Vein Connection Research Articles

Ultrasound-based topographic analysis of tributary vein connection with the saphenous vein during ambulatory conservative hemodynamic correction of chronic venous insufficiency

ObjectivePreoperative mapping of great saphenous vein (GSV) escape points to tributary veins (TVs) and targeted intervention of escape points may reduce recurrence rates of varicose veins (VVs) after endovascular treatment of saphenous veins and prevent saphenous nerve complications. The aim of this study was to perform an analysis of cartography after Doppler ultrasound mapping of escape points in patients with VVs and to suggest one point that may prevent recurrence and nerve complications. MethodsUltrasound assessment of VVs was performed from March 4, 2016, to July 15, 2016, specifically focusing on the locations of escape points from the saphenous vein to TVs. The collected data were reviewed retrospectively. The topographic distribution of escape points was as follows: from inguinal ligament to midthigh; from midthigh to knee; from knee to midcalf; and from midcalf to heel. ResultsThirty patients (41 legs) with VVs underwent ultrasound examination. All VVs were characterized by reflux at the GSV. Topographic analysis revealed a total of 79 escape points in all patients. The most common location for escape points was the third part of the leg (from knee to midcalf), where 65.8% of escape points were located; 82.3% of all escape points were located below the knee. The mean diameter of the GSV at 3 cm and 15 cm from the saphenofemoral junction was 6.8 ± 1.6 cm and 5.5 ± 1.5 cm, respectively. Mean diameter of TVs was 5.1 ± 1.9 cm. The diameter was not significantly different between saphenous veins and TVs. The mean number of escape points in each leg was 1.9 ± 1.0. ConclusionsMost escape points (65.8%) are located from knee to midcalf (third part of the leg), and 82.3% of all escape points are located below the knee. The diameter of TVs near the escape point is about 90% of that of the GSV. Thermal ablations of below-knee saphenous vein have potential nerve damage. Ablation of saphenous veins above the knee alone may result in residual shunting and formation of persistent reservoirs in TVs. These persistent reservoirs may be removed effectively with sclerotherapy or miniphlebectomy, especially trying to remove TVs near the escape point. Direct ligation of a TV near the escape point from the saphenous vein, just like saphenofemoral junction ligation, could be performed. These approaches may be able to prevent residual shunting and may reduce recurrence rates and nerve injury.

Long Segment Aplasia of the Great Saphenous Vein Associated with Short Saphenous Vein Connection: A Case Report

Localised hypoplasia or aplasia of the great saphenous vein (GSV) is not uncommon, with reports primarily describing limited area of hypoplasia/aplasia around the knee. Long segment of hypoplasia/aplasia extending along the thigh and distally to lower calf is rare. We report a case of an 81-year-old lady with long segment of the GSV aplasia depicted 3 cm distal to sapheno-femoral junction (SFJ), down to 5 cm above the right ankle with direct communication with the short saphenous vein (SSV).

Outcomes of Double-patch and Warden Techniques in Patients With Supracardiac Partial Anomalous Pulmonary Venous Connection

This study compared outcomes following the double-patch and Warden procedures for correcting partial anomalous connection of the right pulmonary veins to the superior vena cava. Eighty (80) patients, aged <18years old, and with partial anomalous connection of the right pulmonary veins to the superior vena cava were randomly assigned into double-patch method (n=40) and Warden procedure (n=40) groups. The median follow-up was 22.5 (range, 12-39) months. The primary endpoint was sinus node dysfunction at the mid-term follow-up period. No early or late mortality occurred. In the early postoperative period, sinus node dysfunction was observed in 27.5% and 5% of cases after double-patch correction and the Warden procedure, respectively (risk ratio, 5.50; 95% confidence interval, 1.30-23.25; p=0.01). At follow-up, sinus node dysfunction persisted in two (5%) patients after double-patch correction. All patients had normal sinus rhythm after the Warden procedure. No early or late pacemaker implantation occurred in either group. No patients had significant pulmonary veins or superior vena cava stenosis. The double-patch technique and Warden procedure both showed excellent early and mid-term results with no mortality and minimal morbidity. The Warden procedure was associated with less sinus node dysfunction in the early postoperative period than the double-patch technique. There was no significant between-group difference in sinus node dysfunction at the mid-term follow-up.

Restoration of wall shear stress in the cephalic vein during extreme hemodynamics

The surgical creation of an artery–vein connection via a Brachicephalic fistula (BCF) in patients with end stage renal disease (ESRD) provides a unique opportunity to study blood vessel response mechanisms to extreme hemodynamic conditions in relatively short timeframes. After BCF creation, the flow rate in the vein increases by an order of magnitude leading to separated flows and corresponding abnormally low, or negative, wall shear stress (WSS) in the curved arch segment of the cephalic vein. Locations of abnormally low WSS are shown to correlate with development of neointimal hyperplasia (NH) and subsequent stenosis. It is found that the stenosis, prior to a surgical intervention, restores the normal physiological WSS in the vein. As a result, this investigation provides evidence that the adaptation principle, known to apply in the arterial system, is also valid in the venous system. A novel graphical method is developed that combines clinical and computational data to assist in interpreting these physiological mechanisms including adaptation that lead to changes in vein geometry over time.

Ductus Venosus Agenesis and Fetal Malformations: Report of Four Cases

Background: The agenesis of the ductus venosus (DVA) is a rare condition with a variable prognosis that relies partly on the presence of associated conditions. Therefore, the prenatal evaluation should include a careful examination of fetal circulation, particularly the umbilical and portal venous malformations.Methods In this study, we describe four cases of DVA diagnosed at our institution. For each case, we access the patient’s files in order to extract the following information: gestational age, umbilical vein connection, pre-natal imaging findings, gestational age at delivery or at pregnancy termination, fetal outcomes, post-natal imaging findings, post-mortem findings and karyotype.Results From the four cases included, two were diagnosed in the first trimester and the other two cases in the second trimester of gestation. Prenatal ultrasound studies revealed an intrahepatic shunt in one case and an extrahepatic shunt in three cases. In one case, the karyotype was not performed, whereas the other three had a normal karyotype. Cardiac anomalies were found in three of the four fetuses. All but one case presented with extracardiac abnormalities. None of the cases developed hydrops. Two cases are currently alive and well, one termination of pregnancy occurred at 25 weeks of gestation and one case died at 14 days during surgical correction of a complex cardiac malformation.Conclusions Clinicians should be aware of different and important findings during the fetal examination, which can be indicative of a DVA, and, when suspected, serial revaluations should be scheduled in order to identify any malformation.

Unilateral pulmonary vein atresia of children: 4 cases report and literature review

Objective To summarize the clinical characteristics, imaging characteristics, treatment and prognosis of unilateral pulmonary vein atresia (UPVA) in children and to improve the clinician′s understanding of this disease. Methods The clinical data of 4 cases of UPVA from January 2014 to December 2016 in Department of Cardiology, Guangzhou Women and Children′s Medical Center were retrospectively analyzed, and 50 cases from reviews of PubMed, OVID and Elsevier in the international medical literature database and 4 cases in Wanfang database for the domestic report were reviewed.The clinical characteristics, diagnosis, treatment and prognosis of total of 58 cases were analyzed. Results Four patients, with an average age of 1.8 years (1.5-2.7 years), showing congenital UPVA in 3 patients and secondary UPVA in 1 patient.There was 1 case of left upper pulmonary vein atresia, 2 cases of left pulmonary vein atresia and 1 case of right pulmonary vein atresia.Three cases showed recurrent hemoptysis and recurrent cough occurred in 1 case.Three cases were complicated with congenital heart disease.There was one case underwent bronchial artery embolization, 1 case received pulmonary vein left atrium connection, and 2 cases received conservative treatment.All patients had been followed up for 1-3 years so far.The patient receiving pulmonary vein left atrium had been completely cured, and the patient receiving bronchial artery embolization showed no occurrence of hemoptysis but still showed recurrent cough hemoptysis.The patient with secondary UPVA had no obvious clinical symptoms, the other 1 case who rejected operation and received conservative treatment still had recurrent pulmonary infection, intermittent hemoptysis.The average age of 54 cases(40 cases with age ≤18 years old) from the literature reports was 13.76 years (8 days -43 years) in which 52 cases were diagnosed as congenital UPVA, while 2 cases were secondary UPVA.Twenty-seven cases were right pulmonary vein atresia, 22 cases were left pulmonary vein atresia, and 5 cases were other types.There were 94.4%(51/54 cases) of the patients having recurrent cough, pulmonary infection, 92.6%(50/54 cases) of the patients with exertional dyspnea and polypnea, 68.5%(37/54 cases) of the patients with hemoptysis and hematemesis.There were 50.0%(27/54 cases) of UPVA patients who were complicated with heart malformation.Different degrees of pulmonary hypertension were observed in 75.9%(41/54 cases) of children, and 35.2%(19/54 cases) of patients had pulmonary lymphatic dilatation.Pulmonary resection was performed in 25 cases, pulmonary vein left atrium connection was performed in 11 cases, bronchial artery embolization was performed in 7 cases, and conservative treatment was performed in 11 cases.After operation, most of the patients had good prognosis without obvious clinical symptoms or mild symptoms. Conclusions In clinical practice, if unexplained hemoptysis, recurrent lower respiratory tract infection, pulmonary consolidation, pulmonary dysplasia or pulmonary hypertension present, the possibility of UPVA should be considered.Early diagnosis and early bronchial artery embolization, reconstruction of the pulmonary vein and atrial connection and repair of the defect of heart, can improve the symptoms or cure the children and reduce the morta-lity significantly. Key words: Child; Pulmonary vein atresia; Unilateral; Hemoptysis; Pneumonia

‘Left Right Out’: A Rare Case of Left Superior and Inferior Anomalous Pulmonary Venous Return Diagnosed with Transoesophageal Echocardiography

We present the case of a 31-year-old woman who was referred to our institution for transoesophageal echocardiography to investigate the cause of right ventricular volume overload seen on transthoracic echocardiography, investigating exertional dyspnoea. On transoesophageal echocardiogram, close examination of the interatrial septum did not reveal any atrial septal defect. Similarly, the right superior and inferior pulmonary veins were unremarkable. However, the left superior and inferior pulmonary veins were noticeably absent. Careful observation of colour Doppler applied to the right atrium during the assessment of the inter-atrial septum revealed colour aliasing and increased flow velocity at the entry of the superior vena cava (SVC) into the right atrium. On further inspection, there was evidence of a communication to the SVC 3.6 cm above the connection with the right atrium, receiving flow from a confluence of the left-sided pulmonary veins. Cardiac magnetic resonance imaging confirmed the finding of anomalous left superior and inferior pulmonary veins draining into the SVC. The most common form of anomalous pulmonary venous connection is the connection of the left upper pulmonary vein to the left innominate vein. Less commonly, the right-sided pulmonary veins can drain into the SVC or the IVC (‘Scimitar syndrome’). Anomalous connection of both left-sided pulmonary veins is an extremely rare finding, and represents a very small proportion of anomalous drainage cases. This case demonstrates the value of simple and inexpensive transoesophageal echocardiography for the diagnosis of congenital heart disease in an era where there still remains high demand on cardiac MRI and computed tomography services.

Spectrum of atrial arrhythmias using the ligament of Marshall in patients with atrial fibrillation

The role of the ligament of Marshall (LOM) in patients with atrial fibrillation (AF) has not been well defined. The purpose of this study was to describe the role of the LOM in patients with AF and related arrhythmias. Fifty-six patients (mean age 63 ± 11 years; persistent AF in 48 [86%]; ejection fraction 0.49 ± 0.13; left atrial diameter 4.7 ± 0.6 cm) with LOM-mediated arrhythmias were included. A LOM-pulmonary vein (PV) connection was present in 18 patients (32%) and was eliminated with radiofrequency (RF) ablation at the left lateral ridge or crux (n = 12), at the mitral annulus (n = 3), or with alcohol/ethanol (EtOH) ablation of the vein of Marshall (VOM; n = 3). A LOM-mediated atrial tachycardia (AT) was present in 13 patients (23%). Thirty-one patients with refractory mitral isthmus conduction were referred for potential EtOH ablation. In the 6 patients in whom VOM was injected during perimitral reentry, EtOH resulted in slowing in 3 patients and termination in 1 patient. In others, EtOH infusion resulted in complete isolation of the left-sided PVs and left atrial appendage. Repeat RF and adjunctive EtOH ablation of the VOM tended to be more effective in creating conduction block across the mitral isthmus than RF ablation alone (P = .057). The LOM is responsible for a variety of arrhythmia mechanisms in patients with AF and atrial tachycardia. It may be ablated at any point along its course, at the mitral annulus, at the lateral ridge/PV antrum, and epicardially in the coronary sinus and the VOM itself. EtOH ablation of the VOM may be an adjunctive strategy in patients with refractory perimitral reentry.

Primary Pulmonary Vein Stenosis: Outcomes, Risk Factors, and Severity Score in a Multicentric Study

Primary pulmonary vein stenosis (PPVS) still carries a poor prognosis, and prognostic factors remain controversial. The aim of this study was to determine outcomes and prognostic factors after PPVS repair in the current era. Thirty patients with PPVS and a normal pulmonary vein (PV) connection operated on in 10 European/North American centers (2000-2012) were included retrospectively. A specific PVS severity score was developed based on the assessment of each PV. Studied end points were death, PV reoperation, and restenosis. A univariate and multivariate risk analysis was performed. The mean number of affected PVs per patient was 2.7 ± 1.1. Sutureless repair was used in 21 patients (70%), endovenectomy was used in 5 patients, and patch venoplasty was used in 4 patients. Overall PV restenosis, reoperation, and mortality occurred in 50%, 40%, and 30% of patients respectively. Freedom from mortality, reoperation, and restenosis at 8 years of follow-up was 70% ± 8%, 62% ± 8%, and 47% ± 9%, respectively. Restenosis and mortality rates after sutureless repair versus nonsutureless repair were 57% (n= 12 of 21) versus 33% (n= 3 of 9) (p= 0.42) for restenosis and 38% (n= 8 of 21) versus 11% (n= 1 of 9) (p= 0.21) for mortality. Patients selected for a sutureless technique were younger and smaller and had more severe disease before operation. A postoperative high PVS score and pulmonary hypertension 1 month after the operation were independent risk factors for restenosis (hazard ratio [HR], 1.34; p= 0.002 and HR, 6.81; p= 0.02, respectively), reoperation (HR, 1.24; p= 0.01 and HR, 7.60; p= 0.02), and mortality (HR, 1.39; p= 0.01 and HR, 39.5; p= 0.008). Primary PVS still has a guarded prognosis in the current era despite adoption of the sutureless technique. Postoperative pulmonary hypertension and severity of disease evaluated by a new severity score are independent prognostic factors regardless of surgical technique.

Role of four-dimensional echocardiography with high-definition flow imaging and spatiotemporal image correlation in detecting fetal pulmonary veins.

Prenatal diagnosis of fetal total anomalous pulmonary vein connection (TAPVC) remains challenging for most screening sonographers. The purpose of this study was to evaluate the use of four-dimensional echocardiography with high-definition flow imaging and spatiotemporal image correlation (4D-HDFI) in identifying pulmonary veins in normal and TAPVC fetuses. We retrospectively reviewed and performed 4D-HDFI in 204 normal and 12 fetuses with confirmed diagnosis of TAPVC. Cardiac volumes were available for postanalysis to obtain 4D-rendered images of the pulmonary veins. For the normal fetuses, two other traditional modalities including color Doppler and HDFI were used to detect the number of pulmonary veins and comparisons were made between each of these traditional methods and 4D-HDFI. For conventional echocardiography, HDFI modality was superior to color Doppler in detecting more pulmonary veins in normal fetuses throughout the gestational period. 4D-HDFI was the best method during the second trimester of pregnancy in identifying normal fetal pulmonary veins. 4D-HDFI images vividly depicted the figure, course, and drainage of pulmonary veins in both normal and TAPVC fetuses. HDFI and the advanced 4D-HDFI technique could facilitate identification of the anatomical features of pulmonary veins in both normal and TAPVC fetuses; 4D-HDFI therefore provides additional and more precise information than conventional echocardiography techniques.

Imaging topography and morphometry of persistent left superior caval vein and its variations, detected on cardiac implantable electronic device implantation.

Persistent left superior caval vein (PLSCV) is a rare, anatomically diverse developmental anomaly of systemic veins. Clinically asymptomatic PLSCVs are detected incidentally during medical procedures that utilise systemic veins, such as cardiac implantable electronic device (CIED) placement, and whose successful completion depends on favourable morphometric parameters of these vessels. The aim of this paper was to present topography and morphometry of PLSCV variations encountered during CIED implantation procedures. We analysed a group of 5,010 patients for detection of PLSCV during de-novo CIED implantation procedures with transvenous lead placement in the years 2003-2015. PLSCVs were detected intraprocedurally based on venographic images illustrating the venous anomaly and its morphometric parameters, and were subsequently confirmed via postoperative diagnostics. PLSCVs were detected in 10 patients (mean age 66.0 ± 14.0 years; 5 females and 5 males), who constituted 0.2% of the analysed group. There were 6 cases of double superior vena cava (DSVC), 3 of which had a brachiocephalic vein (BCV) connection and did not have BCV bridging. Four patients with a PLSCV had right superior vena cava agenesis; this very rare variation is known as 'single PLSCV'. All of the detected PLSCV variations drained into the right atrium via the coronary sinus. Our data from a period of 13 years illustrate how rare the PLSCV-type venous anomaly is. The three distinct anatomical PLSCV types showed inter-individual morphometric variations. Due to asymptomatic nature of this anomaly, all cases were detected incidentally, during CIED implantation procedures.

Prenatal diagnoses of an uncommon isolated obstructed supracardiac total anomalous pulmonary venous connection

Introduction:Total anomalous pulmonary venous connection is an uncommon congenital heart disease. Four types are described based on the site of pulmonary venous drainage: supracardiac, cardiac, infradiaphragmathic, and mixed connection. In most cases of supracardiac type, the common venous confluence drains through an ascending left vertical vein into the brachiocephalic vein, right superior vena cava, and then into the right atrium. Anomalous connection of the pulmonary venous confluence directly to the right SVC, especially the obstructed form is an unusual and severe supracardiac variant. The prenatal diagnosis is challenging.Patient concerns:We present a case report of a fetus diagnosed with TAPVC at 23 gestational weeks.Diagnosis interventions:The 4-chamber view showed a small left atrium, with a “smooth” posterior wall and the absence of pulmonary vein connection. This is the first case of prenatally diagnosed isolated, obstructed supracardiac type with drainage directly into the right superior vena cava.Conclusion:The obstetrician and fetal cardiologist should be cautious at the direct and indirect echocardiographic signs of this condition. A prenatal diagnose of isolated, obstructed form is important for adequate planning of delivery and postnatal surgery in a tertiary center.

Clarifying the anatomy and physiology of totally anomalous systemic venous connection.

The description of totally anomalous systemic venous connection is limited to case reports. In this review, we seek to clarify anatomic, physiologic, and hemodynamic aspects of this extremely rare anomaly. We also present findings of two patients in whom connection of all the systemic veins was anomalous. In the first patient, with usual atrial arrangement, all systemic veins, including the coronary sinus, were connected anomalously to the morphologically left atrium. Limited left-to-right shunt across an atrial septal defect provided the only source of blood flow to the lungs. The diagnosis was established by saline contrast echocardiography and cardiac catheterization. Extreme hypoplasia of the right ventricle precluded corrective surgery, so we performed a bidirectional Glenn operation, along with atrial septectomy. The second patient had isomerism of the left atrial appendages, which creates problems in the definition in anatomic terms since the connection of the systemic veins can never be normal anatomically when both atriums possess a morphologically left appendage. Our patient, nonetheless, had all the systemic and pulmonary veins, connected to the left-sided atrial chamber which then connected to the left ventricle, thus producing hemodynamics of totally anomalous systemic venous connection. We propose an algorithm for evaluation of this hemodynamic combination and discuss management options. We also intend to clarify the potential differences between connection and drainage, with particular attention to the arrangement of atrial appendages. Even though the hemodynamics may be comparable, in anatomic terms, both systemic and pulmonary venoatrial connection will always be anomalous with isomeric atrial appendages.

Pulmonary vein obstruction after catheter ablation in a patient with partial anomalous pulmonary vein connection

A 75-year-old man with symptomatic atrial fibrillation was referred to our hospital for catheter ablation. Preprocedural echocardiogram showed mild-moderate degree mitral regurgitation (MR) and mild tricuspid regurgitation (TR) with transvalvular peak gradient (TVPG) of 27mmHg. The complete isolation of the pulmonary veins was performed by radiofrequency ablation, and the patient was kept in sinus rhythm after the procedure. However, the exertional dyspnea had gradually developed one year after the procedure. Echocardiogram showed severe TR with TVPG 60mmHg. MDCT showed partial anomalous pulmonary vein connection (PAPVC) of the left upper pulmonary vein and the occlusion of left lower pulmonary vein ostium: pulmonary venous flow of the left upper lung was drained into the brachiocephalic vein. The patient underwent surgical correction of PAPVC and annuloplasty of the mitral and tricuspid valve. Although it is unclear whether there is direct causal relationship between PAPVC and PV obstruction, anatomical evaluation of PVs is important in patients undergoing catheter ablation.<Learning objective: Partial anomalous pulmonary vein connection (PAPVC) is rare and often asymptomatic in adults. In the present case, pulmonary vein obstruction occurred after radiofrequency catheter ablation in a patient with PAPVC. Although pulmonary venous flow from only left upper lobe drained into the brachiocephalic vein before ablation, occlusion of the left lower pulmonary vein resulted in right heart failure one year after ablation.>

Nonaneurysmal Perimesencephalic Hemorrhage Is Associated with Deep Cerebral Venous Drainage Anomalies: A Systematic Literature Review and Meta-Analysis.

Mechanisms underlying bleeding in nonaneurysmal perimesencephalic SAH remain unclear. Previous investigators have suggested a relationship between nonaneurysmal perimesencephalic SAH and primitive venous drainage of the basal vein of Rosenthal. We performed a meta-analysis to evaluate the relation between primitive basal vein of Rosenthal drainage and nonaneurysmal perimesencephalic SAH. We performed a comprehensive literature search of all studies examining the prevalence of primitive basal vein of Rosenthal drainage in patients with aneurysmal SAH and nonaneurysmal perimesencephalic SAH. Data collected were primitive basal vein of Rosenthal drainage (direct connection of perimesencephalic veins into the dural sinuses instead of the Galenic system) in at least 1 cerebral hemisphere, normal bilateral basal vein of Rosenthal drainage systems, and the number of overall primitive venous systems in the nonaneurysmal perimesencephalic SAH and aneurysmal SAH groups. Statistical analysis was performed by using a random-effects meta-analysis. Eight studies with 888 patients (334 with nonaneurysmal perimesencephalic SAH and 554 with aneurysmal SAH) and 1657 individual venous systems were included. Patients with nonaneurysmal perimesencephalic SAH were more likely to have a primitive basal vein of Rosenthal drainage in at least 1 hemisphere (47.7% versus 22.1%; OR, 3.31; 95% CI, 2.15-5.08; P < .01) and were less likely to have bilateral normal basal vein of Rosenthal drainage systems than patients with aneurysmal SAH (18.3% versus 37.4%; OR, 0.27; 95% CI, 0.14-0.52; P < .01). When we considered individual venous systems, there were higher rates of primitive venous systems in patients with nonaneurysmal perimesencephalic SAH than in patients with aneurysmal SAH (34.9% versus 15.3%; OR, 3.90; 95% CI, 2.37-6.43; P < .01). Patients with nonaneurysmal perimesencephalic SAH have a higher prevalence of primitive basal vein of Rosenthal drainage in at least 1 hemisphere than patients with aneurysmal SAH. This finding suggests a venous origin of some nonaneurysmal perimesencephalic SAHs. A primitive basal vein of Rosenthal pattern is an imaging finding that has the potential to facilitate the diagnosis of nonaneurysmal perimesencephalic SAH.

Superficial middle cerebral vein connection to the cavernous sinus is not infrequent in brain arteriovenous malformations: an argument against their congenital origin?

The aim of this study was to test the hypothesis that the superficial middle cerebral vein (SMCV) is frequently absent or fails to connect with the cavernous sinus (CS) in the presence of brain arteriovenous malformations (AVMs), a frequently reported argument for the congenital origin of brain AVMs. The SMCV was retrospectively compared between patients with a brain AVM and a control group. The presence or absence of the SMCV, its direct or indirect connection to the CS and its termination in a laterocavernous sinus (LCS), paracavernous sinus (PCS), or directly in the CS was studied on digital subtraction angiography. One hundred twenty-five left or right side carotid angiograms from 70 patients with a brain AVM were compared to 125 angiograms from 74 controls. The SMCV was present in 88 (70.4%) cases in the brain AVM group and 96 (76.8%) cases in controls (p = 0.25). The SMCV was connected directly or indirectly to the CS in 65 (52%) cases in the brain AVM group and 65 (52%) cases in controls (p = 1). When comparing the subgroup of carotid angiograms ipsilateral to a supratentorial AVM, no statistically significant difference was found with controls. In three of six cases in which a SMCV drained an AVM, the vein terminated directly or indirectly in the CS. No difference of SMCV presence and direct or indirect connection to the CS was found between patients with AVM and a control group. SMCV anatomy does not support the congenital origin of brain AVMs.

Total anomalous pulmonary venous return

TAPVR typically presents in early infancy due to excessive pulmonary blood flow and mild cyanosis. Presentation is earlier when there is obstruction to pulmonary venous flow where neonates present with severe cyanosis and cardiogenic shock, surgical repair must be planned immediately. Mixing of well oxygenated blood through the anomalous connection of pulmonary veins with the systemic blood in the right atrium results in similar oxygen saturation in all cardiac chambers and arteries, therefore pre and post ductal oxygen saturations are equal. Increased blood flow across the right heart causes delay in closure of the pulmonary valve, presenting as fixed splitting of second heart sound as well as systolic flow murmur over the pulmonic region. Supra-cardiac drainage of anomalous pulmonary veins to the superior vena cava result in figure-eight or snow man appearance of the cardiac silhouette on CXR.

Transient pressure changes in the vertebral canal during whiplash motion – A hydrodynamic modeling approach

In vehicle collisions, the occupant׳s torso is accelerated in a given direction while the unsupported head tends to lag behind. This mechanism results in whiplash motion to the neck. In whiplash experiments conducted for animals, pressure transients have been recorded in the spinal canal. It was hypothesized that the transients caused dorsal root ganglion dysfunction. Neck motion introduces volume changes inside the vertebral canal. The changes require an adaptation which is likely achieved by redistribution of blood volume in the internal vertebral venous plexus (IVVP). Pressure transients then arise from the rapid redistribution. The present study aimed to explore the hypothesis theoretically and analytically. Further, the objectives were to quantify the effect of the neck motion on the pressure generation and to identify the physical factors involved. We developed a hydrodynamic system of tubes that represent the IVVP and its lateral intervertebral vein connections. An analytical model was developed for an anatomical geometrical relation that the venous blood volume changes with respect to the vertebral angular displacement. This model was adopted in the hydrodynamic tube system so that the system can predict the pressure transients on the basis of the neck vertebral motion data from a whiplash experiment. The predicted pressure transients were in good agreement with the earlier experimental data. A parametric study was conducted and showed that the system can be used to assess the influences of anatomical geometrical properties and vehicle collision severity on the pressure generation.

Control of vein network topology by auxin transport.

BackgroundTissue networks such as the vascular networks of plant and animal organs transport signals and nutrients in most multicellular organisms. The transport function of tissue networks depends on topological features such as the number of networks’ components and the components’ connectedness; yet what controls tissue network topology is largely unknown, partly because of the difficulties in quantifying the effects of genes on tissue network topology. We address this problem for the vein networks of plant leaves by introducing biologically motivated descriptors of vein network topology; we combine these descriptors with cellular imaging and molecular genetic analysis; and we apply this combination of approaches to leaves of Arabidopsis thaliana that lack function of, overexpress or misexpress combinations of four PIN-FORMED (PIN) genes—PIN1, PIN5, PIN6, and PIN8—which encode transporters of the plant signal auxin and are known to control vein network geometry.ResultsWe find that PIN1 inhibits vein formation and connection, and that PIN6 acts redundantly to PIN1 in these processes; however, the functions of PIN6 in vein formation are nonhomologous to those of PIN1, while the functions of PIN6 in vein connection are homologous to those of PIN1. We further find that PIN8 provides functions redundant and homologous to those of PIN6 in PIN1-dependent inhibition of vein formation, but that PIN8 has no functions in PIN1/PIN6-dependent inhibition of vein connection. Finally, we find that PIN5 promotes vein formation; that all the vein-formation-promoting functions of PIN5 are redundantly inhibited by PIN6 and PIN8; and that these functions of PIN5, PIN6, and PIN8 are independent of PIN1.ConclusionsOur results suggest that PIN-mediated auxin transport controls the formation of veins and their connection into networks.Electronic supplementary materialThe online version of this article (doi:10.1186/s12915-015-0208-3) contains supplementary material, which is available to authorized users.

Fracture patterns and fault development in the pelagic limestones of the Monte Conero Anticline (Italy)

Fracture patterns reflect the tectonic history of an area. By studying the characteristics of fracture patterns in outcrops it is feasible to reconstruct the sequence of events which helps to predict the fracture patterns in similar geological settings including fractured reservoirs and aquifers. This paper studies the fracture assemblages exposed in outcrops of the Monte Conero anticline, formed by two principal carbonate formations: the Maiolica and the Scaglia Rossa.Fieldwork measurements of fracture properties such as, orientation, length, aperture, microscope analysis of thin sections and crosscutting relationships, led to the recognition of a sequence of events and a fault development model that can explain the occurrence and morphology of breccia zones. The fractures occurring in the outcrops of Monte Conero, consist of veins, stylolites, joints, faults with breccias that occur both in elongated zones and in pockets. Veins and stylolites are the most occurring fractures and the highest fracture density occurs in outcrops along the coastline. Veins and stylolites are arranged in various geometries (e.g. en-echelon) which influence the connectivity with other fractures. Veins and stylolites play a fundamental role in the fault development process. Maiolica and Scaglia Rossa Fm. show different processes of fault development. The initial phase of fault development consists in both formations by shearing along pre-existing veins and the connection of veins by tail-joints.These tail joints break up the rock in between overlapping segments of sheared veins. In the Maiolica Fm, both joints and stylolites form at the tip of faults. The discontinuities at the tip of the faults are explained by high local stress concentrations. The relationships between fracture types observed at the micro-scale are similar to the ones observed at the outcrop-scale. Three different geological episodes were identified and each one is associated to a rotation of the directions of the principal stresses, the first episode formed a set of veins at high angle to bedding, the second episode formed sets of stylolites and the third episode caused slip along the pre-existing veins with formation of new sets of veins, stylolites, and breccia. The fault development process in Monte Conero is related to large and local scale tectonic events during which the veins, stylolites, joints and faults were formed and connected at different stages of the folding process, generating breccia zones. Breccia zones in faults are the only structures that contribute substantially to the secondary porosity of the low-porosity Conero's carbonate rocks.