Angiogenic effects of cryosurgery with liquid nitrogen on the normal skin of rats, through morphometric study

Abstract

BACKGROUND Cryosurgery is an efficient therapeutic technique used to treat benign and malignant cutaneous diseases. The primary active mechanism of cryosurgery is related to vascular effects on treated tissue. After a cryosurgical procedure, exuberant granulation tissue is formed at the injection site, probably as a result of angiogenic stimulation of the cryogen and inflammatory response, particularly in endothelial cells.OBJECTIVE To evaluate the angiogenic effects of freezing, as part of the phenomenon of healing rat skin subjected to previous injury.METHODSTwo incisions were made in each of the twenty rats, which were divided randomly into two groups of ten. After 3 days, cryosurgery with liquid nitrogen was performed in one of incisions. The rats' samples were then collected, cut and stained to conduct histopathological examination, to assess the local angiogenesis in differing moments and situations.RESULTS It was possible to demonstrate that cryosurgery, in spite of promoting cell death and accentuated local inflammation soon after its application, induces quicker cell proliferation in the affected tissue and maintenance of this rate in a second phase, than in tissue healing without this procedure.CONCLUSIONS These findings, together with the knowledge that there is a direct relationship between mononuclear cells and neovascularization (the development of a rich system of new vessels in injury caused by cold), suggest that cryosurgery possesses angiogenic stimulus, even though complete healing takes longer to occur. The significance level for statistical tests was 5% (p<0,05).

Liquid nitrogen cryotherapy in recalcitrant alopecia areata: A study of 11 patients

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Case Report: Antiangiogenic Therapy Plus Immune Checkpoint Inhibitors Combined With Intratumoral Cryoablation for Hepatocellular Carcinoma

“…There have been preliminary studies of the effect of cryoablation on the activation of the immune system, but the effect of cryoablation on tumor blood vessels is less well described. It has been reported that cryoablation of normal rat skin can stimulate local angiogenesis, but the resulting neovasculature may not be fully functional ( 25 ). Some studies have found that the expression of vascular endothelial growth factor (VEGF) is up-regulated in tumor tissue after cryoablation, and angiogenesis in residual tumor is significantly increased.…”

Efficacy of superficial cryotherapy on the eyebrows of patients with alopecia universalis also treated with contact immunotherapy on the scalp: a prospective, split‐face comparative study

“…When exposure to hypothermic liquefied nitrogen gas is limited to a short period, no crystal formation or blood flow occlusion occurs. After initial vasoconstriction with cryotherapy, there is a significant local vasodilatation during the thaw period . Moreover, local edema and inflammation occurring after cryotherapy may play a role in inducing vasodilatation .…”