Pediatric cardiac surgery without homologous blood transfusion, using a miniaturized bypass system in infants with lower body weight.
OBJECTIVE
We have established a low-priming volume cardiopulmonary bypass system for pediatric heart surgery to avoid homologous blood transfusion. The priming volume of our system is down to 140 mL for patients weighing less than 7 kg. We can prime the bypass circuits without blood products for patients weighing more than 4 kg.


METHODS
Seventy consecutive patients weighing 4 to 7 kg underwent heart surgery with a bloodless prime from October 2003 to September 2006. The type of procedures (Risk Adjustment in Congenital Heart Surgery category) included the following: category 1: atrial septal defect (n = 3); category 2: ventricular septal defect, tetralogy of Fallot, bidirectional Glenn shunt, and others (n = 55); category 3: atrioventricular septal defect, double-outlet right ventricle, and others (n = 8); category 4: Rastelli procedure for transposition of the great arteries (n = 3); and category 6, Damus-Kaye-Stansel procedure (n = 1). Transfusion criteria were hematocrit less than 20%, mixed venous oxygen saturation less than 70%, regional cerebral oxygenation less than 50%, and plasma lactate level greater than 4.0 mmol/L during bypass.


RESULTS
The mean age and body weight were 7.3 +/- 5.4 months and 5.4 +/- 0.8 kg, respectively. Forty-five patients (64%) underwent transfusion-free procedures. Preoperative hematocrit, age, body weight, complexity of procedure and cardiopulmonary bypass time were compared between patients with and without transfusion. Bypass time and Risk Adjustment in Congenital Heart Surgery risk category in patients with transfusion were significantly greater than those in patients without (P < .0001, and P < .05, respectively). Body weight in patients without transfusion was significantly greater than that in patients with (P < .01). In multiple regression analysis, the determinants of blood transfusion were the bypass time and body weight (odds ratio 1.026, 95% confidence interval 1.011-.040, P < .0001, and odds ratio 0.366, 95% confidence interval 0.171-0.785, P < .01).


CONCLUSIONS
It is possible to do complex transfusion-free procedures safely for patients weighing more than 4 kg by using the low-priming volume circuit. The limiting factors of bloodless heart surgery are not preoperative hematocrit and complexity of procedure but the cardiopulmonary bypass time and the patient's body weight.
Department of Thoracic and Cardiovascular Surgery, Kitasato University School of Medicine, Sagamihara, Japan. kagami111@aol.com
Kagami
K
Miyaji
Satoshi
S
Kohira
Takashi
T
Miyamoto
Kouki
K
Nakashima
Hajime
H
Sato
Kuniyoshi
K
Ohara
Hirokuni
H
Yoshimura
D001803:Blood Transfusion; D001835:Body Weight; D006348:Cardiac Surgical Procedures; D002315:Cardiopulmonary Bypass / Q000379:methods*; D005260:Female; D006330:Heart Defects, Congenital / Q000601:surgery*; D006801:Humans; D007223:Infant; D008297:Male; D008904:Miniaturization; D010100:Oxygen / Q000378:metabolism; D012044:Regression Analysis; D018570:Risk Assessment; D012307:Risk Factors; D018709:Statistics, Nonparametric
D010100:Oxygen