Estabilização zigomática e retalho de avanço facial lateral em canino filhote / Zygomatic stabilization and lateral facial advancement flap in a puppy dog

O trauma é frequentemente relatado na rotina clínica de pequenos animais, podendo gerar fraturas de componentes ósseos e lesões de tecidos moles adjacentes. No presente trabalho, objetivou-se relatar o caso de um canino, macho, sem raça definida, de sete meses de idade, vítima de trauma craniomaxilofacial decorrente de mordedura, diagnosticado com fratura e deslocamento de osso zigomático, além de importante laceração de pele. O tratamento estabelecido baseou-se no debridamento da ferida, estabilização cirúrgica de arco zigomático com fios de Nylon e na sutura dos ferimentos de pele causados. Em um segundo tempo cirúrgico, foi realizada enucleação e recobrimento do defeito na órbita com malha cirúrgica de polipropileno, além de remoção de tecido exuberante e confecção de retalho subdérmico de avanço facial lateral para recobrimento do defeito cutâneo. A complicação evidenciada na primeira intervenção cirúrgica foi a deiscência das suturas de pele, enquanto no segundo tempo cirúrgico, não houve sinais de complicações. No pós-operatório, o paciente apresentou evolução clínica satisfatória, recebendo alta médica 21 dias após o segundo procedimento cirúrgico realizado. Tendo em vista a adequada evolução clínica, bem como os reduzidos efeitos colaterais, sugere-se que a conduta clínica e técnicas cirúrgicas adotadas para tratamento do paciente em questão foram efetivas.

Trauma is frequently reported in the small animal clinics, and can lead to fractures of cranial bone components and injuries to the adjacent soft tissues. In the present study, the objective was to report the case of a seven-month-old male mongrel dog, that had a craniomaxillofacial trauma resulting from a bite, characterized by zygomatic bone fracture and displacement, in addition to a major skin laceration. The stablished treatment was based on wound debridement, surgical stabilization of the zygomatic arch with nylon threads and in the suturing of skin wounds. In a second surgical procedure, enucleation was performed and a surgical polypropylene mesh was applied to cover the orbital defect, exuberant tissue was removed and a subdermal advancement flap was used to cover the skin defect. The complication observed in the first surgical intervention was dehiscence of the skin sutures, while in the second surgical procedure, there were no signs of complications. Postoperatively, the patient had a satisfactory clinical recovery, being discharged 21 days after the second surgical procedure. Considering the adequate clinical evolution and the reduced complications, it issuggestedthat the clinical conduct and surgical techniques adopted for the treatment of the patient in question were effective.

The influence of adipocyte-derived stem cells (ASCs) on the ischemic epigastric flap survival in diabetic rats

ABSTRACT Purpose: To assess the effects of adipocyte-derived stem cell (ASC)-injection on the survival of surgical flaps under ischemia in diabetic rats. Methods: Diabetes was induced in 30 male Wistar rats using streptozotocin (55 mg/kg). After eight weeks, epigastric flap (EF) surgery was performed. The animals were divided into control (CG), medium-solution (MG), and ASC groups. The outcomes were: the survival area (SA), the survival/total area rate (S/TR), and expression levels (EL) of genes: C5ar1, Icam1, Nos2, Vegf-a. Results: In the ASC group, compared to CG, we observed improved flap SA (CG-420 mm2 vs. ASC-720 mm2; p=0.003) was observed. The S/TR analysis was larger in the ASC group (78%) than the CG (45%). This study showed an increase in the Vegf-a EL in the ASC group (2.3) vs. CG (0.93, p=0.0008). The Nos2 EL increased four-fold in the ASC group compared to CG, and C5ar1 EL decreased almost two-fold in the ASC group vs. the CG (p=0.02). There was no difference among the groups regarding Icam1 EL. Compared to the MG, the ASC group had a bigger flap SA (720 mm2 vs. 301 mm2, respectively), a bigger S/TR (78% vs. 32%, p=0.06, respectively) and increased EL of Vegf-a (2.3 vs. 1.3, respectively). No difference between ASC-group and MG was seen regarding Nos2 (p=0.08) and C5ar1 (p=0.05). Conclusions: This study suggests that ASCs increase the survival of EF under IR in diabetic rats.

Effect of hyperbaric oxygenation on random rat skin flaps vascularization

ABSTRACT Purpose: To evaluate the effect of hyperbaric oxygenation (HBO) on angiogenesis in random rat skin flaps, by immunoexpression of vascular endothelial growth factor A (VEGF-A). Methods: Forty adult rats were divided into four groups: GE) epilated; GE/HBO) epilated subjected to HBO; GER) epilated submitted to dorsal skin flap; GER/HBO) epilated subjected to dorsal skin flap + HBO. HBO was performed with rats inside a chamber under atmosphere close to 100% oxygen and pressure of 2.4 absolute atmospheres, 2h per day during seven consecutive days. GE and GER groups were placed in the hyperbaric chamber without HBO. Then, under anesthesia, skin flaps were removed and separated into three portions relative to pedicle fixation. The samples were fixed in formalin and processed for paraffin embedding. Histological sections were submitted to immunohistochemistry for VEGF-A detection. The number of immunostained-blood vessels were counted under light microscopy. Results: GE and GE/HBO groups showed normal and similar skin morphology in the three flap portions. A fibrin-leukocyte crust, along with denatured collagen and intense leukocyte infiltrate, was mainly observed in the dermis of the medial and distal flap portions of GER group. Meanwhile, the GER/HBO group presented more regions with intact collagen and small areas of leukocyte infiltrate in the three flap regions. VEGF-A-immunostained blood vessels were largely seen in all regions of GE and GE/HBO groups, whereas no significant differences were found between these groups. A decrease in vascularization was noticed in GER and GER/HBO groups, which was more evident in the most distal portion of the flaps. However, the number of VEGF-A-immunostained blood vessels in GER/HBO group was significantly higher when compared to GER group. Conclusions: Hyperbaric oxygenation was associated with increased angiogenesis and improved viability of rat skin flaps.

Skin graft associated with platelet-rich plasma in correcting extensive injuries resulting from the resection of skin cancer chemically induced in rats

ABSTRACT Purpose: To evaluate whether using platelet-rich plasma (PRP) in the graft recipient bed after the resection of a neoplasia can influence its recurrence because this product stimulates angiogenesis, mitogenesis and chemotaxis. Methods: A study with 30 rats Wistar (Rattus norvegicus albinus), which were separated into group A (induction of carcinogenesis, PRP in the postoperative period) and group B (induction of carcinogenesis, absence of PRP in the postoperative period), with 15 animals in each. Carcinogenesis was induced on the skin of the animals' chest by the topical application of 0.5% dimethylbenzantracene (DMBA) diluted in acetone. After surgical resection of the induced neoplasia, PRP was used to stimulate angiogenesis before surgical wound synthesis. Data on the control and experimental groups and macroscopic and microscopic variables were evaluated using analysis of variance and the Tukey's test (5%). Results: It was possible to determine that the use of PRP is good in reconstructive surgeries, but it is contraindicated in patients during tumor resection, as it can cause changes in the surgical bed, in addition to stimulating recurrences and metastases. Conclusions: PRP may interact with tumour cells that were in the recipient site of the surgical wound during the resection of a neoplasia, and a local recurrence process can be triggered by applying this product.

Benefits of pentoxifylline for skin flap tissue repair in rats

Purpose To assess the action of pentoxifylline, administered by subcutaneous route, on skin flap tissue repair in rats, and to verify the histological aspects and biomarkers. Methods Thirty-two male Wistar rats were divided into four groups: control (CT) and treated with pentoxifylline (P1, P3 and P5). Modified McFarlane technique flap was used. Ten days later, the animals were euthanized and the areas of viable and necrotic tissue were evaluated. Hematoxylin/eosin staining was used to assess the morphometric characteristics of the number of vessels and epithelial thickness. Picrosirius red was used to assess collagen density. VEGF and TGF-beta1 levels on the skin flap and serum of the animals were measured by the ELISA method. Results The macroscopic evaluation of the skin flap dimensions showed reduced necrotic tissue in the pentoxifylline (p < 0.05) treated groups. There was an increase in angiogenesis and reepithelization, demonstrated by analyses with an increased number of vessels (p 0.05), VEGF and epithelial thickness. Fibrogenic effect showed decreased collagen density and TGF-1 in the skin flap and serum. Conclusion The benefits of pentoxifylline administered by subcutaneous route, at dose 100 mg/kg, which was effective to improve the survival of skin flap by acting on tissue repair components, stimulating angiogenesis and reepithelization, in addition to reducing fibrogenesis.(AU)

The effect of intradermal administration of inactive platelet-rich plasma on flap viability in rats

Purpose: To evaluate the effect of inactive form of platelet rich plasma (PRP) on the flap viability. Methods: Thirty six rats were used. Rats were divided into six groups then 9x3 cm random pattern skin flaps were elevated from dorsum of all rats. For precluding vascularization from the base, a silicone layer was placed under the flap in groups 2(only flap+silicone), 4(saline+silicone) and 6(PRP+silicone). In groups 1(only flap), 2(only flap+silicone) nothing was done except flap surgery. In groups 3(saline) and 4(saline+silicone), saline was applied intradermally , in groups 5(PRP) and 6(PRP+silicone), inactive form of PRP which obtained from different 16 rats was applied intradermally, into certain points of flaps immediately after surgery. After 7 days flap necrosis ratio was measured in all groups. Results: Mean necrosis rate in group 5(PRP) (16.05%) was statistically significantly lower than group 1(only flap) (31,93%) and group 3(saline) (30,43%) (p 0.001). Mean necrosis rate in group 6(PRP+silicone) (36.37%) was statistically significantly lower than group 2(only flap+silicone) (47.93%) and group 4(saline+silicone) (45.65%) (p 0.001). Conclusion: Intradermal inactive platelet rich plasma administration decreases flap necrosis so for skin application.(AU)

Effects of insulin-like growth factor-1 on random pattern skin flap survival in rats

PURPOSE:To investigate the effects of pharmacological delay with insulin-like growth factor-1 (IGF-1) on skin flap survival.METHODS:Thirty Sprague-Dawley rats were submitted to dorsal skin flap (3x9 cm). Seven days before the surgery, the animals were subdivided into three groups of 10 rats. In group 1 (controls), no injection was done. Seven days before the elevation, saline had been injected to the marked skin flap area in group 2 (sham group), and group 3 (experimental group) underwent a pharmacological delay with subcutaneous IGF-1 injections. On the seventh postoperative day, flap area was analyzed for survival. Tissue samples were obtained for histological and biochemical evaluations.RESULTS:Survival rates were 43.55 ± 16%, 21.40 ± 8%, and 43.12 ± 14% in groups 1, 2, and 3, respectively. Differences between group 2 and other groups were statistically significant. No significant difference was detected between all three groups for tissue or plasma vascular endothelial growth factor (VEGF) levels. There was no significant histological difference between groups.CONCLUSION:Although a single injection of insulin-like growth factor-1 (IGF-1) did not significantly increase flap survival, its wound healing features are still encouraging and further meticulously planned studies, especially with repeated applications or controlled-release methods, and combinations with binding protein are required.(AU)

The positive effect of Botulinum toxin type A on the viability of random flap in tobacco exposed in rats

PURPOSE:To evaluate the effect of Botulinum Toxin A in different time of tobacco exposure.METHODS:60 male, Wistar rats were divided into two tobacco exposure groups: a 2- month or a 4-month regimen. After this period, these two groups were subdivided as two: saline solution(SS) or botulinum toxin A(Bonta), at the time of the surgery. Seven days before the SS or Bonta injection, the animals were submitted to a random flap (3x10cm). On the seventh postoperative day, all animals were assessed for total flap area, viable area, and the viable/ total area ratio.RESULTS:This study showed a difference between groups 2-month saline vs. BontA injection (p=0.04); groups 4-month saline vs. BontA injection (p=0.001); groups 2-month saline vs. 4-month BontA (p=0.003), and, between groups 2- month BontA vs. 4-month saline(p=0.03).CONCLUSIONS:Botulinum Toxin A increased random flap viability in tobacco-exposed rats. Two months of tobacco exposure had the same effect as exposure for four months.(AU)

LASERTERAPIA DE BAIXA INTENSIDADE NA AMPLIAÇÃO DAS DIMENSÕES DE RETALHOS SUBDÉRMICOS EM RATOS WISTAR

Atualmente houve aumento significativo de pacientes oncológicos atendidos na rotina Veterinária. A principal forma de controle de diversos neoplasmas é com a ressecção cirúrgica, e devido à excisão de grandes neoplasmas, é comum a confecção de extensos defeitos, aumentando a indicação de cirurgias reconstrutivas. Novas técnicas para síntese dos defeitos criados passaram a serem utilizadas na Medicina Veterinária, como o uso de retalhos ou enxertos. Na confecção de retalhos subdérmicos, uma das limitações é a proporção entre comprimento e largura do retalho, pois o comprimento não deve passar a proporção de 2,5:1, pois com o aumento desta proporção, eleva o risco de complicações no pós operatório. Sendo assim, novas maneiras para aperfeiçoar esta modalidade e melhorar a reparação tecidual no pós-operatório vem sendo pesquisadas, como por exemplo, a Laserterapia de Baixa Intensidade (LBI). Este trabalho teve como objetivo avaliar a eficácia da LBI em duas dosagens diferentes, afim de aumentar a proporção na extensão da confecção de retalhos subdérmicos, que atualmente é limitada à 2,5:1 (comprimento x largura). Foram utilizados 24 ratos (Rattus norvergicus albinus wistar), sendo cada um submetido à confecção de retalho cutâneo em seu dorso, distribuídos de forma aleatória em três grupos (Controle sem a terapia da LBI, grupo na dose de 4J/cm² e grupo na dose de 6J/cm²). Os dois grupos que foram irradiados pela terapia à laser sobre o retalho nos dias D0 (dia do procedimento cirúrgico), D2, D4 e D6. A avaliação macroscópica foi realizada aos dias três e sete não mostrou alteração de acordo com o tratamento estabelecido. A avaliação microscópica com a análise histopatológica não apontou diferença estatística entre os grupos. Conclui-se que a exposição de retalhos cutâneos à dose de energia 4J/cm² e 6J/cm² a cada 48 horas não interfere perceptivelmente sobre a cicatrização e a inflamação local, não contribuindo para o aumento da proporção do retalho.

Currently, there has been a significant increase in cancer patients treated in the veterinary routine. The main form of control of several neoplasms is with surgical resection, and due to the excision of large neoplasms, it is common to make extensive defects, increasing the indication for reconstructive surgery. New techniques for synthesizing the created defects started to be used in Veterinary Medicine, such as the use of flaps or grafts. In the manufacture of subdermal flaps, one of the limitations is the proportion between length and width of the flap, as the length should not exceed the proportion of 2.5:1, as the increase in this proportion increases the risk of complications in the postoperative period. Thus, new ways to improve this modality and improve tissue repair in the postoperative period have been researched, such as Low-level Laser Therapy (LLL). This study aimed to evaluate the effectiveness of LLLT at two different dosages, in order to increase the proportion in the extension of subdermal flaps, which is currently limited to 2.5:1 (length x width). Twenty-four rats (Rattus norvergicus albinus wistar) were used, each one submitted to a skin flap on its back, randomly distributed into three groups (Control - without LLL therapy, 4J/cm² dose group and no group dose of 6J/cm²). The two groups that were irradiated by laser therapy over the flap on days D0 (day of the surgical procedure), D2, D4 and D6. The macroscopic evaluation was carried out on days three and seven, showing no change in accordance with the established treatment. Microscopic evaluation with histopathological analysis showed no statistical difference between groups. It is concluded that the exposure of skin flaps to the dose of energy 4J/cm² and 6J/cm² every 48 hours does not perceptibly interfere with healing and local inflammation, not contributing to the increase in the proportion of the flap.

Analysis of effect isoxsuprine hydrochloride and nicotine in the Transverse Rectus Abdominis Myocutaneous flap (TRAM) in rats

PURPOSE: To evaluate the effects of isoxsuprine and nicotine on TRAM. METHODS: Forty eight 48 Wistar rats distributed into four Groups (n=12). All rats received medication managed daily for 20 days: saline solution (SA), nicotine solution (NI), isoxsuprine solution (IS) and nicotine solution (NI) + isoxsuprine solution (IS). On day 21st the rats were submitted to the caudally based, right unipedicled TRAM flap and after 48 hours, made the macroscopic evaluation of the surface of the flap, photographic documentation and collection of material for histology. Data from macroscopic evaluation were analyzed by ANOVA and microscopic evaluation by Kruskal-Wallis test, with significance level of 5%. RESULTS: In the macroscopic evaluation of isoxsuprine Group retail presented absolute numbers: final area (p=0.001*) and viable area (p=0.006*) with the highest values; necrosis (p=0.001*) had the lowest value. Microscopic examination revealed no significant findings in the study of TRAM under the action of isoxsuprine and nicotine to the percentage of necrosis in the left and right cranial and caudal regions. CONCLUSIONS: There was significant improvement in viability of TRAM using the isoxsuprine solution alone. No influence using nicotine alone and in association with isoxsuprine.(AU)

Botulinum toxin type A on cutaneous flap viability in diabetic and tobacco-exposed rats

To investigate the effect of Botulinum toxin A (BoNTA) on skin flap viability in healthy, tobacco-exposed and diabetic rats. Ninety male Wistar rats (250-300g) were randomly divided into six groups: control+saline (C1), control+BoNTA (C2), tobacco-exposed+saline (T1), tobacco-exposed+BoNTA (T2) diabetes+saline (D1) and diabetes+BoNTA (D2). A dorsal cutaneous flap (3×10cm) was performed. Survival area and total area of the flaps were measured. Lumen diameter, external arterial diameter and lumen/wall thickness ratio were recorded. Survival area increased in control group with BoNTA injection compared with control animals injected with saline (C2 x C1; 0.9±0.1 vs0.67±0.15, p= 0.001). A similar result was found in diabetes group injected with BontA (D2 x D1; 0.97±0.2 vs0.61±0.24, p=0.018). No difference was observed in skin flap viability in tobacco-exposed groups (T2 x T1; 0.74±0.24 vs 0.64±0.21, p=0.871). Lumen diameter (p= 0.004), external arterial diameter (p = 0.0046,) and lumen/wall thickness ratio (p= 0.003) were increased in diabetes+BoNTA-treated animals. This effect was not observed in control or in tobacco-exposed groups. Botulinum toxin A increased skin flap viability in control and diabetic rats on the seventh post-operative day. Increased lumen diameter, external arterial diameter, and lumen/wall thickness ratio were observed in the diabetes+BoNTA group. BoNTA had no effect in the tobacco-exposed group on the seventh postoperative day.(AU)

Histological modification in TRAM flap in rats treated with pentoxifylline

To investigate the blood vessels' concentration in TRAM flap's rat model, in the presence of pentoxifylline. 32 male, Wistar-EPM rats were divided into two groups. Control group (C): 0.5 ml of saline, intraperitoneally, once a day, for seven days before flap elevation; PTX group (P): pentoxifylline (20mg/kg/day), intraperitoneally, for seven days before flap elevation. After that, they were submitted to a caudal unipedicle TRAM flap. On the fifth postoperative day, percentages of flap necrosis were determined via the "paper template" method and Tram flap's zone IV skin biopsies were taken for histological analysis. The mean percentage of flap necrosis in group C was 58.7 % and in group P, 31.1 (Wilcoxon test; p = 0.003). Mean capillary vessels number in zone IV's skin in C group was 33.4 and in P group was 71.9 (p=0.008). Pentoxifylline was effective reducing the necrosis in the caudal unipedicle TRAM flap in the rat as well as increasing the number of capillaries in an ischemic zone (zone IV).(AU)

Description of a new experimental model skin flap for studying skin viability in rats

To describe a new experimental flap for studying skin viability in rats. METHODS: Twenty male Wistar rats weighing between 250-300g were divided into two groups: group A - McFarlane technique, a 4 x 10cm flap was used (McFarlane); and in group B modified McFarlane technique, a 3 x 10cm flap was used. Seven days later, the animals were sacrificed and the area of necrosis was evaluated in both groups. RESULTS: Group A presented necrosis in 3% of the total area of the flap (CI: 0.01-0.05), Group B presented necrosis in 37% of the total area of the flap (CI: 0.29-0.46), (p<0.001). CONCLUSION: The modified McFarlane flap presented a larger area of necrosis and could be an adequate experimental model of skin flap viability.(AU)

Adipose-derived stem cells (ADSC) in the viability of a random pattern dorsal skin flap in rats

To evaluate the viability of random pattern dorsal skin flaps in rats after injection of adipose-derived stem cells (ADSC). Thirty five adult male Wistar EPM rats (weight 250-300 g) were distributed, at random, in two groups. I- Control (flap elevation with injection of saline solution) with fifteen animals and II- Experimental (flap elevation with injection of ADSC ) with fifteen animal. The ADSC were isolated from others five adult male rats. A dorsal skin flap measuring 10x4 cm was raised and a plastic barrier was placed between the flap and its bed in both groups and the injection (cells or saline solution) were perfomed immediately after the surgery. The percentage of flap necrosis was measured on the seventh postoperative day. The ADSC were able to replicate in our culture conditions. We also induced their adipogenic, osteogenic and chondrogenic differentiation to verify their mesenchymal stem cells potentiality in vitro. The results were statistically significant showing that the ADSC decreased the area of necrosis (p<0.05). CONCLUSIONS: The cells demonstrated adipogenic, osteogenic and chondrogenic differentiation potential in vitro. The administration of adipose-derived stem cells was effective to increase the viability of the random random pattern dorsal skin flaps in rats.(AU)

Experimental model of obtaining tissue adipose, mesenchymal stem cells isolation and distribution in surgery flaps in rats

PURPOSE: To investigate the experimental model for obtaining adipose tissue, isolation, characterization of mesenchymal stem cells and evaluation of their distribution in the tram flap in rats. METHODS: Five rats of Wistar were randomly assigned to two groups. In group I, three animals underwent removal of adipose tissue in the groin procedure to establish the experimental model and obtain a cell lineage. The animals of group II (n = 2) underwent surgical flap procedure, and satisfaction injection of mesenchymal stem cells pretreated with marker fluorescente. RESULTS: obtaining adipose tissue of the inguinal region of the rat proved to be possible. The isolated cells were characterized as mesenchymal stem cells and fluorescence microscopy showed the presence of multiple cells arranged around blood vessels and capillaries. CONCLUSION: It was possible to establish an experimental model for obtaining adipose tissue for isolation of mesenchymal stem cells and their distribution in the TRAM flap in rats.(AU)

Adipose-derived stem cells (ADSC) in the viability of random skin flap in rats

To evaluate the effects of the adipose-derived stem cells (ADSC) in the viability of random skin flap in rats. Thirty five adult male Wistar rats (weight 250-300 g) were used. ADSC were isolated from adult male rats (n=5). ADSC were separated, cultured and then analyzed. A dorsal skin flap measuring 10x4 cm was raised and a plastic barrier was placed between the flap and its bed. After the surgical procedure, the animals were randomized into two groups (n=15 each group), group control and group ADSC. In all groups the procedures were performed immediately after the surgery. The percentage of flap necrosis was measured on the seventh postoperative day. The ADSC were able to replicate in our culture conditions. We also induced their adipogenic, osteogenic and chondrogenic differentiation, verifying their mesenchymal stem cells potentiality in vitro. The results were statistically significant showing that the ADSC decreased the area of necrosis (p<0.05). CONCLUSION: The cells demonstrated adipogenic, osteogenic and chondrogenic differentiation potential in vitro. The administration of adipose-derived stem cells was effective to increase the viability of the random skin flaps in rats.(AU)

Effects of the topical administration of copaiba oil ointment (Copaifera langsdorffii) in skin flaps viability of rats

PURPOSE: To evaluate the effects of copaiba oil ointment (Copaifera langsdorffii) on dorsal skin flaps in rats. METHODS: Adult male rats (n=30) were distributed into three groups of ten animals each, as follows: GC - control; GCA - absolute control and GT - treated with copaiba ointment. The rats were subjected to dorsal cutaneous skin flap surgery and the animals from the GC and GT received post-operative treatment for eight consecutive days. The animals from the GCA group did not receive treatment while the animals from the GC group received daily topical treatment of ointment without the active ingredient and the animals from the GT group were daily treated with 10% copaiba oil ointment. At the end of each experimental period the lesions were evaluated according to the percentage of necrotic area. Then, fragments from cranial, median and caudal parts were fixed in Boüin's solution and processed for paraffin embedding. The morphology of histological sections (5µm) was evaluated and the number of leucocytes, fibroblasts and blood vessels was also analyzed. The data obtained were submitted to ANOVA test complemented by Tukey-Kramer test (p<0.05). RESULTS: The necrotic area was lower in the group treated with copaiba ointment when compared to the control groups (GCA>GC and GT), while the morphology showed larger granulation tissue with bulky fibroblasts and collagen fibers more arranged in the GT group. The morphometry showed a significant higher number of blood vessels in the median and caudal parts (GT>GCA and GC), leucocytes in the cranial part (GT>GC>GCA), and also fibroblasts in the median (GT and GC> GCA) and caudal parts (GT>GC and GCA) (p<0.05). CONCLUSION: The copaiba oil ointment favors angiogenesis and accelerates the viability of random skin flaps in rats.(AU)

The influence of type of vascular pedicle occlusion on the viability of skin island flaps: a postoperative quantitative assessment of flap survival in an experimental model in rats

PURPOSE: To evaluate the role of pedicle occlusion on the viable area of a skin island flap. METHODS: An epigastric skin island flap was performed in 160 Wistar rats. The animals were randomly divided into four groups: G-1: occlusion of inferior epigastric artery; G-2: inferior epigastric vein; G-3: inferior epigastric vessels (artery/vein). At varying times postoperatively (2,3,4,5th day), animals from each group were randomly selected, and the pedicle was occluded. On the 10th. postop. day, the skin flaps were evaluated by templates to determine the percentage of surviving skin. The computer HP™ 9830A captured the photographs and the mean flap necrosis area was assessed. RESULTS: An increasing area of flap survived with less area of necrosis with increased time of days intervals. In the G-1, the mean area of necrosis observed (two to five days) were 95.2, 60.8, 31 and 3.7 % respectively. In the G-2 were 95.5, 57.6, 19.5 and 5.6 % respectively. In the G-3, a 100, 80, 32.4 and 14.9 % of mean area was observed. CONCLUSIONS: The arterial suppy/venous drainage is important for flap circulation up to five days following pedicle occlusion. After this period, the pedicle can be interrupted once the circulation through the flap margins has already been established.(AU)

Galea and periosteum flap filled with bone fragments in rabbits

PURPOSE: To study the bone viability of a vascularized galea and periosteum flap filled with bone fragments, as a substitute of the bone graft in facial reconstructive surgery. METHODS: Forty rabbits were studied, and divided in two groups. One had a simple galea and periosteum flap done and the other had the same flap done and filled with bone fragments of the calvaria. The bone formation was evaluated by radiographies, macroscopic and microscopic analysis. RESULTS: The bone neoformation in both groups with differences in bone morphology and structure especially at histological analysis. CONCLUSION: This study demonstrated osseous formation in both groups of galea and periosteum flaps, with and without bone fragments.(AU)

The effects of local nitroglycerin on the surgical delay procedure in prefabricated flaps by vascular implant in rats / Efeitos da nitroglicerina tópica na autonomização de retalhos pré-fabricados por implante vascular em ratos

PURPOSE: To evaluate the effect of local nitroglycerin on the viable area of a prefabricated flap for vascular implant in rats, and to investigate the surgical delay procedure. METHODS: A femoral pedicle was implanted under the skin of the abdominal wall in forty Wistar rats. The animals were divided into four groups of ten: group 1 - without surgical delay procedure and local nitroglycerin; group 2 - with surgical delay procedure, but without local nitroglycerin; group 3 - without surgical delay procedure, but with local nitroglycerin; and group 4 - with simultaneous surgical delay procedure and local nitroglycerin. The percentages of the viable areas, in relation to the total flap, were calculated using AutoCAD R 14. RESULTS: The mean percentage value of the viable area was 8.9% in the group 1. 49.4% in the group 2; 8.4% in the group 3 and 1.1% in the group 4. There was significant difference between groups 1 and 2 (p=0.005), 1 and 4 (p=0.024), 2 and 3 (p=0.003), 2 and 4 (p=0.001). These results support the hypothesis that the closure of the arterial venous channels is responsible for the phenomenon of surgical delay procedure. CONCLUSION: Local nitroglycerin did not cause an increase in the prefabricated viable flap area by vascular implantation and decreased the viable flap area that underwent delay procedures.(AU)

OBJETIVO: Avaliar o efeito da nitroglicerina tópica sobre a área viável de um modelo de retalho pré-fabricado por implante vascular em ratos e analisar o mecanismo de autonomização cirúrgica aplicada a retalhos pré-fabricados. MÉTODOS: Foram utilizados 40 ratos Wistar. No primeiro tempo cirúrgico - 20 ratos foram submetidos a implante do pedículo femoral na região subdérmica da parede abdominal, e 20 submetidos à autonomização cirúrgica de retalho cutâneo de parede abdominal e, simultaneamente, implante do pedículo femoral na região subdérmica deste retalho. No segundo tempo - após três semanas e em todos os animais, era elevado um retalho cutâneo ilhado, pediculado unicamente nos vasos implantados e divididos em quatro grupos de dez animais: grupo 1, com retalhos submetidos unicamente a implante do pedículo femoral na região subdérmica da parede abdominal; grupo 2, com retalhos submetidos à autonomização cirúrgica e implante do pedículo femoral na região subdérmica deste retalho; grupo 3, com retalhos submetidos unicamente a implante do pedículo femoral na região subdérmica da parede abdominal tratados com nitroglicerina tópica; grupo 4, com retalhos submetidos à autonomização cirúrgica e implante do pedículo femoral na região subdérmica deste retalho tratados com nitroglicerina tópica. O percentual de área viável, em relação à área total do retalho, foi calculado sete dias após o segundo tempo cirúrgico. RESULTADOS: O valor médio de área viável alcançou 8,9% no grupo 1; 49,4% no grupo 2; 8,4% no grupo 3; e 1,1% no grupo 4. Houve diferença significante entre os grupos 1 e 2 (p=0,005); 1 e 4 (p=0,024); 2 e 3 (p=0,003) e 2 e 4 (p=0,001). Os resultados fortaleceram a hipótese de que o fechamento dos canais arteriovenosos é o principal mecanismo responsável pelo aumento da área viável observada em retalhos submetidos à autonomização cirúrgica.CONCLUSÃO: A nitroglicerina tópica não induziu ao aumento da área viável dos retalhos pré-fabricados por implante vascular e diminuiu a área viável dos retalhos submetidos à autonomização.(AU)