Early anastomotic repair in the rat intestine is affected by transient preoperative mesenteric ischemia.
BACKGROUND
During bowel surgery, perioperative blood loss and hypotension can lead to transient intestinal ischemia. Recent preclinical studies reveal that the strength of intestinal anastomoses can be compromised after reperfusion. So far, this phenomenon has not been investigated in the very first days of healing when wound strength is lowest.


METHODS
Ischemia was induced in rats by clamping both the superior mesenteric artery and ileal branches for 30 min. Immediately after declamping, anastomoses were constructed in both terminal ileum and descending colon. The same was done in control groups after sham-ischemia. Anastomotic bursting pressure and breaking strength were measured immediately after operation (day 0) and after 1, 2, or 3 days. Anastomotic hydroxyproline content, gelatinase activity, and histology were analyzed.


CONCLUSIONS
In ileal anastomoses, at day 1, both the breaking strength and bursting pressure were significantly (p < 0.05) lower in the ischemic group, while at day 2, this was the case for the bursting pressure only. In the colon, the bursting pressure in the ischemic group was lower at day 1. Anastomotic hydroxyproline content remained unchanged. Increased presence of the various gelatinase activities was found in ileum only at day 0 and in colon at days 1 and 2. Histological mucosal damage was found in ischemia-reperfusion groups.


CONCLUSIONS
Transient mesenteric ischemia can negatively affect anastomotic strength during the very first days of healing, even if the tissue used for anastomotic construction looks vital.
Posma
L A E
LA
Department of Surgery, Radboud University Nijmegen Medical Center, PO Box 9101, 6500 HB Nijmegen, The Netherlands.
Bleichrodt
R P
RP
Lomme
R M L M
RM
de Man
B M
BM
van Goor
H
H
Hendriks
T
T
D000704:Analysis of Variance; D000714:Anastomosis, Surgical; D000818:Animals; D003106:Colon / Q000098:blood supply / Q000601:surgery*; D018093:Gelatinases / Q000378:metabolism; D006909:Hydroxyproline / Q000378:metabolism; D007082:Ileum / Q000098:blood supply / Q000601:surgery*; D007511:Ischemia / Q000503:physiopathology*; D008297:Male; D008643:Mesentery / Q000098:blood supply*; D051381:Rats; D017208:Rats, Wistar; D013314:Stress, Mechanical; D014945:Wound Healing / Q000502:physiology*
D018093:Gelatinases; D006909:Hydroxyproline