Reparação da parede abdominal com membranas acelulares de pericárdio bovino - Parte I - Achados clínicos e radiológicos / Abdominal wall repair with acellular bovine pericardial membranes - Part I - Clinical and radiological findings

Introdução: Reduzindo os índices de recidiva de forma impactante, o emprego de biomateriais como "telas de reforço" na reparação de diferentes defeitos da parede abdominal tornou-se rotina quase obrigatória para o sucesso dessas reparações. A partir da década de 1990 houve a introdução de matrizes biológicas acelulares, iniciando-se assim uma nova era na reparação dos defeitos da parede abdominal. O objetivo é avaliar a funcionalidade do pericárdio bovino acelularizado em reparações da parede abdominal. Método: Trinta pacientes foram submetidos a reparação de defeitos da parede abdominal, com biopróteses acelulares de pericárdio bovino, perfazendo um total de 40 implantes anatomicamente individualizados. O seguimento médio foi de 31 meses, sendo os pacientes avaliados clinicamente e radiologicamente. Em três casos foram feitas biópsias das áreas implantadas permitindo análise histológica do material. Resultados: Não se observou recidiva das herniações em nenhum dos casos, tanto clinica como radiologicamente. Também não houve registro de hematomas, infecções ou qualquer fenômeno de natureza reacional local ou sistêmica. Radiologicamente, não foi possível visualizar as matrizes no local de implantação em qualquer dos períodos de pós-operatório analisados. Conclusão: As matrizes mostraram similaridade às demais membranas biológicas descritas na literatura internacional. Representando uma importante atualização e evolução conceitual, as membranas acelulares de pericárdio bovino podem ser incorporadas ao arsenal terapêutico nas reparações de parede abdominal.

Introduction: Reducing recurrence rates significantly, the use of biomaterials as "reinforcement meshes" in the repair of different abdominal wall defects has become an almost mandatory routine for the success of these repairs. From the 1990s onwards, acellular biological matrices were introduced, thus beginning a new era in the repair of abdominal wall defects. The objective is to evaluate the functionality of the acellularized bovine pericardium in abdominal wall repairs. Method: Thirty patients underwent repair of abdominal wall defects using acellular bovine pericardium bioprostheses, making a total of 40 anatomically individualized implants. The average follow-up was 31 months, with patients being evaluated clinically and radiologically. In three cases, biopsies were taken from the implanted areas, allowing histological analysis of the material. Results: No recurrence of herniations was observed in any of the cases, both clinically and radiologically. There were also no records of bruises, infections or any phenomenon of a local or systemic reaction nature. Radiologically, it was not possible to visualize the matrices at the implantation site in any of the postoperative periods analyzed. Conclusion: The matrices showed similarity to other biological membranes described in the international literature. Representing an important update and conceptual evolution, acellular bovine pericardial membranes can be incorporated into the therapeutic arsenal in abdominal wall repairs.

Reparação da parede abdominal com membranas acelulares de pericárdio bovino - Parte II - Análises histológicas e morfométricas / Repair of the abdominal wall with acellular bovine pericardial membranes - Part II - Histological and morphometric analyses

Introdução: Análise histológica é a principal ferramenta de avaliação de biopróteses acelulares, em sua maioria em caráter experimental. O objetivo é analisar histologicamente a matriz acelular de pericárdio bovino em reparações de parede abdominal implantada em humanos. Método: De uma série de 30 reparações com a membrana, 3 pacientes foram submetidas a revisão cirúrgica não relacionada aos implantes, aos 13, 22 e 23 meses de pós-operatório, obtendo-se biópsias das áreas previamente implantadas. Além da avaliação dos aspectos básicos de biocompatibilidade e neoformação tecidual, as lâminas foram digitalizadas e submetidas a análise computadorizada com o software ImageJ para quantificação da cinética de degradação das membranas, associada à análise da dimensão fractal das amostras. Os valores obtidos para porcentagens de membrana residual tiveram suas médias comparadas por análise de variância (ANOVA) e pelo teste T de Student não pareado, também utilizado para os valores da quantificação da dimensão fractal. Resultados: Foi demonstrada a biocompatibilidade do material, com neoformação tecidual, deposição de colágeno e tecido celularizado de aspecto normal, sem reações locais importantes. Fragmentos residuais da membrana foram quantificados em 40%±7% aos 13 meses, em 20%±6% aos 22 meses e em 17%±6% aos 23 meses de pós-operatório, com a análise da dimensão fractal indicando uma progressiva degradação dos implantes, com significância estatística entre 13 meses e as amostras tardias. Conclusão: Os resultados atestaram a funcionalidade do pericárdio bovino acelular sob diferentes níveis de estresse mecânico nas reparações da parede abdominal em humanos.

Introduction: Histological analysis is the main tool for evaluating acellular bioprostheses, mostly on an experimental basis. The objective is to histologically analyze the acellular matrix of bovine pericardium in abdominal wall repairs implanted in humans. Method: From a series of 30 repairs with the membrane, 3 patients underwent surgical revision unrelated to the implants at 13, 22, and 23 months postoperatively, obtaining biopsies of the previously implanted areas. In addition to evaluating the basic aspects of biocompatibility and tissue neoformation, the slides were digitalized and subjected to computerized analysis with the ImageJ software to quantify the kinetics of membrane degradation associated with the analysis of the fractal dimension of the samples. The values obtained for percentages of residual membrane had their means compared by analysis of variance (ANOVA) and the unpaired Student's T test, also used for the fractal dimension quantification values. Results: The biocompatibility of the material was demonstrated, with tissue neoformation, collagen deposition, and cellularized tissue with a normal appearance without important local reactions. Residual fragments of the membrane were quantified at 40%±7% at 13 months, at 20%±6% at 22 months, and at 17%±6% at 23 months postoperatively, with the analysis of the fractal dimension indicating a progressive degradation of implants, with statistical significance between 13 months and late samples. Conclusion: The results confirmed the functionality of the acellular bovine pericardium under different levels of mechanical stress in abdominal wall repairs in humans.

Gluteal Implant-Associated Anaplastic Large Cell Lymphoma.

The association of anaplastic large cell lymphoma (ALCL) to breast implants (breast implant-associated ALCL) has brought back the discussion on the clinical safety of the use of silicone implants. A 63-year-old woman came to our institution in early 2015, reporting a gluteal augmentation with silicone implants in 2006 and a recent increasing volume and distortion of the left buttock. Radiologic imaging showed a large amount of fluid collection around the implant. The left side implant was removed and the capsule was left intact, presupposing a future reimplantation. The fluid collected was positive for Staphylococcus aureus. Three years later, she presented again with a new seroma on the explanted side and was submitted to total capsulectomy and fluid drainage, and the material was submitted to laboratory examination. Culture results were negative. Pathologic preparation and sections of the capsule and lumps showed large cells characterized by horseshoe-shaped nuclei. Immunohistochemistry was positive for CD30/CD4 and negative for anaplastic lymphoma kinase, confirming the presence of ALCL, then associated with gluteal implant, an event not described in literature. Positron emission tomography/computed tomography and bone marrow biopsy were performed, and neither showed any other sites involved. The same disease in a new location introduces important discussions about the understanding of this abnormality and poses certain risks and safety issues to clinical scenarios to be discussed. Regardless of whether it is a breast implant-associated ALCL or a gluteal implant-associated ALCL, now we are probably facing an implant augmentation-associated disease and a new international alert should be addressed to the scientific community. CLINICAL QUESTION/LEVEL OF EVIDENCE:: Therapeutic, V.

The use of a retroauricular fascioperichondrial flap in the recreation of the antihelical fold in prominent ear surgery.

The surgical treatments for prominent ears are on the basis of the approach over the basics of the deformity decrease the concha-mastoid angle and create a new antihelical fold. The author describes a new retroauricular flap to be used in the recreation of the antihelical fold and critically analyzes the cosmetic results and complications. A skin ellipse is outlined on the posterior surface of the ear. After hydrodissection with anesthetic solution in the outlined area, the skin is removed as thin as possible over the superior mid ear, preserving the underlying connective tissue and perichondrium. A triangular flap is created in the superior third of the raw area and elevated in the subperichondrial plane. The fixation of the flap posteriorly allows the medialization of the upper pole, resulting in a natural antihelical fold. One hundred sixty-one otoplasties were performed in 82 patients (3 unilateral), 53 women and 29 men. Mean age was 19.2 years and mean follow-up time was 3.4 years. Loss of correction at the upper pole led to secondary correction in 12 ears (7.45%). Suture extrusion was observed in 7 ears (4.34%). Hypertrophic scarring developed in 3 ears (1.86%). The accumulated risk of reoperation was of 10.85% in 9 years. The retroauricular fascioperichondrial flap combined with other techniques may be used as a standard procedure in the surgical treatment of prominent ears.

Vegetable polyurethane resin implant in cranioplasty - experimental study in rabbits

An experimental model was used to evaluate a new biomaterial - a vegetable polyurethane resin, extracted from castor plant oil - for repairing cranial vault bone loss. Two cranial, 15 x 10 mm in total width diameter and periosteum-free, bone failures were performed in 31 adult rabbits on both sides of the parietal region. Failures were not repaired in the 13 animals that comprised the control group and 18 animals had defects repaired using a vegetable polyurethane resin implant. Macroscopic, radiological and histological assessments were performed at 2, 6, 12, 18 and 24 post-operative weeks. Regardless of the method of evaluation, no tissue repair by bone neo-formation could be observed in the control group in which bone failures were replaced by scar tissue. In the group with implants, as of 6 weeks, repair of defects by bone neogenesis in peripheral areas was observed with a progressive favorable development in late samples (18 and 24 weeks), along with osteogenesis, osteoconduction and osteopromotion. Statistical analyses confirmed that bone healling in the implanted defects was more significantly effective (p<0.05). No toxic or reactional phenomena secondary to the presence of the implants that were not incorporated in the observational period were detected. No osteoinductive proprieties of implants became evident.