Timing relationships for secondary ischemia in rodents: the effect of arteriovenous obstruction.
The first ischemic insult a tissue suffers is primary (1 degree) ischemia. A second ischemic episode, such as thrombosis after free tissue transfer, may be regarded as secondary (2 degrees) ischemia. Timing relationships were studied in a rodent epigastric-flap model. In a first experiment, the interval between 1 degree ischemia and 2 degrees ischemia was varied. Flaps which had 2 degrees ischemia 12 and 36 hr after the 1 degree episode, had decreased ischemic tolerance, compared with 1 degree ischemic flaps; 2 degrees ischemic flaps, after an interval of 72 hr, had an ischemic tolerance similar to 1 degree ischemic flaps. In a second experiment, the length of the 1 degree ischemia was varied. It was found that as little as 5 min of 1 degree ischemia significantly decreased the subsequent tolerance of 2 degrees ischemia. The possible clinical significance of these results is discussed.
Angel
M F
MF
Department of Plastic Surgery, University of Virginia.
Knight
K R
KR
Biavati
M J
MJ
Mellow
C G
CG
Wanebo
J
J
Amiss
L R
LR
Morgan
R M
RM
D000818:Animals; D006085:Graft Survival; D007511:Ischemia / Q000209:etiology / Q000503:physiopathology*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012867:Skin / Q000098:blood supply; D013524:Surgical Flaps; D013927:Thrombosis / Q000209:etiology; D013997:Time Factors