Endoleak embolization

The advance of endovascular therapy for aorto-iliac aneurysmal disease has also brought about yet another flourishing application of embolotherapy. Embolization of the internal iliac artery plays an important adjunct initial modality to allow endovascular treatment of aortic aneurysms with extension into the common iliac arteries [78-80], It also plays an crucial role in the secondary management of complications related to endoleaks [81-84],... 

Baum RA, Cope C, Fairman RM, Carpenter JP (2001) Translumbar embolization of type 2 endoleaks after endovascular repair of abdominal aortic aneurysms. J Vase Intervent Radiol 12 111-116... 

Endoleaks Spiral CT, MRI, angiography, duplex US Recurrence/non-target embolization... 

Embolization of the sac or the channel, although feasible, is usually not indicated in type I-B endoleak. 

The occlusion of the iliac artery is usually sufficient to treat the leak. However, in cases of long-term type IC endoleak, many outflow vessels may have developed and the leak may communicate with multiple lumbar arteries and the IMA. These enlarged vessels might be source of late type II endoleak. Thus, we usually embolize both the outflow vessels and the sac before occluding the iliac artery. Another attractive technique to achieve the occlusion of the common iliac artery is to perform an endovascular internal to external iliac artery bypass using stentgraft. This technique can allow the exclusion of the common iliac preserving the internal iliac artery. 

Regardless of the route chosen, the most important task is to access the channel or the sac. It is critical to disrupt the network between the involved vessels. This is more important than occluding any one vessel or even embolizing the endoleak sac (Figs. 14.3, 14.4). This explains the high rate of recurrence after IMA embolization alone (Fig. 14.4) compared to translumbar embolization for type II endoleak in one report [44]. 

There are multiple reports of the use of thrombin in the percutaneous, translumbar embolization of type II leaks. Most authors report the use of 500-1500 units of thrombin [49]. The only reported serious complication occurred in a case where 8000 units were injected [50]. The complication was ischemic colitis in the recto-sigmoid region the IMA was patent in this case. Despite the complication, the procedure was successful in sealing the endoleak. 

Schmid R, Gurke L, Aschwanden M, et al (2002) CT-guided percutaneous embolization of a lumbar artery maintaining a Type II endoleak. J Endovasc Ther 9 198-202... 

As mentioned above, status of the internal iliac arteries is an important anatomic consideration in the treatment of aortoiliac aneurysms. Indications for embolization of IIA in association with EVAR include aneurysm of the IIA or ectatic or aneurysmal common iliac artery (CIA) involving the origin of IIA. Additionally, extension of stent-graft into the external iliac artery (El A) may become necessary if the CIA is judged to be too short for adequate or safe anchoring of the device or if there is a distal type-I endoleak. This will lead to loss of antegrade flow in the IIA. 

Occasionally, communications between branches of an uninvolved IIA and distal lumbar arteries can create type-II endoleaks (Fig. 15.1). This can be a more technically challenging situation and embolization of the distal branches should be attempted only if growth of the aneurysm sac has been documented (see Sect. 15.2.1). 

Fig. 15.1. a Contrast. enhanced CT of abdomen shows an abdominal aortic aneurysm with patent lumbar and inferior mesenteric arteries. Patient developed a type 11 endoleak after endograft placement, b Non-contrast CT shows glue embolization of the lumbar arteries and the sac through a branch of the internal iliac artery... 

Occasionally, communications between various branches of the IIA and the lumbar arteries may cause retrograde flow into the sac of an aortic aneurysm creating a type-II endoleak. Microcatheter traversal of the entire length of these conununications may not always be possible. Under such circumstances, liquid embolic agents have been employed to occlude the feeder arteries. As mentioned above, this practice may cause ischemic radiculopathy if the targeted vessels are either lateral sacral or iliolumbar arteries. It may be more prudent to coil embo-lize these arteries and use alternative approaches to deal with the possible residual type-II endoleak (see Chap. 14). 

Heye S, Nevelsteen A, Maleux G (2005) Internal iliac artery coil embolization in the prevention of potential type-2 endoleak after endovascular repair of abdominal aortic... 

Additional clinical applications in the body that can benefit from C-arm CT are drainages and punctures. When performing percutaneous biliary drainage procedures, Froehlich et al. (2000), for example, found that C-arm CT resulted in decreased procedure and fluoroscopy times. C-arm CT can also be beneficial for complicated transjugular intrahepatic portosystemic shunt cases (SzE et al. 2006). Binkert et al. (2006) described another successful application for C-arm devices providing both 2D and 3D imaging. They used the 3D cross-sectional information for needle placement and 2D fluoroscopy to perform embolization of translum-bar type II endoleaks. 

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