Nonsurgical Extracardiac Vascular Shunts in the Thorax: Clinical and Imaging Characteristics

Martínez-Jiménez, Santiago; Heyneman, Laura E.; McAdams, H. Page; Jasinowodolinski, Dany; Rossi, Santiago E.; Restrepo, Carlos S.; Washington, Lacey

doi:10.1148/rg.e41

Cited by 13 publications

(8 citation statements)

References 65 publications

(95 reference statements)

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“…Numerous extravascular shunts, both L-R and R-L, occur as congenital defects in humans (Martinez-Jimenez et al, 2010). For example, the ductus arteriosus is a blood vessel connecting the base of the pulmonary artery to the proximal descending aorta in birds and mammals that provides a foetal R-L shunt, presumably conserving cardiac energy by reducing blood perfusion of the non-functional developing lungs (Bergwerff, DeRuiter, & Gittenberger-de Groot, 1999;Dzialowski, 2018).…”

Section: (B) Extracardiac Shuntsmentioning

confidence: 99%

Cardiovascular shunting in vertebrates: a practical integration of competing hypotheses

2019

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This review explores the long‐standing question: ‘Why do cardiovascular shunts occur?’ An historical perspective is provided on previous research into cardiac shunts in vertebrates that continues to shape current views. Cardiac shunts and when they occur is then described for vertebrates. Nearly 20 different functional reasons have been proposed as specific causes of shunts, ranging from energy conservation to improved gas exchange, and including a plethora of functions related to thermoregulation, digestion and haemodynamics. It has even been suggested that shunts are merely an evolutionary or developmental relic. Having considered the various hypotheses involving cardiovascular shunting in vertebrates, this review then takes a non‐traditional approach. Rather than attempting to identify the single ‘correct’ reason for the occurrence of shunts, we advance a more holistic, integrative approach that embraces multiple, non‐exclusive suites of proposed causes for shunts, and indicates how these varied functions might at least co‐exist, if not actually support each other as shunts serve multiple, concurrent physiological functions. It is argued that deposing the ‘monolithic’ view of shunting leads to a more nuanced view of vertebrate cardiovascular systems. This review concludes by suggesting new paradigms for testing the function(s) of shunts, including experimentally placing organ systems into conflict in terms of their perfusion needs, reducing sources of variation in physiological experiments, measuring possible compensatory responses to shunt ablation, moving experiments from the laboratory to the field, and using cladistics‐related approaches in the choice of experimental animals.

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Section: (B) Extracardiac Shuntsmentioning

confidence: 99%

Cardiovascular shunting in vertebrates: a practical integration of competing hypotheses

2019

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“…When 2D sequences are used, each point must be predetermined and localized in separate acquisitions. In addition, by acquiring the entire volume (including the heart and large vessels) in a single acquisition, it is possible to accurately determine the presence of venous return abnormalities associated with ASD, detect flow in cases with suspected arterial ductus, and diagnose small flow extracardiac shunts (which until recently were diagnosed by CT based only on anatomical data) . Therefore, when flow must be measured at different locations—as occurs with shunts or coarctation of the aorta—the use of 4D‐flow MRI is even faster than 2D phase‐contrast MRI …”

Section: Discussionmentioning

confidence: 99%

Evaluation of Cardiac Shunts With 4D Flow Cardiac Magnetic Resonance: Intra‐ and Interobserver Variability

Ulloa

Vázquez

Vega

et al. 2020

Magnetic Resonance Imaging

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Background In the last decade, the capacity of magnetic resonance (MR) to evaluate congenital anomalies has improved substantially. To date, only a few studies have evaluated the value of 4D‐flow MRI in shunt assessments. Purpose/Hypothesis To assess the intra‐ and interobserver variability of 4D‐flow MRI in patients diagnosed with cardiac/extracardiac shunt. Secondarily, to assess the feasibility of directly measuring the shunt and to determine the prognostic correlation with the pulmonary‐to‐systemic (Qp/Qs) flow ratio. Study Type Retrospective. Population In all, 18 patients with cardiac shunt diagnosis. Field Strength/Sequence 1.5 T/4D phase‐contrast MRI. Assessment Pulmonary and systemic flows were measured at different locations to assess the internal consistency by two observers (twice by one, and once by the other). The Qp/Qs ratio was calculated. When feasible, direct flow was quantified by planimetry. Statistical Tests Spearman's rho correlation coefficient was used to assess the relationship between pulmonary/systemic flows measured at different levels and to compare the jet characteristics with prognostic data as right ventricle volume. Intra‐ and interobserver variability were determined by Bland–Altman plots and interobserver correlation. Results The most common shunt type (n = 10; 55.5%) was ostium secundum atrial septal defect (ASD). Direct visualization and quantification of shunt flow was possible in all studies. Pulmonary and systemic flows showed a strong correlation between these measures (Spearman's rho [r] of 0.872 and 0.899). The mean Qp/Qs ratio was 1.61(0.62). Mean flow rate was 2.01(1.68) l/min. The mean jet diameter was 11.88 (5.44) mm. Intraobserver (r = 0.97) and interobserver correlation (ICC = 0.95) for the Qp/Qs calculation were both excellent. Direct measurement of flow was strongly correlated (r = 0.98; ICC = 0.95). Correlation was strong between Qp/Qs and direct jet flow (r = 0.76 and 0.77), Qp/Qs and mean jet diameter (r = 0.79 and 0.94), and Qp/Qs with jet area (r = 0.77 and 0.94). Data Conclusion Measurement of the Qp/Qs ratio and direct shunt quantification using 4D‐flow MRI was feasible, and highly reproducible. Internal consistency was excellent, with low intra‐ and interobserver variability. Correlation between the Qp/Qs ratio, direct flow measurement, mean diameter, and jet area was strong. Evidence Level 3 Technical Efficacy Stage 2 J. Magn. Reson. Imaging 2020;52:1055–1063.

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“…8 The noninvasive diagnosis of this disease is based on thoracic multi-slice computed tomography, CT angiography, conventional angiography, magnetic resonance imaging, and radionuclide angiograms. 1,9 Although in the past open surgical correction was the gold-standard of treatment of this disease, nowadays interventional treatment is preferred, including balloon occlusion, coiling embolization, and other occlusion devices such as the Gianturco coil or, more recently, the Gianturco-Grifka Vascular Occlusion Device (Cook Inc.). [10][11][12] Despite all new therapeutic techniques, the treatment procedure depends on the origin of the AV fistula.…”

Section: Discussionmentioning

confidence: 99%

“…[1][2][3] Nowadays, arteriovenous fistulas are more frequently diagnosed, even in asymptomatic patients, during routine investigations, due to the improvement of imaging techniques. 4 Computed tomographic angiography (CTA) and conventional angiography are the goldstandard methods for diagnosing AV fistulas, being able to expose the convoluted pathways arising from abnormally connected vessels.…”

Section: Introductionmentioning

confidence: 99%

Case report. Multiple Mediastinal Arteriovenous Fistulas in a Patient with Myocardial Ischemia Symptoms and Tachy-Brady Arrhythmias

Kovács

Condrea²,

Rodean³

et al. 2017

Journal of Cardiovascular Emergencies

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Arteriovenous fistulas are abnormal vascular communications between the arterial and venous system and may lead to the development of arteriovenous shunts. These malformations are extremely rare, and their diagnosis can be difficult due to the lack of symptoms or the absence of hemodynamic consequences. In many cases, arteriovenous fistulas are discovered by chance. In this brief report, we present the case of a 31-year-old male with symptoms suggestive of angina pectoris, tachycardia-bradycardia syndrome and multiple episodes of syncope. Multi-slice computed tomography revealed the presence of multiple mediastinal fistulas connecting the aorta, superior vena cava, pulmonary veins and azygos system.

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Nonsurgical Extracardiac Vascular Shunts in the Thorax: Clinical and Imaging Characteristics

Cited by 13 publications

References 65 publications

Cardiovascular shunting in vertebrates: a practical integration of competing hypotheses

Cardiovascular shunting in vertebrates: a practical integration of competing hypotheses

Evaluation of Cardiac Shunts With 4D Flow Cardiac Magnetic Resonance: Intra‐ and Interobserver Variability

Case report. Multiple Mediastinal Arteriovenous Fistulas in a Patient with Myocardial Ischemia Symptoms and Tachy-Brady Arrhythmias

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