Comparison of blood flow and myoelectric measurements in two chronic models of mesenteric ligation.
OBJECTIVE
To determine whether the predictive accuracy of intestinal motility and blood flow measurements is altered by the magnitude of ischemic damage.


METHODS
Inception cohort study (dogs). Motility was measured using a probe that quantifies both the electromyographic (EMG) measurements and the magnitude of evoked contractile response (ECR). Intestinal blood flow was assessed using Doppler ultrasonography in the marginal artery and perfusion fluorometry, which quantifies fluorescein in the bowel wall in dye fluorescence units.


METHODS
Vivarium animal research facilities at a medical school.


METHODS
The blood supply of a 40-cm length of ileum was ligated in 102 dogs: 52 in which the marginal artery was ligated at two points 8 cm apart (severe model), and 50 in which the marginal artery was ligated only once (moderate model). Twenty-four hours after ligation, the motility and blood flow parameters were measured in normal bowel and at 2-cm intervals within the 40-cm ischemic segment. Resection and anastomosis of ischemic bowel was then performed using either EMG, ECR, or fluorometry to determine the site of resection.


METHODS
Anastomotic leak from progressive ischemia.


RESULTS
There were 26 fatal anastomotic leaks, all due to necrosis at the anastomosis. Perfusion fluorometry and ECR measurements did not correlate with survival in either model. An audible Doppler pulse in the marginal artery correlated with survival in the moderate (P < or = .02) but not the severe model (P = .59). The EMG measurements were significantly greater in survivors vs nonsurvivors in both models.


CONCLUSIONS
The EMG measurements may be useful in bowel viability assessment. Correlation of Doppler ultrasonographic findings with survival in the moderate model suggests that blood flow measurements may be more reliable in predicting viability in less ischemic bowel.
Brolin
R E
RE
Department of Surgery, UMDNJ, Robert Wood Johnson Medical School, New Brunswick.
Orland
P J
PJ
Bibbo
C
C
Reddell
M T
MT
Fedorciw
B
B
Gazi
G
G
Semmlow
J L
JL
D000714:Anastomosis, Surgical; D000818:Animals; D002908:Chronic Disease; D004195:Disease Models, Animal; D004285:Dogs; D004576:Electromyography; D005071:Evoked Potentials / Q000502:physiology; D019793:Fluorescein; D005452:Fluoresceins; D005470:Fluorometry; D005544:Forecasting; D005769:Gastrointestinal Motility / Q000502:physiology*; D007082:Ileum / Q000098:blood supply* / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery; D007511:Ischemia / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery; D008026:Ligation; D008641:Mesenteric Vascular Occlusion / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery; D009119:Muscle Contraction / Q000502:physiology; D009130:Muscle, Smooth / Q000503:physiopathology; D010528:Peristalsis / Q000502:physiology; D012039:Regional Blood Flow / Q000502:physiology; D015203:Reproducibility of Results; D014022:Tissue Survival; D018608:Ultrasonography, Doppler
D005452:Fluoresceins; D019793:Fluorescein