**2.5 Bronchus**

172 Front Lines of Thoracic Surgery

Fig. 2. Our studies on 101 angiograms showed the wider the main to branch PA angle, the better PA size. Narrow L/R PA angle resulted in bilateral PA hypoplasia in the upper panel. Thus wider angle facilitates bilateral PA growth before ASO. Any maneuver that did not correct this inborn error of ventriculoarterial discordance or make even narrower angle like

The aortic arch is kept wide open by the presence of the MPA bifurcation below it (Chiu et al., 2000b; Chiu et al., 2002b). Neo-aortic kinking is the narrowing of the aortic arch window and may become slit-like, can also be called aortic neocoarctation (Figure 3, Chiu et al., 2010; Muster et al., 1987). One group reported an incidence of 0.54% (Serraf et al., 1995). A coarctation is not present and the arch is wide open before conventional ASO with Lecompte maneuver. A pressure gradient across it is rare, less seen than is supravalvular PS

Fig. 3. After conventional arterial switch with Lecompte maneuver, a slit like arch window

can be seen in the right panel, which was wide open before switch.

Lecompte maneuver will compromise PA growth.

because of systemic-pressure in aorta.

**2.4 Aorta** 

The aorta is not the only structure behind the MPA bifurcation after Lecompte maneuver, the left main bronchus (airway-pressure with cartilage) is also present. Bronchial compression or even atelectasis has been reported after Lecompte maneuver (Robotin et al., 1996; Toker et al., 2000), although in the majority of cases the bcronchial patency was not so severely compromised.

Fig. 4. After conventional ASO with Lecompte maneuver, not only supra-aortic stenosis occurs at the site posterior to the anteriorly mobilized pulmonary bifurcation (\*), but also the left main brobchus, that is cartilage stented, is ccompreesed; its lumen becomes pin hole like on brochoscope, both virtual and real. In the right lower panel, the aortic arch window becomes slit-like at lesser curvature site.

Restoration of Transposed Great Arteries With or Without Subpulmonary Obstruction to Nature 175

Fig. 5. (continued) anastomosis site bleeder can be drained into PAs. Nonfacing sinus was cut open for exposure during coronary transfer. (C) The transparent ascending aorta, with a left aortic lip (procured by oblique amputation of aorta, Chiu et al., 2000b), was rotated counterclockwise to sit on the neoaortic stump. The posterior cut-edge of MPA could be attached to the posterior neoaorta at this stage as leftward as possible.(D) The RPA orifice must be visible behind the aorta to ensure patency of RPA, not just probed with a Hegar dilator. A big enough MPA flap could be reattached to the neoaorta without pericardial patch. (Ao = Aorta, L or R = Left or Right portion of nonfacing sinus wall after cut back, LCA = Left Coronary Artery, LPA =Left Pulmonary Artery, RCA = Right Coronary Artery,

No-fault transfer of the coronary artery is the cornerstone of a successful ASO. Various techniques (Aubert et al., 1978; Yacoub and Randly Smith, 1978; Kurosawa et al., 1986; Quaegebeur et al., 1986; Brawn and Mee, 1988; Idriss et al., 1988; Bove et al., 1989; Takeuchi and Katogi, 1990; Mee, 1994; de Leval et al., 1994; Murthy & Cherian, 1996; Chiu et al., 1996a & 1997) have been proposed to achieve this goal: de Leval et al. (1994) pointed out that the key point is to take the aorta away from the coronary arteries and the MPA is brought to them, rather than moving the coronaries from the aorta and transferring the coronary scallops to the MPA or neoaorta. To implement this concept, *in situ* transfer technique, proposed by Aubert et al. (1978) and Takeuchi and Katogi (1990), was developed by Murthy and Cherian (1996). This principle is the key (Figure 5) we adopted to redirect the neoaortic outflow tract to the coronary arteries as *in situ* as possible by a common wall concept. In this way the coronary redirection can be achieved more securely than the conventional

*In situ* transfer and the common wall concept not only for the coronary arteries, but also for both great arteries are our guiding principle. We have designed two pedicled grafts, aortic lip and MPA flap, to achieve our goal. The purpose of these two flaps is described below. The aortic lip (Figures 2, 3A and 3B) is initially called left lip (Chiu et al., 2002b). In our first spiral arterial switch, we used a free flap taken from MPA to cover the left-sided portion of the neoaortic stump (Chiu et al., 2000b), to solve the size discrepancy when connecting small aorta to a very large, original MPA stump; the other effect is to act as the floor of the neopulmonic pathway. Since the nonfacing aortic sinus was cut back (Figure 5B and 5C) for exposure during coronary transfer, later we used an aortic pedicled graft including the nonfacing aortic sinus wall (Figure 6A and 6B) to achieve the above 2 purposes of the aortic lip. In addition, using the aortic lip taken from **anterior** sinus wall to cover the **left-sided** portion (Figure 6B and 6C, light blue arrow), we can achieve the effect of counterclockwise rotation of the ascending aorta. This, in turn, would give way to the RPA so that it can sling around the ascending aorta (Figure 6C, Hegar dilator in RPA). The fourth effect of the aortic lip might lessen the chance of coronary kinking by avoiding take-up the larger stump on neoaortic anastomosis, as noted by Quaegebeur et

The purposes of the MPA flap include: (1) accommodating the ascending aorta, (2) achieving a more leftward shift of RPA, and (3) attaching to the ascending aorta without pericardium. Thus, the spiral relationship of the great arteries is resumed by using the

autologous pedicled flaps tailored from both arterial trunks, respectively.

RPA = Right Pulmonary Artery)

"coronary transfer".

al. (1986).
