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. · 3.59 Impact Factor
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ABSTRACT: Stent graft-induced distal redissection (SIDR) is one of the major concerns in the durability of endovascular repair for complicated Stanford type B aortic dissection. The characteristics and means of prevention of this complication remain unknown. From April 1997 to March 2010, 674 patients with type B aortic dissections were treated primarily by thoracic endovascular aortic repair (TEVAR) at our center. Criteria for inclusion in this study were treatment primarily with TEVAR and an estimated mismatch rate (ratio of distal diameter of stent graft to long diameter of true lumen) greater than 120%. By this protocol, 465 patients were included in this study and were retrospectively analyzed. Among them, 266 patients were treated in the acute phase, and 199 were treated in the chronic phase. A total of 311 patients were treated with standard TEVAR and 154 patients with TEVAR + restrictive bare stent (RBS). The preoperative mismatch rate (measured as the preoperative long diameter of the true lumen at the level of the intended distal end of the stent graft) of the SIDR was significantly higher than that of the non-SIDR (192.7 ± 54.9% vs 131.9 ± 10.4%; P ＜ .05). The follow-up mismatch rate of the SIDR was significantly higher than that of the non-SIDR (145.4 ± 34.6 vs 120.3 ± 16.1; P ＜ .05). Compared with the standard TEVAR, TEVAR + RBS was associated with a lower incidence of SIDR (0% vs 2.9%; P = .033) and less secondary intervention (3.9% vs 9.3%; P = .040). Placement of the RBS significantly expanded the true lumen at the level of the descending aorta with the narrowest true lumen and at the level of the distal end of the stent graft. The mismatch between the distal diameter of the stent graft and the diameter of the compressed true lumen seems to be the major factor in the occurrence of SIDR. Placement of an RBS, as an adjunctive technique to TEVAR, could reduce the incidence of SIDR. On the basis of early- to midterm observations, RBSs may improve morphological remodeling of the dissected aorta at certain levels.Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter 02/2013; 57(2 Suppl):44S-52S. · 2.98 Impact Factor
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ABSTRACT: Objectives – This study analyzed the mechanism and risk factors of thoracic aortic aneurysm expansion due to late distal stent graft-induced new entry (dSINE).Background – This late complication of thoracic endovascular aneurysm repair (TEVAR) for aortic dissection is under-recognized but potentially life-threatening.Methods – In 142 patients who underwent TEVAR with endovascular entry sealing for acute and chronic aortic type B dissection, using commercially available straight (non-tapered) stent-grafts, we examined the oversizing rate, the aortic taper ratio, and the need for reintervention.Results – Nine of 142 patients developed thoracic aortic aneurysm expansion due to dSINE after TEVAR. The median follow-up was 47.5±37.4 months. There was a significant difference in the distal stent–aorta angle between the patients with and without dSINE (149.08±15.09° vs. 166.72±12.47°, P<0.005). Patients with dSINE showed a significantly higher taper ratio of the true lumen of the aorta (40.9±14.13% vs. 25.36±20.2%, P<0.05). There was also a significant difference in the oversizing of the stent-graft in the distal landing zone (95.88±49.3% vs. 55.94±36.23%, P<0.01). All patients with dSINE underwent a secondary endograft procedure without any complications or deaths. In 7 cases we used a custom-made, highly tapered stent-graft.Conclusions – Lifelong follow-up of patients is mandatory after TEVAR. A stent-graft with a tapered design should be used in aortic dissection to avoid oversizing and devastating late complications. © 2014 Wiley Periodicals, Inc.Catheterization and Cardiovascular Interventions 07/2014; · 2.51 Impact Factor