Nerve Sparing Robotic Prostatectomy: A Novel and Minimally Invasive Treatment of Prostate Cancer

PCRI Insights November 2004 vol. 7, no. 4
See update in November 2007 Insights

By Ashutosh Tewari, MD, Director Robotic Oncology and Prostate Cancer Outcomes at Weill Cornell Medical School, New York Presbyterian Hospital, and Mani Menon, MD, Director of Vattikuti Institute of Urology, Henry Ford Hospital, Detroit, MI

Supported by: Akshay Bhandari, MD, Sanjeev Kaul, MD, James Peabody, MD, Alok Shrivastava, MD, Ashok Hemal, MD, Melissa Fisher, MD and Kurshid Guru, MD

Introduction
Recent developments in the field of surgical robotics have ushered in a new era of minimally invasive surgery that now challenges conventional open surgery.1 Currently available telemanipulation devices allow the performance of complex surgical tasks with dexterity and minimal fatigue due to their ergonomic design, expanded degree of movements, tremor filtering, and 3-D stereoscopic visualization. These devices provide an unsurpassable view of the operative field and unrestricted ability to execute any surgical task. Robotic surgery has been embraced by urologists who have applied it to complex surgical procedures such as pyeloplasty, radical cystectomy, donor nephrectomy, and radical prostatectomy.2-4

Background
Goals of treatment. The goal of treating prostate cancer includes complete eradication of cancer coupled with minimal morbidity and negligible deterioration of quality of life. In order to meet these goals, we use a da Vinci master-slave robot system and have developed a minimally invasive, robot-assisted radical prostatectomy technique. This is accomplished (1) by standardizing a unique sequence of surgical steps, appropriate visual angles using different lenses, optimal retraction strategies, precise suturing steps, and anatomical sparing of the neurovascular structures and (2) by incorporating time-tested open surgical principles.5,6 This technique (which we call the VIP technique) results in excellent oncological and surgical outcomes; causes minimal bleeding, and can be completed in 90 to 160 minutes. The patient satisfaction has been tremendous. Not only do both patients and families appreciate the cosmetic benefits, but also hospitalization has been significantly reduced. Most patients can revert back to their normal lifestyle in less than two weeks.

Dr. Menon developed the technique in Detroit at the Vattikuti Institute of Urology and it has been popularized at several centers in the USA. The data presented here is based on published data from Henry Ford Hospital.5,7-16

Patient selection. Men with clinically localized prostate cancer who choose surgical treatment are candidates for this procedure. The authors use survival prediction tables for selecting patients for surgical treatment. The data has been published17 by the authors and is available online at: www.prostatecalculator.org/survival.html.

Patients undergo a thorough preoperative evaluation including serum PSA testing, an international prostate symptom score (IPSS), a sexual function inventory, a quality of life score, and an incontinence questionnaire. We also record information about other co-morbidities, such as stroke, cerebral aneurysm, diabetes mellitus, hypertension, COPD (chronic obstructive pulmonary disease) and history of myocardial infarctions.

We specifically question each patient regarding his medical history, with emphasis on abdominal surgery, peritonitis, knee or hip surgery, or peripheral neuropathy. Previous abdominal surgery is not a contraindication. However, a history of stroke or cerebral aneurysm is a relative contraindication for this procedure, since, for 1-3 hours, the patient would be placed in a pronounced Trendelenberg position, in which he is placed head down on a table inclined at about 45° from the floor with the knees uppermost and the legs hanging over the end of the table.

Patients are admitted on the day of surgery and receive deep vein thrombosis (DVT) prophylaxis (Heparin 5000 IU SC on call to the operating room) and an antibiotic in the preoperative holding. Venodyne boots, which gently compress the patient’s legs during surgery to prevent postoperative embolic problems, are placed and the abdomen is shaved from nipple to groin.

Brief Overview of Operative Technique

Da Vinci robotic technology (Figures 1, 2 and 3). The da Vinci system uses a sophisticated master-slave robot that incorporates 3-D visualization, scaling of movement and wristed instrumentation. The system has three multijoint robotic arms with one controlling a binocular endoscope and the other two controlling articulated instruments.

Two lenses, 0° and 30º, are used. Two finger-controlled handles (the “masters”) that are housed in a mobile console are used to control the two robotic arms and, together with a foot pedal control, also control camera movement. Instrument movement can be scaled from 1:1, which allows exact finger movements to be transmitted to the instrument tip, to 1:3 and 1:5, which scale down the movements to allow precise and delicate dissection.

The stereoscopic three-dimensional vision allows magnified (10-15-fold) vision with depth perception. This visual advantage improves tissue delineation and precise dissection of delicate neurovascular tissue.

Surgical Team. The robotic team includes both console-side and patient-side surgeons (Figure 4). The operating surgeon sits at the console, and is not scrubbed. After the patient-side team is scrubbed, they place the ports, present the operative field to the operating surgeon, and use suction to keep the field clean.

Surgical Steps. Armed with the findings of anatomic studies,10 we developed our Veil of Aphrodite technique for nerve-sparing. The details of robotic prostatectomy technique have been described previously elsewhere.7,8,9,15

We first incise the peritoneum over the bladder (Figure 5).

The prostatic veins are secured with a stitch, and the junction between prostate and bladder is dissected precisely. We control the prostatic arteries (pedicles) by clips, by sutures, or occasionally by individually coagulating the vessels with a bipolar forceps. The anatomic location of the nerves are previously described7 (Figure 6).

These nerves are precisely dissected and left in the patient for future erectile function (Figure 7).7-9,11,12,16,18

The lymph nodes are removed as would be done in any open procedure. The opening in the bladder is sutured to the end of the urethra to re- create the continuity. The endo wrist technology and magnified 3-D vision maximizes precision and allows anastomosis (suturing) to be more secure and watertight.

We try to avoid damaging the muscles surrounding the urethra and thus leave the sphincter intact. This enables early return of urinary control.
We also preserve maximum blood supply to the urethra and other surrounding structures by precisely suturing only those vessels that are entering the prostate and are absolutely required for the safe removal of the cancerous gland. We attempt to identify any local spread by use of frozen sections and take counter measures to maximize cancer control.

Retrieval of specimen and completion of surgery. The cancer containing prostate gland is entrapped (intact) in a thick plastic bag to avoid any tumor spillage. We remove the specimen after slightly enlarging the umbilical incision as required, and we use plastic steri-strips for surgical closure of the incisions.

Postoperative care and discharge. The patients are sent to recovery on intravenous fluids, antibiotics and pain meds. They usually are walking on the evening of the operation and go home either on the same day or the next morning. The catheter is removed between 4-7 days after surgery. It is rare to use blood transfusions in this procedure, and the post-operative pain is minimal. Patients have small cosmetic incisions, and they go back to their work in approximately 12-14 days. Many patients, who are from distant places fly back to their homes in 1-2 days.

Contemporary Results7-9, 11,12,16,18

From a patient perspective,19 the following concerns have been reported to have the most influence on prostate cancer therapy: oncological control (margin and PSA recurrence), pain, complications, convenience (catheter duration and hospital stay) and functional outcomes (incontinence and sexual recovery). Herein, we analyze the results of our published series of patients treated with robotic prostatectomy in comparison with open radical retropubic prostatectomy (RRP),13 bearing in mind the aforementioned patients’ key preference points. The following discussion is based on this work.4 Table 1 shows that the baseline patients’ characteristics in both groups were comparable.

Cancer Control. As shown in Table 2, the oncological results are compared in two groups – 100 RRP patients and 200 robotic patients. The surgical specimen was inked and processed for histo-pathological analysis. Margins were considered positive if there was a tumor present at the ink. For the apex, margins were considered positive if the margins of the apical biopsies, which represent the actual margin of the apical dissection, had cancer.

The Gleason scores and pathological stages were comparable between two groups. Twenty-three percent of the RRP patients had a tumor at the inked margin. In the robotic prostatectomy group, we performed intra-operative biopsies to excise additional peri-apical collar of the distal tissue. The residual positive tumor was seen only in 9% of the cases. A total of 85% of the RRP patients and 92% of the robotic prostatectomy patients had an undetectable PSA at a mean follow-up of 556 and 236 days respectively (p<0.05).

Pain. As seen in Table 2, the robotic prostatectomy patients had much less post-operative pain, which was managed predominantly with oral Cox 2 inhibitors such as Celebrex.®

Inconvenience. Mean hospitalization stay and duration of catheterization were significantly shorter for the robotic prostatectomy group (See Table 2). Therefore the inconvenience of staying in the hospital and the length of time until catheter removal were less with robotic prostatectomy procedure.

Risks and Complications. As shown in Table 3, robotic prostatectomy is quite safe and the minor and major complications were one-fourth those experienced by the patients undergoing open radical prostatectomy.

Nerve-Sparing Results. We have developed some modifications in nerve-sparing that utilizes the benefits of robotic technology. In particular, we have improved three-dimensional stereoscopic vision and intuitive multidirectional movement of miniaturized robotic instruments. The foundations of nerve-sparing have been based on Walsh’s initial principles and later data from cadaver dissections.10 These studies elucidated the course of nerves as seen in Figures 6, 8, and 9. We delicately dissect the nerves using (1) micro scissors and (2) delicate control of bleeders. The incidence of patient reported sexual functions is quite encouraging.

We have also made technical modifications for improved continence as well as sexual function. The anatomy of the sphincter complex is clearly visualized, and we attempt to minimize dissection in the vicinity of continence muscles and preserve its nerve and blood supply.

Continence. Based on third party telephone interviews, we used survival analysis to compute the probability of return of continence by two groups of the patients. Robotic prostatectomy patients achieved continence much more quickly than RRP patients; achieving a 50% return of continence required 160 days in RRP arm as opposed to 44 days in robotic prostatectomy patients (p<0.05).11

Sexual Function. The sexual function was also evaluated using third party telephone interviews. The response was compiled as the ability to (1) achieve erections and (2) maintain erections adequate for intercourse. The analysis was limited to (1) patients who classified themselves as having normal preoperative erections and sexual intercourse and (2) the ones who underwent bilateral nerve sparing. The response indicated that robotic prostatectomy patients’ erections returned more than twice as quickly [50% return of erection occurred at mean follow-up of 180 days vs. 440 days for RRP patients (p<0.05)]. The return of intercourse was also quicker in the robotic prostatectomy group in which 50% patients achieved intercourse at a mean follow-up of 340 days. Conversely, the RRP patients have not yet achieved 50% return of intercourse at 700 days (p<0.05). Forty two percent of robotic prostatectomy and 65% of RRP patients were known to be using Sildenafil (Viagra®) at the time of analysis.11

Operative Comparisons. The robotic prostatectomy patients needed an extra 15 minutes for the setup, but the overall operative times were comparable in two groups. On the other hand, the blood loss of the robotic prostatectomy patients was one-tenth that of the RRP patients. Using this technique, a trained robotic team can perform 3-6 cases a day.

Robotic versus Laparoscopic Prostatectomy

In laparoscopy, the surgeon uses long instruments through small openings and maneuvers them with direct hand contact. Robotic systems use even more delicate instruments that possess two additional degrees of movement excursion (for a total of six, as with a human hand). Comfortably seated at the robot console, the surgeon can maneuver the instruments via a computer interface.

Laparoscopic radical prostatectomy is associated with a steep learning curve. Even in the hands of expert surgeons, laparoscopic radical prostatectomy requires extensive learning; approximately 40 cases are needed to master this technique. In contrast, the learning of robotic prostatectomy seems to be more intuitive and less demanding. Wood and Woolf compared 10 robotic prostatectomies with 10 laparoscopic prostatectomies, all performed by the same surgeon, who is an experienced upper urinary tract laparoscopist.20 Despite this surgeon’s large amount of laparoscopic experience, the mean operative time was on average 145 minutes less for robotic than for laparoscopic prostatectomy.

The estimated blood loss was comparable (< 500 cc), and there were two conversions (to RRP) in each group, but no major complications occurred. The authors’ group1 performed 48 laparoscopic radical prostatectomies and 50 robot-assisted prostatectomies within a 12-month period. The preoperative and intraoperative demographical variables were comparable in both groups as were the operative times, changes in hemoglobin concentrations, durations of hospitalization, positive margin rates, and overall complication rates. All measured clinical and pathologic parameters were comparable to the best laparoscopic radical prostatectomy results reported in the literature.1

Conclusions

Robotic prostatectomy is a safe, effective and reproducible technique for removing the prostate. In most patients, it can be performed within one and a half to two hours with minimal blood loss and few complications. The procedure incorporates principles of both laparoscopic and open radical prostatectomy. The patients enjoy benefits of surgical treatment in the setting of less invasion, minimal pain, limited blood loss and early functional and overall recovery.

References

1. Menon M, Shrivastava A, Tewari A, Sarle R, Hemal A, Peabody JO, Vallancien G: Laparoscopic and robot assisted radical prostatectomy: establishment of a structured program and preliminary analysis of outcomes. J Urol. 2002 sep;168(3):945-9.

2. Stoianovici D: Robotic surgery. Worl J Urol, 18: 289, 2000.

3. Cadeddu JA, Stoianovici D, Kavoussi LR: Robotic surgery in urology. Urol Clin North Am, 25: 75, 1998.

4. Hubert J: Robotic pyeloplasty. Curr Urol Rep, 4: 124, 2003.

5. Menon M, Shrivastava A, Sarle R et al: Vattikuti Institute Prostatectomy: a single-team experience of 100 cases. J Endourol, 17: 785, 2003.

6. Leak B, Wei JT, Gabel, M et al: Relevant patient and tumor considerations for early prostate cancer treatment. Semin Urol Oncol, 20: 39, 2002.

7. Tewari A, Menon M, Peabody J et al: An anatomic map to assist identification of the neurovascular bundle during laparoscopic radical prostatectomy. New Delhi: B.I. Churchill Livingstone, pp. 297-304, 2002.

8. Tewari A, Peabody J, Sarle R et al: Technique of da vinci robot-assisted anatomic radical prostatectomy. Urology, 60: 569, 2002.

9. Tewari A, Menon M: Vattikuti institute prostatectomy: surgical technique and current results. Curr Urol Rep, 4(2):119-23, 2003.

10. Tewari A, Menon M, Peabody J et al: An operative and anatomic study to help in nerve sparing during laparoscopic and robotic radical prostatectomy. Eur Urol 43:444-54, 2003.

11. Tewari A, Srivasatava A, Menon M: A prospective comparison of radical retropubic and robot-assisted prostatectomy: experience in one institution. BJU Int, 92: 205, 2003.

12. Tewari A, Peabody JO, Fischer M et al: An operative and anatomic study to help in nerve sparing during laparoscopic and robotic radical prostatectomy. Eur Urol, 43: 444, 2003.

13. Menon M, Tewari A, Baize B et al: A prospective comparison of robot-assisted anatomic prostatectomy and conventional radical retropubic prostatectomy: the Vattikuti Urology Institute experience. Urology 60:864-8, 2002.

14. Menon M, Tewari A, Baize B et al: Prospective comparison of radical retropubic prostatectomy and robot-assisted anatomic prostatectomy: the Vattikuti Urology Institute experience. Urology, 60: 864, 2002.

15. Menon M, Tewari A, Peabody J: Technique of Vattikuti Institute Prostatectomy. J. Urol.: in press, 2002.

16. Menon M, Tewari A, Peabody J: Vattikuti Institute prostatectomy: technique. J Urol, 169: 2289, 2003.

17. Tewari A, Johnson CC, Divine G et al: Long-term survival probability in men with clinically localized prostate cancer: a case-control, propensity modeling study stratified by race, age, treatment and comorbidities. J Urol, 171: 1513, 2004.

18. Menon M, Tewari A: Robotic radical prostatectomy and the Vattikuti Urology Institute technique: an interim analysis of results and technical points. Urology, 61: 15, 2003.

19. Diefenbach MA, Dorsey J, Uzzo RG et al: Decision-making strategies for patients with localized prostate cancer. Semin Urol Oncol, 20: 55, 2002.

20. Wood DP, Wolf JS: Oncology rather than laparoscopy surgical experience is more important in learning to perform a robotassisted laparoscopic radical prostatectomy. J Urol. 2004; 171(4 Suppl, Abstract 813): 215.

 

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