Association of laboratory and radiologic parameters in the diagnosis of acute cholecystitis. / Asociación de parámetros analíticos y radiológicos en el diagnóstico de la colecistitis aguda.

INTRODUCTION AND OBJECTIVES: There is currently more evidence suggesting that early surgery should be the treatment of choice for acute calculous cholecystitis, although initial conservative treatment is also reported to be safe. Treatment decision depends on the conditions of the patient, surgical experience, and hospital infrastructure, given that early surgery cannot always be carried out. The aim of the present study was to correlate C-reactive protein values with other variables to determine those situations in which surgery cannot be delayed. MATERIALS AND METHODS: A retrospective study was conducted on patients admitted to the hospital from the emergency service with the diagnosis of acute calculous cholecystitis. The patients were divided into 2groups: 1) patients that required urgent cholecystectomy and 2) patients that responded well to conservative medical treatment and later underwent deferred cholecystectomy. RESULTS: A total of 238 patients (♂ 54.6%, ♀ 45.4%) were analyzed. Urgent surgery was performed on 158 patients, whereas the remaining 80 patients were released from the hospital following conservative treatment. The odds ratio of gangrenous cholecystitis presenting in acute cholecystitis for C-reactive protein was calculated in the logistic regression analysis, obtaining an OR of 1.088 and a 95% CI of 1.031-1.121. CONCLUSION: In patients diagnosed with acute calculous cholecystitis, the combination of elevated values of C-reactive protein levels, gallbladder wall thickness, and number of leukocytes was correlated with less favorable clinical and gallbladder histologic states, resulting in a greater need for urgent surgical treatment.

Tissue integration and biomechanical behaviour of contaminated experimental polypropylene and expanded polytetrafluoroethylene implants.

BACKGROUND: Infection is one of the most devastating complications following implantation of a prosthetic material. The aim of this study was to compare the behaviour of two biomaterials contaminated with Staphylococcus aureus or Staphylococcus epidermidis, used to repair abdominal wall defects. METHODS: Defects (7 x 5 cm) were created in the anterior abdominal wall of 60 white New Zealand rabbits and repaired using polypropylene or expanded polytetrafluoroethylene (ePTFE) prostheses. The site of repair had been previously inoculated with 10(6) colony-forming units/ml S. aureus or S. epidermidis. Seven and 30 days after implantation, prosthetic specimens were examined by light and scanning electron microscopy, and immunohistochemical and biomechanical analysis. RESULTS: No significant differences with respect to controls were observed in the S. epidermidis groups. Two animals inoculated with S. aureus died. S. aureus induced the appearance of denuded areas exposing the filaments in the polypropylene prostheses, whereas the ePTFE prostheses showed zones of erosion, disorganized tissue, haemorrhage and necrosis. The biomechanical strength of the contaminated implants was unaltered. CONCLUSION: Integration within host tissue was affected in the setting of S. aureus infection but the tensile strength of contaminated prostheses was not significantly reduced.

Peritoneal regeneration after implant of a composite prosthesis in the abdominal wall.

Prosthetic materials currently used to repair abdominal wall defects occasionally must be placed in direct contact with the visceral peritoneum. The prosthesis-peritoneum interface is the site of several possible problems, including the formation of adhesions and erosion of the intestinal loops, which may lead to the formation of fistulas. This investigation was designed to compare the behavior of two prosthetic biomaterials in composite form at the level of the peritoneum. Defects (7 x 5 cm) were created in the abdominal wall of 18 white New Zealand rabbits weighing approximately 2500 g. The defects (involving aponeurotic and muscular planes and the parietal peritoneum) were repaired with polypropylene (PL) + ePTFE (Preclude dura substitute) or Parietex composite (PC) prostheses. The prostheses were secured to the edges of the defect by continuous PL sutures interrupted at the corners of the implant. Three study groups were established according to the type of implant: group I (n = 6) (controls)--PL; group II (n = 6)--PL + ePTFE; and group III (n = 6)--PC. The animals were sacrificed 14 days after implant, and the prostheses were examined by light microscopy and scanning electron microscopy (SEM). The formation of adhesions at the prosthesis-visceral peritoneum interface were quantified according to a protocol previously described by us. The biomechanical resistance of the implant was evaluated using strips comprising prosthetic material and anchorage tissue. The Mann-Whitney U-test was used to compare data corresponding to each group. There was no postimplant mortality. No infection or rejection of the prosthesis was observed in any of the animals. Firm adhesions were detected in the PL implants, whereas in the PL + ePTFE and PC implants the adhesions were loose. The mean prosthetic surface areas covered by adhesions were 7.67, 0.10 and 0.19 cm2 for groups I, II, and III, respectively, showing a significant difference between values corresponding to groups I and II and to groups I and III (p < 0.05). Comparison of values recorded for groups II and III yielded no significant difference (p > 0.05). In groups II and III, the neoperitoneum was homogeneous and composed of organized and vascularized connective tissue covered by a mesoendothelium that was interrupted by accumulations of fibroblasts and white blood cells. In contrast, a disorganized neoperitoneum of rough texture was observed in the group I specimens. At times, areas of hemorrhage and necrosis corresponding to the sites of adhesion formation could be observed. Resistance to traction of composite implants (mean +/- SD: 15.72 +/- 1.32 and 15.89 +/- 2.73) was similar to that of the PL implants (15.03 +/- 2.92) (Mann-Whitney U-test, p < 0.05). It may be concluded that (1) composite prostheses show optimum behavior in terms of adhesion formation at the prosthesis-visceral peritoneum interface; (2) the neoperitoneum formed after the implant of a composite prosthesis almost physically and functionally replaces the normal peritoneum; (3) a significantly greater degree of peritoneal regeneration is achieved after implant of a PC prosthesis; and (4) there was no significant difference regarding biomechanical resistance between PL prostheses and PL + ePTFE and Parietex composites.

Use of composite prostheses in the repair of defects in the abdominal wall: prosthetic behaviour at the peritoneum.

OBJECTIVE: To compare the behaviour of two composite biomaterials in rabbit peritoneum. DESIGN: Animal study. SETTING: Faculty of Medicine, University of Alcalá, Spain. ANIMALS: 14 white New Zealand white rabbits divided into 2 groups of 7 each. INTERVENTIONS: Defects (7 x 5 cm) involving all the layers of the abdominal wall were created and repaired using Parietex Composite or Vypro prostheses. Fourteen days after implantation, prosthetic specimens were examined by microscopy, and morphometric and biomechanical analysis. MAIN OUTCOME MEASURES: Infection, healing, development of adhesions, and histological appearance of the interface. RESULTS: Firm adhesions were detected after the implant of Vypro while adhesion were loose in the Parietex group. The mean (SD) prosthetic surface area covered by adhesions was significantly greater in the Vypro group 22.3 (2.8) compared with 0.2 (0.02), p <0.01). The neoperitoneum formed after the implant of Parietex was well-organised and homogeneous and covered by a typical mesothelium, while in the Vypro it was disorganised, with a rough texture composed of prosthetic filaments and nodes. The neoperitonum was thicker in the Parietex group 154.0 (5.4) compared with 50.8 (2.3), p <0.05) while higher biomechanical resistance values were recorded in the Vypro group 30.4 (1.9) compared with 15.0 (2.73), p <0.05). CONCLUSIONS: While both biomaterials integrated well with tissue, Parietex behaved better at the peritoneal interface.

Reparación de defectos de pared abdominal con prótesis composite. Estudio del comportamiento peritoneal / Abdominal wall defect repair using a graft-prosthesis composite

Introducción. Los materiales protésicos actuales empleados para la reparación de defectos en la pared abdominal en algunas ocasiones tienen que ser implantados en contacto con el peritoneo visceral. Esta interfase prótesis/peritoneo visceral plantea en ocasiones problemas debido a la formación de adherencias y a la presencia en algunos casos de erosión en las asas intestinales, con posibilidad de formación de fístulas. El objetivo del presente trabajo ha sido realizar un estudio comparativo sobre el comportamiento peritoneal de dos materiales protésicos diseñados en forma de composite. Material y métodos. Se han empleado 14 animales (conejo blanco Nueva Zelanda) de un peso aproximado entre 2.000 y 2.500 g. Se crearon defectos de 7 * 5 cm en la pared anterior del abdomen que comprendían todos los planos (aponeurótico, muscular y peritoneo parietal), siendo reparados con prótesis de Parietex composite® (Pc) y Vypro® (Vy), que fueron ancladas en los márgenes del defecto con una sutura continua de polipropileno, interrumpida en los ángulos del implante. Se establecieron dos grupos de estudio. Grupo I (n = 7): implantes de Pc; Grupo II (n = 7): implantes de Vy. Los animales fueron sacrificados a los 14 día de la intervención quirúrgica. Se efectuaron estudios mediante microscopia óptica, electrónica de barrido (SEM) y morfometría a través de análisis de imagen computarizado. El estudio biomecánico se realizó con un tensiómetro Instron empleando tiras de 2 cm de ancho que comprendían el biomaterial y los tejidos de anclaje a la pared. El análisis estadístico de los resultados se efectuó empleando el test de la U de Mann-Whitney. Resultados. No hubo mortalidad, infección o rechazo en ninguno de los animales intervenidos. Las adherencias fueron firmes en los implantes de Vy y laxas en los de Pc. El área ocupada por las mismas fue para el Pc de 0,19 ñ 0,02 y para el Vy de 22,3 ñ 2,78, existiendo diferencias significativas entre los dos grupos (p < 0,01). El neoperitoneo formado en los implantes de Pc fue homogéneo y ordenado, muy vascularizado y tapizado por mesotelio típico. En los implantes de Vy el peritoneo neoformado presentaba una estructura desordenada, con una textura rugosa debido al relieve de los filamentos y nudos de la prótesis. El análisis morfométrico del peritoneo neoformado fue estadísticamente significativo, superior para el Pc (154,02 ñ 5,05) comparado con el Vy (50,83 ñ 9,18) (p < 0,05). Sin embargo, la resistencia tensiométrica puso de manifiesto diferencias significativas a favor del Vy (30,39 ñ 2,99) en relación con el Pc (15,03 ñ 2,92) (p < 0,05). Conclusiones. a) Los dos biomateriales tienen un buen comportamiento de integración tisular, siendo superior la resistencia biomecánica para el Vypro, y b) el comportamiento óp timo en la interfase peritoneal se consigue con el Parietex composite (AU)

Anestesia en un caso de reparación laparoscópica de hernia de Morgagni / Anesthesia for laparoscopic repair of a small bowel hernia

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