Purpose: Colonic ischemia after aortic surgery is associated with increased
mortality and morbidity rates. This study was conducted as a single-center
side arm to a multicenter, randomized, placebo-controlled study to evaluat
e the effect of dopexamine hydrochloride on its incidence.
Methods: Thirty patients, mean age 65.1 years (range, 46-84), undergoing el
ective infrarenal aortic surgery were entered. Preoperative hemodynamic and
respiratory parameters were optimized. Patients were then randomly assigne
d to receive a perioperative infusion of dopexamine at 2 mug/kg per minute
(n = 12) or 0.9% saline placebo (n = 18). All patients underwent colonoscop
y and biopsy preoperatively and 1 week postoperatively. Specimens were asse
ssed for evidence of mucosal ischemia, presence of mast cell tryptase, myel
operoxidase activity, and both the inducible and endothelial isoforms of ni
tric oxide synthase.
Results: There was no significant difference in perioperative fluid and blo
od requirements or hemodynamic and respiratory parameters between the two g
roups. However, there was significantly less evidence of mucosal ischemic c
hanges in dopexamine-treated patients (n = 1) compared with placebo (n = 8)
(P = .049). Furthermore, when preoperative biopsies were compared with tho
se performed 1 week postoperatively, nine (50%) patients in the placebo gro
up and two (16.7%) in the dopexamine group scored worse. Although there was
no significant difference in inflammatory markers between the two groups,
both mast fell tryptase and myeloperoxidase expression were increased in pa
tients with histologic evidence of ischemia (P < .05). Furthermore, inducib
le nitric oxide synthase staining within the vascular (P = .001) and lamina
propria (P < .05) components of the mucosa was also significantly greater.
Conclusion: A perioperative dopexamine infusion affords significant histolo
gic protection to colonic mucosa after aortic surgery.