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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_699_Библиотеки_им_академика_М_И_Перельмана.pdf
198 Appearance of the mesentery during opencolorectal surgery
Inferior mesenteric vein adipovascular pedicle
(a)
(b)
mesocolon
Left
mesocolon
Duodenum
Inferior mesenteric
vein
Mesenterotomy
through avascular
region of left
Figure 14.22 Inferior mesenteric vein adipovascular pedicle. (a) Intraoperative view of the inferior mesenteric vascular
pedicle as viewed from above during an open low anterior resection. (b) Intraoperative view of the inferior mesenteric vein
after skeletonization using diathermy.
SUMMARY
surgery, was developed. e images contained are a reference
atlas and aid in conducting mesenteric based surgery in the
An atlas of the appearance of t he mesentery, associated perito-
open context.
neum, and fascia as observed during open mesenteric-based
15
Instruments used during mesenteric-based colorectal surgery
J. CALVIN COFFEY AND JOHN P. BURKE
Aims 199
Introduction 199
Instruments used to obtain unimpeded mesenteric access 199
Open surgery: Unimpeded mesenteric access 199
Laparoscopic/robotic surgery: Unimpeded mesenteric
access 201
Regaining pneumoperitoneum following
atransabdominal incision during
laparoscopic/roboticsurgery 202
Hemostasis 202
Sources of bleeding 202
The best place to nd helping hands is at the
end of your own arms
Confuscius
AIMS
e aims of this chapter are to summarize the main activities required during mesenteric-based surgery and to
describe instruments currently available to permit these.
e following descriptions are not meant to indicate the
authors’ personal preference.
INTRODUCTION
Devices to enable hemostatic dissection during
mesenteric-based surgery 205
Suction/irrigation 205
Bovie or diathermy 205
Hemostatic sealant devices 205
Newer modalities in obtaining hemostasis 207
Vapor evacuation during laparoscopic and
roboticsurgery 207
Future directions 208
Summary 208
References 208
component structures [1–13]. is is dealt with in detail
elsewhere but will be touched on briey here. e surgeon
must have sucient access as to permit (1) identication of
the mesentery/mesocolon, (2) separation of the components
of the mesofascial interface, and (3) uncompromised access
to adipovascular pedicles (Figure 15.1). Without these
mesenteric-based colorectal surgery becomes a frustrating
and potentially hazardous undertaking and oentimes is
not possible.
e techniques and instruments used dier greatly
between open, laparoscopic, and robotic contexts. e
introduction of robotic platforms will introduce additional
factors [14].
e following is not meant as a comparison of ecacy of
outcomes associated with instrumentation, but rather a
description of how currently available instruments enable
one achieve the goals of mesenteric-based surgery. ese
include (1) the development of unimpeded mesenteric
access and (2) hemostatic dissection.
INSTRUMENTS USED TO OBTAIN
UNIMPEDED MESENTERIC ACCESS
Mesenteric-based surgery requires adequate access to
permit identication of planes and development of their
Open surgery: Unimpeded mesenteric
access
For open colorectal surgery, it is crucial to ensure that the
edges of the abdominal wall are well retracted and that
the primary surgeon has an unimpeded view and access
to the mesentery. As this is an imperative for any abdominal surgery, reliable self-retaining retractors such as the
Gosset, Balfour, or rib spreader should be available from
the outset (Figure 15.2). Other excellent retraction mech-
anisms include the Omni-Tract (Omni-Tract Surgical)
and Bookwalter reactor (Cod man). ese are somewhat
199
200 Instruments used during mesenteric-based colorectal surgery
Inferior mesenteric vein
Mesocolic access
(d)(c)
(a)
Self-retaining retractor devices
Duodenojejunal flexure
Figure 15.1 Intraoperative (laparoscopic) demonstration of unimpeded access to the left mesocolon.
Left mesocolon
(b)
Figure 15.2 (a) Omni-Tract, (b) Bookwalter, (c) Gosset, and (d) Alexis self-retaining devices used in open colorectal
surgery.
expensive and time-consuming in setup, but they signicantly increase the range of retraction possible.
More recently, wound edge retractors have been
developed, which, when folded back on themselves, provide an automatic retraction mechanism for small- to
medium-sized laparotomy wounds. Examples include
the Alexis™ wound edge protector (Applied Medical, CA,
United States) (Figure15.2). ey are used increasingly
in the laparoscopic and robotic setting in exteriorization
of the intestine and mesentery. Although they provide
excellent retraction of the fully relaxed abdominal wall,
intraperitoneal access is poor. Hence, all gastromesenteric mobilization must be conducted prior to their insertion. Emerging evidence suggests that the Alexis® wound
Instruments used to obtain unimpeded mesenteric access 201
Swording
“No swording
(b)
retractor is associated with reduced wound-related infective complications [15].
Laparoscopic/robotic surgery:
Unimpededmesenteric access
In the laparoscopic setting, it is essential to position the
camera and other ports in a manner that gives immediate
and unimpeded access to all regions of the mesentery. One
is advised not to be prescriptive and to vary port number
and placement as required in order to achieve adequate
mesenteric access.
Most surgeons position the laparoscopic/robotic camera
either immediately above or below the umbilicus. A 30° lens
is optimal but not a requirement (it will certainly make one’s
life easier). Adequate CO2 pneumoperitoneum is required
for mesocolic and mesenteric dissection and can generally
be achieved with intraperitoneal pressures of 15 mmHg.
Trocars should be placed using bladeless instruments
under direct vision. Prior to placement the abdominal wall
should be illuminated to prevent damage to subcutaneous
bloodvessels. is is important as the trickling of blood
down the sha of a port into the operative eld can limit
operative views.
Ports are placed on the side opposite where the surgical
intervention is to occur and at a distance of approximately
6cm (i.e., a hand’s breadth from each other) (Figure 15.3a).
is distribution prevents swording, that is, where instru-
ments impede each other by crossing (Figure 15.3b). It is
important that all ports are stabilized at the outset as dislodgement and replacement slow progress and could lead
to a dangerous loss of pneumoperitoneum. A simple suture
placed in the skin and around the gas insuation port can
prevent the dislodgment of the port during surgery.
(a)
“Swording”
Instruments go
across abdomen
at hand’s breadth
from each other
Correct
”
port and
instrument
placement
Incorrect
port and
instrument
placement
Figure 15.3 (a) Correct distancing of laparoscopic or robotic ports to avoid crossing or swording of instruments.
(b)Incorrect placement leads to instruments crossing and impeding further movement.
202 Instruments used during mesenteric-based colorectal surgery
Peritonotomy margin
Hemostatic peritonotomy of peritoneal reflection
Regaining pneumoperitoneum following
a transabdominal incision during
laparoscopic/robotic surgery
It is important to have a fail-safe mechanism of regaining pneumoperitoneum aer an abdominal incision has
been created. e following is appropriate when the laparotomy is limited in length (i.e., in the region of 5cm).
One approach is to use an Alexis wound edge protector.
e latter is rotated to closure and a penrose drain placed
around the point of closure. A clip is placed at this level
to secure the drain, and the skin edges are approximated
using towel clips. e complex is then pulled up ush with
the anterior abdominal wall, thus creating an airtight seal
for insuation.
HEMOSTASIS
e maintenance of hemostasis is a key requirement in
mesenteric-based surgery.
Peritonotomy margin
Sources of bleeding
In general, bleeding during mesenteric-based surgery arises
from one or more of four sources including the (1) mesentery, (2) intestine, (3) fascia, and (4) adhesions. It is useful
to classify bleeding in this manner as it permits a systematic approach to obtaining hemostasis during and aer a
procedure. If bleeding is anticipated then it can be better
controlled. Systematic examination of the peritoneal cavity,
aer procedure completion, is more reassuring than a haphazard search for residual bleeding points.
Mesenteric bleeding occurs when the mesentery has been
dissected through. In addition to the major mesenteric vessels, minute vessels also occur just beneath the mesenteric
mesothelium, in the underlying connective tissue (Figure 15.4)
[16,17]. Bleeding from these is inevitable, as it is not possible
to avoid peritonotomy in conducting a mesenterectomy.
is bleeding is always quickly self-limiting. Heavy bleeding from the mesentery occurs due to disruption of vessels
such as the inferior mesenteric artery or vein, colic vessels,
or substantive sigmoidal branches. is bleeding will not
stop spontaneously and requires particular measures to
regain hemostasis.
Bleeding can also occur at the intestinal margin of
the mesentery, if the marginal vessel has been divided.
Bleeding here is an encouraging rather than problematic
sign (so long as it is appropriately controlled aer identication). Many deliberately divide this vessel and observe
for pulsatile bleeding. ey rst place an artery clip on
the distal aspect of the marginal vessel and then divide
the vessel proximal to this. If bleeding is brisk then a
further artery clip is placed proximally. e absence of
pulsatile mesenteric bleeding is a discouraging sign and
should prompt dissection back to a level where brisk
bleeding occurs.
Mesosigmoidal fascia
Figure 15.4 Intraoperative (open) view of hemostatic
peritonotomy along the right side of the base of the
mesosigmoid.
At the completion of a procedure, and before closing
the abdomen, it is important to inspect the full length
of the mesenterotomy to ensure adequate hemostasis
[18–22].
Minute vessels also occur within Toldt’s fascia where they
are paired with lymphatic channels [16,17,23]. In separating the fascia from the overlying mesocolon (i.e., mesofascial separation), they come under stretch and can bleed. In
general, this bleeding is self-limiting, but it can obscure the
operative eld and increase diculty in identifying operative planes (Figure 15.5a and b). It is important at the completion of a colorectal procedure to thoroughly examine the
fascia for residual bleeding points. Some suggest, probably
correctly, that ooze from these is worsened by antithrombotic prophylactic agents and contributes to generation of
postoperative collections.
Identication of fascial vessels can guide mesofascial
separation. If minute vessels remain on the undersurface
of the mesocolon, these are by denition intrafascial. e
identication of spiral fascial vessels indicates that residual
fascia remains draped to the undersurface of the mesentery
and should be peeled o to expose the vibrant yellow of the
mesentery/mesocolon (Figure 15.6).
Fascial bleeding also occurs when fascia and retroperitoneum are excavated to identify the ureter for safeguarding. is is commonly conducted by many surgeons who
advocate placing a vessel loop around the ureter to further
under fascia
Mesosigmoid
(b)
Mesofascial separation
(a
Mesosigmoid
Hemostasis 203
Hemostatic
mesofascial
separation
Mesosigmoid
fascia
)
Peritoneal reflection
Nonhemostatic
mesofascial
separation
Mesosigmoid
fascia
Mesosigmoid
Figure 15.5 (a) Intraoperative (open) view of hemostatic separation of the mesosigmoid and mesosigmoidal fascia.
(b)Intraoperative (open) view of nonhemostatic separation of the mesosigmoid and mesosigmoidal fascia. The mesofascial
plane is clearly evident in (a) but not in (b) due to the presence of blood.
protect it. Fascial breach and retroperitoneal excavation
can be obviated if the surgeon is mesofascial in plane during dissection (see Chapter 16). While both are associated
with bleeding, neither is likely to cause hemodynamic compromise. However, this will predispose to postoperative
collection development that can, in turn, become secondarily infected and lead to more signicant bleeding. In the
coagulopathic patient, or the reoperative context, fascial,
and retroperitoneal bleeding can be particularly troublesome and should be avoided as much as possible.
204 Instruments used during mesenteric-based colorectal surgery
(Toldt’s ) fascia
Right mesofascial
Right mesofascial separation
Peritonotomy
margins
Cecum
Right
mesocolon
Legend
Mesentery
Fascia
Colon
Peritoneum
interface/plane
(a)
Right mesocolic
(Toldt’s ) fascia
Retroperitoneum
Right mesocolic (Toldt’s ) fascia
Right mesocolon
(undersurface)
(b)
Right mesocolic
Figure 15.6 (a) 2.5D image derived from a 3D digital sculpture demonstrating the relationship between the right mesocolon and fascia after division of the peritoneal reection. (b) Intraoperative image demonstrating the same relationship. The
undersurface of the right mesocolon, Toldt’s fascia, and the retroperitoneum are evident. The fascia has been separated
from the mesocolon on the right but not the left side of the image.
Devices to enable hemostatic dissection during mesenteric-based surgery 205
Dual purpose suction and irrigation device
ion button
DEVICES TO ENABLE HEMOSTATIC
DISSECTION DURING
MESENTERIC-BASED SURGERY
Suction/irrigation
Mesenteric-based surgery relies on maintaining the operative eld as bloodless as possible. Blood obscures mesofascial
and colofascial plane components and the interface between
these. Bleeding is inevitable, which means the surgeon must
rst have means of clearing blood from theoperative eld to
expose the underlying anatomy.
e presence of even minor amounts of blood can
obscure subtle interfaces and lead to digression from anatomic planes. On this basis, availability of an operational
suction and irrigation are essential from the outset of a
procedure. Irrigation can be achieved with a variety of solutions including sterile water or normal saline. e interface
between fascia and mesocolon, and that between colon and
fascia, is subtle and thus easily missed. To avoid this, many
surgeons irrigate extensively as they proceed. In the open
context, frequent irrigation with normal saline or water
from a bladder syringe clears blood to reveal the underlying anatomy. In the laparoscopic and robotic context, dual
lumen devices (Figure 15.7) can be used for gentle meso-
or colofascial separation, allowing concurrent irrigation
(orsuction) and dissection.
In select circumstances, a tonsil swab (15cm × 15cm ×
8 ply) is introduced intraperitoneally to absorb blood and
simultaneously exert a localized tamponade eect. esize
of the swab means that downward pressure is broadly
distributed and can aid in meso- and colofascial separation. In this manner, the surgeon achieves hemostasis and
simultaneously dissects. A few points should be mentioned
that facilitate its usage during laparoscopic surgery. Lack
of familiarity here can lead to frustration and time loss.
For intraperitoneal insertion, the cap of a 12mm port is
removed and the swab introduced directly down the port.
e swab will absorb blood and swell, which means that
it must be unfolded prior to its removal. Sometimes, it
may trap within a port. Should this occur the port should
be removed, the swab gently pushed out, and the port
reinserted.
Bovie or diathermy
e electrocautery instrument used most frequently in
open colorectal surgery is the monopolar diathermy (or
Bovie) (Figure 15.8). e system comprises an active electrode as well as an inactive or dispersive electrode. is
creates a circuit through which the electrical current
(which converts to heat) can be dispersed to ground. In
mesenteric-based colorectal surgery, monopolar diathermy is used in dividing peritoneal reections (peritonotomy), separating fascia from overlying mesentery, or
in dividing through avascular mesenteric (i.e., interpedicular) regions (Figure 15.8a). Ineach of these, the mesentery is thin. It can also be used with care, in skeletonizing
adipovascular pedicles and exposing contained vessels
(Figure 15.8b).
Monopolar diathermy cannot stop bleeding from sigmoidal, superior rectal, or inferior mesenteric diameter
arteries. Other sealant devices are more useful in this context (see “Hemostatic sealant devices” section). Monopolar
diathermy is exceptionally useful for ne dissection in
clearing mesentery o the serosal surface of the intestinal
tract or in clearing an appendices epiploicae o the intestinal surface. is activity is important in enabling the dierentiation of mucosal, submucosal, and seromuscular layers
of the gastrointestinal tract during anastomosis formation
(seeChapter 16).
An additional use lies in division of congenital adhesions before commencing mesenteric mobilization. Many
use the tip of the monopolar diathermy to divide congenital adhesions and thereaer the peritoneal reection.
is activity exposes the mesofascial interface. ecomponents of this may then be separated using the same
approach.
As can be seen from earlier, the monopolar diathermy
has a wide variety of uses in mesenteric-based surgery.
Perhaps its single greatest advantage lies in the fact that it
permits a hemostatic dissection that has largely substituted
sharp scissors-based dissection. Where the Bovie cannot
achieve hemostatic dissection, newer sealant devices can be
used to excellent eect.
Hemostatic sealant devices
Irrigation button
Figure 15.7 Dual lumen device that enables suction or
irrigation.
Suct
As mentioned earlier, the occurrence of vessels immediately
beneath mesothelial surfaces, coupled with their occurrence within the fascia and mesenteric connective tissue,
means that bleeding is inevitable. In the past, this bleeding was extensive as surgeons relied on sharp dissection
using dissecting scissors. Nowadays, devices are available
that both seal and cut meaning that a hemostatic dissection
can readily be achieved. is has radically reduced volumes
of blood loss during colorectal surgery. When their use is
combined with anatomic dissection, the blood loss can be
imperceptibly low.
206 Instruments used during mesenteric-based colorectal surgery
(b)
Diather
Bovie/diathermy
Diathermy tip
(a)
Peritoneal
reflection
Mesosigmoidal
fascia
Inferior
mesenteric
adipovascular
pedicle
my
Figure 15.8 (a) (See also QR 13/6.) Use of Bovie or monopolar diathermy device to separate the mesentery and associated
fascia. (b) Use of Bovie to skeletonize the inferior mesenteric arterial pedicle.
Hemostasis can be obtained using sealant devices by
focally grasping a bleeding point and activating without
cutting (if the sealant device has dual cutting and coagulation functions). is is useful in skeletonizing tissue around
major vessels and in dividing across avascular mesenteric
regions between adipovascular pedicles.
ese devices should be used cautiously as their active
blades can reach considerable temperatures. e eect
of temperature on tissue is demonstrated as follows.
At<70°C, tissue changes are minimal, even within mesentery. Between 70°C and 150°C, there is minor shrinkage and blanching caused by denaturation of collagen.
At temperatures >150°C, cells rupture as the cytoplasm
reaches boiling point and rapidly expands. For temperatures between 200°C and 300°C, tissue carbonizes and
begins to vaporize [24,25].
Small intestinal
Mesenteric fat wrapping
to laparoscopic port
Vapor extraction device
mesentery
Vapor evacuation during laparoscopic and robotic surgery 207
Fat wrapping
Ileum
Figure 15.10 Hemostatic pad.
Figure 15.9 Fat wrapping around the serosal surface of
the terminal ileum.
e type of hemostatic device used is determined by
the anatomic nature of the tissue. Normal mesentery can
be divided through easily using most sealant devices.
Many sealant devices can obtain a hemostatic sealant eect in vessels up to 7mm in diameter. ese have
also been used, albeit with extreme care, in challenging
mesenteries [16,17]. In severe Crohn’s disease, the mesentery is greatly thickened and wraps around the intestinal surface (i.e., creeping fat or fat wrapping) (Figure
15.9 and Chapter 7) [26]. is is due to an exaggerated
but as yet unexplained mesenchymal reaction within the
mesentery [27]. A similar mesenchymal phenomenon
sometimes occurs in complicated diverticular and neuroendocrine disease, and in mesenteric desmoid tumors.
In each of these scenarios, the approach to mesenterotomy and mesenterectomy must be appropriately tailored.
Although sealant devices are useful in separating the
mesentery and intestine at their intersection, they should
not be used along the body of the mesentery in Crohn’s
or diverticular disease. A reliable approach to hemostatic
mesenterotomy in Crohn’s disease is detailed in Chapter
16 on general techniques.
Newer modalities in obtaining hemostasis
Emerging mechanisms of hemostasis involve newer hemostatic agents. e formats used include gels, foams, or
hemostatic pads (Figure 15.10). In the laparoscopic and
robotic setting, hemostatic pads can be introduced through
a 12mm port and then placed on the site of bleeding. It is
oen successful in circumstances where more conventional
approaches have not worked. Several newer agents that are
liquid or powder based are emerging for use in open, laparoscopic, and robotic surgery. ese have had success deep in
the pelvis where bleeding can be troublesome, remote, and
dicult to identify.
VAPOR EVACUATION DURING
LAPAROSCOPIC AND ROBOTIC SURGERY
Vapor arises due to the eects of thermal sealants on mesenteric tissue and should always be evacuated as quickly as
possible. is is particularly important where ne dissection of planar components is required, or when the fat of
major adipovascular pedicles is being dissected through.
In the laparoscopic and robotic context, clear views are
essential to dierentiate adipose from vascular tissue and
avoid inadvertently pinching the side of the vessel in question. Increases in vapor obscure views of anatomic planes
and surgeons need oen withdraw the scope until an overview of the regional anatomy is regained. Not surprisingly, this activity disrupts progress, is time-consuming,
and alters the operative view considerably. A number of
strategies have recently been developed to deal with this
issue. Some use smoke evacuators including the “chimney,” which is an inexpensive channel connected to a port
(Figure 15.11). Although these are inexpensive they may
compromise pneumoperitoneum if le fully open on a continuous basis. e Airseal® device (SurgiQuest, Inc., CT,
Exit port
Adapter connects
Figure 15.11 “Chimney” vapor extraction device for laparoscopic surgery.