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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_938_Библиотеки_им_академика_М_И_Перельмана
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Monitor #1
, light source console
14 Fundamentals ofBasic Laparoscopic Setup
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Fig. 14.1 Basic
operating room lay out
Surgeon’s
Assistant
Scrub Assistant
Video monitors should be positioned across
from the operating surgeon and ideally, multiple
screens can be strategically positioned so that all
participants, including the anesthesia team, surgical assistants, and circulating nurse, may view and
be aware of how the surgery is progressing. Room
lighting should be actively adjusted based on the
stage of the procedure. Initially, overhead and surgical lights should be on, as would occur in any
typical open surgical approach. Once intra-abdominal access is established, overhead lights should
be dimmed and surgical lights shut off. The darkened room will contrast against a brightly lit screen
and will allow for best and safest visualization of
the operative eld. At the conclusion of surgery,
room lights and surgical lights are turned on again
to facilitate closure of the abdominal wall layers.
14.2.3 Patient Positioning
Patient positioning often depends on the operative eld needed. Most laparoscopic surgeries
require the patient to be in the supine position.
Some procedures may require temporary maneu-
Anesthesia
Instrument Tray
Energy Source
console
Gas
Monitor #2
Surgeon
vering of the bed in the Trendelenburg or reverse
Trendelenburg positioning. This allows gravity to
assist in mobilizing intra-abdominal contents to
facilitate visualization. If working on the esophagus or left liver, patient positioning may need to
be in lithotomy position, with legs in stir-ups and
the surgeon positioned in-between the legs. For a
retroperitoneal approach, such as nephrectomy or
retroperitoneal aortic surgery, the best exposure
is achieved by placing the patient in the lateral
decubitus position and then exing the table at
the waist to spread the lateral plane as well as the
intercostal space for thoracoscopic access.
14.2.4 Surgeon Positioning
The surgeon is positioned opposite the surgical
eld and across from the video monitor. He or
she should have an uncompromised vantage point
to safely accomplish the goals of the operation.
Often, assistants will be asked to hold the camera
or retract tissue. With limited space, a great deal
of exibility and dexterity is necessary to do this
effectively.
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Fig. 14.2 Energy source console
M. Rafols et al.
14.2.5 Instruments
There exist a wide variety of instruments used in
laparoscopic surgery, and the list grows daily,
also due to the growth of hybrid procedures
which may require combining laparoscopic techniques with ultrasonography, endoscopy, or uoroscopy. It is important to have a number of these
instruments and modalities readily available,
including instruments for a potentially open
approach. Nowadays, most instruments used in
traditional, open surgery are available for use in
laparoscopic surgery with the necessary size and
length modications that allow for functionality,
despite entry via 5–12mm ports. Unfortunately,
many of these are limited in their degrees of freedom [wrist-like motion] forcing the laparoscopic
surgeon to adjust his or her technique. This limiting factor and subsequent learning curve forced
upon the surgeon is one reason for the delay in
widespread adoption of minimally invasive laparoscopic surgery when it was rst being performed. Fortunately, increases in volume have
proportionally increased new medical devices
such as knot pusher, Bovie hook, Endo Catch
bag, and Endo Stitch™. Figure14.4a–i depicts the
basic essential equipment to perform laparoscopic surgery.
ab
Fig. 14.3 (a) Video monitor console with gas, light, and camera source. (b) Insufator monitor
ab
cd
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14.2.6 Establishing
Pneumoperitoneum
In order for appropriate visualization and maneuvering to take place within the abdomen, creating
a surgical eld with adequate separation of tissues is required. This is primarily done by insufating the workspace cavity with a gaseous
substance. Mechanical lift devices do exist; however, due to their bulk, inferior exposure, and
increased postoperative pain, they may prove to
be more of a nuisance. Several options exist for
establishing pneumoperitoneum such as Air,
N2O, helium, neon, argon, and CO2. The latter
has been the most studied and used. It is important to consider both the gas-specic and
pressure- specic effects of each option, especially since these substances may absorb into the
patient’s circulatory system to different extents
and subsequently induce dangerous physiologic
ef
Fig. 14.4 Assorted basic equipment. (a) Laparoscopes
(top), light source (left), and camera (right). (b)
Insufation tubing. (c) Suction irrigator. (d) 0 (top) and 30
(bottom) degree laparoscope. (e) Scope warmer. (f)
Trocar. (g) Grasping instruments. (h) Scissors. (i)
Maryland
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g
h
i
Fig. 14.4 (continued)
responses. Those with poor absorption such as
the inert gasses have an increased risk for gas
embolus. With CO2 on the other hand, diffusion
into the patient’s tissue can result in hypercarbia
and ensuing acidosis, increased afterload, even
myocardial stress [5]. The physiologic changes
associated with CO2 pneumoperitoneum will be
discussed later in this chapter.
When deciding upon where to initially gain
entry, it is important to consider what may be
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found underneath the skin. The surgeon’s rst
choice is at the umbilicus. The umbilical stalk
naturally converges the tissue planes, and an
approach here will minimize the depth of tissue
layers traversed. Alternatively, in patients with
previous surgical scarring especially at the midline, access via Palmer’s point (3cm below the
left costal margin, midclavicular line) may provide safe entry in avoiding potentially adhered
loops of bowel.
14.2.6.1 Veress Needle
In the virgin abdomen, one method of gaining
entry to the abdomen is with the use of a Veress
needle (Fig.14.5). This spring-loaded needle is
designed to retract its pointed end upon interface
with resistance. Thus, when the surgeon “pops”
through the abdominal wall fascia and then the
peritoneum, it is understood that there now exists
direct access from the environment to the peritoneal space. Anterior retraction or lifting of the
Fig. 14.5 Veress needle
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abdominal wall layers, such as with two penetrating towel clamps, away from the viscera can
facilitate safe entry. The gaseous substance of
choice can ow via the needle’s shaft and insufation of the abdomen begins. With pressure
feedback monitoring on the insufation console,
low (<5 mmHg) starting pressure ensures the
needle’s tip is outside of abdominal wall layers.
Further, the surgeon may instill normal saline and
note the ease with which it enters the abdomen.
Inltrating with normal saline and noting clear
uid return on aspiration conrm the needle tip
rests outside loops of bowel.
Once the abdomen is appropriately inated to
15mmHg, standard trocars, e.g., 5 or 10 mm in
diameter, may be introduced with a now minimized possibility of organ injury. Trocar tips are
generally aimed away from the sacral promontory and the great vessels. Often, the initial trocar
placement is performed under direct laparoscopic
visualization through an optic trocar. Once this is
placed, the remaining trocars are placed under
direct visualization as they are inserted through
the abdominal incisions.
14.2.6.2 Hasson Technique
When a patient has had multiple previous abdominal surgeries, it is advisable to gain entry via a
more direct route in the event adhesions from
previous surgeries have developed and xed
loops of bowel or other organs are against the
peritoneal surface. The initial incision is then
made adjacent to or within the umbilicus.
Dissection is carried down through Camper’s and
Scarpa’s fascia into the paucity of abdominal
wall musculature at midline which allows entry
into the peritoneal cavity. Securing the fascia on
either side of the incision can be achieved with
two clamps or stay sutures allowing for elevation
away from intra-abdominal organs and a safe
incision through the fascia and peritoneum. Now,
a blunted trocar (Fig.14.6) may be advanced into
the abdomen. Replacing the clamps with suture
that can be wrapped around the trocar for added
security is the nal step prior to passing the trocar
tip into the abdominal cavity. If preferred, a clean
nger swipe can add reassurance prior to trocar
entry.
14.2.6.3 Optical Trocar
A hybrid of the aforementioned approaches is
peritoneal cavity access with a direct optical seethrough trocar. Here, the 0° laparoscope is placed
within the transparent 5mm trocar, and the surgeon is able to visualize the abdominal wall layers as the trocar rotates and separates the fascia
and muscle bers. Guided entry is performed following small skin incision made wide enough to
accommodate the trocar. Then, a twisting motion
with controlled entry is performed with visualization of each abdominal wall layer with the end
point here being visualization beyond the peritoneal lining and within the abdominal cavity. This
technique may be combined with Veress pneumoperitoneum prior to entry, though insufation
may also begin after trocar entry.
14.2.7 Troubleshooting Common
Problems
There exist a number of common hiccups that
can easily derail the progress of a surgery. Many
of these will resolve with a quick x; however,
Fig. 14.6 Blunted
trocar for Hasson
technique
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the procedure may be severely hampered without knowledge of such remedies. For instance,
when establishing and maintaining pneumoperitoneum, high-pressure readings could signal
insufation of an incorrect tissue plane, i.e.,
within the abdominal wall and hollow viscus. It
is best to begin insufating the abdomen with a
low-ow setting (e.g., 3L/min). If the monitor
reads an unexpectedly high pressure, insufation
should be immediately stopped, and the trocar
should be repositioned followed by careful
exploration of all underlying organs. Once in the
correct tissue plane, insufation can be expedited with a “high ow” rate (e.g., 40 L/min).
For reference, a typical insufator monitor is
depicted in Fig.14.3b.
Further, when initially viewing via a laparoscope, the temperature difference between the
room and the abdomen will produce fogging of
the lens until these equalize. To prevent this, a
scope warmer (Fig.14.4e) can be employed to
adjust the temperature of the lens and defogging
solution can be applied to the scope’s tip. To
expedite having a clear view once inside the
abdomen, a gentle and brief wiping of the camera against the liver, peritoneum, or omentum is
safe. Other reasons why there may be a subpar
image include if the camera is out of focus or the
light adjustment was not previously white
balanced.
14.2.8 Physiologic Eects
ofPneumoperitoneum
The most common gas used for pneumoperitoneum is carbon dioxide (CO2) because it is relatively cheap and widely available, suppresses
combustion, is rapidly absorbed into the peritoneum, and is easily eliminated from the body.
Nonetheless CO2 pneumoperitoneum has a physiologic effect on the human body. These effects
can be divided into chemical gas-specic or
mechanical pressure-specic effects. During the
procedure monitoring of cardiac rhythm, oxygen
saturation, end-tidal CO2, heart rate, blood pressure, and urine output is critical to safe laparoscopic surgery.
14.2.8.1 Gas-Specic Eects
CO2 is readily absorbed into the circulatory system and carried to the alveoli. The diffusion coefcient of CO2 is 20 times greater than that of
oxygen making it very soluble in the blood. The
lungs eliminate CO2 during expiration by increasing minute ventilation which is the primary
mechanism of eliminating CO2. Also, the bone
can buffer up to 12 L of CO2. Normally these
mechanisms prevent hypercarbia and respiratory
acidosis. However, when the limits of the body’s
buffers are overwhelmed, there will be an
increased arterial P CO2 and an abrupt increase in
end-tidal CO2. This will eventually lead to a
decrease in the serum pH.These changes can be
seen in patients with severe cardiopulmonary disease in the rst 15–20min of pneumoperitoneum,
after which a steady state will be achieved. These
physiologic changes may also be seen during
long cases. In these circumstances, the anesthesiologist may require the patient to come off pneumoperitoneum and hyperventilate the lungs.
Off- loading CO2 may be achieved by an increase
respiratory rate or tidal volume, keeping in mind
that a respiratory rate greater than 20 breaths per
minute may cause worsening of hypercapnia secondary to poor oxygen exchange. If the tidal volume is increased too much, barotrauma or
excessive movement of the surgical eld may
result. Severe respiratory acidosis is uncommon
if patient has normal pulmonary function, but it
could lead to tachycardia as well as an increase in
systemic vascular resistance and blood pressure,
thus leading higher myocardial oxygen demand
and risk for cardiac ischemia. Changes in cerebrovascular autoregulation can also be seen with
high serum CO
levels [3, 4].
2
14.2.8.2 Pressure-Specic Eects
Pneumoperitoneum can also increase intraabdominal (IA) pressures and can affect the cardiovascular, pulmonary, and renal organ systems
[5]. Increased IA can decrease renal blood ow,
glomerular ltration rate, and urine output.
Frequently there is an observed intraoperative
oliguria secondary to decreased renal venous
ow [6]. This is immediately reversible when
pneumoperitoneum is completed at the end of the
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case. Pneumoperitoneum can also indirectly
increase renin and antidiuretic hormone levels
leading to sodium retention and free water absorption. On the other hand, this effect can take up to
1h to reverse.
Elevated IA pressure affects the cardiovascular system in many ways. One of the benets of
laparoscopic surgery is that insensible uid loss
is much less when compared to open abdominal
surgery. Nonetheless, during laparoscopic surgery intravenous uids are required for uid
shifting occurs with lower extremity venous
pooling, third spacing, as well as blood loss. In
hypovolemic patients, excessive IA pressure may
compress the inferior vena cava and reduce blood
return to the heart and thus preload and cardiac
output. This, combined with reverse
Trendelenburg positioning, promotes venous stasis and venous thrombosis. It is important to prevent venous thrombosis on a patient to patient
basis. This includes sequential compression
devices (SCD) and chemical prophylaxis including agents like heparin or low molecular weight
heparin. For quick procedures >60–90 min,
excessive deep vein thrombosis (DVT) prophylaxis is not warranted since the risk of DVT is
signicantly low [4].
Increased IA pressure on a paralyzed diaphragm is transferred to thoracic cavity. This
increases the lling pressure in both the right and
left atrium. This can be avoided by maintaining
the IA pressure <20mmHg [7]. Increased intrathoracic pressure may also increase the peak
inspiratory pressure, making barotrauma more
likely. However, even in patients with chronic
obstructive pulmonary disease, ruptured blebs
resulting in pneumothorax are rare after laparoscopic surgery.
appropriate distance from each other. This creates space and allows for efcient movement
within the abdomen. Trocars placed within 3cm
of each other are not only redundant but facilitate
collision of instruments within the abdomen.
Ideally, there should be at least 10cm between
the surgeon’s right and left hands.
Although the camera can technically be placed
in any of the ports that accommodate its size, one
port should intentionally be designated as the
camera port. A commonly used analogy is that of
the baseball diamond, where rst and third base
are the surgeon’s right and left hands, respectively, second base is the target organ, and this
leaves home plate to be the designated camera
port (Fig.14.7).
Prior to making any incision, the surgeon
must be mindful of several additional factors
which may not result in a perfect diamond,
though would be ultimately be more benecial
for the patient. For example, incisions within
previous scars or hidden within natural creases
and folds make for a better cosmetic outcome for
the patient with the avoidance of a new, visible
scar. Further, prodding the outside surface of the
abdomen while visualizing the indentation made
from within can assist in avoiding placement of
a trocar within potentially dangerous territory,
such as within an area of dense adhesion that
may contain viscera. Figures14.8 and 14.9 demonstrate typical trocar placement for laparoscopic appendectomy and cholecystectomy,
respectively.
14.3 Alternative Approaches
14.3.1 Single-Incision Laparoscopic
Surgery (SILS)
14.2.9 Trocar Positioning
Trocar placement is paramount to a seamless
operation. When not thoughtfully planned ahead
of time, the surgery may be wrought with frustration at the expense of patient safety. Several cardinal guidelines exist that the surgeon should
bear in mind. First, trocars should be placed with
SILS has recently entered into the limelight of
general surgery. The concept of SILS has been
around for some time. As early as the 1970s, Dr.
Raimund Wittmoser, the “father” of modern thoracoscopic surgery of the autonomic nervous system, used a single-intercostal incision through
which he inserted a multifunctional port which
contained all the instruments and optics. Since
5mm
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Fig. 14.7 “Baseball
diamond” analogy for
trocar placement for, as
an example,
laparoscopic
cholecystectomy
199
Fig. 14.8 Typical
trocar placement for
laparoscopic
appendectomy
there have been multiple published articles establishing its resourcefulness as a standard of laparoscopic surgery, many surgeons have attempted
12mm
5mm
various surgical procedures using this technique.
The foundation of SILS is the use of a single trocar site where multiple laparoscopic instruments
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Fig. 14.9 Typical
trocar placement for
laparoscopic
cholecystectomy
M. Rafols et al.
5mm
3-5mm
3-5mm
12mm
are manipulated via a multiport system.
Placement of the trocar at the umbilicus allows
for minimal visible scar and thus theoretically
more aesthetically appealing than traditional laparoscopic surgical scars. However, many surgeons have questioned its practicality for routine
use over traditional laparoscopic surgery. The
ideal patient for SILS is one with lower body
mass index (BMI), early disease, and no previous
abdominal surgery.
SILS appendectomy has been described in
many pediatric cases, but as the patient size and
weight increase, as does the difculty of the procedure and conversion rates. Adult SILS appendectomy was reviewed in a large meta-analysis of
randomized control studies. The result was longer operating time and higher rate of conversion.
There were no differences between the two
groups in visual analogue pain scores, doses of
analgesics, overall complication rates, wound
infection, or cosmesis.
One of the most commonly performed SILS
surgeries is the single-incision laparoscopic
cholecystectomy. Comparable results have been
reported for SILS versus traditional four-port
cholecystectomy. Rivas etal. reported operating
times of 50min always attaining a critical view
using a two-port and three-port SILS technique
under experienced hands [8]. Acute cholecystitis
is a factor associated with a lower success rate
59.9 vs 93.0% and longer operative time of 78 vs
70 min. A BMI >30 was also associated with
longer operative times [9]. A recent meta-analysis pooling ten randomized control studies evaluated SILC vs laparoscopic cholecystectomy and
found that although there were improved postoperative pain and cosmesis scores, there was a signicant increase in major complications (CBD
injury, requirement for reexploration, and large
vessel injury) with a relative risk of 3.0 as well
as an increase in minor complications. Operation
times were signicantly longer in the SILC
group with a mean difference added time of
23min. No difference was noted in requirement
for conversion to open or addition of extra port
sites were noted [10].
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