Experimental Fetal Cardiopulmonary Bypass in the Fetal Lamb Model.
- Author:
Jeong Ryul LEE
1
;
Hong Gook LIM
;
Won Gon KIM
;
Jong Sung KIM
;
Jung Youn CHUI
;
Yong Jin KIM
Author Information
1. Department of Thoracic and Cardiovascular Surgery, Seoul National University Children's Hospital, Seoul National University College of Medicine, Seoul National University Medical Research Center, Heart Research Institute.
- Publication Type:Original Article
- Keywords:
Fetus;
Cardiopulmonary bypass;
Model, experimental
- MeSH:
Anesthesia, General;
Anesthesia, Spinal;
Anesthetics;
Arterial Pressure;
Atrial Pressure;
Cardiopulmonary Bypass*;
Catheters;
Constriction;
Extracorporeal Circulation;
Fetus;
Heart;
Heart Rate;
Hemodynamics;
Ketamine;
Models, Theoretical;
Oxygen;
Oxygenators;
Placenta;
Pregnancy;
Prostaglandin Antagonists;
Umbilical Cord;
Weights and Measures
- From:The Korean Journal of Thoracic and Cardiovascular Surgery
1999;32(6):495-503
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
BACKGROUND: We tested the technical feasibility of fetal cardiac bypass and collected baseline data on the fetal hemodynamics and placental functions related to the cardiopulmonary bypass in the fetal lamb model. MATERIAL AND METHOD: Eleven fetuses at 120 to 150 days of gestation were subjected to bypass via trans-sternal approach with a 12 G pulmonary arterial cannula and 14 to 18 F venous cannula for 30 minutes. All ewes received general anesthesia with ketamine. In all the fetuses, no anesthetic agents were used except muscle relaxant. Eight served as a group in which placenta was excluded from the extracorporeal circulation by clamping the umbilical cord during the bypass(the oxygenator group) and in the remaining three, the placenta worked as the only source of oxygen supply(the placenta group). Observations were made every 10 minute during a 30-minute bypass and 30-minute post bypass period. No prostaglandin inhibitors were used both in ewes and in fetuses. RESULT: Weights of the fetuses ranged from 1.9 to 5.2 kg. In the oxygenator group, means of arterial pressure, PaO2, atrial pressure, heart rate, and bypass flow rate ranged 69.8 to 82.6 mmHg, 201.7 to 220.9 mmHg, 4.1 to 4.3 mmHg, 169 to 182/min, and 140.3 to 164.0 ml/kg/min, respectively during bypass, but rapid deterioration of the fetal cardiac functions and the placental gas exchange was observed after the cessation of bypass. In the placenta group, means of arterial pressure decreased from 44.7 to 14.4 mmHg and means of PaCO2 increased from 61.9 to 129.6 mmHg during bypass. Flow rate was suboptimal(74.3 to 97.0 ml/kg/min) during bypass. All hearts fibrillated immediately after the discontinuation of bypass. CONCLUSION: In this study, the technical feasibility of fetal cardiopulmonary bypass was confirmed in the fetal lamb model. However, further studies with modifications of the bypass including an addition of prostaglandin inhibitor, an application of the total spinal anesthesia on the fetus, a creation of more concise bypass circuit, and a use of active pump are mandatory to improve the outcome.
