Endovascular Management of Isolated Iliac Artery Aneurysms



Endovascular Management of Isolated Iliac Artery Aneurysms



Margaret W. Arnold, Peter L. Faries and Michael L. Marin


The traditional repair of isolated iliac artery aneurysms (IAAs) has been through an open surgical approach. The pelvic location of the isolated iliac aneurysm can increase the technical difficulty of open repair. The operative mortality for open elective repair of isolated iliac aneurysms has been reported as high as 10%, which is greater than the operative mortality associated with open abdominal aortic aneurysm repair. However, because of this, and with the continued success and advancements in endovascular aortic aneurysm repair (EVAR), endovascular repair of IAAs gained in popularity and in the majority of major vascular centers is the treatment of choice.



Preoperative Planning and Imaging


The endovascular management of IAAs requires meticulous preoperative imaging and planning. In general, this consists of a computed tomography angiogram (CTA) with fine cuts (2 mm). Multiplanar three-dimensional reconstructions can be used to delineate complex anatomy (Figure 1). This can be especially important in treating internal iliac artery aneurysms, which can have multiple outflow vessels that can require embolization. In addition, diagnostic angiography may be performed to obtain accurate measurements for graft sizing (Figure 2). Angiograms done with calibrated catheters can be very useful in determining the correct length of the device, especially in tortuous vessels.


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FIGURE 1 Reformatting software can be used to construct a center line to help determine optimal graft sizing and length.

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FIGURE 2 Diagnostic angiogram showing isolated iliac artery aneurysm.

One of the first reported methods for the endovascular repair of IAAs was with a handmade graft of polytetrafluoroethylene (PTFE) sewn to a balloon-expandable stent. As the field of endovascular surgery has advanced, so have the grafts available to repair IAAs. Today, several stent grafts are available for endovascular repair of these aneurysms. These most often consist of a metal stent composed of nitinol or of stainless steel wrapped in a fabric coating—Dacron or PTFE. The devices come in various lengths and diameters, and tapering options are available as well. Tapered devices can even be backloaded onto the delivery system to allow a reverse taper. Each device is different in terms of its flexibility and size profiles. Dedicated iliac devices are not available because of the relatively low incidence of these aneurysms.



Operative Technique


The general principles of repair of IAAs are similar to the endovascular repair of abdominal aortic aneurysms. The objective is to isolate the aneurysm from arterial perfusion pressure and prevent rupture while maintaining perfusion to the lower extremity. An adequate seal zone of at least 15 mm proximal and distal to the aneurysm allows adequate fixation and achievement of a hemostatic seal to isolate the aneurysm from the arterial circulation and prevent rupture. If an adequate proximal and distal seal zone is present, then a stent graft can be deployed across the isolated IAA. Traditionally, this is done through a femoral artery cutdown and transfemoral deployment of the stent graft. As the profile of the delivery systems has decreased, a percutaneous approach for delivery and deployment has become feasible. If percutaneous deployment is being considered, the femoral artery must be carefully evaluated to ensure that the artery will not be damaged by the sheath insertion and that the arteriotomy is amenable to repair with a closure device. Anterior calcification of the access vessels as well as access vessel stenosis have been cited as predictors of failure of the percutaneous approach.


Often, adequate proximal and distal seal zones are not present, and adjunctive measures must be taken to repair the isolated IAA. For aneurysms involving the origin of the internal iliac artery, or for aneurysms without adequate length (15 mm) of normal vessel before the takeoff of the internal iliac artery, the origin of the internal iliac artery is embolized with coils or an endovascular plug (Figure 3). Embolization is performed to prevent perfusion of the iliac aneurysm from retrograde flow in the internal iliac artery once the stent graft has been deployed across its origin (type II endoleak). The stent graft is then placed across the origin, and the seal zone is created within the external iliac artery.


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FIGURE 3 Placement of an endovascular plug at the origin of the internal iliac artery for embolization.

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  2. In-Situ Treatment of Aortic Graft Infection with Prosthetic Grafts and Allografts
  3. Treatment of Acute Upper Extremity Venous Occlusion
  4. Intraoperative Assessment of the Technical Adequacy of Carotid Endarterectomy

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Aug 25, 2016 | Posted by in CARDIOLOGY | Comments Off on Endovascular Management of Isolated Iliac Artery Aneurysms

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