Operating Procedure
Beginning of the operation
We start with a rectoscopic examination using the operating rectoscope.
We use the short
rectoscope for tumours in the lower third of the rectum and the longer
barrel for those in
a higher position. In the case of normal sphincter tension the lubricated
obturator is
introduced using light pressure. If there is stenosis of the anal channel
gentle dilation can
be pre-programmed digitally. Next the glass window is added, the fibre
optic cable attached
and manual dilation is provided by the balloon so that the operating area
becomes visible.
Next the manipulator, already fitted with its combination silicone seal, is
inserted. Finally
all remaining tubes are connected and the insufflator switched on. The
viewing lens is
connected with the rectoscope and then the instruments are inserted.
Using the Erbe combination instrument means that 2 instruments are
used at the same time.
If not an additional aspirator is introduced via a third port in the middle of
the sealing system.
Before the operation starts the lens must always be set up so that the
lower edge of the
rectoscope is visible on the image. At the beginning of the operation the
lens is inserted a
bit higher to ensure good overall view. Care should nevertheless be taken
that the lens is
only inserted further than the rectoscope in exceptional cases, e.g. during
the operation
when the upper edge of the tumour should be made visible but the
rectoscope should
remain in the initial position.
Before the operation starts the lens must be adjusted optimally above the
operating area.
For this purpose the holding arm is released and the area for positioning
the marking
points is focused on. During this the rectoscope is held in the left hand
and the right hand
holds the combination instrument and mechanically tests accessibility for
marking.
The area of optimal vision and optimal accessibility with the
operating instruments are critical. Figure 7 shows the area
that can be optically depicted in blue. The white region
shows the area that can be reached with the instruments.
Figure 8 shows how much the surgeon will see. The basic
rule do adhere to is that the lower half of the image is optimal
for surgical tasks, while the upper half of the image should
give a good overall picture.
Fig. 1
Fig. 2
Establishing safe distances and the resection technique
In the case of adenoma a safety perimeter of at least 5 mm is required and
with carcinoma a distance of 10 mm should be left.
The planned resection route follows the coagulation points
that are set out before resection begins (Fig. 9). This means
that if a bleeder occurs, even during the procedure, the
resection line is still visible, even if the edges of the tumour
are not well visible due to the blood.
Fig. 3
Most tumours can be found in the extraperitoneal area of the rectum. In
this position we
always use full-thickness resection. If a carcinoma is in a lateral or
posterior position we
often remove perirectal fat as far as the pelvic muscles.
In order to avoid opening the peritoneum we resect adenomas on the
front wall in the
upper
area of the rectum and in the lower sigmoid using mucosectomy or partial
thickness
resection. Partial resection removes surface muscle fibres to guarantee a
somewhat
thicker preparation layer.
If the field of operation needs to be adjusted the inexperienced surgeon
should
Proceed as follows:
The holding arm is opened, the rectoscope moved to the
optimal viewing position
using the left hand and simultaneously mechanical
accessibility to the operating
area is tested with an instrument held in the right hand. This
is the only way to
guarantee optimal visual focus and working area from the
beginning.
The technique of mucosectomy
At the beginning of mucosectomy care must be taken that the first
incision into the
preparation layer is not too deep. It is also important to note that the
mucosa tears
extraordinarily easy, thus the graspers should only ever hold the edge of
the safety
border and not pull. If the mucosa tears in the direction of the tumour the
pathologist will not longer be able to confirm that it is completely
removed.
At the beginning of mucosectomy (see figure 10) the mucosa
is carefully lifted by
the graspers and then cut away using small careful
preparation incisions. The
incision is made as deep as the silvery muscular layer. These
preparation steps
should be made under the best possible optical enlargement,
thus the lens
should be positioned as near to the operating area as
possible. During the rest of
the preparation the tumour with its safety border is folded up
and preparation
continued cutting alternatively from left and right. Strong
bleeders are seldom
during mucosectomy. Nevertheless even the smallest bleeder
should be localised
and coagulated immediately. To achieve this the blood is
aspirated and the bleeder precisely located using scanning
movements, then compressed and coagulated
using the foot pedal.
Fig. 4
In the case of tumours beginning at the linea dentata that are highly likely
to be
adenomas, the mucosectomy technique for preparation should initiated to
avoid the
partial severing of the sphincter muscle. This can be replaced with fullthickness
resection from 10 mm above the crypten region.
Preparation using the Erbe-TEM-Combination instrument offers the
following
advantages:
Less collision with other instruments.
Continuously good vision and little smoke due to aspiration on the
instrument
tip.
Faster reaction times as coagulation and aspiration instruments do not
have to be
inserted separately.
Care should be taken that the safety border around the upper edge of the
polyp is not
made too wide. For this reason the edge of the tumour must always be
visible so that
the upper safety border can be accurately measured.
Complete haemostasis must be carried out at the end of the operation.
Partial resection
This preparation technique is basically similar to that of mucosectomy.
The removal
Of a thin layer of muscle accompanies a slightly more solid basis for the
operative
specimen and, if an early carcinoma is present, a defined safety border.
Partial
resection can be performed in the vicinity of the sphincter and as well as
in higher
positions on the front wall, although the muscle layer of the bowel is
extraordinarily
thin here and extreme caution must be exercised.
Full-thickness resection
There are two arguments in favour of the full-thickness resection. If a
tumour turns
out to be a T1 carcinoma (which can never be completely excluded) fullthickness
resection guarantees complete removal, with respect to depth.
This technique also allows for the removal of larger polyps, without
causing tears
on the edges, so that the pathologist may successfully confirm the
completed
resection.
At the end of the operation the resected preparation complete
with its safety
margin is spread out on a corkboard.
The technique of full-thickness resection
The order of steps for cutting out the polyp. The safety margin is
determined by the
markers. Start at the lower edge in a clockwise manner.
Fig. 5
The needle is retracted in the case of a bleeder. The bleeder is
compressed and then coagulated
Fig. 6
Preparation of the base using the 5 mm ultrasonic scissors.
The tumour-carrying
wall is raised with the graspers and the fat with vessels is cut
through. This leads
to a clear reduction in the occurrence of bleeders and a
quicker operation time.
Fig. 7
Staunching bleeder in the perirectal fat. The blood is
aspirated using a scanning
motion and the vessel is made visible. Then compression and
coagulation are
carried out.
Fig. 8
Fig. 9
a: Histology Mucosectomy.
b: Full-thickness
c: with perirectal fat
Fig. 10
Adenoma removed by full-thickness resection.
Inadvertent opening of the peritoneal cavity
Any resection at the intraperitoneal positioned rectum can lead to an
unintentional
opening of the peritoneal area, if the level of resection is too deep. If such
an
opening occurs, CO2 is lost in the abdominal cavity and vision of the
operating
field is impeded.
The defect should be closed as quickly as possible. The
procedure to be
followed for this is shown in figure 13a, b. Silver clips will be
placed in the rectal
lumen and the preparation can continue under correct gas
dilation.
a
Fig. 11
In difficult situations in which suturing in the peritonium causes spatial
problems for
the continuing preparation, it is possible to carry out a dilated fullthickness resection
in the peritonium, complete the resection and then at the end close the
whole defect
in a single layer. Nowadays we favour this procedure in must cases.
It is possible to carry out the resection of a full-thickness segment in the
middle third
of the rectum with out problems. This is also possible in the lower third of
the rectum
although suturing on the front wall is impeded.
In the case of tumours in a higher position the intraperitoneal front wall
section should
be resected using the mucosectomy technique, in order to avoid a wide
opening of the
peritoneum.
By tipping up the rectoscope to an extreme angle the area at
the front wall of the
middle rectum is well depicted so that suturing is possible.
Suturing technique
Uncomplicated suturing
In general we use 3x0 moncry with a SH needle for suturing. The suture is
prepared
with the thread shortened to 80 mm so that the silver clip can be pressed
on to the
end. 5mm of thread should be left behind the clip. Before inserting the
needle the
seal lid on the needle holder should be adjusted so that the needle
doesn’
thavet
o
be pulled through the seal lid.
The tip of the needle should be pointing slightly backwards so that during
insertion
the finger-like silicone seal is not destroyed.
Position of the needle
Fig. 12
Automatic setting. Special form of the needle holder
Suturing should always be carried out diagonally. In the case of large
defects we
therefore recommend a positioning suture in the middle of the defect so
that the
relation between the upper and lower wall sections is obvious. After this
the first
suture is placed on the right hand edge of the wound towards the middle
(figure 14a).
The stitches proceed from lumen to extraluminal and then back again into
the lumen.
On the right side of the defect the wall closest to the anus (from the
surgeons
perspective) is always sutured first, from intraluminal to extaluminal and
then again
in the upper area back into the lumen. High tension can be neutralised by
replacing
all 2 or 3 sutures (figure 14b) with intermediary clips.
Fig. 1
To close a semi-circular defect approx. 4 threads are normally used.
When the left edge of the wound is reached the back wall is normally
shortened so
that the front wall hangs down like a curtain. To judge the width of
anastomosis the
front wall should be held up slightly by two instruments.
It is important to note that the suturing must also cover the end point of
the wound,
this can be hidden by a fold-formation.
In the case of very large defects several positioning sutures
must be made
(see figures 20a and b).
Fig. 2
Suturing towards the front wall
Fig. 15
The suture is drawn into the visible area with the forceps