The bidirectional cavopulmonary shunt may be useful as an intermediate procedure before Fontan operation in high-risk patients, because it provides adequate relief of canosis and relief of ventricular volume overload. But there are no established
theory
about the effects of bidirectional cavopulmonary shunt on pulmonary arterial development. The purpose of this article is a study of changes of pulmonary artery size after bidirectional cavopulmonary shunt.
Cardiac catheterization and angiography procedures were done on 19 patients who underwent bidirectional cavopulmonary shunt from February 1992 to July 1994, their results were reviewed. Preoperative cardiac catheterization and angiograpjy
procedures
were performed at a mean interval of 3.8±4.8(±SEM) months before surgery and following catheterization at a mean postoperative interval of 19.6±4.8 months. Pulmonary arterial size measurement were standardized for body surface area(Pulmonary
artery
index), and for diameter of descending thoracic aorta(McGoon ratio). Patient's age, body surface area, pulmonary angioplasty, preoperative McGoon ratio and follow-up intervals were considered as variables.
Before bidirectional cavopulmonary shunt, patient's mean age, body surface area, arterial O2 saturation, diameter of right pulmonary artery, diameter of left pulmonary artery, pulmonary artery index, McGoon ratio were 13.7±15.6 months,
0.40±0.12㎡,
71.4±12.4%, 7.1±1.7mm, 6.2±1.7, 191.8±82.7㎟/㎡, 1.73±0.49, respectiyely. After bidirectional cavopulmonary shunt, the values were changed to 39.9±16.2months, 0.58±0.07 ㎡, 83.0±3.8%, 9.0±1.5mm, 7.7±2.0, 197.3±57.1 ㎟/㎡, 1.76±0.32,
respectively.
With patients' development(age, body surface area), diameters of pulmonary arteries were increased, but pulmonary artery indices and McGoon ratios were not changed. And there were no effects of age, body surface area, amount of increased O2
saturation,
pulmonary angiography and follow-up duration on the increment of pulmonary artery size. But when the McGoon ration was as low as 1.2, there were significant increase in postoperative pulmonary artery sizes. There was a significant correlation
between
preoperative pulmonary artery index(PAI) and McGoon ratio(MGR);
PAI=MGR×118.0-12.4
In conclusion, bidirectional cavopulmonary shunt provides adequate increment of arterial O2 saturation and does not increase the pulmonary artery size. Further investigation is mandatory to evaluate the effect of pulsatile bidirectional
cavopulmonary
shunt on pulmonary artery growth.
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