**3.1 Spiral ASO**

(Chiu et al., 2000b; Chiu et al., 2002b; Chiu et al., 2010) Figure 5 and 6 showed the techniques that restored the heart to solitus normal in Figures 1, posterior MPA could remain undivided to avoid difficult posterior hemostasis and tamponade, and bilateral hilar dissection was not necessary. In-situ repair will lessen the chance of obstruction.

Fig. 5. Technical conceptions for spiral repair (B, C, D). (A) In-situ transfer and common wall were used to redirect the left ventricular output via the old MPA stump into right and left coronary artery (RCA and LCA) as reported (Murthy and Cherian, 1996). Semiflaps were fashioned on the facing sinuses of both great arteies, creating a common arterial trunk that was then septated. Red or blue color in B, C and D indicated the final result after ASO. (B) A big MPA flap was tailored from the MPA. A pericardial patch can be used to augment this flap if the MPA is not large enough. The distal MPA (blue clay) could be reattached to the old MPA stump (red clay), at the neoaortic anastomosis site (blue/red junction marked with @) or proximal to it on the posterior wall of old MPA stump (marked with an asterisk), or remain undivided (in that case blue/red junction indicated site of neoaortic anastomosis); thus, the troublesome posterior neoaortic

(Chiu et al., 2000b; Chiu et al., 2002b; Chiu et al., 2010) Figure 5 and 6 showed the techniques that restored the heart to solitus normal in Figures 1, posterior MPA could remain undivided to avoid difficult posterior hemostasis and tamponade, and bilateral hilar

Fig. 5. Technical conceptions for spiral repair (B, C, D). (A) In-situ transfer and common wall were used to redirect the left ventricular output via the old MPA stump into right and left coronary artery (RCA and LCA) as reported (Murthy and Cherian, 1996). Semiflaps were fashioned on the facing sinuses of both great arteies, creating a common arterial trunk that was then septated. Red or blue color in B, C and D indicated the final result after ASO. (B) A big MPA flap was tailored from the MPA. A pericardial patch can be used to augment this flap if the MPA is not large enough. The distal MPA (blue clay) could be reattached to the old MPA stump (red clay), at the neoaortic anastomosis site (blue/red junction marked with @) or proximal to it on the posterior wall of old MPA stump (marked with an asterisk), or remain undivided (in that case blue/red junction indicated site of neoaortic anastomosis); thus, the troublesome posterior neoaortic

dissection was not necessary. In-situ repair will lessen the chance of obstruction.

**3. Surgical management** 

**3.1 Spiral ASO** 

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, RPA = Right Pulmonary 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 "coronary transfer".

*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 al. (1986).

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.

Restoration of Transposed Great Arteries With or Without Subpulmonary Obstruction to Nature 177

Fig. 6. (continued) Left posterior wall of MPA is not divided. Annulus near facing commissure in old aorta is xed to left anterior wall of MPA (depicted by Y stitches in inset) before incising MPA. Two J-shaped incisions are made to fashion semiflaps on facing sinuses of both great arteries. (B) A big MPA flap can be tailored from the anterior wall of huge MPA, even to its posterior aspect (black arrow, see also inset). Coronary transfer was done, using the technique in Figure 5A. A big aortic lip, redundantly covering the distal aortic orifice in picture, was taken along with the distal aorta during aortic amputation. Pink dotted line along the cut edge of the aortic lip was concordant with the light blue dotted line along the nonfacing sinus wall, and almost the whole nonfacing sinus wall was excised; the light blue arrow indicated

corresponding point of the aortic lip originally attached to the aortic sinus. Note the remaining sinus wall on the left (L) and right (R) portion of the remaining nonfacing sinus, and the light blue arrow indicated the same location through the whole Figure 6. One commissure of neoaortic valve is marked with black arrowhead. Neoaorta will sit on the pink dashed line. Aortic lip will cover the left-sided portion of neoaortic stump. (C) The distal aorta was sutured already above the neoaortic valve and coronary to LV outflow. Light blue arrow from anterior to left indicated counterclockwise rotation. Note the Hegar dilator in the RPA. After neoaortic connection and de-crossclamp, the rest of MPA cut-edge near RPA, which was shifted leftward, was attached to the posterior wall of the neoaorta (inset). Caudal edge of MPA flap can be attached at or proximal to cut edge of the old MPA stump and the aortic sinus 1 along the green dotted line (the tissue nearby is more clearly shown in B) and cut edge of the nonfacing sinus wall, which was stay-sutured and indicated here by light blue dots. (D) Attachment to form the oor of pulmonary pathway was finished. The adventitia of the aorta inside the pulmonary pathway (white asterisk) must be peeled off (Chiu et al., 2001; Chiu et al., 2010), because it will be the inner wall of future PA. Cephalic edge of anterior MPA flap can be attached to the outer wall of neoaorta directly (D inset) to roof the pulmonary pathway; ASO can be completed without any pericardial or prosthetic patch, and thus the procedure was named "arterial Senning". (L or R = Left or right portion of nonfacing sinus wall after excising the aortic lip, LV = Left Ventricle, RA = Right Atrium, RV = Right Ventricle, other

It would be interesting to see the current status of this patient 7 years after such spiral ASO

Fig. 7. Three-D CT reconstruction of the patient in Figure 6 seven years after ASO (A, B & C) showed the natural spiral relationship of the great arteries with harmonic growth of their branches. (desc = descending, LA = Left Atrium, R or L SVC = Right or Left Superior Vena Cava, other Abbreviations see Figure 5 & 6. Reproduced with permission from Chiu et al.,

Abbreviations see Figure 5)

(Figure 7).

2010)

Fig. 6. Operative techniques for spiral ASO with neo-MPA in left anterior portion. Semilunar valves are all omitted for clear illustration in all insets. (A) The aorta is located left anterior to the MPA before ASO. The aortic lip will be taken from the anterior aortic sinus wall along the light blue line on the aorta, an excision that also facilitates exposure on coronary transfer. MPA flap will be incised along the pink dotted line on the anterior MPA, yellow line on the posterior MPA (black arrow) to accommodate the ascending aorta.

Fig. 6. Operative techniques for spiral ASO with neo-MPA in left anterior portion. Semilunar valves are all omitted for clear illustration in all insets. (A) The aorta is located left anterior to the MPA before ASO. The aortic lip will be taken from the anterior aortic sinus wall along the light blue line on the aorta, an excision that also facilitates exposure on coronary transfer. MPA

flap will be incised along the pink dotted line on the anterior MPA, yellow line on the

posterior MPA (black arrow) to accommodate the ascending aorta.

Fig. 6. (continued) Left posterior wall of MPA is not divided. Annulus near facing commissure in old aorta is xed to left anterior wall of MPA (depicted by Y stitches in inset) before incising MPA. Two J-shaped incisions are made to fashion semiflaps on facing sinuses of both great arteries. (B) A big MPA flap can be tailored from the anterior wall of huge MPA, even to its posterior aspect (black arrow, see also inset). Coronary transfer was done, using the technique in Figure 5A. A big aortic lip, redundantly covering the distal aortic orifice in picture, was taken along with the distal aorta during aortic amputation. Pink dotted line along the cut edge of the aortic lip was concordant with the light blue dotted line along the nonfacing sinus wall, and almost the whole nonfacing sinus wall was excised; the light blue arrow indicated corresponding point of the aortic lip originally attached to the aortic sinus. Note the remaining sinus wall on the left (L) and right (R) portion of the remaining nonfacing sinus, and the light blue arrow indicated the same location through the whole Figure 6. One commissure of neoaortic valve is marked with black arrowhead. Neoaorta will sit on the pink dashed line. Aortic lip will cover the left-sided portion of neoaortic stump. (C) The distal aorta was sutured already above the neoaortic valve and coronary to LV outflow. Light blue arrow from anterior to left indicated counterclockwise rotation. Note the Hegar dilator in the RPA. After neoaortic connection and de-crossclamp, the rest of MPA cut-edge near RPA, which was shifted leftward, was attached to the posterior wall of the neoaorta (inset). Caudal edge of MPA flap can be attached at or proximal to cut edge of the old MPA stump and the aortic sinus 1 along the green dotted line (the tissue nearby is more clearly shown in B) and cut edge of the nonfacing sinus wall, which was stay-sutured and indicated here by light blue dots. (D) Attachment to form the oor of pulmonary pathway was finished. The adventitia of the aorta inside the pulmonary pathway (white asterisk) must be peeled off (Chiu et al., 2001; Chiu et al., 2010), because it will be the inner wall of future PA. Cephalic edge of anterior MPA flap can be attached to the outer wall of neoaorta directly (D inset) to roof the pulmonary pathway; ASO can be completed without any pericardial or prosthetic patch, and thus the procedure was named "arterial Senning". (L or R = Left or right portion of nonfacing sinus wall after excising the aortic lip, LV = Left Ventricle, RA = Right Atrium, RV = Right Ventricle, other Abbreviations see Figure 5)

It would be interesting to see the current status of this patient 7 years after such spiral ASO (Figure 7).

Fig. 7. Three-D CT reconstruction of the patient in Figure 6 seven years after ASO (A, B & C) showed the natural spiral relationship of the great arteries with harmonic growth of their branches. (desc = descending, LA = Left Atrium, R or L SVC = Right or Left Superior Vena Cava, other Abbreviations see Figure 5 & 6. Reproduced with permission from Chiu et al., 2010)

Restoration of Transposed Great Arteries With or Without Subpulmonary Obstruction to Nature 179

End to end anastomosis of the ascending aorta after excision of a segment shortened the distance between the right ventriculotomy and the PA, so that the aortic free graft could achieve its bridging effect comparable to the conventional conduit of double length without aortic shortening. This advantage of aortic shortening is also observed in patients undergoing Nikaidoh operation (Morell & Wearden, 2006). We agree with Metras and coworkers (Metras et al., 1997) that Lecompte maneuver to mobilize the pulmonary bifurcation anterior to the aorta is unnecessary. This is because if the pulmonary bifurcation is left *in situ* as it is originally by nature, the chance for developing supravalvular PS may decrease (Chiu et al., 2000b; Chiu et al., 2002b). Our direction for placement of a free graft of this curved aortic segment is opposite to that proposed by Metras (Metras et al., 1997).

Fig. 9. Three-D CT reconstruction six years after Modified Rastelli operation; no stenosis was observed at the site of free graft. The natural spiral arterial trunks with harmonic growth of

A major complication of the Rastelli operation was related to the conduit itself; crossing the midline, conduit dysfunction or valve degeneration might lead to conduit failure early or late after surgery. Our technique of recruiting autologous arterial tissue will avoid these

The natural spiral relationship of the great arteries and their branches can grow on follow-up (Figure 7 and 9). We have demonstrated that the common wall between the great arteries could grow and become thinner on follow-up (Chiu et al., 2009). Spiral reconstruction in TGA is seldom performed, because the functional implications of spiral relationship of the great arteries remain unknown; thus, the Lecompte maneuver was used either in conventional ASO or Nikaidoh and Lecompte (REV) operation (Emani et al., 2009; Morell & Wearden, 2006;

Fig. 8. (continued) The ascending aorta was amputated, and a curved segment (18 mm x 6 mm) was harvested (A) and then reconnected (B). The ventricular septal defect was rerouted to the systemic outflow with a patch. The MPA was divided and the proximal stump was closed. The aortic free graft was sutured to the distal MPA with the greater curvature on the

left (B). The lengthened MPA was then connected directly to the cephalic margin of ventriculotomy. Finally, a piece of fresh pericardium was harvested and sutured to cover the right ventricular outflow tract (C). (TAP = TransAnnular Patch, other Abbreviations see

Figures 5-7. Reproduced with permission from Chiu et al., 2009)

Follow-up CT showed satisfactory result (Figure 9).

their branches were evident. Abbreviations see Figure 7.

complications and help free the patients from reoperation.

**4. Comment** 

Between March 1998 and June 2011, spiral ASO was performed in 57 patients (38.3%), conventional nonspiral ASO with Lecompte maneuver in 92 patients (61.7%) at our hospital. The median age and weight at operation were 9 days and 3.3 kg. Cross-clamp time was significantly lower (p < 0.011) in the spiral than the nonspiral group (128 ± 36 vs 144 ± 37 minutes), because of the common wall technique in spiral ASO, wheras additional time for patch repair on defects in the sinuses of the new MPA was needed in conventional 2-vessel technique. The average follow-up was 6.9 ± 4.2 years (up to 13.5 years). Kaplan Meier survival was 94.1 ± 3.3% at 10 years and the reoperation-free rate 88.3 ± 4.5% for spiral repair. Both ratios were satisfactory and similar to those for the nonspiral group (89.6 ± 3.3% and 89.3 ± 4.1%, respectively). Signicant aortic regurgitatin in the nonspiral group (Chen et al., 2010) was not observed in the spiral group. The supravalvular PS and aortic neocoarctation that occurred in the nonspiral group (7.6% and 2.2 %, respectively) did not occur in the spiral group (0 %) (Chiu et al., 2010); these 2 complications are related to Lecompte maneuver and the unnatural relationship of the great arteries. Tiny aortopulmonary fenestration with a small left to right shunt occurred in 15 cases of spiral group (26.3%), but they closed spontaneously after a median follow up of 6 months by echo. TGA is not merely a reversal of the great arteries; nonexistence of the spiral function in TGA should be appreciated. Recognition of the spiral function and further modification might justify its future application.

#### **3.2 Modified rastelli operation**

In complete TGA with left ventricular outflow obstruction, a segment of the aorta is cut in transverse fashion and donated to the pulmonary circulation to establish the ventriculoarterial continuity (Figure 8).

Fig. 8. Operative techniques for TGA with irreparable left ventricular outflow obstruction.

Fig. 8. (continued) The ascending aorta was amputated, and a curved segment (18 mm x 6 mm) was harvested (A) and then reconnected (B). The ventricular septal defect was rerouted to the systemic outflow with a patch. The MPA was divided and the proximal stump was closed. The aortic free graft was sutured to the distal MPA with the greater curvature on the left (B). The lengthened MPA was then connected directly to the cephalic margin of ventriculotomy. Finally, a piece of fresh pericardium was harvested and sutured to cover the right ventricular outflow tract (C). (TAP = TransAnnular Patch, other Abbreviations see Figures 5-7. Reproduced with permission from Chiu et al., 2009)

End to end anastomosis of the ascending aorta after excision of a segment shortened the distance between the right ventriculotomy and the PA, so that the aortic free graft could achieve its bridging effect comparable to the conventional conduit of double length without aortic shortening. This advantage of aortic shortening is also observed in patients undergoing Nikaidoh operation (Morell & Wearden, 2006). We agree with Metras and coworkers (Metras et al., 1997) that Lecompte maneuver to mobilize the pulmonary bifurcation anterior to the aorta is unnecessary. This is because if the pulmonary bifurcation is left *in situ* as it is originally by nature, the chance for developing supravalvular PS may decrease (Chiu et al., 2000b; Chiu et al., 2002b). Our direction for placement of a free graft of this curved aortic segment is opposite to that proposed by Metras (Metras et al., 1997). Follow-up CT showed satisfactory result (Figure 9).

Fig. 9. Three-D CT reconstruction six years after Modified Rastelli operation; no stenosis was observed at the site of free graft. The natural spiral arterial trunks with harmonic growth of their branches were evident. Abbreviations see Figure 7.

A major complication of the Rastelli operation was related to the conduit itself; crossing the midline, conduit dysfunction or valve degeneration might lead to conduit failure early or late after surgery. Our technique of recruiting autologous arterial tissue will avoid these complications and help free the patients from reoperation.
