Impaired distensibility of neoaorta after arterial switch procedure

Background. Although the arterial switch operation has become the standard surgical procedure for treatment of complete transposition, postoperative problems have not been fully appreciated. One such problem may be the postoperative function of great arteries that are manipulated radically. Methods. The diameters at four levels of the aorta were measured in 36 patients who had undergone arterial switch operation and the distensibilities were calculated. The data were compared with that of age-matched controls. Results. At the level of the Valsalva sinus, aortic diameters after one-staged and two-staged operations were 137.0% ± 21.3%N and 152.4% ± 17.7%N of the normal aorta, respectively. The distensibilities at the Valsalva sinus in patients after one-staged and two-staged operations were 1.2 ± 0.7 and 1.5 ± 0.8 cm2 • dyn−1 • 10−6, and at the supraaortic ridge were 2.5 ± 1.5 and 1.9 ± 1.5 cm2 • dyn−1 • 10−6, respectively. Conclusions. In patients after arterial switch procedure, the distensibility of the base of aorta is decreased. Long-term follow-up is necessary to clarify the influence of the “stiffness” of the base of aorta.