'Less patch more growth?': comparing two different schools of thought in aortic arch reconstruction techniques during Norwood I

Background: We compared two different philosophies at one institution with respect to arch-geometry and clinical results: no/minimal patch vs. abundant patch augmentation. Methods: Single center retrospective analysis of the interstage angiographies of 82 patients: 41 (50%) underwent stage I Norwood-type palliation with minimal/no patch material for arch augmentation (Group 1, 2001-2011), and 41 (50%) with an abundant use of patch material (Group 2, 2011-2019). Aortic arch angle, distal arch:descending ratio, planimetry of whole arch, left hilar space were quantified. Clinical endpoints were all interstage interventions on the aortic arch, left pulmonary artery and readmissions due to left lung atelectasis and respiratory failure. Results: Arch angles were more acute in Group 1 (81°±13,2 vs. 90°±10,28, P = .012), with no difference in left hilar space (0,28±0,08 vs. 0,29±0,06, P = .43). Distal arch:descending ratio was smaller in Group 1 (0,72±0,2 vs 0,86±0,19, P = .04). Interstage interventions on the aortic arch and descending aorta were provided in 17 (41,5%) patients in Group 1 versus 19 (46,3%) patients in Group 2. Transcatheter interventions on the left pulmonary artery were necessary in 18 Group 1 patients versus 18 Group 2 patients (43,9%). Unilateral left lung atelectasis and respiratory failure occurred in 2 patients (4,4%) in Group 1 and in 3 patients (7,3%) in Group 2. Conclusions: Abundant patch material is associated with less acute aortic arch angles and leads to significantly better distal arch growth. However, this theoretical geometric benefit did not lead to greater left hilar space, nor did it prove to be superior with respect to interstage-interventions on left hilar structures. Mid-term no clinical effect was detected but future long-term effects are substantial.