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Arterial Blood Flow (arterial + blood_flow)
Selected AbstractsClinical course linkage among different priapism subtypes: Dilemma in the management strategiesINTERNATIONAL JOURNAL OF UROLOGY, Issue 11 2008Shin-ichi Hisasue Objectives: Priapism is a rare condition whose management differs according to the etiology. We report the clinical course of three forms of priapism to assess the feasibility and safety of recent management strategies. Methods: The study included eight patients complaining of persistent erection for ,4 h who were treated in our institution between January 1996 and July 2007. Results: Overall, we categorized 12 cases of priapism in eight patients divided as follows: five cases of ischemic priapism (IP), three of stuttering priapism (SP), and four of non-ischemic priapism (NIP). Two of five IP patients needed a shunt procedure, which led to the subsequent erectile dysfunction. The other three were treated successfully with a corporal injection of sympathomimetic agents and subsequently suffered from SP. One of the three SP patients suffered from mimicked NIP with increased arterial blood flow during the initial treatment for IP. Four of the NIP patients including the mimicked one achieved complete detumescence, through arterial embolization in two and conservative management in two. Conclusions: Current management seems effective and safe in the short-term. However, the long-term outcome of the treatment for IP is still disappointing. Careful long-term observation is needed for an appropriate management. [source] Paradoxical Vasodilation During Lower Body Negative Pressure in Patients with Vasodepressor Carotid Sinus SyndromeJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 6 2003Arduino A. Mangoni MD OBJECTIVES: To elucidate the pathophysiological mechanism of the vasodepressor form (VD) of carotid sinus syndrome (CSS) by maneuvers designed to induce generalized sympathetic activation after baroreceptor unloading (lower body negative pressure, LBNP) or direct peripheral adrenoreceptor stimulation via local administration of norepinephrine (NA). DESIGN: Subjects were identified with VD of CSS through diagnostic testing. SETTING: Research laboratory. PARTICIPANTS: Eleven young controls (YC) (mean age ± standard error of mean = 22.8 ± 0.7), eight elderly controls (EC) (72.6 ± 0.6), and eight elderly patients with VD (78.7 ± 1.7). MEASUREMENTS: Forearm arterial blood flow (FABF) was measured in the left and right arms by venous occlusion plethysmography. Measurements were performed during baseline conditions, LBNP (,20 mmHg), and intra-arterial NA infusion in the left brachial artery at three progressively increasing rates (60, 120, and 240 pmol/min). RESULTS: During LBNP, FABF significantly decreased in YC (baseline 3.61 ± 0.30 vs ,20 mmHg 2.96 ± 0.24 mL/100 g/min, P = .030) and EC (4.05 ± 0.74 vs 3.69 ± 0.65 mL/100 g/min, P = .033) but increased in elderly patients with VD (3.65 ± 0.60 vs 4.54 ± 0.80 mL/100 g/min, P = .020). During NA infusion, a significant forearm vasoconstriction occurred in YC (FABF left:right ratio 1.00 ± 0.05 at baseline; 0.81 ± 0.08 at 60 pmol/min, P = .034; 0.81 ± 0.05 at 120 pmol/min, P < .001; 0.72 ± 0.04 at 240 pmol/min, P < .001), whereas no significant FABF changes were observed in EC (1.04 ± 0.06; 0.96 ± 0.07, P = .655; 0.89 ± 0.10, P = .401; 0.94 ± 0.10, P = .590) or elderly patients with VD (1.04 ± 0.06; 1.16 ±0 .10, P = .117; 1.04 ± 0.08, P = .602; 1.11 ± 0.10, P = .305). CONCLUSION: VD of CSS is associated with a paradoxical vasodilatation during LBNP and an impairment of peripheral ,-adrenergic responsiveness, which may be age-related. [source] Doppler studies of the ovarian venous blood flow in the diagnosis of adnexal torsionJOURNAL OF CLINICAL ULTRASOUND, Issue 8 2009Khatib Nizar MD Abstract Purpose. To evaluate the role of ovarian Doppler studies in diagnosing adnexal torsion. Methods. We included in that study all patients who had an adnexal mass with clinical symptoms of intermittent lower abdominal pain and were hospitalized for at least 48 hours of observation. Our protocol included: measurements of the size of the adnexal mass, presence or absence of ovarian edema, presence or absence of adnexal vascularity, presence or absence of ovarian artery flow, presence or absence of ovarian venous flow, pattern of ovarian venous flow. The ovarian artery and vein were sampled just above and lateral to the adnexa. Sensitivity, specificity, and positive and negative predictive values in the diagnosis of adnexal torsion were calculated for each of the gray-scale and Doppler sonographic (US) findings. Results. One hundred and ninety-nine patients presented with adnexal mass and intermittent lower abdominal pain. Sensitivity and specificity of tissue edema, absence of intra-ovarian vascularity, absence of arterial flow, and absence or abnormal venous flow in the diagnosis of adnexal torsion were: 21% and 100%, 52% and 91%, 76% and 99%, and 100% and 97%, respectively. All patients with adnexal torsion had absent flow or abnormal flow pattern in the ovarian vein. In 13 patients, the only abnormality was absent or abnormal ovarian venous flow with normal gray-scale US appearance and normal arterial blood flow. Of these 13 patients, 8 (62%) had adnexal torsion or subtorsion. Conclusion. Abnormal ovarian venous flow may be the only abnormal US sign observed during the early stage of adnexal torsion. © 2009 Wiley Periodicals, Inc. J Clin Ultrasound 2009 [source] Assessing arterial blood flow and vessel area variations using real-time zonal phase-contrast MRIJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 3 2006Markus Oelhafen PhD Abstract Purpose To measure peripheral artery function using a real-time phase-contrast (PC)-MRI sequence with tailored image-processing algorithms for flow computation. Materials and Methods An approach to real-time flow measurements was developed based on two-dimensional spatially selective excitation pulses and consecutive tailored processing of the data to derive blood flow and vessel area variations. The data acquisition strategy allows for flow measurements at high spatial and temporal resolutions of 1 mm2 and 50 msec, respectively. In postprocessing the vessel area is automatically extracted using correlation measures in conjunction with morphological image operators. By means of in vitro and in vivo validations, it is shown that the current methods provide accurate and reproducible measurements of flow and vessel area variations. Results In vitro the comparison between the lumen area measured with the presented method and the values obtained by calliper gauge measurement showed a difference of 3.4% ± 3.4% (mean ± 2 SD). Similarly, the comparison between the stroke volumes determined with the presented method and by stopwatch and bucket measurements yielded a difference of 6.1% ± 2.1%. In vivo the results from the real-time measurements for lumen area and stroke volume were compared with those from a gated PC-MRI technique with differences of 4.8% ± 14% and 3.0% ± 24.7%, respectively. Conclusion The presented method constitutes a reliable tool set for quantifying the variations of blood flow and lumen area in the superficial femoral artery during reactive hyperemia and for studying their correlation with cardiovascular risk factors. J. Magn. Reson. Imaging 2006. © 2006 Wiley-Liss, Inc. [source] Successful management of uterine arteriovenous malformation by ligation of feeding artery after unsuccessful uterine artery embolizationJOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 1 2009Daisaku Yokomine Abstract Uterine arteriovenous malformation (AVM) is a rare and potentially life-threatening disease. The present report describes a postmenopausal patient with uterine AVM manifesting recurrent, massive genital bleeding. Uterine artery embolization (UAE) was scheduled before hysterectomy, but UAE was unsuccessful due to the dilated, tortuous internal iliac arteries, and extremely rapid arterial blood flow. Hysterectomy appeared to carry a potential risk of massive blood loss due to multiple dilated vessels around the uterine corpus and cervix. Therefore, six arteries feeding the uterus were surgically ligated. At 10 months after the operation there have been no episodes of atypical genital bleeding. [source] Effect of maternal fasting on uterine arterial blood flowJOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 2 2007Hisham M. Mirghani Abstract Aim:, To determine the effect maternal diet pattern on the uterine artery Doppler flow velocimetry. Methods:, This is a cross-sectional observational study. The uterine artery Doppler flow velocimetry was measured between 20 and 24 weeks' gestation in healthy pregnant women observing Ramadan. For each fasting mother, a non-fasting healthy pregnant woman was recruited as a control. Maternal blood glucose level was measured. Results:, A total of 106 pregnant women were studied. The mean hours since last oral intake were significantly longer, and the maternal glucose level was significantly lower in the study group than in the control group. The Mean (95% CI) of the uterine artery pulsatility index, resistance index, peak systolic velocity, end diastolic velocity and systolic/diastolic ratio was similar in both groups. Conclusion:, Maternal fasting is not associated with significant changes in the uterine artery Doppler flow velocimetry. [source] Recombinant activated factor VII efficacy and safety in a model of bleeding and thrombosis in hypothermic rabbits: a blind studyJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 2 2007A. GODIER Summary.,Background:,Recombinant activated factor VII (rFVIIa) is increasingly used to secure hemostasis in hemorrhagic situations in trauma and surgical patients. Hypothermia is often observed in these clinical settings. Objective:,To study the efficacy and safety of rFVIIa in hypothermia in a rabbit model of bleeding and thrombosis. Methods:,Sixty-nine rabbits were anesthetized, ventilated and monitored for blood pressure, temperature and carotid flow. The Folts model was used: a stenosis (75%) and an injury were carried out on the carotid artery, inducing thrombosis. Blood flow decreased as thrombus size increased until the pressure gradient was such that the thrombus was released and local arterial blood flow was suddenly restored. This is known as a cyclic flow reduction (CFR). After counting baseline CFRs during a 20-min period (P1), rabbits were randomized blindly to one of four groups: normothermic (NT) placebo or rFVIIa (150 ,g kg,1), hypothermic (HT) (34 °C) placebo or rFVIIa. Then CFRs were recorded over a second period (P2). At the end of the experiment, a hepato-splenic section was performed and the amount of blood loss was recorded. After each period, the following were measured: ear immersion bleeding time (BT), hemoglobin, platelet count, prothrombin time (PT), activated partial thromboplastin time (aPTT) and fibrinogen. Results:,Hypothermia increased BT and blood loss. These effects were reversed by rFVIIa. In NT rabbits, rFVIIa shortened BT but did not reduce blood loss. rFVIIa-treated rabbits bled similarly regardless of temperature. The incidence of CFRs was higher in treated than placebo animals regardless of temperature. rFVIIa decreased PT and aPTT without modifying platelet count or fibrinogen level. Conclusion:,Hemostatic efficacy of rFVIIa was maintained in hypothermia. However, the number of CFRs was higher in the rFVIIa-treated group than in the placebo groups, whether for NT or HT rabbits. [source] Alteration of urothelial-mediated tone in the ischemic bladder: Role of eicosanoids,NEUROUROLOGY AND URODYNAMICS, Issue 3 2004Kazem M. Azadzoi Abstract Aims Previously we showed that ischemia alters bladder smooth muscle contractility in the rabbit. This study investigates the role of urothelium and eicosanoid-release in ischemic bladder smooth muscle instability. Materials and Methods Male New Zealand white rabbits were divided into treated (n,=,12) and age-matched control (n,=,10) groups. The treated group underwent balloon endothelial injury of the iliac arteries, and then received 4 weeks of cholesterol diet, followed by 4 weeks of regular diet. The control group received a regular diet for 8 weeks. After 8 weeks, blood flow for both the iliac arteries and the bladder as well as bladder oxygen tension were recorded. In one-half of each ischemic and control bladder, the urothelium was removed. Bladder tissues were processed for organ bath and enzyme-immunoassay (EIA) of prostaglandins (PGs) and leukotrienes (LTs). Results A significant decrease in iliac arterial blood flow, bladder wall blood flow, and bladder oxygen tension was found in the treated group. Bladder ischemia increased the frequency and amplitude of baseline spontaneous smooth muscle contractility. Ischemic tissues with urothelium (Uro+) demonstrated significant increases in the contractile response to electrical field stimulation (EFS) and carbachol relative to control Uro+ tissues. Urothelial removal increased smooth muscle contraction in the control tissues but had no significant effect in the ischemic/hypoxic tissues. Contraction of control tissues without urothelium (Uro,) was similar to contraction of ischemic Uro+ tissues. Contractions of ischemic Uro+ and control Uro, tissues were unchanged after treatment with the cyclooxygenase (COX) inhibitor indomethacin, while they were significantly reduced by the 5-lipoxygenase (5-LO) inhibitor NDGA. EIA showed no change in PGs release from the ischemic urothelium, but significant increase in PGF2-, and thromboxane A2 release from the ischemic suburothelial tissue. Ischemia increased the release of LTB4, LTC4, and LTE4 from both urothelium and suburothelial tissue. Conclusions Our studies suggest loss of urothelial-mediated tone and LTs-mediated smooth muscle instability in the chronically ischemic/hypoxic bladder. Neurourol. Urodynam. 23:258,264, 2004. Published 2004 Wiley-Liss, Inc. [source] Reversal Blood Flow Component as Determinant of the Arterial Functional Capability: Theoretical Implications in Physiological and Therapeutic ConditionsARTIFICIAL ORGANS, Issue 3 2009Daniel Bia Abstract In several physiological, pathological, and therapeutic circumstances, the arterial blood flow is acutely modified, increasing, in some vascular segments the reversal (SSR) and oscillatory (SSO) components of the shear stress. Recently, in an in vivo model we found a relationship between acute changes in SSR and SSO, and variations in the arterial viscoelasticity. As the arterial viscoelasticity and diameter are the main determinants of the arterial buffering (BF) and conduit (CF) functions, changes in those functions could be expected associated with variations in SSR and SSO. The aim was to analyze the association between acute increases in SSR and SSO, and changes in the aortic CF and BF. Aortic flow, pressure, and diameter were measured in 16 sheep under basal and high reversal and oscillatory flow conditions (high SSR and SSO). Aortic BF and CF were quantified, and their potential association with the SSR and SSO components were analyzed. During high reversal flow rate conditions, a smooth muscle contraction-pattern was evidenced, with an increase in BF and a decrease in CF. Changes in BF and CF were associated with the changes in SSR and SSO. The acute effects on the arterial wall biomechanics of variations in SSR and SSO could contribute to comprehend their chronic effects, and the meaning of the acute vascular effects of changes in SSR and SSO would depend on the situation. Increases in SSR and SSO could be associated with smooth muscle tone increase-dependent changes in arterial BF and CF. [source] Retinal vascular findings and penile cavernosal artery blood flowBJU INTERNATIONAL, Issue 9 2003Y. Kawanishi Authors from Japan attempt to correlate retinal vascular changes with cavernosal arterial blood flow. They studied patients with erectile dysfunction, but excluded patients with previous pelvic surgery, pelvic injury or diabetes. They found that penile changes can be anticipated from retinal vascular changes seen on fundoscopy. OBJECTIVE To assess the correlation between retinal vascular findings and penile cavernosal arterial blood flow, as it is probable that systemic atherosclerotic vascular disease is important in male erectile dysfunction (ED), and being systemic, it might be possible to evaluate the extent of atherosclerosis from retinal vascular findings. PATIENTS AND METHODS The study included 75 patients with ED; any with a history of pelvic injury, pelvic surgery, or diabetes mellitus were excluded. All patients gave fully informed consent. Ocular fundus photographs were taken with an automatic-focus fundus camera under amydriatic conditions. Three ophthalmologists, unaware of the patients' detailed data, evaluated the photographs using Hyman's classification to evaluate retinal vascular findings. Blood flow in the penile cavernosal artery was measured with colour Doppler ultrasonography, and the peak systolic velocity used as a haemodynamic variable. Correlations among the peak systolic velocity, retinal vascular findings and vascular risk factors (including hypertension, age, cigarette smoking, and hyperlipidaemia) were investigated using multivariate analysis. RESULTS Of the 75 patients, 72 (96%) had both right and left retinal vascular images of sufficient quality for evaluation; 37 were classified as normal and 35 as Grade I, while no patient was Grade II. From a logistic regression multivariate analysis, the peak systolic velocity was the only significant factor correlating with retinal vascular findings, with an odds ratio of 3.34. In contrast, hypertension, age, cigarette smoking and hyperlipidaemia did not correlate significantly with the retinal vascular findings. Similarly, the retinal vascular finding was the only significant factor correlating with the peak systolic velocity of cavernosal blood flow (odds ratio 3.28) and again hypertension, age, cigarette smoking and hyperlipidaemia were not significant factors. CONCLUSIONS These findings support the assumption that penile erectile function is one of the diseases of atherosclerosis, and emerges nearly simultaneously with retinal vascular disease. It is possible to predict penile arterial conditions in patients with ED from their retinal vascular findings. Thus, amydriatic fundoscopy, a simple practical examination, may be helpful for primary physicians in diagnosing and treating ED. [source] Effect of graded leg cycling on postischaemic forearm blood flow in healthy subjectsCLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 1 2008Marc Charles Summary This study assessed in healthy subjects, the effect of leg cycling on the forearm vascular responses to ischaemia to confirm previous results showing that exercise-induced sympathetic activation during leg cycling reduced postischaemic forearm hyperaemia. Seven young healthy subjects performed two bouts of cycling exercises at 50% and 80% of their maximal aerobic capacity (Ex50, Ex80 respectively) during which forearm arterial blood flow was successively occluded for 40, 90 and 180 s. Control forearm blood flow (FBF) and postischaemic forearm blood flow (pi-FBF) measured at the release of arterial occlusions were assessed using plethysmography. Digital arterial pressure was continuously monitored allowing calculation of control and postischaemic forearm conductance (FC and pi-FC respectively). At rest, pi-FBF increased with the duration of ischaemia (5 ± 1, 19 ± 3, 29 ± 3, 31 ± 4 ml min,1 100 ml,1 after 0, 40, 90 and 180 s of ischaemia respectively). During Ex50, FBF and pi-FBF did not change significantly although pi-FC was significantly reduced (,pi-FC = ,39%, ,33%, ,27% for 40, 90, 180 s of ischaemia respectively). During Ex80, there was a further dramatic decrease in pi-FC (,53%, ,66%, ,62% from rest) and pi-FBF were largely blunted (13 ± 4 versus 19 ± 3, 14 ± 4 versus 29 ± 3, 17 ± 5 versus 31 ± 4 ml min,1 100 ml,1). These results demonstrated that forearm responses to ischaemia depended on leg activities. It was suggested that exercise-induced sympathetic activation may have interfered on local vasodilatation because of ischaemia. [source] | |||||||||||||||||||