The experimental study of neonatal myocardial protection for left ventricular hypertrophied heart using fetal lambs and kids.

1995 Fiscal Year Final Research Report Summary

• Project/Area Number: 06671324
• Research Category: Grant-in-Aid for General Scientific Research (C)
• Allocation Type: Single-year Grants
• Research Field: Thoracic surgery
• Research Institution: TOHOKU UNIVERSITY
• Principal Investigator: SADAHIRO Mitsuaki Tohoku University, School of Medicine, Assistant, 医学部附属病院, 助手 (80250778)
• Co-Investigator(Kenkyū-buntansha): HATA Masaki Tohoku University, School of Medicine, Doctor, 医学部附属病院, 医員
• Project Period (FY): 1994 – 1995
• Keywords: PREGNANT EWE / FETUS / INTRAUTERINE OPERATION / LEFT VENTRICULAR HYPERTROPHY / NEONATAL MYOCARDIAL PROTECTION

Research Abstract

The purpose of the research is to establish the neonatal hypertrophied heart model by intrauterine operation of lambs in order to study the neonatal myocardial protection technique Fetal preparation surgery was performed on 5ewes The pregnant sheep were operated at the gestation age form 120 to 140 days. Anesthesia was inducted with sodium thiopental and maintained by 0.5-1.5% of halothane mixed with 100% oxygen. The animals were intubated and mechanically ventilated. After hysterectomy, the chest of fetus was exteriorized and right sided 4th intercostal space was opened. Ascending aorta was divided with sharp and blunt dissection, then taped and snared to created left ventricle pressure overloading. The chest was closed and the fetus was returned to the uterus. After uterus and abdominal wall of sheep was approximated in layr and subsequent gestation was allowed to processed.
One of five fetus died during surgery because of bleeding around pulmonary artery just beside ascending aorta. A mother sheep had an abortion with her fetus died. The other three fetus were also determined to die between one and 7 days after surgery in the uterine or at birth. Reasons described below were considered to be related to this results.
1. Season for intrauterine surgery was limited in winter, December to March, when pregnant sheep was available for the study.
2. More fine and gentle surgical procedure was necessary to perform fetus operation. Surgical stress on pregnant sheep had to be reduced to allowed gestation to proceed.
3. The fetus might not toleratethe surgery due to relative complexity of the surgery.
Hemodynamic performance after myocardial protection of hypertrophied newborn lamb heart could not be assessed because any long term survivors were not obtained in this study. However, we had obtained many knowledge about intrauterine operation, and we are sure that our experiences in the study would be helpful for further fetus surgery.