Bioprosthetic mesh of bacterial cellulose for treatment of abdominal muscle aponeurotic defect in rat model

The use of meshes for treatment of hernias continues to draw attention of surgeons and the industry in the search of an ideal prosthesis. The purpose of this work is to use meshes manufactured from bacterial cellulose, evaluate their organic tissue interaction and compare with an expanded polytetrafluorethylene (ePTFE's) prosthesis used to repair acute defect of muscle aponeurotic induced in rats. Forty-five male Wistar rats were classified using the following criteria: (1) surgical repair of acute muscle aponeurotic defect with perforated bacterial cellulose film (PBC; n = 18); (2) compact bacterial cellulose film (CBC; n = 12) and (3) ePTFE; (n = 15). After postoperative period, rectangles (2 × 3 cm) including prosthesis, muscles and peritoneum were collected for biomechanical, histological and stereological analysis. In all cases, the maximum acceptable error probability for rejecting the null hypothesis was 5 %. Between PBC and CBC samples, the variables of strain (P = 0.011) and elasticity (P = 0.035) were statistically different. The same was found between CBC and ePTFE (elasticity, P = 0.000; strain, P = 0.009). PBC differed from CBC for giant cells (P = 0.001) and new blood vessels (P = 0.000). In conclusion, there was biological integration and biomechanical elasticity of PBC; therefore, we think this option should be considered as a new alternative biomaterial for use as a bio prosthesis.

Cardiocirculatory changes in hemorrhagic shock induced in pigs submitted to three distinct therapeutic methods

PURPOSE: To evaluate and compare the response of pigs submitted to hemorrhagic shock and treated using three different strategies. METHODS: Thirty-five Dalland pigs were divided into four groups: Control; Bleeding; Saline and Saline + Red Cell Concentrate. Parameters evaluated: heart rate (HR), mean arterial blood pressure (MAP) and central vein pressure (CVP).Hemorrhagic shock was induced by removing (624.25±64.55), (619.30±44.94) and (664.23±39.96) ml of blood respectively, with the following treatment: Bleeding Group - zero volume replacement; Saline Group - replacement with 676 ml of 0.9% saline solution; Saline + Red Cell Concentrate Group - replacement with 440 ml of 0.9% saline solution + 291 ml of red cell concentrate. The treatment was evaluated after 10 (T3), 30 (T4), 45 (T5) and 60 (T6) minutes. RESULTS: HR: No statistically significant difference was found between the Bleeding and Saline [p=1.000], Bleeding and Saline + Red Cell Concentrate [p=1.000], and Saline and Saline + Red Cell Concentrate [p=0.721] groups. MAP; Significant differences were found between all the groups studied. CVP: No significant difference was found between the groups. CONCLUSION: Non-replacement and euvolemic resuscitation maintained a satisfactory hemodynamic pattern in controlled severe hemorrhagic shock in swine. The euvolemic replacement strategies exceeded the limit values of MAP for rebleeding.

An experimental study of the electrical activity of the bypassed stomach in the Roux-en-Y gastric bypass

BACKGROUND: Surgical options for morbid obesity are diverse, and the Roux-en-Y gastric bypass, initially described by Fobi has gained popularity. Knowledge about the physiology of the bypassed stomach is limited because this newly produced segment of the stomach is inaccessible to endoscopic or contrast radiological studies. AIM: To evaluate the myoelectric activity of the bypassed stomach and its reply to the feeding. METHODS: An experimental protocol was conducted to evaluate postoperative gastric bypassed motility in dogs submitted to the Roux-en-Y gastric bypass procedure. Two groups of five animals were studied on postoperative fasting and after a standard meal, recording electrical response and control activity. Both control and Roux-en-Y gastric bypass operated study group had a pair of electrodes placed on three points of the remaining stomach: fundus, body and antrum. Data registration was performed after complete ileus resolution, and analysed with DATA Q Inst. series 200. RESULTS: The results achieved on the conditions of this study suggest that: 1. the remaining stomach maintain the same pattern of motility; 2. there is a reduced fasting electromyography activity following the Roux-en-Y gastric bypass procedure; 3. significantly reduced fasting electric control activity when compared both groups, and a markedly reduced fasting response electric activity and; 4. the electric response to the feeding kept the same standard of the stomach, however in a statistically reduced way. CONCLUSION: The electrical activity of the bypassed stomach of Roux-en-Y gastric bypass procedure kept the same pattern but in a statistically reduced number of contraction.

Desvios porta-jugular e cava-jugular passivos em cães: Investigação de pressões sangüíneas

Os principais objetivos dos desvios veno-venosos durante o transplante ortotópico de fígado são: atenuação da estase venosa subdiafragmática, manutenção do retorno satisfatório de sangue ao coração e perfusão tissular eficiente. Investigações sobre PP, PVCIIH, PVC, PAM e PPR, bem como <FONT FACE="Symbol">D</font> PP e <FONT FACE="Symbol">D</font> PVCIIH foram conduzidas em seis cães, sob anestesia geral, com fígados perfundidos pela Artéria Hepática, submetidos a desvios porta-jugular e cava-jugular passivos durante 2 horas. Estes desvios não foram capazes de evitar estagnação de sangue na VP e VCIIH, acarretando estase e menor retorno sangüíneo ao coração, sugeridos por aumentos significativos de PP e PVCIIH e quedas significantes nos níveis de PVC. Os valores de PAM não apresentaram diferenças significativas em relação ao tempo T0, na maior parte dos tempos avaliados, enquanto que os valores de PPR foram significativamente menores que os verificados no tempo T0, na maioria dos tempos estudados. Tais pressões mantiveram-se, respectivamente, acima de 100 e 50 mm de Hg, atribuindo-se tais resultados, em parte, à vasoconstricção arteriolar generalizada. Incrementos de pressão na VP (<FONT FACE="Symbol">D</font> PP) foram significativamente menos elevados que aqueles verificados na VCIIH (<FONT FACE="Symbol">D</font> PVCIIH), atribuindo-se tal diferença à complacência esplâncnica. Decréscimos ulteriores dos níveis de PP e PVCIIH sugerem queda do fluxo arterial para os territórios esplâncnico e sistêmico, decorrente de diminuição do retorno sangüíneo ao coração. Determinações de PP, PVCIIH, PVC, PAM e PPR podem constituir meio prático de avaliação hemodinâmica do desvio veno-venoso.