Vanessa Carla Paiva

Effects of different preservation temperatures and periods menisci cellularity in rabbits

PURPOSE: Quantify the progressive decrease of the cellular viability of rabbit meniscus preserved for transplants over a 30 day period at different freezing temperatures. METHODS: 180 menisci were removed from 45 rabbits. Menisci were frozen from 2 to 30 days at -7.2°Celsius -21.4°Celsius and -73°Celsius. Four menisci from each temperature were thawed every two days and the number of present cells was quantified. RESULTS: On the 14th freezing day at -7.2°Celsius, there were 92.38% mean viable cells. However, as from the 16th day, there has been a significant 12% decrease (p = 0.001), as compared to 14th day mean. Mean cell viability at -21.4°Celsius and -73oCelsius, until the 16th day was statistically similar. As from the 18th day at -21.4°Celsius, there has been significant cell count decrease (p < 0.001), especially from the 28th (54.5%) to the 30th (30%) freezing day. The number of viable cells at -73 0Celsius has shown insignificant 2.3% decrease (p = 1.000) from the 28th (40.2%) to the 30th (37.9%) day. CONCLUSION: The amount of viable meniscus cells is similar up to the 14th day of preservation, under any of the used temperatures. However, from the 14th day to the 30th day, the amount of viable cells is smaller in lower temperatures.PURPOSE Quantify the progressive decrease of the cellular viability of rabbit meniscus preserved for transplants over a 30 day period at different freezing temperatures. METHODS 180 menisci were removed from 45 rabbits. Menisci were frozen from 2 to 30 days at -7.2 degrees Celsius -21.4 degrees Celsius and -73 degrees Celsius. Four menisci from each temperature were thawed every two days and the number of present cells was quantified. RESULTS On the 14th freezing day at -7.2 degrees Celsius, there were 92.38% mean viable cells. However, as from the 16th day, there has been a significant 12% decrease (p = 0.001), as compared to 14th day mean. Mean cell viability at -21.4 degrees Celsius and -73 degrees Celsius, until the 16th day was statistically similar. As from the 18th day at -21.4 degrees Celsius, there has been significant cell count decrease (p < 0.001), especially from the 28th (54.5%) to the 30th (30%) freezing day. The number of viable cells at -73 degrees Celsius has shown insignificant 2.3% decrease (p = 1.000) from the 28th (40.2%) to the 30th (37.9%) day. CONCLUSION The amount of viable meniscus cells is similar up to the 14th day of preservation, under any of the used temperatures. However, from the 14th day to the 30th day, the amount of viable cells is smaller in lower temperatures.

Medial meniscus transplantation using cyanoacrylate in rabbits

PURPOSE To evaluate meniscal transplantation using as fixation method a synthetic glue derived from cyanoacrylate acid. METHODS Twenty rabbits were used, of which 10 for autologous transplantation and 10 for homologous transplantation. For the autologous transplantation the meniscus was removed, and then transplanted in the same animal, using the synthetic glue. For the homologous transplantation, the study was divided into two stages: 1--Removal of the meniscus which was maintained at a temperature of 73 C. 2--Use of cyanoacrylate acid-derived surgical adhesive for meniscal retransplantation in a different rabbit 30 days after the transplant. RESULTS Due to complications, euthanasia had to be anticipated to the 15th day in the homologous group and to the 18th day in the autologous group. Macroscopically, knees submitted to transplantation presented whitish secretions from the surgical incision up to deep planes. Necrosis was observed in both groups. Statistical analysis has shown that mild (p=0.043) and moderate (p=0.001) complications emerged in a significantly earlier way in the homologous group, where euthanasia was also performed earlier (p=0.005). CONCLUSION Synthetic surgical adhesives derived from cyanoacrylate acid promoted cortical to medullary bone necrosis bone in both groups.

Avaliação do posicionamento da agulha de veress durante o estabelecimento do pneumoperitônio pela técnica fechada, em porcos

BACKGROUND: To establish reliable evidence regarding the adequate positioning of the tip of a Veress needle in the interior of the peritoneal sac during the establishment of the pneumoperitoneum by the closed technique. METHODS: In 11 pigs, the needle was introduced in the peritoneal sac through the left hipocondrium. Tests of positioning of the tip of the instrument were carried out. Gas (CO2) was injected, and pressures, flows and volumes were registered periodically. The correct intraperitoneal position of the needle was confirmed and, subsequently, removed, being reintroduced in the right hipocondrium and placed under direct vision in the pre-peritoneal space. The same parameters were surveyed. RESULTS: The test of the draining was always positive in the peritoneum. Resistance to the infusion of serum in the peritoneal sac was not observed, but resistance was detected on 45.5% of cases in the pre-peritoneal space. Some serum was recouped in 63.5% of cases in the peritoneal sac and in 54.5% in the pre-peritoneal space. The dripping flowed freely in 66.6% of cases in the peritoneal sac and in 45.5% in the pre-peritoneal space. In the peritoneal sac, = 5mmHg initial pressure increased gradually during 120 seconds until reaching 15 mmHg. In the pre-peritoneal space, the initial pressure was of 15mmHg and oscillated between 12 and 15mmHg. The volume of gas injected was of 1500 ml in the peritoneal sac and of 100 ml in the pre-peritoneal space. CONCLUSION: Initial pressure of ±5mmHg is indicative of the tip of the needle being placed in the peritoneal sac, inside of which there should fit ten times more gas than in the pre-peritoneal space. When the tip of the Veress needle is placed in the interior of the peritoneal sac, the increase of intraperitoneal pressures and volumes can be predicted by statistics.

The role of fibrin glue and suture on the fixation of ultra frozen preserved meniscus transplantation in rabbits

Objective: To evaluate the ability of fibrin adhesive in promoting the meniscus fixation within two, four and eight weeks compared to the conventional soft-tissue suture technique. Materials and Methods: 36 right medial menisci of rabbits preserved at negative 73° Celsius for 30 days were transplanted to animals of the same sample and fixed with soft-tissue suture or fibrin glue. After 2, 4 or 8 weeks, the appearance of the menisci and the quality of fixation were macroscopically checked and evaluated by a scoring system. The findings were subjected to the statistical study of variance analysis (p ≤ 0.05%). Results: The deep-frozen meniscus preservation maintained the integrity of the meniscus transplant, and, macroscopically, there was no significant reduction of the length of the meniscus in all post-transplant periods (p = 0.015). The menisci fixed with fibrin showed slight changes in color and surface roughness. There were no signs of rejection or infection in both groups. Suture fixation scoring was superior (p = 0.015) in all periods (80% of total fixation) as compared to the setting promoted by fibrin (20% of total fixation). Conclusion: The homologous transplantation of the meniscus of rabbits experienced various degrees of integration to the knee according to the fixation method; the surgical soft tissues suturing technique was shown to be superior in the evaluation of scores compared to the fixation with fibrin adhesive.

O papel do adesivo de fibrina e da sutura na fixação do transplante de menisco preservado por ultracongelamento em coelhos

OBJETIVO: Avaliar a capacidade do adesivo de fibrina em promover a fixacao do menisco ao longo de duas, quatro e oito semanas comparando com a tecnica convencional de fixacao por sutura a tecidos moles. METODOS: 36 meniscos mediais direitos de coelhos preservados a 73°C negativos por 30 dias foram transplantados para os animais da mesma amostra e fixados com sutura ou cola de fibrina. Apos duas, quatro ou oito semanas a aparencia dos meniscos e a qualidade da fixacao foram verificadas macroscopicamente e avaliadas por um sistema de escores. Os achados foram submetidos a estudo estatistico de analise de variância por postos (p < 0,05%). RESULTADOS: A preservacao por ultracongelamento manteve a integridade macroscopica dos meniscos transplantados. Apos todos os periodos pos-transplante tambem nao houve reducao significante da extensao dos meniscos (p = 0,015). Os meniscos fixados com fibrina mostraram discretas alteracoes de coloracao e rugosidade de superficie. Nao houve sinais de rejeicao ou infeccao em ambos os grupos. A avaliacao por escores da fixacao pela sutura foi superior (p = 0,015) em todos os periodos (80% de fixacao total) do que a fixacao promovida pela fibrina (20% de fixacao total). CONCLUSAO: O transplante homologo do menisco de coelho sofreu diferentes graus de integracao ao joelho de acordo com a tecnica de fixacao; a tecnica operatoria com sutura aos tecidos moles mostrou-se superior na avaliacao de escores em relacao a fixacao com adesivo de fibrina.

Morfologia da Acta Cirúrgica Brasileira normas e exigências para a publicação

The authors present the Acta Cirurgica Brasileira style and the main characteristics for manuscripts submitted to publication according to Vancouver style. It is recommended that authors must follow the instructions to authors in the journal. Technical requirements for submission of manuscripts are pointed out. It is emphasized that the journal follows the Uniform Requirements for Manuscripts Submitted to Biomedical Journals of the International Committee of Medical Journal Editors.