1. Zenith AAA Endovascular Graft for Abdominal Aortic Aneurysm
Department of Radiology, Nara Medical University
Kimihiko Kichikawa, Shoji Sakaguchi, Wataru Higashiura, Kiyoshi Nishimine, Masayoshi Inoue
Department of Radiology and IVR Center, Daiyukai General Hospital
Takeshi Nagata, Hideo Uchida
We here describe the evolution of the Zenith AAA endovascular graft (Zenith AAA) for treatment of AAA. Since its first use in 1993, Zenith AAA underwent several improvements towards the current model, which has been used in more than 15,000 cases world-wide. Zenith AAA is a 3-piece modular system including a bifurcated aortic body and 2 iliac leg extensions.The device incorporates self-expanding stainless-steel Z-stents attached to a polyester graftmaterial. The bodies come in diameters from 22～ 32mm, and in 5 different lengths, which can be delivered through introducers of 18 or 20 Fr. The iliac leg extensions come in a wide range of lengths and diameters. Zenith AAA has transrenal fixation with a bare stent including barbs and hooks, and the best resistance to dislodgment, compared to other stent-grafts. A number of reports have been published on the Zenith AAA. In an analysis of results from 3 US clinical trials, reduction in sac size was greatest with Zenith, and the incidence of any endoleak lowest. Follow-up results of a prospective clinical trial in Japan showed the safety and effectiveness of Zenith AAA, which seems to be suitable for AAA in Japan. Finally the Zenith AAA acted as the platform in the development of fenestrated and branched grafts.
● Abdominal aortic aneurysm
● Stent graft
● Zenith AAA
2. Endovascular Stent-Grafting for Thoracic Aortic Aneurysms
Department of Vascular Surgery1), Center for Minimally Invasive Treatment of Cardiovascular Diseases2) Tokyo Medical University
Satoshi Kawaguchi1,2), Hiroshi Shigematsu1)
Despite advances in operative technique and management having improved the clinical outcomes of conventional open surgical replacement for thoracic aortic aneurysms, it remains an invasive procedure especially for patients require emergency treatment. Over the past fifteen years, minimally invasive endovascular surgery using a stent graft has made significant advances in the treatment of aneur ysms. For twelve years from 1995, 627 patients with thoracic aortic aneurysms including 193 aortic dissections were treated with the endovascular technique using the SG in our hospital. We used an individually designed stent graft for each patient and for distal arch aneurysms. SG should be designed so that it has a scallop or fenestration on the graft to keep blood flow into the arch vessels. Exclusion of the aneurysms or closure of entry without endoleak were achieved within two weeks postoperatively in over 94%. Endovascular stent grafting shows potential as a safe and useful treatment for thoracic aortic diseases, but further investigation should attempt to determine its efficacy over a longer postoperative period.
● Stent graft
● Thoracic aortic aneurysms
3. Characteristics of the MK Stent Graft System for Endovascular Aortic Repair
Department of Radiology, Kanazawa University Hospital
Junichiro Sanada, Osamu Matsui
The MK stent-graft is constructed from a self-expanding stent comprised of a braided single nitinol wire and a seamless, cylindrical woven graft made of polyester fabric. That braided structure makes it flexible and more suitable for tortuous aortic segments. However, the MK stent-graft may not conform to the cranked aortic segment or the aortic segment with drastic changes of the aortic caliber. These drawbacks may cause endoleaks, so that the proximal and distal landing zones should be covered sufficiently in such situations. The braided structure has another advantage that allocates the radial force of the stent-graft to the whole inner surface of the stent-grafted segment, because it has a wider surface area that comes in contact with the aortic inner wall. The MK stent-graft has other unique properties of superelasticity and shape memory. These characteristics allow for complex configurations and deployment through smaller profile delivery systems, so that it can be widely applied in many kinds of cases, such as a case with unsuitable anatomical configurations for commercial stent-grafts or acute aortic rupture. A better understanding of the properties of the MK stent-graft would enhance the clinical usefulness of this unique system.
● Matsui-Kitamura stent-graft
● MK stent-graft
● Thoracic aortic aneurysm
● Endovascular aortic repair
4. Inoue Stent Graft in Patients with Aorto-iliac Diseases Unfit for Open Surgical Repair
Dpartment of Diagnostic Radiology and Surgery1), Keio University School of Medicine
Subaru Hashimoto, Sachio Kuribayashi, Makiko Shinohara, Seishi Nakatsuka, Kazuhiro Matsumoto
Masanori Inoue, Hideyuki Shimizu1), Ryohei Yozu1), Hideaki Obara1), Kenji Matsumoto1)
Department of Cardiovascular Surgery, Shimabara Hospital
Thirty-two patients with growing aorto-iliac true aneurysm, pseudo-aneurysm or PAU were treated using Inoue stentgraft (ISG). All the patients were judged unfit for open surgical repair because of previous surger y, poor cardio-pulmonar y function or other co-existing morbidities. Materials included patients with poor anatomical conditions such as proximal landing zone (PLZ) 10 mm in length or PLZ with 90-degree angulation. A branched-ISG was used in patients with distal arch aneurysm, a Y-ISG for abdominal aortic aneurysm and a straight-ISG for descending thoracic aortic diseases, extra-anatomical bypass graft tear and for isolated iliac aneur ysm. Successful introduction and deployment of the device in the absence of surgical conversion or mortality, type I or III endoleaks or graft limb obstruction were achieved in all cases. There was a device-unrelated aneurysmal rupture and death in a patient with descending thoracic aneurysm sixteen months following the procedure. There were no type I or III endoleaks throughout the entire follow-up period. ISG placement in highrisk patients unfit for open surgical repair for aorto-iliac diseases is considered to be safe and highly effective. This method is the treatment of choice even in patients with poor anatomical conditions as well as those with surgical risks.
● Inoue stentgraft
● Endovascular aneurysmal repair
● Surgically high risk patients