Intermediate Results of Hybrid Versus Primary Norwood Operation

Ann Thorac Surg. 2015 Jun;99(6):2141-7; discussion 2147-9. doi: 10.1016/j.athoracsur.2015.02.025. Epub 2015 Apr 15.


Background: In 2007 we began a hybrid program for hypoplastic left heart syndrome (HLHS) variants to potentially improve outcome in high-risk patients. During implementation we offered both hybrid and Norwood approaches to all risk categories. The purpose of this study was to perform a comparative analysis of intermediate survival.

Methods: Newborns were evaluated jointly for high-risk characteristics, including birth weight less than 2.5 kg, prematurity (especially < 35 weeks), central nervous system abnormalities, multiorgan failure, intact or severely restrictive atrial septum, severe ventricular dysfunction, and severe atrioventricular valve regurgitation. We prefer Norwood for standard risk and hybrid for high risk, but all groups crossed over into all treatment pathways resulting in the following 5 treatment groups: standard risk Norwood; high-risk Norwood; standard risk hybrid ductal stent (HDS); high-risk hybrid DS; and high-risk hybrid prostaglandin E1 (HPGE). We reviewed all consecutive patients from 2007 to 2012, obtained follow-up, and analyzed the results.

Results: Sixty-eight newborns presented (median 2.96 kg, 8 days); 29 (43%) were high and 39 (57%) were standard risk. There were 14 stage I hospital deaths strongly associated with risk: 3 of 39 standard (7.7%) and 11 of 29 high (38%, p = 0.002). Stage I discharge mortality was highest for high-risk Norwood and high-risk HPGE groups (p < 0.001). Actuarial survival up to 5 years demonstrated superior survival for Norwood versus hybrid (78.1% vs 56.4%, p = 0.0182). With risk stratification there was suboptimal survival for all 3 high-risk groups (p = 0.003); HDS fared better than HPGE but had higher birth weight (p < 0.001).

Conclusions: While a risk-stratified approach for HLHS variant patients with selective use of hybrid palliation resulted in acceptable stage I mortality, the longer term mortality for high-risk patients remains higher than for standard risk regardless of treatment modality. Intrinsic patient risk factors (rather than treatment modality) likely determine long-term outcome in experienced centers. Our current high-risk approach has evolved to HPGE application with Norwood conversion whenever deemed medically possible.

MeSH terms

  • Blood Vessel Prosthesis*
  • California / epidemiology
  • Ductus Arteriosus / surgery*
  • Female
  • Follow-Up Studies
  • Humans
  • Hypoplastic Left Heart Syndrome / mortality
  • Hypoplastic Left Heart Syndrome / surgery*
  • Infant
  • Infant, Newborn
  • Male
  • Norwood Procedures*
  • Palliative Care / methods
  • Pulmonary Artery / surgery*
  • Risk Factors
  • Survival Rate / trends
  • Time Factors
  • Treatment Outcome