Small Bowel Surgery
Anastomosis Using the Gambee Technique
Colostomy and Mucous
With Right Colectomy
Small Bowel Bypass
With Ileoileal Anastomosis
and Mucous Fistula
In those cases where the small bowel is involved with
obstruction and/or fistula formation following total pelvic irradiation
and/or advanced malignant disease is impacted in the true pelvis, a
bypass with mucous fistula rather than a bowel resection is the operation
of choice. After small bowel resection, patients frequently develop
(1) recurrent small bowl obstruction from adherence of the anastomosis
site to the large raw dissected areas within the true pelvis, or (2)
recurrent fistula formation at the site of anastomosis, or (3) breakdown
of the closure of multiple inadvertent enterotomies associated with
have preferred bypass with end-to-end anastomosis and mucous fistula
rather than the side-to-side anastomosis technique. Although the side-to-side
anastomosis is more aesthetically acceptable to the patient, it is
frequently associated with recurrent obstruction and persistent fistula
drainage because it does not isolate the diseased portion of small
bowel. The end-to-end or end-to-side technique of small bowel bypass
requires a mucous fistula with an abdominal stoma that eventually contracts,
produces small amounts of mucus, and has a lower incidence of recurrent
obstruction and fistula drainage.
Physiologic Changes. In this operation,
continuity of the intestine is established, and the patient is able
to regain oral alimentation. With loss of the terminal ileum, however,
fat-soluble vitamins and high-molecular-weight fat absorption can be
disturbed, and postoperative diarrhea is frequently encountered. These
undesirable side effects can be reduced with modification of the patient's
diet. Vitamins can be replaced either systemically, as for vitamin
B12, or by therapeutic oral supplementation, as for vitamins A, D,
E, and K, which will be absorbed by the proximal intestine. The mucous
fistula may drain excessively until the pathologic indication for the
bypass has been relieved. One month postoperatively, mucous drainage
is usually scant, and most patients wear only a small gauze dressing
over the mucous fistula stoma site.
Points of Caution. We
have found that the segment of bowel to be brought out as the mucous
fistula stoma is optional. From a physiologic point of view it would
seem that the peristaltic end of the segment should be used. If additional
dissection is required to bring out the peristaltic end of the segment,
however, the antiperistaltic end can be brought out as the mucous
fistula stoma with equal effect.
Caution should be taken to ensure
the vascular integrity of the terminal ileum. The blood supply to the
terminal 10 cm of ileum is unreliable. This is particularly true if
the patient has received total pelvic irradiation. If there is any
doubt as to the integrity of the blood supply in the terminal ileum,
the ileoileal anastomosis should be abandoned, and an ileoascending
colostomy should be performed.
The abdomen is opened through a lower midline
incision extended around the umbilicus, and the peritoneal cavity
is entered. The afferent and efferent loops of intestine associated
with the diseased segment of bowel are identified. The efferent
loop will generally be grossly distended because most patients
have some degree of obstruction, even in ileovaginal fistula
formation. This afferent loop will be smaller and can generally
be traced back from the ileocecal area without significant dissection.
The purpose of this entire operation can be defeated, however,
if the surgeon insists on total identification of all loops prior
to the bypass procedure.
The dilated efferent proximal
segment of bowel is elevated with rubber-shod clamps at a sufficient
distance form the diseased segment. This is usually at the site
that does not require dissection of the bowel into the true pelvis.
The mesentery of the bowel is opened, and the vessels are clamped
and tied. The bowel is transected in an oblique manner.
The distal segment or afferent
loop is likewise elevated, its mesentery is opened, and the vessels
are transected and tied. The bowel is transected in an oblique
manner. Thus the diseased segment of bowel, impacted deep in
the true pelvis, is isolated.
Some surgeons prefer to exteriorize
both ends of the diseased segment of bowel as a double mucous
fistula. We have not found this necessary, however, and multiple
abdominal wall stomata only add to the aesthetic burden for the
patient. The end of the diseased segment to be left in the lower
abdomen and pelvis is closed with the automatic surgical stapler
or with synthetic absorbable suture in the Gambee technique.
Either the peristaltic or the antiperistaltic end can be closed,
and the opposite end can be exteriorized as the mucous fistula.
The proximal (P) and distal
(D) segments of healthy bowel are now anastomosed by either the
suture technique, as described in small bowel resection with
the Gambee anastomosis, or by the automatic surgical stapler
technique, as described in Colon. Note that the diseased
segment of intestine has been closed with the surgical stapler
and is left densely impacted within the pelvis. Thus, no longer
raw areas of dissection are available to which the new anastomosis
might adhere. In addition, multiple inadvertent enterotomies,
with their intestinal spillage, have been avoided.
The ileoileostomy has been performed with
either the suture technique or the stapler technique. The abdomen
has been closed, and the most convenient end of the diseased
segment of intestine has been exteriorized through the lower
midline incision of the abdominal wall closure. Note that the
opposite end of the diseased segment has been closed off and
left impacted within the pelvis. For demonstration purposes,
the diseased segment represented here shows the pathologic condition
alone. The reader should imagine that this segment is much longer
with many entangled loops of intestine dipping deep into the
pelvis, as shown in Figure 1.