ROBOTICS
THOMAS E. AHLERING, MD, DOUGLAS W. SKARECKY, BS
The development of a laparoscopic approach to radical prostatectomy has taken several years. Indeed after the initial report of 9 cases, by Schuesler, Clayman, and associates in 1997 [1], 2 to 3 years transpired before meaningful success was described by 2 groups in Paris [2,3]. This is because laparoscopic radical prostatectomy (LRP) is considered the most difficult urological procedure to master due to technical and reconstructive requirements. Although LRP enjoyed sustained growth in Europe, the rather difficult “counterintuitive” nature of the technique retarded its acceptance in the United States.
In 2001, Menon and associates failed to establish a pure LRP program at the Henry Ford Hospital but subsequently fathered the first large-scale robot-assisted LRP program [4]. This group demonstrated that the da Vinci robot (Intuitive Surgical, Inc, Sunnyvale, CA) could overcome the counterintuitive pitfalls of standard LRP surgery. Potential advantages offered by this technology include intuitive instrument handling, 3-D viewing and comfortable ergonomics, precise and facile camera positioning, plus “machine-like” precision with 7 degrees of freedom of the wristed instruments (Figures 1 and 2).
Figure 1. The user-friendly da Vinci robotic console is shown at left, and an example of positioning of the robotic arms is shown at the right of the figure.
Figure 2. Placement of port sites for a 3-arm robotic surgery: L=robot's left arm, R=robot's right arm, C=camera, Q=assistant's left and right hand ports. Reprinted from Urology, Volume 63, Lee et al, Laparoscopic radical prostatectomy with a single assistant, Pages 1172-1175, Copyright 2004 with permission from Elsevier.
However, learning (and training) the technique of robotic (laparoscopic) prostatectomy (RLP) has a substantial learning curve. Several authors have reported that the “4-hour” learning curve is for 15 to 30 cases for experienced open surgeons as reported by Menon [4], Ahlering [5], and Wiklund [6] (Figure 3). The “4-hour” learning curve for LRP has been reported to be 60 to 100 cases. Although the cost of the da Vinci robot (~$1.3 million) and per case expenses favor open and standard laparoscopic surgery, the rapid rise in interest and application of RLP leave little question of its growing acceptance by surgeons and patients. As an experienced open and robotic surgeon, there is no question that the ability to place the tip of the da Vinci 3-D camera between the rectum and prostate 1 cm to 2 cm from the apex and sharply dissect attachments is without parallel in open pelvic surgery. A potential drawback to robotics is the loss of tactile sensation. Some surgeons claim it is an important facet in determining points of extracapsular extension although data supporting the ability to feel a microscopic margin have not been demonstrated.
Figure 3. The learning curve of the UC Irvine experience in achieving 4-hour surgery times with a best-fit curve. Adapted from Basillotte et al. Laparoscopic radical prostatectomy: review and assessment of an emerging technique. Surg Endosc. 2004:18(12):1694-1711 with kind permission of Springer Science and Business Media
Factors important to both patients and surgeons include operative time, blood loss, transfusion rate, and length of hospital stay, among other things. RLP offers well-established benefits with regard to blood loss, transfusion rate, and length of stay. For example, blood loss was significantly reduced in LRP versus blood loss in open prostatectomy in 2 studies [7,8]. In my own experience, complication rates have been reduced at least 50% (2% to 4% in RLP) compared with complication rates in my open experience (9%). In most published series, complication rates range from 8% to 20% versus 4% to 10% in RLP [9].
ONCOLOGICAL CONTROL
Oncologic outcomes, such as local recurrence or metastatic progression, are primarily driven by individual tumor characteristics like preoperative PSA levels and pathological Gleason score and stage. Obviously, radical prostatectomy cannot change these factors. The primary oncologic goal of radical prostatectomy regardless of approach is to avoid inadvertent entry into the prostate in low-risk patients (pT2 positive margins), and for patients with extracapsular extension the task is to resect soft tissue margins wide enough to prevent pT3 margins. An advantage of RLP is the visual capability afforded by minimal blood loss and intimate camera positioning adjacent to the prostatic capsule. Most experienced robotic centers report in pathologically organ-confined disease (pT2), margin rates ranging from 4.5% to 16% [9,10].
QUALITY OF LIFE ISSUES
Continence
Reporting of continence rates has been needlessly complicated. Continence should be defined as urinary control requiring no pads as determined on self-administered questionnaires. It is a definitive question and when coupled with the time following surgery to achieve pad-free status allows for Kaplan-Meier analysis (Figure 4). Several RP series have reported median time to pad-free status of approximately 35 days to 45 days and a 6-month pad-free status rate of 90% [5,6]. Thanks to the innovative “single knot” urethrovesical anastomosis as described by van Velthoven [11], clinically evident bladder neck contractures in over 500 cases have been below 0.3 % (personal data).
Figure 4. Percentage of men achieving pad-free continence over time.
POTENCY
Like continence, the reporting of potency has a checkered track record. The use of validated questionnaires pre- and postoperatively (eg, IIEF-5 International Index of Erectile Function) is essential to the acquisition of believable data, which can then be used to correlate postoperative erectile function with operative technique [9]. There is no reason to believe that radical prostatectomy (regardless of approach) will make impotent men potent. Historically, the lack of use of validated questionnaires severely hinders evaluation or comparison of sexual function for RP.
In a review of an LRP series by Basilotte et al [9], 47% to 86% of men who were “potent” preoperatively had erectile function adequate for intercourse at 1.5 years of follow-up with or without 5PDE inhibitors. El-Hakim and Tewari [12] summarized the available series on postoperative sexual function in RP. In 4 centers reporting potency, 49.5% of patients had intercourse and 79% had return of erections, with or without 5PDE inhibitors at follow-up of less than 1 year. It is safe to state that definitive conclusions cannot currently be drawn.
Preservation of sexual function from a technical view has 2 components. It is critical to physically preserve the neurovascular bundle (NVB) and also limit thermal or other injury during dissection. RLP initiates the dissection at the prostatic vascular pedicles and proceeds antegrade to dissect the NVB to the apex. Generally, robotic and laparoscopic surgeons use some form of thermal energy to control the vascular pedicles. However, Ong and associates [13] have definitively demonstrated in a laparoscopic dog model the critical need to avoid thermal energy in proximity to the NVB. Although the NVB was “preserved,” thermal injury resulted in a 95% loss of corporal pressures on the involved side. Gill and associates [14] and Ahlering and associates [15] recently described the feasibility of a cautery-free technique to preserve the NVB by using laparoscopic vascular “Bulldog” clamps (Figures 5 and 6). We have already experienced dramatic improvement over our previous technique using bipolar cautery to control the vascular pedicle;16 43% vs. 8% of men (65 years and preoperative IIEF-5 of 22 to 25) have return of erectile function with the cautery-free technique at 3 months with or without 5PDE inhibitors. Menon et al [17] recently reported potency outcomes at 12 months at either 74% (conventional nerve sparing) and 97% with prostatic fascia preserved (veil of Aphrodite) for prepotent men (IIEF-5) >21 who underwent bilateral nerve sparing. Although the study did not control for bipolar cautery implicated by Ong et al [13], complete information regarding potency will require at least 2 years of follow-up.
Figure 5. Placement of a bulldog clamp on the neurovascular bundle. Reprinted from Urology, Volume 65, Ahlering et al, Feasibility study for robotic radical prostatectomy cautery-free neurovascular bundle preservation, Pages 994-997, Copyright 2005 with permission from Elsevier.
Figure 6. The interoperative placement of a bulldog clamp on the vascular pedicle. (SV=seminal vesical)
CONCLUSION
In Kuhn's classic description of science, robotic surgery is quickly progressing beyond the prenormative stage of nongeneralized methods and descriptions to a new consensus methodology. The impact of future technological advancements favors the robotic interface and perhaps a new surgical paradigm. Platforms are being explored for preoperative or real-time imaging, or both, of structures (ureters, arteries, nerves, prostatic capsule, and others) for immediate intraoperative feedback. Remote training or proctoring is another promising application. The future may already be evident. In 2001, 247 procedures were performed. In 2002, 2003, 2004, and 2005; 766, 2648, 8642, and 16,000 robotic procedures were performed, respectively. For 2006, the projection is 25,000 of an estimated 100,000 in the United States (personal communication from Intuitive Surgical Inc.).
Figure 7. View of the neurovascular bundle during dissection of the prostate.
Address reprint requests to: Thomas E. Ahlering, MD, Professor of Urology, University of California, Irvine, 101 The City Dr South, Bldg 26, RT 81, Orange, CA 92868, USA. Telephone: 714 456 6703, E-mail: tahlerin@uci.edu
Thomas Ahlering, MD, is Professor and Chief of the Division of
Urologic Oncology at the University of California, Irvine. Now in its
fifth year of robot-assisted surgery, the UC, Irvine robotic-assisted
laparoscopic prostatectomy experience is one of the oldest programs in
the world. Dr Ahlering initiated the program and has performed
minimally invasive robotic prostatectomies on more than 350 patients
and is a recipient of Intuitive Surgical's Pioneer of da Vinci Urology Surgery (2005).
Douglas Skarecky, BS, is a Staff Research Assistant in the Department of Urology at the University of California, Irvine, and has published more than a dozen articles on robotic prostatectomy with Dr. Ahlering.
References
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2. Guillonneau B, Vallancien G. Laparoscopic radical prostatectomy: initial experience and preliminary assessment after 65 operations. Prostate. 1999;39:71-75.
3. Abbou CC, Salomon L, Hoznek A, et al. Laparoscopic radical prostatectomy: preliminary results. Urol. 2000;55:630-634.
4. Menon M, Shrivastava A, Tewari A, et al. Laparoscopic and robot assisted radical prostatectomy: establishment of a structured program and preliminary analysis of outcomes. J Urol. 2002;168:945-949.
5. Ahlering TE, Skarecky DW, Lee DI, Clayman RC. Successful transfer of open surgical skills to a laparoscopic environment using a robotic interface: initial experience with the laparoscopic radical prostatectomy. J Urol. 2003;170: 1738-1741.
6. Wiklund NP. Technology insight: Surgical robots-expensive toys or the future of urologic surgery? Nature Clinical Practice-Urology. 2004;1:97-102.
7. Tewari A, Srivasatava A, Menon M, Members of the VIP Team. A prospective comparison of radical retropubic and robot-assisted prostatectomy: experience in one institution. BJU Int. 2003;92:205-210.
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9. Basillotte J, Ahlering TE, Skarecky DW, et al. Laparoscopic radical prostatectomy: review and assessment of an emerging technique. Surg Endosc. 2004;18:1694-1711.
10. Ahlering TE, Eichel L, Edwards R, et al. Robotic radical prostatectomy: a technique to reduce pT2 margins. Urology. 2004;64:1224-1228.
11. vanVelthoven R, Ahlering TE, Peltier A, et al. Technique for laparoscopic running urethrovesical anastomosis: “The Single Knot Technique.” Urology. 2003;61:699-702.
12. El-Hakim A, Tewari A. Robotic prostatectomy- A Review. Medscape General Medicine. 2004;6(4):20.
13. Ong AM, Su LM, Varkarakis I, et al. Nerve sparing radical prostatectomy: Effects of hemostatic energy sources on the recovery of cavernous nerve function in a canine model. J Urol. 2004;172:1318-1322.
14. Gill IS, Ukimura O, Rubinstein M, et al. Lateral pedicle control during laparoscopic radical prostatectomy: Refined technique. Urology. 2005;65:23-27.
15. Eichel L, Chou D, Skarecky DW, Ahlering TE. Feasibility study for laparoscopic radical prostatectomy cautery free neurovascular bundle preservation. Urology. 2005;65:944-948.
16. Ahlering TE, Eichel L, Skarecky D. Rapid communication: Early potency with cautery free neurovascular bundle preservation with robotic laparoscopic radical prostatectomy. J Endourol. 2005;19(6):715-718.
17. Menon M, Kaul S, Bhandari A, et al. Potency following robotic radical prostatectomy: a questionnaire based analysis of outcomes after conventional nerve sparing and prostatic fascia sparing technique. J Urol. 2005;174:2291-2296.
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