Development and assessment of an ex-vivo bench model aimed at laparoscopic ureteric reconstructive techniques.

INTRODUCTION/BACKGROUND: Reconstructive and ablative urologic techniques require special technical mastery, especially the intracorporeal suturing. OBJECTIVE: To report the subjective evaluation of a versatile ex-vivo model aimed to practice laparoscopic ureteric reconstructive techniques (LURT) on box-trainer. STUDY DESIGN: The model is a continuous portion of porcine urinary bladder ("dilated pelvis"), the vesico-ureteral joint ("stenosis") and healthy ureter. All 127 participants (n = 119 urologists and n = 8 paediatric surgeons) performed on the model laparoscopic Anderson-Hynes dismembered pyeloplasty, and then, in the animal model, different LURT procedures (ureteroneocystostomy, ureteric reimplantation and/or dismembered pyeloplasty). The model was subjectively evaluated (face and content validity), through a 12 items questionnaire, based on a Likert scale (1-5 points) and a global question (1-10 points). RESULTS: The total mean rating for 11/12 items was very high (>4points). Only one was rated under 3 points. The overall total mean rating from 1 to 10 points was very high (9.19 ± 0.82 points). In 10/12 items, expert's feedback (content validity) prevailed over non-experts (face validity). DISCUSSION/CONCLUSION: The model was highly accepted for the practice of LURT techniques. Additionally, it is cost-effective, easy to assemble, ethically considerate, and realistic.

Mechanical Intestinal Obstruction in a Porcine Model: Effects of Intra-Abdominal Hypertension. A Preliminary Study.

INTRODUCTION: Mechanical intestinal obstruction is a disorder associated with intra-abdominal hypertension and abdominal compartment syndrome. As the large intestine intraluminal and intra-abdominal pressures are increased, so the patient's risk for intestinal ischaemia. Previous studies have focused on hypoperfusion and bacterial translocation without considering the concomitant effect of intra-abdominal hypertension. The objective of this study was to design and evaluate a mechanical intestinal obstruction model in pigs similar to the human pathophysiology. MATERIALS AND METHODS: Fifteen pigs were divided into three groups: a control group (n = 5) and two groups of 5 pigs with intra-abdominal hypertension induced by mechanical intestinal obstruction. The intra-abdominal pressures of 20 mmHg were maintained for 2 and 5 hours respectively. Hemodynamic, respiratory and gastric intramucosal pH values, as well as blood tests were recorded every 30 min. RESULTS: Significant differences between the control and mechanical intestinal obstruction groups were noted. The mean arterial pressure, cardiac index, dynamic pulmonary compliance and abdominal perfusion pressure decreased. The systemic vascular resistance index, central venous pressure, pulse pressure variation, airway resistance and lactate increased within 2 hours from starting intra-abdominal hypertension (p<0.05). In addition, we observed increased values for the peak and plateau airway pressures, and low values of gastric intramucosal pH in the mechanical intestinal obstruction groups that were significant after 3 hours. CONCLUSION: The mechanical intestinal obstruction model appears to adequately simulate the pathophysiology of intestinal obstruction that occurs in humans. Monitoring abdominal perfusion pressure, dynamic pulmonary compliance, gastric intramucosal pH and lactate values may provide insight in predicting the effects on endorgan function in patients with mechanical intestinal obstruction.

Consecuencias renales de la hipertensión intraabdominal en modelo porcino. Búsqueda de la técnica indirecta de elección de la medida de la presión intraabdominal / Renal Consequences of Intraabdominal Hypertension in a Porcine Model. Search for the Choice Indirect Technique for Intraabdominal Pressure Measurement

Objetivo: Estudiar las consecuencias renales en un modelo porcino de hipertensión intraabdominal y determinar la técnica indirecta de elección para la medida de la presión intraabdominal. Material y métodos: Se utilizaron 30 cerdos divididos en 2 grupos, presión intraabdominal incrementada en 20 mm Hg y en 30 mm Hg. En ambos las presiones se registraron en 8 tiempos hasta3 horas con un insuflador de CO2. Se realizaron 3 medidas de la presión intraabdominal, una directa transperitoneal, empleando un catéter de Jackson-Prat conectado a un traductor depresión, y 2 indirectas, una transvesical mediante un sistema de Foley manómetro y otra transgástrica introduciendo en el estómago un catéter conectado a un monitor de presión con hardware electrónico. Se calculó la presión arterial media, el gasto cardiaco, la producción de orina y la creatinina sérica. Resultados: Hubo una mayor correlación entre la presión intraabdominal transvesical y la transperitoneal (R2 = 0,95). La media de la presión intraabdominal transgástrica fue menor quela transperitoneal en todos los tiempos. La presión arterial media descendió en ambos grupos observando diferencias significativas más precoces a 30 mm Hg (p < 0,020). La producción de orina fue menor a 30 mm Hg (9,63±1,57) vs. (3,26 ml±1,73). La creatinina aumentó en ambos grupos, siendo patológica a 30 mm Hg a partir de 1 h 20 min, existiendo diferencias entre presiones precoces (p < 0,027).Conclusiones: Hubo afectación renal más marcada a presiones de 30 mm Hg. La técnica transvesical mostró una mayor correlación con la técnica directa empleada, por lo que consideramos esta como la de elección (AU)

Objective: To study the effects on the renal system in a porcine model of intraabdominal hypertension, and to determine the indirect technique of choice for determination of the intraabdominal pressure. Material and methods: 30 pigs were used divided in two groups according with increased intraabdominal pressure values (20 mm Hg and 30 mm Hg). In both groups pressures were registered 8 times, summing up to 3 hours, with a CO2 insufflator. Three different measures of the intraabdominal pressure were taken: a direct transperitoneal measure, using a catheter of Jackson-Pratt connected to a pressure transducer, and two indirect measures, a transvesical by means of a Foley to manometer system, and a transgastric by introducing in the stomacha catheter connected to a pressure monitor with electronic hardware. Mean arterial pressure was calculated, along with the cardiac index, production of urine and serum creatinine. Results: There was a greater correlation between the transvesical and the transperitoneal intraabdominal pressures (R2 = 0,95). Average transgastric intraabdominal pressure was inferior to the transperitoneal indicator in all taken measurements. The average arterial pressure descended in both groups, with earlier significant differences observed at 30 mm Hg (p < 0,020).Urine production was lower at 30 mm Hg compared with the 20 mm Hg group (9,63±1,57 versus3.26 ml±1,73). Serum creatinine increased in both groups being pathological at 30 mm Hg after1 h 20 min, with existing differences between early pressures (p < 0,027).Conclusions: This study revealed marked renal affectation with higher severity at 30 mmHg pressures. The transvesical technique showed a greater correlation with the direct measurement technique used, defining this as the method of choice for determination of intraabdominal pressure (AU)

Renal consequences of intraabdominal hypertension in a porcine model. Search for the choice indirect technique for intraabdominal pressure measurement.

OBJECTIVE: To study the effects on the renal system in a porcine model of intraabdominal hypertension, and to determine the indirect technique of choice for determination of the intraabdominal pressure. MATERIAL AND METHODS: 30 pigs were used divided in two groups according with increased intraabdominal pressure values (20 mmHg and 30 mmHg). In both groups pressures were registered 8 times, summing up to 3 hours, with a CO2 insufflator. Three different measures of the intraabdominal pressure were taken: a direct transperitoneal measure, using a catheter of Jackson-Pratt connected to a pressure transducer, and two indirect measures, a transvesical by means of a Foley to manometer system, and a transgastric by introducing in the stomach a catheter connected to a pressure monitor with electronic hardware. Mean arterial pressure was calculated, along with the cardiac index, production of urine and serum creatinine. RESULTS: There was a greater correlation between the transvesical and the transperitoneal intraabdominal pressures (R(2)=0,95). Average transgastric intraabdominal pressure was inferior to the transperitoneal indicator in all taken measurements. The average arterial pressure descended in both groups, with earlier significant differences observed at 30 mmHg (p<0,020). Urine production was lower at 30 mmHg compared with the 20 mmHg group (9,63 ± 1,57 versus 3.26 ml ± 1,73). Serum creatinine increased in both groups being pathological at 30 mmHg after 1h 20 min, with existing differences between early pressures (p<0,027). CONCLUSIONS: This study revealed marked renal affectation with higher severity at 30 mmHg pressures. The transvesical technique showed a greater correlation with the direct measurement technique used, defining this as the method of choice for determination of intraabdominal pressure.

Desarrollo y sostenibilidad del recurso agua en Argentina; versión preliminar

Informe sobre el uso del agua en la Argentina, las tendencias de desarrollo y repercusiones sobre el medio ambiente. Preparado por el INCyTH como aporte para la elaboración del informe Argentino para la Conferencia Mundial sobre Medio Ambiente y Desarrollo de Río de Janeiro, Brasil 1992

Desarrollo y sostenibilidad del recurso agua en Argentina; versión preliminar

Informe sobre el uso del agua en la Argentina, las tendencias de desarrollo y repercusiones sobre el medio ambiente. Preparado por el INCyTH como aporte para la elaboración del informe Argentino para la Conferencia Mundial sobre Medio Ambiente y Desarrollo de Río de Janeiro, Brasil 1992