Advanced Robotic Techniques Prostatectomy
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prostate cancer surgery

What is ART™?

ART™ (Advanced Robotic Technique) prostatectomy is a term that encompasses the robotic surgical techniques developed by Dr. Ash Tewari and his team in the course of over 3500 robotic prostatectomy procedures performed over the past eight years. Dr. Tewari continues to perform prostate cancer surgery, around 50 per month; less than a handful of surgeons worldwide have his experience with this procedure.
The ART™ technique refines the robotic approach to attain the best prostate cancer treatment results. The benefits include:

  • High rates of early post surgical continence.
  • High rates of sexual function recovery
  • Minimization of blood loss during surgery
  • Avoidance of thermal cauterization to control bleeding during nerve sparing surgery and thus better preserve nerve health
  • Minimized post-surgical pain
  • Minimal post-surgical hospitalization

ART™ Surgical Outcomes

Complete cancer removal is generally dependent on whether the cancer is contained within the prostate gland (stage T1 and T2 cancers). T3-stage cancers, which sometimes can be detected with a digital rectal exam and which have extended through the outer covering (capsule) of the prostate, are less likely to be completely removed through surgery. One measure of surgical success is through the microscopic examination of the removed gland. If no cancer is found on the specimen surface (negative margin) the cancer is thought to be eradicated. Another measure is the periodic post surgery measurement of PSA levels; if these levels remain at undetectable to very low levels (ideally, less than .01 ng/ml) the cancer is thought to be completely gone. Based on December 1, 2007 data from Dr. Tewari's most recent patients, the positive margin rate for those with T1 and T2 cancers is less than 5%.

Dr. Tewari on Robotic Surgery and Prostate Cancer

We asked Dr. Tewari to talk about the issues he faces and the robotic surgery techniques he employs in treating prostate cancer.


Q. What is ART™ prostatectomy?

A. ART™ is not just an acronym. It is a carefully thought through approach using robotic prostatectomy to treat prostate cancer patients. An integral part of this approach is to visualize the nerves around the prostate as a hammock of delicate fibers on which the prostate is resting. This is the Tri-zonal neural architecture.

prostate cancer treatment
ART™ Prostatectomy is performed through small dime-sized incisions in the abdomen.
robotic prostatectomy
The Trizonal Neural Anatomy a) Proximal Plate b) Predominant Bundle c) Accessory Pathways and the neural hammock.
prostatectomy surgery
Accessory pathways
robotic prostatectomy
Lateral pelvic fascia left intact
prostate cancer treatment
Lateral pelvic fascia reflected
prostate cancer surgery
The Neurovascular Bundle

The nerves travel within layers of the fascia which is just 1-2mm thick

The Neurovascular Plexus showing the trizonal hammock

The Neurovascular Plexus showing the trizonal hammock

This technique attempts to save every possible nerve fiber; including accessory nerves, which may reside outside the confines of nerve bundles, both around and behind the prostate. The nerves behind the prostate are often ignored and can be damaged. This is a calibrated approach aimed at achieving a fine balance between the competing goals of cancer eradication, urinary control and recovery of sexual function in patients undergoing prostatectomy. ART™ is a technique which has been refined through in-depth studies of periprostatic anatomy, from fresh human specimens, correlated with 3-D magnified video footage of many of my thousands of surgical cases.

The ART™ procedure involves meticulous dissection of the prostate and as a key element, absolutely avoids electrical cautery during the nerve release process, in a completely athermal way. The seeds for the ART technique were planted at the Vattikuti Institute of Urology where I had received my training (1998-2004). Subsequently, I continued anatomic and tissue studies at Cornell and Innsbruck, Austria. My current technique is founded on a summation of thoughts, concepts, anatomic findings, surgical steps and reconstructive efforts, all aimed at eradicating the cancer and at the same time, save nerves around the prostate during robotic prostatectomy. It is important to reflect on the evolution of the nerve sparing procedure which was pioneered by Dr. Patrick Wash from Johns Hopkins. Prior to his work no one knew about these important erectile nerves. The field of robotic surgery actually looks over the shoulders of these giants who initiated, developed and refined nerve sparing techniques which all surgeons use today.

Recently ART™ has incorporated a novel reconstructive approach to minimize and prevent urinary leakage in what we refer to as the Total Anatomic Reconstruction technique (more on total reconstruction later).

Please bear in mind that the above description is just aimed at describing the ART approach. It is not my intention here to present it as a better technique than what is used by other surgeons. To be candid, with all our best intentions, skill and experience our approach does not work for every patient, highlighting the fact that we have lot more progress to make.

Q. Can you please discuss the ART™ nerve sparing technique?

A. There are multiple nerves around the prostate. We do not know the function of every nerve. Some of these nerves may not even have role in sexual function and just be supplying the rectum, bladder and other pelvic structures. We really do not know their function. Our approach is simple; avoid injury to every nerve fiber and other structures as long as we are not compromising the cancer control. To the extent this is accomplished the patients are likely to have the least impact on their bodily functions. This sounds simple but the concept is not easy to execute because of the complexity of the area’s anatomical structures, the minuteness of the nerves, variations in the size and location of important tissues, the tight space in which the prostate is located and the possibility of facing significant bleeding with resulting poor visualization of the operating field. In reality all of the nerves travel within a 1 - 2 mm thick tissue surrounded by fat and blood vessels. Our technique streamlines the process, incorporates strategies for bleeding control and benefits from recent anatomic findings.


The periprostatic levator fascia. Nerve bundles are interlaced within this layer of tissue. Notice the thinness of the tissue.

The prostatic neural architecture. Notice how there are multiple nerve fibers.

The prostate gland is surrounded by a capsule and flimsy layers of fascia containing fat, blood vessels, nerves and the cross communicating ganglions coordinating erection and orgasm. Within the capsule is the cancer, which is slowly eating through the capsule and trying to escape outside, sometimes using nerves as its route of escape. The capsule is thinner than an orange peel and the surrounding fascia is like the outer layers of an onion. Nerves are off white in color with a width of just a couple of hairs. Throw in some fat, blood and inflammation in the mix and you have a quite complicated task of separating nerves from cancer in literally microscopic dimensions.

That is why the success of this operation is judged not just by what is removed, namely the cancer, but also by what is left functioning, such as the nerves for sexual function and sphincter for urinary control.

Therefore we attempt to preserve every nerve fiber and not just neurovascular bundles, which may or may not contain crucial cavernous nerves and which may be a little farther afield from the bundles (tri-zonal picture). Another benefit of our approach is that we work hard at not damaging the relay center made up of ganglions and nerve fibers which coordinates the fine balance between erection, orgasm and bladder function.

Q. How do you execute your technique?

A. Our goal is minimal disruption to the periprostatic tissue in which the nerves are traveling to the prostate from the mid line and working our way around just on the surface of the prostatic capsule. We accomplish this by appreciating the area’s anatomy, meticulously planning each case and approach, using our experience of thousands surgeries and by controlling bleeding from the small blood vessels as they enter the prostate individually, using small clips. We also address the delicate nature of the tiny structures involved, which do not handle heat, traction and manipulation very well, mindful that these structures can simply degenerate if handled roughly.

Q. Surgeons speak about sparing the nerves on one side of the prostate, away from the cancer, but is it possible to save some of the nerves on the side that is involved with the cancer?

A. We studied periprostatic neuroanatomy and noted that these nerves travel in a millimeter thick tissue (lateral prostatic fascia). We found that this narrow space containing nerves could be sub-divided into very tiny inner and outer compartments. Now, mindful of the risk of cancer eroding through the capsule (extra prostatic extension), we are able to separate the nerves in either the inner or outer compartments so that removal of these nerves, if required for cancer control, is not an all-or-nothing deal. This lowers the risk for a positive surgical margin (residual cancer around the nerves) while saving the nerves which could safely be saved.

Q. How about urinary control? We understand that your technique involves the reconstruction of the area's supporting structures to enhance urinary control with excellent outcomes.

A. Urinary control is compromised following any surgical treatment of prostate cancer. Our approach for reducing the rate of incontinence following robotic prostatectomy is rather straightforward. We had identified and studied which of the several supporting structures contribute toward the perfect functioning of urinary control muscles; the sphincter. We also recognized that (at least visually) the entire sphincter area looked quite different than what it was prior to the surgery. Not just for the missing prostate but also because the supporting structures were either removed or were disorganized during removal of the prostate. We address the incontinence issue created by the surgery by reconstituting the support anatomy, carefully putting it all back together. We refer to this approach as the Total Reconstruction Technique and the resultant outcomes are impressive. Ninety-seven percent of these patients are continent after surgery.

Impact of technique
This posterior layer provides support to the sphincter and the entire anastomosis rests on this hammock.

Using this reconstruction the, the sphincter is pulled upwards and provides an extra layer for support to the urinary control muscles.

After total reconstruction, the functional area is restored to prior to surgery.
Postoperative Cystograms

Fig 1: Conventional ART anastomosis

Fig 2: Total anatomic reconstruction technique

The bladder after total reconstruction the bladder does not descend as far as without this technique. This helps in an early return to continence.


Q. Urological surgeons using the conventional, "open" technique often speak about the value of tactile feedback during surgery. How does the ART™ technique compensate for that?

A. There have been concerns about the oncological success rate of the robotic procedure because surgeons trade tactile sensation for the ability to see urological structures under magnification, which may impact intraoperative decision-making regarding the need for excision of nerves. The bottom line concern, is the risk of leaving residual cancer at the postero-lateral surface of the prostate. Margins in the area of nerve release can be observed in patients undergoing open radical prostatectomy and are known risk factors for future biochemical recurrence. Since robotic prostatectomy lacks tactile feedback, trading it off for a relatively clear magnified 3-D visualization, one might argue that the incidence of positive postero-lateral margins should be greater in the robotic procedure. Let’s look at this issue in more detail.

Most concerns revolve around the premise that prostate cancer cells produce changes in the hardness of tissue that can be felt (palpated) by the conventional open surgeon during surgery. The surgeon can then make appropriate adjustments regarding the need for a wider neurovascular resection to achieve negative margins, especially at the postero-lateral quadrant, the location of nerve release. Thus it might seem reasonable to assume a greater incidence of positive surgical margins in this region during robotic radical prostatectomies given the lack of tactile sensation to provide feedback to the surgeon about the nature of the tissue he is working on. However, this logic has never been tested. First, not every induration is an extra prostatic extension (EPE), as change in texture is a non-specific response of tissue to a wide variety of insults and disorders. These include inflammation, infection, multiple biopsies, thrombophlebitis and cancers just to name several. Second, EPE does not necessarily produce induration since early extension is primarily a microscopic phenomenon.

In fact, a counterargument may be made for the advantages of robotic 3-D vision in a tradeoff for touch inasmuch EPE often produces visual clues such as changes in color, texture, bulging and irregularity of surface, stickiness of planes and obvious view of the tumor. All this visual information is available to the robotic surgeon in highly magnified, well lighted, three-dimensional color unobstructed by the typically blood soaked field conventional surgeons operate in.

Q. The relative cancer control efficacy of the touch versus a visual approach, between conventional, open prostatectomy versus robotic, seems all anecdotal. Do you have any data on the subject?

A. The question of whether the lack of tactile sensation translates into a greater incidence of positive margins had not been subjected to formal study so we decided to look at the data for some answers. We hypothesized that in the hands of an experienced robotic prostate cancer surgeon with compensatory visual strategies to overcome the absence of tactile feedback, the incidence of postero-lateral margins in the area of nerve release should not be any different than the statistics published for open surgeries. In order to test this hypothesis, we looked at all of our cases since January 2005 and specifically reviewed the incidence of positive margins at the postero-lateral location. We asked that the data be reviewed by a referee GU pathologist and a sample of data was further verified by a referee pathologist at another institution. We also looked at clinical strategies and technical modifications on trends of postero-lateral margins in our cohort. Presented herein are the results of our analysis involving over 1200 patients. Before we interpret the data, it is important to remember that surgeon experience plays an important role in patient outcomes and there are many very well qualified experts in open prostatectomy who will get an excellent outcomes without the need a for robot. I have personally learned from them various tricks and techniques.

In our analysis, the data indicated that using our approach of careful planning and precise execution of technique, tactile feedback did not confer an advantage over the robotic approach for cancer control at the postero-lateral location. Our results of cancer control were comparable to high volume open prostatectomy centers.

Q. In sum, what do you attribute these results to?

A. I think that a number of factors have amalgamated to produce these results. I believe that experience with thousands of cases gave us very high proficiency in the precise identification of tissue planes, a highly tuned appreciation of periprostatic anatomy and proficiency in risk grouping of patients for various grades of nerve sparing. Additionally, utilizing high resolution 3-Tesla Endo Rectal MRI and liberal utilization of tissue microscopy during surgery, all have contributed towards our oncological optimization approach and have given us comparable margin rates at the postero-lateral aspect of prostate.

Q. How would you compare ART™ results with other prostate cancer treatment modalities?

A. True scientific comparison of outcomes do not exist because the different modalities have not been compared in a prospective randomized manner to date. Therefore, we have attempted to analyze existing clinical treatment data to provide some indicators which may be helpful. The data has been extracted from previously published large center studies and weighs them according to the numbers of patients in each series. It is summarized in a recent publication.

Q. Can you give us a summary of outcome data on robotic/laparoscopic versus open radical prostatectomy?

A. Even rigorously applied data analysis doesn’t always yield universally accepted conclusions. For example, recently there was an article published by Hu et al. in The Journal of Clinical Oncology comparing outcomes of open versus minimally invasive prostatectomy in Medicare patients undergoing prostate cancer treatment. Results revealed that in community hospitals, open prostatectomy fared better than minimally invasive procedure (laparoscopic and robotic combined) in terms of salvage treatment and stricture rates, a study with narrow, specific outcome criteria. Even in the community setting, minimally invasive procedures were safer than the open procedure. There were several concerns and responses to this paper. We analyzed our own data on a Medicare population and our response is attached. Basically we had much lower rates of salvage treatment and strictures highlighting the advantages of surgical experience and technique, which always plays a role in outcomes.

Variable Open Radical Prostatectomy (N=2094, Hu) MIRP (N=608, Hu) Robot-assisted MIRP (N=183, Tewari)
Age 65-69 (%) 51.8 54.2 48.6
70-75(%) 27.6 34.3 31.1
>75(%) 20.5 11.5 9.3
Mean PSA (ng/dl) Not available Not available 6.35
Gleason <=6 Not available Not available 30.29%
7(3+4) Not available Not available 41.14%
7(4+3) Not available Not available 17.14%
8,9,10 Not available Not available 10.86%
Perioperative Complications Overall (%) 36.4 29.8 1.64
Cardiac (%) 6.6 4.3 0
Respiratory (%) 11.7 6.7 0
Vascular (%) 6.5 5.3 0
Wound/Haemorrhage (%) 3.6 1.6 0.54
Genitourinary (%) 8.0 4.4 0
Miscellaneous Medical (%) 46.3 11.0 0
Miscellaneous Surgical (%) 8.0 6.6 1.1
Mean Length of Stay (Days) 4.35 1.42 1.3
Anastomotic Stricture (%) 12 15.2 0.54
Salvage Therapy (%) 9.1 27.8 3.83
Biochemical Recurrence/Failure (%) Not available Not available 4.7
Overall Positive Surgical Margin Rate (%) Not available Not available 6.1
Continence at 6 months Not available Not available 96.1

Departments of Urology, Program in Robotic Surgery, NewYork-Presbyterian Hospital, Weill Cornell Medical College, NY, +Lahey Clinic Medical Center, Burlington, MA, USA, and *Department of Urology, Innsbruck Medical University, Innsbruck, Austria
Accepted for publication 21 September 2007

Q. What is your published data on cancer control, urinary continence and sexual potency following robotic radical prostatectomy?

A. Total reconstruction of the vesico-urethral junction
Ashutosh Tewari, Jay Jhaveri, Sandhya Rao, Rajiv Yadav, Georg Bartsch*, Alexis Te, Edward Ioffe, Miguel Pineda, Senthil Mudaliar, Lang Nguyen, John Libertino+ and Darracott Vaughan

  Group
Variable Control Anterior reconstruction Total reconstruction P
N 214 304 182  
Age, years 64.32 62.84 61.21 <0.05
Body mass index, kg/m2 28.77 28.74 24.98 NS
Prostate volume, mL 54.12 50.73 50.53 <0.05
IIEF 55.91 58.5 54.25 NS
PSA level, ng/mL 6.02 5.94 5.76 NS
Mean follow-up, weeks 108 54 18  
%:
Gleason score
1-6 47.66 28.61 36.26 NS
7 (3+4) 40.65 43.09 50.54  
7 (4+3) 6.07 11.84 7.14  
8,9,10 5.60 6.25 4.94  
Risk Group
Gp 1 32.24 26.60 23.24 NS
Gp 2 31.30 28.32 32.4  
Gp 3 14.01 20.60 23.24  
Gp 4 22.42 24.03 21.08  
Clinical stage
T1a 0.46 0 0 NS
T1c 74.76 77.63 80.76  
T2 23.83 20.39 16.48  
T3 0.9 1.9 2.7  
Pathological stage
T2 87.38 82.89 80.28 NS
T3 11.21 12.17 18.77  
T4 0.93 1.31 0.46  

Margin positive rates (T2)

3.8 7 4.8 NS
NS. not significant

 

  Group
Variable Control Anterior reconstruction Total reconstruction
N 214 304 182
Median time to continence, weeks 12 4 3
& patients with O pads at follow-up (weeks)      
1 13.15 27.00 38.37
4-6 35.21 59.00 82.56
12 50.23 76.67 91.30
24 61.97 85.67 97.14
52 82.16 91.28 N/A
N/A, not available. *At every time point, percentage continence was statically significantly better (P<0.01) after anterior reconstruction vs control (no reconstruction); +At every time point, percentage continence was statistically signficantly better (P<0.01) after total reconstruction vs control (no reconstruction).

Cancer control and the preservation of neurovascular tissue: how to meet competing goals during robotic radical prostatectomy

Ashutosh Tewari, Sandhya Rao, Juan I. Martinez-Salamanca, Robert Leung, Rajan Ramanathan, Anil Mandhani, E. Darracott Vaughan, Mani Menon*, Wolfgang Horninger+, Jiangling Tu+ and Georg Bartsch+

Departments of Urology, Program in Robotic Surgery, NewYork-Presbyterian Hospital, Weill Cornell Medical College, NY, +Lahey Clinic Medical Center, Burlington, MA, USA, and *Department of Urology, Innsbruck Medical University, Innsbruck, Austria
Accepted for publication 27 September 2007
Variable Value Table 1
Baseline The characteristics and outcomes of the patients treated with RP
Median (SD, range), age, years 60 (6, 45-75)  
n (%):
PSA, ng/mL, before RP
<2.5 19 (8.9)  
2.6-4.0 43 (20.2)  
4.1-10.0 135 (63.4)  
10.1-20.0 12 (5.6)  
>20 4 (1.9)  
Biopsy Gleason score
6 154 (72.6)  
3 + 4 36 (17.0)  
4 + 3 12 (5.7)  
>=8 10 (4.7)  
Clinical stage
T1a-b 1 (0.5)  
T1c 159 (74.6)  
T2a 29 (13.6)  
T2b 10 (4.7)  
T2c 12 (5.6)  
T3a 1 (0.5)  
T3c 1 (0.5)  
Median (SD) estimated blood loss, mL 150 (195)  
Intraoperative blood transfusion 0  
After RP
Pathological stage
pT2a 37 (17.3)  
pT2b 7 (3.3)  
pT2c 144 (67.3)  
pT3a 16 (7.5)  
pT3b 8 (3.7)  
pT4 2 (0.9)  
Capsular invasion 36 (17.0)  
Perineural invasion 104 (48.0)  
High-grade PIN 55 (26.0)  
Overall positive margins 14 (6.5) PIN, prostatic intraepithelial neoplasia
Positive margin in organ-confined cancers 9 (4.8)  
Q. How does this translate for the physician seeking to recommend the best treatment for his patient or for the patient trying to make his own treatment choice?

A. The point is this. No randomized trial exists that takes into account every factor and every criteria of even the major treatment modalities, never mind some of the less utilized treatments. The many studies that are done tend to be narrowly focused on one or two outcome criteria and tend to use different patient cohorts. While of interest to the researcher and to the practitioner, they are of lesser direct utility to the end user; the cancer patient.

For the patient, his concerns are broader and more immediately practical. For example, no patient will make a treatment decision based solely whether a given treatment produces lower stricture rates in a cohort of Medicare patients. His concerns are broad; will his cancer be completely removed? Will it come back? How will he recover from the surgery? Will he be incontinent? What will be the degree of his sexual function after surgery?

Even with experience, I personally have patients who never regained sexual function, or are incontinent or had positive margins. A few complications could also occur. This field of surgery is quite humbling and I really think that we have much more to learn in order to help our patients.

The patient will also look for an experienced surgeon, the more experienced the better, because ultimately experienced surgeons tend to have better results and the patient will also look for a well equipped facility with an excellent reputation.

I hope I’ve been able to give you a fair sense of our approach to prostate cancer treatment and to the thinking behind our techniques. While we have some ways to go in our quest toward ideal results, today there are excellent ways of treating prostate cancer and there are many well qualified practitioners.

Good luck with your decision-making and your treatment.

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