Prótese intraescleral em um cão - evisceração e implantação / Intrascleral prosthesis in a dog - evisceration and implantation

Background: There is no hope of preserving vision at the terminal stage of glaucoma, and surgical treatment is indicated in thesecases. Among the various surgical techniques used, eye evisceration with implantation of an intrascleral prosthesis provide thebest cosmetic results. Even though eye evisceration with prosthesis implantation represents an excellent treatment option forterminal glaucoma, reports on the use of this technique in dogs are scarce in the current literature. The aim of this work is to reporta case of a dog with end-stage glaucoma subjected to eye evisceration surgery and implantation of an intrascleral prosthesis.Case: A 7-year-old bitch mixed breed with a history of glaucoma secondary to uveitis with no response to medical therapy wasreferred to the Ophthalmology service of the University Veterinary Hospital of Coimbra (HVUC), Portugal At the ophthalmicexamination, the glaucomatous left eye was buphthalmic, with congested episcleral blood vessels, mydriasis, and posterior luxation of the lens; there was no response to threat or obfuscation, no direct and consensual pupillary reflex, nor pupillary reflexesto chromatic light. The intraocular pressure (IOP) was 55 mmHg, and the Schirmer’s tear test (STT-1) result was 19 mm/min.Ophthalmoscopy revealed attenuated retinal blood vessels and a pale optic papilla with mild excavation. The right eye wasfunctional, with all parameters assessed on examination and by tests within the normal ranges for the species. An ultrasoundexamination of the left eye confirmed the presence of posterior luxation of the lens and buphthalmia in the absence of intraocularneoplasm. In view of the patient’s history and results of the clinical examinations, a surgical approach was indicated to treat theglaucomatous eye. The patient’s tutor requested a surgical procedure that...

Prótese intraescleral em um cão - evisceração e implantação / Intrascleral prosthesis in a dog - evisceration and implantation

Background: There is no hope of preserving vision at the terminal stage of glaucoma, and surgical treatment is indicated in thesecases. Among the various surgical techniques used, eye evisceration with implantation of an intrascleral prosthesis provide thebest cosmetic results. Even though eye evisceration with prosthesis implantation represents an excellent treatment option forterminal glaucoma, reports on the use of this technique in dogs are scarce in the current literature. The aim of this work is to reporta case of a dog with end-stage glaucoma subjected to eye evisceration surgery and implantation of an intrascleral prosthesis.Case: A 7-year-old bitch mixed breed with a history of glaucoma secondary to uveitis with no response to medical therapy wasreferred to the Ophthalmology service of the University Veterinary Hospital of Coimbra (HVUC), Portugal At the ophthalmicexamination, the glaucomatous left eye was buphthalmic, with congested episcleral blood vessels, mydriasis, and posterior luxation of the lens; there was no response to threat or obfuscation, no direct and consensual pupillary reflex, nor pupillary reflexesto chromatic light. The intraocular pressure (IOP) was 55 mmHg, and the Schirmers tear test (STT-1) result was 19 mm/min.Ophthalmoscopy revealed attenuated retinal blood vessels and a pale optic papilla with mild excavation. The right eye wasfunctional, with all parameters assessed on examination and by tests within the normal ranges for the species. An ultrasoundexamination of the left eye confirmed the presence of posterior luxation of the lens and buphthalmia in the absence of intraocularneoplasm. In view of the patients history and results of the clinical examinations, a surgical approach was indicated to treat theglaucomatous eye. The patients tutor requested a surgical procedure that...(AU)

Histological evaluation of capsules formed by texturized silicone implants with and without polyester mesh coverage (Parietex®). A study on female rats

ABSTRACT Purpose To evaluate capsules formed by microtextured silicone implants with and without Parietex® mesh coverage histologically. Methods Sixty Wistar rats were divided in two groups (meshed and unmeshed). Each group was, then, divided into two subgroups for evaluation at 30 and 90 days. Capsules were analyzed based on hematoxylin and eosin (HE) and picrosirius staining. Results The number of fibroblasts, neutrophils and macrophages was similar among all subgroups. There was a higher lymphocyte reaction in the 30-day meshed group (p = 0.003). Giant cell reaction, granulation tissue and neoangiogenesis were similar among the subgroups. Synovial metaplasia was milder at 90-day in the unmeshed (p = 0.002) and meshed group (p < 0.001). Capsular thickness was significantly greater in the meshed samples (30-day p < 0.001 and 90-day p < 0.001). There was a similar amount of collagen types I and III in both groups. Conclusions The mesh-covered implants produced capsules similar to the microtextured ones when analyzing inflammatory variables. Synovial metaplasia was milder at 90 than at 30 days, and the capsular thickness was significantly greater in the meshed group. A similar amount of collagen types I and III was observed. Due to these characteristics, the mesh coverage did not seem to significantly affect the local inflammatory activity.

Avaliação de simuladores aplicados à síntese de tecidos junto a alunos de medicina veterinária / Comparison of simulators for tissue suture training by Veterinary Medicine students

O presente estudo avaliou a efetividade de simulador de sutura de silicone frente ao modelo usual em feltro e bastidor no desenvolvimento da habilidade em síntese cirúrgica. Vinte e seis alunos de Medicina Veterinária, sem vivência cirúrgica, foram distribuídos em dois grupos: o primeiro utilizou modelo de simulador em silicone e o segundo o simulador em bastidor e feltro. Em três encontros foram abordados conceitos sobre síntese, tipos de sutura e treinamento prático. Para avaliar sua experiência e percepções, os alunos responderam a um questionário e foram avaliados pelos professores na confecção dos padrões de sutura. Na avaliação do questionário, o simulador em silicone foi superior em sete das 10 questões. Na avaliação dos docentes, não houve diferença entre os grupos. Concluímos que ambos os modelos foram efetivos no desenvolvimento da habilidade cirúrgica, porém, a aceitabilidade dos alunos foi superior no modelo inovador.

This study compared the efficiency of a novel silicone model to a traditional low-fidelity method on the acquisition of surgical synthesis skills. Twenty-six veterinary students with no prior surgical training were randomly allocated into two groups: the first used a novel silicon model and second trained on a traditional set up. During three sessions, subjects such as synthesis, suture patterns, and suture practice were discussed. In order to assess the students experiences and perceptions, a questionary was applied. Students were also evaluated by teachers who scored their suture patterns. The questionary showed that the silicone model was superior in 7 out of 10 questions. No significant differences were detected between groups on the assessment by the teachers. This study shows that either model is effective for the development of suture skills. Nonetheless, the novel silicone model tested here has better acceptability when compared with the traditional model.

Avaliação de simuladores aplicados à síntese de tecidos junto a alunos de medicina veterinária / Comparison of simulators for tissue suture training by Veterinary Medicine students

O presente estudo avaliou a efetividade de simulador de sutura de silicone frente ao modelo usual em feltro e bastidor no desenvolvimento da habilidade em síntese cirúrgica. Vinte e seis alunos de Medicina Veterinária, sem vivência cirúrgica, foram distribuídos em dois grupos: o primeiro utilizou modelo de simulador em silicone e o segundo o simulador em bastidor e feltro. Em três encontros foram abordados conceitos sobre síntese, tipos de sutura e treinamento prático. Para avaliar sua experiência e percepções, os alunos responderam a um questionário e foram avaliados pelos professores na confecção dos padrões de sutura. Na avaliação do questionário, o simulador em silicone foi superior em sete das 10 questões. Na avaliação dos docentes, não houve diferença entre os grupos. Concluímos que ambos os modelos foram efetivos no desenvolvimento da habilidade cirúrgica, porém, a aceitabilidade dos alunos foi superior no modelo inovador.(AU)

This study compared the efficiency of a novel silicone model to a traditional low-fidelity method on the acquisition of surgical synthesis skills. Twenty-six veterinary students with no prior surgical training were randomly allocated into two groups: the first used a novel silicon model and second trained on a traditional set up. During three sessions, subjects such as synthesis, suture patterns, and suture practice were discussed. In order to assess the students experiences and perceptions, a questionary was applied. Students were also evaluated by teachers who scored their suture patterns. The questionary showed that the silicone model was superior in 7 out of 10 questions. No significant differences were detected between groups on the assessment by the teachers. This study shows that either model is effective for the development of suture skills. Nonetheless, the novel silicone model tested here has better acceptability when compared with the traditional model.(AU)

The alternative model of silicone for experimental simulation of suture of living tissue in the teaching of surgical technique

Purpose: To develop a silicone alternative model of tissue suture simulation to be used in the teaching of surgical technique. Methods: Twelve alternative models of silicone for tissue suture simulation were manufactured and implemented as a tool for suture pattern training of undergraduate medical students of Universidade Federal do Amazonas. Forty-eight students participated in the research. The evaluation of the proposed model was done through a questionnaire using the Likert scale, in order to verify the student satisfaction index of the alternative resource and its performance as opposed to the model historically used in the discipline, which is to suture in cloths. Results: The alternative model showed satisfactory results, especially with respect to the structural aspect, such as, better perception of anatomical planes, handling and transport. About 89.58% of positive concordant responses demonstrating expressive approval for incorporation of a complementary form of the alternative methodological proposal of the discipline of surgical technique. Conclusions: The model developed for experimental simulation of tissue sutures has proved to be a fully feasible alternative method for the training of this surgical skill. It is a simple, reproducible and low-cost model.(AU)

Comparative study of four different types of intraperitoneal mesh prostheses in rats

Purpose: To compare four types of mesh regarding visceral adhesions, inflammatory response and incorporation. Methods: Sixty Wistar rats were divided into four groups, with different meshes implanted intraperitoneally: polytetrafluoroethylene (ePTFE group); polypropylene with polydioxanone and oxidized cellulose (PCD); polypropylene (PM) and polypropylene with silicone (PMS). The variables analyzed were: area covered by adhesions, incorporation of the mesh and inflammatory reaction (evaluated histologically and by COX2 immunochemistry). Results: The PMS group had the lowest adhesion area (63.1%) and grade 1 adhesions. The ePTFE and PM groups presented almost the total area of their surface covered by adherences (99.8% and 97.7% respectively).The group ePTFE had the highest percentage of area without incorporation (42%; p <0.001) with no difference between the other meshes. The PMS group had the best incorporation rate. And the histological analysis revealed that the inflammation scores were significantly different. Conclusions: The PM mesh had higher density of adherences, larger area of adherences, adherences to organs and percentage of incorporation. ePTFE had the higher area of adherences and lower incorporation. The PMS mesh performed best in the inflammation score, had a higher incorporation and lower area of adherences, and it was considered the best type of mesh.(AU)

Histological evaluation of capsules formed by silicon implants coated with polyurethane foam and with a textured surface in rats

PURPOSE:To assess the capsules formed by silicone implants coated with polyurethane foam and with a textured surface.METHODS:Sixty-four Wistar albinus rats were divided into two groups of 32 each using polyurethane foam and textured surface. The capsules around the implants were analyzed for 30, 50, 70 and 90 days. Were analyzed the following parameters: foreign body reaction, granulation tissue, presence of myofibroblasts, neoangiogenesis, presence of synovial metaplasia, capsular thickness, total area and collagen percentage of type I and III, in capsules formed around silicone implants in both groups.RESULTS:The foreign body reaction was only present in the four polyurethane subgroups. The formation of granulation tissue and the presence of myofibroblasts were higher in the four polyurethane subgroups. Regarding to neoangiogenesis and synovial metaplasia, there was no statistical difference between the groups. Polyurethane group presented (all subgroups) a greater capsule thickness, a smaller total area and collagen percentage of type I and a higher percentage area of type III, with statistical difference.CONCLUSION:The use of polyurethane-coated implants should be stimulated by the long-term results in a more stable capsule and a lower incidence of capsular contracture, despite developing a more intense and delayed inflammatory reaction in relation to implants with textured surface.(AU)

Effect of propranolol on capsular reaction around silicone implants in guinea pigs

PURPOSE: To evaluate the effect of propranolol on capsular architecture around silicone implants by measuring the inflammation, capsular thickness, and collagen fiber density, using a guinea pig experimental model. METHODS: Thirty six adult male guinea pigs randomly divided into two groups (n=18) were used. Each one received a silicone implant with textured-surface. The capsular tissue around implants from untreated or treated animals with the beta-adrenoceptor antagonist propranolol (10 mg/kg, dissolved in daily water) were analyzed for inflammation by histological scoring, capsular thickness by computerized histometry, and collagen fibers type I and Type III density by picrosirius polarization at different time points (7, 14 or 21 days after silicone implantation).RESULTS: Propranolol treatment reduced inflammation and impaired capsular thickness and delayed collagen maturation around the textured implant. CONCLUSION: Propranolol reduces the risk of developing capsular contracture around silicone implants with textured surface.(AU)

Effect of zafirlukast on capsular contracture around silicone implants in rats / Efeito do zafirlukast na contratura capsular ao redor de implantes de silicone em ratos

PURPOSE: To evaluate the effect of zafirlukast on capsular contracture around silicone implants by measuring the pressure within the implant, using a rat experimental model. METHODS: Forty adult female Wistar rats were used. Each one received two silicone implants, one with smooth-surface and the other with textured-surface. They were randomly divided into four groups (n=10). The rats of control group I were sacrificed after the implants. The remaining animals were subjected to a daily regimen of intra-peritoneal injection for a period of 90 days and they were distributed as follows: control group II received 0.9 percent physiological saline solution; experimental group I received zafirlukast 1.25 mg/kg; and experimental group II received zafirlukast 5 mg/kg. The measurement of intra-implant pressure of control group I was determined on the surgery day and in other groups on the ninetieth day, after being sacrificed. RESULTS: In the evaluation of textured implants there was an increase of internal pressure in the control group II, and there was no increase in the experimental groups. Compared to the controls there were not significant differences in smooth implants. CONCLUSION: Zafirlukast reduced the risk of developing capsular contracture around silicone implants with textured surface.(AU)

OBJETIVO: Avaliar o efeito do zafirlukast na contratura capsular ao redor de implantes de silicone, através da aferição da pressão intra-implante, utilizando-se um modelo experimental de ratos. MÉTODOS: Quarenta ratos fêmeas Wistar foram utilizados. Cada um recebeu dois implantes de silicone, sendo um com superfície lisa e outro texturizada. Foram divididos aleatoriamente em quatro grupos (n=10). Os ratos do grupo controle I foram sacrificados após o implante. O restante dos animais foi submetido a um regime diário de injeção intraperitoneal por um período de 90 dias e foram distribuídos: grupo controle II recebeu solução salina fisiológica 0,9 por cento, grupo experimental I recebeu zafirlukast 1,25 mg/kg, e grupo experimental II recebeu zafirlukast 5 mg/kg. O grupo controle II recebeu solução salina; grupo experimental I, 1,25 mg/kg/dia de zafirlukast; grupo experimental II, 5mg/kg/dia de zafirlukast. A aferição da pressão intra-implante do grupo controle I foi averiguada no dia do ato operatório, e nos outros grupos no nonagésimo dia, após serem sacrificados. RESULTADOS: Na avaliação dos implantes texturizados houve aumento da pressão interna no grupo controle II e, não se observou aumento nos grupos experimentais. Na comparação com os controles não foram observadas diferenças significativas nos implantes lisos. CONCLUSÃO: O Zafirlukast reduziu o risco de desenvolver contratura capsular em torno de implantes de silicone com superfície texturizada.(AU)

Histopathological reaction over prosthesis surface covered with silicone and polyurethane foam implanted in rats / Reação histopatológica sobre a superfície de próteses cobertas por espuma de silicone e poliuretano implantadas em ratos

PURPOSES: To evaluate whether polyurethane foam leads more intense foreign-body reaction than silicone foam. To compare the vascularization of the capsules surrounding the foam implants. To investigate if the capsule of polyurethane foam implanted has greater amount of collagen than that of silicone foam. METHODS: Sixty-four young male Wistar rats were allocated into two groups: polyurethane foam and silicone foam. Subcutaneous discs were implanted into the dorsum of the animals in both groups. The capsules were assessed 28 days, two months, three months and six months postoperatively. Microscopic analysis with H&E stain was performed to evaluate the acute and chronic inflammatory process, foreign-body reaction and neovascularization. The analysis with picrosirius red was performed using the ImageProPlus software, to measure the number of vessels and collagen types I and III. RESULTS: There were no statistical differences between the two groups regarding the acute and chronic inflammatory processes. All rats from the polyurethane group, in all times, exhibited moderate or intense foreign-body reaction, with statistic significant difference (p=0.046) when compared with the silicone group, in which the reaction was either mild or nonexistent at two months. Vascular proliferation was significantly different between the groups at 28 days (p=0.0002), with the polyurethane group displaying greater neovascularization with H&E stain. Similar results were obtained with picrosirius red, which revealed in the polyurethane group a much greater number of vessels than in the silicone group (p=0.001). The collagen area was larger in the polyurethane group, significantly at 28 days (p=0.001) and at two months (p=0.030). CONCLUSIONS: Polyurethane foam elicited more intense foreign-body reaction when compared with silicone foam. The number of vessels was higher in the capsules of the polyurethane foam implants 28 days after the operation. The capsule of the polyurethane foam implants showed a greater amount of collagen than that of the silicone foam implants.(AU)

OBJETIVOS: Avaliar, em relação ao uso de próteses, se a espuma de poliuretano apresenta maior reação de corpo estranho no organismo ao ser comparada com a espuma de silicone. Se há diferenças na vascularização das cápsulas formada ao redor das duas espumas implantadas. Se as cápsulas dos implantes de espuma de poliuretano apresentam quantidade maior de fibras colágenas ao serem comparadas com as da espuma de silicone. MÉTODOS: Utilizou-se 64 ratos albinos da linhagem Wistar, distribuídos em dois grupos de 34, grupo espuma de poliuretano e grupo espuma de silicone e receberam implantes discóides subcutâneos em seu dorso. Foram analisadas as cápsulas peri-implante com 28 dias, dois, três e seis meses após a introdução. A análise microscópica com H&E considerou as variáveis: inflamação aguda, inflamação crônica, reação de corpo estranho e neoformação vascular. A análise da coloração com picrosirius-red usando ImageProPlus considerou o número de vasos e colágeno tipo I e tipo III. RESULTADOS: Em relação à inflamação aguda e crônica, não foram encontradas diferenças estatísticas nos dois grupos. Todos os animais do grupo poliuretano, em todos os momentos, apresentaram reação de corpo estranho moderada ou intensa e foi encontrada diferença estatística significativa (p=0,046) ao serem comparados com o grupo silicone, cuja reação era ausente ou discreta aos dois meses. A neoformação vascular apresentou diferenças significativas nos dois grupos, aos 28 dias (p=0,0002); o grupo poliuretano com H&E apresentava quantidade maior de vasos neoformados e o mesmo ocorrendo com o picrosirius, cujo número de vasos era maior que no grupo silicone (p=0,001). A área de colágeno em todos os momentos foi maior no grupo poliuretano, sendo significativa com 28 dias (p=0,001) e com dois meses (p=0,030). CONCLUSÕES: A espuma de poliuretano apresentou maior reação de corpo estranho no organismo do que a espuma de silicone. A quantidade de vasos foi maior na cápsula da espuma de poliuretano com 28 dias após o implante. Aos 28 dias as cápsulas dos implantes de espuma de poliuretano apresentaram quantidade significativamente maior de colágeno do que as de espuma de silicone.(AU)

Anatomical and functional evaluation of tympanoplasty using a transitory natural latex biomembrane implant from the rubber tree Hevea brasiliensis / Avaliação anatômica e funcional da timpanoplastia com a utilização de implante transitório de biomembrana natural de látex proveniente da seringueira Hevea brasiliensis

PURPOSE: To compare the role of transitory latex and sylastic® implants in tympanoplasty on the closure of tympanic perforations. METHODS: A randomized double-blind prospective study was conducted on 107 patients with chronic otitis media submitted to underlay tympanoplasty and divided at random into three groups: control with no transitory implant, latex membrane group, and sylastic® membrane group. RESULTS: Greater graft vascularization occurred in the latex membrane group (p<0.05). Good biocompatibility was obtained with the use of the latex and silicone implants, with no effect on the occurrence of infection, otorrhea or otorragy. CONCLUSION: The use of a transitory latex implant induced greater graft vascularization, with a biocompatible interaction with the tissue of the human tympanic membrane.(AU)

OBJETIVO: Investigar os efeitos da biomembrana de látex e silicone no fechamento de perfurações timpânicas. METODOS: Foram estudados 107 pacientes com otite média cronica simples submetidos à cirurgia de timpanoplastia. Os pacientes foram classificados aleatoriamente, por sorteio, em três grupos. Até o final da cirurgia, os cirurgiões não tomavam conhecimento se seria ou não utilizado qualquer material externamente ao enxerto de fáscia temporal. Neste momento, o paciente que fora previamente classificado por uma ordem aleatória de entrada como participante do estudo foi identificado como participante do grupo 1, 2 ou 3, sendo, respectivamente, ausência de implante transitório no primeiro, membrana de látex no segundo e membrana de sylastic® no terceiro grupo. RESULTADOS: Houve uma maior vascularização do enxerto no grupo em que foi utilizado implante transitório de membrana de látex (p<0,05). Obteve-se boa biocompatibilidade com uso de implantes de látex e silicone sem afetar as taxas de ocorrência de infecção, otorreia ou otorragia. A porcentagem de cicatrização da membrana timpânica foi equivalente nos três grupos, assim como a melhora auditiva (p<0,01). CONCLUSÃO: O uso do implante transitório de látex provocou um maior processo de vascularização do enxerto, com interação satisfatória com os tecidos da membrana timpânica humana.(AU)

Facoemulsificação em cães, com e sem implante de lente intra-ocular em piggyback: estudo clínico da inflamação pós-operatória / Phacoemulsification in dogs with and without intraocular lens implantation in piggyback: Clinical study of postoperative inflammation

A uveíte peri e pós-operatória é o maior problema da cirurgia para extração de catarata no cão, sendo considerada o fator mais importante para o sucesso cirúrgico, imediato e tardio. Diversos protocolos pré e pós-operatórios utilizando agentes anti-inflamatórios esteroidais e não-esteroidais têm sido empregados na tentativa de controle da uveíte cirurgicamente induzida. O objetivo do presente estudo foi avaliar a reação inflamatória pós-operatória, clinicamente e por meio da pressão intraocular (PIO), após a cirurgia de facoemulsificação para extração de catarata em cães, com e sem implante de lente intraocular (LIO) em piggyback. Empregaram-se, 25 cães portadores de catarata, subdivididos em dois grupos: G1 (com implante de LIO), G2 (sem implante de LIO). A técnica cirúrgica adotada foi a facoemulsificação bimanual unilateral. Avaliações clínicas e mensurações da PIO foram aferidas antes do procedimento cirúrgico (0) e nos tempos 3, 7, 14, 21, 28 e 60 dias após o ato cirúrgico. Cães do grupo G1 apresentaram sinais clínicos de uveíte visivelmente mais intensos, relativamente aos do G2. Entretanto, a PIO não demonstrou diferença significativa entre os dois grupos analisados, nem entre os olhos operados e os contralaterais. A utilização de duas LIOs humanas em piggyback no cão é exequível, porém suscita mais inflamação e complicações no pós-operatório.(AU)

Perioperative and postoperative uveitis is the main problem in cataract surgery in dogs, affecting short-term and long-term postoperative success. Numerous therapeutic methods involving both steroidal and non-steroidal anti-inflammatory agents have been used to reduce surgically-induced uveitis. The purpose of this study was to investigate the postoperative inflammatory reaction and intraocular pressure after phacoemulsification surgery for cataract extraction with and without intraocular piggyback lens (IOL) implantation in dogs. A total of 25 dogs were divided into two groups: Group 1 (with IOL implantation) and Group 2 (without IOL implantation). The performed surgical technique consisted of unilateral bimanual phaco-emulsification. Clinical assessment and intraocular pressure were measured before surgery (0) and at 3, 7, 14, 21, 28, 60 days after the surgery. Clinical assessment revealed inflammatory reaction more severe in dogs of G1 when compared to G2. Intraocular pressure did not differ significantly either between G1 and G2 or operated and non-operated eyes. Intraocular lens (IOL) implantation using piggyback technique with human IOL is a possible method to be performed in canine ophthalmology. However, nursing care is necessary as the the procedure induces inflammation and complications in the postoperative period.(AU)

Evaluation of low intensity laser's action on silicone mammary implant pseudocapsules in rats / Avaliação do laser de baixa intensidade sobre a pseudocápsula de implantes mamários de silicone em ratos

PURPOSE: To evaluate the effect of low intensity laser on the pseudocapsula contraction that occurs around silicone implants. METHODS: 60 male rats divided in two experimental groups received a silicone implant in the subcutaneous of the dorsal region. Group I: animals received implants in the subcutaneous dorsal region and did not receive any treatment; Group II: animals received seven irradiation sessions with low intensity laser after they had received subcutaneous implants. Thirty, 60 and 180 days after the surgery, tonometric evaluation of the implants was conducted. After that, the animals were sacrificed, study material was removed and prepared for histological examination. The thickness of the pseudocapsule and the inflammatory reaction were morphometrically quantified. Data obtained were statistically analyzed using the Variance method, and Tukey's Test(P<0.0 5). RESULTS: Group II animals had significant lower pressure. The histological study did not show a significant difference between the groups, but only a higher number of swollen vessels in Group II. The thickness of pseudocapsule around Group II's implants lower than in Group I. CONCLUSION: The low intensity laser modify tissue's reparation process around the implants suggesting it may be useful to model contractures that are formed around silicone implants.(AU)

OBJETIVO: Avaliar o efeito do laser de baixa intensidade sobre a contração da pseudocápsula que ocorre ao redor de implantes de silicone. MÉTODOS: 60 ratos machos divididos em dois grupos receberam implante de silicone. Grupo I: implante no subcutâneo da região dorsal, sem tratamento após a cirurgia; Grupo II: animais receberam sete sessões de irradiação com laser de baixa intensidade após o implante. Trinta, 60 e 180 dias após a cirurgia, foi feita a tonometria dos implantes, Em seguida, os animais foram sacrificados, removendo-se o material de estudo que foi preparado para exame histológico, avaliando-se morfometricamente a espessura da pseudocápsula e a reação inflamatória. A análise estatistica pela técnica da Análise de Variância e Teste de Tukey (P<0.0 5). RESULTADOS: Pressões significativamente menores foram encontradas nos animais do grupo Grupo II. O estudo histológico não mostrou diferença significativa entre os grupos, destacando-se apenas maior quantidade de vasos intumescidos no Grupo II. A espessura da pseudocápsula foi menor no Grupo II. CONCLUSÃO: O laser de baixa intensidade altera o processo de reparação tecidual ao redor dos implantes, sugerindo que o mesmo possa ser útil para a modelação das contraturas que se estabelecem ao redor dos implantes de silicone.(AU)

Healing reaction to mammary prostheses covered by textured silicone and silicone foam in rats / Reação capsular aos revestimentos de próteses mamárias de silicone texturizado e espuma de silicone em ratos

PURPOSE: To compare the capsular reaction to two different coverings of silicone prosthesis through the biophysical characteristic of adherence and microscopical aspects of the inflammatory reaction and collagen formation. METHODS: Thirty two Wistar rats were used. In the dorsum of each animal a silicone elastomer with a smooth superficies and another coated with texturized silicone (Mentor) was implanted. Another one, with the same smooth superficies and other coated with silicone foam (Lifesil), making up in each side, of the dorsum, the texturized and silicone foam group respectively. The animals were split into four groups to be evaluated at 7, 14, 30 and 60 days. On the evaluation dates the implant adherence was verified witch a tensiometer and the values in kgf were obtained. The material was sent to histological analysis with hematoxilin-eosin and picrosirius colorations, to evaluate the inflammatory reaction and collagen synthesis, respectively. The obtained data were submitted to statistical treatment. RESULTS: There was more adherence of the tissue to the silicone foam (P<0,001). The inflammatory reaction was more intense in the same group, but without statistical significance. The number of giant cells and granulomas were more frequent in the silicone foam group. There was statistical significance at the 60 days for granulomas (P<0,028) and for all subgroups about number of giant cells (P< 0,012 to P<0,036). The thickness of the capsule in the silicone foam group was bigger, with statistical significance at seven days (P<0,028) and 60 days (P<0,012). The collagen deposition showed no difference in statistical analysis. CONCLUSION: The capsular reaction to the silicone foam showed stronger adherence, bigger thickness and had more number of granulomas and giant cells. No difference was observed in the intensity of inflammatory reaction in relation to type I and III collagen, when compared to the texturized cover.(AU)

OBJETIVO: Comparar a reação capsular de dois revestimentos de próteses de silicone através da característica biofísica de aderência e dos aspectos microscópicos de reação inflamatória e formação de colágeno. MÉTODOS: Implantaram-se no dorso de 32 ratos duas membranas de silicone ambas possuindo uma superfície lisa e outra diferindo em sua estrutura. Estes revestimentos foram de espuma de silicone (LifeSil) ou silicone texturizado (Mentor). Os dois grupos foram divididos em quatro sub-grupos conforme o tempo de pós-operatório avaliado: 7, 14, 30 e 60 dias. Obteve-se material para análise biofísica de aderência, a qual foi realizada com tensiômetro para obtenção de valores em kgf. O estudo microscópico da reação inflamatória e síntese de colágeno foi realizado com colorações de hematoxilina-eosina e picrosirius. Os dados foram submetidos a testes para avaliação da significância estatística. RESULTADOS: Houve maior aderência do revestimento de espuma de silicone ao tecido capsular, sendo este valor estatisticamente significativo (P<0,001). Quanto à reação inflamatória observou-se maior intensidade também neste grupo, porém sem significância estatística. Na contagem de células gigantes e granulomas os valores foram maiores para o grupo espuma de silicone com significância estatística no sub-grupo 60 dias (P<0,028) para número de granulomas; e em todos os sub-grupos (variando de P<0,012 a P<0,036) para o número de células gigantes. A reação capsular à espuma de silicone foi mais espessa, com significância estatística nos sub-grupos sete dias (P<0,028) e 60 dias (P<0,012). No estudo da síntese de colágeno, as diferenças não foram significantes estatisticamente. CONCLUSÃO: A reação capsular ao revestimento de espuma de silicone apresentou características de ter maior aderência ao tecido peri-implante, ser mais espesso, possuir maior número de granulomas e células gigantes de corpo estranho. Não demonstrou diferença quanto à intensidade da reação ...(AU)

Evaluation of porous vitreous carbon or silicon implants by radiology in rat's skull / Avaliação radiológica de implantes de carbono vítreo poroso ou silicone em crânio de ratos

PURPOSE: Evaluate by CT the use of porous vitreous carbon (PVC) and silicon (S) implants as the replacement bone in the craniofacial skeleton of rats. METHODS: 40 rats divided in: Group A (n=20) PVC submitted to the implant of a fragment in skull. After the euthanasia, the animals were divided into two subgroups: A I: 10 animals, studied in the 7th postoperative day (P.O) and AII: 10 animals, studied in the 28th P.O. In group B, S, 20 rats were submitted to S implant in the skull. All other steps were identical to group A, with designation of subgroups BI and BII. CT with beams in axial cuts of 1 mm thickness to obtain 3-D information It was used Hounsfield scale for evaluate the radio density of the implant. They were used non parametric tests to analyze the results. RESULTS: The 7th PO boss remained in the two groups, but for 28th PO, observed reduction in the volume of the implant in Group A, not observed in group B. CT studies noticed different radio densities around all of S prostheses (pseudo-capsule), that don't appeared in CPV implants. The S has remained unchanged in the CT, but the CPV has had a modification in its radio density (p<0,05), in all implants. CONCLUSION: In CT evaluation the implants of CPV have greater deformation that the S, which makes them not suitable for replacement of membranous bone in the rat skull.(AU)

OBJETIVO: Realizar avaliação através de tomografia computadorizada (TC) de implantes de carbono vítreo poroso (CVP) e silicone (S) para sua utilização na substituição óssea no esqueleto craniofacial de ratos. MÉTODOS: Foram utilizados 40 ratos Wistar divididos em: Grupo A (n=20), implantes subperiostais de CVP no crânio. Após o momento da eutanásia os animais foram divididos em dois subgrupos: A I: 10 animais, estudados no 7(0) dia pós-operatório (PO) e AII: 10 animais, estudados no 28(0) PO. No grupo B (n=20), os ratos foram submetidos ao implante de silicone no crânio. Todas outras etapas foram idênticas ao grupo A, com a designação de subgrupos BI e BII. Foi realizada tomografia computadorizada com cortes axiais de 1 mm de espessura para obtenção de imagens tridimensionais. A escala de Hounsfield foi utilizada para avaliação da radiodensidade dos implantes. Testes estatísticos não paramétricos foram utilizados para analisar os resultados. RESULTADOS: O volume do implante foi mantido ao 7(0) PO nos dois grupos, mas ao 28(0) PO, ocorreu uma redução no volume do implante no grupo A, não observada no grupo B. Os estudos tomográficos demonstraram a presença de uma pseudo-cápsula ao redor dos implantes no grupo B, não observada nos implantes de CVP. Os implantes de silicone permaneceram inalterados na TC, mas os de CVP apresentaram modificação na sua radiodensidade e deformação (p<0,05). CONCLUSÃO: Na avaliação, através de TC, os implantes de CPV apresentam maior deformação que os de S, o que os torna inadequados para substituição do osso membranoso no crânio de ratos.(AU)

Fibrosis in tubularized skin flaps in rats, using silicon catheters with two different degrees of flexibility: experimental model / Fibrose em retalhos tubulizados de pele de ratos usando cateteres de diferentes flexibilidades como molde: modelo experimental

PURPOSE: Microscopically evaluate the intensity of fibrosis in tubularized skin flaps on the back of Wistar rats, using silicon molds with different degrees of flexibility. METHODS: Twenty rats were submitted to three tubularized skin flaps on their backs. In two tubular flaps, we placed, as a mold, silicon catheters with different degrees of flexibility and removed them on the seventh day after the surgery. They were divided into two groups and euthanized, on the seventh and twenty-first days respectively after the surgery for the collection of the pieces, coloration with Masson tricromic, quantification of the area of each sample and comparison among the groups. RESULTS: Fibrosis was less intense on the tubular flaps where a catheter was not used as a mold. No significant difference was verified among the pieces with the silicon catheters, but there was a tendency of less fibrosis on the tubules with the most flexible catheter. CONCLUSION: There was no significant difference among the two catheter types. Fibrosis was less intense in the flaps where the mold was not used.(AU)

OBJETIVO: Avaliar microscopicamente a intensidade da fibrose em retalhos tubulares de pele do dorso de ratos Wistar em uso de moldes de silicone de diferentes flexibilidades. MÉTODOS: Vinte animais foram submetidos à confecção de três retalhos tubulizados de pele na região dorsal. Em dois túbulos foram colocados, como molde, cateteres de silicone com flexibilidades diferentes e retirados no sétimo dia após a cirurgia. Foram divididos em dois grupos e sacrificados, respectivamente, no sétimo e vigésimo primeiro dia após a cirurgia para a coleta das peças, coloração pelo tricrômico de Masson, quantificação da área de cada amostra e comparação entre os grupos. RESULTADOS: A fibrose foi menos intensa nos retalhos tubulares em que não se usou cateter como molde. Não se verificou diferença significativa entre os retalhos com os cateteres de silicone, mas sim, tendência de menos fibrose nos túbulos com cateter mais flexível. CONCLUSÃO: Não houve diferença significativa entre os dois tipos de cateter. A fibrose foi menos intensa nos retalhos onde não se utilizou molde.(AU)