Spontaneous Echocardiographic Contrast Indicating Successful Endoleak Management

Abstract

A 75-yr-old woman was admitted with an enlarging descending thoracic aortic aneurysm (TAA). The patient had undergone open repair 12 yr before this admission. Tomographic scanning revealed a 9.9 9.6 cm proximal TAA with dilation of the ascending aorta and thrombus within the aneurysm. It extended from the proximal descending aorta at the level of the pulmonary bifurcation to the distal descending thoracic aorta. Given her risk profile, she was scheduled for endovascular repair. A transesophageal echo (TEE) examination performed after induction of anesthesia confirmed the preoperative findings along with mild aortic insufficiency. A “TAG” thoracic endoprosthesis (WL Gore, Newark, DE) was deployed with the distal end within the previous graft. A second TAG endoprosthesis was deployed proximal to the first, covering the left subclavian artery. Subsequently, both TEE and cine-angiography revealed a large Type IA endoleak (Table 1). The TEE images showed spontaneous echocardiographic contrast (SEC or “smoke”) within the aneurysm, indicating entry of blood into the aneurysm sac (Fig. 1; please see video clip available at www.anesthesia-analgesia.org). Color flow Doppler (CFD) imaging with a reduced velocity scale confirmed these findings (online video clip) and failed to show evidence of patent collateral vessels. A third TAG endoprothesis was then deployed 15 mm proximal to the second device and secured to the aortic walls with a trilobed endoaortic balloon. Subsequently, no further movement of the smoke, which had now acquired echodensity similar or brighter than surrounding tissue, was observed (Fig. 2, and online video clip). Initially, the origin of the flow within the sac could not be determined. However, using different imaging planes, the inflow channel was identified in the proximal stent region. This was confirmed with CFD (online video clip) and angiography. Retrograde flow from a collateral artery (type II endoleak) was considered unlikely, since flow initially was brisk, no flow in the collateral branches could be detected, and flow ceased with further endograft deployment. The primary decision regarding endoleakage and deployment of additional stents was based on angiography, with TEE providing supporting evidence. Her postoperative course was complicated by delayed onset paraparesis. She was discharged on the 16th postoperative day with some improvement. The goal of an endovascular aortic repair is to deploy a graft that seals tightly above and below the aneurysm, excluding the aneurysmal sac from systemic bloodflow to decrease risk of rupture. Although general or regional anesthesia have been used successfully, if TEE is to be used, general anesthesia is required. Small clinical studies have suggested that TEE is more sensitive and specific than angiography in detecting endoleaks (2,3). The disadvantage of angiography is that it relies on a fixed volume of contrast to circulate within the endoleak. Small leaks may be This article has supplementary material on the Web site: www.anesthesia-analgesia.org.