Acellular dermal matrix as a barrier in guided bone regeneration: a clinical, radiographic and histomorphometric study in dogs

Objectives The purpose of this study was to evaluate the effectiveness of the acellular dermal matrix (ADM) as a membrane for guided bone regeneration (GBR), in comparison with a bioabsorbable membrane. Material and methods In seven dogs, the mandibular pre-molars were extracted. After 8 weeks, one bone defect was surgically created bilaterally and the GBR was performed. Each side was randomly assigned to the control group (CG: bioabsorbable membrane made of glycolide and lactide copolymer) or the test group (TG: ADM as a membrane). Immediately following GBR, standardized digital X-ray radiographs were taken, and were repeated at 8 and 16 weeks post-operatively. Before the GBR and euthanasia, clinical measurements of the width and thickness of the keratinized tissue (WKT and TKT, respectively) were performed. One animal was excluded from the study due to complications in the TG during wound healing; therefore, six dogs remained in the sample. The dogs were sacrificed 16 weeks following GBR, and a histomorphometric analysis was performed. Area measurements of new tissue and new bone, and linear measurements of bone height were performed. Results Post-operative healing of the CG was uneventful. In the TG membrane was exposed in two animals, and one of them was excluded from the sample. There were no statistically significant differences between the groups for any histomorphometric measurement. Clinically, both groups showed an increase in the TKT and a reduction in the WKT. Radiographically, an image suggestive of new bone formation could be observed in both groups at 8 and 16 weeks following GBR. Conclusion ADM acted as a barrier in GBR, with clinical, radiographic and histomorphometric results similar to those obtained with the bioabsorbable membrane. To cite this article:Borges GJ, Novaes AB Jr, de Moraes Grisi MF, Palioto DB, Taba M Jr, de Souza SLS. Acellular dermal matrix as a barrier in guided bone regeneration: a clinical, radiographic and histomorphometric study in dogs.Clin. Oral Impl. Res. 20, 2009; 1105-1115.

A retrospective study of zygomatico-orbital complex and/or zygomatic arch fractures over a 71-month period

Background/Aim: The aim of this retrospective study was to evaluate the epidemiology, treatment, and complications of zygomatico-orbital complex (ZOC) and/or zygomatic arch (ZA) fractures either associated with other facial fractures or not over a 71-month period. Material and methods: This survey was performed in three hospitals of Ribeirao Preto in Sao Paulo, Brazil, from August 2002 to July 2008. The records of 1575 patients with facial trauma were reviewed. There were 140 cases of ZOC and ZA fractures either associated with other facial fractures or not. Data regarding gender, age, race, addictions, day of trauma, etiology, signs and symptoms, oral hygiene condition, day of initial evaluation, hospital admission, day of surgery, surgery approach, pattern of fractures, treatment performed, post-operative antibiotic therapy, day of hospital discharge, and post-operative complications were collected. The data were subjected to descriptive statistical analyses. Results: The most frequent fractures affected Caucasian men and occurred during the fourth decade of life. The most frequent etiology was traffic accident, and symptoms and signs included pain and edema. Type I fractures were the main injury observed, and the treatment of choice was always rigid internal fixation. Post-operative antibiotic therapy was solely employed when there was an indication. Complications were observed in 13.1% of the cases. Conclusions: The treatment protocol yielded suitable post-operative results and also showed success rates comparable to published data around the world.

Influence of Post and Resin Cement on Stress Distribution of Maxillary Central Incisors Restored with Direct Resin Composite

The current study evaluated the influence of two endodontic post systems and the elastic modulus and film thickness of resin cement on stress distribution in a maxillary central incisor (MCI) restored with direct resin composite using finite element analysis (FEA). A three-dimensional model of an MCI with a coronary fracture and supporting structures was performed. A static chewing pressure of 2.16 N/mm(2) was applied to two areas on the palatal surface of the composite restoration. Zirconia ceramic (ZC) and glass fiber (GF) posts were considered. The stress distribution was analyzed in the post, dentin and cement layer when ZC and GF posts were fixed to the root canals using resin cements of different elastic moduli (7.0 and 18.6 GPa) and different layer thicknesses (70 and 200 mu m). The different post materials presented a significant influence on stress distribution with lesser stress concentration when using the GF post. The higher elastic modulus cement created higher stress levels within itself. The cement thicknesses did not present significant changes.

Adhesion to Er : YAG laser-prepared dentin after long-term water storage and thermocycling

This in vitro study evaluated the microtensile bond strength of a resin composite to Er:YAG-prepared dentin after long-term storage and thermocycling. Eighty bovine incisors were selected and their roots removed. The crowns were ground to expose superficial dentin. The samples were randomly divided according to cavity preparation method (I-Er:YAG laser and II-carbide bur). Subsequently, an etch & rinse adhesive system was applied and the samples were restored with a resin composite. The samples were subdivided according to time of water storage (WS)/number of thermocycles (TC) performed: A) 24 hours WS/no TC; B) 7 days WS/500 TC; C) 1 month WS/2,000 TC; D) 6 months WS/12,000 TC. The teeth were sectioned in sticks with a cross-sectional area of 1.0-mm(2), which were loaded in tension in a universal testing machine. The data were subjected to two-way ANOVA, Scheffe and Fisher`s tests at a 5% level. In general, the bur-prepared group displayed higher microtensile bond strength values than the laser-treated group. Based on one-month water storage and 2,000 thermocycles, the performance of the tested adhesive system to Er:YAG-laser irradiated dentin was negatively affected (Group IC), while adhesion of the bur-prepared group decreased only within six months of water storage combined with 12,000 thermocycles (Group IID). It may be concluded that adhesion to the Er:YAG laser cavity preparation was more affected by the methods used for simulating degradation of the adhesive interface.

Analyses of cataract surgery performed by the Unified Health System in Brazil, 2006-2007

Objective. Estimate cataract surgical rates (CSR) for Brazil and each federal unit in 2006 and 2007 based on the number of surgeries performed by the Unified Health System to help plan a comprehensive ophthalmology network in order to eliminate cataract blindness in compliance with the target set by the World Health Organization (WHO) of 3 000 cataract surgeries per million inhabitants per year. Methods. This descriptive study calculates CSR by using the number of cataract surgeries carried out by the Brazilian Unified Health System for each federal unit and estimates the need for cataract surgery in Brazil for 2006-2007, with official population data provided by the Brazilian Institute of Geography and Statistics. The number of cataract surgeries was compared with the WHO target. Results. To reach the WHO goal for eliminating age-related cataract blindness in Brazil, 560 312 cataract surgeries in 2006 and 568 006 surgeries in 2007 needed to be done. In 2006, 179 121 cataract surgeries were done by the Unified Health System, corresponding to a CSR of 959 per million population; in 2007, 223 317 were performed, with a CSR of 1 179. With the Brazilian Council of Ophthalmology estimation of 165 000 surgeries each year by the non-public services, the CSR for Brazil would be 1 842 for 2006 and 2 051 for 2007. The proportions needed to achieve the proposed target were 38.6% in 2006 and 31.6% in 2007. Conclusions. Human resources, technical expertise, and equipment are crucial to reach the WHO goal. Brazil has enough ophthalmologists but needs improved planning and infrastructure in order to eliminate the problem, aspects that require greater financial investment and stronger political commitment.

Outcome Analysis of Immediate and Delayed Conservative Breast Surgery Reconstruction With Mastopexy and Reduction Mammaplasty Techniques

Background: Bilateral mammaplasty or mastopexy is frequently used for oncoplastic objectives. However, little information has been available regarding outcome following immediate and delayed reconstruction. Method: Patients were divided into Group I (immediate reconstruction) and Group II (delayed reconstruction). Retrospective review was performed to compare complications, length of hospital stay, revision surgeries, and satisfaction. The associations between the complications with potential risk factors (timing, age, body mass index, smoking, and comorbid medical conditions) were analyzed. Results: There were a total of 144 patients with a mean follow-up of 47 months. Of the 106 patients in Group I, complications occurred in 24 (22.6%), skin necrosis was observed in 7.5%, fat necrosis in 5.6%, and 6.6% patients developed local recurrence. Mean period of hospitalization was 1.89 days. Of the 38 patients of the Group II, complications occurred in 12 (31.5%), skin necrosis was observed in 7 (18.4%), fat necrosis in 4 (10.5%), and 5.2% patients developed local recurrence. Mean period of hospitalization was 1.35 days. Increased length of hospital stay greater than 1 day (P < 0.001) and the number of revision surgeries (P = 0.043) were associated with the timing of the reconstruction. In univariate analysis, no difference between groups was found with respect to complication incidence (P = 0.275); however, after adjusting for other risk factors, the probability of complications tend to be higher for Group II (OR = 2.65; 95% confidence interval - 1.01-7.00; P = 0.049). Conclusions: On the basis of the results of our study, the probability of complications tends to be higher for delayed reconstructions, and it is demonstrated that obesity and smoking are risk factors for complications. Ultimately, these data may facilitate the provision of individualized risk information for shared medical decision-making.

Immediate reconstruction following breast-conserving surgery: Management of the positive surgical margins and influence on secondary reconstruction

The efficacy of breast-conserving Surgery for the local control of early breast cancer has been repeatedly evidenced. Although immediate reconstruction following breast-conserving Surgery has been described, little information is available regarding surgical management in reoperative settings due to positive margins. We studied the influence of intraoperatively assessed and postoperatively controlled Surgical margin status on the type of breast-conserving Surgery and report our results regarding complications in a reoperative breast reconstruction scenario. All patients were seen by a multidisciplinary team who recommended breast-conserving surgery. According to the breast volume, ptosis and tumor size/location, the patients were also evaluated by a plastic Surgeon, who recommended reconstruction with the appropriate technique. Intraoperative assessment Of Surgical margins was determined by histological examination of frozen sections. The mean follow-up time was 48 months. Two hundred and eighteen patients (88.5%) underwent breast-conserving Surgery and immediate reconstruction. Twelve (5.5%) patients had a positive tumor margin after review of the permanent section. All patients underwent re-exploration. In 1.3%, a second reconstructive technique was indicated and in 2.2% a skin-sparing mastectomy with total reconstruction was performed. Our findings support the important role of the intraoperative assessment of surgical margins and its interference in the selection of reconstruction techniques and negative margins: however, it will not guarantee complete excision of the tumor. Success depends on coordinated planning with the oncologic Surgeon and careful intraoperative management, (C) 2008 Elsevier Ltd. All rights reserved.

Optimizing the nipple-areola sparing mastectomy with double concentric periareolar incision and biodimensional expander-implant reconstruction: Aesthetic and technical refinements

Although the biodimensional anatomical expander-implant system (BEIS) is a reliable technique, little information has been available regarding outcome following nipple-areola sparing mastectomy (NSM). To perform the resection of glandular tissue, while improving the surgical access and maintaining the nipple-areola vascularization we have developed a new approach for NSM based on the double concentric periareolar incision (DCPI). The purpose of this study is to analyze the feasibility, surgical planning and its outcome following NSM. 18 patients underwent NSM reconstructions. Mean time of follow-up was 29 months. The technique was indicated in patients with small/moderate volume breasts. Flap complications were evaluated and information on aesthetic results and patient satisfaction were collected. 83.3% had tumors measuring 2 cm or less (T1) and 72.1% were stage 0 and 1. All patients presented peripherally tumors located (at least 5 cm from the nipple). Skin complications occurred in 11.1%. One patient (5.5%) presented small skin necrosis and a wound dehiscence was observed in one patient (5.5%). The aesthetic result was good/very good in 94.4 percent and the majority of patients were very satisfied/satisfied. No local recurrences were observed. All complications except one were treated by a conservative approach. DCPI-BEIS is a simple and reliable technique for NSM reconstruction. The success depends on patient selection, coordinated planning with the oncologic surgeon and careful intra-operative and post-operative management. (C) 2009 Elsevier Ltd. All rights reserved.

Modified abbreviated transcavernous approach to basilar artery aneurysms-Case report

Background: Endovascular procedures and direct surgical clipping, are the main therapeutic modalities for managing of BAAs. Furthermore, giant or wide-necked aneurysms and those that involve the PCA or perforators at its neck usually are not embolized. Case Description: A 55-year-old man presented to the emergency room complaining Of Sudden and intense headache. Neurological examination evidenced meningismus. Computed tomography disclosed a subarachnoid hemorrhage (Fisher grade III). Arteriograms revealed BAA, whose neck was partially obseured by the PCP. A standard pterional craniotomy was performed, followed. by extensive drilling of the greater sphenoid wing. The neck was partially hidden by the PCP, and no proximal control was obtained without drilling the PCP and opening the CS (modified TcA). Drilling of the PCP was begun by cutting the overlying dura and extended caudally as much as possible. Next. opening, of the roof of the CS was performed by incising the dura in the oculomotor trigone medical and parallel 10 the oculomotor nerve and lateral to ICA: the incision progressed posteriorly toward the dorsum sellae. Further resection of the dorsum sellac and clivus was carried out. After performing these steps, proximal control was obtained, aneurysm was deflated, perforators were saved. and aneurysm was clipped. Conclusions: This study has demonstrated the clinical Usefulness of and abbreviated form of the TcA, which led the ""modified TcA."" in approaching complex low-lying, BAA. It provides additional surgical room by removing the PCP and partially, opening the CS, which permits further bone removal and improves exposure. (C) 2009 Elsevier Inc. All rights reserved.

Contribuição ao estudo das hepatectomias parciais com oclusão do fluxo sanguíneo aferente

O tratamento cirúrgico dos tumores hepáticos tem sido um grande desafio na história evolutiva da cirurgia. No passado, as altas taxas de morbidade e mortalidade limitavam sua aplicação como opção terapêutica. O refinamento da técnica de ressecção hepática está associado a menores índices de mortalidade e morbidade peri-operatória e, embora, a mortalidade tenha sido reduzida a menos de 10% nos serviços especializados, a morbidade ainda é bastante significativa, sendo que a hemorragia grave e a embolia aérea permanecem como complicações graves das hepatectomias. O controle da perda sanguínea é o objetivo primordial durante este tipo de cirurgia. As técnicas descritas, com a finalidade de conter a hemorragia transoperatória, são aquelas associadas à redução do fluxo sanguíneo ao fígado, seja através da oclusão vascular aferente ou manobra de Pringle por clampeamento do pedículo hepático, seja por exclusão vascular total do órgão. Hepatectomias parciais podem ser realizadas com pequeno sangramento e, mesmo quando associadas a períodos prolongados de isquemia tecidual, não foram identificadas lesões parenquimatosas ou falência hepática persistente. A redução na necessidade de reposição de sangue, no período peri-operatório, está associada a menor morbidade e à diminuição significativa na incidência de sepse abdominal. O objetivo deste estudo foi o de avaliar uma série de hepatectomias parciais com oclusão do fluxo sanguíneo aferente, em pacientes portadores de patologias benignas e neoplasias malignas. Foram analisadas 60 hepatectomias em 59 pacientes com oclusão do fluxo sanguíneo aferente quanto a possíveis fatores de risco para morbidade e mortalidade, bem como a relação entre o tempo de isquemia hepática e a variação das transaminases, tempo de protrombina e bilirrubinas, e destes, com a evolução pós-operatória. A prevalência de complicações pós-operatórias foi de 43,3% e a mortalidade de 6,7%. O fator de risco significativo para mortalidade foi tempo cirúrgico mais prolongado, quando comparado com os pacientes que não foram a óbito. Para a morbidade pós-operatória, foram identificados como fatores de risco a idade acima de 60 anos, cirurgia por neoplasia maligna, parênquima hepático anormal, ou seja, presença de cirrose, esteatose ou colestase, perda sanguínea necessitando reposição de mais de uma unidade de sangue e outros procedimentos cirúrgicos concomitantes. Na análise multivariada por regressão logística, estes fatores de risco foram reduzidos, apenas, para presença de cirrose, esteatose ou colestase. O tempo de isquemia não apresentou relação com a morbi-mortalidade pós-operatória. A variação das transaminases foram mais acentuadas nos casos com maior tempo de isquemia, porém, retornaram aos níveis pré-operatórios em, aproximadamente, uma semana. Não houve variação de tempo de protrombina e bilirrubinas quanto ao tempo de isquemia. A variação de AST e ALT não foram diferentes entre os pacientes com e sem morbidade pós-operatória.

Ativação linfocitária durante a cirurgia de revascularização miocárdica : papel da circulação extracorpórea

Introdução: Sabe-se que a cirurgia de revascularização miocárdica está associada com alteração dos mediadores inflamatórios e da função imunitária, com ativação precoce dos linfócitos que poderia ser responsável pela linfopenia e diminuição da atividade dos linfócitos no pós-operatório. A elevação enzimática está diminuída na cirurgia sem circulação extracorpórea mas este achado não está associado a melhor evolução clínica. Nesta tese, testamos a hipótese de que a cirurgia de revascularização miocárdica realizada sem circulação extracorpórea pode levar a uma ativação linfocitária de menor intensidade do que a cirurgia com circulação extracorpórea. Métodos: A resposta da ativação linfocitária foi estudada durante o período trans e pósoperatório em 28 pacientes randomizados para cirurgia de coronária sem circulação extracorpórea (n=13) ou cirurgia convencional com circulação extracorpórea (n=15), utilizando citometria de fluxo para determinar a expressão de CD25, CD26, CD69 e DR em linfócitos T (CD3+) e B (CD19+), em sangue periférico. No mesmo período foram realizadas dosagens de troponina I por quimioluminescência e realizado ecocardiograma uni-bidimensional antes e após a cirurgia. Resultados: Não houve diferença estatisticamente significativa para nenhum dos marcadores de ativação linfocitária quando comparados os grupos operados sem ou com circulação extracorpórea (ANOVA bicaudal para medidas repetidas, p>0,05). Considerando todos os pacientes estudados, houve uma elevação da expressão proporcional de CD25 e CD69 em linfócitos T (CD3+) e B (CD19+). Nos linfócitos T, o valor proporcional médio mais elevado (+ EP) de CD69 foi observado 6 horas após terem sido completadas as anastomoses (+75 + 476%) e CD25 teve uma elevação mais gradual, com o pico de seu valor médio (+48 + 24 %) ocorrendo 24 horas após a revascularização. Em linfócitos B, o pico do valor médio de CD69 (+104 + 269 %) ocorreu também após o fim das anastomoses. CD25 teve seu pico de valor médio (+150 + 773 %) 112 horas após a revascularização e seu último valor medido ainda estava elevado. A expressão de CD26 em linfócitos T teve um aparente declínio nos seus valores proporcionais médios (-42 + 32 %) 12 horas após o fim das anastomoses. Não houve diferença significativa na elevação enzimática entre os dois grupos (teste estatístico >0,05). No ecocardiograma, o grupo operado sem circulação extracorpórea apresentou diminuição do volume diastólico (p=0,001) de da fração de ejeção (P=0,012), enquanto no grupo com circulação extracorpórea, diminuíram os volumes diastólico (p=0,006) e sistólico (p=0,01). Conclusões: 1) Comparando a cirurgia de revascularização miocárdica com circulação extracorpórea, a cirurgia sem circulação extracorpórea não reduz a ativação dos linfócitos. 2) A cirurgia de revascularização miocárdica produz uma ativação precoce dos linfócitos, com aumento da expressão de CD69 e CD25 em linfócitos T (CD3+) e B (CD19+), em sangue periférico. A elevação precoce de CD69, e elevação mais tardia de CD25, pode indicar duas partes de uma seqüência de ativação linfocitária. 3) O comportamento das enzimas cardíacas e dos achados ecocardiográficos não sugere benefício da cirurgia sem circulação extracorpórea sobre o dano miocárdio.