Comparison of three different strategies to treat sciatic nerve regeneration: an experimental study

Purpose: To compare the effect of vein conduit filled with adipose tissue stem cells (ASC) on peripheral nerve injury regeneration. Methods: We analyzed 30 male Wistar rats surgically submitted to a 5-mm gap on the sciatic nerve. Then, the animals were divided into three groups: nerve autografting (AG, n=10), autogenous inverted glycerol-conserved vein (VG, n=10), and autogenous inverted glycerol-conserved vein + ASC (VASCG, n=10). The study endpoints were neuromotor functional analysis, gastrocnemius muscle weight, and sciatic nerve graft histomorphometry analysis. In the histologic analysis, we added a control group (naïve nerve). Results: Regarding functional analysis (Walking tract- score), the findings at week 3 showed a difference between the AG and the VG (-96.6 vs. -59.6, p=0.01, respectively) and between the VG and the inverted vein + VASCG (-59.9 vs. -88.92, p=0.02). At week 12, this study showed a difference between the AG and the VG (-64.8 vs. -47.3, p=0.004, respectively), and also a difference between the VG and the VASCG (-47.3 vs. -57.4, p=0.02, respectively). There was no difference in the histomorphometry analysis (nerve diameter, Schwann cells counting). The gastrocnemius muscles on the intervention side were more atrophic when compared to the gastrocnemius muscles on the control side. Conclusions: Our results suggested better functional recovery in the inverted vein group when compared to control group, and inverted vein + ASC group.

A modified hydrogel production protocol to decrease cellular content

Purpose: To analyze the cytotoxicity and cell in porcine-derived decellularized skin matrix. Methods: We analyzed the effect of multiple decellularization processes by histological analysis, DNA quantification, and flow cytometry. Subsequently, we analyzed the most appropriate hydrogel concentration to minimize cytotoxicity on fibroblast culture and to maximize cell proliferation. Results: After the fourth decellularization, the DNA quantification showed the lowest DNA concentration (< 50 ng/mg). Histological analysis showed no cell components in the hydrogel. Moreover, hematoxylin and eosin showed a heterogeneous structure of collagen fibers. The best hydrogel concentration ranged from 3 to 25%, and there was no significant difference between the 24 hours and seven days. Conclusions: The process of hydrogel production was effective for removing cells and DNA elements. The best hydrogel concentration ranged from 3 to 25%.

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.

Light-emitting diode stimulates radiodermatitis recovery

Purpose To evaluate the effect of light-emitting diode (LED) in an experimental model of radiodermatitis. Methods Ten male Wistar rats weighing 200250 g were analyzed. Radiation was delivered in a single dose (20 Gy with Strontium-90 dermatological plaques), two areas per animal. After 15 days, they were divided into two groups: control group (n = 5) and LED group (n = 5), which was treated during 21 days later (LED 660 nm, 10 min in alternate days). The endpoints were radiodermatitis scale, histological analysis HE, Picrius Sirius and the gene expression of interleukin-10 (IL-10) and matrix metalloproteinase-9 (MMP-9). Results The LED group showed a higher number of dermal appendages (p = 0.04) and angiogenesis(p = 0.007), a tendency towards higher IL-10 (p = 0.06) and an increase in MMP-9 (p = 0.004) when compared to the control group. Conclusions This study suggested that the use of LED for radiodermatitis increased skin regeneration.(AU)

A non-inferiority study to compare daily fast-acting insulin versus twice a week slow-acting insulin moderate diabetes mode

Purpose Given the high prevalence of diabetes (D), several animal models have been analyzed. In the literature, most of the animal models have studied severe D. However, in clinical practice, most patients have moderate disease. Therefore, the present study aimed to describe a moderate D condition. Methods We analyzed 20 Wistar rats, age eight-weeks, weight between 200g-250g. All animals received an intravenous injection of Streptozotocin (55mg/kg weight). On the 15th day after D induction, the animals were divided into two groups: Group I animals receiving a single daily dose of fast-acting insulin (FAIG) NPH (1UI,SC) for partial glycemic control, and Group II - animals receiving slow-acting insulin (SAIG) twice a week. We measured glycemia, weight, and adverse events every week during two months. Results Of the total of animals analyzed in the study, three animals died in the FAIG and two animals died in the SAIG. Regarding the glycemic level, results were 339.5 ± 125.4mg/dL (95CI 302.3402 to 376.6842) in the FAIG, and 367.8 ± 66.1mg/dL (95IC 333.7607 to 401.8978) in the SAIG. There was no difference between groups as to weight during the study. Conclusion The use of slow-acting-insulin is not inferior to the use of fast-acting-insulin in the management of partially insulin-controlled moderate diabetes in rats.(AU)

Analysis of inflammatory and metabolic biomarkers in patients submitted to abdominoplasty after bariatric surgery

Purpose: To evaluate the serum variations of Interleukins (Il) and CPR of abdominoplasties in post-bariatric patients and, to equate the homeostasis (HOMA) from the variations of glycemia and insulin to evolute the metabolic modifications.Methods: Fourteen women were submitted to abdominoplasties with weight loss after a gastroplasty. Levels of IL4, IL6, IL10, CRP, glycemia and insulin were obtained during the pre-operative, trans-operative, 24 hours post, 7th and 14th postoperative days.Results: The IL4 was higher at 24 hours post-surgery, and after a moderate decrease, it remained high until the 14th day. The IL6 and CRP had an expressive increase during the trans-operative period. The CRP remained high, and the IL6 decreased on the 7th and 14th days. The IL10 increased during the transoperative period, and it posteriorly decreased to lower levels in comparison to the pre-operative period. The already increased glycemia during the pre-operative period was even higher during the trans-operative and then, returned to preliminary values on the 7th and 14th days after surgery. The HOMA accompanied the insulin. Conclusion: The inflammatory and glycemic serum levels decrease after abdominiplasty in obese post-bariatric patients.(AU)

Hyaluronic acid in tobacco-exposed rats. Inflammatory reaction, and duration of effect

Purpose:To evaluate the hyaluronic acid (HA) inflammatory reaction, fibroblasts, fibrosis and duration of effect in the dorsal region of tobacco-exposed rats.Methods:Ten Wistar rats were divided into two groups: tobacco-exposed-group (TEG;n=5) and air-control-group (CG;n=5). The TEG animals were tobacco-exposed twice a day, 30-minutes/session, during 60 days. After this period, all animals received 0.1 mL HA subcutaneous injection in the dorsal area. The volume of HA was measured immediately after HA injection and weekly using a hand-caliper in nine weeks. After this period, all the animals were euthanized, and a specimen of was collected to evaluate inflammatory cells, fibroblasts, and fibrosis by HE.Results:This study showed a higher inflammatory reaction in TEG than CG: inflammatory cell-count (CG: 1.07±0.9; TEG: 8.61±0.36, p<0.001); fibroblast count (CG: 2.92±0.17; TEG: 19.14±0.62, p<0.001), and fibrosis quantification (CG: 2.0; TEG: 3.75, p<0.001). The analysis of the HA volume in nine weeks in the dorsal region did not show a difference between groups (p=0.39).Conclusions:This study suggested that the HA injection in the TEG caused an increase in inflammatory cell count, fibroblast, and fibrosis quantification when compared to the CG. There was no difference in the duration of effect of HA between the groups.(AU)

A non-living, effective model for microvascular training

Purpose: To introduce a nonliving microvascular training model based on vessels diameter and feasibility. Methods: We dissected ten oxen tongues, and divided the pedicles into three-thirds: proximal, middle and distal. We measured the external vessels diameter in all regions. We performed a descriptive statistical analysis. Three students (two beginner level and one intermediate level) performed this training. We evaluated the confidence, according Likert scale. Results: We dissected all oxen tongues, each tongue showed two parallel pedicles. Each pedicle was located at 1.5 - 2.0 cm from the midline. Proximal median artery and vein diameter were 3.9 ± 0.7, and 5.04 ± 1.44mm, respectively. In the middle third, the mean artery diameter was 3.3 ± 0.4mm, and the vein diameter was 3.5 ± 0.9mm. The distal third showed a mean artery diameter of 2.0 ± 0.42mm, and a vein diameter of 2.4 ± 0.82mm. The students performed ten anastomoses. This study showed a higher confidence level (CL) (p=0.03) than the pre training CL assessment. Conclusion: This study suggested a feasible non-animal model for microsurgical training process for beginners and intermediate trainees.(AU)

Qualitative analysis of the viability of autogenous fat grafts grafted in different environments of interstitial pressure. Preliminary results and description of a new experimental model in mini-pigs

Purpose: To evaluate the feasibility of an experimental model of autologous fat graft (AFG) in different interstitial pressure (IP) environments. Methods: Three mini-pigs(Minipig-BR) with age of 8 months (weight: 25-30 kg) were used. AFG were collected from the bucal fat pad, and grafted in the intramuscular pocket (biceps femoralis muscle). IP model was based on a fusiform ressection followed by primary closure under tension. A blood pressure catheter located in the intramuscular region connected to a pressure module was applied to quantify IP. Results: The mean operative time was 236 min (210 - 272 min). All the AFG and muscular segments were removed successfully. Average interstitial pressure CP and H were 3 and 10.6 mmHg respectively. The AFG were biopsied for histopathological analysis 30 days after graft. Hematoxylin-eosin staining and immunohistochemical analyzes (TNF-alpha, CD31 and Perilipine with monoclonal antibodies) were employed. Conclusion: The data show that minipigs model could be used as a recipient site for autologous fat graft techniques and allow the development of studies to explore the AFG intake and pathophysiology response.(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)

Tibial and fibular nerves evaluation using intraoperative electromyography in rats

PURPOSE:To evaluate a new model of intraoperative electromyographic (EMG) assessment of the tibial and fibular nerves, and its respectives motor units in rats.METHODS:Eight Wistar rats underwent intraoperative EMG on both hind limbs at two different moments: week 0 and week 12. Supramaximal electrical stimulation applied on sciatic nerve, and compound muscle action potential recorded on the gastrocnemius muscle (GM) and the extensor digitorum longus muscle (EDLM) through electrodes at specifics points. Motor function assessment was performaced through Walking Track Test.RESULTS:Exposing the muscles and nerves for examination did not alter tibial (p=0.918) or fibular (p=0.877) function between the evaluation moments. Electromyography of the GM, innervated by the tibial nerve, revealed similar amplitude (p=0.069) and latency (p=0.256) at week 0 and at 12 weeks, creating a standard of normality. Meanwhile, electromyography of the EDLM, innervated by the fibular nerve, showed significant differences between the amplitudes (p=0.003) and latencies (p=0.021) at the two different moments of observation.CONCLUSION:Intraoperative electromyography determined and quantified gastrocnemius muscle motor unit integrity, innervated by tibial nerve. Although this study was not useful to, objectively, assess extensor digitorum longus muscle motor unit, innervated by fibular nerve.(AU)

Combined polyglycolic acid tube and autografting versus autografting or polyglycolic acid tube alone. A comparative study of peripheral nerve regeneration in rats

PURPOSE: To compare sciatic nerve regeneration in rats using three different techniques of repair. METHODS: Fifteen isogonics rats were divided into three groups according to the method used to repair a 5-mm long defect created in the sciatic nerve: autogenous graft (Group A), polyglycolic acid tube (PGAt) (Group B), and of the association of PGAt with the graft (Group C). Histological analysis, regenerated myelinated axon number count and functional analysis were used to compare after six weeks. RESULTS: There was no difference in fiber diameter and degree of myelinization presented by Groups A, B and C. Group B presented the lowest number of regenerated axons. The groups did not display any significant functional difference after walking track analysis (p<0.05). CONCLUSION: No differences between the three groups in terms of functional recovery, although there were histological differences among them.(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)

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)

Face transplantation in rats. Reproducibility of the experimental model in Brazil

PURPOSE: To investigate the reproducibility of the experimental model of face allotransplantation in rats in Brazil. METHODS: Eighteen rats were operated, nine-nine donors recipients. Animals underwent transplantation of the left hemiface, with periorbital and scalp. Transplants were made from donor Wistar rats to recipients Lewis rats. Flaps were based on the common carotid artery and the external jugular vein of the donor animal and the anastomosis in the recipient area was performed in common carotid artery (end-to-side) and in external jugular vein (end-to-end). RESULTS: Of the nine recipient animals operated, six survived and three progressed to death in the first days after surgery (survival rate = 67%). The mean time of the procedure was 252 minutes and the mean time of flap ischemia was 95 minutes. The five surviving animals were sacrificed at 14 days, in good general condition and without signs of tissue rejection. CONCLUSIONS: The experimental model of face allotransplantation in rats is reproducible in our midst. Duration of surgery, time of flap ischemia, animal survival rate and complications observed were similar to those described in the literature.(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)

An outcome analysis and long-term viability of cryopreserved cultured epidermal allografts: assessment of the conservation of transplantable human skin allografts

PURPOSE: To assess the viability of cultured epithelium and preserved by freezing for periods varying from one month to one year. METHODS: Samples of cultured epithelium were incubated in cryoprotectant medium (Group A), packed in aluminum envelopes and packed in polystyrene boxes. The boxes were subjected to a temperature of-70ºC. After freezing for a period of time ranging from one to 12 months, cultured epithelial samples were assessed for their viability by vital staining (Trypan blue) and metabolic analysis based on glucose consumption and lactate production. Samples of not frozen cultured epithelium (Group B) were also tested for viability and the results obtained were used as comparison parameter for the variation of viability. RESULTS: Statistical analysis between the group A and B indicate that the mean age of the donors (p=0.51) and the culture time (p=1.18) showed no statistical difference. In 30 days we obtained 37% of the original viability of cultured epithelium, 25% at six months and one year, less than 15%. This trend was confirmed statistically with a reduction of approximately 1.8% of the original viability epithelium cultured every 30 days of storage. In the analysis by lactate production, similar results were observed. In the analysis by the glucose consumption results were not significant. The viability indices show statistically significant difference between the group A and B (p<0.0001). CONCLUSIONS: Although cryopreserved cultured epithelium showed significant reduction of viability, all samples remained viable. It was also found that the viability of cryopreserved cultured epithelial decreased as a function of storage time.(AU)

Evaluation of nerve regeneration in diabetic rats

PURPOSE: To compare sciatic nerve regeneration between non-diabetic (control) and streptozotocin-induced diabetic Wistar rats. METHODS:Four subgroups were evaluated. CN: Non-diabetic rats submitted to neurorrhaphy (n=9); DN: Diabetic rats submitted to neurorrhaphy (n=9); CG: Non-diabetic rats submitted to nerve grafting (n=10); DG: Diabetic rats submitted to nerve grafting (n=9). The nerve regeneration was evaluated by walking track analysis (sciatic functional index), electrophysiological test, histomorphometric analysis and triceps surae muscle weight. RESULTS:At 60 days post-surgery, functional recovery of DN was similar to that of the non-diabetic rats (CN, CG), but DG didn't achieve the same. Evoked potential amplitudes showed no statistically significant differences among subgroups. Triceps surae muscle was heavier in CN. No statistically significant differences were observed between the control and diabetes subgroups with respect to histomorphometric analysis. CONCLUSION: After 60 days, DN had a functionally similar recovery to that of the control animals, whereas nerve grafting in diabetic rats didn't allow the same. The muscle atrophy was lower in CN. In the rest of evaluations, as electrophysiological and histomorphometric, diabetic rats were not different from control ones.(AU)

Comparative study and histomorphometric analysis of bone allografts lyophilized and sterilized by autoclaving, gamma irradiation and ethylene oxide in rats

PURPOSE: To compare three sterilization methods (autoclave, gamma irradiation and ethylene oxide) over non demineralized lyophilized bone allografts. METHODS: Bone allografts were implanted on paravertebral muscles of 21 rats. After 30 days animals were sacrificed and grafts underwent comparative analysis regarding histomorphometric and macroscopic parameters. RESULTS: Allografts that underwent the three sterilization methods presents similar weight gain, cortical thickness similar to control group, and less fibrosis than the control group. Grafts that underwent sterilization in autoclave presented less presence of multinucleated giant cells, although not statistically significant. There was also no statistically significant difference regarding mineralization on the three groups. CONCLUSION: The three sterilization methods cause similar effects on bone allografts regarding macroscopic and histomorphometric parameters.(AU)

Comparison between textured silicone implants and those bonded with expanded polytetrafluoroethylene in rats / Comparação entre implantes de silicone texturizados e esses recobertos por politetrafluoroetileno-expandido em ratos

PURPOSE: Comparison of the inflammatory reaction promoted by textured silicone implants and that caused by the implant bonded with e-ptfe. METHODS: One-hundred and fifty rats were divided into three equal groups (control, silicone, and bonded e-ptfe). These groups were subdivided into five groups, according to the second operation, i.e., 7,30,60,90 and 180 days. Histology of the peri-implant tissue was analyzed by morphometry with blood count (neutrophilos, lymphocytes, macrophages, fibroblasts and capillaries). RESULTS: Comparison of subgroups 7,30,60,90, 180 days: - neutrophils: silicone: > in subgroup 7 days; bonded e-ptfe: > in subgroups 7 and 30 days; - lymphocytes: silicone: > in subgroup 7 and 180 days; bonded e-ptfe: > in subgroup 180 days; - macrophages: silicone: > in subgroup 7 and 60 days; bonded e-ptfe: > in subgroup 7,30 and 60 days; - fibroblasts: silicone: > in subgroup 30 and 60 days;- vascular volume: silicone: in subgroup 7, 60 and 90 days; bonded e-ptfe: > in subgroup 7 days. Comparison of groups: neutrophils : 7 days: > in silicone and bonded e-ptfe; 30 days: > in bonded e-ptfe; - lymphocytes: - 7,30,90 and 180 days: in the control; macrophages: - 7,30 and 60 days: > in silicone & bonded e-ptfe; 180 days > in silicone; fibroblasts: - 7,30 and 90 days: > in silicone and bonded e-ptfe; 180 days: > in bonded e-ptfe; vascular volume 7,60,90 and 180 days: > in silicone and bonded e-ptfe; 30 days: > in bonded e-ptfe. CONCLUSIONS: The acute stage of the inflammatory response was more severe and irregular in the silicone implant; both the silicone implant and the silicone bonded with e-ptfe promoted chronic inflammatory reaction and weak foreign body inflammatory response. These reactions were greater in the silicone implant group.(AU)

OBJETIVO: Comparar a reação inflamatória provocada pelo implante de silicone texturizado, com aquela causada por este recoberto com PTFE-E. MÉTODOS: Foram utilizadas 150 ratas, divididos em três grupos igruais (controle, silicone e recoberto PTFE-E). Os grupos foram subdivididos em cinco subgrupos, ou seja, 7, 30, 60, 90 e 180 dias, de acordo com a data do segundo ato operatório. O tecido perimplante foi analisado histologicamente, por meio de técnica morfométrica, com contagem de neutrófilos, linfócitos, macrófagos, fibroblastos e capilares. RESULTADOS: Comparação dos subgrupos 7, 30, 60, 90 180 dias: - neutrófilos - silicone: > no subgrupo 7 dias; rec-ptfe: > nos subgrupos 7 e 30 dias; - linfócitos: silicone: > no subgrupo 7 e 180 dias; rec-ptfe: > no subgrupo 180 dias; - macrófagos: silicone: > no subgrupo 7 e 60 dias; rec-ptfe: > no subgrupo 7, 30 e 60 dias; - fibroblastos: silicone: > no subgrupo 30 e 60 dias; - volume vascular: silicone: > no subrupo 7, 60 e 90 dias; rec-ptfe: > no subgrupo 7 dias . Comparação dos gurpos: - neutrófilos - 7 dias: > no silicone e rec-ptfe; 30 dias: > no rec-ptfe; - linfócitos - 7, 30, 90 e 180 dias: > no controle; - macrófagos - 7, 30 e 60 dias: > no silcone e rec-ptfe; 180 dias: > no silicone; - fibroblastos - 7, 30 e 90 dias: > no silicone e rec-ptfe; 180 dias: > no rec-ptfe; - volume vascular - 7, 60, 90 e 180 dias: > no silicone e rec-ptfe; 30 dias: > no rec-ptfe. CONCLUSÕES: A fase aguda da reação inflamatória foi mais intensa e irregular no implante de silicone; tanto o implante de silicone como o de silicone recoberto por ptfe-e induziram a reação inflamatória crônica e a fraca reação inflamatória tipo corpo estranho. Estas forram maiores no implante de silicone.(AU)