Fetal Circulation & Fetal Surgery

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Fetal Circulation & Fetal SurgerySeoul National University Hospital Department of Thoracic & Cardiovascular Surgery

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Fetal Cardiac SurgerySeoul National University Hospital

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Fetal Cardiac Surgery

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Operative Technique (I)

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Operative Technique (II)

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Operative Technique (III)

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Fetal Surgery (Diaphragmatic Hernia)

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Vascular Pressures in Normal Fetal Lambs

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Normal Fetal Circulation : Saturation

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Percentages of Fetal Cardiac Output

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Normal Fetal CirculationPercent flowSaturation

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Langendorff Isolated Perfusion Apparatus

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Circuitry of Isolated Heart Preparation

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Effects of Surgical Stress and Anesthesia

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Circuits for Fetal Extracorporeal Circulatory Support

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Isolated Placental Preparation

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Extracorporeal Circuit of Isolated Placental Preparation

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Maternal Positioning & Monitoring in Fetal Cardiac Surgery

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Management of the Fetus With a Correctable Congenital Defect

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Regulation of Fetal Circulation 1. Local regulation 2. Baroreflex regulation 3. Chemoreflex regulation 4. Autonomic nervous system 5. Hormonal regulation . Catecholamines . Renin-Angiotensin system . Vasopressin . Arachidonic acid metabolites

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Isolation of the Placenta during Bypass 1. Placenta remained in bypass circuit ⊙ Advantage . Eliminating an extracorporeal oxygenator . Placenta acts as the gas exchange unit ⊙ Disadvantage . Continuous stimulation of the production of vasoactive substances . Large flow rate 2. Removal of placenta in bypass circuit ⊙ Advantage . Decreased stimulation of vasoactive substances . Reduced required flow rate ⊙ Disadvantage . Oxygenator needed . Effects of arresting placental flow

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Fetal Stress Response The ideal fetal anesthesia should be easy to administer, totally block the stress response, not cause fetal myocardial depression, and not disrupt the balance of resistances in various peripheral vascular beds. ⊙ Opiates ⊙ Ketamine ⊙ Halothane ⊙ Total spinal anesthesia (Tetracaine) ** Elevation of various stress hormone, including endogenous catecholamine, release of prostaglandins during fetal surgical exposure and bypass.

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Placental Response to Fetal Cardiopulmonary Bypass Placental dysfunction was found to be result of elevated placental vascular resistance ⊙ Pulsatile flow ⊙ Nitroprusside ⊙ Indomethacin : block the arachidonic acid cascade at the cyclooxygenase step ⊙ Corticosteroid : block at the arachidonic acid cascade at the phospholipase step ** Vasoactive cyclooxygenase product (PGE2, Thromboxane) Acute death following fetal bypass is caused by reduced placental blood flow, hypercarbia, hypoxia, lactic acidosis and terminal ventricular fibrillation.

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Transvaginal Fetal Echocardiography ⊙ Standard cardiac projection at gestational week 12, and many were imaged by week 11. ⊙ The four-chamber view in 90% of fetuses at 12 weeks?gestation and 100% at 13 weeks. ⊙ Aortic, pulmonary, ductus arteriosus and aortic arch at 12 weeks. ⊙ Mitral & tricuspid valves were resolved in 60% of fetuses by 11 weeks?gestation.

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Fetal Intervention for Congenital Heart Disease 1. The ability to diagnose specific lesions in utero 2. A clear advantage to correcting the lesion before birth 3. A technical skills and knowledge to correct safely

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Open Fetal Surgical Correction in Humans 1. Diaphragmatic hernia 2. Obstructive hydronephrosis 3. Sacrococcygeal teratomas 4. Congenital cystic adenomatoid malformation

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Last Updated: 8th March 2018