A study of 129 newborns with critical congenital heart disease found that 21.7% died during the neonatal period after undergoing a modified Blalock-Taussig shunt (MBTS), a procedure used in this setting. Mortality was 66.7% among babies whose shunt failed, compared with 11.6% among those without failure.
The result is an association, not evidence that shunt failure caused death. Because researchers looked back at records from one center, the study cannot establish cause and effect.
Records from one specialist center
Researchers reviewed electronic medical records from a Level III neonatal intensive care unit at a tertiary referral center for congenital heart disease in Ankara, Türkiye. The babies underwent MBTS between January 2011 and December 2021.
After eight neonates were excluded, 129 remained. Of these, 61 had single-ventricle physiology and 68 had biventricular physiology. Two died during the operation, leaving 127 for postoperative-outcome and shunt-failure analyses.
Shunt failure was defined as complete blockage or critical narrowing confirmed by echocardiography. Early neonatal mortality meant death within the first 30 days of life or before discharge from intensive care.
The sharpest divide came when the shunt failed
Shunt failure occurred in 24 of the 127 babies transferred to intensive care after surgery, or 18.9%. Mortality in the failure group was 66.7%, versus 11.6% among babies without failure; the reported difference had a p-value of 0.001.
Preoperative hematocrit, a blood measurement taken before surgery, was the only measure with acceptable discrimination for shunt failure. A cutoff of 36.35% identified 91.7% of failures, while correctly classifying 51.4% of babies who did not have shunt failure.
Several factors appeared together
A model that assessed several factors together identified lower gestational age, preoperative inotropic support, preoperative mechanical ventilation, shunt failure and postoperative acidosis as independent predictors of neonatal mortality. The reported odds ratios were 0.82, 3.46, 4.28, 5.12 and 6.78, respectively.
These figures describe statistical associations in this cohort. Given the retrospective design, they do not show that changing any one of the factors would prevent death.
What happened after the operation
Early postoperative complications included pulmonary hemorrhage, sepsis, ventilator-associated pneumonia and acute kidney injury requiring peritoneal dialysis. The records also listed one case each of multiple-organ dysfunction syndrome, necrotizing enterocolitis, diaphragmatic paralysis, and intracranial hemorrhage with seizures.
Among the 101 babies who survived to intensive-care discharge, follow-up was available for the majority. Seven died within the first 24 months after discharge before a planned second-stage surgical procedure.
Surgical follow-up records showed that 57 patients underwent a bidirectional Glenn procedure and five underwent primary corrective surgery.
The review reported no significant mortality difference between babies with single-ventricle and biventricular physiology. Among infants with syndromic diagnoses, five of nine died, or 55.5%.
Why the findings need careful reading
The study provides outcome estimates from a retrospective cohort at one tertiary referral center. Its results identify patterns associated with mortality among babies who underwent MBTS, but they do not establish cause and effect or show which treatment changes would improve survival.
Paper data and sources
Original title: Unveiling prognostic factors in neonatal modified Blalock-Taussig shunt procedures: a comprehensive single-center analysis
Authors: Akduman H, Dilli D, Kaya B et al.
Journal/Repository: Revista da Associacao Medica Brasileira (1992)
Status: Peer-reviewed
First online: 2026-08-19
DOI: Not available
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