Effi cacy of partial and complete resuscitative endovascular balloon occlusion of the aorta in the hemorrhagic shock model of liver injury

BACKGROUND:Resuscitative endovascular balloon occlusion of the aorta(REBOA)can temporarily control traumatic bleeding.However,its prolonged use potentially leads to ischemia-reperfusion injury(IRI).Partial REBOA(pREBOA)can alleviate ischemic burden;however,its security and eff ectiveness prior to operative hemorrhage control remains unknown.Hence,we aimed to estimate the effi cacy of pREBOA in a swine model of liver injury using an experimental sliding-chamber ballistic gun.METHODS:Twenty Landrace pigs were randomized into control(no aortic occlusion)(n=5),intervention with complete REBOA(cREBOA)(n=5),continuous pREBOA(C-pREBOA)(n=5),and sequential pREBOA(S-pREBOA)(n=5)groups.In the cREBOA and C-pREBOA groups,the balloon was inflated for 60 min.The hemodynamic and laboratory values were compared at various observation time points.Tissue samples immediately after animal euthanasia from the myocardium,liver,kidneys,and duodenum were collected for histological assessment using hematoxylin and eosin staining.RESULTS:Compared with the control group,the survival rate of the REBOA groups was prominently improved(all P<0.05).The total volume of blood loss was markedly lower in the cREBOA group(493.14±127.31 mL)compared with other groups(P<0.01).The pH was significantly lower at 180 min in the cREBOA and S-pREBOA groups(P<0.05).At 120 min,the S-pREBOA group showed higher alanine aminotransferase(P<0.05)but lower blood urea nitrogen compared with the cREBOA group(P<0.05).CONCLUSION:In this trauma model with liver injury,a 60-minute pREBOA resulted in improved survival rate and was effective in maintaining reliable aortic pressure,despite persistent hemorrhage.Extended tolerance time for aortic occlusion in Zone I for non-compressible torso hemorrhage was feasible with both continuous partial and sequential partial measures,and the significant improvement in the severity of acidosis and distal organ injury was observed in the sequential pREBOA.

Totally Occluded Coarctation of the Aorta in a Young Adult

We report the case of a 20-year-old female patient presenting with a totally occluded coarctation of the aorta. The patient was admitted for the evaluation of resistant grade III high blood pressure. The physical examination revealed a blood pressure gradient between the upper and lower limbs, absent femoral pulses, a diffuse continuous murmur over the chest, and hyperpulsatility of the carotid arteries and sternal notch. A transthoracic echocardiography outlined a narrowing in the caliber of the isthmic aorta without acceleration of flow or gradient. Thoracic CT angiography revealed a complete aortic coarctation with interruption of continuity between segment 3 and the descending aorta.

Influence of Angiotensin II on α1-Adrenergic Receptors Function in Rat Aorta and Expression in Vascular Smooth Muscle Cells

Angiotensin II (Ang II) is the main mediator of the Renin-Angiotensin-System acting on AT1 and other AT receptors. It is regarded as a pleiotropic agent that induces many actions, including functioning as a growth factor, and as a contractile hormone, among others. The aim of this work was to examine the impact of Ang II on the expression and function of α1-adrenergic receptors (α1-ARs) in cultured rat aorta, and aorta-derived smooth muscle cells. Isolated Wistar rat aorta was incubated for 24 h in DMEM at 37˚C, then subjected to isometric tension and to the action of added norepinephrine, in concentration-response curves. Ang II was added (1 × 10−5 M), and in some experiments, 5-Methylurapidil (α1A-AR antagonist), AH11110A (α1B-AR antagonist), or BMY-7378 (α1D-AR antagonist), were used to identify the α1-AR involved in the response. Desensitization of the contractile response to norepinephrine was observed due to incubation time, and by the Ang II action. α1D-AR was protected from desensitization by BMY-7378;while RS-100329 and prazosin partially mitigated desensitization. In another set of experiments, isolated aorta-derived smooth muscle cells were exposed to Ang II and α1-ARs proteins were evaluated. α1D-AR increased at 30 and 60 min post Ang II exposure, the α1A-AR diminished from 1 to 4 h, while α1B-AR remained unchanged over 24 h of Ang II exposure. Ang II induced an increase of α1D-AR at short times, and BMY-7378 protected α1D-AR from desensitization.

Endogenous Norepinephrine Desensitizes α1D-Adrenoceptors in Cultured Rat Aorta

Desensitization is a process characterized by the loss of cellular response to an agonist when this is present for a long time. α1D-adrenergic receptor (α1D-AR) desensitization is important since this receptor is involved in the contraction of large caliber arteries, such as the aorta. The aim of this research was to evaluate the desensitization of α1D-AR due to the endogenous release of norepinephrine in cultured rat aorta. Wistar rat aorta was incubated for 2 h or 24 h in DMEM at 37°C, and then subjected to isometric tension and the action of added norepinephrine, in concentration-response curve (CRC). In some experiments, BMY-7378 (α1D-AR antagonist) or 5-methylurapidil (α1A-AR antagonist) was used to identify the α1-AR involved in the response, or BMY-7378 to protect the α1D-AR from desensitization. Results showed that α1D-AR was desensitized when the aorta was incubated for 24 h, since the CRC to exogenous norepinephrine showed lower maximal contraction and the curve was displaced to the right, indicating that the receptor involved in contraction was not the α1D-AR, as compared to the aorta incubated 2 h. The receptor stimulated by norepinephrine at 24 h was neither the α1A-AR, as shown by the lack of displacement of the curve by 5-methylurapidil, but rather it seems that α1B-AR is inducing contraction. When the aorta was incubated with BMY-7378 for 24 h, the α1D-AR antagonist protected the receptor from desensitization. Endogenous norepinephrine desensitizes α1D-AR in the cultured aorta, and the α1D-AR is protected by BMY-7378.

Case Report of a Pseudoaneurysm of Ascending Aorta Treated by Stent

Pseudoaneurysms of the ascending aorta are a rare complication of aortic and cardiac surgery. In this article, we present a clinical case of a 56-year-old patient with a fortuitous diagnosis of a pseudoaneurysm of ascending aorta that was treated by an endovascular stent-graft. We discuss in this article the diagnostic and therapeutic aspect of the case and the place of endovascular treatment for the ascending aorta.

Surgical strategies for severely atherosclerotic(porcelain)aorta during coronary artery bypass grafting

Porcelain aorta(PA)is an asymptomatic atherosclerotic disease,characterized by circumferential calcification throughout the whole perimeter of the aorta.It is seen in 2%to 9.3%of patients undergoing elective coronary artery bypass grafting(CABG)and makes manipulation of the ascending aorta impossible.It has been clearly shown that most emboli seen and detected during the CABG procedure occur during aortic cross-clamping and aortic side-clamping.Manipulation of porcelain or a severely atherosclerotic aorta increases the risk of perioperative stroke.The incidence of stroke after CABG is between 0.48%and 2.9%,and the risk is correlated with the extent and severity of the atherosclerotic disease.A conventional CABG procedure involves successive steps that include cannulation of the ascending aorta,application of a cross-clamp to the aorta,and partial clamping of the aorta to create the proximal anastomosis.Therefore in procedures that involve cannulation,clamping,or proximal anastomosis,and where aortic manipulation is inevitable,preassessment of the atherosclerotic aortic plaques is crucial.Although many surgeons still rely on intraoperative manual aortic palpation,this approach has very low sensitivity and underestimates the severity of the atherosclerotic illness.Imaging methods including preoperative computed tomography or intraoperative epiaortic ultrasonography enable modification of the surgical technique according to the severity of atherosclerosis.Various surgical techniques have been described to reduce the risk of atheroembolism that may lead to cerebrovascular events in patients with severely atherosclerotic ascending aorta.Anaortic or“no-touch”techniques that do not utilize aortic manipulation may significantly decrease the development of neurological complications by avoiding aortic maneuvers known to cause emboli.In cases where severe atherosclerotic disease or other factors preclude safe use of the ascending aorta,modifications in the surgical techniques,such as switching to different cannulation sites including the axillary/subclavian,femoral and innominate arteries,or using hypothermic ventricular fibrillation and in-situ pedicled arterial grafts,or performing proximal anastomoses at alternative anatomical locations will enable CABG operations to be performed safely with low morbidity and mortality rates in patients with porcelain aortas.

Coarctation of the aorta:Management from infancy to adulthood

Coarctation of the aorta is a relatively common form of congenital heart disease, with an estimated incidence of approximately 3 cases per 10000 births. Coarctation is a heterogeneous lesion which may present across all age ranges, with varying clinical symptoms, in isolation, or in association with other cardiac defects. The first surgical repair of aortic coarctation was described in 1944, and since that time, several other surgical techniques have been developed and modified. Additionally, transcatheter balloon angioplasty and endovascular stent placement offer less invasive approaches for the treatment of coarctation of the aorta for some patients. While overall morbidity and mortality rates are low for patients undergoing intervention for coarctation, both surgical and transcatheter interventions are not free from adverse outcomes. Therefore, patients must be followed closely over their lifetime for complications such as recoarctation, aortic aneurysm, persistent hypertension, and changes in any associated cardiac defects. Considerable effort has been expended investigating the utility and outcomes of various treatment approaches for aortic coarctation, which are heavily influenced by a patient's anatomy, size, age, and clinical course. Here we review indications for intervention, describe and compare surgical and transcatheter techniques for management of coarctation, and explore the associated outcomes in both children and adults.

The life-saving emergency thoracic endovascular aorta repair management on suspected aortoesophageal foreign body injury

BACKGROUND:Fatal aortic rupture caused by esophageal foreign body(EFB),is associated with a high mortality,but can be prevented by thoracic endovascular aorta repair(TEVAR)that performed increasingly as technology improves.This study aims to investigate the cause,management and prognosis of suspected penetrating aortoesophageal foreign body injury.METHODS:Twelve cases who met the criteria were enrolled in this study.The demographic and clinical data were reviewed for evaluating the characteristics of EFB.RESULTS:Among 12 cases enrolled,7 were males and 5 were females,with an age 27–86 years.The distance of EFB from aorta(DFA)of 7 cases were less than or equal to 0 mm,5 cases were 0–2 mm.Eleven cases were managed with TEVAR,only one case was with open surgery standby but finally treated by flexible endoscopy(FE)successfully,without TEVAR.In group with TEVAR,EFB of 7 cases were successfully removed by rigid endoscopy(RE),and one of them was failed at the first RE treatment.EFB of 2 cases were successfully removed by open surgery with TEVAR,and other 9 cases were managed by endoscopies with TEVAR.The mean length of stay of hospitalization(LOS)and length of ICU stay of patients treated by open surgery with TEVAR(18.50±2.12 days and 5.50±0.71 days)was significantly longer than those of patients treated by endoscopy with TEVAR(7.00±2.74 days and 1.33±1.12 days,P<0.001 and P=0.001,respectively).Five cases had severe complications.CONCLUSION:Rational application of TEVAR can be a life-saving management for aortoesophageal foreign body injury,and jointed with endoscopy is safe and effective with a shorter length of ICU or total hospital stay.

The Inhibitory Effect of Astilbin on the Arteriosclerosis of Murine Thoracic Aorta Transplant

The inhibitory effect of astilbin on transplant arteriosclerosis in murine model of thoracic aorta transplantation was examined. Model of rat thoracic aorta transplantation was established. Ninety rats were divided into three groups. In isograft group, the thoracic aorta of Brown Norway （BN） rat was anastomosed with the abdominal aorta of another BN rat. In allograft group, the thoracic aorta of BN rat was anastomosed with the abdominal aorta of Lewis rat. In astilbin group, the rats receiving allo-transplantation were given astilbin 5 mg/kg per day for a time of 28 days. The donor thoracic aorta and the recipient abdominal aorta were anastomosed by means of a polyethylene can- nula （inner diameter： 1.5 mm, length： 3 mm length）. The grafts were histologically examined for structural changes. The areas of arterial lumen and endatrium were calculated. Our results showed that, in the allograft group, 28 days after allografting, conspicuous proliferation of smooth muscles and infiltration with a great number of inflammatory cells were found in the tunica intima and tunica media. Astilbin significantly inhibited the proliferation of smooth muscles and ameliorated the infiltration of inflammatory cells thereyby prevent against the development of transplant arteriosclerosis. It is concluded that asltilbin can effectively prevent the development of arteriosclerosis in allotransplant by inhibiting the proliferation of smooth muscles and inhibit the proliferation of smooth muscles in tunica of intima and media and reducing infiltration of the inflammatory cells.

Management of adults with coarctation of aorta

Coarctation of the aorta(CoA)is a relatively common congenital cardiac defect often causing few symptoms and therefore can be challenging to diagnose.The hallmark finding on physical examination is upper extremity hypertension,and for this reason,CoA should be considered in any young hypertensive patient,justifying measurement of lower extremity blood pressure at least once in these individuals.The presence of a significant pressure gradient between the arms and legs is highly suggestive of the diagnosis.Early diagnosis and treatment are important as long-term data consistently demonstrate that patients with CoA have a reduced life expectancy and increased risk of cardiovascular complications.Surgical repair has traditionally been the mainstay of therapy for correction,although advances in endovascular technology with covered stents or stent grafts permit nonsurgical approaches for the management of older children and adults with native CoA and complications.Persistent hypertension and vascular dysfunction can lead to an increased risk of coronary disease,which,remains the greatest cause of long-term mortality.Thus,blood pressure control and periodic reassessment with transthoracic echocardiography and threedimensional imaging(computed tomography or cardiac magnetic resonance)for should be performed regularly as cardiovascular complications may occur decades after the intervention.

Endoscopic trans-esophageal submucosal tunneling surgery:A new therapeutic approach for diseases located around the aorta ventralis

AIM To assess the efficiency of endoscopic trans-esophageal submucosal tunneling surgery(EESTS) technique for diseases located around the aorta ventralis.METHODS Nine pigs were assigned to EESTs. The procedures were as follows: First, a long esophageal submucosal tunnel was established. Second, full-thickness myotomy was created. Third, an endoscope was entered into the abdominal cavity through a muscle incision and the endoscope was around the aorta ventralis. Eventually,celiac trunk ganglion neurolysis, partial hepatectomy and splenectomy, partial tissue resection in the area of the posterior peritoneum, and endoscopic submucosal dissection(ESD) combined with lymph node dissection were performed. The animals were given antibiotics for 5 d and necropsied 7 d after surgery.RESULTS In all surgeries, one pig died from intraperitoneal hemorrhage after doing partial splenectomy, while the other pigs were alive after successfully operating other surgeries. For surgery of celiac trunk ganglion damage, at necropsy, there was no exudation in the abdominal cavity. Regarding surgery of partial hepatectomy, the wound with part healing was observed in the left hepatic lobe, and no bleeding or obvious exudation was seen. In surgery of partial splenectomy, massive hemorrhage was observed on the splenic wound surface, and the metal clips could not stop bleeding. After surgery of retroperitoneal tissue resection, mild tissue adhesion was observed in the abdominal cavity of one animal, and another one suffered from severe infection. For surgery of ESD and lymph node dissection, a moderate tissue adhesion was observed.CONCLUSION EESTS is a feasible and safe technique for diseases located around the aorta ventralis.

Left to Right Extracardial Shunt to Control Hemorrhage of Ascending Aorta and Left Ventricle: A Report of 3 Cases

Presented in this paper are 3 cases of hemorrhage of ascending aorta and left ventricle after open heart surgery treated by extracardial bypass in our hospital from Oct. 1994 to Dec. 1995. Remained aneurysmal wall enclosing conduit graft was used as a sac bypassed to right atrium to form a extracardial left-toright shunt in order to control bleeding and the results turned out to be satisfactory. The bypass and hemodynamically ignorable shunt can close spontaneously without complications with recovery of coagulation system. The technique may find wide application in clinical practice.

Morphology of the ascending aorta: a study on 114 Chinese patients

Purpose: This study aimed to investigate the morphological characteristics of ascending aortic dissection in detail. Materials and Methods: The ascending aorta was morphologically assessed in a consecutive series of patients between January 2009 and October 2014. A new assessment and evaluation method was used to describe 114 patients with ascending aortic dissection. Results: A large difference was found in the degree of curvature between the ascending aorta with and without dissection. The shape of the former was straighter and steeper(control group R, 47.46 ± 6.40 mm; experimental group R, 59.70 ± 10.27 mm, P < 0.001). In the case of aortic dissection involving the valves, the proximal edge of the first entry was obviously close to the aortic sinus. The orientation of the entries was mainly around the 10 o'clock and 1–2 o'clock positions, and most of their shapes were fusiform(111; 70.02%). The distance of the distal extending dissection was associated with cases involving the branch arteries(involving three branches 441.40 ± 101.13 mm vs 159.85 ± 131.86 mm in others, P < 0.001). Conclusion: The morphological features of the ascending aorta after dissection and the correlations among dissections, entries, and related factors were found.

Clinical Study of the Ascending Aorta Wall Motion by Velocity Vector Imaging in Patients with Primary Hypertension

We studied the wall motion characteristics of the ascending aorta by velocity vector imaging （VVI） in primary hypertension patients. The ascending aortas both in 30 patients with primary hypertension and 30 normal controls were examined by Acuson sequoia 512 equiped with VVI. The maximum velocity （Vs, Ve） of every point on the anterior wall of ascending aorta both in systole and diastole was measured. The aortic diameter was wider in the hypertension patients than that in the healthy subjects （P〈0.05）. The movement amplitude of the anterior wall of the ascending aorta in long axis view in the hypertension patients was lower than that in the healthy subjects （P〈0.05）. The motion and time to peak in systole of each point of the ascending aorta in the healthy subjects had no significant difference （P〉0.05）. The velocity curves of the anterior wall of ascending aorta both in the hypertension and healthy subjects were regular, and the curve in systole was named S wave and that in diastole named E wave. The velocity of S wave and E wave was slower in the hypertension patients than that in the healthy subjects （P〈0.05）. The time to peak of S wave on the anterior wall of ascending aorta in systole was shorter in the hypertension patients than in the healthy subjects （P〈0.05）. VVI could be used to accurately and directly observe the movement character of the ascending aorta walls, which would help us understand the elasticity of great arteries in patients with hypertension.

Noninvasive Assessment of Cardiac Index with Transesophageal Echocardiography in Patients Undergoing Mitral Valve Replacement: A Comparison between Determinations at the Mitral Valve and the Ascending Aorta

Methods: Sixteen patients with American Society of Anesthesiologists status (ASA) II-III, age ≤ 70 yr, male or female, preoperatively NYHA II-III and EF ≥ 45%, scheduled for mitral valve replacement (MVR) were studied. Complete intravenous general anesthesia was used for induction and anesthesia maintenance. After anesthesia induction we put the TEE probe into the esophagus. The cardiac index was determined at three periods following MVR: T1 30 minutes later following cessation of bypass, T2 60 minutes after cessation of bypass, T3 90 minutes after cessation of bypass. Statistical analysis was made with the Bland and Altman method. Results: Ninety-six measurements were compared. The cardiac index values at the level of prosthesis mitral valve (CIMV) ranged from 1.3 to 5.5 L·min-1·m-2 (mean 2.6 ± 0.9). The Values of cardiac index at aortic valve (CIAA) ranged from 2.7 to8.8 L·min-1·m-2 (mean 4.9 ± 1.7). Bias was -2.3 L·min-1·m-2 and limits of agreement -5.6 to 1.0 L·min-1·m-2. Conclusion: During mitral valve replacement, doubtful correlations were observed between values of cardiac index at the mitral valve and the ascending aorta using TEE.

Doppler measurements in fetal descending aorta and umbilical artery can predict borderline oxygenation in pre-eclampsia and HELLP syndrome

Objective: To determine diagnostic utility of Doppler measurements in fetal descending aorta and umbilical arteries in predicting intrauterine growth retarded (IUGR) fetuses at risk in pregnancies complicated by preeclampsia and/or HELLP syndrome. Methods: Doppler measurements were taken in fetal descending aorta and umbilical arteries of 53 patients with pre-eclampsia, 10 of whom had HELLP syndrome using fetometry (ACUSON 128XP/10, 3.5 MHz probe). These values were compared with those of 44 appropriate-for-gestational age singleton pregnancies (AGA). Doppler Indices (Resistance Index (RI), Systolic/Diastolic (S/D) ratio) and end-diastolic flows were related to fetal heart rate (FHR) during contraction stress test, to cord blood parameters (pH, Base Excess) and to Apgar Scores. Results: In contrast to AGA fetuses, IUGR fetuses had decreased end-diastolic flow and an increase of Doppler Indices significantly earlier in the descending aorta (p < 0.05), compared to umbilical artery. Increased RI’s, S/D ratios and a decrease of end-diastolic flow in fetal aorta were significantly correlated to frequency of FHR decelerations during contraction stress tests, pH, Base Excess (p < 0.01) and Apgar Scores in IUGR fetuses. Conclusion: A decrease in end-diastolic flow paralleled with an increase in Doppler indices in fetal descending aorta reflect oxygen deprivation in IUGR fetuses during pre-eclamptic pregnancies with or without HELLP syndrome. While ductus venosus and umbilical artery are more frequently used nowadays to determine fetal oxygen deprivation, Doppler measurements in fetal descending aorta provide additional information for early detection of fetuses at risk for IUGR in pregnancies complicated with pre-eclampsia and/or HELLP

Correlation between thoracic aorta 18F-natrium fluoride uptake and cardiovascular risk

AIM: To investigating the relationship between thoracic and cardiac 18F-Natrium-Fluoride (18F-NaF) uptake, as a marker of ongoing calcification and cardiovascular risk factors.METHODS: Seventy-eight patients (44 females, mean age 63, range 44-83) underwent whole body 18F-NaF positron emission tomography/computed tomography. Cardiovascular risk (CVR) was used to divide these patients in three categories: Low (LR), medium (MR) and high risk (HR). 18F-NaF uptake was measured by manually drawing volumes of interest on the ascending aorta, on the aortic arch, on the descending aorta and on the myocardium; average standardized uptake value was normalized for blood-pool, to obtain target-to-background ratio (TBR). Values from the three aortic segments were then averaged to obtain an index of the whole thoracic aorta.RESULTS: A significant difference in whole thoracic aorta TBR was detected between HR and LR (1.84 ± 0.76 vs 1.07 ± 0.3, P < 0.001), but also between MR and HR-LR (1.4 ± 0.4, P < 0.02 and P < 0.01, respectively). Significance of this TBR stratification strongly varied among thoracic aorta subsegments and the lowest P values were reached in the descending aorta (P < 0.01). Myocardial uptake provided an effective CVR classes stratification (P < 0.001).Correlation between TBR and CVR was appreciable when the whole thoracic aorta was considered (R = 0.67), but it peaked when correlating the descending thoracic segment (R = 0.75), in comparison with the aortic arch and the ascending segment (R = 0.55 and 0.53, respectively).CONCLUSION: Fluoride uptake within the thoracic aorta wall effectively depicts patients’ risk class and correlates with cardiovascular risk. Descending aorta is the most effective in CVR determination.

Sleeve gastrectomy prevents lipoprotein receptor-1 expression in aortas of obese rats

AIM: To investigate the effects of sleeve gastrectomy on adipose tissue infiltration and lectin-like oxidized low density lipoprotein receptor-1 (LOX-1) expression in rat aortas. METHODS: Twenty-four rats were randomized into three groups: normal chow (control), high fat diet (HD) and high fat diet with sleeve gastrectomy (SG). After surgery, the HD and SG groups were fed a high fat diet. Animals were sacrificed and plasma high density lipoprotein (HDL) and low density lipoprotein (LDL) levels were determined. LOX-1 protein and LOX-1 mRNA expression was also measured. Aortas were stained with Nile red to visualize adipose tissue. RESULT: Body weights were higher in the HD group compared to the other groups. HDL levels in control,HD, and SG groups were 32.9 ± 6.2 mg/dL, 43.4 ± 4.0 mg/dL and 37.5 ± 4.3 mg/dL, respectively. LDL levels in control, HD, and SG groups were 31.8 ± 4.5 mg/dL, 53.3 ± 5.1 mg/dL and 40.5 ± 3.7 mg/dL, respectively. LOX-1 protein and LOX-1 mRNA expression was greater in the HD group versus the other groups. Staining for adipose tissue in aortas was greater in the HD group in comparison to the other groups. Thus, a high fat diet elevates LOX-1 protein and mRNA expression in aorta. CONCLUSION: Sleeve gastrectomy decreases plasma LDL levels, and downregulates LOX-1 protein and mRNA expression.

Correlation of the CT values of abdominal aorta,renal artery and renal cortex with its thickness on 64-MDCT contrast enhanced imagesCorrelation of the CT values of abdominal aorta,renal artery and renal cortex with its thickness on 64-MDCT contrast enhance

Objective:To investigate the correlation of abdominal aorta CT value,renal artery CT value and renal cortex thickness with renal cortex CT value on contrast enhanced 64-slice CT images.Methods:96patients(50 men and 46women;16~74years)with normal kidney function,which was confirmed by kidney function test were enrolled in this study,including bilateral kidneys of 92cases and unilateral kidney of 4cases(total of 188kidneys;92left,96right).After intravenous(IV)injection of contrast agent the kidneys of the selected patients were scanned by MDCT.The scans were performed in arterial,venous and 3min delayed phases.All statistical analyses were performed by using IBM SPSS 20.0.Graphs were generated using Graph Pad Prism 5software.Quantitative data were presented as mean±standard deviation,while qualitative data were presented as frequency(%).P<0.05was considered to be statistically significant.Results:The mean renal cortex thickness was(5.19±0.81)mm in all kidneys.In the arterial phase,a statistically significant positive correlation between renal cortex CT values and abdominal aortic CT values was showed(r=0.584;P<0.001).A statistically significant positive correlation between renal cortex CT values and renal cortex thickness was demonstrated(r=0.533,P<0.0001).Likewise,there was a positive correlation between renal cortex CT value and renal artery CT values(r=0.43,P<0.001).Conclusion:It is a promising approach to assess the individual kidney function by measuring abdominal aorta CT value,renal artery CT value,renal cortex CT value and renal cortex thickness using contrast MDCT.

Effect of Patient-Specific Aorta Wall Properties on Hemodynamic Parameters

This study deals with the interaction of blood flow with the wall aorta,i.e.,the boundary of the main artery that transports blood in the human body.The problem is addressed in the framework of computational fluid dynamics complemented with(FSI),i.e.,a fluid-structure interaction model.Two fundamental types of wall are considered,namely a flexible and a rigid boundary.The resulting hemodynamic flows are carefully compared in order to determine which boundary condition is more effective in reproducing reality.Special attention is paid to wall shear stress(WSS),a factor known for its ability to produce atherosclerosis and bulges.Laminar flow conditions are assumed.The result show that the flexible wall can produce higher WSS and pressure drop compared to the rigid aorta case.