Laparoscopic
colorectal surgery for cancer:
Is it ready for prime time?
Article by Martin R. Weiser, M.D.
Dr. Weiser is an Assistant Attending Surgeon at
Memorial
Sloan Kettering Cancer Center and specializes in colorectal
cancer.
This article is provided for information purposes
only.
It is not intended to be used for medical advice. Please read disclaimer.
ABSTRACT
Laparoscopy, with small incisions
and quick recovery, has
revolutionized
abdominal surgical. Although mostly applied to patients with
benign
disease, minimally invasive surgery is now being used in patients with
malignant disease as well. This article focuses on the advantages
and disadvantages of laparoscopic surgery for colorectal cancer.
Results from prospective randomized trials will be reviewed regarding
this
new and popular surgical approach.
INTRODUCTION
Minimally invasive surgery has
gained tremendous popularity after
the
success of laparoscopic cholecystectomy. With the promise of
smaller
incisions, less pain, and quicker recovery, minimally invasive
techniques
have been applied to an increasing variety of surgical
procedures.
Laparoscopic appendectomy, splenectomy, and adrenalectomy have been
accomplished,
and attempts at more complex procedures such as colon and rectal
resection
have been explored.
Laparoscopic intestinal resection
is a challenge. It
requires
dissection in multiple parts of the abdomen, isolation and ligation of
major arteries and veins, division of colonic attachments,
identification
and preservation of critical retroperitoneal structures, intestinal
division,
and reconstruction of bowel continuity. Laparoscopic colorectal
surgery
is now being performed routinely for benign processes such as
inflammatory
bowel disease, rectal prolapse, benign polyps, and diverticular
disease.
In the setting of cancer, however, there has been considerably more
caution
in using these newer surgical techniques. Concerns over the
adequacy
of tumor resection, tumor spillage and the possibility of earlier tumor
recurrence have been raised.
This review will discuss our
current experience with laparoscopic
colectomy for malignant disease. Results from prospective
randomized
trials (in which patients are assigned by chance to either a
laparoscopic
or an open colectomy) as well as from well-constructed prospective
non-randomized
trials, will be reviewed. Finally, our limited experience
with
minimally invasive resection for rectal cancer will be discussed.
LAPAROSCOPIC TECHNIQUES AND
DEFINITIONS
Minimally invasive surgery involves
insufflating the abdomen with
carbon
dioxide gas, which pushes the abdominal wall away from the intestine
and
allows the surgeon to work (figure 1).
Figure 1: The abdomen is insufflated with gas. Thin
specially designed instruments and a magnifying video camera is placed
into the abdomen and used for dissection.
Dissection is performed with
specially constructed thin instruments
that are placed into the abdomen through small incisions, referred to
as
ports. A miniature magnifying video camera is inserted into the
abdomen,
and the surgeon and assistants view the procedure on monitors in the
operating
room (Figure 2).
Figure 2: The surgeon and assistants perform
the operation with the aid of video monitors.
A small incision, often less than
one-third the length normally
required
in open colectomy, is utilized to remove the specimen at the end of the
procedure (Figure 3).
Figure 3: (A) In open
surgery for colorectal cancer, a
midline incision is often used.
(B) In laparoscopic colorectal surgery multiple small incision
are used for instruments and camera. The specimen is removed by
enlarging
one of the incisions.
There is considerable variability in
laparoscopic techniques for
colon
resection. Some surgeons perform only a portion of the procedure
laparoscopically, and then make an incision to complete the resection
(laparoscopic
assisted colectomy). Others perform the complete resection
laparoscopically.
Still others perform hand-assisted laparoscopic surgery, in which the
surgeon’s
hand is used along with laparoscopic equipment to perform the
dissection.
When a minimally invasive
procedure cannot be completed via the
laparoscopic
approach, a larger-than-anticipated incision is created to complete the
surgery. This is referred to as a conversion from the
laparoscopic
to an open procedure. The reasons for conversion include:
intraoperative
complication such as bleeding; the discovery of more advanced disease
than
anticipated; the presence of adhesions or scar tissue from previous
surgery;
and an inability to visualize key anatomic structures. In
general,
the benefits of laparoscopic surgery are fewer or, in some instances,
completely
negated in converted cases(1).
FEASIBILITY OF LAPAROSCOPIC COLECTOMY FOR CANCER
A sound oncologic resection is
defined as complete tumor removal,
with
an adequate intestinal surgical margin and removal of the draining
lymph
nodes. Many prospective randomized studies have compared the size
of the resection margin and the number of lymph nodes removed,
following
open or laparoscopic colectomy for cancer. No difference is seen,
indicating that laparoscopic colectomy for cancer is feasible from a
technical
standpoint(2-4).
In the early experience of
laparoscopic colectomy for cancer, a
few
reports described immediate tumor recurrence at the laparoscopic
incision
sites, referred to as port site recurrences. It was hypothesized
such early cancer recurrence happened after laparoscopy due to tumor
shedding
and/or accelerated tumor growth, secondary to the presence of gas in
the
peritoneal cavity. However, multiple reviews have indicated that
this is not the case. In one such study, which included over 2600
cases, the rate of port site recurrence was approximately 1%, which is
similar to that noted in open colorectal surgery {56}. It is not
currently believed that laparoscopic colectomy is associated with early
wound recurrences.
ADVANTAGES OF LAPAROSCOPIC
COLECTOMY FOR CANCER
What are the advantages to this
approach? The benefits of
minimally
invasive colectomy for cancer are similar to those seen for benign
disease,
and are related to less surgical trauma. The small incisions
utilized
in laparoscopic surgery are associated with considerably less pain, as
reflected in the patient’s reduced postoperative need for narcotic
medication.
Related benefits include earlier resolution of postoperative ileus
(bowel
obstruction caused by temporary intestinal paralysis), quicker
resumption
of diet, and shorter hospitalization. Some studies have noted fewer
complications
and overall quicker convalescence following the laparoscopic approach.
Most postoperative pain is
related to the size of the abdominal
incision.
Therefore, it makes sense that the laparoscopic approach, which uses
small
incisions, is associated with less pain and less need for postoperative
narcotics than the conventional open approach. Many prospective
randomized
studies have noted that those patients assigned to the laparoscopic
colectomy
group needed less pain medication for a shorter period of
time{72}{244}{228}.
Patients who undergo a
laparoscopic colectomy can resume an oral
diet earlier than those undergoing an open colectomy(2;5;6). The
ability to tolerate an oral diet following surgery is related to the
return
of normal intestinal (peristaltic) activity. Following surgery,
the
intestines become paralyzed, referred to as postoperative ileus.
This is caused by many factors, including intraoperative intestinal
manipulation,
pain, and narcotic usage. It is thought that all these factors
are
reduced in laparoscopic surgery, and that this accounts for the earlier
resolution of ileus following minimally invasive surgery.
Although minimally invasive
surgery does not allow for direct
manipulation
or visualization of tissues, there has not been an increased rate of
complication
following laparoscopic colectomy for cancer. In fact some
prospective
randomized trials have noted a lower complication rate with the
laparoscopic
approach(6;7). The reasons for this may be related to quicker
return
of pulmonary function(2), less operative blood loss(2;3;6), and
increased
ambulation following minimally invasive surgery. This difference
is most noticeable in the elderly patient, who is more prone to
postoperative
complications. In one cohort study of patients over the age of 75
years, those undergoing laparoscopic colectomy had half the
complication
rate of those undergoing open colectomy(8).
Laparoscopic colectomy is
associated with earlier postoperative
recovery.
Patients are generally discharged from the hospital after they can
tolerate
an oral diet, when their bowel function returns, and when their
postoperative
discomfort can be controlled with oral pain medication. Most
studies
have shown that patients who undergo laparoscopic colectomy are
discharged
from the hospital 1-3 days earlier than patients who undergo open
colectomy
(1;5;6). Long-term convalescence also appears to be quicker
following laparoscopic surgery. One cohort study compared the
time
it took for patients to return to their usual activity following either
laparoscopic or open colectomy. Patients who underwent
laparoscopic
colectomy returned to their usual activity, on average, two weeks after
surgery, whereas patients who underwent open colectomy reported
returning
to their usual activity seven weeks after surgery(9). Another
study
investigated the ability of elderly patients (>75 years) to resume
an independent
lifestyle following colectomy. After open colectomy, close to 25%
of these patients required admission to some type of assisted living
facility,
while only 5% of the laparoscopic patients required admission to an
assisted
living facility(8).
When long-term quality of life is
measured with questionnaires,
little
difference is seen between laparoscopic and open colectomy(1).
One
reason for this is that most quality of life questionnaires were
developed
for patients with advanced cancer, on chemotherapy, and not for
postoperative
patients. These questionnaires do not adequately measure the
improvements
seen after laparoscopic surgery such as reduced narcotic requirement,
shorter
postoperative ileus, and faster recovery(1;10). Newer
questionnaires
are being developed to study the effects of laparoscopy of quality of
life.
DISADVANTAGES OF LAPAROSCOPIC COLECTOMY
The major disadvantage of
laparoscopic colectomy is increased
operative
time. Most studies report a 30 to 75 minute increase in surgical
time using the minimally invasive approach(2;5;6). The surgeon’s
experience is important, and there is a significant learning curve for
laparoscopic colectomy. A recent report notes that operative time
decreases significantly the greater the number of procedures performed
by the operating surgeon(10).
LONG-TERM RECURRENCE AND
SURVIVAL
A recently reported prospective
randomized trial has published their
long-term tumor recurrence and survival data. This study notes
that
patients that underwent laparoscopic colectomy had fewer tumor
recurrences
and were less likely to die from colon cancer compared with patients
that
underwent open colectomy(6). The reasons for this are unclear,
but
the authors speculate that laparoscopic colectomy is may be associated
with less surgical trauma and reduced immune suppression.
This
study is relatively small, with a total of 219 randomized patients, and
before there is wide acceptance of laparoscopy for colon cancer these
results
need to be verified by larger, multicenter trials. One such
trial, sponsored by the National Cancer Institute, has recently
completed
accrual of more than 900 patients and tumor recurrence and survival
data
should be available in the next few years.
RECTAL CANCER
Laparoscopic rectal resection is
considerably more difficult than
colon
resection, due to the narrow confines of the bony pelvis, and the need
to identify retroperitoneal structures such as the nerves that control
sexual and bladder function(11). The few studies concerning
minimally invasive rectal resection for cancer indicate that the
procedure
is safe and feasible; however, more often than not, it cannot be
entirely
performed laparoscopically, and an incision is required to complete
dissection
low in the pelvis(12). This is referred to as the hybrid approach
in which a portion of the procedure is performed laparoscopically
followed
by a small incision to complete the resection and
reconstruction(13).
One prospective study noted that patients who undergo hybrid-type
rectal
resection have an incision half the size, quicker return of bowel
function,
and significantly shorter hospitalization than patients who undergo
open
rectal resection(13). Laparoscopic rectal resection is currently
an active field of research.
CONCLUSION AND FUTURE DIRECTIONS
Minimally invasive colectomy for
cancer is feasible in experienced
hands.
The laparoscopic approach to colon cancer is associated with smaller
incisions,
reduced pain, less postoperative narcotic requirement, shorter
hospitalization,
and quicker recovery. There is no increased complication rate,
and
some studies have noted fewer complications with the laparoscopic
approach.
In most studies, the laparoscopic procedure does take longer than an
open
procedure; and there is a surgeon learning curve. At this time, there
is
no indication that the laparoscopic procedure is associated with worse
long-term outcome, and one report indicates that patients have improved
survival following laparoscopic colectomy for cancer. However
before
laparoscopic colectomy can be advocated routinely for colorectal
cancer,
recurrence and survival data from larger, multicenter randomized
trials,
such as the one sponsored by the National Cancer Institute must be
analyzed.
Minimally invasive surgery for
colorectal cancer is an evolving
field.
Patients undergoing laparoscopic colectomy for cancer should be
monitored
in a research setting, with data collection and
analysis.
Areas of active research include: patient selection to reduce
conversion
rates; the immunologic benefit of minimally invasive surgery; and the
application
of laparoscopy to rectal cancer surgery. With further
research, the appropriateness of minimally invasive surgery for
colorectal
cancer patients will be further defined.
AKNOWLEDGMENTS:
The author would like to acknowledge the significant editorial
assistance
of Jenifer Levin.
Click over the logo
below
to visit the CancerNews™ site