A study of aortic dimension in type B aortic dissection.
ABSTRACT Difference between arch diameter and true lumen diameter in the descending aorta was studied in patients with type B aortic dissection. The diameters of the aortic arch (Proximal ) and mid-descending aorta (Distal ) were measured on computer tomography angiography (CTA) in 20 healthy adults. Forty-two patients with type B aortic dissection who underwent endovascular repair were divided into two groups: an acute group (23 patients) and a chronic group (19 patients). The diameters of the arch (Proximal ) and the true lumen of the mid-descending aorta (Distal ) were measured on digital subtraction angiography (DSA) and CTA. The taper ratio was defined as (Proximal -Distal )/(Proximal )x100%. In the control group, the taper ratio was 13.0+/-4.7% on CTA. In the acute patients group, the taper ratio was 23.6+/-11.3% on DSA and 21.9+/-12.1% on CTA. In the chronic patients group, the taper ratio was 31.5+/-13.6% on DSA and 30.1+/-11.4% on CTA. In both acute and chronic type B aortic dissection, the aorta tapers significantly from arch to true lumen in the descending aorta. Stent-graft with tapered design may be a viable treatment option for endovascular repair of type B aortic dissection.
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ABSTRACT: Purpose : To describe the use of protective stents in the endovascular repair of acute complicated Stanford type B aortic dissections. Methods : From 2009 to 2011, 33 patients (27 men; mean age 47 years, range 31-73) with acute complicated Stanford type B aortic dissection underwent thoracic endovascular aortic repair (TEVAR) assisted by protective stents. In all cases, the proximal and distal landing zones differed in size by >5 mm, and the primary entry tear was in the proximal descending aorta. A bare self-expanding stent (protective stent) was deployed initially at the intended distal landing site of the primary stent-graft in the true lumen. The intention was that the bare stent would prevent excessive dilation of the distal end of the stent-graft in the vicinity of the entry tear, thus avoiding intimal rupture. Results : Successful stent deployment and sealing of the entry tear was achieved in all patients. The median diameter and length of the protective bare stents was 20.3 mm (range 18-24) and 72.7 mm (range 60-80), respectively, while the corresponding dimensions of the covered stent-grafts were 32.8 mm (range 26-40) and 157.4 mm (range 120-200 mm), respectively. There was no stent twisting, migration, of rupture of the false or true lumen. Computed tomography 1 week postoperatively demonstrated closure of the primary entry tear with thrombosis of the false lumen in all cases. No patients were lost to follow-up, which has ranged from 3 months to 3 years. No late endoleaks or stent complications, such as angulation, dislodgment, persistent leaks, branch obstruction, or stent-graft migration, have been observed, and there has been no chronic progressive true or false lumen dilatation, recurrences, or deaths. Conclusion : Adjunctive use of a protective stent when treating acute Stanford type B aortic dissections in which the diameters of the proximal and distal landing zones differ by >5 mm is feasible and safe and provides good short-term outcomes.Journal of Endovascular Therapy 04/2013; 20(2):210-8. · 2.70 Impact Factor
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ABSTRACT: Stent graft-induced new entry (SINE), defined as the new tear caused by the stent graft and excluding those arising from natural disease progression or iatrogenic injury from the endovascular manipulation, has been increasingly observed after thoracic endovascular aortic repair (TEVAR) for Stanford type B dissection in our center. SINE appears to be remarkably life threatening. We investigated the incidence, mortality, causes, and preventions of SINE after TEVAR for Stanford type B dissection. Data for 22 patients with SINE were retrospectively collected and analyzed from 650 patients undergoing TEVAR for type B dissection from August 2000 to June 2008. An additional patient was referred to our center 14 months after TEVAR was performed in another hospital. The potential associations of SINE with Marfan syndrome, location of SINE and endograft placement, and the oversizing rate were analyzed by Fisher exact probability test or t test. We found 24 SINE tears in 23 patients, including SINE at the proximal end of the endograft in 15, at the distal end in 7, and at both ends in 1. Six patients died. SINE incidence and mortality reached 3.4% and 26.1%, respectively. Two SINE patients were diagnosed with Marfan syndrome, whereas there were only 6 Marfan patients among the 651 patients. The 16 proximal SINEs were evidenced at the greater curve of the arch and caused retrograde type A dissection. The eight distal SINEs occurred at the dissected flap, and five caused enlarging aneurysm whereas three remained stable. The endograft was placed across the distal aortic arch during the primary TEVAR in all 23 patients. The incidence of SINE was 33.33% among Marfan patients vs 3.26% among non-Marfan patients (P = .016). There was no significant difference in mortality between proximal and distal SINE (25% vs 28.6%, P > .99), incidence of SINE between endograft placement across the arch and at the straight portion of descending thoracic aorta (23 of 613 vs 0 of 38, P = .39), and the oversizing rate between SINE and non-SINE patients (13% ± 4.5% vs 16% ± 6.5%, P = .98). SINE appears not to be rare after TEVAR for type B dissection and is associated with substantial mortality. The stress yielded by the endograft seems to play a predominant role in its occurrence. It is important to take this stress-induced injury into account during both design and placement of the endograft.Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter 12/2010; 52(6):1450-7. · 3.52 Impact Factor
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ABSTRACT: OBJECTIVES: Stent graft-induced new entry (SINE) has been increasingly observed after thoracic endovascular aortic repair of aortic dissection. We illustrate the possible mechanism by exploring predictive factors of late distal SINE after hybrid arch elephant trunk repair for aortic dissection. METHODS: From November 2006, to May 2011, 20 of 99 patients underwent hybrid arch repair using the elephant trunk graft as the proximal landing zone. After a mean follow-up period of 27.9 ± 12.0 months, 12 patients had late distal SINE events and the others were free of events. False lumen remodeling level was observed and maximal longitudinal diameter, average of longitudinal and transverse maximal diameter, circumference, and area of true lumen were analyzed for precise size selection of stent graft before and after the procedure. Taper ratio, true lumen:aorta ratio, prestent grafting oversizing ratio, poststent grafting oversizing ratio, and expansion mismatch ratio of distal true lumen were proposed and calculated for further evaluation of the mechanism of late distal SINE. RESULTS: Only the area oversizing ratio between true lumen and the distal selected stent graft at the presumed distal end of stent grafting was found as a significant predictive factor of SINE before procedure (4.00 ± 2.96 vs 1.98 ± 0.66 for SINE vs non-SINE, respectively; P = .031). The significant difference of the expansion mismatch ratio of true lumen between the 2 groups was found not only in the size measurement of mean diameter (1.48 ± 0.29 vs 1.22 ± 0.15; P = .039), but also in the area (2.39 ± 0.85 vs 1.58 ± 0.42; P = .031) and circumference (1.43 ± 0.27 vs 1.18 ± 0.14; P = .016) after stent grafting. CONCLUSIONS: We found that taper ratio is not an optimal criteria for stent graft size selection and distal oversizing calculated by true-lumen area is a significant factor causing delayed distal SINE. Use of the prestenting area oversizing ratio should be limited.The Journal of thoracic and cardiovascular surgery 10/2012; · 3.41 Impact Factor