Takashi Yamauchi1, Hiroshi Takano2, Toshiki Takahashi3, Takafumi Masai4, Masayuki Sakaki5, Yukitoshi Shirakawa6, Katsukiyo Kitabayashi5, Naoki Asano2, Koichi Toda7, Yoshiki Sawa7. 1. Department of Cardiovascular Surgery, Dokkyo Medical University Saitama Medical Center, Saitama, Japan; Department of Cardiovascular Surgery, Sakurabashi Watanabe Hospital, Osaka, Japan. Electronic address: yamataka@surg1.med.osaka-u.ac.jp. 2. Department of Cardiovascular Surgery, Dokkyo Medical University Saitama Medical Center, Saitama, Japan. 3. Department of Cardiovascular Surgery, Osaka Police Hospital, Osaka, Japan. 4. Department of Cardiovascular Surgery, Sakurabashi Watanabe Hospital, Osaka, Japan. 5. Department of Cardiovascular Surgery, Osaka National Hospital, Osaka, Japan. 6. Department of Cardiovascular Surgery, Osaka General Hospital, Osaka, Japan. 7. Department of Cardiovascular Surgery, Osaka University Graduate School of Medicine, Osaka, Japan.
Abstract
BACKGROUND: A successful endovascular treatment for acute type A dissection has been recently reported. However, there has been no consensus regarding the appropriate stent graft size based on the estimated predissected aortic diameter for this pathology. METHODS: We developed new equations for estimating the predissected ascending aorta and aortic arch by investigating computed tomography images that had been scanned less than 3 years before dissection. From 684 patients with type A AAD, 28 were matched for the study. We measured the predissected whole circumference length (pre-wCL), postdissected whole circumference length (post-wCL), postdissected true lumen circumference length (post-tCL), postdissected major diameter (post-Dma), and postdissected minor diameter (post-Dmi) of the acutely dissected aorta. This was followed by the calculation of (post-tCL + post-wCL)/2 and (post-Dma + post-Dmi)/2. Six equations (linear function) and modified equations were derived from each of the abovementioned parameters. RESULTS: Four equations (post-wCL, post-Dma, [post-tCL + post-wCL]/2, and [post-Dma + post-Dmi]/2) had nearly the same bias and accuracy (<9.42 mm). For clinical use, we also developed one modified equation using the post-wCL (y = 0.9x) among four parameters because of its simplicity and decreased the possibility of measurement error. The biases of circumference length and accuracy were 5.5 ± 4.9 mm and 84.6%, respectively, and they improved to 4.4 ± 3.3 mm and 93.4% in cases with a ratio of post-tCL/post-wCL of 0.66 or more. CONCLUSIONS: Our newly developed equation can be used to calculate the predissected ascending aortic diameter and aortic arch diameter in cases of acute type A dissection.
BACKGROUND: A successful endovascular treatment for acute type A dissection has been recently reported. However, there has been no consensus regarding the appropriate stent graft size based on the estimated predissected aortic diameter for this pathology. METHODS: We developed new equations for estimating the predissected ascending aorta and aortic arch by investigating computed tomography images that had been scanned less than 3 years before dissection. From 684 patients with type A AAD, 28 were matched for the study. We measured the predissected whole circumference length (pre-wCL), postdissected whole circumference length (post-wCL), postdissected true lumen circumference length (post-tCL), postdissected major diameter (post-Dma), and postdissected minor diameter (post-Dmi) of the acutely dissected aorta. This was followed by the calculation of (post-tCL + post-wCL)/2 and (post-Dma + post-Dmi)/2. Six equations (linear function) and modified equations were derived from each of the abovementioned parameters. RESULTS: Four equations (post-wCL, post-Dma, [post-tCL + post-wCL]/2, and [post-Dma + post-Dmi]/2) had nearly the same bias and accuracy (<9.42 mm). For clinical use, we also developed one modified equation using the post-wCL (y = 0.9x) among four parameters because of its simplicity and decreased the possibility of measurement error. The biases of circumference length and accuracy were 5.5 ± 4.9 mm and 84.6%, respectively, and they improved to 4.4 ± 3.3 mm and 93.4% in cases with a ratio of post-tCL/post-wCL of 0.66 or more. CONCLUSIONS: Our newly developed equation can be used to calculate the predissected ascending aortic diameter and aortic arch diameter in cases of acute type A dissection.