inhibitor).
The ‘Stanford procedure’was used to sample the prostatectomy specimen [8].

The preoperative, postoperative, oncological and functional results of our 184 patients were collected retrospectively and summarized in Table 1.
All patients had clinically organ confined prostate cancers (≤ cT2c). Non-organ confined prostate cancer was found in 37% of the definitive anatomical specimens (pT3a-b).
A positive surgical margin was found in 29 of the 184 patients (15,7%). Only 2.5% of the organ confined prostate cancers (pT2a-c) had positive surgical margins. Thirty-seven percent of the non-organ confined prostate cancers (pT3a-b) had positive surgical margins. There was detectable PSA-level in 11 (38%) of the 29 patients, with positive surgical margins, one month after surgery. These patients received salvage radiotherapy. The other patients (62%), with positive surgical margins with no detectable PSA-levels postoperatively, were placed under active surveillance.
The mean operative time was 171 minutes with a mean estimated blood loss of 200 ml. One patient (0.5%) required blood transfusion due to excessive peroperative blood loss (2500ml). The median catheter duration was 7 days. Three patients (1.6%) temporally required a new catheter. This was due to oedema around the vesico-urethral anastomosis. The catheters were removed after an additional 5 days.
Postoperative neuropraxia of peripheral nerves was seen in three patients (2 cases concerning the plexus brachialis and one case concerning the sciatic nerve). Spontaneous recuperation was seen in all patients after 48 hours.
Partial dehiscence of the vesico-urethral anastomosis was seen in one patient. This was observed after two days of initial catheter removal. The patient experienced slight discomfort in the hypogastric region and was unable to void. Cystoscopy showed a minor dehiscence of the anastomosis. The catheter of this patient was removed after 32 days.
Conversion to an open procedure was necessary in one patient due to a technical defect of the robot (mechanical failure of one of the two optical lenses).
Despite the short median follow-up of only 6 months, 175 (95%) of the patients were continent. In this subpopulation of continent patients, 17 patients (9.7%) used a safety liner for protection against the occasional loss of a few drops of urine. Nine patients (5%) still used more then one pad per day. The mean time to complete continence was 2.1 months. Forty-three percent of these patients were continent within 4 weeks.
Table 2 (A&B) summarizes the postoperative sexual function after a median follow-up of 6 months. Eighty-one percent of the patients, younger than 60 years old and whom received a nerve-sparing procedure, were potent postoperatively (thirty-five percent did use a PDE-5 inhibitor). The potency of the patients, 60 years or older and whom also received a nerve-sparing procedure, was 51% (forty-three percent used a PDE-5 inhibitor). These results, based on Chi-square, were statistically significant.
Forty-seven percent of the patients, whom received a unilateral nerve-sapring procedure, were potent. The percentage of potent patients, whom received a bilateral nerve-sparing procedure, was 70%. These results were also statistically significant.
There seems to be a relationship between the nerve-sparing technique and early recovery of continence.  Of the patients (89 pts.) who underwent a bilateral nerve-sparing prostatectomy, 49% was continent within one month, in contrast to the 31% of the non nerve-sparing group (32 pts.). The age of the patients in the bilateral nerve-sparing and non nerve-sparing group were comparable with an average age of 61.2 years and 63.4 years respectively.

Table 1. Preoperative, operative, oncological and postoperative data

DISCUSSION

Robot assisted radical prostatectomy has generated significant interest among urologists. In the year 2004, ten percent of all radical prostatectomies in the United States were performed by the daVinci robot. This increased to 20% in 2005. In the year 2006, the expectations are even greater.
Complex laparoscopic procedures are simplified by robot assistance. This results in a faster learning curve and possibly in more favourable oncological and functional results when comparing to conventional laparoscopic and open procedures.
In different studies, the percentage of positive surgical margins in organ confined tumours (pT2) after open radical prostatectomy and after conventional laparoscopic radical prostatectomy ranges between 7.8 and 27% [9-10] and 8 and 29% respectively [11-12].  Ahlering et al [13] published the oncological results of their first 140 RoLRP. In this study, the percentage of positive surgical margins in organ-confined tumours was merely 4.7%. Only 2.5% of the organ-confined tumours (pT2) in our study had positive surgical margins.
Major preoperative complications were absent in our series. If problems are encountered, conversion into open or laparoscopic prostatectomy should be considered. In our series, only one conversion to open surgery was mandatory due to mechanical failure. Conversion to open surgery or laparoscopy should be dependent on the surgeon’s experience.
We encountered temporary paralysis of the limbs due to neuropraxia in three of our patients (2 cases concerning the plexus brachialis and one case concerning the sciatic nerve). Extra safety measures are now used to protect the precarious pressure points of the patient placed in extreme trendelenburg position.
In different studies, comparing the functional results after open, conventional laparoscopic and robot radical prostatectomy, the percentage of complete continence is almost identical. This percentage varies between 80-95% after a follow-up of 12 months [14]. In our study, 95% of the patients were continent.
In a prospective non-randomized study of Tewari and Menon [15], the postoperative results of open and robot radical prostatectomies were compared. In this study, the robot group achieved continence more rapidly when compared to the open group (50% complete continence after 44 days in the robot group vs 160 days in the open group). Forty-three percent of the continent patients in our study group achieved complete continence within 28 days.
Takenaka A. et al [16] and Ficarra V. et al [17 ] also illustrated a rapid return of continence in RoLRP.
Anastasiadis and Rassweiler [18 &19] compared the functional results after open and conventional laparoscopic radical prostatectomy. They showed no significant difference in the time to complete continence in both groups. In the study of Anastasiadis [17], the time to nocturnal continence in the laparoscopic group was shorter.
The trend of a more rapid recuperation of continence after RoLRP is also projected in the potency results of Tewari and Menon. Patients after RoLRP had a more rapid return of erection (50% return of potency after 180 days in the robot group vs. 440 days in the open group) [15]. The definitive return of potency after a bilateral nerve-sparing procedure (laparoscopic or open) varies between 32 and 86% in different studies [14]. The data on the postoperative sexual function, after RoLRP, is still immature. In a few series [15, 20] that have reported on potency, +/- 80% of the patients had return of erections (with or without the use of PDE-5 inhibitors) at a mean weighted follow-up of 7.7 months.
Eighty-one percent of our patients, who were younger then 60 years old, were potent (with or without the use of PDE-5 inhibitors) and able to perform sexual intercourse. This percentage dropped to 51% in patients older then 60 years old.
Finally, especially in Europe, there is the problem of costs and reimbursement.  Purchase of a new device is 1.300. 000 to 1. 850. 000 Euro TVA inclusive, costs for maintenance about 10 % of that sum and the instruments between 1 000 and 1 500 Euro pro case. When we consider to perform 250 cases per year, the estimated cost pro case is about 2 500 Euro. In Belgium, as in most European countries, no reimbursement for robot-assisted surgery exists to date. This is in contrast with brachytherapy, where the seeds are reimbursed for 6 000 Euro. Whereas, laparoscopic radical prostatectomy may reach the cost-equivalence of open surgery, this is probably not the case for robot assisted radical prostatectomy [21].
As stated in the methods section, we performed all RoLRP via a transperitoneal approach. Different centers have recently performed the RoLRP via an extraperitoneal approach. Joseph JV and Patel HR et al [22] concluded that this new approach was feasible with good visualisation and dexterity of the robot while avoiding the peritoneal cavity. Atug F. and Davis R.[23] concluded in a randomised prospective study, comparing the extraperitoneal and transperitoneal approach in 80 patients, that both approaches produced comparable and favorable outcomes. There were no statistically significant differences founds in the results of both groups. Surgeon preference will likely play a significant role in the approach used.
We can conclude that the functional and oncological results of this minimal invasive procedure seem very promising. Longer follow-up of the data, the use of objective questionnaires to assess functional outcome and larger prospective studies are necessary to confirm these promising results.

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