Optimal Treatment of Chronic Dissection Chun-Che Shih 施俊哲 MD, Ph.D. Chief, Professor Institute of Clinical Medicine National Yang Ming University Division of Cardiovascular Surgery Taipei Veterans General Hospital Taipei, Taiwan.
Aortic dissection (55% of TEVAR in Taipei VGH) Residual & acute Type A Complicated Type B Symptomatic IMH
Aortic Remodeling after Endovascular Repair with Stainless Steel-based Stent Graft in Acute and Chronic Type B Aortic Dissection Shih CC et al. JVS 2012,55:1600-161
Type B aortic dissection patients demographic Acute n=33 Chronic n=29 P valve or reason Age 60.6 ± 16.6 63.2 ± 12.8 0.21 Sex 25 ± 75.8% 25 ± 86.2% 0.29 Height 168.3 ± 19.6 168.3 ± 8.9 0.29 Weight 68.3 ± 13.8 69.3 ± 13.2 0.87 Etiology of dissection Artherosclerosis 19 (57.6%) 16 (55.2%) 0.84 HTN 11 (33.3%) 10 (34.5%) 0.92 Other 3 (9.1%) 3 (10.3%) 0.86 Connective tissue disorder 1 (3.0%) 2 (6.9%) Trauma 2 (6.1%) 0 Other 0 1 (3.4%) Indications for operation Impending rupture 10 (30.3%) 6 (20.6%) 0.388 Malperfusion 5 1 Refractory HTN 14 13 Refractory pain 19 14 More than one symptom Shih CC et al. Aortic remodeling after endovascular repair with stainless steel-based stent graft in acute and chronic type B aortic dissection JVS 2012,55:1600-1610
Short-term Follow up Medium follow-up: 30 months (0-53 months) 4 years overall survival: 86.7%
Thrombosis and Regression of False Lumen after TEVAR (Complicated Type B) Shih,C.C. et al. JVS 2012,55:1600-1610.
Acute vs. Chronic Acute: symptomatic patient treated within 14 days
Complete false lumen thrombosis after coverage of whole aortic communicating holes Before endografting Post endografting Chronic Type B Dissection: 6 Months After Stent Grafting First TEVAR in Taiwan at Taipei VGH on 2006-10-31
Chronic dissection Acute dissection 6 Months After Stent Grafting Comparing chronic with acute dissection 6 months after stent grafting, the early intervention is more impressive with false lumen complete obliteration
Remodeling of Aorta--True and False Lumen * * * * * * Figure 4 : Both acute and chronic dissection groups, the true lumen are dilated at different measure level along with time Shih,C.C. et al. JVS 2012,55:1600-1610.
Remodeling of Aorta--True and False Lumen * * * * * * Figure 4: False lumen regression are significantly except over the C and D level of chronic dissection where is the non stenting aortic segment. Shih,C.C. et al. JVS 2012,55:1600-1610.
假腔重構 False Lumen Regression Total thoracic false lumen Thrombosis rate: 84 % patients
False Lumen Regression Complete regression with obliteration of false lumen : 41 %
血管再塑形 Thrombosis and Regression (II) Acute (n=31) Chronic (n=26) P value Thrombosis level No thrombosis.(within stent level) 3 (9.7 ) 1 (3.8) 0.391 Partial thrombosis (level between diaphragm and distal end of stent graft) 3 (9.7) 2 (7.7) >1.000 Complete thrombosis (diaphragm level) 25 (80.6) 23 (88.5) 0.488 Regression level No Regression. (within stent level) 9 (29.0) 15 (57.7) 0.029 Partial Regression (level between diaphragm and distal end of stent graft) 5 (16.1) 3 (11.5) 0.715 Complete regression (diaphragm level) 17 (54.8) 8 (30.8) 0.068 No significant difference of complete thrombosis rate between acute and chronic group, complete regression rate (to diaphragm level) seems better in acute group
Stent Graft Induced New Entry Distal SINE Factors predictive of distal stent graft-induced new entry after arch elephant trunk repair with stainlesssteel based device in aortic dissection Shih et al. JTCVS 2013;146:623-630 Re-intervention for Distal Stent Graft-induced New Entry after Endovascular Repair in Aortic Dissection Shih CC et al J Vasc Surg 2013;57:64-71
5 days post Op 1 years post Op 2 years post Op chronic type B dissection
Acute : 18.9% Mean follow-up: 14.0 ± 4.8 months Chronic: 35.7% Mean follow-up: 24.8 ± 5.9 months P =.121 3 years post Op Late Distal Stent graft Induced New Entry (SINE)
Device Related Complications Device related complications Acute (n=33) Chronic (n=28) P Access site hematoma 1(3.0) 0 >1.000 Access site lymphocele 1(3.0) 0 >1.000 Endoleak type Type I 0 0 Type II 3 (9.1) 1 (3.6) 0.618 Type III 0 2 (7.1) 0.207 Type V 0 1 (3.6) 0.459 Device Distal injury 6 (18.9) 10 (35.7) 0.121 Distal injury required intervention 2 (6.1) 1 (3.6) >1.000 Follow-up proximal dissection 0 2 (7.1) 0.459
Re-intervention of Distal SINE 5 % Re-intervention for Distal Stent Graft-induced New Entry after Endovascular Repair in Aortic Dissection Shih CC et al J Vasc Surg 2013;57:64-71
Re-intervention for Distal Stent Graft-induced New Entry after Endovascular Repair in Aortic Dissection Shih CC et al J Vasc Surg 2013;57:64-71
Factors Predictive of Distal Stent Graft-induced New Entry Shih CC et al. JTCVS 2013;146:623-630 Shih CC et al J Vasc Surg 2013;57:64-71
How to measure of distal size of true lumen of aortic dissection? Longitudinal maximal diameter Average of longitudinal & transverse maximal diameter Area and circumference Shih CC et al JTCVS 2013; 146:623-630 Shih CC et al J Vasc Surg 2013;57:64-71
Pre-stent Graft Oversizing Ratio = (X G / X A ) 1 Oversizing Ratio: The ratio between the size of distal end of selected graft and distal landing zone before procedure. Shih CC et al JTCVS 2013; 146:623-630 Shih CC et al J Vasc Surg 2013;57:64-71
Table 4: Pre-stent Graft Oversizing Ratio (mean ± SD) SINE Non-SINE P value Longitudinal maximal diameter Longitudinal maximal diameter 0.35±0.31 0.16±0.17 0.208 2.74±1.56 1.73±0.51 0.082 Mean Diameter 0.94±0.47 0.61±0.18 0.115 Area 4.00±2.96 1.98±0.66 0.031 * Circumference 0.77±0.39 0.50±0.19 0.115 Pre-stent Graft Area over sizing more than 4 times is highly related with distal SINE * p<0.05, significant difference Shih CC et al JTCVS 2013; 146:623-630 Only area size measurement with significant difference between groups.
Expansion Mismatch Ratio of True Lumen = X G / X A 2cm During follow up, the ratio between the size of distal end of stent graft and 2 cm distal of non stented segment of true lumen is called expansion mismatch ratio of true lumen size. Shih CC et al JTCVS 2013; 146:623-630 Shih CC et al J Vasc Surg 2013;57:64-71
Table 6 Expansion mismatch ratio of true lumen= X G / X A 2cm (mean ± SD) SINE Non-SINE P value Longitudinal maximal diameter Longitudinal maximal diameter 1.29±0.28 1.13±0.17 0.343 1.89±0.54 1.45±0.38 0.115 Mean Diameter 1.48±0.29 1.22±0.15 0.039 * Area 2.39±0.85 1.58±0.42 0.031 * Circumference 1.43±0.27 1.18±0.14 0.016 * Post stent graft : distal area expansion mismatch over 2.4 times is highly related to distal SINE The result showed that the parameter of mean diameter, area and circumference calculatioon with significant differences between groups Shih CC et al JTCVS 2013; 146:623-630
Stent Graft Induced New Entry Proximal SINE (RTAD) TEVAR RELATED TYPE A DISSECTION
Device Related Complications Device related complications Acute (n=33) Chronic (n=28) P Access site hematoma 1(3.0) 0 >1.000 Access site lymphocele 1(3.0) 0 >1.000 Endoleak type Type I 0 0 Type II 3 (9.1) 1 (3.6) 0.618 Type III 0 2 (7.1) 0.207 Type V 0 1 (3.6) 0.459 Device Distal injury 6 (18.9) 10 (35.7) 0.121 Distal injury required intervention Incidence: 3.2 % 2 (6.1) 1 (3.6) >1.000 Follow-up proximal dissection 0 2 (7.1) 0.459 Shih CC et al. Aortic remodeling after endovascular repair with stainless steel-based stent graft in acute and chronic type B aortic dissection JVS 2012,55:1600-1610
Bird Beak configuration 18 Month after TEVAR
The Risk of TEVAR related RAD Unfavorable Distal arch pathology: Marfan s syndrome, sharp angle, Graft oversizing Bird Beak poor wall apposition
Type II endoleak? Calcification spot 3 Month after TEVAR
The Risk of TEVAR related RAD Unfavorable proximal landing site with calcification Type II endoleak
3 months after TEVAR New Tear hole related with the oversided 46 mm graft
Related with Proximal Bare Stent? 1 Month after TEVAR
Summary Low rate of mortality and complications after TEVAR for aortic dissection. High incidence & low mortality of late distal SINE Complicated distal SINE can be successfully resolved by distal endograft implantation. Excessive oversizing of the stent graft may be a significant factor with regards to late proximal and distal SINE.. Pre-stenting GO of area ratio is an important index of SINE prediction for preoperative stent graft selection. The area ratio more than 4.00 should be avoided 35
Optimal Design and Strategy for Dissection Pathology? ( for distal SINE prevention)
Distal Remodeling vs. Paraplegia To prevent distal SINE and better distal remodeling, distal bare dissection stenting one of option and undergoing clinical trial now..
Dissection Solution for Treating Progress Dissection Pathology The PETTICOAT Concept
Bottom up Technique
Bottom up technique : extreme compressed distal true lumen anatomy Taper Graft : taper 8 mm Proximal large graft secondary : 32-200 Distal small graft first : 22-100 Chronic Dissection: Distal small graft first implantation procedure
Optimal Design for Dissection Pathology? ( for Proximal SINE prevention)
Pro-Form vs. Z-Trak Plus Apposition TX2 Z-Trak Plus Apposition TX2 ProForm Improve distal arch conformability and avoid bird beak configuration
Zenith TX2 Dissection Endovascular Graft The change of Proximal Tapered Component: proximal Pro-form design with removal of proximal barb and taper 4 to taper 8
Zenith TX2 Dissection Endovascular Graft Proximal Tapered Component Distal bare stent component
Conformable GORE TAG Thoracic Endoprosthesis 2013 first and only thoracic stent graft approved in US for aneurysm, transection and acute and chronic type B dissection Dissection design of Conformable GORE TAG
Future Design Concept for Dissection Conformability without Compromise Arch No barbs or bare springs Compression resistant Off-the-shelf tapered designs
Valiant Captivia Thoracic Stent Graft System From Medtronic Receives FDA Approval for Treating Aortic Dissections January 28, 2014 1:43 U.S. Medtronic DISSECTION Trial Proximal Bare Stent Design
Controversial? In the EuREC study: 60% of retrograde type A may related to the trauma caused by the semirigid stent graft Device design : Proximal bare spring design may increase the risk for new entry tear in treatment of type B dissection, particularly in patients with fragile aortic wall (Dong ZH et al.). Close Observation? Dong ZH, Fu WG, Wang YQ, Guo da Q, Xu X, Ji Y, et al. Retrograde type A aortic dissection after endovascular stent graft placement for treatment of type B dissection. Circulation 2009;119:735-41.
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