Biomechanical and adhesion comparison of linea alba prophylactic reinforcement with coated and uncoated three-dimensional T-shaped mesh in rabbits

Abstract Purpose: Incisional hernia (IH) is a frequent complication of median laparotomy. The use of prophylactic mesh to reduce IH incidence has gained increasing attention. We hypothesized that in an animal model, linea alba prophylactic reinforcement with a three-dimensional T-shaped polypropylene mesh results in greater abdominal wall resistance. Methods: Study was performed in 27 rabbits. After abdominal midline incision, animals were divided into three groups according to the laparotomy closure method used: (1)3D T-shaped coated mesh; (2)3D T-shaped uncoated mesh; and (3) closure without mesh. After 4 months, each animal's abdominal wall was resected and tensiometric tests were applied. Results included IH occurrence, adhesions to the mesh, and wound complications. Results: There was no significant difference between the groups in maximum tensile strength (p=0.250) or abdominal wall elongation under maximum stress (p=0.839). One rabbit from the control group developed IH (p=1.00). Small intestine and colon adhesions occurred only in the uncoated mesh group (p<0.001) and the degree of adhesions was higher in this group compared to the coated mesh group (p<0.05). Conclusion: Use of the current 3D T-shaped prophylactic mesh model did not result in a significant difference in tensiometric measurements when compared with simple abdominal wall closure in rabbits.

Compreensão dos acadêmicos de medicina sobre os princípios de atendimento inicial aos pacientes queimados / Understanding of medical students about the principles of initial assistance for burn patients

OBJETIVO: Avaliar a compreensão dos acadêmicos de medicina sobre o atendimento inicial a pacientes queimados, bem como o aprendizado sobre a temática ao longo do curso. MÉTODO: Trata-se de um estudo transversal descritivo realizado em uma instituição de ensino superior de Minas Gerais, por meio da aplicação de um questionário validado por Balan e colaboradores. A coleta de dados ocorreu entre março e outubro de 2020, com 92 acadêmicos do 1° ano e 45 acadêmicos do 6° ano de medicina. As análises foram realizadas no software R versão 4.0.3. Descritas por frequências absolutas e relativas, desvio-padrão, teste Exato de Fisher, teste Qui-quadrado e teste de Mann-Whitney. RESULTADOS: Constatou-se que 6,67% dos acadêmicos do 6° ano acertaram acima de 80% das questões e 2,17% do 1° ano. A média de acertos, em porcentagem, no 6° ano foi 63,1±10,3 versus 47,0±16,9 no 1° ano. O tema de maior desconhecimento foi reanimação volêmica, cujo, 93,3% acadêmicos do 6° ano contra 96,7% no 1° ano erraram. O exame básico, cuidados iniciais, cálculo da superfície corporal queimada e triagem foram áreas do conhecimento com maior percentual de acerto no 6° ano: 93,3%, 85,6±25,3%, 80% e 85,2±19,5%, respectivamente, enquanto os do 1° ano tiveram menos acertos. CONCLUSÃO: Verificou-se, pelo presente trabalho, que apesar do aumento de acertos em comparação com o 1° ano, algumas condutas médicas iniciais necessárias aos pacientes queimados como reposição volêmica, cuidados locais e antibioticoterapia não são compreendidas pelos acadêmicos do 6° ano, na maior parte da amostra estudada.

OBJECTIVE: To evaluate the understanding of medical students about the initial care for burn patients, as well as learning about the theme throughout the course. METHOD: This is a cross-sectional descriptive study carried out in a higher education institution in Minas Gerais, through the application of a questionnaire validated by Balan and collaborators. Data collection took place between March and October 2020, with 92 students from the 1st year and 45 students from the 6th year of medicine. The variables were presented by absolute and relative frequencies and standard deviation. RESULTS: It was found that 6.67% of the 6th grade students answered correctly above 80% of the questions and 2.17% of the 1st year. The average number of correct answers in the 6th year was 63.1±10.3 versus 47.0±16.9 in the 1st year. The theme of greatest ignorance was volemic resuscitation, whose 93.3% 6th graders against 96.7% in 1st grade missed. The basic exam, initial care, calculation of the burned body surface and screening were fields of knowledge with the greatest percentage of correct answers in the 6th year: 93.3%, 85.6±25.3%, 80%, and 85.2±19.5%, respectively, while those in the 1st year had less correct answers. CONCLUSION: It was found, in the study, that despite the increase in correct answers compared to the 1st year, some initial medical procedures necessary for burned patients, such as: volume replacement, local care and antibiotic therapy, are not understood by 6th graders, in most of the studied sample.

Comparative study of intraperitoneal adhesions related to light-weight polypropylene mesh and type I polymerized and purified bovine collagen coated light-weight polypropylene mesh in rabbits

Abstract Purpose: To compare the effectiveness of light-weight polypropylene mesh coated with polymerized and purified bovine type I collagen (Surgidry HNB) in the treatment of abdominal wall defect and the degree of adhesion formation. Methods: Two types of polypropylene mesh were implanted after creation of defect measuring 6.0cm X 5.5cm in the anterior abdominal wall of 32 male New Zealand breed rabbits, divided in two groups (n = 32): (1) light-weigh macroporous polypropylene, (2) type I polymerized and purified bovine collagen coated light-weigh macroporous polypropylene. These animals were further accessed for adhesions, histological evaluation of inflammation and wall's thickness. Results: The percentage of the area adhered in group 1 (62.31 ± 16.6) was higher compared to group 2 (22.19 ± 14.57) (p <0.05). There was an association between the percentage of the covered area by adhesions and the type of adhesion, toughness and the scores obtained by the adhesion score by correlation analysis (p <0.05). There was no difference between the groups in any variables in relation to the degree of inflammation. Conclusion: The purified type I bovine collagen coated light-weigh polypropylene mesh showed to be effective in the repair of abdominal wall defects and reducing adhesion formation.

Treatment of abdominal wall hernia with suture, or polypropylene, or collagen prosthesis

ABSTRACT PURPOSE: To develop an experimental model for incisional hernias and to compare morphological and functional aspects of hernia repairs by suture, polypropylene mesh and collagen mesh. METHODS: A defect measuring 7cm x 2cm was created in the anterior abdominal of 28 New Zealand male rabbits, divided into four groups (n = 7): (1) control, (2) suture of the anterior sheath of the rectus abdominal muscle, (3) setting of polypropylene mesh, and (4) setting of collagen mesh. On the 90th postoperative day, the animals were examined to verify the presence of incisional hernia. Samples of abdominal wall and scar were collected for histological study. RESULTS: Incisional hernia was identified in 85.7% of the control group, 57.1% of the suture group, 42.9% of the collagen mesh group, and none in the polypropylene mesh group (p = 0.015). Mesh exposure could be identified in 71.4% of the animals in group 3 and in no animal in group 4 (p = 0.021). The polypropylene mesh is effective in the treatment of abdominal wall defects, causing an intense inflammatory reaction. CONCLUSION: The collagen mesh is biocompatible, producing a minimal inflammatory reaction, but fails in the treatment of abdominal wall defects.