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Editor,—Most of the patients in the article “Stenting for middle aortic syndrome” by Rajszys et al had long lesions with significant peak systolic gradients across the stenotic segment. Primary stenting of the lesions significantly reduced the peak systolic gradients.1 We fail to understand the authors’ preference for anticoagulants over ticlopidine. Studies have consistently shown that use of antithrombotic drugs are far superior to anticoagulants, not only in lowering the incidence of stent thrombosis but also in preventing bleeding complications.2 The use of anticoagulants has largely been abandoned worldwide, even in coronary vessels, which have much smaller luminal diameters and lower flow rates compared with the aorta where the risk of thrombosis is low because of large lumen and higher flow rates.
Second, Rajszys et al deployed the Palmaz Schatz stents suboptimally to avoid overdilatation of aorta, repeating the procedure after the intimal tears have healed. Laplace’s law theoretically places the aorta at an increased risk for rupture during angioplasty because less pressure is required to dilate the arterial walls as the diameter of the artery increases.3 Hence, overdilatation of the aorta must never be attempted. Use of balloons sized 60–100% of the normal looking aorta and less than three times the maximally constricted segment have been shown to be safe and effective for aortoplasty.4 Higher pressures are required in some cases for an optimal result. This is especially true for cases of middle aortic syndrome due to Takayasu arteritis (TA) where the vessel wall is thick and fibrosed. A similar strategy was used by Tyagiet al in their series of 38 cases of aortoplasty in TA including cases of middle aortic syndrome.5 In our experience of de novo stenting of descending thoracic aorta in four cases of TA, we have shown that optimal deployment of Wall stents (Schneider Inc, Minneapolis, Minnesota, USA) using high pressure inflation (12–16 atm) could significantly increase the luminal diameters and abolish the peak systolic gradients.6 We did not observe any case of stent thrombosis or any significant injury to the vessel wall. We feel that optimal deployment of stents would not only avoid stent thrombosis as occurred in one case in this series, but also avoid exposure to increased afterload and its adverse haemodynamic effects. It will also avoid the need for more procedures, limit fluoroscopic exposure, and prevent unnecessary hospital expenses. Even in children, stents can be safely deployed, taking into consideration the diameter of the normal aorta. These stents may be further dilated as the child grows.
Third, regarding the choice of stents: we feel that self expanding stents are preferable in long lesions of descending thoracic aorta to the Palmaz Schatz stent. They adapt to the anatomy of the aorta better and avoid deployment of several stents in long diffuse lesions.