[Immune response during laparoscopic and open living donor nephrectomy. An experimental pig model]. / Respuesta inmunohumoral durante la nefrectomía abierta y laparoscópica de donante vivo. Modelo porcino experimental.

INTRODUCTION: It's been demonstrated laparoscopic access determines a lower surgical stress, by measurement of several markers as different interleuquines (IL) or C-reactive protein (CRP). Endothelin 1 (ET-1) is a powerful vasoconstrictor produced in renal endothelium scarcely studied in laparoscopy. The objective of this study is to analyze immune response during laparoscopic and open donor nephrectomy, in a porcine experimental model by means of measuring IL-2, 10, tumoral necrosis factor alpha (TNFalpha), CRP and ET-1. METHODS: Twenty pigs underwent left nephrectomy, 10 by laparoscopy and 10 by open approach in an experimental model. Both groups were monitorized IL-2, 10, TNF alpha, ET-1 at basal, immediately post surgery, first, third, fifth and seventh days after procedure. RESULTS: The comparative analysis between groups demonstrated a significant increase in levels of CRP (1.44+/-0.88 vs 1.32+/-0.14 mg/dl, p=0.046), TNF alpha (131.14+/-41.37 vs 57.19+/-23.71 pg/ml, p>0.001) and ET-1 (0.91+/-0.49 vs 0.56+/-0.5 fmol/ml, p=0.001) of open nephrectomy group, as a higher levels of IL-2 in laparoscopic group. CONCLUSIONS: Open donor nephrectomy determines a higher immune response than laparoscopic approach. The importance of this fact over the ischemia-reperfusion syndrome or the immediate function of graft is not clearly established.

[Experimental models for research and training in renal transplant]. / Modelos experimentales para la investigación y el entrenamiento en trasplante renal.

An update on aspects and use of different experimental models applied in kidney transplant research is presented . This paper includes qualities, as long as similarities between most frequently used animal models and human clinical standards. Contributions of those models based on microsurgical or laparoscopic techniques are revised. The physiological consequences (hemodynamic, immunologic) of surgical technique (laparoscopy), applied in experimental models as long as non-heart beating organ donor models and organ preservation methods are also reviewed. Finally, an update of those models applied in research in prothocols of either immunosupression or xenotransplant is done.

[Experimental pancreatic islet transplant into the genito-urinary tract simultaneous to kidney transplant]. / Trasplante experimental de islotes de pancreas en el tracto genitourinario asociado al trasplante renal.

INTRODUCTION AND OBJECTIVES: Simultaneous kidney and pancreas transplant is a good treatment for both renal and pancreas insufficiency. Experimental apply of genitourinary tract for pancreas implantation is reported in this work. MATERIAL AND METHOD: Twenty animals aged as average 5.5 monts (SD 1.1) and an average weight of 53 kgr were submitted to this protocol. In the day 1 a left nephrectomy is completed and the graft is perfused with University of Wisconsin solution. A partial pancreatectomy is completed at following, isolation of pancreatic islets by colagenase enzymatic digestion. Islets are dryed with Ditizone and culptured for 24 hours at 37 degrees C and 5% CO2. Day-2 a right nephrectomy is performed and orthotopic renal autotransplant using the left kidney is completed. Pancreatic islets are transplanted in 4 different locations of the genitourinary tract: renal subcapsular space, bladder submucosae, testis parenchyma and vas deferens. Day-7, all the animals were sacrifized to complete pathological study. RESULTS AND CONCLUSIONS: Viable islets were isolated in bladder submucosae and testis after transdeferential injection.

[Comparative analysis of renal graft function after open vs. laparoscopic nephrectomy: experimental model]. / Análisis comparativo de la función del injerto renal de donante vivo tras nefrectomía abierta y laparoscópica: modelo experimental.

INTRODUCTION: Living donor renal transplant reports a higher patient and graft survival in comparison to cadaver donor and represents a good alternative facing the current lack of organs for transplant. GOALS: To analyze comparatively in an experimental model (pig) the influence of ischemia-reperfusion and functional outcome of renal graft retrieved by open Vs laparoscopic nephrectomy. MATERIAL AND METHODS: 30 lab pigs were nephrectomized (left kidney): 15 by laparoscopy and 15 by open surgery, as living donors, in a model of renal autotransplant. Renal blood flow (RBF) was measured by means of an electromagnetic probe and creatinine levels during the first week after the implant. RESULTS: Comparative analysis of RBF during the immediate 60 min after unclamping showed a significant reduction of average RBF in laparoscopic group in comparison to open group (p < 0.001), with a more evident reduction of RBF in the laparoscopic group during the 5-min period after unclamping (p < 0.001) and a progressive recuperation of RBF during the 1st hour, slowest in laparoscopic group. Creatinine levels in the first week after the transplant decreased progressively from 1.3 to 0.8 mgrs/dl in the open group and from 2 to 1.1 mg/dl in laparoscopic group (p < 0.001). CONCLUSIONS: Renal grafts retrieved by laparoscopy presents a more evident ischemia-reperfusion syndrome shown by a lower average RBF after unclamping and a significant deterioration of renal function during the first week after transplant.

Respuesta inmunohumoral durante la nefrectomía abierta y laparoscópica de donante vivo. Modelo porcino experimental / Immune response during laparoscopic and open living donor nephrectomy. An experimental pig model

Introducción: Se ha demostrado la menor agresividad quirúrgica provocada por el abordaje laparoscópico, en base a la medición de diversos marcadores de estrés postquirúrgico, entre los que se encuentran distintas interleuquinas (IL) y la proteína C reactiva (PCR). La endotelina 1 (ET-1) es un vasoconstrictor potente producido en el endotelio renal escasamente analizado en el curso de la cirugía laparoscópica. El objetivo del trabajo es analizar comparativamente la respuesta inmunohumoral inducida por las nefrectomías laparoscópica y abierta en un modelo experimental porcino, en base a la cuantificación de la PCR, las IL-2, 10, el factor de necrosis tumoral alfa (TNF alfa), y la ET-1.Material y métodos: Se analizan comparativamente dos grupos de cerdos de 25-40 Kg, un grupo CONTROL (N=10) y grupo LAPAROSCÓPICO (N=10), a los que se les realiza una nefrectomía abierta o laparoscópica respectivamente. Se determinó en sangre venosa periférica los niveles de PCR, IL-2, IL-10, TNF α y ET-1. Las determinaciones analíticas se realizaron en los momentos: basal, postcirugía, 1, 3, 5, y 7 días postquirúrgico. Resultados: El análisis comparativo de ambos grupos demuestra un aumento estadísticamente significativo de la PCR(1,44+ 0,88 vs 1,32 + 0,14 mg/dl, p=0,046), TNF α (131,14 + 41,37 vs 57,19 + 23,71 pg/ml, p>0,001) y ET-1 (0,91 + 0,49vs 0,56 + 0,5 fmol/ml, p=0,001) del grupo abierto en comparación con el grupo control, así como una elevación de la IL-2 en el grupo laparoscópico. Conclusiones: La respuesta inmunohumoral inducida por la nefrectomía abierta es superior a la de la nefrectomía laparoscópica en el curso de la donación. La importancia de este hecho en el síndrome isquemia reperfusión o la función inmediata del injerto no está claramente establecida (AU)

Introduction: It’s been demonstrated laparoscopic access determines a lower surgical stress, by measurement of several markers as different interleuquines (IL) or C- reactive protein (CRP). Endothelin 1 (ET-1) is a powerful vasoconstrictor produced in renal endothelium scarcely studied in laparoscopy. The objective of this study is to analyze immune response during laparoscopic and open donor nephrectomy, in a porcine experimental model by means of measuring IL-2,10, tumoral necrosis factor α (TNFα), CRP and ET-1.Methods: Twenty pigs underwent left nephrectomy, 10 by laparoscopy and 10 by open approach in an experimental model. Both groups were monitorized IL-2, 10, TNF α, ET-1 at basal, immediately post surgery, first, third, fifth and seventh days after procedure. Results: The comparative analysis between groups demonstrated a significant increase in levels of CRP (1,44 + 0,88vs 1,32 + 0,14 mg/dl, p=0,046), TNF α (131,14 + 41,37 vs 57,19 + 23,71 pg/ml, p>0,001) and ET-1 (0,91 + 0,49 vs 0,56+ 0,5 fmol/ml, p=0,001) of open nephrectomy group, as a higher levels of IL-2 in laparoscopic group. Conclusions: Open donor nephrectomy determines a higher immune response than laparoscopic approach. The importance of this fact over the ischemia-reperfusion syndrome or the immediate function of graft is not clearly established (AU)

Modelos experimentales para la investigación y el entrenamiento en trasplante renal / Experimental models for research and training in renal transplant

Introducción y objetivos: Se presenta una revisión sobre las diferentes características y el uso de los distintos modelos experimentales utilizados para el trasplante renal (TR). Esta revisión incluye las cualidades, así como sus semejanzas a los humanos, de las especies más frecuentemente utilizadas. Se revisan las aportaciones de los diferentes modelos al entrenamiento de las diferentes técnicas quirúrgicas como la laparoscopia o la microcirugía. Se repasan sus contribuciones al estudio y la investigación en campos como los efectos hemodinámicos o inmunológicos del neumoperitoneo, las técnicas de donante a corazón parado o las diferentes formas de preservación de los injertos. Por último, se realiza una revisión de los diferentes modelos utilizados para la investigación de los distintos protocolos de inmunosupresión así como el xenotrasplante

Introduction and objetives: An update on aspects and use of different experimental models applied in kidney transplant research is presented . This paper includes qualities, as long as similarities between most frequently used animal models and human clinical standards. Contributions of those models based on microsurgical or laparoscopic techniques are revised. The physiological consequences (hemodynamic, immunologic) of surgical technique (laparoscopy), applied in experimental models as long as non-heart beating organ donor models and organ preservation methods are also reviewed. Finally, an update of those models applied in research in prothocols of either immunosupression or xenotransplant is done

Trasplante experimental de islotes de páncreas en el tracto genitourinario asociado al trasplante renal / Experimental pancreatic islet transplant into the genito-urinary tract simultaneous to kidney transplant

Conceptualmente el trasplante de páncreas (TP) asociado al trasplante renal (TR) puede resolver la insuficiencia renal crónica (IRC) y la diabetes (DM). Aunque el lugar de implantación más frecuentemente utilizado es la vena porta, el tracto genitourinario puede ser adecuado desde un punto de vista técnico durante el TR. 20 animales con una edad media de 5,5 (SD 1,1) meses y una mediana de peso de 53 (30,102) kg se sometieron al siguiente protocolo experimental. El primer día, se lleva a cabo la nefrectomía izquierda y el injerto es perfundido con solución de Wisconsin, lo que se sigue de una pancreatectomía distal y el aislamiento de islotes por medio de la digestión enzimática con Colagenasa. Los islotes son teñidos con el colorante vital Ditizona (DTZ) y cultivados durante 24 horas a 37º y 5% de Co2. El día 2 se realiza la nefrectomía derecha y un TR ortotópico del injerto renal izquierdo preservado. Los islotes son trasplantados en 4 localizaciones diferentes en el tracto genitourinario: el espacio subcapsular del injerto renal, en la submucosa de vejiga, en el parénquima testicular y por vía deferencial. El día 7, los animales son sacrificados para estudio histopatológico. Se demostraron islotes viables en la submucosa vesical y en el testículo tras infusión por vía deferencial

Introduction and objectives: Simultaneous kidney and pancreas transplant is a good treatment for both renal and pancreas insufficiency. Experimental apply of genitourinary tract for pancreas implantation is reported in this work. Material and method. Twenty animals aged as average 5.5 monts (SD 1.1) and an average weight of 53 kgr were submitted to this protocol. In the day 1 a left nephrectomy is completed and the graft is perfused with University of Wisconsin solution. A partial pancreatectomy is completed at following, isolation of pancreatic islets by colagenase enzymatic digestion. Islets are dryed with Ditizone and culptured for 24 hours at 37ºC and 5% CO2. Day-2 a right nephrectomy is performed and orthotopic renal autotransplant using the left kidney is completed. Pancreatic islets are transplanted in 4 different locations of the genitourinary tract: renal subcapsular space, bladder submucosae, testis parenchyma and vas deferens. Day-7, all the animals were sacrifized to complete pathological study. Results and conclusions: Viable islets were isolated in bladder submucosae and testis after transdeferential injection

Análisis comparativo de la función del injerto renal de donante vivo tras nefrectomía abierta y laparoscópica: modelo experimental / Comparative analysis of renal graft fuction after open vs laparoscopic nephrectomy: experimental model

Introducción: El trasplante renal (TR) de donante vivo presenta una supervivencia del injerto y del paciente superior al TR procedente de cadáver y representa una alternativa eficaz frente al problema de la escasez de órganos. Objetivo: Analizar comparativamente en un modelo experimental en cerdo, la influencia del síndrome de isquemia repercusión y la evolución funcional del injerto renal extraído mediante nefrectomía abierta y laparoscópica. Material y métodos: 30 cerdos fueron sometidos a nefrectomía izquierda: 15 por laparoscopia y 15 por vía abierta, como donantes vivos en un modelo de autotrasplante renal. Se midió el flujo sanguíneo renal (FSR) postdesclampaje mediante sonda electromagnética y los niveles de creatinina (Cr) durante la primera semana postrasplante. Resultados: El análisis comparativo del FSR en la 1ª hora postTR objetivó: una disminución significativa del FSR medio en el grupo de laparoscopia frente al abierto (p<0,001), con una reducción del FSR en los primeros 5 minutos más acusado en el grupo laparoscópico (p<0,001), y una recuperación progresiva del FSR durante la 1ª hora, que es más lenta para el grupo laparoscópico. Los niveles de Cr en la primera semana postrasplante descendieron progresivamente desde 1,3 a 0,8 mg/dl en el grupo abierto, y de 2 a 1,1 mg/dl en el grupo laparoscópico (p<0,001). Conclusiones: Los injertos renales extraídos vía laparoscópica presentan una acentuación del síndrome de isquemiareperfusión manifestado por un FSR postdesclampaje inferior al FSR prenefrectomía y un deterioro significativo de la función renal durante la primera semana postrasplante

Introduction: Living donor renal transplant reports a higher patient and graft survival in comparison to cadaver donor and represents a good alternative facing the current lack of organs for transplant. Goals: To analyze comparatively in an experimental model (pig) the influence of ischemia-reperfusion and functional outcome of renal graft retrieved by open Vs laparoscopic nephrectomy. Material and methods: 30 lab pigs were nephrectomized (left kidney): 15 by laparoscopy and 15 by open surgery, as living donors, in a model of renal autotransplant. Renal blood flow (RBF) was measured by means of an electromagnetic probe and creatinine levels during the first week after the implant. Results: Comparative analysis of RBF during the immediate 60 min after unclamping showed a significant reduction of average RBF in laparoscopic group in comparison to open group (p<0.001), with a more evident reduction of RBF in the laparoscopic group during the 5-min period after unclamping (p<0.001) and a progressive recuperation of RBF during the 1st hour, slowest in laparoscopic group. Creatinine levels in the first week after the transplant decreased progressively from 1.3 to 0.8 mgrs/dl in the open group and from 2 to 1.1 mg/dl in laparoscopic group (p<0.001). Conclusions: Renal grafts retrieved by laparoscopy presents a more evident ischemia-reperfusion syndrome shown by a lower average RBF after unclamping and a significant deterioration of renal function during the first week after transplant

[Modification of the hemodynamic parameters and peripheral vascular flow in a porcine experimental of model of laparoscopic nephrectomy]. / Modificaciones de los parámetros hemodinámicos y de los distintos flujos vasculares periféricos en modelo experimental porcino de nefrectomía laparoscópica.

OBJECTIVES: It has been demonstrated that abdominal high-pressure and the use of CO2 pneumoperitoneum induce changes of the cardiovascular and respiratory systems, attributable to two factors: changes of the cardiac output (CO) and hypercarbia. Other modifications derived from these facts include changes of the systemic vascular resistances (SVR), blood pressure (BP), central venous pressure (CVP), vascular changes like modifications of the renal blood flow (RBF), carotid flow (CF), portal flow, and hepatic artery flow (HAF). Our objective is to analyze the hemodynamic modifications induced by pneumoperitoneum on renal blood flow, carotid flow, portal flow and hepatic artery flow in a porcine experimental model. METHODS: We compared two groups of pigs: CONTROL group (n = 10) and LAPAROSCOPIC group (n = 10), undergoing open or laparoscopic nephrectomy respectively. In every case, catheters were inserted into the right external jugular vein and femoral artery and cardiac output, CVP, blood pressure and systemic vascular resistances (calculated as RVS = (BP/CVP)x 80/CO); these measurements were taken at the following times: baseline, 5, 30, 60 min. and postoperatively. Renal blood flow, carotid flow, portal flow and hepatic artery flow were registered by means of an electromagnetic probe around the vessel 30 minutes after the start of surgery. RESULTS: Comparative analysis shows: an increase of cardiac output in the laparoscopic group, the difference which was maximal at 30 minutes (4.33 + 0.73 vs. 8 .54 + 1.26 l/min., p < 0.,001); a descent of the systemic vascular resistances (1118.81 + 302.52 vs. 663.37 + 81.45 dynes .s.cm5, p < 0.001) and an increase of blood pressure (66.5 + 11.52 vs. 80.25 + 2.49 mm Hg in the laparoscopic group. Flow analysis showed an increase of the carotid artery flow (125.73 + 41.69 vs. 291.7 + 51.52 ml/min., p < 0.001) and a decrease of portal flow (973.67 + 131.70 vs. 546.83 + 217.53 ml/min., p = 0.001) and hepatic artery flow (278.00 + 94.71 vs. 133.33 + 112.32 ml/min., p = 0.03) in the laparoscopic group. There were no significant differences in renal blood flow with the volume expansion used. CONCLUSIONS: Laparoscopic nephrectomy conditions an increase of carotid flow, probably secondary to the increase of cardiac output, and also a diminishment of hepatic perfusion, both arterial and portal. Nevertheless, volume expansion and the limitation of intra-abdominal pressure to 12 mm Hg enable to maintain similar renal blood flow in both groups.

[Comparative analysis about hemodynamic and renal blood flow effects during open versus laparoscopic nephrectomy. An experimental study]. / Análisis comparativo de las modificaciones hemodinámicas y del flujo sanguineo renal (FSR) durante la nefrectomía abierta y laparoscópica. Modelo experimental.

BACKGROUND: The increase of intraabdominal pressure to 10 mmHg provokes a decrease of renal blood flow (RBF). Pneumoperitoneum during laparoscopic techniques with intra-abdominal pressure (IAP) to 15 mmHg, results in a decrease in RBF, urine output and glomerular filtration rate (GFR). PURPOSE: Analyze the changes in RBF, urine output an GFR in a porcine experimental model during open vs laparoscopic nephrectomy. MATERIALS AND METHODS: 30 pigs (medium weigh= 22.6+3.2 Kg) were divided into two groups: Laparoscopic nephrectomy was performed using 15 pigs and open nephrectomy in 15 pigs, following a living donor nephrectomy autotransplantation model. Study parameters were urine volume and GFR baseline values, 30 and 60 minutes during nephrectomy. RBF was measured using an electromagnetic flow catheter around the main renal artery during the initial 60 minutes of nephrectomy. RESULTS: The laparoscopic technique was associated with a significant reduction of RBF (80+2.7 vs 262+3 ml/min) (p<0.005), diuresis (42%) and GFR (38%), vs the open group. CONCLUSIONS: Laparoscopic nephrectomy involves a significant reduction of RBF, GFR and diuresis, which is potentially transcendent in living donor nephrectomy and kidney transplantation.

Modificaciones de los parámetros hemodinámicos y de los distintos flujos vasculares periféricos en modelo experimental porcino de nefrectomía laparoscópica / Modification of the hemodynamic parameters and peripheral vascular flow in a porcine experimental of model of laparoscopic nephrectomy

Objetivo: Se ha demostrado que la hiperpresión abdominal y la utilización del neumoperitoneo con CO2, provocan cambios en los aparatos cardiovascular y respiratorio, atribuibles a dos factores: alteraciones en el gasto cardiaco (GC) e hipercarbia. Otras alteraciones derivadas de estos hechos son los cambios en las resistencias vasculares sistémicas (RVS), la tensión arterial (TA), la presión venosa central (PVC), cambios vasculares como las alteraciones en el flujo sanguíneo renal (FSR), flujo carotídeo (FAC), flujo portal (FP) y flujo de la arteria hepática (FAH). Nuestro objetivo es analizar las modificaciones hemodinámicas producidas por el neumoperitoneo sobre los FSR, FC, FP y FAH en modelo experimental porcino. Métodos: Se analizan comparativamente dos grupos de cerdos, un grupo CONTROL (N=10) y grupo LAPAROSCÓPICO (N=10), a los que se les realiza una nefrectomía abierta o laparoscópica respectivamente. En ambos grupos se canaliza la vena yugular externa derecha y la arteria femoral y se monitoriza el GC, la PVC, la TA, las RVS (calculada mediante la fórmula RVS=(TA-PVC)*80/GC); estas determinaciones se realizan en los momentos: basal, 5, 30, 60 minutos y postcirugía. Mediante sonda electromagnética alrededor del vaso, se registran los FSR, FC, FP y FAH a los 30 minutos de iniciada la intervención quirúrgica. Resultados: El análisis comparativo de ambos grupos demuestra un aumento del GC en el grupo laparoscópico, cuya diferencia fue máxima a los 30 minutos (4,33 + 0,73 vs 8,54 + 1,26 l/min, p< 0,001); un descenso de las RVS (1118,81 + 302,52 vs 663,37 + 81,45 dinas x s x cm-5 p< 0,001) y un aumento de la TA del grupo laparoscópico (66,5 + 11,52 vs 80,25 + 2,49 mm Hg, p= 0,004). El análisis de los flujos demostró un aumento del FAC (125,73 + 41,69 vs 291,70 + 51,52 ml/min, p<0,001) y una disminución del FP (973,67+ 131,70 vs 546,83+ 217,53 ml/min, p= 0,001) y del FAH (278,00 + 94,71 vs 133,33+112,32 ml/min, p=0,03) en el grupo laparoscópico. No existieron diferencias significativas en el FSR con la expansión de la volemia utilizada. Conclusiones: La nefrectomia laparoscópica condiciona un aumento del FC, posiblemente secundario al aumento del gasto cardiaco, así como un descenso de la perfusión hepática, tanto arterial como portal. Sin embargo, la expansión de la volemia y la reducción de la PIA a 12 mmHg permiten mantener el FSR semejante en ambos grupos (AU)

Objectives: It has been demonstrated that abdominal high-pressure and the use of C02 pneumoperitoneum induce changes of the cardiovascular and respiratory systems, attributable to two factors: changes of the cardiac output(CO) and hypercarbia. Other modifications derived from these facts include changes of the systemic vascular resistances (SVR), blood pressure (BP), central venous pressure (CVP), vascular changes like modifications of the renal blood flow (RBF), carotid flow (CF), portal flow, and hepatic artery flow (HAF). Our objective is to analyze the hemodynamic modifications induced by pneumoperitoneum on renal blood flow, carotid flow, portal flow and hepatic artery flow in a porcine experimental model. Methods: We compared two groups of pigs: CONTROL group (n = 10) and LAPAROSCOPIC group (n = 10), undergoing open or laparoscopic nephrectomy respectively. In every case, catheters were inserted into the right external jugular vein and femoral artery and cardiac output, CVP, blood pressure and systemic vascular resistances (calculated as RVS = (BP/CVP)x 80/CO); these measurements were taken at the following times: baseline, 5, 30, 60 min. and postoperatively. Renal blood flow, carotid flow, portal flow and hepatic artery flow were registered by means of an electromagnetic probe around the vessel 30 minutes after the start of surgery. Results: Comparative analysis shows: an increase of cardiac output in the laparoscopic group, the difference which was maximal at 30 minutes (4.33 + 0.73 vs. 8 .54+ 1.26 l/min., p < 0,001); a descent of the systemic vascular resistances (1118.81+ 302.52 vs. 663.37+ 81.45 dynes .s.cm5, p < 0.001) and an increase of blood pressure (66.5+ 11.52 vs. 80.25+ 2.49 mm Hg in the laparoscopic group. Flow analysis showed an increase of the carotid artery flow (125.73+ 41.69 vs. 291.7+ 51.52 ml/min., p < 0.001) and a decrease of portal flow (973.67+ 131.70 vs. 546.83+ 217.53 ml/min., p = 0.001) and hepatic artery flow (278.00+ 94.71 vs. 133.33+ 112.32 ml/min., p = 0.03) in the laparoscopic group. There were no significant differences in renal blood flow with the volume expansion used. Conclusions: Laparoscopic nephrectomy conditions an increase of carotid flow, probably secondary to the increase of cardiac output, and also a diminishment of hepatic perfusion, both arterial and portal. Nevertheless, volume expansion and the limitation of intra-abdominal pressure to 12 mm Hg enable to maintain similar renal blood flow in both groups (AU)

Análisis comparativo de las modificaciones hemodinámicas y del flujo sanguíneo renal (FSR) durante la nefrectomía abierta y laparoscópica. Modelo experimental / Comparative analysis about hemodynamic and renal blood flow effects during open versus laparoscopic nephrectomy. An experimental study

Introducción: El aumento de la presión intraabdominal (PIA) por encima de 10 mmHg conlleva una reducción del flujo sanguíneo renal (FSR). El neumoperitoneo inducido durante las técnicas laparoscópicas, condiciona presiones intraabdominales (PIA) próximas a 15 mmHg, circunstancia que reduce el FSR, la diuresis y el filtrado glomerular (FG). Objetivo: Analizar comparativamente en un modelo experimental en cerdo, las modificaciones del FSR, la diuresis y el FG inducidas por las nefrectomías abierta y laparoscópica. Material y métodos: Un total de 30 cerdos (peso medio = 22,6+3,2 Kg) han sido sometidos a nefrectomía izquierda: 15 por laparoscopia y 15 por vía abierta, como donantes vivos en un modelo de autotrasplante renal. Se midió la diuresis y el FG basales y a los 30 y 60 min del inicio de la nefrectomía. El FSR medio se determinó mediante sonda electromagnética en la arteria renal principal durante la primera hora de la cirugía. Resultados: Se objetivó una reducción significativa del FSR (80+2,7 vs 262+3 ml/min) (p<0,005) durante la nefrectomía laparoscópica frente a la abierta. También se demostró una disminución significativa de la diuresis (42%) y del FG (38%) del grupo laparoscópico frente al abierto. Conclusiones: La nefrectomía laparoscópica conlleva una disminución significativa del FSR, circunstancia potencialmente trascendente en el TR con donante vivo, así como del FG y de la diuresis

Background: The increase of intraabdominal pressure to 10 mmHg provokes a decrease of renal blood flow (RBF). Pneumoperitoneum during laparoscopic techniques with intra-abdominal pressure (IAP) to 15 mmHg, results in a decrease in RBF, urine output and glomerular filtration rate (GFR). PURPOSE: Analyze the changes in RBF, urine output an GFR in a porcine experimental model during open vs laparoscopic nephrectomy. Materials and methods: 30 pigs (medium weigh= 22.6+3.2 Kg) were divided into two groups: Laparoscopic nephrectomy was performed using 15 pigs and open nephrectomy in 15 pigs, following a living donor nephrectomy autotransplantation model. Study parameters were urine volume and GFR baseline values, 30 and 60 minutes during nephrectomy. RBF was measured using an electromagnetic flow catheter around the main renal artery during the initial 60 minutes of nephrectomy. Results: The laparoscopic technique was associated with a significant reduction of RBF (80+2.7 vs 262+3 ml/min) (p<0.005), diuresis (42%) and GFR (38%), vs the open group. Conclusions: Laparoscopic nephrectomy involves a significant reduction of RBF, GFR and diuresis, which is potentially transcendent in living donor nephrectomy and kidney transplantation

[A simplified method of continuous-wave Doppler noninvasive assessment of ventricular relaxation in mitral insufficiency]. / Método simplificado para el análisis no invasivo de la relajación ventricular mediante Doppler continuo en la insufficiencia mitral.

INTRODUCTION AND OBJECTIVES: The minimum value of dP/dT is a parameter of diastolic function that can be estimated noninvasively by analyzing the profile of velocity of the mitral regurgitant jet, recorded by continuous-wave Doppler. This estimation requires a complex analysis of the curves that impedes its practical use. Our objective was to validate a simplified method to estimate noninvasively the value of dP/dTmin when mitral regurgitation exists. We calculated the pendient of the profile of velocity of the curve of mitral regurgitation during its deceleration, between 3 and 1.5 m/s, an interval that defines a difference in pressure using the formula delta p = (4v2(1) - 4v2(2)). We divided this interval by the time needed by the jet to decelerate from 3 to 1.5 m/s, obtaining the rate of pressure decay, in mmHg/s. METHODS: We provoked mitral regurgitation in five pigs and registered dP/dT and the curve velocity of mitral regurgitation simultaneously, by micromanometer-tipped catheter and continuous-wave Doppler, respectively. The rate of pressure decay was calculated on the mitral regurgitation curve. RESULTS: We obtained 29 simultaneous registers. The coefficient for the correlationship between dP/dT and the rate of pressure decay was with an r value of 0.62 (p < 0.0001). The rate of pressure decay underestimated systematically the value of dP/dT. Intra and interobserver variability of TDP was 9 and 11%, respectively. CONCLUSIONS: This study validates a simplified method to estimate dP/dT noninvasively, with acceptable correlation with invasive measurements and adequate reproducibility.