EVAR: Critical applied aortic morphology relevant to type-II endoleaks following device enhancement in patients with abdominal aortic aneurysms

Endovascular repair (EVAR) of abdominal aortic aneurysms (AAA) is an established alternative option to conventional surgery for AAA, provided optimal anatomical morphology of the aneurysm sac, neck and outflow exists. In most documented series of EVAR, type-II endoleak occurrence is a universal procedural drawback. This is referred to as the Achilles heel of EVAR. This morphological study, addressing predominantly non-aneurysmal aortic anatomy, reveals the dyssynchronous origins of the renal ostia, ectopia of the superior mesenteric artery and median sacral artery, variations in the length of the infrarenal abdominal aorta, multiple mainstem renal arteries, and the presence of accessory renal arteries (in 13% of cadavers). Such potential vascular anomalies need careful consideration pre-operatively prior to EVAR. In a prospective, clinical study of EVAR in 163 patients over 60 months, using four different aortic stent devices, we demonstrated an intraprocedural type-II endoleak rate, before exclusion, of 3% (5/163). Most were related to patent lumbar arteries. An active policy of intraprocedural aneurysm pressure sac measurement and angiography was used to demonstrate type-I and type-II endoleaks, focusing on the applied anatomy of aortic side branches and variations. Selective intraprocedural coli embolisation and thrombin injection into the sac was utilised to thrombose persisting and large lumbar arteries that predisposed to retroleaks. We recorded a low incidence of persisting type-II endoleaks using this proactive treatment strategy by addressing variant aortic morphology and patent lumbar arteries during EVAR. One aneurysm-related death (0.6%) was observed due to late rupture after EVAR, and a single intraprocedural death was related to unpredictable aneurysm rupture. In conclusion, comprehensive anatomical knowledge of the abdominal aorta and its main collateral side branches, including variations, is a fundamental prerequisite if satisfactory and predictable results are to be achieved after EVAR, especially regarding prevention, diagnosis and treatment of type-II endoleaks. Intraprocedaral aneurysm sac pressure monitoring, coil embolisation and the use of injection of thrombin into the aneurysm sac of selected patients is useful in reducing the incidence of post-EVAR type-II persisting endoleaks.Conference Pape

Carotid stenosis and carotid plaque analysis relevant to carotid endarterectomy and stent-assisted angioplasty

The primary objective of this cadaveric study was to review the morphological variations of the anatomy of the human carotid artery bifurcation relevant to carotid endarterectomy (CEA) and carotid artery stent-supported angioplasty (CSSA). We quantify carotid bifurcation plaque morphology. Results showed that the angle of deviation at the origin of the internal carotid artery (ICA), in relation to the common carotid artery (CCA), measured a mean of 21.8 degrees with a range from seven to 45 degrees. This anatomical finding is important for the interventionalist concerned with insertion of a carotid stent. The angle of the ICA origin may be an independent risk factor for early atherosclerotic changes at the ICA bulb. Carotid bifurcation plaque was observed in a small, random cohort of seven out of 13 cadavers, and contributed to a mean stenosis of 15.2% (range 5.0-34.8%). Plaque morphology (n = 7) showed haemorrhage (29%), superficial thrombosis (57%), calcification (71%), areas of focal necrosis (71%), neovascularisation (14%) and infiltrates (29%). Ulcerations were not detected. Although four out of 13 patients (31%) died of a cerebrovascular accident, the cause of cerebral apoplexy was thought not to be associated with the carotid bifurcation pathology. 'Re-boring' of occluding plaque, as in CEA, offers potential volumetric anatomical advantage over CSSA within the carotid bifurcation and bulb. In conclusion, precise and applied knowledge of carotid bifurcation anatomy is critical to reduce technical complications during CEA or CSSA. This information may reduce potential dangers of iatrogenic thrombo-embolism and ensuing neurologic deficits. Patients with low-grade carotid stenosis, evidence of focal plaque necrosis, are at risk of spontaneous plaque cap rupture, distal thrombo-embolism and stroke.Revie