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Influence of pulmonary artery size on early outcome after the Fontan operation
Anja Lehner1, Anna Schuh1, Florian E M Herrmann1
1Department of Pediatric Cardiology and Pediatric Intensive Care, University Hospital Munich, Ludwig Maximilian University, Munich, Germany.
Insights
Pulmonary artery size is not a significant factor impacting early outcomes after the Fontan operation (FO). This study suggests that delaying FO due to small pulmonary arteries (PAs) may not be necessary.
Area of Science:
- Pediatric Cardiology
- Congenital Heart Disease
- Surgical Outcomes
Background:
- Small pulmonary arteries (PAs) have traditionally been a contraindication for the Fontan operation (FO).
- The impact of PA size on early postoperative outcomes following FO requires re-evaluation.
Purpose of the Study:
- To determine if pulmonary artery size remains a critical factor influencing early outcomes after the Fontan operation.
- To assess the risk associated with smaller pulmonary arteries in patients undergoing Fontan procedures.
Main Methods:
- Retrospective analysis of 146 patients who underwent a modified Fontan operation.
- Evaluation using traditional McGoon ratio, Nakata index, and modified indices measuring narrowest PA diameters.
- Analysis correlated PA size metrics with mechanical ventilation duration, ICU stay, hospital stay, and effusions.
Main Results:
- Patients with smaller pulmonary arteries (based on McGoon ratio ≤1.6 or Nakata index ≤150 mm²/m²) did not exhibit higher risks of prolonged mechanical ventilation, ICU stay, hospital stay, or effusions.
- Younger age (<24 months) and lower weight (<12 kg) were not predictive of poor early postoperative outcomes, despite a tendency for smaller PAs in younger/smaller children.
Conclusions:
- Small pulmonary arteries do not significantly impact the early postoperative period following the Fontan operation.
- Postponing the Fontan operation solely due to small pulmonary arteries is likely unnecessary.
- Palliative procedures to increase PA size must be carefully weighed against risks like single ventricle volume overload and prolonged cyanosis.
Background:
Small pulmonary arteries (PAs) are often considered as a contraindication for the Fontan operation (FO). The aim of this study was to evaluate if the PA size is still one of the major impact factors on the postoperative early outcome.
Methods:
Data of 146 patients, with a median age of 2.0 years (range, 1.5 to 18 years) and a median weight of 12.45 kg (range, 7.7 to 64.7 kg) who underwent a modified FO in the same center between 2007 and 2012 were retrospectively analyzed with respect to the traditional McGoon ratio, Nakata index, and modified indices (measuring the narrowest diameters).
Results:
Patients with a McGoon ratio of 1.6 or less (modified≤1.2) or a Nakata index of 150 mm2/m2 or less (modified≤100 mm2/m2) were not at a higher risk of longer mechanical ventilation (p=0.87 [0.1] and p=0.68 [0.52], respectively), longer stay (p=0.52 [0.18] and p=0.54 [0.38], respectively) in the intensive care unit, prolonged hospital stay (p=0.08 [0.26] and p=0.22 [0.29], respectively) or effusions (p=0.25 [0.37] and p=0.13 [0.06]), respectively). Younger and smaller children tended to have smaller PAs, but younger age (<24 months) and lower weight (<12 kg) were not predictive for poor early postoperative outcome.
Conclusions:
Small PAs do not significantly affect the early postoperative period after FO. In our opinion, there is no need to postpone the FO due to "smaller" PAs. The palliative procedures performed before FO to increase the size of the PA at the expense of volume overload of the single ventricle and the possible complications of prolonged cyanosis must be carefully weighed.
