Determining Haemodynamic Wall Shear Stress in the Rabbit Aorta In Vivo Using Contrast-Enhanced Ultrasound Image Velocimetry.

Abnormal blood flow and wall shear stress (WSS) can cause and be caused by cardiovascular disease. To date, however, no standard method has been established for mapping WSS in vivo. Here we demonstrate wide-field assessment of WSS in the rabbit abdominal aorta using contrast-enhanced ultrasound image velocimetry (UIV). Flow and WSS measurements were made independent of beam angle, curvature or branching. Measurements were validated in an in silico model of the rabbit thoracic aorta with moving walls and pulsatile flow. Mean errors over a cardiac cycle for velocity and WSS were 0.34 and 1.69%, respectively. In vivo time average WSS in a straight segment of the suprarenal aorta correlated highly with simulations (PC = 0.99) with a mean deviation of 0.29 Pa or 5.16%. To assess fundamental plausibility of the measurement, UIV WSS was compared to an analytic approximation derived from the Poiseuille equation; the discrepancy was 17%. Mapping of WSS was also demonstrated in regions of arterial branching. High time average WSS (TAWSSxz = 3.4 Pa) and oscillatory flow (OSIxz = 0.3) were observed near the origin of conduit arteries. In conclusion, we have demonstrated that contrast-enhanced UIV is capable of measuring spatiotemporal variation in flow velocity, arterial wall location and hence WSS in vivo with high accuracy over a large field of view.

Gastrointestinal hemodynamic changes during therapeutic hypothermia and after rewarming in neonatal hypoxic-Ischemic encephalopathy.

BACKGROUND: Hypoxic-ischemic encephalopathy (HIE) is associated with disturbances in visceral blood flow velocities. Therapeutic Hypothermia (TH) is a standard of care; however, its impact on gastrointestinal blood flow in infants with HIE is unknown. The objective of this study was to assess gastrointestinal (GI) blood flow and left ventricle output (LVO) in infants with hypoxic-ischemic encephalopathy during whole body TH and after rewarming. METHODS: Serial echocardiography and Doppler evaluation of intestinal blood flow (celiac (CA) and superior mesenteric (SMA) arteries) were prospectively performed in a cohort of 20 newborn infants with HIE at 4 time points during hypothermia and after rewarming. Demographic, clinical and biochemical data were collected and analyzed for their relevance. RESULTS: Median gestational age and birth weight was 40 weeks (37-41) and 3410 g (2190-4950) respectively. Celiac and mesenteric artery flow remained low during hypothermia and rose significantly after rewarming [peak systolic velocity in CA (0.63 m/s to 0.77 m/s, p = 0.004) and SMA (0.43 m/s to 0.55 m/s, p = 0.001)]. This increase was temporally associated with increased left ventricular output (106 ml/kg/min to 149 ml/kg/min, p < 0.0001). Median age to reach 25% of the feeds was 5 days (1-7 days). All patients survived. CONCLUSIONS: CA and SMA blood flow velocity and LVO did not vary during hypothermia but rose after rewarming. This may suggest protective effect of therapeutic hypothermia on gastrointestinal system. The association of these physiological changes with neonatal outcome needs further assessment.

The early postnatal blood flow characteristics in the superior mesenteric and coeliac arteries in late preterm neonates.

OBJECTIVES: The objective of this study is to evaluate intestinal blood flow changes within the first 72 h in the late preterm infants in comparison with the healthy term neonates. METHODS: In this prospective study, we analyzed Doppler flow velocity waveforms of superior mesenteric artery (SMA) and coeliac trunc (TC) in 20 late preterm and 20 term infants at the age of 2, 24, and 72 h. RESULTS: Significant end-diastolic velocity (end-diastolic velocity (EDV)SMA) rise up to 24 h was documented in all patients (late preterm: -9.32 ± 9.48 to 17.01 ± 6.94; p < .05; term: -8 ± 5.74 to 12.39 ± 3.33; p < .001), associated with a conversion from negative values to positive ones. Reversed blood flow was documented in SMA at 2 h in 75% late preterm neonates. Preterm infants showed significantly higher mean peak systolic velocities (peak systolic velocity (PSV)SMA), end-diastolic velocities (EDVSMA) at 24 h and PSVTC at 72 h than term infants (p < .05). The resistance and pulsatility indices (PI) decreased within 24 h in both groups and inversely reflected the postnatal changes in EDVSMA. Mean PIAMS at 2 h was significantly higher in term neonates. CONCLUSION: Late preterm neonates show similar progressive postnatal increase in blood flow velocities accompanied with a decrease in vascular resistance in SMA and TC then term neonates.

Cholecystokinin-33, but not cholecystokinin-8 shows gastrointestinal site specificity in regulating feeding behaviors in male rats.

Two separate experiments were performed to localize the gastrointestinal sites of action regulating meal size (MS), intermeal interval (IMI) length and satiety ratio (SR, IMI/MS) by cholecystokinin (CCK) 8 and 33. Experiment 1: CCK-8 (0, 0.05, 0.15, 0.25nmol/kg) was infused in the celiac artery (CA, supplies stomach and upper duodenum) or the cranial mesenteric artery (CMA, supplies small and part of the large intestine) prior to the onset of the dark cycle in free feeding, male Sprague Dawley rats and MS (normal rat chow), IMI and SR were recorded. Experiment 2: CCK-33 (0, 0.05, 0.15, 0.25nmol/kg) were infused in the CA or the CMA, under the same experimental conditions above, and MS, IMI and SR were recorded. Experiment 1 found that CCK-8 reduces MS, prolongs the IMI and increases the SR at sites supplied by both arteries. Experiment 2 found that CCK-33 reduces MS and increases the SR at sites supplied by the CMA. We conclude that in male rats the feeding behaviors evoked by CCK-33, but not CCK-8, are regulated at specific gastrointestinal sites of action.

Solución del caso 12. Arteria renal derecha con origen aberrante / Solution to case 12. Aberrant origin in a right renal artery

No disponible

The BB2 receptor antagonist BW2258U89 attenuates the feeding responses evoked by exogenous gastrin releasing peptide-29.

This confirmatory work is aimed to test that the hypothesis that the gastrin releasing peptide (GRP) receptor - the BB2 receptor - is necessary for reduction of meal size (MS) and prolongation of the intermeal interval (IMI) by the small and the large forms of GRP in the rat, GRP-10 and GRP-29, and to confirm the sites of action regulating such responses - the vascular bed of the celiac artery (CA, supplying stomach and upper duodenum). To pursue these aims we measured first MS and IMI length in response to GRP-10 and GRP-29 (0, 0.5nmol/kg) infused in the CA (n=8 rats) and the cranial mesenteric artery (CMA, supplying the small and part of the large intestine, n=8 rats) in near spontaneously free feeding rats pretreated with the BB2 receptor antagonist BW2258U89 (0.1mg/kg) in the same arteries prior to the onset of the dark cycle. We found that GRP-29, but not GRP-10, infused by the CA reduced MS and prolonged the IMI by decreasing meal latency and meal duration and the BB2 receptor antagonist BW2258U89 infused in the same artery attenuated these responses. These results suggest that the BB2 receptor is necessary for reduction of MS and prolongation of the IMI by exogenous GRP-29, and the vascular bed of the CA, stomach and upper duodenum, contains sites of action regulating these feeding responses.

Acute effect of oral sensation of sweetness on celiac artery blood flow and gastric myoelectrical activity in humans.

Little is known about the effect of sweet taste stimulus on gastrointestinal motility and splanchnic blood flow. We examined whether gastric myoelectrical activity and/or celiac artery blood flow (CABF), which perfuses the stomach, are increased following an oral sensation of sweetness. After overnight fasting, 11 subjects rested for 5min and sipped, but not swallowed, one of four solutions for 1min. The fluid was then spat out, and subjects remained at rest for a further 10min. Fluids were approximately 15ml of three glucose solutions (4, 16, or 48%) or distilled water. Subjects completed trials with all four solutions in a randomized order. During each trial, gastric myoelectrical activity and CABF were continuously measured using electrogastrography and pulsed Doppler ultrasonography, respectively. None of the four solutions affected gastric myoelectrical activity. CABF was significantly increased after oral stimuli by all three glucose solutions, but not by water. There were no significant differences in the increments in CABF among the three glucose solutions. These results suggest that a sweet taste stimulus above a certain level of intensity acutely increases CABF during cephalic phase, without augmentation of gastric myoelectrical activity.

Sensibilidad al gluten no celíaca y enfermedades reumatológicas / Non-celiac gluten sensitivity and rheumatic diseases

La enfermedad celíaca es una enfermedad autoinmune sistémica que tiene entre sus manifestaciones clínicas síntomas frecuentes en las enfermedades reumatológicas, como dolor musculoesquelético crónico, astenia y fatiga mental. Se asocia a otras enfermedades autoinmunes, como la enfermedad de Sjögren. Es una enfermedad bien caracterizada con pruebas diagnósticas específicas. La sensibilidad al gluten no celíaca es una entidad emergente, con sintomatología similar a la de la enfermedad celíaca, pero sin pruebas diagnósticas específicas. Se revisan el concepto y los problemas diagnósticos de la sensibilidad al gluten no celíaca y se propone como hipótesis la asociación de la sensibilidad al gluten no celíaca a la fibromialgia, las espondiloartropatías y las enfermedades autoinmunes. Se describen observaciones clínicas que apoyan esta hipótesis, destacando el beneficio clínico del tratamiento de la sensibilidad al gluten (AU)

Celiac disease is an autoimmune systemic disease having among its clinical manifestations frequent symptoms common to rheumatologic diseases such as musculoskeletal pain, asthenia, and cognitive fatigue. It is associated with other autoimmune diseases like Sjögren disease. It is a well-characterized disease with specific diagnostic tests. Non-celiac gluten sensitivity is an emerging entity with symptoms similar to celiac disease, but without specific diagnostic tests. The concept of non-celiac gluten sensitivity and its diagnostic problems are reviewed, and the hypothesis of its association with fibromyalgia, spondyloarthritis, and autoimmune conditions is proposed. Clinical observations supporting the hypothesis are described, highlighting the benefit of treating non-celiac gluten sensitivity (AU)

Intra-Aortic Balloon Pump Malposition Reduces Visceral Artery Perfusion in an Acute Animal Model.

Visceral artery perfusion can be potentially affected by intra-aortic balloon pump (IABP) catheters. We utilized an animal model to quantify the acute impact of a low balloon position on mesenteric artery perfusion. In six pigs (78 ± 7 kg), a 30-cc IABP was placed in the descending aorta in a transfemoral procedure. The celiac artery (CA) and the cranial mesenteric artery (CMA) were surgically dissected. Transit time blood flow was measured for (i) baseline, (ii) 1:1 augmentation with the balloon proximal to the visceral arteries, and (iii) 1:1 augmentation with the balloon covering the visceral arteries. Blood flow in the CMA and CA was reduced by 17 and 24%, respectively, when the balloon compromised visceral arteries compared with a position above the visceral arteries (flow in mL/min: CMA: (i) 1281 ± 512, (ii) 1389 ± 287, (iii) 1064 ± 276, P < 0.05 for 3 vs. 1 and 3 vs. 2; CA: (i) 885 ± 370, (ii) 819 ± 297, (iii) 673 ± 315; P < 0.05 for 3 vs. 1). The covering of visceral arteries by an IABP balloon causes a significant reduction of visceral artery perfusion; thus, the positioning of this device during implantation is critical for obtaining a satisfactory outcome.

A Doppler velocimetry evaluation of intestinal blood flow characteristics in neonates receiving intravenous immunoglobulin therapy: a prospective observational study.

OBJECTIVES: To evaluate intestinal blood flow changes after intravenous immunoglobulin (IVIg) infusion among neonates with Rh isoimmunization and alloimmune thrombocytopenia. METHODS: This prospective observational study was conducted in level III NICU from July 2011 through August 2012. Thirty three consecutive instances (30 neonates) of IVIg treatment (1 g/kg) were studied. Celiac (CA) and superior mesenteric artery (SMA) doppler evaluations were performed immediately prior (baseline), immediately after and 12 to18 h following IVIg infusion. Peak systolic velocity, end diastolic velocity, time-averaged mean velocity, pulsatility index, resistive index and systolic/diastolic ratio were measured. The doppler indices measured immediately after and 12 to 18 h after IVIg infusion were compared with the baseline values. RESULTS: The mean gestation and birth weight of the cohort were 36 ± 2 wk and 2597 ± 563 g respectively. Doppler flow variables measured immediately after and 12 to 18 h after IVIg were comparable to baseline values, in both the arteries. However, systolic/diastolic ratio in SMA immediately post-IVIg was lower than baseline, [median (IQR): 5 (3, 9) vs. 7 (4, 14), respectively; p=0.02]. None of the study infants developed feed intolerance or necrotizing enterocolitis (NEC). CONCLUSIONS: There was no significant change in the celiac and SMA blood flows following IVIg therapy in neonates with Rh isoimmunization and alloimmune thrombocytopenia.

GLP-2 and mesenteric blood flow.

The 33 amino acid peptide hormone GLP-2 is produced by enteroendocrine L-cells, the density of which is highest in the ileum and the colon, in response to the presence of nutrients in the lumen. The biological effect of GLP-2 is mediated by activation of a G-protein-coupled 7-transmembrane receptor. GLP-2 receptors are expressed in the brainstem, lungs, stomach, small intestine and colon, but not in the heart. It has been shown in several animal studies that GLP-2 infusion increases intestinal blood flow and that this increase is confined to the small intestine. The aim of the three studies, on which the thesis is based, was to investigate basic physiological effects of GLP-2, in healthy volunteers and in SBS patients, with focus on the effects on mesenteric blood flow, blood flow at other vascular sites and effects on cardiac parameters. These parameters have been evaluated after both meal stimulation and GLP-2 administration. The studies showed the following results: Blood flow: In all three studies, blood flow changes in the SMA after GLP-2 administration were similar regarding changes over time and degree of change. Blood flow changes were similar to changes seen after a standard meal. Only RI changes were registered in all three studies, but the TAMV changes in study 2 and 3 had similar characteristics. Cardiovascular parameters: In all three studies no significant changes in blood pressure were registered in relation to GLP-2 administration. In study two and three, where cardiac parameters also were registered by impedance cardiography, increases in CO and SV were seen. Plasma GLP-2: There were, as expected, supraphysiological GLP-2 plasma levels after SC administration. All three studies have shown rapid changes in mesenteric blood flow after administration GLP-2. The changes have been the same both in regards to time to maximum changes (increase) and relatively close in regards to maximum extent of change. The changes in the SBS patients were less than in the healthy test subjects. The findings leave no doubt about that GLP-2 is a potent regulator of upper splanchnic blood flow. The study findings also support the notion that the observed increased mesenteric blood flow, isolated to the SMA, is secondary to the metabolic responses to GLP-2, and that these are likely due to a paracrine action by GLP-2 acting on GLP-2R bearing cells such as enteric neurons, probably expressing NO. In conclusion GLP-2 increases mesenteric blood flow in healthy subjects and in SBS patients, the increase is equivalent to a standard meal and dose dependent. The blood flow is not increased at other arterial vascular sites. GLP-2 does not acutely alter blood pressure, but increases, probably as compensation, pulse rate and cardiac output. GLP-2 induced vascular response in the superior mesenteric artery is related with the length of remaining intestine in SBS patients. The effect is therefore likely to reflect the metabolic activity in the tissue rather than direct effect on the vascular system.

γ-Aminobutyric acid-mediated neurotransmission in cerebellar-hypothalamic circuit attenuates gastric mucosal injury induced by ischemia-reperfusion.

BACKGROUND: Excessive greater splanchnic nerve (GSN) activation contributes to the progression of gastric ischemia-reperfusion (GI-R) injury. This study was designed to investigate the protective mechanism of cerebellar fastigial nucleus (FN) stimulation against GI-R injury. METHODS: The GI-R injury model was induced in rats by clamping the celiac artery for 30 min, and then reperfusion for 30 min, 1, 3, 6, or 24 h, respectively. KEY RESULTS: Microinjection of L-Glu (3, 6, 12 µg) into the FN dose-dependently attenuated GI-R injury and GSN activity. In addition, there was an enhancement of gastric mucosal blood flow in GI-R rats. Pretreatment with the glutamic acid decarboxylase antagonist into the FN, the GABAA receptor antagonist into the lateral hypothalamic area or lesion of superior cerebellar peduncle all reversed the protective effects of the FN stimulation. Furthermore, the FN stimulation reduced the TUNEL-positive gastric mucosal cell and Bax-positive gastric mucosal cell in GI-R rats. CONCLUSIONS & INFERENCES: These results indicate that the protective effects of the FN stimulation against GI-R injury may be mediated by attenuation of the excessive GSN activation, gastric mucosal cell apoptosis, and Bax expression in GI-R rats.

Physiological aspects of the determination of comprehensive arterial inflows in the lower abdomen assessed by Doppler ultrasound.

Non-invasive measurement of splanchnic hemodynamics has been utilized in the clinical setting for diagnosis of gastro-intestinal disease, and for determining reserve blood flow (BF) distribution. However, previous studies that measured BF in a "single vessel with small size volume", such as the superior mesenteric and coeliac arteries, were concerned solely with the target organ in the gastrointestinal area, and therefore evaluation of alterations in these single arterial BFs under various states was sometimes limited to "small blood volumes", even though there was a relatively large change in flow. BF in the lower abdomen (BF(Ab)) is potentially a useful indicator of the influence of comprehensive BF redistribution in cardiovascular and hepato-gastrointestinal disease, in the postprandial period, and in relation to physical exercise. BF(Ab) can be determined theoretically using Doppler ultrasound by subtracting BF in the bilateral proximal femoral arteries (FAs) from BF in the upper abdominal aorta (Ao) above the coeliac trunk. Prior to acceptance of this method of determining a true BF(Ab) value, it is necessary to obtain validated normal physiological data that represent the hemodynamic relationship between the three arteries. In determining BF(Ab), relative reliability was acceptably high (range in intra-class correlation coefficient: 0.85-0.97) for three arterial hemodynamic parameters (blood velocity, vessel diameter, and BF) in three repeated measurements obtained over three different days. Bland-Altman analysis of the three repeated measurements revealed that day-to-day physiological variation (potentially including measurement error) was within the acceptable minimum range (95% of confidence interval), calculated as the difference in hemodynamics between two measurements. Mean BF (ml/min) was 2951 ± 767 in Ao, 316 ± 97 in left FA, 313 ± 83 in right FA, and 2323 ± 703 in BF(Ab), which is in agreement with a previous study that measured the sum of BF in the major part of the coeliac, mesenteric, and renal arteries. This review presents the methodological concept that underlies BF(Ab), and aspects of its day-to-day relative reliability in terms of the hemodynamics of the three target arteries, relationship with body surface area, respiratory effects, and potential clinical usefulness and application, in relation to data previously reported in original dedicated research.

Classification of the celiac axis stenosis owing to median arcuate ligament compression, based on severity of the stenosis with subsequent proposals for management during pancreatoduodenectomy.

BACKGROUND: After pancreatoduodenectomy in patients with celiac axis stenosis or obstruction, it becomes problematic to maintain the upper abdominal organ blood flow, especially to the liver. The aim of this study was to investigate the celiac axis stenosis caused by median arcuate ligament (MAL) compression and to classify it according to preoperative image findings. METHODS: From January 1989 to November 2010, 562 patients underwent operations for diseases of the pancreatic head region in our department. To diagnose celiac artery compression by the MAL, angiography was used in the early period and 3-dimensional image reconstruction of multidetector-row computed tomography was used from 2004. The morphologic characteristics of the celiac axis stenosis were analyzed during intraoperative treatment. RESULTS: Twelve (2.1%) patients were diagnosed with MAL compression, and 8 of these patients only underwent MAL division to restore the celiac artery blood flow. One patient required conservation of the collateral circulation, and 2 patients needed arterial reconstruction. In the analysis of the level of origin of the celiac axis, there were no remarkable differences between nonstenotic and stenotic cases, or between mild and severe stenotic cases. Morphologic grades were defined based on the preoperative image findings and consequent intraoperative treatments. CONCLUSION: Preoperative grading of celiac axis stenosis could make pancreatoduodenectomy safer with maintenance of the upper abdominal organ blood flow in patients with MAL compression.

Effects of fenoldopam mesylate infusion on splanchnic perfusion after myocardial revascularization on cardiopulmonary bypass: an ultrasound Doppler study.

OBJECTIVES: To measure the effects of fenoldopam mesylate infusion on splanchnic blood flow in patients undergoing myocardial revascularization with cardiopulmonary bypass. DESIGN: An experimental observational study. SETTING: A single-institution community hospital. PARTICIPANTS: Eighteen patients undergoing on-pump coronary artery bypass graft surgery. INTERVENTIONS: Fenoldopam mesylate infusion (0.1 µg/kg/min). MEASUREMENTS AND MAIN RESULTS: Blood flow through the celiac artery, superior mesenteric artery, portal vein and hepatic artery were assessed by means of Doppler measurements. The main hemodynamic variables were measured using echocardiography. The infusion of fenoldopam significantly increased the blood flow through both celiac and superior mesenteric arteries by decreasing vascular resistance. The percentage of cardiac output directed to these 2 vessels increased significantly; the increase through the superior mesenteric artery was greater compared with the celiac artery. Portal vein and hepatic artery blood flow also consistently increased. No significant variations were observed with respect to hemodynamic variables. CONCLUSIONS: The infusion of fenoldopam increased the flow through the celiac artery and superior mesenteric artery; the effect was higher for the latter. These changes did not affect the hemodynamic variables.

Physiological changes in blood flow velocities in the superior mesenteric and coeliac artery in healthy term fetuses and newborns during perinatal period.

OBJECTIVE: The aim was to describe the course of physiological changes in coeliac artery (CA) and superior mesenteric artery (SMA) blood flow velocities (BFVs) during the perinatal period in healthy term fetuses and infants as it has not been studied in detail so far. METHODS: This prospective Doppler ultrasound study included 50 infants. The examinations were performed in a fetus after the completion of 36.0 gestation weeks before the onset of labor and in infants postnatally at the ages of 2, 24, and 72 h. RESULTS: The end-diastolic velocity (EDV) in the CA was generally higher than in the SMA (p < 0.001). The EDV in the SMA decreased postnatally (8.4 vs. -7.2, p < 0.001) and showed negative values in 92% of infants. By 24 h of postnatal age, EDV in the SMA had become positive in all of the infants (mean 13.8 cm/s, p < 0.001). The EDV in CA had only positive values. The changes in EDV in both vessels were reflected by changes in the resistance index in inverse manner. CONCLUSIONS: BFV in the CA and SMA changed dramatically in the perinatal period; the most remarkable changes occurred within the first 24 h of life.

Anatomical description of the trigeminal nerve [v] and its branching in mongrel dogs

For this study we had 10 (ten) dead bodies of dogs bearing different constitutional types. The following procedure for fixation was done in each animal: on both sides, the common carotid artery was cannulated and a 10% formaldehyde solution was then stilled. After fixation, the heads were separated from the bodies and the dissection of the target-region was performed according to classical dissection protocols, which included the removal of the skin and muscle and nerve exposition plus a further magnifying glass-aided dissection of the trigeminal nerve [V]. This study aimed to describe the anatomy of the main trunk and branching of the trigeminal nerve [V] on mongrel dogs, compare its characterization to those described in human beings and to obtain, data that conclude whether structural or branching differences of this nerve are closely related to different constitutional types of mongrel dogs.

Aneurisma de aorta torácica con cuello distal corto: técnica para aumentar la zona de sellado. A propósito de un caso / Aneurysm of the thorqacic aorta with a short distal neck: a technique to increase the sealing zone. A case report

Objetivo. Describir la experiencia personal inicial con una técnica para conseguir aumentar la zona de selladodistal de las endoprótesis en el tratamiento endovascular de aneurismas de aorta torácica (AAT) con cuello distal corto,aprovechando los 4 mm distales festoneados de la endoprótesis Gore TAG. Caso clínico. Mujer de 63 años, con antecedentesde hipertensión arterial, diabetes mellitus, cardiopatía isquémica y dislipidemia. Intervenida de apendicectomíae histerectomía. Con seguimiento en consulta externa de cirugía vascular por AAT, con crecimiento rápido de 15 mmen un año, motivo por el que se decide el tratamiento. En angio-TC toracoabdominal: AAT 50 mm de diámetro máximo.Cuello proximal de 35 mm de longitud y distal hasta el tronco celíaco de 10 mm. Técnica quirúrgica: con anestesia generaly protección medular (drenaje de líquido cefalorraquídeo), se procedió a la cateterización del tronco celíaco con balónde 2,5 mm vía transfemoral derecha e implantación de dos endoprótesis tipo Gore TAG de 28 × 15 y 31 × 15, respectivamente,por vía ilíaca izquierda a través de una prótesis de dacrón de 8 mm suturada terminolateral a ésta. En el seguimientocon angio-TC, al año se comprueba la correcta exclusión del aneurisma, sin evidencia de fugas periprotésicas,con permeabilidad del tronco celíaco. Conclusiones. La técnica de tutorización de los troncos viscerales mediante infladointraluminal de balón de angioplastia no sólo asegura su preservación durante el despliegue de la endoprótesis torácica,sino que además permite, de una forma segura, aumentar la zona de sellado distal en AAT con cuellos distales cortos(AU)

Aim. To describe our initial personal experience with a technique for increasing the distal sealing zone ofstent-grafts in the endovascular treatment of thoracic aortic aneurysms (TAA) with a short distal neck, by takingadvantage of the 4 mm scalloped flare at the distal end of the Gore TAG endoprosthesis. Case report. A 63-year-oldfemale with a history of arterial hypertension, diabetes mellitus, ischaemic heart disease and dyslipidaemia. The patienthad undergone an appendectomy and a hysterectomy. She was also attending the vascular surgery outpatientdepartment to follow up a TAA with a rapid growth rate of 15 mm per year, which is what led to the decision being takento treat it immediately. In a thoracoabdominal CT-angiography scan: TAA with a maximum diameter of 50 mm.Proximal neck with a length of 35 mm and distally, to the celiac trunk, 10 mm. Surgical technique: with generalanaesthesia and spinal cord protection (cerebrospinal fluid drainage), the celiac trunk was catheterised with a 2.5-mmballoon via right transfemoral, and placement of two 28 × 15 and 31 × 15 Gore TAG type endoprostheses, respectively,via the left iliac through an 8-mm Dacron graft that was sutured end-to-side to it. In the next CT-angiography scan atone year, the aneurysm was seen to be correctly excluded, with no evidence of periprosthetic leaks, and patency in theceliac trunk. Conclusions. The technique of tutoring the main visceral arteries by inflating an intraluminal angioplastyballoon not only ensures their preservation during deployment of the thoracic endoprosthesis, but also makes it possibleto safely increase the distal sealing zone in TAA with short distal necks(AU)

Fetal celiac and splenic artery flow velocity and pulsatility index: longitudinal reference ranges and evidence for vasodilation at a low portocaval pressure gradient.

OBJECTIVES: To establish longitudinal reference ranges for the fetal celiac and splenic arteries flow velocity and pulsatility index (PI), and to determine their hemodynamic relationship to venous liver perfusion and distribution and to other essential arteries. METHODS: This was a prospective longitudinal study of 161 low-risk pregnancies. Doppler recordings of the celiac and splenic arteries were made on three to five occasions at 3-5-week intervals to establish reference ranges for blood velocity and PI measurements. Peak systolic velocity in the ductus venosus, a shunt between the umbilical and inferior caval veins, was used to represent the umbilicocaval (i.e. portocaval) pressure gradient, and the left portal vein blood velocity represented the umbilical distribution to the right liver lobe. The correlations between the celiac, splenic and hepatic arteries were determined, and their association with the middle cerebral and umbilical artery PIs (MCA-PI and UA-PI) was assessed. RESULTS: Longitudinal reference ranges for the fetal celiac and splenic arteries were established based on 510 and 521 observations, respectively, during gestational weeks 21-39. Terms for calculating conditional reference ranges to be used for repeat observations are provided. Celiac and splenic artery PIs were low when portocaval pressure and umbilical supply to the right lobe were low (P < 0.0001). Their peak systolic velocity and PI were correlated (r = 0.7 (95% CI, 0.6-0.8) and r = 0.5 (95% CI, 0.3-0.6), respectively), while the PI of the hepatic artery correlated weakly with those of the celiac and splenic arteries. They were positively associated with the MCA-PI and UA-PI (P < 0.0001). CONCLUSION: We provide longitudinal reference ranges for the fetal celiac and splenic arteries Doppler measurements and show that they are involved in maintaining portal liver perfusion independently from the hepatic artery.

Otolithic activation on visceral circulation in humans: effect of aging.

Engagement of the otolith organs elicits differential activation of sympathetic nerve activity and vascular responses to muscle and skin in humans. Additionally, aging attenuates the otolith organ-mediated increases in muscle sympathetic nerve activity in older adults. In this study, we hypothesized that 1) the vestibulosympathetic reflex (VSR) would elicit visceral vascular vasoconstriction and 2) visceral vascular response to the VSR would be attenuated in older subjects compared with young. To test these hypotheses, heart rate, mean arterial blood pressure, and renal, celiac trunk, and superior mesenteric arterial blood velocity (Doppler ultrasound) were measured in 22 young (25+/-1 yr) and 18 older (65+/-2 yr) healthy subjects during head-down rotation (HDR), which selectively activates the otolith organs. Mean arterial pressure and heart rate did not change from baseline during HDR in young or older subjects. Renal blood velocity (Delta -2+/-1 cm/s) and vascular conductance (Delta -0.03+/-0.01 cm.s(-1).mmHg(-1)) significantly decreased from baseline during HDR (P<0.05) in young subjects. In contrast, renal blood velocity and conductance did not change in older subjects (Delta -0.2+/-1 cm/s and Delta0.02+/-0.08 mmHg.cm(-1).s(-1), respectively) during HDR. Superior mesenteric and celiac blood velocity and vascular conductance did not change in response to HDR in either the young or older subjects. These data suggest that renal vasoconstriction occurs during otolith organ activation in young but not older humans. Together with our previous studies, we conclude that the VSR elicits a diverse patterning of sympathetic outflow that results in heterogeneous vascular responses in humans and that these responses are significantly attenuated in older humans.