Reverse Subclavian Flap Repair for Coarctation with Hypoplastic Arch

The child should be positioned with the left side up in the right lateral decubitus position. Ideally the arterial monitoring catheter should be inserted in the right radial artery. Pulse oximeter probes should be placed on the right hand and on one of the lower extremities. The child should be placed on the cooling/warming blanket to allow manipulation of body temperature. In general, it is advisable to maintain the rectal temperature between 34 to 35°C during the cross-clamp period. A left posterior (rather than posterolateral) thoracotomy incision is performed and the chest is entered through the third or fourth intercostal space.

The left lung is retracted anteriorly with malleable retractors. Generally one malleable retractor is placed above the hilum of the lung to retract the upper lobe while a second malleable retractor is placed below the hilum of the lung to retract the lower lobe. A moist sponge stretched across the hilum between the two retractors protects the lung and prevents slipping of the malleable retractor.

First clamp phase: reverse subclavian flap. A clamp is placed across the aortic isthmus in such a way that continuing perfusion of the distal body will occur through the patent ductus. Usually, a slightly angled clamp or an aortic cross-clamp style of clamp is appropriate for clamping the isthmus. A “C” clamp is placed across the proximal aortic arch and incorporates the left common carotid artery, which should be clamped across its middle. By this time the left subclavian artery has been ligated distally. It is not considered essential that the vertebral artery branch of the left subclavian artery should be ligated, although there is a theoretical risk of a subclavian steal phenomenon developing.

After division of the left subclavian artery, it is filleted open along its rightward face, i.e., the side of the subclavian artery that faces toward the common carotid artery. The incision is carried across the superior surface of the distal aortic arch and then turns cephalad along the leftward face of the left common carotid artery over a distance of 3 to 4 mm.

The left subclavian artery is now turned down as a flap with the toe of the flap being sutured initially to the most distal extent of the incision in the left common carotid artery. The posterior wall of the flap can be sutured from within the lumen using continuous 6/0 Prolene. The anterior layer is then completed using the same suture.

After release of the clamps, perfusion is reestablished to the left common carotid artery. Perfusion continues through the ductus.

Second clamp phase: resection of coarctation. The ductus arteriosus is ligated with a 5/0 Prolene suture ligature. A distal clamp is applied across the most distal extent of dissection of the descending aorta with the clamp incorporating the proximal intercostal vessels. In the neonate, these vessels are sufficiently thick-walled and elastic to allow composite clamping with the descending aorta. The proximal clamp is applied across the newly enlarged distal aortic arch, with flow maintained through the left common carotid artery.

The juxtaductal coarctation is now excised though the isthmic segment does not need to be removed with the excised specimen. It is preferable to perform a slide plasty advance of the descending aorta and use the tissue of the isthmic segment. An incision is extended from the point of division of the distal isthmus across the inner curve of the aorta to the undersurface of the newly enlarged distal aortic arch. A longitudinal incision is made in the descending aorta on its outer curve, i.e., the leftward face of the descending aorta. The length of the incision should be adequate to match the circumference of the ascending aorta with the length of the aortotomy in the isthmus and undersurface of the distal aortic arch.

The anastomosis is now fashioned using continuous 6/0 Prolene beginning with an inside-to-outside suture on the distal aortic arch with the same needle being brought outside to inside on the distal aorta. The posterior wall should be run first and then the other needle of the same suture should be brought across the anterior wall of the anastomosis. It is particularly important to take care with the toe of the anastomosis. Closely spaced bites should be taken proximally with wider spaced bites being taken on the descending aorta.

The repair has been completed. After release of the clamps the patient’s body temperature should be gradually returned toward normothermia. Aggressive rewarming should be avoided.