Polypropylene meshes coated with chitosan/polyethylene glycol for the reconstruction of the abdominal wall: an experimental study in rats / Telas de polipropileno revestidas com o filme de quitosana/polietilenoglicol para a reconstrução da parede abdominal: estudo experimental em ratos

The aim of this study was to characterize the tissue reactions triggered by the polypropylene mesh coated with chitosan and polyethylene glycol film, and if it's able to prevent the formation of peritoneal adhesions. Defects in the abdominal wall of rats were induced and polypropylene meshes coated with chitosan/polyethylene glycol (CPEG group, n= 12) and uncoated (PP control group, n= 12) were implanted. On the fourth and forty-fifth postoperative day the formation of adhesion and the tissue reaction to the biomaterial was evaluated through histological and histochemical analysis. The area (P= 0.01) and severity (P= 0.002) of the adhesion was significatively less in the CPEG group. On the fourth day the foreign body reaction was less intense in CPEG group (P= 0.018) and the production of collagen fibers was more intense in this group (P= 0.041). The tissue reactions caused by the biomaterials were similar on the 45th day, with the exception of the high organization of collagen fibers in the CPEG group. The CPEG meshes did not fully prevent the formation of adhesions, but minimized the severity of the process. The foreign body reaction promoted by polypropylene meshes coated with CPEG is less intense than that triggered by uncoated polypropylene meshes.(AU)

O objetivo deste estudo foi caracterizar as reações tissulares desencadeadas pela tela de polipropileno revestida com o filme de quitosana e polietilenoglicol e verificar se ela é capaz de prevenir a formação de aderências peritoneais. Um defeito na parede abdominal dos ratos foi realizado, e as telas de polipropileno revestidas com quitosana/polietilenoglicol (grupo CPEG, n= 12) e sem revestimento (grupo controle PP, n= 12) foram implantadas. No quarto e no 45º dia pós-operatório, avaliou-se a formação de aderências e a reação tecidual ao biomaterial por análise histológica e histoquímica. A área (P= 0,01) e a severidade (P= 0,002) da aderência peritoneal foram significativamente menores no grupo CPEG no 45º dia. No quarto dia, observou-se que a reação do corpo estranho foi menor no grupo CPEG (P= 0,018), e a produção de fibras de colágeno mais intensa (P= 0,041). As reações tissulares causadas pelos biomateriais implantados foram semelhantes no 45º dia, com exceção da melhor organização das fibras colágenas no grupo CPEG. As telas CPEG não impediram completamente a formação de aderências, porém minimizaram a gravidade do processo. A reação de corpo estranho promovida por telas de polipropileno revestidas com CPEG é menos intensa do que a desencadeada por telas de polipropileno não revestidas.(AU)

Therapeutic alternatives for the prevention of intra peritoneal adhesions

Intestinal adhesions are bands of fibrous tissue created by the intimate contact of two injured surface tissues; these appear in 93% of the patient undergoing intra-abdominal or gastrointestinal surgery. The comorbidities associated with the formation of adhesions have an impact on quality care offered to patients, leading to an increase in healthcare. Goals of this study was to perform a review that includes different therapeutic alternatives in basic and clinical research to prevent the formation of postoperative abdominal peritoneal adhesions. A bibliographic search was conducted in different databases including Pub med, Medline, Cochrane, science direct, from the years 2000 to 2018 using the keywords: gastrointestinal adhesions, small bowel obstruction, prophylaxis, treatment. Only experimental and clinical articles were selected. The development of peritoneal adhesions in most of the experimental studies occurred with cecal abrasion, studying the effect of biodegradable materials, drugs and gels such as mXG Hydrogel. Nanofiber membranes, agents created with recombinant technology such as periostin antisense oligonucleotide and aerosol applications such as polysaccharide 4DryField PH, are positioned to replace in the future the actual limited mechanical barriers application commonly used in abdominal surgery such as seprafilm and interceed. There are several anti-adhesion agents in experimental phase with different mechanism of action that could be used in the short term to prevent the formation of post-surgical intestinal adhesions. The inclusion of gastrointestinal surgeons in basic research is increasing and necessary with multidisciplinary collaboration. It is expected in short term the study and development of a greater number of materials to minimize tissue trauma and decrease the formation of post-surgical adhesions.

Papel del alopurinol en las adherencias peritoneales al colocar una malla de polipropileno: Estudio experimental en ratas / Role of alopurinol in peritoneal adherences when placing a polypropylene mesh: Experimental study in rats

Objetivo: Determinar el efecto del alopurinol en las adherencias peritoneales al colocar una malla de polipropileno. Sede: Cirugía Experimental de la Universidad de Guanajuato. Diseño: Estudio experimental, prospectivo, comparativo, controlado, doble ciego, con asignación al azar. Análisis estadístico: χ². Material y métodos: Se compararon dos grupos de 30 ratas Wistar cada uno, a quienes se les colocó una malla de polipropileno: el grupo A, sin tratamiento versus el grupo B, alopurinol a 25 mg/kg/día por sonda orogástrica. Resultados: Este estudio determinó que la prevalencia de adherencias protésicas-peritoneales viscerales en ratas Wistar, al colocar una malla de polipropileno, es del 100% sin tratamiento y con alopurinol. Conclusiones: No obtuvimos diferencia estadística del efecto beneficioso del alopurinol en la prevención de adherencias, esto puede hablarnos de que la acción del alopurinol sólo se ejerce en la prevención de adherencias cuando su etiología es la isquemia y no debido a la presencia de reacción a cuerpo extraño de tipo granulomatoso.

Objective: To determine the effect of allopurinol on peritoneal adhesions when placing a polypropylene mesh. Setting: Experimental Surgery Unit of the University of Guanajuato, México. Design: Experimental, prospective, comparative, controlled, double-blinded, randomized assignment study. Statistical analysis: χ². Material and Methods: We compared two groups of 30 Wistar rats each, in which we placed a polypropylene mesh: Group A, without treatment, versus group B with allopurinol at mg/kg per day administered through an orogastric catheter. Results: This study determined that the prevalence of visceral peritoneal-prosthetic adhesions in Wistar rats when placing a polypropylene mesh is of 100% with and without allopurinol treatment. Conclusions: We did not obtain statistical differences of the beneficial effect of allopurinol in preventing adhesions, this can indicate that allopurinol's effect is only exerted in preventing adhesions when they are due to ischemia but not when they are caused by a granulomatous-type foreign body reaction.

Current status of the use of antiadhesive agents for gastric cancer surgery: a questionnaire survey in South Korea / 대한외과학회지

PURPOSE: The aim of this study was to investigate the current status of the use of antiadhesive agents (AAdAs) via a questionnaire and to discuss the availability of AAdAs. METHODS: The survey was sent to a list of members that was approved by the Korean Gastric Association. The survey included questions on AAdA use by surgeons, the type of AAdAs used, and the reasons for not using AAdAs. Surgeons were also asked to describe complications related to AAdAs, and the reliability of its use. RESULTS: The response rate was 21%. The rates of frequent use stratified by procedure were 26.9% (14/52) for open gastrectomy, 5.9% (3/51) for laparoscopic gastrectomy, and 31.5% (17/54) for surgery for postoperative bowel obstruction (P < 0.01). After including data from the occasional use group, the corresponding values were 51.9% (27/52), 19.6% (10/51), and 70.4% (38/54), respectively (P < 0.01). Sefrafilm and Guardix were most commonly used for open procedures. Guardix and Interceed were most commonly used for laparoscopic surgery. The primary reasons for nonuse of AAdAs were ineffectiveness and high cost. Ten percent (4/40) of surgeons observed complications associated with AAdAs. A minority (17.3%, 9/52) had positive attitudes toward AAdAs. The majority of respondents expressed neutral (73.1%, 38/52) or negative (9.6%, 5/52) attitudes toward AAdAs. CONCLUSION: The low use rates of AAdAs in gastric cancer surgery may be attributable to perceptions that AAdAs are ineffective, unreliable, and costly. We anticipate the emergence of promising antiadhesive strategies that reach far beyond the limitations of current products.

Prevención de adherencias peritoneales postoperatorias mediante uso de antagonista de receptores de neurokinina tipo 1 / Peritoneal adhesions prevention: neurokinin-1 receptor antagonist

Background: The fibrinolytic activity plays an important role in Peritoneal Adhesions (PA) develop-ment. It's well known that de substance P decreased the fibrinolysis by binding the neurokinin-1 receptor, improving the PA formation. Objectives: To evaluate the effectiveness of intraperitoneal treatment with a Neurokinin-1 receptor antagonist (NK-R1A) in peritoneal adhesión prevention in animal model. Materials and Methods: In 40 male wistar rats, PA were induced, and then randomly assigned to 2 groups: A group treated with Aprepitant (NK-Rl A), and a control group. The animals were killed at 7 or 14 postoperative day, and the number, severity and histopathology of PA were evaluated. Results: NK-Rl A decreased the number (40 percent less) and severity (p = 0.001) of PA when compare to control group. The NK-Rl A group had less PA in manipulated and no manipulated organs during surgery. Besides presented less fibrosis (p = 0.001), less inflamation (p = 0.005) and less vascular proliferation (p = 0.047) than control group. Conclusions: The NK-Rl A is effective as in PA prevention.

Introducción: La actividad fibrinolítica juega un papel fundamental en el desarrollo de las adherencias peritoneales (AP), y se conoce que la Sustancia P al actuar sobre receptores de neurokinina tipo 1 a nivel peritoneal, disminuye la fibrinólisis, favoreciendo la formación de las mismas. Objetivos: Evaluar la efectividad del tratamiento intraperitoneal con antagonista de receptores 1 de neurokinina (NK-R1A) en la prevención de AP en modelo animal. Materiales y Métodos: A 40 ratas wistar se les practicó cirugía formadora de AP y fueron distribuidas de forma aleatoria en 2 grupos, un grupo que recibió Aprepitant (NK-R1A), y el otro como grupo control. Los animales fueron sacrificados a los 7 ó 14 días, y se evaluó el número, severidad e histopatología de las AP. Resultados: El NK-Rl A disminuyó el número (40 por ciento menos) y severidad de las AP (p = 0,001) en relación al grupo control y presentó menos AP en órganos manipulados y no manipulados durante la cirugía. Ademßs presentó menor grado de fibrosis (p = 0,001), menor inflamación (p = 0,005) y menor proliferación vascular (p = 0,047) que el grupo control. Conclusión: El tratamiento peritoneal con NK-R1A es eficaz en la prevención de la formación de AP.

Antagonista de receptores de neurokinina tipo 1 versus ácido hialurónico/carboximetilcelulosa en la prevención de adherencias peritoneales postoperatorias: estudio experimental en modelo animal / Neurokinin 1 receptor antagonist versus hyaluronic acid-carboxymethylcellulose in the prevention of postoperative peritoneal adhesions: experimental study in biomodels

La actividad fibrinolítica juega un papel fundamental en el desarrollo de las adherencias peritoneales (AP), y se conoce que la sustancia P al actuar sobre receptores de neurokinina tipo 1 a nivel peritoneal, disminuyen la fibrinólisis, favoreciendo la formación de las mismas. La efectividad de antagonistas de estos receptores como tratamiento preventivo de AP, ha sido evaluada, obteniendose resultados favorables. Comparar la efectividad del tratamiento intraperitoneal con antagonista de receptores 1 de neurokinina (NK-RIA) versus gel de ácido hialurónico/carboximetilcelulosa (AH/CMC) en la prevención de AP en modelo animal. A 60 ratas Wistar se les practicó cirugía formadora de AP y fueron distribuidas de forma aleatoria en 3 grupos, un grupo que recibió aprepitant (NK_RIA), otro recibió gel de AH/CMC y un grupo control. Los animales fueron sacrificados a los 7 ó 14 días, y se evaluó el número, severidad e histopatología de las AP. Tanto el NK-RIA como el AC/CMC disminuyeron el número (40% y 38% respectivamente) y severidad de las AP (p=0,001 y p=0,029 rerspectivamente) en relación al grupo control, sin diferencias estadísticas entre ellos (p=0,806). El grupo de NK-RIA presentó menos AP en órganos no manipulados durante la cirugía en relación a los otros 2 grupos. Ambos tratamientos presentaron menor grado de fibrosis que el control, sin embargo el grupo de NK-RIA tuvo menor inflamación (P=0,005) y proliferación vascular (P=0,047) que el AH/CMC. El NK-RIA tiene alta eficacia previendo la formación de AP, equiparable a la gel de AH/CMC.

The fibrinolytic activity play an important role in the peritoneal adhesions (PA) development. It’s well known that of substance P decreased the fibrinolysis by binding the neurokinin-1 receptor, improving the PA formation. Lot of investigation have evaluated the efficacy in PA prevention of antagonist of these receptors, with very good result. To compare the effectivences of intraperitoneal treatment with a neurokin-1 receptor antagonist (NK-RIA) versus hyaluronic acid/carboxymethylcellulose (HA/CMC) gel, in peritoneal adhesion prevention in animal model. In 60 male Wistar rats, PA were induced, and then randomly assigned to 3 groups. A group treated with aprepitant (NK-RIA), a second group treated with HH/CMC and a control group. The animals were killed at 7 or 14 postoperative day, and the number, severity and histopathology of PA were evaluated. NK-RIA and HA/CMC decreased the number (40% and 38% respectively) and severity (p=0,001 and p=0,029 respectively) of PA when compare to control group. The NKRIA group had less PA in no manipulated organs in surgery that the others 2 groups. Both treatments presented less fibrosis that control, however the NK-RIA group presented less inflammation (p=0,005) and vascular proliferation (p=0,047) than HA/CMC group. The NK-RIA is as effective as HC/CMC in preventing PA.

Comparative Study of Reduction and Prevention of Surgery-induced Peritoneal Adhesion By Methylene Blue and Hyaluronate Sodium / 中国医师杂志

Objective To study comparatively reduction and prevention of surgery-induced peritoneal adhesion by methylene blue and hyaluronate sodium. Methods 46 patients with acute diffuse peritonitis or adhesion intestinal ileus were divided at random into 3 groups: methylene blue ( MB) group, hyaluronate sodium (HS) group and control ( C ) group. The alteration of postoperation recovery,serum MDA, TNF? and erythrocytes SOD in patients were investigated. Results The recuperation in group MB was better than in group C (P