Gastrointestinal anastomoses
Certain important generalisations can be made
as follows.
Exposure
Any anastomosis becomes difficult if the
surgical access and exposure are poor. This may be caused by inadequate anaesthesia
and muscle relaxation, poor assistance, a badly placed and/or too short
incision, and less than perfect illumination. Poor access may also result from
inadequate mobilisation of the viscera and this is more likely to occur in
oesophageal, colonic and rectal anastomoses as these parts of the gastrointestinal
tract are anatomically fixed and deeply situated.
Blood supply
The only absolute criterion of an adequate
blood supply prior to anastomosis is free bleeding from the cut edges of the
bowel. The blood supply can be compromised by undue tension on the suture line,
devascularisation of the bowel’ during mobilisation, strangulation of the
tissues by tightly knotted sutures and the excessive use of diathermy.
Suture
technique
Experimental work and clinical trials have
shown that inverted suture lines are superior to everted ones, although this
principle has been challenged by Ravitch. The vast majority of surgeons uses an
open method of intestinal anastomosis. One aspect which remains a controversy is
the use of one or two layers. The latter was devised by Czerny and is probably
still the most popular technique today. It is alleged that a single layer
results in less ischaemia and tissue necrosis, and less narrowing of the lumen.
Studies in both experimental animals and humans have shown no great difference
between the two techniques. Anastomoses involving the extraperitoneal portion
of the rectum and also the oesophagus are better performed using a single-layer,
full-thickness technique, as this preserves the blood supply and full lumen
width better than a two-layer technique. Gastrointestinal anastomoses can be
performed end-to-end, end-to-side or side-to-side and can be either ‘open’
or ‘closed’. Generally the method used in any one operation is standard. In
the UK the majority of surgeons employs the open method, removing the clamps
following the placement of the outer, posterior, serosal layer of sutures. The
techniques used for uniting parts of the gastrointestinal tract are as follows.
The
open, end-to-end, two-layer technique (Fig. 49.1). The divided ends of the bowel
are held in crushing clamps and light occlusion clamps are applied across the
bowel, avoiding the mesentery. The outer posterior layer of sutures is usually
placed in a continuous manner (Fig. 49.la) but interrupted sutures can also be
used. The crushing clamps are then cut away.
The
inner layers of sutures are then inserted commencing at the antimesenteric
border with the knot on the serosal surface. A continuous over-and-over
technique is used, care being taken to include all coats of the bowel
wall and avoiding grasping the mucosa with forceps.
The
mesenteric corner of the anastomosis is securely invaginated using a Connell
suture (Fig. 49.lb) and the anterior aspect closed using a continuous Connell
technique (Fig. 49.lc) or a simple over-and-over technique. The suture is then
tied to its other end. The anastomosis is completed by an anterior row of
serosal sutures either continuous from the posterior layer or interrupted (Fig.
49.ld). The mesentery of the small intestine must be closed in every case and
the anastomosis checked for patency (Fig. 49.1e).
An
alternative to the above procedure is to place the inner all-coats first and
then the outer layer, rotating the anastomosis to complete the posterior aspect.
This is not recommended when the mesentery is very fat laden.
If
there is disparity of the bowel ends, the smaller lumen orifice can be widened
by cutting along its antimesenteric border (Cheatle’smanoeuvre).
The
open, end-to-end, one layer technique (Fig. 49.2). This method is increasingly
favoured for end-to-end anastomoses in areas of the gastrointestinal tract where
the blood supply is poor, where there is no serosal coat or the lumen is small.
In infants, a one-layer technique is the rule. Most surgeons favour the use of a
one-layer open technique for the oesophagus and lower rectum.
After
preliminary corner stitches are inserted to steady and approximate the posterior
wall of the anastomosis (Fig. 49.2a), a series of interrupted deep
‘all-coats’ sutures of absorbable material (Dexon, Vicryl or PDS) is
inserted 5 mm apart. After the corners have been reached, the suturing is
continued along the anterior walls as interrupted Lembert stitches with a wide
margin of muscle coat as shown (Fig. 49.2b): some surgeons use interrupted
Connell sutures, but these are less haemostatic and turn in more tissue than the
technique illustrated. The different single-row suture techniques are
demonstrated in Fig. 49.3a—h.
The
closed, end-to-end, single-layer technique (Fig. 49.4). The single-layer,
inverting, closed anastomosis with interrupted nonabsorbable sutures was first
advised by Halsted. The technique has been modified to incorporate the submucosa
so that only the mucosa is excluded. It is commenced by inserting two angle
stitches which are held untied. Posterior sutures are then placed longitudinally
approximately 5 mm apart. Once
finished, the anterior layer is inserted in a similar fashion. When this layer
is in place the clamps are slipped out, the angle sutures tied and lastly the
anterior ones. Patency must always be checked with finger and thumb (Fig.
49.le).
End-to-end
anastomosis (Fig. 49.5).
This
technique is used particularly in surgery of the oesophagus and stomach, and
when there is significant disparity between two ends of intestine.
One
end of the bowel must be closed and this is usually performed with a two-layer
technique or alternatively by a row of staples. The anastomosis is performed as
for an end-to-end one (Fig. 49.1).
Side-to-side
anastomosis. This is usually performed to bypass an obstruction. Both ends are
closed before the side-to-side anastomosis is carried out.
Stapling
techniques (Figs 49.6 and 49.7).
1.Preliminary closure of the bowel ends can be performed using linear
staples (Fig. 49.6) which can be cut away once the purse-string suture is in
place.
2.
End-to-end anastomosis is performed using circular stapling devices
[Premium CEEA (Autosuture) and ILS (Ethicon)]. Purse-string sutures must be
carefully placed and for this the Furness clamp can be utilised (Fig.
49.6a).
Circular staples are very useful for oesophageal and rectal anastomoses. A
rectal anastomosis is illustrated in Fig. 49.6.
3.
The double-stapling technique. The availability of an adjustable-angle
linear stapler, the Roticulator (Auto-suture), has added a new dimension to
stapling techniques, further facilitating low rectal anastomoses. Together
with the Premium CEEA (Autosuture) a low rectal anastomosis is technically
easier and safer. The anastomosis of colon to rectum is effected using the
Premium CEEA circular stapler through the rectal Roticulator linear staple line
(see also Chapter 60).
4.
Side-to-side anastomoses can be performed using the GIA stapler and this
is useful for small-bowel and ileocolic anastomoses (Fig.
49.7).
Special
sites (Table 49.3)
Oesophageal
anastomoses
When suturing the oesophagus, horizontal mattress sutures can be used as
they have less tendency to cut through the
The
stomach is the simplest method of reconstruction but reflux can be a problem.
The sutures are placed as horizontal or vertical mattress sutures in one layer.
The author uses PDS for all intestinal anastomoses. The thoracic oesophagus is
usually anastomosed to stomach (the Ivor Lewis operation) or jejunum. The
technique is the same although the circular stapling device can also be used.
The abdominal oesophagus is almost always anastomosed to jejunum either as a
Roux-enY or to a loop and the circular stapling device is increasingly used in
this situation.
Gastric
anastomoses
Following partial gastrectomy continuity is
restored either to duodenum (Billroth I partial gastrectomy) or to jejunum [Polya
partial gastrectomy (Fig. 49.8)]. The latter can be antecolic or retrocolic and
should be performed by joining lesser curve to afferent loop, the latter being
kept as short as possible. Because of the excellent blood supply absorbable
sutures can be used and placed in a continuous manner. If the operation has been
for carcinoma, e.g. a radical subtotal gastrectomy, it is advisable to make the
anastomosis antecolic in case of recurrence and to use nonabsorbable sutures or
PDS for the outer layer. Closure of the duodenum or stomach can be performed
using a linear stapling device.
Small-intestinal
anastomoses
Jejunojejunal, jejunoileal, ileoileal,
ileocolic and ileorectal anastomoses are all performed following resections for
different disease processes. Like the stomach, the small intestine has an
excellent blood supply and therefore continuous sutures can be used, although
following right hemicolectomy and total colectomy the ileocolic and ileorectal
anastomoses are best performed with an outer layer of interrupted sutures. It is
always advisable to slant the clamps so that less antimesenteric border is left.
The GIA stapling device can be used for any of these anastomoses
Colocolic and
colorectal anastomoses
Because (a) the vascular supply is less good,
(b) distension from gas occurs and (c) the contents are faecal, large intestinal
anastomoses may not heal well. Prior to resection, tapes are placed round the
bowel and tied to ensure that no exfoliated malignant cells are reimplanted. Two
layers of interrupted sutures may be used although most surgeons use only one
layer. It is the author’s practice to use one layer only for extraperitoneal
anastomoses following anterior resection but for very low rectal anastomoses the
circular stapling device is usually used (Fig. 49.6). No anastomosis should be
performed if the colon has been poorly prepared as a low rectal anastomosis will
be placed in jeopardy. The advent of ‘on-table’ lavage popularised at St
Mary’s Hospital, London (Dudley), is employed by the author, which ensures an
empty colon above the subsequent anastomosis. A self-retaining catheter is
inserted into the caecum usually via the base of the appendix following
appendicectomy, or via the terminal
In
the emergency situation, the catheter can be retained as a tube caecostomy which
acts as a gas vent. The terminal portion of the colon tied round the scavenger
tubing is resected prior to anastomosis. The rectal stump is also lavaged from
above and the effluent collected via a proctoscope in the anus. It is usual
practice in cancer cases to employ a cytocidal fluid (mercuric perchloride,
Noxythiolin and Povidone iodine are all used).
Biliary and
pancreatic anastomoses
Either cholecystojejunostomy or
choledochojejunostomy is used to bypass unresectable carcinoma of the head of
the pancreas. Following cholecystojejunostomy a jejunojejunostomy distal to it
is often performed. If there is danger of duodenal occlusion a gastrojejunostomy
is also performed.
For
benign strictures of the common bile duct, excision and primary anastomosis may
be possible. Otherwise a Rouxen-Y loop is used as for some malignant
strictures. Surgeons splint these anastomoses bringing the stent out well away
from the anastomosis through the Roux loop on to the abdominal wall. This Roux
loop should be sutured to the peritoneum and the place marked for subsequent
radiological identification so as to provide access if necessary. Alternatively
an access loop can be constructed and this sutured to the skin marking the site
with a ring. Pancreatic duct anastomosis to jejunum is performed in a single
layer and for all these anastomoses PDS is advocated. A nonabsorbable suture in
the biliary tree can lead to stone formation.
Urological
Most anastomoses are ureterovesical but
ureteroureteric and ureteroileal (Fig. 49.10) are also performed. Ureterocolic
anastomoses are performed less commonly as an ileal bladder is preferable. The
ureter should always be spatulated to increase
Vascular
Except rarely (e.g. following trauma, when a
severed vessel can be repaired primarily) most anastomoses are made to
autografts or to veins (Fig. 49.11). The suture material used must be
nonabsorbable and continuous, although occasionally with small vessels (e.g.
fistula formation for haemodialysis) interrupted sutures are used. When placed
end to end, the graft or vein should be stretched to increase the orifice size.
Microvascular anastomoses are always done with interrupted sutures. If a
vascular anastomosis is close to a joint, e.g. to the hip joint in the groin,
excessive movements at that joint should be avoided until the anastomosis is
healed (see also Chapter 15). Small
clips/staples have been developed for vascular anastomoses which are proving
very quick and useful especially for small vessels and for fistula formation.
New techniques
Biofragmental anastomosis rings have been
proven to be safe anastomotic devices in elective surgery. These can he used
throughout the intestine but it must be pointed out the cost is substantially
higher than for a hand-sewn anastomosis.
Suture less
laser anastomoses have been performed experimentally using the neodymium:
yttrium-aluminium-garnet (Nd:YAG) laser to create tissue welding. Tissue glue
has also been used experimentally to anastomose small intestines.
Protecting an
anastomosis
All anastomoses should be made without tension
in an area of good blood supply. Colonic anastomoses can be protected from the
faecal stream by a proximal colostomy or ileostomy. If drains are used they
should lie alongside and not on the suture line. Gastrointestinal