Abstract
Objectives: Since 2007, the EVAR (endovascular abdominal aortic repair) grafts, Zenith, Excluder and Powerlink had been commercially available in Japan. However, a small iliac artery, typical of Japanese population especially in women, was a limiting factor to indicate EVAR. We analyzed the suitability of EVAR in Japanese population according to the inclusion criteria of Zenith AAA stent graft in the current study.
Methods: From January 2006 to December 2007, 106 AAA (abdominal aortic aneurysm) patients (88 men, 18 women) with a mean age of 73 years were investigated in our institution by multi-slice CT scan in terms of suitability of EVAR, then we measured their abdominal aorta and iliac artery parameters as follows; 1) proximal neck diameter (PND) and length (PNL), 2) common iliac artery diameter (CIAD) and length (CIAL), 3) suprarenal (SNA) and infrarenal neck angulation (INA), 4) external iliac artery diameter (EIAD) and 5) aortic length from the lowest renal artery to the aortic bifurcation (AOL). The inclusion criteria for Zenith AAA stent graft treatment were; A) PND: 18–28 mm, PNL more than 15 mm, B) unilateral CIAD less than 20 mm, CIAL at least 10 mm, C) SNA less than 45 degree and INA less than 60 degree, D) unilateral EIAD more than 7.5 mm.
Results: The indication of EVAR was 25.5% (27 / 106 patients), and was especially very low in women (5.6%) strictly according to the inclusion criteria of the Zenith AAA stent graft. The main reason of exclusion of EVAR was proximal short neck (40.5%), small iliac artery (30.4%) and infrarenal aortic neck angulation (29.1%). In our analysis, female AAA patients had small PNL and EIAD with angulated neck compared with male AAA ones.
Conclusions: Anatomical suitability of EVAR in Japanese population strictly following by the inclusion criteria of Zenith AAA stent graft was low due to their characteristic differences from EU and US patients, such as short proximal neck, steep neck angulation and small iliac artery, especially in women. More flexible or branched/fenestrated grafts with a low profile sheath may be essential to be indicated EVAR in more Japanese AAA patients.
