A randomized study to evaluate the effect of a perioperative infusion of dopexamine on colonic mucosal ischemia after aortic surgery.
OBJECTIVE
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 evaluate the effect of dopexamine hydrochloride on its incidence.


METHODS
Thirty patients, mean age 65.1 years (range, 46-84), undergoing elective infrarenal aortic surgery were entered. Preoperative hemodynamic and respiratory parameters were optimized. Patients were then randomly assigned to receive a perioperative infusion of dopexamine at 2 microg/kg per minute (n = 12) or 0.9% saline placebo (n = 18). All patients underwent colonoscopy and biopsy preoperatively and 1 week postoperatively. Specimens were assessed for evidence of mucosal ischemia, presence of mast cell tryptase, myeloperoxidase activity, and both the inducible and endothelial isoforms of nitric oxide synthase.


RESULTS
There was no significant difference in perioperative fluid and blood requirements or hemodynamic and respiratory parameters between the two groups. However, there was significantly less evidence of mucosal ischemic changes in dopexamine-treated patients (n = 1) compared with placebo (n = 8) (P =.049). Furthermore, when preoperative biopsies were compared with those performed 1 week postoperatively, nine (50%) patients in the placebo group 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 cell tryptase and myeloperoxidase expression were increased in patients with histologic evidence of ischemia (P <.05). Furthermore, inducible nitric oxide synthase staining within the vascular (P =.001) and lamina propria (P <.05) components of the mucosa was also significantly greater.


CONCLUSIONS
A perioperative dopexamine infusion affords significant histologic protection to colonic mucosa after aortic surgery.
Baguneid
M S
MS
Department of Vascular Surgery, Manchester Royal Infirmary and Medical School, University of Manchester, UK.
Welch
M
M
Bukhari
M
M
Fulford
P E
PE
Howe
M
M
Bigley
G
G
Eddleston
J M
JM
McMahon
R F
RF
Walker
M G
MG
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001012:Aorta, Abdominal / Q000601:surgery*; D001706:Biopsy; D003106:Colon / Q000098:blood supply* / Q000201:enzymology / Q000473:pathology; D003113:Colonoscopy; D004298:Dopamine / Q000008:administration & dosage* / Q000031:analogs & derivatives*; D018491:Dopamine Agonists / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D018836:Inflammation Mediators / Q000032:analysis; D007262:Infusions, Intravenous; D007413:Intestinal Mucosa / Q000098:blood supply* / Q000201:enzymology / Q000473:pathology; D007511:Ischemia / Q000209:etiology / Q000473:pathology / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000473:pathology; D019001:Nitric Oxide Synthase / Q000032:analysis; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; D019990:Perioperative Care; D009195:Peroxidase / Q000032:analysis; D011183:Postoperative Complications / Q000517:prevention & control*; D011446:Prospective Studies; D012697:Serine Endopeptidases / Q000032:analysis; D053802:Tryptases; D014665:Vasodilator Agents / Q000008:administration & dosage*
D018491:Dopamine Agonists; D018836:Inflammation Mediators; D014665:Vasodilator Agents; C046318:dopexamine; D009195:Peroxidase; C496319:NOS2 protein, human; C496314:NOS3 protein, human; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; D012697:Serine Endopeptidases; D053802:Tryptases; D004298:Dopamine