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1.
Ecol Appl ; 32(8): e2707, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-35808937

RESUMEN

Arthropod biomass is a key element in ecosystem functionality and a basic food item for many species. It must be estimated through traditional costly field sampling, normally at just a few sampling points. Arthropod biomass and plant productivity should be narrowly related because a large majority of arthropods are herbivorous, and others depend on these. Quantifying plant productivity with satellite or aerial vehicle imagery is an easy and fast procedure already tested and implemented in agriculture and field ecology. However, the capability of satellite or aerial vehicle imagery for quantifying arthropod biomass and its relationship with plant productivity has been scarcely addressed. Here, we used unmanned aerial vehicle (UAV) and satellite Sentinel-2 (S2) imagery to establish a relationship between plant productivity and arthropod biomass estimated through ground-truth field sampling in shrub steppes. We UAV-sampled seven plots of 47.6-72.3 ha at a 4-cm pixel resolution, subsequently downscaling spatial resolution to 50 cm resolution. In parallel, we used S2 imagery from the same and other dates and locations at 10-m spatial resolution. We related several vegetation indices (VIs) with arthropod biomass (epigeous, coprophagous, and four functional consumer groups: predatory, detritivore, phytophagous, and diverse) estimated at 41-48 sampling stations for UAV flying plots and in 67-79 sampling stations for S2. VIs derived from UAV were consistently and positively related to all arthropod biomass groups. Three out of seven and six out of seven S2-derived VIs were positively related to epigeous and coprophagous arthropod biomass, respectively. The blue normalized difference VI (BNDVI) and enhanced normalized difference VI (ENDVI) showed consistent and positive relationships with arthropod biomass, regardless of the arthropod group or spatial resolution. Our results showed that UAV and S2-VI imagery data may be viable and cost-efficient alternatives for quantifying arthropod biomass at large scales in shrub steppes. The relationship between VI and arthropod biomass is probably habitat-dependent, so future research should address this relationship and include several habitats to validate VIs as proxies of arthropod biomass.


Asunto(s)
Artrópodos , Animales , Biomasa , Ecosistema , Pradera , Dispositivos Aéreos No Tripulados , Plantas
2.
Int J Sports Med ; 35(14): 1170-8, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25210791

RESUMEN

We examined the heart rate (HR)-based intensity profile during an ultra-endurance triathlon (UET) estimated from the individual HR-oxygen uptake (˙VO2) relationship during specific graded tests, relating it to race performance. 9 male ultra-endurance triathletes completed the study. Before racing, subjects performed graded exercise tests involving cycle (C) ergometry, treadmill running (R) and free swimming (S) for peak ˙VO2 and HR at ventilatory thresholds (VT). Exercise-specific HR-˙VO2 regression equations were developed. Mean race HR was higher during S (149.2 (10.1) bpm) than during C (137.1 (5.7) bpm) and R (136.2 (10.5) bpm). During C and R, HR was below both VT (11% and 27-28%). HR differences between S and C correlated with C, R and final times. The greatest differences between S and C were related to the worst times in the next stages. These ultra-endurance triathletes performed S at a higher relative intensity, which was inversely correlated with performance in the following stages. The best predictors of final racing time (81%) were weight-adjusted ˙VO2max and HR difference between C and S. A more adequate characterization of the time pattern during the whole race, especially during S, adds new information concerning the intensity profile and cardiovascular demands of an UET race.


Asunto(s)
Ciclismo/fisiología , Frecuencia Cardíaca/fisiología , Consumo de Oxígeno/fisiología , Resistencia Física/fisiología , Carrera/fisiología , Natación/fisiología , Adulto , Prueba de Esfuerzo , Humanos , Masculino , Fenómenos Fisiológicos Respiratorios
3.
Int J Sports Med ; 35(5): 403-11, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24081620

RESUMEN

This study examined the relationship between ratings of perceived exertion (RPE, CR-10), heart rate (HR), peak blood lactate (La peak), and immersion (IM) parameters in 17 elite synchronized swimmers performing 30 solo and duet routines during competition. All were video recorded (50 Hz) and an observational instrument was used to time the IM phases. Differences in the measured variables were tested using a linear mixed-effects model. RPE was 7.7 ± 1.1 and did not differ among routines, and neither did any of the HR parameters. There were differences among routines in La peak (F3,7=16.5; P=0.002), number of IM (F3,15=14.0; P<0.001), total time immersed (F3,16=26.6; P<0.001), percentage of time immersed (F3,13=6.5; P=0.007) and number of IM longer than 10 s (F3,19=3.0; P=0.04). RPE correlated positively to HR pre-activation, range of variation and recovery, IM parameters and La peak, and inversely to minimum and mean HR. A hierarchical multiple linear regression (MLR) model (number of IM >10 s, HR recovery, minimum HR, and La peak) explained 62% RPE variance (adj. Rm 2=0.62; P<0.001). A stepwise MLR model (La peak, mean IM time and pre-exercise HR) explained 46% of performance variance (adj. Rm 2=0.46; P<0.001). Findings highlight the psycho-physical stress imposed by the combination of intense dynamic exercise with repeated and prolonged apnea intervals during SS events.


Asunto(s)
Contencion de la Respiración , Frecuencia Cardíaca/fisiología , Percepción , Esfuerzo Físico/fisiología , Natación/fisiología , Adolescente , Adulto , Humanos , Ácido Láctico/sangre , Monitoreo Ambulatorio , Consumo de Oxígeno/fisiología , Factores de Tiempo , Grabación en Video , Adulto Joven
4.
Ultrasound Obstet Gynecol ; 38(1): 44-51, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21465603

RESUMEN

OBJECTIVES: To assess the diagnostic power of a new cervical consistency index (CCI) obtained using transvaginal sonography for the prediction of spontaneous preterm birth (PTB) and to establish reference ranges for this new variable. METHODS: Included in this prospective cross-sectional study were 1115 singleton pregnancies at 5-36 weeks of gestation. Anteroposterior cervical diameter was measured before (AP) and after (AP') application of pressure on the cervix using the transvaginal probe. The index was calculated using the formula: CCI=((AP'/AP) × 100). Cervical length was also measured. The outcomes evaluated were spontaneous PTB before 32, 34 and 37 weeks. Logistic regression and analysis of receiver-operating characteristics (ROC) curves were performed to evaluate the diagnostic power of CCI and cervical length (adjusted for gestational age). Intraclass correlation coefficients (ICCs) and Bland-Altman analysis were used to evaluate intra- and interobserver variability. RESULTS: In the 1031 women with follow-up, the rate of spontaneous PTB before 32 weeks was 0.87%, before 34 weeks was 2.13% and before 37 weeks was 7.76% (n=80). There were 31 (3.01%) iatrogenic PTBs before 37 weeks. An inverse linear correlation between gestational age and CCI was observed, with regression equation: CCI (in %)=89.8 - 1.35 × (GA in weeks); r(2)=0.66, P<0.001. Cervical length showed an inverse quadratic, though non-significant, relationship with gestational age: CL (in mm)=31.084 - 0.0278× (GA in weeks)(2) + 1.0772× (GA in weeks); r(2)=0.076, P<0.14. The intra- and interobserver ICCs for CCI were 0.99 (95% CI, 0.988-0.994) and 0.98 (95% CI, 0.973-0.987), respectively. The area under the ROC curve for CCI in the prediction of spontaneous PTB before 32 weeks was 0.947, for spontaneous PTB before 34 weeks it was 0.943 and for spontaneous PTB before 37 weeks it was 0.907. For a 5% screen-positive rate, CCI had a sensitivity of 67%, 64% and 45% for prediction of spontaneous PTB before 32, 34 and 37 weeks, respectively, with equivalent values of 11%, 9% and 11% for cervical length. CONCLUSIONS: CCI shows a clear inverse linear relationship with GA. Assessment of CCI is reproducible and is effective in the prediction of spontaneous PTB. This new variable appears to provide better prediction of spontaneous PTB than does cervical length.


Asunto(s)
Cuello del Útero/diagnóstico por imagen , Nacimiento Prematuro/diagnóstico por imagen , Adulto , Cuello del Útero/anomalías , Estudios de Cohortes , Femenino , Edad Gestacional , Humanos , Recién Nacido , Recien Nacido Prematuro , Valor Predictivo de las Pruebas , Embarazo , Nacimiento Prematuro/clasificación , Estudios Prospectivos , Valores de Referencia , Ultrasonografía , Adulto Joven
6.
Rev. esp. cardiol. (Ed. impr.) ; 75(3): 203-212, mar. 2022. ilus, tab, graf
Artículo en Español | IBECS (España) | ID: ibc-206977

RESUMEN

Introducción y objetivos: La posición final de las neocomisuras en el implante percutáneo de válvula aórtica (TAVI) es aleatoria, lo que podría dificultar el acceso coronario y procedimientos futuros. Nuestro objetivo es desarrollar un método estandarizado para conseguir el alineamiento de las comisuras con ACURATE neo. Métodos: La relación entre las comisuras nativas y las neocomisuras de la válvula se analizó en 11 pacientes con estenosis aórtica grave sometidos a TAVI. Con base en la tomografía computarizada, se desarrolló un modelo in silico para predecir la posición final de los postes comisurales. A continuación, se desarrolló una técnica modificada de implante con alineamiento comisural adecuado (ACA) y un dispositivo específico para orientar el sistema de liberación. Por último, el implante de TAVI con alineamiento comisural se simuló en modelos impresos en 3D e in vivo. Se analizó el grado de mal alineamiento y de solapamiento coronario (SC). Resultados: El modelo in silico predijo con precisión la posición de los postes comisurales tanto para implantes convencionales (2) como aquellos con técnica de ACA (9) (coeficiente de correlación=0,994; IC95%, 0,989-0,998; p <0,001). El TAVI con una rotación del sistema específica para cada paciente se simuló con éxito en biomodelos y en 9 pacientes (mal alineamiento comisural medio in vivo, 7,7±3,9°). Ninguno de los implantes con técnica ACA presentó SC, mientras que la simulación in silico para los mismos casos pero mediante implante convencional predijo SC en 6 de los 9 casos. Conclusiones: El alineamiento comisural preciso del dispositivo ACURATE neo es factible mediante la inserción del sistema de liberación rotado específicamente para cada paciente basándose en el análisis de la tomografía computarizada. Este método sencillo y reproducible de alineamiento comisural podría utilizarse con todo tipo de dispositivos para TAVI (AU)


Introduction and objectives: Final position of the neo-commissures is uncontrolled during transcatheter aortic valve implantation (TAVI), potentially hindering coronary access and future procedures. We aimed to develop a standard method to achieve commissural alignment with the ACURATE neo valve. Methods: The relationship between native and TAVI neo-commissures was analyzed in 11 severe aortic stenosis patients undergoing TAVI. Based on computed tomography analysis, an in silico model was developed to predict final TAVI commissural posts position. A modified implantation technique, accurate commissural alignment (ACA) and a dedicated delivery system were developed. TAVI implants were tested in 3-dimensional (3D) printed models and in vivo. Commissural misalignment and coronary overlap (CO) were analyzed. Results: The in silico model accurately predicted final position of commissural posts irrespective of the implantation technique performed (correlation coefficient, 0.994; 95%CI, 0.989-0.998; P<.001). TAVI implant with patient-specific rotation was simulated in 3D printed models and in 9 patients. ACA-oriented TAVI implants presented adequate commissural alignment in vivo (mean commissural misalignment of 7.7 ±3.9°). None of the ACA oriented implants showed CO, whereas in silico conventional implants predicted CO in 6 of the 9 cases. Conclusions: Accurate commissural alignment of the ACURATE neo device is feasible by inserting the delivery system with a patient-specific rotation based on computed tomography analysis. This is a simple and reproducible method for commissural alignment that can be potentially used for all kinds of TAVI devices (AU)


Asunto(s)
Humanos , Reemplazo de la Válvula Aórtica Transcatéter , Estenosis de la Válvula Aórtica/terapia , Tomografía Computarizada por Rayos X , Índice de Severidad de la Enfermedad , Pronóstico
7.
Nat Prod Res ; 19(7): 719-22, 2005 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16076643

RESUMEN

Four diterpene alcohols were isolated from the neutral hexane extract of the cones of Cedrus atlantica, and their structures were confirmed after comparing their spectral data with literature values. These products exhibited significant antibacterial activity against gram (+/-) bacteria.


Asunto(s)
Cedrus/química , Diterpenos/aislamiento & purificación , Diterpenos/farmacología , Bacterias Grampositivas/efectos de los fármacos , Alcoholes/aislamiento & purificación , Alcoholes/farmacología , Pruebas de Sensibilidad Microbiana
8.
J Am Soc Mass Spectrom ; 15(2): 253-9, 2004 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-14766292

RESUMEN

Water solutions with electrical conductivities ranging from that of the deionized water up to 2 S/m have been electrosprayed in air through narrow silica tubes. Results show unambiguously that steady cone jets of water in air without the assistance of glow discharge can be formed for the range of electrical conductivities we have explored. The absence of corona discharge has been proven not only for the good agreement between the experimental results and the scaling laws given in the cone-jet literature but also for the independence of the spray current on the atmosphere (air or CO(2)) in which water was being electrosprayed. Other regimes such as the electric dripping and the assisted glow discharge cone-jet mode that appear in the electrospraying of water in air at room temperature have also been investigated.

9.
Org Lett ; 3(5): 647-50, 2001 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-11259027

RESUMEN

[structure: see text]. The tetracyclic ketal 24, a suitable intermediate for the synthesis of antitumor pentacyclic quassinoids, has been efficiently prepared from communic acids (5a-c), via methyl ketone 9. The synthetic sequence from 9 to 24 consists of 15 steps in 12% overall yield.


Asunto(s)
Antineoplásicos Fitogénicos/síntesis química , Diterpenos/síntesis química , Cuassinas , Plantas Medicinales/química , Terpenos
10.
Phytochemistry ; 54(1): 23-7, 2000 May.
Artículo en Inglés | MEDLINE | ID: mdl-10846742

RESUMEN

Incubation of a communic acid-derived synthon with Cunninghamella elegans quantitatively affords 1 beta, 3 beta- and 7 beta- monohydroxylated derivatives.


Asunto(s)
Hongos/metabolismo , Lactonas/metabolismo , Terpenos/metabolismo , Cunninghamella/química , Cunninghamella/metabolismo , Hongos/química , Hidroxilación , Lactonas/química , Espectroscopía de Resonancia Magnética , Terpenos/química
11.
Phytochemistry ; 54(8): 741-5, 2000 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11014258

RESUMEN

Two new saikosaponins have been identified in the butanolic fraction of the ethanol extract of the roots of Bupleurum spinosum: 3beta,16alpha,23,28-tetrahydroxyoleana-11,13(18)-dien- 30-oic acid 3-O-beta-D-glucopyranosyl-(1 --> 2)-beta-D-glucopyranosyl-(1 --> 3)-beta-D-fucopyranoside, and 3beta,16alpha,23,28,30-pentahydroxyoleana-11,13(18)-diene 3-O-beta-D-glucopyranosyl-(1 --> 2)-beta-D-glucopyranosyl-(1 --> 3)-beta-D-fucopyranoside. 3Beta,16beta,23-trihydroxy-13,28-epoxyolean-11-ene 3-O-beta-D-glucopyranosyl-(1 --> 2)-beta-D-glucopyranosyl-(1 --> 3)-beta-D-fucopyranoside was also isolated, and this structure agreed with the one proposed for bupleuroside I, but their spectroscopic data have not been described until now. From the same fraction of the roots of Bupleurum gibraltaricum, the known compound buddlejasaponin IV has been isolated as the predominant component (90%). Structures were elucidated using spectroscopic analysis, specially 2D-NMR experiments.


Asunto(s)
Magnoliopsida/química , Raíces de Plantas/química , Saponinas/aislamiento & purificación , Estructura Molecular , Saponinas/química , Análisis Espectral
12.
Phytochemistry ; 51(4): 529-41, 1999 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10389267

RESUMEN

The hexane extract of aerial parts of Santolina rosmarinifolia subsp. canescens afforded eight new sesquiterpenes in addition to known compounds. Their structures were determined by spectroscopic methods and chemical transformations. The conformational analysis of the germacrane constituents was carried out by spectroscopic methods, including NMR at varying temperature and by molecular mechanics calculations. The antifeedant, antibacterial and antitumoral activity of selected compounds has been tested.


Asunto(s)
Asteraceae/química , Sesquiterpenos/química , Animales , Antiinfecciosos/química , Antiinfecciosos/aislamiento & purificación , Antiinfecciosos/farmacología , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/aislamiento & purificación , Antineoplásicos Fitogénicos/farmacología , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Ratones , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Sesquiterpenos/aislamiento & purificación , Sesquiterpenos/farmacología , Células Tumorales Cultivadas
13.
Int J Cardiol ; 49(3): 284-6, 1995 May.
Artículo en Inglés | MEDLINE | ID: mdl-7649678

RESUMEN

Coronary angioplasty of an anomalous coronary artery can be technically challenging because of difficulty in cannulating the aberrant vessel and in obtaining a stable guiding catheter position. Only three cases with the right coronary artery originating from the left sinus of Valsalva were previously reported. We present a new case in which a successful angioplasty was obtained using a Williams LR guiding catheter.


Asunto(s)
Angioplastia Coronaria con Balón , Anomalías de los Vasos Coronarios/terapia , Seno Aórtico/anomalías , Angioplastia Coronaria con Balón/instrumentación , Cateterismo Cardíaco/instrumentación , Cateterismo Cardíaco/métodos , Femenino , Humanos , Persona de Mediana Edad
14.
J Agric Food Chem ; 48(7): 3003-7, 2000 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10898656

RESUMEN

A collection of 11 natural and synthetic podolactones have been tested as allelochemicals in a range between 10(-4) and 10(-9) M, and their potential use as natural herbicide models is discussed. Their effects on the germination and growth of the dicots Lactuca sativa (cv. Nigra and cv. Roman), Lepidium sativum, and Lycopersicon esculentum and the monocots Allium cepa, Hordeum vulgare, and Triticum aestivum as standard target species have been studied. An important inhibitory effect on the germination and growth of all tested species (average = 90%) was produced by compounds 9-11 at 10(-4) M. The specific structural requirements related to their activities are studied. On the basis of these results, their use as potential natural herbicide models is proposed.


Asunto(s)
Insecticidas/química , Terpenos/química , Herbicidas/farmacología , Insecticidas/farmacología , Modelos Químicos , Plantas/efectos de los fármacos , Relación Estructura-Actividad , Compuestos de Sulfonilurea/farmacología , Terpenos/farmacología
15.
Phys Rev E Stat Nonlin Soft Matter Phys ; 66(3 Pt 2B): 036311, 2002 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-12366257

RESUMEN

The mechanism of appearance of swirl in a certain class of converging flows is investigated numerically. The analysis is motivated by the spontaneous generation of swirl, which has been observed in electrified menisci (Taylor cones). The electrical stress acting on the cone surface drives these electrified millimetric fluid flows. Numerical results show that the primarily swirl-free meridian flow is unstable within an interval of values of the Reynolds number based on the surface stress. For values of the Reynolds number outside this interval, which depends on the forcing conditions and the geometry of the flow, the nonswirling meridian flow is stable. The instability mechanism of circulation amplification, which has nothing to do with the well-known increase of swirl velocity due to the vortex stretching mechanism, is due to a convection-diffusion effect. The circulation accumulated at the axis zone by the converging meridian motion is pumped by diffusion toward the conical surface. This feedback loop mechanism shoots the circulation amplification for values of the Reynolds number larger than a critical one. The same instability mechanism of swirl amplification could also appear in other converging flows generated by body forces (natural convection, electrical forces, etc.).

16.
Clin Cardiol ; 19(8): 631-6, 1996 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-8864336

RESUMEN

HYPOTHESIS: The study was undertaken to characterize acute myocardial infarction (AMI) in young patients. METHODS: In all 108 consecutive Mediterranean patients with AMI (102 men and 6 women), aged < or = 40 years, were prospectively included in this study over a period of 6.5 years. Coronary angiography was carried out within the first month and data from these patients with normal or diseased coronary arteries were compared. Clinical features, risk factors, and in-hospital and late morbidity and mortality were evaluated. RESULTS: Young patients with AMI represent 4.1% of the 2,644 patients admitted because of definite AMI during this period. The most common risk factors were cigarette smoking (94.5%) and hypercholesterolemia (48%). Location of the AMI was anterior in 37%, inferior in 57.5%, and non-Q in 5.5%. A history of previous angina was present in 42.5% of the patients, including all seven patients with previous myocardial infarction (6.5%). However, in 52% of the patients the anginal episodes started in the week prior to the AMI. In-hospital mortality and mortality during a mean follow-up of 41 +/- 23 months were 3.7 and 3.8%, respectively. The Kaplan-Meier actuarial curve assessed on 97 of 104 survivors was 100 and 94% at 1 and 5 years, respectively. Coronary arteries were angiographically normal in 17 (20%) of 87 survivors. Compared with young patients who had obstructive lesions, this subset had a lower age and fewer risk factors, reinfarction (p < 0.05), and late angina (p < 0.01), but development of congestive heart failure and survival were similar in both groups. CONCLUSION: These data suggest that young patients with AMI are very frequently heavy smokers, have a high incidence of angiographically normal coronary arteries, and that the short- and long-term prognosis is excellent.


Asunto(s)
Infarto del Miocardio/epidemiología , Adulto , Factores de Edad , Angiografía Coronaria , Femenino , Humanos , Incidencia , Masculino , Infarto del Miocardio/diagnóstico por imagen , Infarto del Miocardio/mortalidad , Estudios Prospectivos , Factores de Riesgo , España , Análisis de Supervivencia
17.
IEEE Trans Pattern Anal Mach Intell ; 3(2): 204-6, 1981 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21868937

RESUMEN

The equivalence of nonterminals of an expansive tree grammar is considered. Algorithms are presented for constructing sets of equivalent nonterminals for an expansive tree grammar, for reducing the grammar, and for determining whether two grammars generate the same language.

18.
J Colloid Interface Sci ; 272(1): 104-8, 2004 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-14985028

RESUMEN

This study shows that conducting liquids can be electrosprayed in steady cone-jet mode inside liquid insulator baths. Experimental results show that the current emitted from the meniscus fits well the scaling laws given in the literature for electrosprays in air at atmospheric pressure or vacuum. The technique may be of interest in obtaining fine liquid-liquid emulsions of uniformly sized droplets in the nanometric range.

19.
Rev Esp Cardiol ; 48(1): 70-1, 1995 Jan.
Artículo en Español | MEDLINE | ID: mdl-7878286

RESUMEN

The development of aneurysm at the Blalock-Taussig shunt, dilated two years before is described. It is rounded with a diameter of 19 mm. and located at the junction of the right subclavian artery and the right pulmonary artery, that is, at the site of previous balloon dilatation. We think that the pathogenesis is the same as that of the aortic aneurysms which develop after the balloon catheter dilation at the same level. The actual prognosis is unknown being an undescribed pathology.


Asunto(s)
Aneurisma/etiología , Cateterismo , Arteria Pulmonar , Arteria Subclavia , Aneurisma/diagnóstico , Niño , Femenino , Cardiopatías Congénitas/complicaciones , Cardiopatías Congénitas/terapia , Humanos , Politetrafluoroetileno , Atresia Pulmonar/complicaciones , Atresia Pulmonar/terapia , Factores de Tiempo
20.
Rev Esp Cardiol ; 50(1): 42-7, 1997 Jan.
Artículo en Español | MEDLINE | ID: mdl-9053946

RESUMEN

BACKGROUND: Surgical correction in infants born with transposition of the great arteries, venous rerouting procedure (Mustard or Senning operation) or an arterial switch operation, can be complicated by vascular narrowings. Balloon dilatation angioplasty may be the treatment for these stenotic lesions and is attempted to avoid a reoperation of these patients. MATERIAL AND METHODS: Angioplasty was attempted in nine patients after the surgical correction of transposition of the great arteries. Senning procedure was performed in sixty-one patients; two patients (3.2%) were successfully balloon-dilated for systemic venous obstruction: superior vena caval obstruction (case 1) and inferior vena caval obstruction (case 2). Arterial switch operation was performed in forty patients, balloon angioplasty was attempted in seven patients (17.5%) who developed supravalvar pulmonary artery stenosis. Mean age at dilation was 32.5 +/- 20.7 months (range 11 to 67) in the switch arterial group. Age at dilation in the Senning group was 8 and 106 months. The balloon/stenosis diameter was 2 to 3 in the switch arterial operation and 3 to 8 in the Senning procedure. RESULTS: Balloon dilatation angioplasty was successful in three patients with supravalvar pulmonary stenosis postarterial switch operation (mean age was 16.6 months) and reduced the peak-to-peak gradient from 78.6 +/- 36.6 mmHg to 44 +/- 15 mmHg. There was no success after angioplasty in three patients and it was not possible to cross the stenosis with the guidewire in one (mean age was 46 months). Balloon dilatation angioplasty was successful in the obstruction following Senning procedure. CONCLUSIONS: These data indicate that although the success rate of balloon angioplasty for supravalvar pulmonary stenosis after the arterial switch operation is low, balloon angioplasty can be the first therapeutic choice owing to its low complication rate and the potential benefit of the procedure. The success rate should be higher if angioplasty is performed at a younger age after operating and a balloon of adequate size is used. Postoperative systemic venous obstructions can be successfully managed with balloon dilatation.


Asunto(s)
Cateterismo , Estenosis de la Válvula Pulmonar/terapia , Transposición de los Grandes Vasos/cirugía , Preescolar , Terapia Combinada , Femenino , Humanos , Lactante , Masculino
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