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 2500 robotic procedures performed over the past six years. Dr. Tewari continues to perform over 50 prostate cancer surgeries monthly; fewer 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.
ART™ Prostatectomy is performed through small dime-sized
incisions in the abdomen. |
The Trizonal Neural Anatomy a) Proximal Plate b) Predominant
Bundle c) Accessory Pathways and the neural hammock. |
Accessory pathways |
Lateral pelvic fascia left intact |
Lateral pelvic fascia reflected |
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 |
|
|
| 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.
AKT |
