18.9% of patients undergoing EVAR develop type-II endoleak, mostly due to patent inferior mesenteric or lumbar arteries. Among those with endoleak, 79.9% experience complete and permanent resolution in ≤ 6 months, while 20.1% have persistent endoleaks [1
]. Leaks that occur along the ventral aspect of the aneurysm sac are usually caused by retrograde flow from a patent IMA, while those that occur along the dorsal aspect of the sac are usually caused by a patent lumbar artery [2
]. It has been shown with use of microcatheters that the pressure within the sac related to a type-II endoleak is at or near peak systole. Tolia et al reported that a persistent type-II endoleak is associated with an increased incidence of aneurysm sac growth, reintervention rate, the need for conversion to open repair, and the risk of sac rupture [3
]. Therefore a more aggressive approach to management of persistent type-II endoleak has been advocated by many authors [4
]. Lack of patient compliance with close follow-up as well as the potential negative renal effects of repeated intravenous contrast CT scan surveillance also favors early intervention.
Although a significant number of patients experience IMA endoleak, the majority of the cases ultimately result in spontaneous resolution yielding a small role for routine preoperative embolization [6
]. Characteristics of the flow seen on color Doppler studies are often used to predict outcomes. Rapid flow represents a bad prognosis, whereas low velocity with a to-and-fro movement of blood predicts spontaneous thrombosis and endoleak resolution [7
]. The other prognostic factor influencing the outcomes and clinical significance of type-II endoleaks is the size of the nidus of flowing blood. If the diameter of the nidus exceeds 1.5 cm, aneurysm enlargement will most likely occur [8
To our knowledge, there has been no consensus on how to best treat type-II endoleaks. When reperfusion of the aneurismal sac via the SMA occurs through the IMA, the IMA origin can be accessed and coil embolization performed via the marginal artery of Drummond or the arch of Riolan. This transarterial technique is safe and highly effective with up to 100% success rate at 2-year follow-up [4
]. In the translumbar approach, the aorta is punctured under CT or fluoroscopic guidance. Left sided access is typically used to avoid the inferior vena cava. The access needle is angled at about 45-60 degree antero-medially, aimed so as to pass just anterior to the vertebral body, avoiding the adjacent transverse process. Once in the sac, proper arteriography is performed followed by coil embolization. Compared to the translumbar approach, the transarterial technique avoids substantial complications related to access-tract soft tissue infection and retroperitoneal hematoma.
Among the many choices regarding embolic agents, permanent material such as coils is preferred. Some authors support use of either gelfoam slurry or thrombin in addition to coils. Baum et al pointed out that secondary recanalization can occur after these procedures. Therefore, to obtain an effective and durable result, dense packing of microcoils seems to be necessary [9
]. The use of other agents, including Vinyl alcohol copolymer, Ethibloc, and Cyano-acrylate has also been successfully reported [10
Laparoscopic or open surgical ligation of all relevant branches is a possible solution for the type-2 endoleaks. However experience has shown that there are often more vessels involved in these lesions than is initially suspected, and unless they are all clipped, the surgical route invariably results in failure or recurrence. The commonly encountered dense adhesion and fibrotic tissues around the aneurysmal sac also lower the chance of success with the operative methods [14