- Tetralogy of Fallot Surgical Repair: Shunt Configurations, Ductus Arteriosus and the Circle of Willis. [Journal Article]
- CECardiovasc Eng Technol 2017; 8(2):107-119
- In this study, hemodynamic performance of three novel shunt configurations that are considered for the surgical repair of tetralogy of Fallot (TOF) disease are investigated in detail. Clinical experi...
In this study, hemodynamic performance of three novel shunt configurations that are considered for the surgical repair of tetralogy of Fallot (TOF) disease are investigated in detail. Clinical experience suggests that the shunt location, connecting angle, and its diameter can influence the post-operative physiology and the neurodevelopment of the neonatal patient. An experimentally validated second order computational fluid dynamics (CFD) solver and a parametric neonatal diseased great artery model that incorporates the ductus arteriosus (DA) and the full patient-specific circle of Willis (CoW) are employed. Standard truncated resistance CFD boundary conditions are compared with the full cerebral arterial system, which resulted 21, -13, and 37% difference in flow rate at the brachiocephalic, left carotid, and subclavian arteries, respectively. Flow splits at the aortic arch and cerebral arteries are calculated and found to change with shunt configuration significantly for TOF disease. The central direct shunt (direct shunt) has pulmonary flow 5% higher than central oblique shunt (oblique shunt) and 23% higher than modified Blalock Taussig shunt (RPA shunt) while the DA is closed. Maximum wall shear stress (WSS) in the direct shunt configuration is 9 and 60% higher than that of the oblique and RPA shunts, respectively. Patent DA, significantly eliminated the pulmonary flow control function of the shunt repair. These results suggests that, due to the higher flow rates at the pulmonary arteries, the direct shunt, rather than the central oblique, or right pulmonary artery shunts could be preferred by the surgeon. This extended model introduced new hemodynamic performance indices for the cerebral circulation that can correlate with the post-operative neurodevelopment quality of the patient.
- Double inferior vena cava with three shunts: a rare anomaly with important implications for surgeons. [Journal Article]
- FMFolia Morphol (Warsz) 2017; 76(2):307-311
- Inferior vena cava (IVC) is the largest single vein that collects systemic venous blood from the lower part of the body except the gut and drains into the right atrium. Double IVC is a rare anomaly i...
Inferior vena cava (IVC) is the largest single vein that collects systemic venous blood from the lower part of the body except the gut and drains into the right atrium. Double IVC is a rare anomaly in humans and usually is discovered incidentally during the interventional radiological procedures or routine cadaveric dissection. Here we report a rare case of unusual observations in an adult female Thai cadaver with a duplicated left IVC with three short venous shunts and a variant pattern of the hemiazygos vein. Also included in this case was the presence of unilateral double renal vein on the right kidney. This type of anatomic variation of the great vein has never been reported before. A detailed description of these variations is useful and essential for the surgeons during approaching the retroperitoneal region.
- Neonatal Cholestasis as Initial Presentation of Portosystemic Shunt: A Case Report. [Journal Article]
- JCJ Clin Exp Hepatol 2016; 6(4):331-334
- Congenital intrahepatic portosystemic shunts are rare in children. Portosystemic venous malformations are characterized by extreme clinical variability. We report a full-term 33-day-old male infant p...
Congenital intrahepatic portosystemic shunts are rare in children. Portosystemic venous malformations are characterized by extreme clinical variability. We report a full-term 33-day-old male infant presenting with neonatal jaundice. On physical examination, he had generalized icterus and the liver was palpable 3.5 cm below the right costal margin. He had no other symptoms. Laboratory tests showed AST 632 U/L, ALT 198 U/L, total bilirubin 12.1 mg/dL, conjugated bilirubin 10.2 mg/dL, alkaline phosphatase 753 U/L, GGT 47 U/L and glucose 67 U/L. Colour Doppler ultrasonography showed the left portal vein was more dilated than the right portal branch and communication with dilated left hepatic vein. There was no evidence of portal hypertension, heart failure, hepatopulmonary syndrome and encephalopathy during his hospital stay, so he was discharged from the pediatric department and his parents advised to attend monthly follow-up. Congenital portosystemic shunts are rarely observed in the childhood period.(1) Depending on anatomic characteristics they may be intrahepatic or extrahepatic.(2) Intrahepatic portosystemic shunts (PSS) are observed between the portal vein and hepatic vein or vena cava inferior.3, 4 Small shunts may close themselves before the age of 2 years.(5) With the increase in use of imaging methods, diagnosing PSS has become easier, with an increase in the number of cases reported.(6) Neonatal cholestatis is a frequent complication of PSS.(1) We present a case presenting with neonatal cholestasis diagnosed with congenital intrahepatic PSS.
- Determination of Porto-Azygos Shunt Anatomy in Dogs by Computed Tomography Angiography. [Journal Article]
- VSVet Surg 2016; 45(8):1005-1012
- CONCLUSIONS: CT angiography was well suited to provide anatomic details of porto-azygos shunts and comprehensively documented that all porto-azygos shunts had a thoracic terminus, after crossing the diaphragm through the esophageal hiatus. Different shunt types existed with minor variations.
- Acquired left ventricle-to-right atrium shunt: clinical implications and diagnostic dilemmas. [Review]
- WKWien Klin Wochenschr 2015; 127(21-22):884-92
- CONCLUSIONS: A high jet detected in the right atrium with uncertain origin and course has to appeal to additional diagnostic techniques including transesophageal echocardiography, cardiac catheterization, or cardiac magnetic resonance imaging for differential diagnoses. Small restrictive shunts are preferred with conservative treatments, high-risk patients are candidates of interventional therapy, and the patients with unstable hemodynamics warrant an open heart surgery. Careful operative maneuver, good control of intracardiac infection, preservation of heart function, etc., are mandatory for the prevention of the development of an acquired LV-RA shunt.
- Gerbode defect: Another nail for the 3D transesophagel echo hammer? [Review]
- IJInt J Cardiovasc Imaging 2015; 31(4):753-64
- Acquired type of LV to RA shunt (Gerbode defect) is rare form of intracardiac shunt which is due to complications of invasive cardiac procedures, endocarditis, trauma or myocardial infarction. Increa...
Acquired type of LV to RA shunt (Gerbode defect) is rare form of intracardiac shunt which is due to complications of invasive cardiac procedures, endocarditis, trauma or myocardial infarction. Increasing invasive and recurrent cardiovascular procedures have led to more acquired cases of what used to be a predominant congenital heart defect. Advanced cardiac imaging techniques and awareness of this rare pathology may account for the increased number of case reports in the last two decades Advanced cardiac imaging tools such as cardiac CT, MRI and Real-time 3D echocardiography provide definitive diagnosis and anatomic characterization of the shunt. Real-time 3D echocardiography is an imaging technique with arguably the most advantages. It is not only a diagnostic tool; it has also become an integral part of percutaneous and surgical treatment. Although surgical repair is the usual treatment for this shunt, percutaneous catheter-based closure has seen significant success as a less invasive treatment in selected patients in the last decade. In summary, a beneficial side effect of the increasing frequency of acquired Gerbode defect has been the corresponding development of newer diagnostic tools and less invasive treatments. This article presents etiologic, diagnostic and treatment changes of acquired LV-RA shunts over the last two decades.
- Cardiac magnetic resonance 'virtual catheterization' for the quantification of valvular regurgitations and cardiac shunt. [Case Reports]
- JCJ Cardiovasc Med (Hagerstown) 2015; 16(10):663-70
- Cardiac magnetic resonance (CMR) is considered the gold-standard noninvasive technique for the quantification of ventricular volumes by cine-imaging and of vascular flows by velocity-encoded phase co...
Cardiac magnetic resonance (CMR) is considered the gold-standard noninvasive technique for the quantification of ventricular volumes by cine-imaging and of vascular flows by velocity-encoded phase contrast (VENC). In routine CMR scans, it is common to found clinical conditions, as valve regurgitations and cardiac shunts, producing a volume overload and significant mismatch between the right and left ventricular stroke volumes (RSV and LSV). In the presence of a valve regurgitation, the volume overload involves the respective ventricular chamber, whereas in cardiac shunts, the location of the volume overload depends on the site of the anatomic defect. Moreover, when a cardiac shunt is present, pulmonary and systemic cardiac outputs are different (Qp/Qs < 1 or Qp/Qs > 1), whereas in the presence of valve regurgitation, Qp/Qs = 1. Therefore, by combining the cine-imaging with the VENC technique, it is possible to investigate the cardiac physiology underlying different pathological conditions producing volume overload, and to quantify this overload (the regurgitant volume and/or shunt volume). In this report, we discussed the technical, theoretical and methodological aspects of this sort of 'virtual catheterization' by CMR, providing a simple algorithm to make the correct diagnosis.
- Building foundations for transcatheter intervascular anastomoses: 3D anatomy of the great vessels in large experimental animals. [Journal Article]
- ICInteract Cardiovasc Thorac Surg 2014 Jul 3
- CONCLUSIONS: There are considerable differences in vascular anatomy between large experimental animals and humans. Given the need to elaborate new transcatheter techniques for intervascular anastomoses in suitable animal models before application to human, it is crucial to take these anatomical differences into account during testing and optimization of the proposed procedures.
- Imaging of patent foramen ovale with 64-section multidetector CT. [Journal Article]
- RRadiology 2008; 249(2):483-92
- CONCLUSIONS: Multidetector CT provides detailed anatomic information about size, morphologic features, and shunt grade of the PFO. Shorter tunnel length and septal aneurysms are frequently associated with left-to-right shunts in patients with PFO.
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- Epidemiologic factors associated with the anatomic location of intrahepatic portosystemic shunts in dogs. [Journal Article]
- VSVet Surg 2007; 36(1):31-6
- CONCLUSIONS: Although country of origin, breed, and sex had significant associations with anatomic location of IHPSS, signalment does not appear to be a strong predictor of shunt location when used alone.For the common breeds in this report, signalment is only occasionally helpful in predicting likelihood of anatomic division in IHPSS. Australian cattle dogs and male dogs have a statistical association with right (versus left) divisional IHPSS. If advanced imaging techniques are not available, veterinary surgeons should be prepared to locate and address any anatomic configuration of IHPSS in a dog.