Home About us Contact
|
Home About us Contact | ||
|
|
||
Venous System (venous + system)
Kinds of Venous System Selected AbstractsSimple Access to the Coronary Venous System for Left Ventricular PacingPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 9 2003DANY E. SAYAD Implantation of the LV lead for biventricular pacing can be challenging, time consuming, and often requires extensive fluoroscopy time. A conventional diagnostic 5 Fr left Amplatz catheter was used to cannulate the coronary sinus in 15 consecutive patients undergoing implantation of a biventricular pacemaker. When the coronary sinus was cannulated, the proximal end of the Amplatz catheter was cut and the coronary sinus sheath was passed over the Amplatz catheter that was then removed. Coronary sinus cannulation was achieved in all 15 patients with a mean fluoroscopy time of3.34 ± 1.9 minutes. Subsequent implantation of a biventricular pacemaker was successful and free of complications in all the 15 patients. (PACE 2003; 26:1856,1858) [source] Abnormal venous and arterial patterning in chordin mutantsDEVELOPMENTAL DYNAMICS, Issue 9 2007Emmanučle C. Délot Abstract Classic dye injection methods yielded amazingly detailed images of normal and pathological development of the cardiovascular system. However, because these methods rely on the beating heart of diffuse the dyes, the vessels visualized have been limited to the arterial tree, and our knowledge of vein development is lagging. In order to solve this problem, we injected pigmented methylsalicylate resins in mouse embryos after they were fixed and made transparent. This new technique allowed us to image the venous system and prompted the discovery of multiple venous anomalies in Chord,/, mutant mice. Genetic inactivation of Chordin, an inhibitor of the Bone Morphogenetic Protein signaling pathway, results in neural crest defects affecting heart and neck organs, as seen in DiGeorge syndrome patients. Injection into the descending aorta of Chrd,/, mutants demonstrated how a very severe early phenotype of the aortic arches develops into persistent truncus arteriosus. In addition, injection into the atrium revealed several patterning defects of the anterior cardinal veins and their tributaries, including absence of segments, looping and midline defects. The signals that govern the development of the individual cephalic veins are unknown, but our results show that the Bone Morphogenetic Protein pathway is necessary for the process. Developmental Dynamics 236:2586,2593, 2007. © 2007 Wiley-Liss, Inc. [source] Interobserver agreement in the magnetic resonance location of cerebral vein and dural sinus thrombosisEUROPEAN JOURNAL OF NEUROLOGY, Issue 3 2007J. M. Ferro The interobserver variation in the magnetic resonance (MR) location of cerebral vein and dural sinus thrombosis (CVT) has not been previously reported. Four independent observers rated a convenience sample of 40 MR/MR angiographies to assess whether or not each dural sinus and major cerebral veins were occluded. Interobserver reliability was measured using , statistics. Interobserver agreement was comparable between the six pairs of raters. Agreement was excellent for thrombosis of the deep cerebral venous system (, = 1.00), cerebellar veins (, = 1.00), superior saggital sinus (, range: 0.82,1) and right jugular vein (, range: 0.84,0.95); good to excellent for the right transverse/sigmoid sinus (, range: 0.75,0.90) and the left jugular vein (, range: 0.65,0.85); moderate to excellent for the left lateral sinus (, range: 0.59,0.78) and the straight sinus (, range: 0.59,0.92); poor to good for the cortical veins (, range: 0.02,0.65). Agreement between observers varies with the location of CVT. It is good or excellent for most of the occluded sinus and veins, except for the cortical veins. This study suggests that information on the location of CVT can be reliably collected and used in multicentre studies. [source] Vascular and renal actions of brain natriuretic peptide in man: physiology and pharmacologyFUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 4 2005Alphons J.H.M. Houben Abstract During the last decade brain natriuretic peptide (BNP) has received increasing attention as a potential marker of cardiovascular disease. BNP may act as a compensating mechanism in cardiovascular diseases in order to reduce preload. However, the increase in endogenous BNP is often not sufficient to compensate for volume overload in diseases like established hypertension and heart failure. The reported hemodynamic and renal effects of BNP in man differ largely between studies, because of differences in design and doses of BNP employed. In the pharmacological range, BNP has clear blood pressure and afterload lowering effects, and in the kidney blood flow and filtration is increased with concomitant natriuresis and diuresis. While in the physiological range BNP does not affect blood pressure and reduces preload only, and induces natriuresis/diuresis without changes in renal blood flow and filtration. There is increasing evidence from vascular studies that BNP preferentially acts on the venous system resulting in preload reduction, in contrast to atrial natriuretic peptide which acts preferentially on the arterial system to reduce afterload. This review summarizes our current understanding of BNP, and discuss its regulation and mechanisms of action on the vasculature and the kidneys. [source] Retinoid signaling and cardiac anteroposterior segmentationGENESIS: THE JOURNAL OF GENETICS AND DEVELOPMENT, Issue 3 2001José Xavier-Neto Abstract Summary: Establishment of anterior,posterior polarity is one of the earliest decisions in cardiogenesis. Specification of anterior (outflow) and posterior (inflow) structures ensures proper connections between venous system and inflow tract and between arterial tree and outflow tract. The last few years have witnessed remarkable progress in our understanding of cardiac anteroposterior patterning. Molecular cloning and subsequent studies on RALDH2, the key embryonic retinaldehyde dehydrogenase in retinoic acid (RA) synthesis, provided the missing link between teratogenic studies on RA deficiency and excess and normal chamber morphogenesis. We discuss work establishing the foundations of our current understanding of the mechanisms of cardiac anteroposterior segmentation, the reasons why early evidence pointing to the role of RA in anteroposterior segmentation was overlooked, and the key experiments unraveling the role of RA in cardiac anteroposterior segmentation. We have also integrated recent experiments in a model of cardiac anteroposterior patterning in which RALDH2 expression determines anteroposterior boundaries in the heart field. genesis 31:97,104, 2001. © 2001 Wiley-Liss, Inc. [source] A fresh look at dry weightHEMODIALYSIS INTERNATIONAL, Issue 4 2008Jochen RAIMANN Abstract The concept of dry weight (DW) is central to dialysis therapy. The most commonly used definition of DW is the weight below which patients become hypotensive on dialysis. However, this definition is dependent on patient symptoms. A more rigorous definition of DW is the body weight at a physiological extracellular volume (ECV) state. Overhydration is an excess in ECV above that found in healthy subjects. In healthy subjects, within extremes of salt intake, ECV may vary between 280 and 340 mL/kg lean body mass. Sodium accumulation is one of the many consequences of renal failure; it results in increased water intake and an increase in ECV, and an accompanying rise in blood pressure with its clinical sequelae, most prominently cardiovascular and cerebrovascular diseases. Recently characterized endogenous digitalis-like factors which are released in response to ECV expansion have extended this traditional picture. Efforts to reduce a positive sodium balance include dietary counseling and avoidance of iatrogenic intradialytic sodium loading, such as dialysate sodium exceeding serum levels, sodium profiling, and intravenous saline. Excess ECV is predominantly located in the interstitial compartment and must be removed during dialysis therapy by ultrafiltration. During this process, interstitial fluid redistributes to the intravascular space via uptake in the capillary bed. In addition to that mechanism, we propose that increased lymphatic flow into the venous system contributes to plasma refilling. Both clinical and technical means are used to assess the presence of DW. Continuous segmental calf bioimpedance is a promising new technology for intradialytic DW diagnosis. [source] The petrosquamosal sinus in humansJOURNAL OF ANATOMY, Issue 6 2006Diego San Millán Ruíz Abstract This article provides a comprehensive description of the morphology of the human petrosquamosal sinus (PSS) derived from original observations made on 13 corrosion casts of the cranial venous system combined with routine clinical imaging studies in two patients. The PSS is not a rare finding in the adult human. In particular, continuous developments in imaging techniques have made radiologists become increasingly aware of this anatomical entity in recent years. The role of the PSS as a major encephalic drainage pathway and its potential implication in pathological conditions such as intracranial venous hypertension are discussed. [source] Ablation of Posteroseptal and Left Posterior Accessory Pathways Guided by Left Atrium,Coronary Sinus Musculature Activation SequenceJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 7 2008RÓBERT PAP M.D. Introduction: While some posteroseptal and left posterior accessory pathways (APs) can be ablated on the tricuspid annulus or within the coronary venous system, others require a left-sided approach. "Fragmented" or double potentials are frequently recorded in the coronary sinus (CS), with a smaller, blunt component from left atrial (LA) myocardium, and a larger, sharp signal from the CS musculature. Methods and Results: Forty patients with posteroseptal or left posterior AP were included. The LA,CS activation sequence was determined at the earliest site during retrograde AP conduction. Eleven APs (27.5%) were ablated on the tricuspid annulus (right endocardial), 9 (22.5%) inside the coronary venous system (epicardial), and 20 (50%) on the mitral annulus (left endocardial). A "fragmented" or double "atrial" potential was recorded in all patients inside the CS at the earliest site during retrograde AP conduction. Sharp potential from the CS preceded the LA blunt component (sharp/blunt sequence) in all patients with an epicardial AP, and in 10 of 11 (91%) patients with a right endocardial AP. Therefore, 18 of 19 (95%) APs ablated by a right-sided approach produced this pattern. The reverse sequence (blunt/sharp) was recorded in 19 of 20 (95%) patients with a left endocardial AP. Conclusion: During retrograde AP conduction, the sequence of LA,CS musculature activation,as deduced from analysis of electrograms recorded at the earliest site inside the CS,can differentiate posteroseptal and left posterior APs that require left heart catheterization from those that can be eliminated by a totally venous approach. [source] Temporary Occlusion of the Great Cardiac Vein and Coronary Sinus to Facilitate Radiofrequency Catheter Ablation of the Mitral IsthmusJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 6 2008ANDRE D'AVILA M.D. Introduction: Ablation of the mitral isthmus to achieve bidirectional conduction block is technically challenging, and incomplete block slows isthmus conduction and is often proarrhythmic. The presence of the blood pool in the coronary venous system may act as a heat-sink, thereby attenuating transmural RF lesion formation. This porcine study tested the hypothesis that elimination of this heat-sink effect by complete air occlusion of the coronary sinus (CS) would facilitate transmural endocardial ablation at the mitral isthmus. Methods: This study was performed in nine pigs using a 30 mm-long prototype linear CS balloon catheter able to occlude and displace the blood within the CS (the balloon was inflated with ,5 cc of air). Using a 3.5 mm irrigated catheter (35 W, 30 cc/min, 1 minute lesions), two sets of mitral isthmus ablation lines were placed per animal: one with the balloon deflated (CS open) and one inflated (CS Occluded). After ablation, gross pathological analysis of the linear lesions was performed. Results: A total of 17 ablation lines were placed: 7 with CS Occlusion, and 10 without occlusion. Despite similar biophysical characteristics of the individual lesions, lesion transmurality was consistently noted only when using the air-filled CS balloon. Conclusions: Temporary displacement of the venous blood pool using an air-filled CS balloon permits transmurality of mitral isthmus ablation; this may obviate the need for ablation within the CS to achieve bidirectional mitral isthmus conduction. [source] Percutaneous Suture Closure for Management of Large French Size Arterial and Venous PunctureJOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 4 2000TED FELDMAN M.D. Aortic valvuloplasty procedures have been limited principally by the occurrence of restenosis in this patient population. Once a decision has been made to proceed with aortic valvuloplasty, one of the next major concerns is management of the femoral artery puncture. For these procedures, 12Fr and 14Fr sheath introducers and prolonged compression with clamps or hemostatic devices have been necessary. Prolonged immobilization is painful for the elderly population in whom aortic valvuloplasty is used. The ability to use percutaneous suture closure to eliminate the need for manual compression, especially for clamp or hemostatic devices, has greatly improved patient tolerance for these procedures. A technique for preloading the suture closure device prior to insertion of a large bore sheath is the technique of choice to make this possible. Mitral valvuloplasty has faced fewer limitations and of course yields results equivalent to surgical commissurotomy in randomized trials. Improved management of the 14Fr femoral venous site has made outpatient treatment simpler. The technical approach necessary for success in the venous system uses contrast injections through the Perclose device marker port to insure that the device is properly positioned prior to deployment of the sutures. More rapid immobilization and simplified postprocedural management can be achieved using percutaneous suture closure for large caliber sheaths after mitral and aortic valvuloplasty. [source] MR-based visualization and quantification of three-dimensional flow characteristics in the portal venous systemJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 2 2010Zoran Stankovic MD Abstract Purpose: To evaluate the feasibility of time-resolved flow-sensitive MRI for the three-dimensional (3D) visualization and quantification of normal and pathological portal venous (PV) hemodynamics. Materials and Methods: Portal venous hemodynamics were evaluated in 18 healthy volunteers and 5 patients with liver cirrhosis. ECG- and adaptive respiratory navigator gated flow-sensitive 4D MRI (time-resolved 3D MRI with three-directional velocity encoding) was performed on a 3 Tesla MR system (TRIO, Siemens, Germany). Qualitative flow analysis was achieved using 3D streamlines and time-resolved particle traces originating from seven emitter planes precisely placed at anatomical landmarks in the PV system. Quantitative analysis included retrospective extraction of regional peak and mean velocities and vessel area. Results were compared with standard 2D flow-sensitive MRI and to the reference standard Doppler ultrasound. Results: Qualitative flow analysis was successfully used in the entire PV system. Venous hemodynamics in all major branches in 17 of 18 volunteers and 3 of 5 patients were reliably depicted with good interobserver agreement (kappa = 0.62). Quantitative analysis revealed no significant differences and moderate agreement for peak velocities between 3D MR and 2D MRI (r = 0.46) and Doppler ultrasound (US) (r = 0.35) and for mean velocities between 3D and 2D MRI (r = 0.41). The PV area was significantly (P < 0.01) higher in 3D and 2D MRI compared with US. Conclusion: We successfully applied 3D MR velocity mapping in the PV system, providing a detailed qualitative and quantitative analysis of normal and pathological hemodynamics. J. Magn. Reson. Imaging 2010;32:466,475. © 2010 Wiley-Liss, Inc. [source] Magnetic resonance portography using contrast-enhanced fat-saturated three-dimensional steady-state free precession imagingJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 2 2004Yasuo Amano MD Abstract Purpose To assess the feasibility of contrast-enhanced fat-saturated three-dimensional steady-state free precession (FIESTA) imaging for contrast-enhanced magnetic resonance (MR) portography. Materials and Methods Contrast-enhanced fat-saturated three-dimensional fast spoiled gradient-echo (SPGR) and FIESTA were performed as MR portography. In 10 cases, fat-saturated three-dimensional FIESTA was first performed and followed by fast SPGR, and the order of post-contrast imaging was reversed in the other 10 cases. Signal-to-noise ratios (SNRs) and contrast-to-noise ratios (CNRs) were estimated for portal and visceral veins on the source images. The visualization of portal vein was scored on three-dimensional MR portography. Portal venous system disorders were assessed using three-dimensional MR portography. Results The SNRs, CNRs, and visual assessment of portal and visceral veins were significantly higher in contrast-enhanced fat-saturated three-dimensional FIESTA than contrast-enhanced fat-saturated three-dimensional fast SPGR (P < 0.05). The contrast-enhanced fat-saturated three-dimensional FIESTA provided high venous signals even at 8 minutes after gadolinium injection. The abnormalities of portal venous system were well visualized with MR portography using contrast-enhanced fat-saturated three-dimensional FIESTA. Conclusion Contrast-enhanced fat-saturated three-dimensional FIESTA was valuable for MR portography, with flexible time window and high vascular signals. This imaging may allow for other post-contrast imaging options before portography and release patients from consecutive breath-holds. J. Magn. Reson. Imaging 2004;19:238,244. © 2004 Wiley-Liss, Inc. [source] Multidetector CT portal venography in evaluation of portosystemic collateral vesselsJOURNAL OF MEDICAL IMAGING AND RADIATION ONCOLOGY, Issue 1 2008A Agarwal Summary This essay shows the usefulness of multidetector CT angiography for evaluation of the splenoportal venous system, which is essential in the management of patients with portal hypertension and its complications, such as portal vein thrombosis. By providing scanning with reconstruction of thin axial source images and reformatting into thicker multiplanar reformats, multidetector CT can help to determine the extent and location of portosystemic collateral vessels in patients with portal hypertension and is probably the optimal imaging technique in this setting. [source] Microcirculatory Dysfunction in Chronic Venous Insufficiency (CVI)MICROCIRCULATION, Issue S1 2000MICHAEL JÜNGER ABSTRACT The elevated ambulatory pressure in the peripheral venous system of chronic venous insufficiency (CVI) patients manifests itself not only in the form of disturbed macrocirculation but also and particularly in microangiopathic changes. For this reason, it is closely correlated with trophic disorders of the skin and can ultimately lead to ulceration. Using microcirculation research techniques, we are able to provide clear evidence of a typical microangiopathy in chronic venous insufficiency. Fifty CVI patients in Widmer stages I, II, and III were examined with fluorescence video microscopy, intravital video capillaroscopy, transcutaneous oxygen partial pressure measurement, TcpO2 and laser Doppler flowmetry. The effects of compression therapy with individually fitted compression stockings on capillary morphology were studied over a period of 4 weeks in 20 CVI patients in Widmer stages I and II. The capillary pressure was measured during simulated muscle contraction using a servo-null micropressure system. We periodically drew blood from the dorsalis pedis vein and a brachial vein of 11 healthy test persons and 8 patients with stage III CVI during experimental venous hypertension in order to evaluate the expression pattern of leukocyte adhesion molecules involved in inflammation: LFA-1 (CD11a), Mac-1 (CD11b), p150,95 (CD11c), CD18, VLA-4 (CD49d), and L-selectin (CD62L). In the same patients, we used immunohistochemical methods to examine clinically unaffected skin and the skin near an ulcer, focusing on the adhesion molecules ICAM-1, VCAM-1, and E-selectin. The microangiopathic changes observed with worsening clinical symptoms include a decrease in the number of capillaries, glomerulus-like changes in capillary morphology, a drop in the oxygen content (tcpO2) of the skin, increased permeability of the capillaries to low-molecular-weight substances, increased laser Doppler flux reflecting elevated subcutaneous flow, and diminished vascular reserve. These microangiopathic changes worsen in linear proportion to the clinical severity of chronic venous insufficiency. In patients with venous ulcerations, the baseline expression of LFA-1 and VLA-4 on lymphocytes, Mac-1 expression on the myeloid cell line, and L-selectin expression on all three cell lines was not significantly different from that in healthy controls. During orthostatic stress, there was a significant reduction in the expression of L-selectin in blood cells collected at foot level in the controls (p = 0.002), but not in the patients. Clinical improvement by compression therapy was accompanied by an increase in the number of nutritive capillaries, while the diameter of the capillaries and the dermal papillae was reduced. When ulcers healed in a short period (<6 weeks), we observed a concomitant increase in the number of capillaries (p < 0.05). Microangiopathy appears before trophic disorders of the skin develop. Even trophically normal skin areas may have dilated nutritive capillaries, an early sign of disturbed skin perfusion. These changes represent a plausible explanation for the development and to recurrency tendency of venous ulcers. The reduced expression of lymphocytic L-selectin in healthy controls during the orthostatic stress test may be an indication that the cells are activated by venous stasis. Clinically effective therapeutic measures improve the impaired microcirculation of the skin in the ankle area. [source] Atrioventricular Nodal Tachycardia in a Patient with Anomalous Inferior Vena Cava with Azygos Continuation and Persistent Left Superior Vena CavaPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 10 2009MIGUEL A. ARIAS M.D., Ph.D. A 39-year-old female patient was referred for ablation of recurrent episodes of atrioventricular nodal reentrant tachycardia. A combination of an anomalous inferior vena cava with azygos continuation and a persistent left superior vena cava was discovered. A nonfluoroscopic navigation system was very useful for catheter ablation of the tachycardia in this unusual case of anomalous venous system of the heart. [source] Transfemoral Snaring and Stabilization of Pacemaker and Defibrillator Leads to Maintain Vascular Access During Lead ExtractionPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 3 2009AVI FISCHER M.D. Background: Lead extraction is an effective method for removing pacemaker and defibrillator leads and to obtain venous access when central veins are occluded. Objective: We report a series of patients who required lead extraction and preservation of vascular access requiring a vascular snare introduced from the femoral vein to provide traction on the lead. This technique allowed advancement of the extraction sheath beyond the level of vascular occlusion, preserving vascular access in all patients. Methods: All patients had peripheral contrast venography performed immediately prior to the procedure to identify the site(s) of venous occlusion. An extraction sheath was employed and with direct manual traction, the lead tip pulled free from the myocardial surface prior to advancement of the sheath beyond the occlusion. A transfemoral snare was used to grasp the distal portion of the lead and traction was used to immobilize the lead. Results: In all patients, transfemoral snaring of the leads was necessary to allow safe advancement of a sheath to open the occluded venous system. There were no complications in any of the patients. Conclusion: Our series demonstrates the simple and safe technique of transfemoral lead snaring to assist lead extraction and maintain vascular access in the setting of venous occlusion, when the distal lead tip pulls free of the myocardium before an extraction sheath is passed beyond the point of venous obstruction. [source] Importance of Anterograde Visualization of the Coronary Venous Network by Selective Left Coronary Angiography Prior To ResynchronizationPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 1 2007NICOLAS DELARCHE M.D. Background: Understanding of coronary anatomy is essential to the advancement of cardiac resynchronization therapy (CRT) techniques. We determined whether the difficulties associated with catheterization of the coronary sinus (CS) and its lateral branches could be overcome by a preliminary angiographical study of the coronary venous system carried out during a pre-operative coronary angiography with examination of venous return. Methods and Results: All patients were scheduled for an exploratory angiography procedure and indicated for CRT. Group A patients were implanted with a CRT device after a right arterial angiographical procedure while group B patients had a selective left angiogram including examination of venous return. Data analyzed in group B were: position of CS ostium, number and distribution of lateral branches, and ability to preselect a marginal vein suitable for catheterization. Subsequent device implantation was guided by these parameters. A total of 96 and 89 patients were included in groups A and B, respectively. Implantation success rates were not different (98% and 100%, respectively), but CS catheterization time was reduced in group B (6 minutes vs 4 minutes; P < 10,6) as well as total time required to position the left ventricular lead (25 minutes vs 15 minutes; P < 10,6), fluoroscopy exposure (7 minutes vs 5 minutes; P < 10,6), and volume of contrast medium required (45 mL vs 15 mL; P < 10,6). Conclusion: A coronary angiographical study, including examination of the coronary venous return prior to implantation of a CRT device, can simplify the device implant and allows patient-specific preselection of appropriate tools for the procedure. [source] Inhibition of Biventricular Pacemakers by Oversensing of Far-Field Atrial DepolarizationPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 3 2002IGOR LIPCHENCA LIPCHENCA, I., et al.: Inhibition of Biventricular Pacemakers by Oversensing of Far-Field Atrial Depo-larization. This report describes two patients who exhibited far-field oversensing of the P wave by the ventricular channel of a DDD biventricular pacemaker implanted for the treatment of congestive heart failure. Oversensing probably occurred secondary to slight displacement of the left ventricular lead in the coronary venous system. Long-term reliable pacing was restored by decreasing the sensitivity of the ventricular channel. [source] Liver retransplantation in an infant requiring cavoportal hemi transpositionPEDIATRIC TRANSPLANTATION, Issue 4 2004Deborah Verran Abstract:, Historically inability to achieve portal inflow to the liver allograft operatively was felt to be a contraindication to orthotopic liver transplantation (OLTx). Cavoportal hemi transposition has been utilized more recently in adult OLTx recipients but rarely in pediatric recipients. Here we report the case of a 10-month-old male with biliary atresia, who required urgent retransplantation with an in situ split cadaver donor allograft for failure of his first liver allograft from portal vein thrombosis. At the time of retransplantation, cavoportal hemi transposition was required to effect portal vein inflow to the allograft because of extensive thrombosis of the recipients portomesenteric venous system. [source] Hemodynamic changes with phenotype reversal during pregnancy in twin,twin transfusion syndromePRENATAL DIAGNOSIS, Issue 10 2004G. C. Meyberg-Solomayer Abstract Objectives We report an atypical case of twin,twin transfusion syndrome (TTTS) in monochorionic-diamniotic twins with arterio-arterial anastomoses in which the former donor became the recipient during pregnancy. Methods Serial sonographic monitoring was performed. Results There was a phenotype reversal in TTTS concerning growth and amniotic fluid ending at 27 weeks, with the dominance of the former smaller donor. Doppler sonography changed from absent enddiastolic flow of the donor to normal values in both twins. The new recipient showed transient ascites, the now smaller actual donor (former recipient) developed progressive cardiomegaly, hypertrophy of the myocardium and mitral and tricuspid insufficiency at 29 weeks. Doppler sonography in the new donor deteriorated to highly pathologic flow in the venous system, leading to cesarean section. The donor fetus died 12 h after delivery because of myocardial decompensation. The recipient did very well and was discharged 8 weeks later from the neonatology unit. Conclusion This atypical course shows the importance of serial sonographic monitoring in pregnancies with TTTS. Copyright © 2004 John Wiley & Sons, Ltd. [source] Asymptomatic lower extremity deep venous thrombosis resulting in fibula free flap failure,THE LARYNGOSCOPE, Issue 6 2009Adam S. Jacobson MD Abstract Objectives/Hypothesis: The successful harvest and transplant of a fibular flap depends on many factors, including healthy inflow and outflow systems. A contraindication to harvesting a fibular flap is disease of the lower extremity arterial system; therefore, preoperative evaluation of the arterial system is routine. Preoperative evaluation of the venous system is not routine, unless there is clinical suspicion of venous disease. Methods: Retrospective chart review. Results: Two cases of occult deep venous thrombosis (DVT) were encountered intraoperatively resulting in nontransplantable flaps. Conclusions: This finding represents a serious concern, and we believe that venous imaging should be considered in patients with significant risk factors for harboring an occult DVT. Laryngoscope, 2009 [source] Macroscopic Anatomy of the Great Vessels and Structures Associated with the Heart of the Ringed Seal (Pusa hispida)ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 3 2009H. Smodlaka Summary The ringed seal [Pusa (Phoca) hispida], as well as other seals, exhibits unique anatomical properties when compared to its terrestrial counterparts. In the ringed seal, the most conspicuous marine adaptation is the aortic bulb. This large dilatation of the ascending aorta is comparable to that found in other seal species and marine mammals. The branches of the ascending aorta (brachiocephalic trunk, left common carotid artery and left subclavian artery) are similar to those of higher primates and man. The peculiarities of the venous system are: three pulmonary veins, a pericardial venous plexus, a caval sphincter, a hepatic sinus with paired caudal vena cavae and a large extradural venous plexus. Generally, three common pulmonary veins (right, left and caudal) empty into the left atrium. The pericardial venous plexus lies deep to the mediastinal pericardial pleura (pleura pericardica) on the auricular (ventral) surface of the heart. The caval sphincter surrounds the caudal vena cava as it passes through the diaphragm. Caudal to the diaphragm, the vena cava is dilated (the hepatic sinus), and near the cranial extremity of the kidneys, it becomes biphid. The azygos vein is formed from the union of the right and left azygos veins at the level of the 5th thoracic vertebra. Cardiovascular physiological studies show some of these anatomical variations, especially of the venous system and the ascending aorta, to be modifications for diving. This investigation documents the large blood vessels associated with the heart and related structures in the ringed seal. [source] Arteries of the Hindfoot of the Llama (Lama glama)ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 5 2000G. Graziotti Summary The objective of this study was to describe the arterial distribution of the hindfoot of the llama (Lama glama). Ten adult llamas, preserved in 6% formalin solution at 0°C, were dissected. The arterial system was perfused with a solution of 14% coloured plaster; the venous system was perfused with a solution of 17% coloured industrial gelatine. Angiographies were also obtained. In the llama, the arterial distribution is of the saphenous type and this simple sort of irrigation could be used as a didactic model. The caudal branch of the saphenous artery divides into the small lateral plantar artery and the larger medial plantar artery, which continues as the plantar common digital artery III, and it is the main blood supply of the hindfoot. The dorsal pedal artery is underdeveloped and the perforating tarsal artery does not exist in this species. The plantar common digital artery III divides into the plantar proper digital II, III and IV. Branches from the plantar proper digital artery III supply the digits. We compared the arterial distribution of the hindfoot of the llama with that of other domestic animals including the one-humped camel (Camelus dromedarius). [source] Azoospermia and Sertoli-cell-only syndrome: hypoxia in the sperm production site due to impairment in venous drainage of male reproductive systemANDROLOGIA, Issue 5 2010Y. Gat Summary Sertoli-cell-only (SCO) syndrome, or germ cell aplasia, is diagnosed on testicular biopsy when germ cells are seen to be absent without histological impairment of Sertoli or Leydig cells. It is considered a situation of irreversible infertility. Recent studies have shown that varicocele, a bilateral disease, causes hypoxia in the testicular microcirculation. Destruction of one-way valves in the internal spermatic veins (ISV) elevates hydrostatic pressure in the testicular venules, exceeding the pressure in the arteriolar system. The positive pressure gradient between arterial and venous system is reversed, causing hypoxia in the sperm production site. Sperm production deteriorates gradually, progressing to azoospermia. Our prediction was that, if genetic problems are excluded, SCO may be the final stage of longstanding hypoxia which deteriorates sperm production in a progressive process over time. This would indicate that SCO is not always an independent disease entity, but may represent deterioration of the testicular parenchyma beyond azoospermia. Our prediction is confirmed by histology of the seminiferous tubules demonstrating that SCO is associated with extensive degenerative ischaemic changes and destruction of the normal architecture of the sperm production site. Adequate treatment of bilateral varicocele by microsurgery or by selective sclerotherapy of the ISV resumes, at least partially, the flow of oxygenated blood to the sperm production site and restored sperm production in 4 out of 10 patients. Based on our findings the following statements can be made: (i) SCO may be related in part of the cases to persistent, longstanding testicular parenchymal hypoxia; (ii) germ cells may still exist in other areas of the testicular parenchyma; and (iii) if genetic problems are excluded, adequate correction of the hypoxia may restore very limited sperm production in some patients. [source] Investigation and treatment of chronic venous ulcer diseaseANZ JOURNAL OF SURGERY, Issue 4 2001M. C. Stacey Introduction: The investigation and treatment of chronic venous ulceration continues to present many difficulties for the clinician. The uncertainties relate to the appropriate use of different forms of investigation and whether conservative treatment or surgical treatment should be used. Method: A comprehensive search was undertaken of published literature on venous ulceration. Results: The extent of investigations is largely determined by the type of treatment that the patient is either fit to undertake or is prepared to undertake. When conservative treatment only is to be used, detailed investigation of the venous system is not required. The role of surgery to the veins remains unproven in improving the healing of venous ulcers. Surgery to prevent ulcer recurrence has been demonstrated to be of benefit only in patients who have normal deep veins. Conclusions: Investigations performed on the venous system should be determined by the planned treatment. Many of the operations that have been performed on the venous system still remain unproven in providing a benefit to the healing of venous ulcers and in preventing venous ulcer recurrence. [source] Effect of breed on anatomy of portosystemic shunts resulting from congenital diseases in dogs and cats: a review of 242 casesAUSTRALIAN VETERINARY JOURNAL, Issue 12 2004GB HUNT Objective To evaluate the effect of species and breed on the anatomy of portosystemic vascular anomalies in dogs and cats. Design Retrospective study of 233 dogs and nine cats presenting to the University Veterinary Centre, Sydney. Methods Case records were evaluated for breed, sex, age, anatomical and histological diagnosis. Cases were included when a portosystemic vascular anomaly resulted from a congenital or developmental abnormality of the liver or portal venous system. Results Disease conditions included single congenital portosystemic shunt with patent portal vasculature (214 dogs, nine cats), portal vein aplasia (nine dogs), multiple acquired shunts resulting from portal vein hypoplasia (seven dogs), biliary atresia (one dog) and microvascular dysplasia (one dog). One Maltese had a single, congenital shunt and multiple acquired shunts resulting from hepatic cirrhosis. Breeds that were significantly over-represented included the Maltese, Silky Terrier, Australian Cattle Dog, Bichon Frise, Shih Tzu, Miniature Schnauzer, Border Collie, Jack Russell Terrier, Irish Wolfhound and Himalayan cat. Bichon Frise with shunts were significantly more likely to be female than male (12:2, P < 0.001). Two hundred and fourteen dogs (91.4%), and all cats, had shunts that were amenable to attenuation. Inoperable shunts occurred in 19 dogs (8.2%). Fifty six of 61 (92%) operable shunts in large breed dogs were intrahepatic, versus 10/153 (7%) in small breeds (P < 0.0001). Breeds that were not predisposed to portosystemic shunts were significantly more likely to have unusual or inoperable shunts than dogs from predisposed breeds (29% versus 7.6%, P < 0.0001). No significant relationship between breed and shunt type could be determined in cats. Conclusion Breed has a significant influence on shunt anatomy in dogs. Animals presenting with signs of portosystemic shunting may suffer from a wide range of operable or inoperable conditions. Veterinarians should be aware that unusual or inoperable shunts are much more likely to occur in breeds that are not predisposed to congenital portosystemic shunts. [source] Angioarchitecture of the venous and capillary system in heart defects induced by retinoic acid in mice,BIRTH DEFECTS RESEARCH, Issue 7 2009Anna Ratajska Abstract BACKGROUND: Corrosion casting and immunohistochemical staining with anti-alpha smooth muscle actin and anti-CD34 was utilized to demonstrate the capillary plexus and venous system in control and malformed mouse hearts. METHODS: Outflow tract malformations (e.g., double outlet right ventricle, transposition of the great arteries, and common truncus arteriosus) were induced in progeny of pregnant mice by retinoic acid administration at day 8.5 of pregnancy. RESULTS: Although control hearts exhibited areas in which capillaries tended to be oriented in parallel arrays, the orientation of capillaries in the respective areas of malformed hearts was chaotic and disorganized. The major branch of a conal vein in control hearts runs usually from the left side of the conus to its right side at the root of the pulmonary trunk and opens to the right atrium below the right auricle; thus, it has a curved course. On the other hand, a conal vein in malformed hearts courses from the left side or from the anterior side of the conus and tends to traverse straight upwards along the dextroposed aorta or along the aortopulmonary groove with its proximal part located outside of the heart. Other cardiac veins in outflow tract malformations are positioned in the same locations as in control hearts. CONCLUSIONS: We postulate that the changed location of the conal vein and disorganized capillary plexus result from malformed morphogenesis of the outflow tract and/or a disturbed regulation of angiogenic growth factor release from the adjacent environment. Birth Defects Research (Part A), 2009. © 2009 Wiley-Liss, Inc. [source] The effect of graduated compression stockings on blood velocity in the deep venous system of the lower limb in the postnatal periodBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 10 2007R Jamieson Venous thromboembolism (VTE) is the leading cause of maternal mortality in the UK and is also a major cause of long-term morbidity. Recent UK national guidelines recommend thromboprophylaxis, which includes the use of graduated compression stockings (GCS), for high-risk women to reduce the risk of VTE in both the antenatal and postpartum period. This study of 17 women examined the effects of GCS on the deep venous system in the immediate postpartum period and found a statistically significant reduction in the diameter of the common femoral vein (CFV) (pre- versus post stocking diameter: mean 10.39 mm [SD 2.09] versus mean 9.69 mm [SD 1.99]) and an increase in the rate of blood velocity in the CFV (pre- versus post stocking velocity: mean 10.0 cm/s [SD 2.7] versus 13.9 cm/s [SD 4.2]) 30 minutes after application of thigh length GCS in women 1 or 2 days following a singleton vaginal delivery at term. This confirms reduction in venous stasis in the deep venous system in the immediate postpartum woman by the use of GCS, supporting their use in improving venous function in this context. [source] Adrenergic mechanisms in canine nasal venous systemsBRITISH JOURNAL OF PHARMACOLOGY, Issue 1 2003Min Wang We investigated the adrenergic mechanisms of the two venous systems that drain the nasal mucosa, thereby their exact role in eliciting nasal decongestion. The action of endogenously released noradrenaline and exogenous adrenergic agonists on different segments of the nasal venous systems, i.e. collecting (LCV, SCV) and outflow (SPV) veins of posterior venous system, collecting (ACV) and outflow (DNV) veins of anterior venous system and venous sinusoids of the septal mucosa (SM), were studied. In vitro isometric tension of the vascular segments was measured. Transmural nerve stimulation (TNS) produced constriction in ACV, DNV and SM, primary constriction followed by secondary dilatation in LCV and SCV and dilatation in SPV. Tetrodotoxin (10,6M) abolished all responses. Phentolamine (10,6M), prazosin (10,6M) and rauwolscine (10,7M) inhibited the constriction in all venous vessels. Propranolol (10,6M), atenolol (10,6M) and ICI 118,551 (10,6M) inhibited the relaxation in SPV but not in LCV and SCV. Phenylephrine and clonidine constricted whereas dobutamine and terbutaline relaxed all venous vessels dose-dependently. These results indicate ,1 -, ,2 -, ,1 - and ,2 -adrenoceptors are present in both venous systems. TNS causes constriction of anterior venous system, venous sinusoids and posterior collecting veins primarily via postjunctional ,2 -adrenoceptors but relaxation of posterior outflow vein equally via postjunctional ,1 - and ,2 -adrenoceptors. The combined action of the two adrenergic mechanisms can reduce nasal airway resistance in vivo by decreasing vascular capacitance and enhancing venous drainage via the posterior venous system. British Journal of Pharmacology (2003) 138, 145,155. doi:10.1038/sj.bjp.0705020 [source] A prospective cohort study determining the prevalence of thrombotic events in children with acute lymphoblastic leukemia and a central venous line who are treated with L-asparaginase,CANCER, Issue 2 2003Results of the Prophylactic Antithrombin Replacement in Kids with Acute Lymphoblastic Leukemia Treated with Asparaginase (PARKAA) Study Abstract BACKGROUND Thrombotic events (TEs) are serious secondary complications in children with acute lymphoblastic leukemia (ALL) who receive L-asparaginase (ASP) therapy; however, the prevalence of TEs has not been established. The primary objective of the Prophylactic Antithrombin Replacement in Kids with Acute Lymphoblastic Leukemia Treated with Asparaginase (PARKAA) Study was to determine the prevalence of TEs. The secondary objective was to detect any association of TEs with the presence of congenital or acquired prothrombotic disorders. METHODS Children with ALL were screened for TEs at the end of ASP treatment using bilateral venograms, ultrasound, magnetic resonance imaging, and echocardiography. Symptomatic TEs were confirmed by appropriate radiographic tests. All tests were read by a blinded central adjudication committee. RESULTS Twenty-two of 60 children had TEs, a prevalence of 36.7% (95% confidence interval, 24.4,48.8%). TEs were located in the sinovenous system of the brain in 1 patient, the right atrium in 3 patients, and the upper central venous system in 19 patients. TEs detected by venography resulted in 1) 25,100% occlusion, with 1 in 3 patients showing occlusion of > 75% of the greatest vessel dimension, and 2) the presence of collaterals in 60% of patients, with 40% categorized as major. No children with TEs were positive for factor V Leiden or prothrombin gene 20201A, and four of eight children with antiphospholipid antibodies had a TE. CONCLUSIONS The prevalence of TEs is exceedingly high in this population, and it is likely that the extent of occlusion is likely clinically significant. No trend was seen toward an association between TEs and the presence of congenital prothrombotic disorders. A trend was seen toward an association between TEs and antiphospholipid antibodies. Carefully designed clinical trials of primary prophylaxis for the prevention of TEs are required in this patient population. Cancer 2003;97:508,16. © 2003 American Cancer Society. DOI 10.1002/cncr.11042 [source] | |||||||||||||||||||||||||||||||