Comparison of shunt types in the Norwood procedure for single-ventricle lesions.
BACKGROUND
The Norwood procedure with a modified Blalock-Taussig (MBT) shunt, the first palliative stage for single-ventricle lesions with systemic outflow obstruction, is associated with high mortality. The right ventricle-pulmonary artery (RVPA) shunt may improve coronary flow but requires a ventriculotomy. We compared the two shunts in infants with hypoplastic heart syndrome or related anomalies.


METHODS
Infants undergoing the Norwood procedure were randomly assigned to the MBT shunt (275 infants) or the RVPA shunt (274 infants) at 15 North American centers. The primary outcome was death or cardiac transplantation 12 months after randomization. Secondary outcomes included unintended cardiovascular interventions and right ventricular size and function at 14 months and transplantation-free survival until the last subject reached 14 months of age.


RESULTS
Transplantation-free survival 12 months after randomization was higher with the RVPA shunt than with the MBT shunt (74% vs. 64%, P=0.01). However, the RVPA shunt group had more unintended interventions (P=0.003) and complications (P=0.002). Right ventricular size and function at the age of 14 months and the rate of nonfatal serious adverse events at the age of 12 months were similar in the two groups. Data collected over a mean (+/-SD) follow-up period of 32+/-11 months showed a nonsignificant difference in transplantation-free survival between the two groups (P=0.06). On nonproportional-hazards analysis, the size of the treatment effect differed before and after 12 months (P=0.02).


CONCLUSIONS
In children undergoing the Norwood procedure, transplantation-free survival at 12 months was better with the RVPA shunt than with the MBT shunt. After 12 months, available data showed no significant difference in transplantation-free survival between the two groups. (ClinicalTrials.gov number, NCT00115934.)
Ohye
Richard G
RG
University of Michigan Medical School, Ann Arbor, MI, USA. ohye@umich.edu
Sleeper
Lynn A
LA
Mahony
Lynn
L
Newburger
Jane W
JW
Pearson
Gail D
GD
Lu
Minmin
M
Goldberg
Caren S
CS
Tabbutt
Sarah
S
Frommelt
Peter C
PC
Ghanayem
Nancy S
NS
Laussen
Peter C
PC
Rhodes
John F
JF
Lewis
Alan B
AB
Mital
Seema
S
Ravishankar
Chitra
C
Williams
Ismee A
IA
Dunbar-Masterson
Carolyn
C
Atz
Andrew M
AM
Colan
Steven
S
Minich
L LuAnn
LL
Pizarro
Christian
C
Kanter
Kirk R
KR
Jaggers
James
J
Jacobs
Jeffrey P
JP
Krawczeski
Catherine Dent
CD
Pike
Nancy
N
McCrindle
Brian W
BW
Virzi
Lisa
L
Gaynor
J William
JW
D006348:Cardiac Surgical Procedures / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D018610:Heart Bypass, Right / Q000379:methods*; D016027:Heart Transplantation / Q000706:statistics & numerical data*; D006352:Heart Ventricles / Q000002:abnormalities* / Q000601:surgery*; D006801:Humans; D018636:Hypoplastic Left Heart Syndrome / Q000401:mortality / Q000601:surgery*; D007231:Infant, Newborn; D057194:Intention to Treat Analysis; D053208:Kaplan-Meier Estimate; D008297:Male; D011183:Postoperative Complications; D016016:Proportional Hazards Models; D011651:Pulmonary Artery / Q000601:surgery*