An Innovative Research Of Endovascular Repair For Type B Aortic Dissection Using Two Covered-stent Grafts

ObjectiveTo investigate the effect of treatment of type B aortic dissection using two covered-stent grafts.MethodsClinical,imaging and postoperative follow-up data of 61 cases with Stanford type B aortic dissection treated by TEVAR using two covered-stent grafts from March2013 to 2015 march in our center were analyzed.The indications of endovascular repair:(1)the bending deformation of thoracic-descending aorta(2)thoracic-descending aorta existing multiple ruptures(3)collapse of true lumen by oppressing of false lumen at the distal end of stent.The operation procedure:(1)according to the condition and diameter of the proximal landing zone and the location of the distal landing zone to select the first covered stent graft(2)according to the diameter and condition of the distal landing zone to select the second coated stent graft(independent research and development of large taper coated stent, length119 mm,taper 10),two covered-stent grafts were orderly implanted and partially overlapped. Long diameter(D)、area(S) of the true lumen at distal segment of stent and the Length of covered stents(L) were measured. The oversize ratio(OR) based on diameter, area were calculated respectively. Thoracoabdominal aortic CTA were examined at postoperative 7day, 3 month, 6 month,1year and thereafter every year.The effect of endovascular repair, condition of false lumen thrombosis,distal stent graft-induced new entry and other related complications were studied.ResultsA total of 61 cases using two covered-stent grafts to treat Stanford type B aortic dissection, proximal extended chimney were used in 4 cases(6.6%), partial coverage of the left subclavian artery in 11 cases(18.0%), application of Gore Viabahn torescue unilateral renal artery completely originated from false lumen in 2 cases(3.3%). A total of 5 different types of stent combination,Valiant+Grikin two covered-stent graft are 40 cases(65.6%),Zenith+Grikin are 10 cases(16.4%),Grikin+Grikin are 8 cases(13.1%),Hercules+Grikin are 2 cases(3.3%),TAG+Grikin are 1 cases(1.6%).The mean followed up was 23.6±7.4 months(range 12-35 months).The mean length of the stent graft was 213.9±27.4mm and the oversize ratio of diameter and area at the distal of stent were 8.8±4.9% and 46.8±18.4%, respectively.1 case(1.6%)died during perioperative period, the distal stent graft-induced new entry in 1 case(1.6%), distal stent malapposition in 3 cases(4.9%),right femoral artery thrombosis occurred in 1 case(1.6%).Complete thrombosis of the segment of stent was 91.8%(55/61),including complete disappear of false lumen of the segment of stent was 41.8%(23 /55) and complete aortic remodeling rate was 7.3%(4/55).No stroke or paraplegia occurred.ConclusionThe precise selection of the distal landing zone in the treatment of Stanford B aortic dissection was improved by two covered-stent grafts, which can achieve a safe and satisfied effect in early and medium-term,but the medium and long term follow-up outcome was still required.