Hemodynamics of the Fontan Connection: An In-Vitro Study

1995 ◽  
Vol 117 (4) ◽  
pp. 423-428 ◽  
Author(s):  
Young H. Kim ◽  
P. G. Walker ◽  
A. A. Fontaine ◽  
S. Panchal ◽  
A. E. Ensley ◽  
...  

The Fontan operation is one in which the right heart is bypassed leaving the left ventricle to drive the blood through both the capillaries and the lungs, making it important to design an operation which is hemodynamically efficient. The object here was to relate the pressure in Fontan connections to its geometry with the aim of increasing the hemodynamically efficiency. From CT or magnetic resonance images, glass models were made of realistic atrio-pulmonary (AP) and cavo-pulmonary (CP) connections in which the right atrium and/or ventricle are bypassed. The glass models were connected to a steady flow loop and flow visualization, pressure and 3 component LDA measurements made. In the AP model the large atrium and curvature of the conduit created swirling patterns, the magnitude of which was similar to the axial velocity. This led to an inefficient flow and a subsequent large pressure loss (780 Pa). In contrast, the CP connection with a small intra-atrial chamber had reduced swirling and a significantly smaller pressure loss (400 Pa at 8 l.min) and was therefore a more efficient connection. There were, however, still pressure losses and it was found that these occurred where there was a large bending of the flow, such as from the superior vena cava to the MPA and from the MPA to the right pulmonary artery.

2017 ◽  
Vol 26 (9) ◽  
pp. 701-703
Author(s):  
Hidetsugu Asai ◽  
Tsuyoshi Tachibana ◽  
Yasushige Shingu ◽  
Hiroki Kato ◽  
Satoru Wakasa ◽  
...  

The left superior vena cava became occluded in an infant with hypoplastic left heart syndrome. After a bidirectional Glenn procedure, he presented with severe oxygen desaturation and right ventricular dysfunction; the left superior vena cava drained into the inferior vena cava through collateral veins. As salvage therapy, we created a modified total cavopulmonary shunt using only autologous tissue in which the right hepatic vein and inferior vena cava drained into the pulmonary artery via a lateral tunnel in the right atrium. Immediately after surgery, his oxygen saturation increased and right ventricular function improved.


2021 ◽  
Vol 36 (5) ◽  
pp. 267-278
Author(s):  
Tatiana K. Dobroserdova ◽  
Yuri V. Vassilevski ◽  
Sergey S. Simakov ◽  
Timur M. Gamilov ◽  
Andrey A. Svobodov ◽  
...  

Abstract Palliation of congenital single ventricle heart defects suggests multi-stage surgical interventions that divert blood flow from the inferior and superior vena cava directly to the right and left pulmonary arteries, skipping the right ventricle. Such system with cavopulmonary anastomoses and single left ventricle is called Fontan circulation, and the region of reconnection is called the total cavopulmonary connection (TCPC). Computational blood flow models allow clinicians to predict the results of the Fontan operation, to choose an optimal configuration of TCPC and thus to reduce negative postoperative consequences. We propose a two-scale (1D3D) haemodynamic model of systemic circulation for a patient who has underwent Fontan surgical operation. We use CT and 4D flow MRI data to personalize the model. The model is tuned to patient’s data and is able to represent measured time-averaged flow rates at the inlets and outlets of TCPC, as well as pressure in TCPC for the patient in horizontal position.We demonstrate that changing to quiescent standing position leads to other patterns of blood flow in regional (TCPC) and global haemodynamics. This confirms clinical data on exercise intolerance of Fontan patients.


2004 ◽  
Vol 9 (3) ◽  
pp. 150-154
Author(s):  
Ari I. Salis ◽  
Anthony Eclavea ◽  
Matthew S. Johnson ◽  
Nilesh H. Patel ◽  
Debie G. Wong ◽  
...  

ABSTRACT Purpose Currently available 4 French and 5 French PICCs were investigated to evaluate their possible application for contrast injection using power injectors. The study was performed using an in-vitro model to demonstrate the feasibility of using PICCs for contrast enhanced studies. Materials and Methods An evaluation of 24 catheter versions consisting of 4 French single lumen and 5 French dual lumen PICCs from 13 different manufacturers was conducted. Six of the catheter types were silicone and 18 catheter types were polyurethane. Ten catheters of each type were evaluated with five at full length and five trimmed to 40cm. Using a silicone-based simulated superior vena cava model, the catheters were infused with 50cc of intravenous contrast at each flow rate increment. Catheters were tested at increasing flow rates from 0.5cc/second to 5cc/second in 0.5cc/second increments using a Percupump CT injector. Catheters that failed to rupture were then infused at 1 cc/second increments at flow rates from 5cc/second to 17cc/second using a MedRad Mark VTM power injector. Tolerated and bursting pressures were recorded. Results Polyurethane catheters ruptured at flow rates between 4–15.4cc/second, with one catheter not rupturing at the maximum flow rate (l7cc/second). Silicone catheters ruptured at flow rates between 0.5–3.5cc/second. Average rupture locations by type and length were at the extension leg/hub connection area on 5 of the PICCs, on the extension legs on 21 of the PICCs, on the catheter/hub connection on 4 PICCs, and on the proximal catheter on 16 of the PICCs. Conclusion The low burst rates at which all silicone catheters ruptured suggest those catheters are not able to withstand typical flow rates used for CTA. Conversely, although a wide range of discrepancy is found in the polyurethane catheter burst pressures, many polyurethane catheters can tolerate relatively high flow rates without rupture. This suggests that they may be safely used for CTA with appropriate precautions and protocols in place.


2021 ◽  
pp. 152660282198933
Author(s):  
Pablo V. Uceda ◽  
Julio Peralta Rodriguez ◽  
Hernán Vela ◽  
Adelina Lozano Miranda ◽  
Luis Vega Salvatierra ◽  
...  

The health care system in Peru treats 15,000 dialysis patients annually. Approximately 45% of patients receive therapy using catheters. The incidence of catheter-induced superior vena cava (SVC) occlusion is increasing along with its associated significant morbidity and vascular access dysfunction. One of the unusual manifestations of this complication is bleeding “downhill” esophageal varices caused by reversal of blood flow through esophageal veins around the obstruction to the right atrium. Herein is presented the case of an 18-year-old woman on hemodialysis complicated by SVC occlusion and bleeding esophageal varices who underwent successful endovascular recanalization of the SVC. Bleeding from “downhill” esophageal varices should be considered in the differential diagnosis of dialysis patients exposed to central venous catheters. Aggressive endovascular treatment of SVC occlusion is recommended to preserve upper extremity access function and prevent bleeding from this complication.


Author(s):  
Reina Tonegawa-Kuji ◽  
Kenichiro Yamagata ◽  
Kengo Kusano

Abstract Background  Cough-induced atrial tachycardia (AT) is extremely rare and its electrical origin remains largely unknown. Atrial tachycardias triggered by pharyngeal stimulation, such as swallowing or speech, appears to be more common and the majority of them originate from the superior vena cava or right superior pulmonary vein (PV). Only one case of swallow-triggered AT with right inferior pulmonary vein (RIPV) origin has been reported to date. Case summary  We present a case of a 41-year-old man with recurring episodes of AT in the daytime. He underwent electrophysiology study without sedation. Atrial tachycardia was not observed when the patient entered the examination room and could not be induced with conventional induction procedures. By having the patient cough periodically on purpose, transient AT with P-wave morphology similar to the clinical AT was consistently induced. Activation mapping of the AT revealed a centrifugal pattern with the earliest activity localized inside the RIPV. After successful radiofrequency isolation of the right PV, AT was no longer inducible. Discussion  In the rare case of cough-induced AT originating from the RIPV, the proximity of the inferior right ganglionated plexi (GP) suggests the role of GP in triggering tachycardia. This is the first report that demonstrates voluntary cough was used to induce AT. In such cases that induction of AT is difficult using conventional methods, having the patient cough may be an effective induction method that is easy to attempt.


2021 ◽  
pp. 1-3
Author(s):  
Rajashekar Rangappa Mudaraddi ◽  
Hany Fawzi Greiss ◽  
Navin Kumar Manickam

Central venous cannulation is the most common procedure performed in perioperative setting and intensive care unit. Many case reports reported unusual positioning of central line catheters. Here, we would like to report a case of central line path in persistent left superior vena cava, a rare entity with a course similar to the right internal jugular central line. Preoperative computed tomography chest showed duplex superior vena cava which was not reported.


2020 ◽  
Vol 21 (Supplement_1) ◽  
Author(s):  
I Marco Clement ◽  
R Eiros ◽  
R Dalmau ◽  
T Lopez ◽  
G Guzman ◽  
...  

Abstract Introduction The diagnosis of sinus venosus atrial septal defect (SVASD) is complex and requires special imaging. Surgery is the conventional treatment; however, transcatheter repair may become an attractive option. Case report A 60 year-old woman was admitted to the cardiology department with several episodes of paroxysmal atrial flutter, atrial fibrillation and atrioventricular nodal reentrant tachycardia. She reported a 10-year history of occasional palpitations which had not been studied. A transthoracic echocardiography revealed severe right ventricle dilatation and moderate dysfunction. Right volume overload appeared to be secondary to a superior SVASD with partial anomalous pulmonary venous drainage. A transesophageal echocardiography confirmed the diagnosis revealing a large SVASD of 16x12 mm (Figure A) with left-right shunt (Qp/Qs 2,2) and two right pulmonary veins draining into the right superior vena cava. Additionally, it demonstrated coronary sinus dilatation secondary to persistent left superior vena cava. CMR and cardiac CT showed right superior and middle pulmonary veins draining into the right superior vena cava 18 mm above the septal defect (Figures B and C). After discussion in clinical session, a percutaneous approach was planned to correct the septal defect and anomalous pulmonary drainage. For this purpose, anatomical data obtained from CMR and CT was needed to plan the procedure. During the intervention two stents graft were deployed in the right superior vena cava. The distal stent was flared at the septal defect level so as to occlude it while redirecting the anomalous pulmonary venous flow to the left atrium (Figure D). Control CT confirmed the complete occlusion of the SVASD without residual communication from pulmonary veins to the right superior vena cava or the right atrium (Figure E). Anomalous right superior and middle pulmonary veins drained into the left atrium below the stents. Transthoracic echocardiographies showed progressive reduction of right atrium and ventricle dilatation. The patient also underwent successful ablation of atrial flutter and intranodal tachycardia. She is currently asymptomatic, without dyspnea or arrhythmic recurrences. Conclusions In this case, multimodality imaging played a key role in every stage of the clinical process. First, it provided the diagnosis and enabled an accurate understanding of the patient’s anatomy, particularly of the anomalous pulmonary venous connections. Secondly, it allowed a transcatheter approach by supplying essential information to guide the procedure. Finally, it assessed the effectiveness of the intervention and the improvement in cardiac hemodynamics during follow-up. Abstract P649 Figure.


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