[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.

[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.

[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.

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

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

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)