Surgeon-Modified Zenith Stent Graft System for Endovascular Repair of Abdominal Aortic Aneurysm with Short Proximal Neck / 日本心臓血管外科学会雑誌

ABSTRACT

Endovascular repair for abdominal aortic aneurysm (EVAR) has become widespread in Japan because of its low invasiveness. However adequate proximal neck length is required for EVAR. Unfortunately the surgical mortality of para-renal aortic aneurysm cases has been higher than that of infrarenal aortic aneurysm cases, especially in high-risk patients. A manufacture-modified fenestrated Zenith stent graft system has already been developed, however this new device is not yet available in Japan. Furthermore this device could not be used in an emergency situation because it takes 2-3 weeks for preparation. Therefore we introduced a surgeon-modified fenestrated Zenith stent graft (fenestrated Zenith) system in December 2010 for patients with a proximal neck length of 5-10 mm. The fenestrated Zenith was not indicated if the supra-renal angle and proximal neck angle exceeded 35°. From May 2007 to February 2012, abdominal aortic aneurysms (AAA) with a short neck were repaired with fenestrated Zenith in 11 high-risk patients (group Fene), and AAAs with a proximal neck length of more than 15 mm were repaired with a standard Zenith in 43 patients (group IFU). There were two ruptured AAA in the Fene group. Proximal neck length was significantly shorter in the Fene group (5.5±1.4 mm in the Fene group, 26.4±9.5 mm in the IFU group, <i>p</i><0.0001) and proximal neck angle was significantly less in the Fene group (20±13° in the Fene group, 36±18° in the IFU group, <i>p</i>=0.008). The Zenith stentgraft system was deployed successfully in all patients. The frequency of type Ia endoleak detected by angiography after stent graft deployment and balloon attachment did not differ significantly (36% in the Fene group 26% in the IFU group, <i>p</i>=0.475) and the frequency of Palmaz stent requirement for type Ia endoleak which persisted after 10 min of additional balloon attachment also did not differ significantly (27% in Fene group, 9% in IFU group). All fenestrated renal arteries were shown to be patent by angiography. There was no hospital death despite 2 cases of ruptured AAA, nor were these major complications in either group. Serum creatinine levels at 1, 3, 6 and 30 days after EVAR did not differ significantly between the 2 groups. In 9 out of 11 patients, only type II endoleaks were detected and aneurysm shrinkage tended to be more in Fene group (9.9±5.7 mm in Fene group, 5.4±6.1 mm in IFU group, <i>p</i>=0.062) on enhanced CT 6 months after EVAR. Also all fenestrated renal arteries were patent in these 9 patients. The surgeon-modified fenestrated Zenith system seemed to be effective for AAA patients with short proximal necks, but long term follow up is mandatory.