Mechanical Circulatory Support for the Failing Fontan: Conversion to Assisted Single Ventricle Circulation—Preliminary Observations

2018 ◽  
Vol 9 (1) ◽  
pp. 31-37 ◽  
Author(s):  
Syed M. Peer ◽  
Kristopher B. Deatrick ◽  
Thomas J. Johnson ◽  
Jonathan W. Haft ◽  
Francis D. Pagani ◽  
...  
Keyword(s):  
Blood Flow ◽  
Mechanical Circulatory Support ◽  
Single Ventricle ◽  
Main Pulmonary Artery ◽  
Fontan Circulation ◽  
Arterial Oxygen ◽  
Circulatory Support ◽  
Baseline Serum ◽  
Arterial Blood ◽  
Failing Fontan

Background: Mechanical circulatory support (MCS) of a failing Fontan circulation remains challenging. We hypothesized that MCS can be provided by converting the Fontan circulation into a mechanically assisted single ventricle parallel circulation (MASVC). Methods: A porcine model of functionally univentricular circulation was created under cardiopulmonary bypass (CPB) by performing an atrial septectomy, tricuspid valvectomy, and interrupting antegrade pulmonary blood flow. A centrifugal flow pump was placed with inflow from the common atrium. Eight millimeter Dacron grafts anastomosed to the ascending aorta and main pulmonary artery supplied systemic (Qs) and pulmonary (Qp) blood flow. Ultrasonic flow probes were used to measure Qs and Qp after weaning from CPB. The Qp/Qs ratio was regulated using an adjustable clamp. Hemodynamic and laboratory data were recorded. Results: All four animals were successfully weaned from CPB onto the MASVC for a duration of two hours. Mechanically assisted single ventricle parallel circulation achieved satisfactory hemodynamics. As anticipated, the arterial oxygen saturation and partial pressure of oxygen in arterial blood were lower in the MASVC compared to baseline biventricular circulation. At the conclusion of the study, there was a trend towards a decrease in the mixed venous saturation with increasing oxygen extraction compared to the baseline. Serum lactate levels increased after weaning from CPB and did not return to baseline after two hours of support. Conclusion: Mechanically assisted single ventricle parallel circulation can be established in a single ventricle animal model. This strategy could potentially provide MCS of a single ventricle circulation. Studies with longer duration of support are required to assess adequacy of support and long-term sustainability.

A modified LVAD technique to augment caval and pulmonary arterial blood flow in the “failing Fontan” circulation

2017 ◽  
Vol 32 (2) ◽  
pp. 126-132 ◽  
Author(s):  
Michael F. Swartz ◽  
Louis DiVincenti ◽  
Karen Smith ◽  
Robin Westcott ◽  
Kevin Belmont ◽  
...  
Keyword(s):  
Blood Flow ◽  
Fontan Circulation ◽  
Arterial Blood Flow ◽  
Arterial Blood ◽  
Pulmonary Arterial ◽  
Failing Fontan

Peripheral chemoreflex activation and cardiac function during hypoxemia in near term fetal sheep without placental compromise

2021 ◽  
Author(s):  
Juulia Lantto ◽  
Tiina Erkinaro ◽  
Mervi Haapsamo ◽  
Heikki Huhta ◽  
Leena Alanne ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Carotid Artery ◽  
Arterial Oxygen ◽  
Sheep Model ◽  
Fetal Sheep ◽  
Descending Aorta ◽  
Arterial Blood ◽  
Near Term ◽  
Peripheral Chemoreflex

A drop in arterial oxygen content activates fetal chemoreflex including an increase in sympathetic activity leading to peripheral vasoconstriction and redistribution of blood flow to protect the brain, myocardium, and adrenal glands. By using a chronically instrumented fetal sheep model with intact placental circulation at near-term gestation, we investigated the relationship between peripheral chemoreflex activation induced by hypoxemia and central hemodynamics. 17 Åland landrace sheep fetuses at 115-128/145 gestational days were instrumented. Carotid artery was catheterised in 10 fetuses and descending aorta in 7 fetuses. After a 4-day recovery, baseline measurements of fetal arterial blood pressures, blood gas values, and fetal cardiovascular hemodynamics by pulsed Doppler ultrasonography were obtained under isoflurane-anesthesia. Comparable data to baseline was collected 10 (acute hypoxemia) and 60 minutes (prolonged hypoxemia) after maternal hypo-oxygenation to saturation level of 70-80% was achieved. During prolonged hypoxemia, pH and base excess (BE) were lower, and lactate levels higher in the descending aorta than in the carotid artery. During hypoxemia mean arterial blood pressure (MAP) in the descending aorta increased, while in the carotid artery MAP decreased. In addition, right pulmonary artery pulsatility index values increased, and the diastolic component in the aortic isthmus blood flow velocity waveform became more retrograde. Both fetal ventricular cardiac outputs were maintained even during prolonged hypoxemia when significant fetal metabolic acidemia developed. Fetal chemoreflex activation induced by hypoxemia decreased the perfusion pressure in the cerebral circulation. Fetal weight-indexed LVCO or AoI Net Flow-ratio did not correlate with a drop in carotid artery blood pressure.

scholarly journals Bidirectional Ductal Shunting and Preductal to Postductal Oxygenation Gradient in Persistent Pulmonary Hypertension of the Newborn

Children ◽  
2020 ◽  
Vol 7 (9) ◽  
pp. 137
Author(s):  
Amy Lesneski ◽  
Morgan Hardie ◽  
William Ferrier ◽  
Satyan Lakshminrusimha ◽  
Payam Vali
Keyword(s):  
Blood Flow ◽  
Pulmonary Hypertension ◽  
Pulmonary Blood Flow ◽  
Ductus Arteriosus ◽  
Arterial Oxygen Tension ◽  
Persistent Pulmonary Hypertension ◽  
Arterial Oxygen ◽  
Meconium Aspiration ◽  
Arterial Blood Gas ◽  
Arterial Blood

Background: The aim was to evaluate the relationship between the direction of the patent ductus arteriosus (PDA) shunt and the pre- and postductal gradient for arterial blood gas (ABG) parameters in a lamb model of meconium aspiration syndrome (MAS) with persistent pulmonary hypertension of the newborn (PPHN). Methods: PPHN was induced by intermittent umbilical cord occlusion and the aspiration of meconium through the tracheal tube. After delivery, 13 lambs were ventilated and simultaneous 129 pairs of pre- and postductal ABG were drawn (right carotid and umbilical artery, respectively) while recording the PDA and the carotid and pulmonary blood flow. Results: Meconium aspiration resulted in hypoxemia. The bidirectional ductal shunt had a lower postductal partial arterial oxygen tension ([PaO2] with lower PaO2/FiO2 ratio—97 ± 36 vs. 130 ± 65 mmHg) and left pulmonary flow (81 ± 52 vs. 133 ± 82 mL/kg/min). However, 56% of the samples with a bidirectional shunt had a pre- and postductal saturation gradient of < 3%. Conclusions: The presence of a bidirectional ductal shunt is associated with hypoxemia and low pulmonary blood flow. The absence of a pre- and postductal saturation difference is frequently observed with bidirectional right-to-left shunting through the PDA, and does not exclude a diagnosis of PPHN in this model.

Effects of l-Epinephrine and l-Norepinephrine on the Splanchnic Bed of Intact Dogs

1957 ◽  
Vol 189 (3) ◽  
pp. 576-579 ◽  
Author(s):  
E. Allbaugh Farrand ◽  
R. Larsen ◽  
Steven M. Horvath
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Splanchnic Blood Flow ◽  
Arterial Oxygen ◽  
Arterial Oxygen Content ◽  
Metabolic Functions ◽  
Arterial Blood ◽  
Anesthetized Dogs ◽  
Change In Mean ◽  
Infusion Period

The changes in splanchnic blood flow and related metabolic functions which occurred as the result of the infusion of 0.1 µg/kg/min. of l-epinephrine and l-norepinephrine for 10 minutes were measured in anesthetized dogs. l-Epinephrine elicited a marked increase in estimated splanchnic blood flow and no change in mean arterial pressure. While a significantly increased mean arterial blood pressure was observed following the administration of l-norepinephrine, no change in estimated splanchnic blood flow occurred. Arterial oxygen content was increased significantly with both drugs. Utilization of oxygen by the splanchnic bed was not changed during the infusion of either drug but was increased during the postepinephrine infusion period.

A Viable Therapeutic Option: Mechanical Circulatory Support of the Failing Fontan Physiology

2013 ◽  
Vol 34 (6) ◽  
pp. 1357-1365 ◽  
Author(s):  
Amy L. Throckmorton ◽  
Sergio Lopez-Isaza ◽  
Emily A. Downs ◽  
Steven G. Chopski ◽  
James J. Gangemi ◽  
...  
Keyword(s):  
Mechanical Circulatory Support ◽  
Therapeutic Option ◽  
Circulatory Support ◽  
Fontan Physiology ◽  
Failing Fontan

scholarly journals Mechanical Circulatory Support for the Fontan Circulation

2016 ◽  
Vol 35 (4) ◽  
pp. S131 ◽  
Author(s):  
L.C. Reardon ◽  
H. Laks ◽  
R. Biniwale ◽  
A. Hageman ◽  
R. Bolanos ◽  
...  
Keyword(s):  
Mechanical Circulatory Support ◽  
Fontan Circulation ◽  
Circulatory Support

scholarly journals Temporary and Durable Mechanical Circulatory Support for Single Ventricular Failure in an Adult

2016 ◽  
Author(s):  
Joshua L. Hermsen ◽  
Jason W. Smith ◽  
Jay D. Pal ◽  
Agustin Rubio ◽  
S. Carolina Masri ◽  
...  
Keyword(s):  
Mechanical Circulatory Support ◽  
Fontan Circulation ◽  
Circulatory Support ◽  
Ventricular Failure ◽  
Fontan Patient ◽  
Anatomy And Physiology ◽  
Support Devices

Patients palliated with Fontan circulation who require mechanical circulatory support pose anatomic and physiologic challenges. We treated an acutely failed Fontan patient with sequential temporary and durable support devices. Aspects of treatment with each device required modification based on the patient’s anatomy and physiology.

Effects of protoveratrine on coronary blood flow of the renal hypertensive dog

1963 ◽  
Vol 204 (5) ◽  
pp. 895-898 ◽  
Author(s):  
James W. West ◽  
Elwood L. Foltz
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Oxygen Saturation ◽  
Coronary Blood Flow ◽  
Arterial Oxygen Saturation ◽  
Renal Hypertension ◽  
Peripheral Resistance ◽  
Arterial Oxygen ◽  
Arterial Blood ◽  
Venous Oxygen Saturation

In renal hypertension, protoveratrine decreased coronary blood flow, cardiac oxygen consumption, arterial and venous oxygen saturation, coronary arteriovenous oxygen difference, mean arterial blood pressure, cardiac output, cardiac work, cardiac efficiency, cardiac rate, total peripheral resistance, coronary resistance, respiratory rate, and minute volume. The decrease was significant in all functions except coronary blood flow, coronary venous oxygen saturation, and cardiac output. The results of these experiments indicate that in the renal hypertensive animal, a therapeutically beneficial effect was derived from protoveratrine on the circulation by its ability to decrease the work of the heart (lowering the elevated mean arterial pressure) and the coronary vascular resistance while maintaining coronary blood flow and cardiac output within normal levels. The less advantageous effect of protoveratrine on circulation resulted from its respiratory inhibiting effect which reduced the arterial blood oxygen saturation. Although a small decline in coronary venous oxygen saturation was noted, the coronary flow and oxygen delivery in face of the reduced arterial oxygen saturation was apparently adequate to maintain a normal cardiac activity.

scholarly journals Feasibility of phase-contrast cine magnetic resonance imaging for measuring blood flow in the sheep fetus

2019 ◽  
Vol 317 (6) ◽  
pp. R780-R792 ◽  
Author(s):  
An Qi Duan ◽  
Jack R. T. Darby ◽  
Jia Yin Soo ◽  
Mitchell C. Lock ◽  
Meng Yuan Zhu ◽  
...  
Keyword(s):  
Blood Flow ◽  
Phase Contrast ◽  
Interobserver Agreement ◽  
Main Pulmonary Artery ◽  
Ductus Venosus ◽  
Cine Mri ◽  
Flow Measurements ◽  
Fetal Sheep ◽  
Fetal Circulation ◽  
Arterial Blood

Phase-contrast cine MRI (PC-MRI) is the gold-standard noninvasive technique for measuring vessel blood flow and has previously been applied in the human fetal circulation. We aimed to assess the feasibility of using PC-MRI to define the distribution of the fetal circulation in sheep. Fetuses were catheterized at 119–120 days of gestation (term, 150 days) and underwent MRI at ∼123 days of gestation under isoflurane anesthesia, ventilated at a [Formula: see text] of 1.0. PC-MRI was performed using a fetal arterial blood pressure catheter signal for cardiac triggering. Blood flows were measured in the major fetal vessels, including the main pulmonary artery, ascending and descending aorta, superior vena cava, ductus arteriosus, left and right pulmonary arteries, umbilical vein, ductus venosus, and common carotid artery and were indexed to estimated fetal weight. The combined ventricular output, pulmonary blood flow, and flow across the foramen ovale were calculated from vessel flows. Intraobserver and interobserver agreement and reproducibility was assessed. Blood flow measurements were successfully obtained in 61 out of 74 vessels (82.4%) interrogated in 9 fetuses. There was good intraobserver [ R = 0.998, P < 0.0001; intraclass correlation (ICC) = 0.997] and interobserver agreement ( R = 0.996, P < 0.0001; ICC = 0.996). Repeated MRI measurements showed good reproducibility ( R = 0.989, P = 0.0002; ICC = 0.990). We conclude that PC-MRI using fetal catheters for gating triggers is feasible in the major vessels of late gestation fetal sheep. This approach may provide a useful new tool for assessing the circulatory characteristics of fetal sheep models of human disease, including fetal growth restriction and congenital heart disease.

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