Transverse arch hypoplasia is an integral, albeit anatomically independent, part of neonatal coarctation of the aorta.¹ Extended end to end anastomosis has been advocated to overcome arch hypoplasia.² Numerous studies demonstrated the growth potential of the aortic arch following repair with confined extensity.^3–5 Limited information, however, is available on how rapidly the hypoplastic aortic arch adapts to post-coarctectomy circulatory conditions. The purpose of this study is to demonstrate that a hypoplastic transverse arch not addressed surgically, remodels to entertain increasing cardiac output in the early postoperative period.

PATIENTS AND METHODS

Thirty four consecutive infants (19 boys and 15 girls; mean (SD) age 13.1 (6.19) days (range 1–58 days); mean weight 2.8 (0.53) kg (range 1.1–4.6 kg)) underwent coarctation repair as primary operation at our institution, forming the patient group of this study.

Diagnoses were established by two dimensional Doppler echocardiography (Sonos 5500, 7.5 MHz, Hewlett-Packard, Andover, MA) using standard projections. Internal diameters of the distal transverse aortic arch (distal to left carotid artery) and descending aorta (at the level of the diaphragm) were measured and this ratio was chosen to express the degree of transverse arch hypoplasia (a ratio of < 0.5 was considered hypoplastic).³ Patients were grouped as normal and hypoplastic arch groups according to arch ratio.

From left posterolateral thoracotomy the transverse aortic arch and its branches, arterial …