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Updated: Aug 7, 2026

Surgical Swine Model of Chronic Cardiac Ischemia Treated by Off-Pump Coronary Artery Bypass Graft Surgery
Published on: March 27, 2018
Excision of the coronary orifices in arterial switch operation: "O" like obstructive and "U" like unobstructive?
W Beierlein1, H-P Freitag, S Salehi-Gilani
1Department of Thoracic, Cardiac and Vascular Surgery, Tübingen University Hospital, Tübingen, Germany.
Background:
Stenoses of the neo-pulmonary artery (NPA) may complicate follow-up of the arterial switch operation (ASO). It is unknown whether the type of patch covering the coronary excision defects ("O"- or "U"-shaped) might influence this complication.
Methods:
Echocardiographically and invasively measured NPA pressure-gradients were evaluated retrospectively in 95 children after ASO. Median follow-up was 5.8 years. Defects had been covered with pericardial patches: O/O and U/U (left/right) 34 x each, and 27 x in mixed combinations. The frequency of NPA stenoses requiring re-interventions was registered.
Results:
Median of the peak instantaneous echocardiographic pressure gradient was 23 mmHg (interquartile range, IQR: 16 - 49, n = 34) in O/O, and 19 mmHg (IQR: 13 - 23, n = 34) in U/U; p < 0.034, t-test. Invasively measured gradients were 49 mmHg (IQR: 17 - 65, n = 12) in O/O, and 12 mmHg (IQR: 7-21, n = 28) in U/U; p < 0.001. One child per O/O- and U/U-group underwent balloon angioplasty of the neo-pulmonary root. Five children of the O/O-group had to undergo repeat surgery, whereas only one child in the U/U-group required repeat surgery ( p < 0.34).
Conclusions:
The preferential type of covering the NPA coronary excision sites in ASO should be U-shaped.

