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| Dehiscence of an enterotomy of the jejunum in a dog |
You have just completed an
intestinal anastomosis. The bowel looks healthy, there was minimal
contamination, and the remainder of the abdomen looks good. The omentum has
been tucked into place around the bowel and you close the abdominal incision.
Now begins the period of
postoperative anxiety (for you, not the patient). For the next 3 days every
time the dog vomits, spikes a fever, doesn’t eat, or seems painful in the
abdomen, your “worry-meter” will go off the charts. You will ask yourself many questions: did you remove all of the
diseased bowel, are your sutures holding, was there another perforation or
foreign body that you missed, or is the animal just not healing properly? The
source of the anxiety of course is that postoperative intestinal leakage is a
devastating complication. One study found a dehiscence incidence of 16% of
enterotomies and anastomoses in dogs, with a mortality rate of 74%.1
Dogs with foreign bodies and trauma appeared to be at higher risk for
dehiscence in this study. Clinical evidence of peritonitis appeared at about 3
days postoperatively.
Intestinal wound breakdown
can also occur after full thickness biopsy. Eight of 66 dogs died or were euthanized due to dehiscence
of intestinal biopsy sites in a British clinical study.2 No specific
factors predisposing dogs to biopsy dehiscence were identified in the study.
Pathophysiology
Why do intestinal incisions
sometimes breakdown and can we do anything to prevent it? In a study of dogs
having intestinal surgery, high risk for dehiscence was found if a dog had 2 of
the 3 following clinical factors: pre-existing peritonitis, foreign body, or a
serum albumin of less than 2.5g/dl.3 This is valuable information and serves to heighten
the surgeon’s awareness of postoperative septic peritonitis in selected dogs or
cats that fit these criteria. Monitoring of pre- and postoperative serum
albumin levels after gastrointestinal surgery, in addition to routine patient
parameters (temperature, abdominal pain, vomiting, etc.), appears warranted.
In addition to these
well-documented dehiscence factors, clinical experience tells us that dogs with
metastatic intestinal neoplasia are also at higher risk for incisional
breakdown. Dogs with abdominal carcinomatosis seem particularly prone to poor
healing of their incisions.
Prevention
Prevention of peritonitis secondary
to intraoperative contamination is by following good surgical technique:
packing off the intestine with abdominal sponges, keeping tissues moist,
atraumatic technique, use proper suture materials and patterns, and short surgical time. Abdominal lavage is not indicated in dogs that do not have
generalized peritonitis. Local lavage of the affected intestinal segment is
fine but do not allow fluid to enter the peritoneal cavity. Abdominal lavage
fluid has been found to potentiate peritonitis by distributing bacteria and
inhibiting phagocytosis by macophages and neutrophils. Abdominal lavage however is indicated in animals with existing peritonitis.
Prophylactic antibiotics,
i.e. those given prior to and during surgery but not postoperatively, are also recommended for gastrointestinal
surgery in dogs and cats. However, unless the animal already has septic
peritonitis, antibiotics are not continued after surgery because continued
administration has no benefit and may actually be detrimental. Unnecessary
antibiotic administration leads to development of resistant bacterial species
and may mask the early signs of peritonitis making it more difficult to
diagnose.
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| Closed suction drain (Jackson-Pratt) used for abdominal drainage in peritonitis |
Clinical signs of
postoperative septic peritonitis are: abdominal pain, vomiting, anorexia,
fever, neutrophila and left shift on complete blood count, and peritoneal fluid
that contains bacteria. Treatment is re-operation, resection of the involved
intestinal segment (do not try to just re-suture it), abdominal lavage with
copious amounts of sterile saline, and placement of a closed suction drain
(e.g. Jackson Pratt). Postoperative care includes fluids and colloids,
antibiotics, nutritional support, and careful monitoring.
References
1. Allen DA, Smeak DD, Schertel ER. Prevalence of small
intestinal dehiscence and associated clinical factors: a retrospective study of
121 dogs. J Am Anim Hosp Assoc 1992;28:70-76.
2. C J Shales, J Warren, D M Anderson, S J Baines, R A S White. Complications following full-thickness small
intestinal biopsy in 66 dogs: a retrospective study. Journal of Small Animal Practice 08/2005; 46(7):317-21.
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