Type A Dissection Repair With Fenestrated Frozen Elephant Trunk

2019-04-08T19:08:07Z (GMT) by Kyle W. Eudailey
<p><strong>Background</strong></p><p>Standard of care for acute type A dissection remains the “hemiarch” technique with an open distal anastomosis. This operation is currently favored because of its simplicity and reproducibility, as it is believed to carry a lower operative risk than more aggressive treatment of arch pathology. Data for this claim remains limited, and there remains a significant portion of patients who survive their initial hemiarch operation but who are left with complex aortic pathology which may require high-risk future intervention.</p> <p>The question remains whether more aggressive treatment of aortic pathology up front at the time of a type A dissection is better both in the early phase as well as long term. Here, the author presents a video of a simplistic technique for a fenestrated frozen elephant trunk (FET), which allows for more aggressive treatment of the aortic arch at the time of type A dissection, as well as stabilization of the true lumen. The author believes this results in improved aortic remodeling, which should result in improved long-term results with no change in early mortality or complications. This technique was originally described by Roselli and colleagues [1]. It is a simple and effective way to treat more arch pathology up front with limited circulatory arrest time.</p><p><strong>Operative Steps</strong><br><br><em>Preoperative Evaluation and Planning</em></p><ul><li>Confirm normal arch anatomy, with particular attention to the origin of the vertebral artery.</li><li>Preoperative measurements of the transverse and descending aorta, to confirm the size of frozen elephant trunk. Size one-to-one at most, never longer than a 100 mm stent.</li><li>Preoperative measurements of the left subclavian artery, as well as the distance to the take-off of the left vertebral artery.</li><li>Intraoperative transesophageal echocardiographic (TEE) evaluation of the aortic root and the extent of root pathology.</li></ul><p><br><em>Cannulation and Bypass Setup</em></p><ul><li>Central cannulation is done using the Seldinger technique. True lumen cannulation is confirmed by TEE visualization of the descending aorta.</li><li>Cooling to 28 degrees, as monitored by rectal and bladder temperatures.</li><li>Retrograde and direct ostial del Nido cardioplegia are given.</li><li>A 16F DLP vent placed in the right superior pulmonary vein.</li><li>Circulatory arrest in steep Trendelenburg position.</li><li>Direct cannulation of the true lumen of the innominate and left carotid arteries with flexible 16F retrograde cardioplegia cannulas, thus initiating selective antegrade cerebral perfusion at 8 -10 cc/kg/min with continuous cerebral oximetry monitoring.</li></ul><p><br><em>Operation</em></p><ul><li>Following circulatory arrest, evaluate the aortic root pathology.</li><li>Next, turn attention back to the arch and resect the aorta to the level of the innominate artery.</li><li>Look specifically for large tears and ensure that the innominate and left carotid arteries do not have large tears at ostium. If they do, this may warrant a proper debranching of head vessels.</li><li>Feed a single curve lunderquist wire into the true lumen of the descending aorta.</li><li>Advance the stent into the thoracic aorta.</li><li>Deploy the stent, favoring a slightly deep deployment.</li><li>Use eye cautery to fenestrate the FET at the level of the left subclavian artery.</li><li>Advance the left subclavian stent over a soft J-wire to the desired depth (based on preoperative measurements) and deploy it.</li><li>Use a right-angle clamp to ensure the patency of the left subclavian stent. Confirm back-bleeding.</li><li>Optional placement of several tacking horizontal mattress sutures on the superior third of the FET.</li><li>Trim the collar of the hemiarch graft, and complete a standard hemiarch anastomosis being sure to include the inferior third of the stent graft in the anastomosis. Try to avoid placing stitches through stent struts.</li><li>De-air the graft, clamp proximally, and resume full bypass flow and rewarming down the side-arm of the graft.</li><li>Complete the proximal root operation as needed.</li><li>De-air, reperfuse, wean from bypass, and complete hemostasis in the standard fashion.</li></ul><p><br><em>Grafts Used</em></p><ul><li>FET: Medtronic (Dublin, Ireland) Valiant Thoracic Stent Graft</li><li>Left Subclavian Stent: Gore (Newark, Delaware, USA) Viabahn</li><li>Ascending Graft: Terumo (Tokyo, Japan) Sienna Gelweave Single Arm</li></ul><div><p><strong>References</strong></p><ol><li>Roselli E, Idrees J, Bakaeen F, et al. Evolution of simplified frozen elephant trunk repair for acute Debakey type I dissection: midterm outcomes. <a href="https://doi.org/10.1016/j.athoracsur.2017.08.037"><em>Ann Thorac Surg</em>. 2018;105(3):749-755.</a></li></ol><div>Dr Eudailey is a consultant for Medtronic and Terumo.<br></div></div><p></p>