PURPOSE: This study investigated the morphological characteristics of hypertrophic scars of various ages. METHODS: This was a retrospective study. Tissue samples from 170 normal skin (control) and 126 scar tissue after undergoing conservative treatment (CT) (n=62) or split thickness skin graft (STSG) (n=64) were obtained. Time from injury (CT) or surgery (STSG) was grouped into periods as follows: first 6 months (period 1), 7~12 months (period 2), 13~24 months (period 3), 25~120 months (period 4), >120 months (period 5). Epidermal thickness (ET), dermal thickness (DT), and dermal collagen fiber thickness and length (CFT, CFL) were measured using an image analyzer. RESULTS: Scar tissue ET was significantly thicker compared to normal skin (P<0.05) and was greatest at period 1. Scar tissue DT was significantly thicker compared to normal skin (P<0.05), which increased until period 3 but then decreased afterwards. Scar tissue CFT was significantly thinner compared to normal skin (P<0.05) except for period 5. Scar tissue CFL was significantly longer compared to normal skin (P<0.05). Significant differences were observed especially in younger scar ET, DT, CFT, and CFL. CONCLUSION: These findings may assist to increase the understanding of the pathohistological changes in burn scar tissues over time and provide guidance in receiving burn treatment.
Burns ; Cicatrix* ; Cicatrix, Hypertrophic* ; Collagen ; Pathology ; Retrospective Studies ; Skin ; Transplants

OBJECTIVETo investigate the effect of HMME-PDT (Hematoporphyrin Monomethyl Ether-Photodynamic therapy) on Hyperplastic scar in the rabbit ear.

METHODSThe acute model of dermal Hyperplastic scar in the rabbit ear was established. 24 scars were randomly divided into 2 groups: the experimental group (n = 12) received HMME-PDT treatment, and the controlled group (n = 12) received no special treatment. Specimens were harvested from scars on postoperative 28 day. Scar hyper plasty and collagen fibers were observed by haematoxylin-eosin staining and Van-Gieson staining respectively. The microvessel density was calculated under microscope.

RESULTSCompared with the controlled group, HMME-PDT treatment in the experimental group reduced scar formation, decreased the microvessel density and prevented excess collagen deposition at the wound site.

CONCLUSIONSHMME-PDT may play a role in inhibiting hyperplastic scar in rabbit ear.

Animals ; Cicatrix, Hypertrophic ; pathology ; therapy ; Ear ; pathology ; Female ; Hematoporphyrins ; pharmacology ; Male ; Photochemotherapy ; Rabbits

UNLABELLEDTo further explore the relationship between hypertrophic scar and injury to conical structure of skin and the pathogenesis of hypertrophic scar, and to reproduce an optimal animal model of hypertrophic scar.

METHODSThe back of two FRDP pigs were shaved, and a piece of normal skin was harvested for the observation of conical structure of skin. Skin wounds with depth of 0.38 mm, 0.76 mm, 1.14 mm and 1.52 mm, respectively, were created by gas-driven dermatome. Eight wounds measuring 7.0 cm x 7.0 cm were created on each pig. The wounds were divided into 4 groups according to the wound depth with 4 wounds in each group, i.e. 0.38 mm group, 0.76 mm group, 1.14 mm group and 1.52 mm group. The 0.38 mm and 0.76 mm groups were designated as superficial wound groups and 1.14 mm and 1.52 mm groups as deep wound groups. The wounds were allowed to heal without treatment. Tissue samples from the wound were harvested on 0, 10, 30, 60, 90 and 150 post injury day (PID) , and they were sectioned for HE staining and staining for elastic fibers (VVG). The wound healing and the scar formation were observed with naked eye. The skin conical structures in normal and injured skin were also observed. The morphology of hypertrophic scar was observed, and the thickness of the scar tissue was determined and scored.

RESULTSThe wounds in superficial wound groups healed within 3 weeks with flat surface without scar formation. The wounds in deep wound groups healed later than 4 weeks with thick, hairless, hard in texture, with depigmentation or pigmentation, finally forming contracture. The skin conical structure could be found on the back of FRDP with HE and VVG staining, and it was similar to that of human in terms of the structure. In superficial wound groups, the upper part of the skin conical structure was injured, but fat fornix and glands were intact. In deep wound groups, the lower part of the skin cone, together with the fat fornix and gland were all injured. On the 150th post injury day, the histological picture of the tissue in superficial wound groups was similar to that of normal skin. But the skin conical structure could not be found in deep wound groups, and the wounds were filled by a large accumulation of disarrayed and irregularly arranged collagen fibers. With passage of time, the scar became thicker and thicker, and the scar hypertrophy reached the zenith in 150th PID.

CONCLUSIONThe injury of skin conical structure can lead to the formation of hypertrophic scar. FRDP can be used to reproduce and ideal model of hypertrophic scar.

Animals ; Cicatrix, Hypertrophic ; etiology ; pathology ; Disease Models, Animal ; Female ; Hyperplasia ; Skin ; injuries ; pathology ; Swine

OBJECTIVETo investigate the feasibility of reproduce hypertrophic scar and keloid in nude mice in the study of pathological scars.

METHODSPieces (0.8 x 0.8 x 0.5 cm) of hypertrophic scars and keloids were implanted into subcutaneous tissue of the nude mice for 16 days, during this period the gross condition of the nude mice and the state of the implants were observed. The implants were extracted after 16 days, and the volume, the microscopic characteristics of the scar, the content of acid mucopolysaccharide, and different types of collagen were determined and compared with that of the original specimens.

RESULTSAll mice survived with nice wound healing after the surgery. There was no obvious difference in the acid mucopolysaccharide content in keloid and hyperplastic scar before implantation (3448 +/- 1452, 1940 +/- 509), and after implantation (3237 +/- 1871, 1809 +/- 552, P > 0.05). The implants maintained the collagen pattern, with no signs of cell degeneration and necrosis.

CONCLUSIONThis experiment showed that the viability and morphology of hypertrophic scars and keloids were maintained after they were implanted in nude mice. Therefore it is feasible to use nude mice as the animal model in the study of hypertrophic scars and keloids.

Animals ; Cicatrix, Hypertrophic ; pathology ; Disease Models, Animal ; Keloid ; pathology ; Mice ; Mice, Inbred BALB C ; Mice, Nude

Hypertrophic scar is a pathological repair result of excessive accumulation of extracellular matrix after skin damage, which affects the appearance and function of patients with varying degrees. The degree of scar formation is directly related to the strength of inflammatory reaction during wound healing, and excessive or prolonged inflammatory response increases the incidence of hypertrophic scars. Interleukin-6 (IL-6) is a pleiotropic cytokine that is involved in regulating the fibrotic network composed of fibroblasts, macrophages, keratinocytes, and vascular endothelial cells, and is closely related to the formation of hypertrophic scars. This article reviews the role of IL-6 and its signaling pathway in hypertrophic scar formation.
Cicatrix, Hypertrophic/pathology* ; Endothelial Cells/metabolism* ; Fibroblasts/metabolism* ; Humans ; Interleukin-6 ; Skin/pathology* ; Wound Healing/physiology*

OBJECTIVETo study the expression of P57(kip2) and Maspin in the pathological scar and their possible role in the pathogenesis of abnormal scars.

METHODSImmunohistochemistry integrated image analysis and reverse transcription polymerase chain reaction (RT-RCR) were performed to detect the expression of P57(kip2) and Maspin in hypertrophic scar, keloid, mature scar and normal skin. Statistics was used to analyze the datas.

RESULTSThe expression of P57(kip2) protein was fixed to fibroblast intranuclear in abnormal scar, and the expression of P57(kip2) protein and P57(kip2) mRNA decreased (P < 0.05). The expression of Maspin protein was fixed to fibroblast cytoplasm and intranuclear in abnormal scar, and the expression of Maspin protein and Maspin mRNA decrease, compared with that in normal group (P < 0.05). There was positive correlation between P57(kip2) protein and Maspin protein expression (P < 0.01).

CONCLUSIONSThe decreased expression of P57(kip2) and Maspin in abnormal scar shows that they are cicatrix-related genes. There is a positive relationship between the two genes. It may be one of the mechanisms of pathogenesis of abnormal scar. It makes effect through fibroblasts.

Cicatrix ; metabolism ; pathology ; Cicatrix, Hypertrophic ; metabolism ; pathology ; Cyclin-Dependent Kinase Inhibitor p57 ; metabolism ; Fibroblasts ; metabolism ; Humans ; Serpins ; metabolism

OBJECTIVETo explore the influence of dermal defect and fat dome structure destruction in burn wounds on the formation of hyperplastic scar.

METHODSFifty two wounds in 24 burn patients with deep partial thickness burn indicating tangential excision in the extremities were enrolled in the study, and they were divided into three groups according to the extent of exposure of dermal fat granules, i.e. A (without fat exposure), B (with little fat exposure) and C (with much fat exposure) groups. These three groups were subdivided into A1 (without grafting), A2 (grafting with razor thin skin), B1 (without grafting), B2 (with razor thin skin grafting), C1 (without grafting) and C2 (with split-thickness skin grafting) groups, with 9 wounds in each group. The dermal depth and exposure rate of the fat granules in each group were measured and analyzed by KS400 photography analysis apparatus. The follow-up conditions of the scars 6 months after operation were evaluated with Vancouver remark system by Vancouver score assessment.

RESULTSThere was obvious difference in the dermal depth and exposure rate of the fat granules among all the groups (P < 0.05 or 0.01). The fat exposure rate was positively correlated with the extent of the dermal defect (gamma = 0.554, P < 0.05). The Vancouver score in group A was lower than that in B and C groups (P < 0.05), while that in B1 group (3.714 +/- 2.498) was evidently higher than that in other groups (P < 0.01). The scar score was lowered when the wounds were grafted with the dermis with its thickness similar to the depth of the defect, The scar score was increased along with the elevation of fat exposure rate (P < 0.05).

CONCLUSIONThere was a positive correlation between the degree of dermal defect and that of hyperplastic scar after burns. The disruption of fat dome structure might also be an important factor in the scar development.

Adipose Tissue ; pathology ; Adult ; Burns ; complications ; pathology ; Cicatrix, Hypertrophic ; etiology ; pathology ; Dermis ; pathology ; Female ; Humans ; Male ; Middle Aged ; Wound Healing

OBJECTIVETo explore the role of collagen degradation and scar morphology and structure in the formation of hypertrophic scar.

METHODSSDS-PAGE (sodium dodecyl sulfate polyacrylamide gel electrophoresis) plus collagen substrate electrophoresis, amino acid analysis and compound staining were employed to observe the collagenase activity within hypertrophic scar, collagen degradation and the tissue morphology of the scar.

RESULTSThere exhibited deranged collagen fibres within hypertrophic scar, and large amounts of acid mucopolysaccharide closely surrounded the collagen fibres. All these led to an obvious decrease in collagenase activity and reduction of collagen degradation.

CONCLUSIONThe decrease of collagen degradation and the formation of hypertrophic scar might be closely related to the decrease in collagenase activity and the inhibiting activity of acid mucopolysaccharide on collagenase.

Adolescent ; Adult ; Child ; Cicatrix, Hypertrophic ; metabolism ; pathology ; Collagen ; metabolism ; Collagenases ; metabolism ; Female ; Humans ; Male

OBJECTIVETo establish an ideal model of human hyperplastic scar (HS) in nude mice, so as to provide us a new model to carry out further studies on the mechanism of HS development.

METHODSFull skin defect sized 2.0 cm x 1.5 cm was created on the back of 100 nude mice. The defect was thereafter covered with full thickness human skin. After the grafted skin survived, the nude mice were subjected to deep partial thickness burn of the grafted skin with heated copper rod. The development of the hyperplasia of the scar after wound healing was observed histologically and grossly.

RESULTSGrafted full-thickness human skin took and survived well in 86 out of 100 nude mice. There was obvious and continuous hyperplasia of scar in 67 mice (78%). The external appearance and histological features of the HS appeared similar to those in human HS. The average thickness of the scar was 0.34 cm, with the thickest part measuring 0.6 cm. In addition, the time of hyperplastic change lasted for 63 - 217 days in average of 128 days.

CONCLUSIONObvious and continuous scar hyperplasia could be found in this model, and the whole process beginning from wound healing to the formation of HS could be easily observed. The model was therefore suitable and ideal for the study of HS.

Animals ; Cicatrix, Hypertrophic ; etiology ; pathology ; Disease Models, Animal ; Female ; Male ; Mice ; Mice, Nude

OBJECTIVE: To investigate the relationshion between the angiogenesis of different kinds of scar and expression of HO-1. METHODS: The expression of heme oxygenase-1 and vessel counted by CD34 of biopsies from different kinds of scars such as hypertrophic scar, keloid, surgical scar and normal skin of 24 cases was valued by immunochemical method, and the relationship was compared between them. RESULTS: The vessel count of hypertrophic scar, keloid was significantly abundant compared with surgical scar or normal skin (P < 0.01). While the expression of HO-1 of hypertrophic scar, keloid was obviously higher than that in surgical scar or normal skin (P < 0.01), decreased from hypertrophic scar, keloid, surgical scar to normal skin. There existed a positive correlation between vessel count and the expression of HO-1 (r = 0. 761, P < 0.01) as well as the number of fibroblastic cells (r = 0. 731, P < 0.01) in the study groups. CONCLUSION HO-1 might play a important role in the angiogenesis of scar formation. The cause of these changes may be local. Over angiogenesis is one symbol of pathological scar.
Adult ; Cicatrix ; metabolism ; pathology ; Cicatrix, Hypertrophic ; metabolism ; pathology ; Female ; Heme Oxygenase-1 ; biosynthesis ; genetics ; Humans ; Keloid ; metabolism ; pathology ; Male ; Middle Aged ; Neovascularization, Pathologic ; Skin ; blood supply