The functional intraoperative pulmonary blood flow study is a more sensitive predictor than preoperative anatomy for right ventricular pressure and physiologic tolerance of ventricular septal defect closure after complete unifocalization in patients with pulmonary atresia, ventricular septal defect, and major aortopulmonary collaterals.
BACKGROUND
The objective was to determine if intraoperative pulmonary artery (PA) flow studies after complete unifocalization correlate with postrepair hemodynamics for pulmonary atresia (PA), ventricular septal defects (VSD), and major aortopulmonary collaterals.


RESULTS
Twenty patients (median age, 8 months; weight, 7.9 kg) underwent unifocalization between 2003 and 2008. A functional PA flow study was achieved by cannulating the unifocalized central PA before intracardiac repair and increasing flow incrementally to 2.5 L/min per m(2). Mean PA pressure (mPAP) was measured. The intent was to close the VSD for a mPAP of <30 mm Hg. Right ventricular systolic pressure (RVSP) and systemic systolic pressure were recorded. Total incorporated pulmonary segments, pulmonary segment artery ratio (ratio of incorporated segments to 18), and total neopulmonary artery index (the sum of major aortopulmonary collaterals and native PA index) were calculated. The VSD was successfully closed in 18 patients (90%). One attempted closure required an intraoperative fenestration. The study mPAP correlated with RVSP (rho=0.72; P=0.0027) and RVSP/systemic systolic pressure (rho=0.67; P=0.0063). Total neopulmonary artery index had a nonsignificant negative correlation with RVSP (rho=-0.42; P=0.079). Total incorporated pulmonary segments and pulmonary segment artery ratio were not correlated. Flow study mPAP had the highest accuracy in predicting successful VSD closure: area under the receiver-operator curve (0.83) versus total neopulmonary artery index (0.42), pulmonary segments (0.35), and pulmonary segment artery ratio (0.33).


CONCLUSIONS
The intraoperative pulmonary flow study predicted postoperative physiology significantly better than did standard anatomic measures. Conventional measures should be used with caution when determining the possibility for complete repair.
Honjo
Osami
O
The Labatt Family Heart Centre, The Hospital for Sick Children and the University of Toronto, Canada.
Al-Radi
Osman O
OO
MacDonald
Cathy
C
Tran
Kim-Chi D
KC
Sapra
Priya
P
Davey
Lisa D
LD
Chaturvedi
Rajiu R
RR
Caldarone
Christopher A
CA
Van Arsdell
Glen S
GS
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003097:Collateral Circulation; D005260:Female; D005500:Follow-Up Studies; D006345:Heart Septal Defects, Ventricular / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D011651:Pulmonary Artery / Q000002:abnormalities*; D018633:Pulmonary Atresia / Q000503:physiopathology / Q000601:surgery*; D011652:Pulmonary Circulation; D013599:Systole; D016278:Ventricular Function, Right