[The influence of vacuum-assisted drainage on the growth of capillaries in the wound produced by explosion in pig].
OBJECTIVE
To investigate the influence of vacuum-assisted closure (VAC) technique on the growth of capillaries in the wound of the pig produced by explosion.


METHODS
Four small white pigs were inflicted with 16 explosion wounds [(7.3 +/- 1.0) cm2 in area] on both sides of the buttocks, shoulders and hips by detonation of a specific type of explosive, and the wounds were randomly divided into 2 groups, i. e, control (C, with conventional treatment from 2 post-injury day (PID) on and treatment (T, with VAC treatment after debridement from 2 PID on) groups, with 8 wounds in each group. Wound tissues of 2mm x 2mm x 2mm in size were harvested for pathological examination before treatment and on 1 and 3 post-treatment day (PTU). The differentiation of adventitial cells were examined with light microscope, and the pixel value of desmin positive particles and the luminal area of newly formed capillaries were assessed with Image C software.


RESULTS
Most of vessels in the wound of both groups were in elliptic shape when observed in longitudinal section. In C group, few newly formed capillaries vessels with lack of pericytes were observed before treatment and on 1, 3 PTD, then the number began to increase on 6 PTD. In T group, the number of newly formed capillaries with pericytes was increased on 1 PTD, and it continued to increase thereafter. The pixel values of desmin positive particles in C group on 1, 3, and 6 PTD were (91 +/- 54), (199 +/- 85), and (1552 +/- 298), respectively, which were obviously higher than those in T group [(2569 +/- 330), (3984 +/- 377), (9611 +/- 960), P < 0.01]. The area of vessel lumen in C group was (59 +/- 36), (250 +/- 70), and (938 +/- 287) microm2, respectively on 1, 3, and 6 PTD, which was also smaller than those in T group [(818 +/- 234), (4518 +/- 1080), and (9058 +/- 1656) microm2, P < 0.01].


CONCLUSIONS
Compared with conventional therapy, VAC can not only accelerate the formation of new capillaries, but also enhance the differentiation of pericytes and the process of enwrapping them around the vessels, and increase the luminal area of newly formed capillaries.
Li
Xue-yong
XY
Department of Burns and Plastic Surgery, Tangdu Hospital, Fourth Military Medical University, Xi'an, P. R. China.
Li
Wang-zhou
WZ
Li
Yue-jun
YJ
Lv
Xiao-xing
XX
Li
Jing
J
Chen
Shao-zong
SZ
Li
Jin-qing
JQ
D000818:Animals; D001753:Blast Injuries / Q000628:therapy*; D002196:Capillaries / Q000166:cytology / Q000254:growth & development*; D005260:Female; D008297:Male; D054843:Negative-Pressure Wound Therapy; D018919:Neovascularization, Physiologic; D013552:Swine; D014945:Wound Healing