RESUMEN
BACKGROUND: Currently, the most commonly used site for clinical islet transplantation is the liver although it is far from being an ideal site. Low oxygen tension and the induction of an inflammatory response impair islet implantation and lead to significant early loss of islet. The present study aimed to investigate and compare the efficacy of islet transplantation to the ovary and kidney subcapsule in diabetic rats. METHODS: The study was performed with 3 groups of rats (control, ovary, and kidney subcapsule) including 6 Sprague female rats each. Diabetes model was created with the use of streptozotocin, and blood glucose levels of the rats were measured after 72 hours. Thirty days after the transplantation, blood samples were obtained from the rats, and then pancreas, kidney, and ovary specimens were fixed in 10% formaldehyde and the experiment completed. After staining with hematoxylin and eosin, the tissue samples were morphologically evaluated by a specialist histopathologist. RESULTS: Changes in mean blood glucose and C-peptide levels were statistically significant in the ovary and kidney subcapsule groups. Histologic examination revealed that granulosus insulin-bearing cells were detected in the islet grafts of both ovary and kidney subcapsule groups. The renal subcapsule group had inflammation signs on histologic examination. The islet cells of both ovary and renal subcapsule groups had no vacuolization. CONCLUSIONS: We showed that the ovary might be a new site for islet transplantation. Further research should be done on whether the initial results of this study can be reproduced in larger numbers of animal models and eventually in humans.
Asunto(s)
Diabetes Mellitus Experimental/cirugía , Trasplante de Islotes Pancreáticos/métodos , Riñón , Ovario , Animales , Glucemia/análisis , Péptido C/análisis , Diabetes Mellitus Experimental/patología , Femenino , Células Secretoras de Insulina/metabolismo , Islotes Pancreáticos/citología , Riñón/citología , Ovario/citología , Páncreas/metabolismo , Ratas , Ratas Sprague-Dawley , EstreptozocinaAsunto(s)
Puente Cardiopulmonar , Paro Cardíaco/cirugía , Trasplante de Hígado/efectos adversos , Puente Cardiopulmonar/efectos adversos , Resultado Fatal , Paro Cardíaco/diagnóstico , Paro Cardíaco/etiología , Paro Cardíaco/fisiopatología , Hemodinámica , Humanos , Fallo Hepático/etiología , Masculino , Persona de Mediana Edad , Factores de Riesgo , Resultado del TratamientoRESUMEN
BACKGROUND: This study investigated the effect of temporary occlusion of the aorta on the development of ischemia-reperfusion (I/R) injury of the visceral organs, the optimal timing of administration of resveratrol, and its mechanism of protection via inhibiting nitric oxide (NO) release with an NO synthase inhibitor. METHODS: Rabbits were divided into seven groups according to the administration period of resveratrol and/or N(G)-nitro-L-arginine methyl ester (L-NAME): control group; group 1, resveratrol during ischemic period; group 2, resveratrol during reperfusion period; group 3, L-NAME during ischemic period; group 4, L-NAME during reperfusion period; group 5, resveratrol during ischemic period and L-NAME during reperfusion period; group 6, L-NAME during ischemic period and resveratrol during reperfusion period. The infrarenal aorta was clamped for 30 min. Blood samples were taken for the biochemical assessment, and organ specimens were taken for pathological assessment at 24hr of reperfusion. RESULTS: In groups 5 and 6, the renal I/R injury was comparatively milder (I/R injury score 1.04+/-0.29 in control group, 0.25+/-0.17 in group 5, and 0.33+/-0.13 in group 6 [p<0.05]). The I/R injury of bowel was milder in group 5 (I/R injury score 1.8+/-0.80 in control group vs. 0.0+/-0.0 in group 5 [p<0.05]). CONCLUSION: The protective effects of resveratrol on organs that have high metabolic rate like kidney and bowel was proven histopathologically. It may be beneficial to use different pharmacological medications in different periods of the I/R damage as they represent different characteristics with and without oxygen. The combination of resveratrol and L-NAME against I/R injury appears to be an effective option in the near future.
Asunto(s)
Aorta/cirugía , Inhibidores Enzimáticos/administración & dosificación , NG-Nitroarginina Metil Éster/administración & dosificación , Óxido Nítrico Sintasa/antagonistas & inhibidores , Óxido Nítrico/metabolismo , Daño por Reperfusión/prevención & control , Estilbenos/administración & dosificación , Vísceras/irrigación sanguínea , Animales , Biomarcadores/sangre , Constricción , Modelos Animales de Enfermedad , Esquema de Medicación , Quimioterapia Combinada , Intestinos/irrigación sanguínea , Riñón/irrigación sanguínea , Hígado/irrigación sanguínea , Pulmón/irrigación sanguínea , Daño por Reperfusión Miocárdica/enzimología , Daño por Reperfusión Miocárdica/prevención & control , Óxido Nítrico Sintasa/metabolismo , Conejos , Daño por Reperfusión/enzimología , Daño por Reperfusión/patología , ResveratrolRESUMEN
Postoperative neurologic deficit is the most devastating complication after thoracoabdominal aortic aneurysm repair. Our aim was to investigate whether nebivolol has protective effects during ischemia or reperfusion and the most effective mechanism of protection via inhibiting nitric oxide (NO) release with an NO synthase inhibitor in an experimental model of spinal cord ischemia/reperfusion injury. Spinal cord ischemia was induced by occlusion of the infrarenal aorta for 30 min. Thirty-one rabbits were divided into five groups according to the administration period of nebivolol and/or N(G)-nitro-L-arginine methyl ester (L-NAME): control group; group NI, nebivolol during ischemic period; group NR, nebivolol during reperfusion period; group NILR, nebivolol during ischemic period and L-NAME during reperfusion period; and group LINR, L-NAME during ischemic period and nebivolol during reperfusion period. Blood samples were taken at both ischemia and reperfusion periods to obtain nitrite/nitrate levels. After neurologic evaluation at 24 hr of reperfusion, malondialdehyde (MDA) levels were measured. Neurologic impairment was significantly lower in group LINR (Tarlov score 3.4 +/- 0.6, p < 0.05). MDA levels were lower in nebivolol-treated animals, but the lowest value was achieved in the NR group, 35.6 +/- 2.7 nmol/g (p < 0.001). Nitrite levels were decreased significantly in all nebivolol-treated animals in the reperfusion period, but the lowest value was measured in the LINR group (455 +/- 137 vs. 1,760 +/- 522 nmol/mL, p < 0.001). Prophylactic use of nebivolol reduced neurologic injury, and combining with L-NAME provided the best clinical improvement by attenuating the inflammatory mileu in this experimental model. Combination of nebivolol and L-NAME appears to be an effective option for spinal cord protection against ischemia/reperfusion injury.
Asunto(s)
Benzopiranos/farmacología , Inhibidores Enzimáticos/farmacología , Etanolaminas/farmacología , NG-Nitroarginina Metil Éster/farmacología , Fármacos Neuroprotectores/farmacología , Óxido Nítrico Sintasa/antagonistas & inhibidores , Daño por Reperfusión/prevención & control , Isquemia de la Médula Espinal/tratamiento farmacológico , Médula Espinal/efectos de los fármacos , Animales , Aorta/cirugía , Benzopiranos/administración & dosificación , Constricción , Modelos Animales de Enfermedad , Quimioterapia Combinada , Inhibidores Enzimáticos/administración & dosificación , Etanolaminas/administración & dosificación , Peroxidación de Lípido/efectos de los fármacos , Malondialdehído/sangre , Destreza Motora/efectos de los fármacos , NG-Nitroarginina Metil Éster/administración & dosificación , Nebivolol , Fármacos Neuroprotectores/administración & dosificación , Nitratos/sangre , Óxido Nítrico/metabolismo , Óxido Nítrico Sintasa/metabolismo , Nitritos/sangre , Conejos , Daño por Reperfusión/etiología , Daño por Reperfusión/metabolismo , Daño por Reperfusión/fisiopatología , Médula Espinal/irrigación sanguínea , Médula Espinal/enzimología , Médula Espinal/fisiopatología , Isquemia de la Médula Espinal/complicaciones , Isquemia de la Médula Espinal/metabolismo , Isquemia de la Médula Espinal/fisiopatologíaRESUMEN
OBJECTIVES: The performance of small-diameter (3-5-mm) vascular grafts still poses a challenge in the field of vascular surgery. We present here our preliminary experience with implanting unique small-sized polycarbonate urethane vascular grafts in 7 dogs. MATERIAL AND METHODS: Each animal was implanted with 4 interposition grafts, 2 femoral and 2 carotid. No anti-thrombotic medication was administered. Doppler sonography was performed at 3-month intervals to examine for patency and flow characteristics. Animals were sacrificed electively at 3, 6 and 12 months. RESULTS: At 3 months, all grafts were patent. After 6 months, 3 grafts occluded and at 1 year a further 6 grafts occluded. Hence 9 of 28 grafts occluded (67.9% patency). During the study, no correlation could be established between flow velocity or resistance index and occlusion. Histopathology showed intimal hyperplasia to be the cause of occlusion. CONCLUSIONS: Compared to literature data on small-diameter grafts in the same position, ADIAM's Biomechanical grafts performed clearly better. Compliance data suggest a correlation between elastic compliance and patency.
Asunto(s)
Prótesis Vascular , Arterias Carótidas/cirugía , Arteria Femoral/cirugía , Poliuretanos , Animales , Perros , Femenino , Oclusión de Injerto Vascular/diagnóstico por imagen , Oclusión de Injerto Vascular/prevención & control , Supervivencia de Injerto , Masculino , Implantación de Prótesis , Ultrasonografía DopplerRESUMEN
We studied whether cardiopulmonary bypass (CPB) has any immediate impact on the initiation of antioxidative defenses in the body by measuring F(2)-isoprostanes and alpha- and gamma-tocopherol, respectively. 8-iso-PGF(2alpha) levels increased significantly within 3 minutes and until the end of CPB. alpha-Tocopherol levels increased gradually at 20 min during CPB and continued until 6 hours after CPB. gamma-Tocopherol levels followed a similar fashion at the end of CPB. 8-iso-PGF(2alpha) and tocopherol levels kept at basal level 12 and 24 hours post CPB. These findings suggest that an increased free radical-induced oxidative stress together with a gradual appearance of antioxidative defense system during and after CPB.
Asunto(s)
Puente de Arteria Coronaria , Estrés Oxidativo , alfa-Tocoferol/sangre , gamma-Tocoferol/sangre , Adulto , Anciano , Antioxidantes/análisis , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Free radicals are believed to be involved in postsurgery-related complications. We studied whether cardiopulmonary bypass (CPB) operation has any immediate impact on the initiation of oxidative stress and inflammatory response by measuring isoprostanes and prostaglandin F2alpha during and 24 h following CPB. The levels of 8-iso-PGF2alpha (a major F2-isoprostane and biomarker of oxidative stress) and 15-keto-dihydro-PGF2alpha (a major metabolite of PGF2alpha and biomarker of inflammatory response) were measured in frequently collected plasma samples before, during, and up to 24 h postsurgery in 21 patients. 8-Iso-PGF2alpha levels significantly increased within 3 min (p <.0001) and continued until 50 min (p <.0001) during CPB. On the contrary, no significant increase of inflammatory response indicator, 15-keto-dihydro-PGF2alpha was found during and up to 24 h postoperatively. These findings establish an increased free radical-induced oxidative stress activity rather than inflammatory response after CPB.
Asunto(s)
Puente Cardiopulmonar/efectos adversos , Dinoprost/análogos & derivados , Radicales Libres , Isoprostanos/sangre , Estrés Oxidativo , Adulto , Anciano , Dinoprost/química , Femenino , Humanos , Inflamación , Isquemia , Masculino , Persona de Mediana Edad , Modelos Químicos , Oxígeno/metabolismo , Prostaglandinas/metabolismo , Radioinmunoensayo , Factores de TiempoRESUMEN
BACKGROUND: Mechanical prosthetic heart valve thrombosis is a serious complication with an incidence of 1-6%. The reduction in active vitamin-K dependent protein C and S levels caused by warfarin treatment also results in a prothrombotic state. This study was conducted to investigate the connection between protein C (PC), protein S (PS), antithrombin III (ATIII) deficiency and prosthetic mechanical valve thrombosis. METHODS: Twenty-nine of the 283 patients who underwent valve replacement with St. Jude medical prosthesis had mechanical valve thrombosis (group 2). The rest were considered as group 1. Twelve of the 29 patients (41.4%) had isolated aortic valve replacement, 12 had isolated mitral valve replacement (41.4%) and 5 patients had double valve replacement (17.2%). Most of the patients had rheumatic valve disease at their 1st operation. The mean time of occurrence for mechanical valve occlusion was 4.1+/-1.0 years following surgery. RESULTS: The values of PC, PS and ATIII were obtained when the mechanical valves stuck or at routine follow-up. PC, PS and ATIII levels were significantly lower in the mechanical valve thrombosis group. PC levels were 75.4+/-37.6% and 49.9+/-32.2% in group 1 and 2, respectively (p=0.001). PC, PS and ATIII values were mostly lower in the 2nd group but this difference only became significant after at least 2 years of warfarin usage. CONCLUSIONS: Natural anticoagulant levels can be low during the use of warfarin. In which case the dose can be increased in order to hold the international normalized ratio (INR) at 3-3.5. However, more frequent follow-up is required and patients should be investigated for hypercoagulation states or deficiency in anticoagulant proteins. Patients referred to hospital with any mechanical valve thrombosis or recurrent thromboembolism should be evaluated for hypercoagulant proteins.
Asunto(s)
Antitrombina III/metabolismo , Prótesis Valvulares Cardíacas/efectos adversos , Proteína C/metabolismo , Proteína S/metabolismo , Trombosis/etiología , Adulto , Insuficiencia de la Válvula Aórtica/cirugía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Insuficiencia de la Válvula Mitral/cirugíaRESUMEN
BACKGROUND: The effect of Mg++SO4 on myocardial hemodynamics was investigated in this study. METHODS: Twelve dogs were entered in this research. Six dogs received Mg++SO4 and the remaining dogs were considered as controls. The amount of Mg++SO4 that was administered to the animals was 0.15 mmol/kg/hr each. The left anterior descending artery was occluded for a period of 1 hour and the drug was administered during reperfusion. RESULTS: Two hours after reperfusion, cardiac output was 1275+/-50 ml/min in the control group and 1475+/-25 ml/min in the Mg++SO4 group (p<0.05), pulmonary capillary wedge pressure was 18+/-3 mmHg in the control group and 12+/-2 mmHg in the Mg++SO4 group. CONCLUSIONS: In this study it was shown that Mg++SO4 usage after 1 hour arterial occlusion and 2 hours reperfusion protects the heart from the adverse effects of ischemia/reperfusion and had a better central hemodynamics.
Asunto(s)
Sulfato de Magnesio/uso terapéutico , Isquemia Miocárdica/tratamiento farmacológico , Daño por Reperfusión Miocárdica/tratamiento farmacológico , Animales , Gasto Cardíaco/efectos de los fármacos , Perros , Hemodinámica/efectos de los fármacos , Isquemia Miocárdica/fisiopatología , Daño por Reperfusión Miocárdica/fisiopatologíaRESUMEN
Plasma and urinary levels of 8-iso-PGF(2alpha) and 15-keto-dihydro-PGF(2alpha) were analysed at baseline and during the ischemia-reperfusion period in experimental spinal cord ischemia. A significant and immediate increase of 8-iso-PGF(2alpha) in plasma at the start and up to 60 min, and in the urine at 90-150 min following ischemia indicate an association of oxidative injury. The inflammatory response indicator 15-keto-dihydro-PGF(2alpha) in plasma increased significantly at the start and up to 60 min after ischemia. No such increase was seen in animals with no spinal cord ischemia. Thus, free radical mediated and cyclooxygenase catalysed products of arachidonic acid are increased during spinal cord ischemia as a consequence of oxidative injury and inflammation.
Asunto(s)
Dinoprost/análogos & derivados , Dinoprost/sangre , F2-Isoprostanos/metabolismo , Daño por Reperfusión/fisiopatología , Isquemia de la Médula Espinal/fisiopatología , Médula Espinal/fisiopatología , Animales , Aorta Torácica/cirugía , Biomarcadores , Líquido Cefalorraquídeo/química , F2-Isoprostanos/sangre , F2-Isoprostanos/orina , Radicales Libres/metabolismo , Inflamación/fisiopatología , Oxidación-Reducción , Daño por Reperfusión/metabolismo , Isquemia de la Médula Espinal/metabolismo , Porcinos , Factores de TiempoRESUMEN
This retrospective study was conducted to analyze a new concept of evaluation of the effect of distal runoff on patency in infrainguinal bypass surgery for arterial insufficiency. Distal runoff was evaluated on postreconstruction angiograms in 191 limbs undergoing femoropopliteal and femorodistal reconstruction. Runoff was characterized as good, fair, or poor. Determination of graft patency was made by clinical examination, ankle-brachial index measurement, or duplex scanning at 1 month and thereafter at 6-month intervals. Cumulative patency rates were calculated according to the actuarial life table method. Patency rates in limbs with good runoff were better than in limbs with fair and poor runoff; at 6 months, patency rates were 88.2%, 70.9%, and 21.8%, respectively (p < 0.01). Similar patency rates were found for good runoff in femoropopliteal and femorodistal reconstructions (84.7% in femoropopliteal and 75% in femorodistal reconstructions) at 6 months. The authors conclude that this method of angiographic evaluation accurately predicts patency in infrainguinal bypass reconstructions.
Asunto(s)
Vena Femoral/cirugía , Oclusión de Injerto Vascular/cirugía , Conducto Inguinal/irrigación sanguínea , Pierna/irrigación sanguínea , Vena Poplítea/cirugía , Grado de Desobstrucción Vascular/fisiología , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Procedimientos de Cirugía Plástica/mortalidad , Estudios Retrospectivos , Factores de Tiempo , Venas/trasplanteRESUMEN
OBJECTIVES: To investigate the effect of 100% oxygen ventilation on cerebrospinal fluid (CSF) oxygenation in 11 pigs during thoracic aortic cross-clamping. DESIGN: An aorto-aortic shunt was used for control of central hemodynamics and study of hypoperfusion by exsanguination. CSF PO2, PCO2 and pH were continuously monitored before and during clamping. The changes in hemodynamic parameters and intrathecal gas tensions in response to variations in proximal mean aortic pressure and fraction of inspired oxygen (FiO2) were recorded. RESULTS: Baseline CSF PO2 decreased from 4.8 +/- 1.9 to 2.6 +/- 2.2 kPa following aortic occlusion. Increasing FiO2 to 1.0 resulted in a significant increase in CSF PO2 to 4.1 +/- 3.0 with a return to 2.7 +/- 2.1 kPa after reducing FiO2 to 0.4 again. The same variations in FiO2 did not induce any significant changes in CSF PO2 during hypotension. CONCLUSION: Increased FiO2 during experimental thoracic aortic cross-clamping with stable proximal arterial pressure helps to maintain CSF PO2, whereas severe hypotension could not be compensated for by hyperoxemia.
Asunto(s)
Oxígeno/líquido cefalorraquídeo , Procedimientos Quirúrgicos Vasculares/métodos , Animales , Aorta Torácica , Constricción , Modelos Animales de Enfermedad , Femenino , Hemodinámica , Masculino , Porcinos , Procedimientos Quirúrgicos Vasculares/instrumentaciónRESUMEN
OBJECTIVE: We sought to study the effect of various modes of interruption of the spinal cord blood supply on intrathecal oxygenation. METHODS: In 24 pigs intrathecal PO (2), PCO (2), and pH were continuously monitored with a multiparameter catheter (Paratrend 7, Biomedical Sensors; Diametrics Medical, Inc, St Paul, Minn) during and after aortic crossclamping or selective interruption of segmental arteries and proximal collateral circulation. RESULTS: Proximal aortic clamping (n = 6) produced complete ischemia, whereas a second clamp close to the celiac trunk (n = 4) partly protected against spinal cord ischemia. This is explained by prevention of the steal phenomenon in the excluded part of the aorta. Adding clamps to the subclavian arteries (n = 6) created complete spinal ischemia as the collateral circulation was interrupted. In another group (n = 4) all segmental arteries below T5 were occluded with no reaction in the intrathecal variables. Additional selective clamping of supreme intercostal arteries (n = 4) showed the relative importance of the subclavian and vertebral collateral pathways. CONCLUSIONS: Continuous intrathecal PO (2) was monitored during various modes of interruption of the spinal cord blood supply. This provided insight into the ischemia mechanisms and relative importance of the segmental contribution and proximal collateral pathways of the spinal cord circulation in pigs. A short literature review is given, and aspects of comparative anatomy are discussed.
Asunto(s)
Oximetría/métodos , Oxígeno/análisis , Médula Espinal/irrigación sanguínea , Animales , Velocidad del Flujo Sanguíneo , Circulación Colateral , Femenino , Masculino , Médula Espinal/diagnóstico por imagen , Isquemia de la Médula Espinal/diagnóstico por imagen , Isquemia de la Médula Espinal/metabolismo , Isquemia de la Médula Espinal/fisiopatología , Isquemia de la Médula Espinal/prevención & control , Punción Espinal , Arteria Subclavia/anatomía & histología , Arteria Subclavia/diagnóstico por imagen , Porcinos , Ultrasonografía Doppler , Arteria Vertebral/anatomía & histología , Arteria Vertebral/diagnóstico por imagenRESUMEN
OBJECTIVE: To study the correlation between intrathecal PO2 and ultrastructural changes in the spinal cord during thoracic aortic occlusion in pigs. MATERIAL AND METHODS: In 18 pigs, online intrathecal oxygenation was monitored by a multiparameter Paratrend catheter (Biomedical Sensors, High Wycombe, United Kingdom) during 60 minutes' clamping of the proximal and distal descending thoracic aorta. The animals were randomly divided into 2 groups (A and B) depending on the level of distal aortic clamping. Distal aortic perfusion was restored through an aorto-iliac shunt, which also maintained low thoracic segmental perfusion of the spinal cord in group B. Perfusion-fixation technique was used before harvesting the spinal cord specimens, which later were evaluated with light and electron microscopy by an independent observer. Intrathecal parameters were interpreted as normal if PO2 was more than 0.8 kPa and PCO2 was less than 12 kPa, as intermediate ischemia if PO2 was 0.8 or less or PCO (2) was more than 12 kPa, and as absolute ischemia if PO2 was 0.8 or less and PCO2 was more than 12 kPa. RESULTS: Among 6 animals with ultrastructural changes of absolute spinal cord ischemia-reperfusion injury, 5 also had absolute ischemia according to variables derived by the Paratrend catheter. The 2 methods were in agreement in 3 of 5 animals with intermediate ischemia-reperfusion changes and in 5 of 6 animals with normal findings. The accuracy of cerebrospinal fluid PO2 and PCO2 to predict electron microscopy-verified intermediate or absolute ischemia-reperfusion injury was 94%. CONCLUSIONS: Monitoring of intrathecal PO2 after clamping of the descending aorta correlated with ultrastructural changes in the spinal cord in this pig model.
Asunto(s)
Oxígeno/líquido cefalorraquídeo , Daño por Reperfusión/patología , Médula Espinal/irrigación sanguínea , Animales , Biomarcadores/líquido cefalorraquídeo , Dióxido de Carbono/líquido cefalorraquídeo , Constricción , Femenino , Masculino , Microscopía Electrónica , Oximetría/métodos , Daño por Reperfusión/líquido cefalorraquídeo , Daño por Reperfusión/etiología , Sensibilidad y Especificidad , Médula Espinal/ultraestructura , PorcinosRESUMEN
BACKGROUND: The effect of ATP-MgCl2 on myocardial metabolism and hemodynamics was investigated in this study. METHODS: Twelve dogs were entered in this research. Six dogs received ATP-MgCl2 and the remaining dogs were considered as controls. The amount of ATP and MgCl2 concentration of this solution is 100 mumol/ml each. The volume administered to the animals during the aortic occlusion is 0.25 ml/kg/hour; in the solution are 100 mumol/ml dose each. The volume administered to the animals during reperfusion is 0.25 ml/kg/hour. The left anterior descending artery was occluded for a period of one hour and the drug was administered during reperfusion. RESULTS: Three hours after reperfusion, cardiac output was 1524 +/- 26 ml/min in the control group and 1638 +/- 47 ml/min in the ATP-MgCl2 group (p < 0.05), pulmonary capillary wedge pressure was 14 +/- 3 in the control group and 8 +/- 2 in the ATP-MgCl2 group. At the same time interval tissue ATP and lactate level was 7 +/- 3, 1.3 +/- 0.4 in the control group and 14 +/- 2, 0.0 +/- 0.2 in the ATP-MgCl2 group respectively (p < 0.05). CONCLUSIONS: In this study we demonstrated that ATP-MgCl2 usage after one hour of arterial occlusion protects the heart from the adverse effects of ischemia/reperfusion.
Asunto(s)
Adenosina Trifosfato/uso terapéutico , Isquemia Miocárdica/tratamiento farmacológico , Daño por Reperfusión Miocárdica/tratamiento farmacológico , Animales , Circulación Coronaria/efectos de los fármacos , Perros , Corazón/efectos de los fármacos , Hemodinámica/efectos de los fármacos , Miocardio/metabolismoRESUMEN
BACKGROUND: The most important factors that determine the outcome after femoropopliteal and femorodistal arterial reconstruction are still controversial. This report analysis the factors that determine the early and late patency of distal arterial reconstruction. PATIENTS AND METHODS: A retrospective analysis of patency after femorodistal arterial reconstruction with a new method for evaluation of angiographic runoff was performed for 336 arterial reconstructions. The different pre-, per- and postoperative risk factors were analysed in a Cox proportional hazards model. RESULT: The patency was significantly better for vein grafts in comparison to composite grafts and prosthetic grafts. It was 74% for vein, 46% for composite and 43% for prosthetic reconstructions, respectively, at 12 months after arterial reconstruction. The cumulative life table patency rate in extremities with good, intermediate and poor runoff was 62, 30 and 10%, respectively at 36 months. The patency rates for extremities operated on for claudication was significantly better than for extremities operated on for critical ischaemia. The multivariate analysis of different factors in a Cox analysis revealed that only the status of distal runoff, the graft material and the site of the distal anastomosis independently and significantly influenced the patency rates. CONCLUSIONS: A new model for evaluation of distal runoff proved to predict the patency rate of femoropopliteal and femorodistal arterial reconstructions reasonably well in this retrospective analysis.
Asunto(s)
Implantación de Prótesis Vascular , Oclusión de Injerto Vascular/etiología , Isquemia/cirugía , Pierna/irrigación sanguínea , Venas/trasplante , Anciano , Angiografía/métodos , Femenino , Arteria Femoral/cirugía , Oclusión de Injerto Vascular/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad , Arteria Poplítea/cirugía , Factores de RiesgoRESUMEN
BACKGROUND: The aim of the study was to evaluate the efficacy of iloprost on myocardial insufficiency associated with hypovolemic shock in dogs. We designed the study as a controlled randomized study. METHODS: Sixteen mixed-breed dogs were included into the study and divided into two equal groups as the control and iloprost groups. Mean arterial pressure was reduced to 45 mmHg by withdrawing the arterial blood into citrated bags. The control group did not receive any drug but the other group received iloprost at a rate of 20 ng/kg/min by an infusion pump. Iloprost infusion was started 30 min after the blood pressure was reduced to 45 mmHg. All measurements were made before removal of blood, 45 min after exsanguination and at 1 hour intervals for 3 hours. Left ventricular stroke work index was measured 72 hours after the study. The hemodynamic and biochemical parameters and blood gas analysis were obtained. RESULTS: After hemorrhage, cardiac index (CI) decreased significantly from 132 +/- 14 to 51 +/- 8 ml/kg/min in the control group and from 128 +/- 11 ml/kg/min to 47 +/- 13 ml/kg/min in the iloprost group, respectively but at the end of the third hour it was 81 +/- 8 ml/kg/min in the control group and 105 +/- 6 ml/kg/min in the iloprost group (p < 0.05). Tumor necrosis factor-alpha (TNF alpha) was 41 +/- 8 pg/ml in the control group and 18 +/- 6 in the iloprost group 3 hours after bleeding (p < 0.05). Tumor necrosis factor-alpha concentration was significantly higher in the control group than in the iloprost group. There was no significant difference in pH between the groups but actual bicarbonate concentrations were different between the groups (p < 0.05). At the end of the third hour total body oxygen consumption was 105 +/- 11 ml/min in the control group and 132 +/- 12 ml/min in the iloprost group (p < 0.05). Oxygen delivery 3 hours after hemorrhage was 201 +/- 19 ml/min in the control group and 252 +/- 24 ml/min in the iloprost group (p > 0.05). Left ventricular stroke work index was higher in the iloprost group (p < 0.05). CONCLUSIONS: Hemorrhagic shock causes tumor necrosis factor-alpha release which may lead to multiple organ failure. Organ dysfunction still persists even after the appropriate treatment. Iloprost attenuates the release of tumor necrosis factor-alpha which may improve the adverse effects of hemorrhagic shock.
Asunto(s)
Iloprost/uso terapéutico , Inhibidores de Agregación Plaquetaria/uso terapéutico , Choque Hemorrágico/tratamiento farmacológico , Vasodilatadores/uso terapéutico , Animales , Perros , Choque Hemorrágico/fisiopatologíaRESUMEN
BACKGROUND: Between 1986 and 1996, 194 patients underwent isolated aortic valve replacement with 21-23 no. St. Jude Medical mechanical heart valves (small sized group) and 163 patients with 27-29 no. (large sized group). METHODS: The mean age at operation was 45.04+/-15.90 years (range: 12-76 years) for the small sized group and 38.05+/-13.41 years (range: 16-68 years) for the large sized group. Preoperatively, 39.7% of the patients from the small sized group and 42.9% from the large sized group had pure aortic stenosis, 31.9% and 27.6% had pure aortic insufficiency. Most of the patients had rheumatic valve disease. RESULTS: The overall hospital mortality rate was 12.4% and 3.07% respectively in the small sized and large sized groups (p<0.001). The overall actuarial survival rate for 10 years was 95.33+/-2.73% and 93.06+/-3.98% respectively in the small sized group and large sized group (p>0.05). In the small sized group male sex and all complications, in large sized group age and all complications were the statistically important hospital mortality predictors (p<0.05). CONCLUSIONS: Although, operative mortality and long term morbidity were higher in the small sized group, these changes did not reflect the actuarial survivals between the groups. Small sized valves carry some risk, but these risks do not affect long-term survival.
Asunto(s)
Válvula Aórtica/cirugía , Prótesis Valvulares Cardíacas , Adolescente , Adulto , Anciano , Insuficiencia de la Válvula Aórtica/mortalidad , Insuficiencia de la Válvula Aórtica/cirugía , Estenosis de la Válvula Aórtica/mortalidad , Estenosis de la Válvula Aórtica/cirugía , Niño , Femenino , Mortalidad Hospitalaria , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/mortalidad , Diseño de Prótesis , Reoperación , Cardiopatía Reumática/mortalidad , Cardiopatía Reumática/cirugía , Tasa de SupervivenciaRESUMEN
BACKGROUND: Surgical procedures on the thoracoabdominal part of the aorta make the spinal cord vulnerable to ischemia. Paraplegia is the most severe complication following thoracoabdominal operations. In this study, iloprost was used as an agent to decrease the severity of ischemia and reperfusion injury to the spinal cord during aortic occlusion and declamping. METHODS: Twelve adult mongrel dogs weighing 17+/-2 kg were used in this study. The animals were randomly assigned to either group I, which received saline solution (6 dogs), or group II, which received prostacyclin. Group I was referred to as the control group and group II as the iloprost group. After baseline measurements were completed, the aorta was cross-clamped for sixty minutes distal to the left subclavian artery. No pharmacologic agents were used to control blood pressure in group I. Proximal and distal mean arterial pressures (DMAP) were monitored continuously. DMAP were considered as diastolic pressure in preocclusion and reperfusion periods. Iloprost administration was started at a rate of 5 ng/kg/minute five minutes before the aortic occlusion. This dosage was increased to 25 ng/kg/minute during aortic occlusion. RESULTS: Mean proximal arterial pressure was 147+/-12 mmHg in the control group and 116+/-13 mmHg in the iloprost group at occlusion (p<0.01). Mean distal arterial pressure was 19+/-7 in the control group and 37+/-5 in the iloprost group during clamping (p<0.05). Functional outcome was evaluated according to Tarlov scores 24 hours after the study. Although none of the animals recovered completely from the control group, 4 animals from the iloprost group recovered (p<0.05). Following the neurologic assessment, animals were sacrificed and specimens were taken for the electron microscopic study. Electron microscopic changes documented that severe mitochondrial damage and vacuolisation occurred in the control group. However these changes were more subtle in the iloprost group. CONCLUSIONS: As a result of this study we concluded that iloprost infused before and during clamping of the thoracic aorta mitigates the spinal cord injury due to ischemia and reperfusion following unclamping.
Asunto(s)
Aorta Abdominal/cirugía , Iloprost/farmacología , Isquemia/prevención & control , Médula Espinal/irrigación sanguínea , Vasodilatadores/farmacología , Animales , Presión Sanguínea/fisiología , Perros , Relación Dosis-Respuesta a Droga , Isquemia/patología , Isquemia/fisiopatología , Microscopía Electrónica , Vaina de Mielina/patología , Daño por Reperfusión/patología , Daño por Reperfusión/fisiopatología , Daño por Reperfusión/prevención & control , Médula Espinal/patologíaRESUMEN
OBJECTIVES: to evaluate the efficacy of single-dose pre-insertion gamma radiation of vein grafts in the prevention of intimal hyperplasia. METHODS: femoral artery interposition grafts with internal jugular vein were inserted in 12 mongrel dogs. The animals were randomly divided into two groups. Immediately before graft replacement, jugular veins were treated with a single dose of cobalt-60 radiation at 14 Gy or received no radiation (control group). Six weeks after graft insertion, the vein grafts were pressure-perfusion fixed and harvested for the histomorphometric analysis. Quantitative data on anastomotic stenosis were calculated from Gilman parameters after cross-sectional image analysis. RESULTS: vein grafts treated with radiation demonstrated significantly decreased neointima formation compared with grafts in the control group. The mean Gilman parameter for the control group was 1.09 S.E.M. 0.34 mm and for the radiotherapy group was 0.65 S.E. M. 0.23 mm (p<0.05). All vein grafts in the radiotherapy group had a decreased amount of intimal and cellular infiltration. CONCLUSION: single-dose external pre-insertion gamma radiation of vein grafts reduced the amount of intimal hyperplasia in this animal model.