Frozen Elephant Trunk Procedure
Endovascular stent grafting through a median sternotomy for a distal arch aneurysm (the frozen elephant trunk procedure) is an alternative to synthetic graft replacement.
The frozen elephant trunk procedure is basically the 1st stage of the elephant trunk procedure, but instead of the distal end of the graft being left to float free in the descending aorta, a stent is used so that it is anchored to the descending aortic wall. This eliminates the need for the 2nd stage of the elephant trunk procedure.
Patient too high risk for classic two stage elephant trunk procedure.
Poor stent landing site.
The endovascular covered stent grafting (EVG) was made with a double-linked 10-bend Z stent (50-mm length and 20% larger than the diameter of the descending aorta), and an ultra-thin woven Dacron graft (10% larger than the diameter of the descending aorta; Ubekosan, Ube, Japan). The graft and Z stent were sutured together at each bend. The Z stent alone was installed in a 12F delivery sheath (Greenfield Vena Cava Filter; Boston Science Corp., Boston, MA) with an extra-hard guidewire (Amplatz Superstiff Guidewire; Boston Science Corp.). A pigtail catheter was inserted through the groin artery into the distal aortic arch. Both the axillary arteries were exposed and anastomosed with 10-mm diameter synthetic grafts as outflow cannulation. A median sternotomy was carried out, and cardiopulmonary bypass was initiated with two-staged right atrial drainage, and both the axillary arterial perfusion and core cooling were utilized. The heart was arrested with antegrade cardioplegia with the aorta clamped. A 10-mm diameter synthetic graft was anastomosed to the aortic root. At a nasopharyngeal temperature of 20°C, low-flow perfusion (10 mL/min/kg) of both axillary arteries was initiated with clamping of the brachiocephalic artery and with ligation of the left subclavian artery. The left subclavian artery was principally reconstructed.
The anterior wall of the aortic arch was incised and the distal aortic arch was exposed. An EVG was inserted by aortotomy into the descending aorta under the pigtail catheter and guidewire guidance. The Z stent was deployed just below the aneurysm. The distal edge of the Z stent was placed more than 6 cm below the aneurysm edge in order to ensure an adequate landing zone, under monitoring with transesophageal echocardiography. The graft was fixed to the aortic wall with at least two anchoring sutures of 3-0 polypropylene placed through the aortotomy. The proximal site of the graft was trimmed according to the proximal suture line surrounding the orifice of the left common carotid artery. Proximal anastomosis to the posterior wall was performed surrounding the orifice of the left common carotid artery using the inclusion technique with 3-0 polypropylene, and the aortotomy was then closed, fixing the anterior wall of the EVG. Full-flow perfusion was resumed after unclamping of the brachiocephalic artery. The graft to the left subclavian artery was anastomosed to an aortic root graft.
Both the axillary arteries were anastomosed with 10-mm-diameter synthetic grafts as outflow cannulation. The anterior wall of the aortic arch was incised, an EVG was inserted through an aortotomy, and the Z stent was deployed just below the aneurysm. The graft was fixed to the aortic wall with at least two anchoring sutures. Proximal anastomosis to the posterior wall was performed surrounding the orifice of the left common carotid artery using the inclusion technique, and the aortotomy was then closed, fixing the anterior wall of the EVG. The left subclavian artery was principally reconstructed.
Axial computed tomographic sections of patient with aneurysms of ascending aorta .
(a) as well as of proximal descending aorta commencing at origin of left subclavian artery
(b). After open surgical replacement of ascending aorta
(c) and placement of stent graft in aortic arch and descending aorta
(c), note that aneurysm of descending aorta has thrombosed completely around stent graft (d).
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Spinal cord dysfunction rate is relatively high after this procedure.
Routine, but with regular CT or MRI scans