Accidental Enterotomy can be a serious complication in abdomino-pelvic surgery, particularly if it is not immediately recognized and treated. Risk of visceral injury increases when complex dissection is required for treatment of cancer, resection of endometriosis, and extensive lysis of adhesion. In a retrospective review from 1984 to 2003, investigators assessed intestinal injuries at the time of gynecologic operations. Of the 110 cases reported, about 37% occurred during the opening of the peritoneal cavity, 38% during adhesiolysis and pelvic dissection, 9% during laparoscopy, 9% during vaginal surgery, and 8% during dilation and curettage. Of the bowel injuries, more than 75% were minor. Mortality from unrecognized bowel injury is significant, and as such, appropriate recognition
and management of these injuries is critical.
The wall of the small intestine, from in to out, consists of layers: the
mucosa, muscularis, and serosa. The muscularis layer is composed of an
inner circular muscle and outer longitudinal muscle. The posterior
parietal peritoneum encloses the bowel to form the mesentery and provide
covering for the vasculature, lymphatics, and nerves supplying the
small intestine. The arterial supply for the jejunum and ileum
originates from the superior mesenteric artery. Branches within the
mesentery anastomose to form arcades. The straight arteries from these
arcades supply the mesenteric border of the gut. Familiarity
with bowel anatomy is important in order to accurately diagnose the
extent of injury and determine the optimal repair technique.
Some basic principles are critical when surgeons face a bowel injury:
1.
Recognize the extent of the injury, including the size of the breach,
the depth (full or partial thickness), and the nature of the injury
(thermal or cold).
2. Assess the integrity of the bowel,
including adequacy of blood supply, prior bowel damage from radiation,
and absence of downstream obstruction.
3. Ensure no other occult injuries exist in other segments.
4.
Obtain adequate exposure and mobilization of the bowel beyond the site
of injury, including the adjacent bowel. This involves releasing other
adhesions so that adequate bowel length is available for a tension-free
repair.
Methods of repair
The two main methods of bowel repair are primary closure and resection with re-anastamosis.
The decision to employ each is influenced by multiple factors. Primary
closure is best suited to small lesions (1 cm or less) that are a result
of cold or sharp injury. However, thermal injury sustained via
electrosurgical devices induces delayed tissue damage beyond the visible
edges of the immediate defect, and surgeons should consider a resection
of bowel to at least 1 cm beyond the immediately apparent injury site.
Additionally, resection and re-anastamosis should also be considered if
the damaged segment of bowel has poor blood supply, integrity, or the
repair would result in tension along the suture/staple line or luminal
narrowing.
Simple small bowel closures
Serosal abrasions
need not be repaired; however, small tears of the serosa and muscularis
can be managed with a single layer of interrupted 3-0 absorbable or
permanent silk suture on a tapered needle. The suture line should be
perpendicular to the longitudinal axis of the bowel at 2-mm to 3-mm
intervals in order to prevent narrowing of the lumen. The suture should
pass through serosal and muscular layers in an imbricating (Lembert)
stitch. For smaller defects of less than 6 mm, a single layer closure is
typically adequate.
For full thickness and larger single defects, a double layer
closure is recommended with a full-thickness inner layer (including the
mucosa) in which the mucosa is inverted luminally with 3-0 absorbable
suture in a running or interrupted fashion followed by a seromuscular
outer layer of 3-0 absorbable or silk sutures placed in interrupted
imbricating Lembert stitches. Care should be taken to avoid stricture of
the lumen and tearing of the fragile serosal tissue. Sutures placed in
an interrupted fashion as opposed to continuous or “running” sutures are
preferred because they reapproximate tissues with less tissue necrosis
and less chance for luminal narrowing. Antibiotics need not be
prescribed intraoperatively for a small bowel breach.
Small bowel resection
Some
larger defects, thermal injuries, and segments with multiple
enterotomies may be best repaired with resection and re-anastamosis
technique. A segment of resectable bowel is chosen such that the
afferent and efferent limbs to be re-anastamosed can be reapproximated
in a tension-free fashion. A mesenterotomy is made at the proximal and
distal portions of the involved bowel. A gastrointestinal anastomotic
stapler is then inserted perpendicularly across the bowel. The remaining
wedge of connected mesentery can then be efficiently excised with an
electrothermal bipolar coagulator device ensuring that maximal mesentery
and blood supply are preserved to the remaining limbs of intestine. The
proximal and distal segments are then aligned at the antimesenteric
sides.
To assist with stabilization, a simple silk suture may be placed through
the antimesenteric border of the segments. The corner of each segment
on the antimesenteric side is incised just enough to cut through all
three layers of the bowel wall. Each GIA stapler limb is passed through
the proximal and distal segments. These are then aligned on the
antimesenteric sides and the GIA stapler is closed and deployed. The
final step is closure of the remaining enterotomy. This is grasped with
Allis clamps, and a line of staples – typically either a transverse
anastomosis stapler or another application of the GIA stapler – is
placed around the bowel just beneath the Allis clamps and excess tissue
is sharply trimmed. The mesenteric defect must also be closed prior to
completion of the procedure to avoid internal herniation of the bowel or
omentum. This may be closed with running or interrupted
delayed-absorbable suture.
Large bowel repair
Defects in the serosa and small
lacerations can be managed with a primary closure, similar to the small
intestine. For more extensive injuries that may require resection,
diversion, or complicated repair, consultation with a gynecologic
oncologist or general or colorectal surgeon may be indicated as colotomy
repairs are associated with higher rates of breakdown and fistula. If
fecal contamination is present, copious irrigation should be performed
and placement of a peritoneal drain to reduce the likelihood of abscess
formation should be considered. If appropriate antibiotic prophylaxis
for colonic surgery has not been given prior to skin incision, it should
be administered once the colotomy is identified.
Standard
prophylaxis for hysterectomy (such as a first-generation cephalosporin
like cefazolin) is not adequate for large bowel surgery, and either
metronidazole should be added or a second-generation cephalosporin such
as cefoxitin should be given. For patients with penicillin allergy,
clindamycin or vancomycin with either gentamicin or a fluoroquinolone
should be administered.
Postoperative management
The
potential for postoperative morbidity must be understood for
appropriate management following bowel surgery. Ileus is common and the
clinician should understand how to diagnose and manage it. Additionally,
intra-abdominal abscess, anastomotic leak, fistula formation, and
mechanical obstruction are complications that may require surgical
intervention and must be vigilantly managed.
The routine use of
postoperative nasogastric tube (NGT) does not hasten return of bowel
function or prevent leak from sites of gastrointestinal repair. In fact,
early feeding has been associated with reduced perioperative
complications and earlier return of bowel function has been observed
without the use of NGT. In general, for small and large intestinal injuries, early feeding is considered acceptable.
Prolonged antibiotic prophylaxis, beyond 24 hours, is not recommended.
Gynecologic surgeons should adhere to surgical principles with sharp
dissection for adhesions, gentle tissue handling, adequate exposure, and
light retraction to prevent bowel injury or minimize their extent.
Laparoscopic entry sites should be chosen based on the likelihood of
abdominal adhesions. When the patient’s history predicts a high
likelihood of intraperitoneal adhesions, the left upper quadrant site
should be strongly considered as the entry site. The likelihood of
gastrointestinal injury is not influenced by open versus closed
laparoscopic entry and surgeons should use the technique with which they
have the greatest experience and skill.9 However, in
patients who have had prior laparotomies, there is an increased risk of
periumbilical adhesions, and consideration should be made for a
nonumbilical entry site.10 Methodical sharp dissection and
sparing use of thermal energy should be used with adhesiolysis. When
injury occurs, prompt recognition, preparation, and methodical
management can mitigate the impact.
