Gender-specific ischemic tissue tolerance in critically perfused skin

Abstract

Purpose The purpose of this study is to determine genderspecific differences in the development of necrosis in persistent ischemic tissue and to analyze whether differences are due to gender-specific loss of vascular reactivity or change in ischemic tolerance. Methods Hairless mice (skh-1) of both genders were assigned to three groups of adolescent, adult, and senescent age. Critical ischemia was induced by transection of the two distal pedicles of the animal's ear. Microcirculation was assessed over a 5-day period using intravital epifluorescence microscopy. Tissue necrosis, blood flow, functional capillary density (FCD), red blood cell (RBC) velocity, and capillary diameter were analyzed. Results Induction of persistent ischemia caused an agedependent demarcation of nonperfused flap tissue. Adult and senescent females developed markedly more necrosis than age-matched males (49±1% vs. 37±3% and 53±3% vs. 44±2%, respectively; p<0.05), whereas no genderspecific difference in flap necrosis was observed in adolescent animals (31±2% vs. 33±3%). Gender did not affect the amount of microcirculatory dysfunction in the flap. Thus, age-matched females and males exhibited a comparable decrease of FCD, RBC velocity, and capillary dilatory response. Conclusions Both age and female gender may predispose for an increased susceptibility to develop ischemic tissue necrosis. The increased necrosis in female animals does not apply to an aggravated microvascular dysfunction, but rather to a reduced ischemic tissue tolerance.

Bromelain Protects Critically Perfused Musculocutaneous Flap Tissue from Necrosis

“…Though our findings are promising, further research is warranted to test the efficacy of bromelain for the prevention of flap necrosis in different settings because flap survival is influenced by various factors, such as age and gender [ 39 , 40 ]. As capillary and artery numbers can decline in aging tissue, it may, for example, be interesting to assess whether the positive effects of bromelain on flap tissue are reproducible in aged mice [ 41 , 42 ].…”

Early Start of the Dangling Procedure in Lower Extremity Free Flap Reconstruction does not Affect the Clinical Outcome

“…Several studies investigated the tolerance of human skeletal muscle and prefabricated skin flaps to ischemia and reperfusion, the effects of tissue expansion on ischemic tolerance, and the influence of age and gender as well as heat shock preconditioning on free flap tolerance to ischemia. [11][12][13][14][15][16][17][18] Venous congestion could be ameliorated by injection of recombinant hirurdin. 19 Increasing free flap tolerance to ischemia was assessed by perfusion washout, caspase inhibition, acute adenosine treatment, or University of Wisconsin (UW) solution, a high-molecular-weight organ preservation solution.…”

Secondary Burn Progression Decreased by Erythropoietin*

“…Because of the high intersite variability, the data are given in percentage of baseline (17,18). The surface probe measured microcirculatory blood flow to a depth of approximately 1 mm.…”