Thoracic Endovascular Aortic Repair For Type Research Articles

“Loss of landing zone”—Stabilizing endovascular treatment solutions in the aortic arch after thoracic endovascular aortic repair

Addressing proximal complications that arise after endovascular aortic repair for type B aortic dissection, such as type Ia endoleaks, “bird-beaking” of the thoracic endovascular aortic repair (TEVAR) stent, retrograde type A dissection, and postdissection aneurysms, bears considerable complexities. We present a novel and safe method for open arch repair that can ensure a secure and efficient approach for TEVAR complications. The key element of the operative technique is approximating the grafted stent portion to the aortic wall and the arch prosthesis. The technique has successfully been implemented in 11 patients, who received secondary open arch repair from 2019 to 2022 after TEVAR for type B dissection. Our objective is not only to introduce this reliable concept but also to provide a comprehensive demonstration of its advantages and disadvantages compared with currently used open treatment methods and discuss patient outcomes after secondary open arch repair.

Preclinical Evaluation of a Modular Inner-Branched Stent Graft to Reconstruct the Left Subclavian Artery in Thoracic Endovascular Aortic Repair: Experimental Study in Pigs.

In approximate 40% of thoracic endovascular aortic repair (TEVAR) procedures, the left subclavian artery (LSA) needs to be covered to obtain sufficient proximal sealing zone. To preserve the LSA during the TEVAR for type B aortic dissection (TBAD) adjacent to LSA, our team designed a modular single inner-branched stent graft. This study was performed to evaluate the safety and feasibility of deploying a modular single inner-branched stent graft in a porcine model. Modular inner-branched stent grafts were implanted in 14 pigs via right femoral and right carotid arterial access. Computed tomography angiography (CTA) and angiography were performed in all pigs to appraise the morphological characteristics of the stent grafts at the end of follow-up. The pigs were then euthanized, and tissues were collected for gross and histological examination. The technical success rate was 100% (14/14). One pig suddenly died 5 hours after operation, and 1 pig died after completing the follow-up CTA. During the follow-up period, all surviving pigs showed good mental state, normal diets and activities. Computed tomography angiography examinations showed that all stent grafts were intact without fracture. All bridging covered stents were patent. Angiography showed that the position, shape, and adhesion of the stent grafts were good, and no obvious endoleaks were found. Histological examination showed that the biocompatibility of the stent grafts was good. This study's outcomes demonstrate that it is safe and feasible to deploy a modular single inner-branched stent graft in a porcine model. This device is the first modular device designed to treat TBAD adjacent to LSA in China. This device is a modular two-component system consisting of a thoracic aortic stent graft with a retrograde inner branch and a bridging covered stent. The modular design and the retrograde inner branch are the two important innovations of this device. Theoretically, the device could make it easier and safer for clinicians to treat TBAD adjacent to the LSA.

Cardiac Pulsatile Helical Deformation of the Thoracic Aorta Before and After Thoracic Endovascular Aortic Repair of Type B Dissections.

Type B aortic dissections propagate with either achiral (nonspiraling) or right-handed chiral (spiraling) morphology, have mobile dissection flaps, and are often treated with thoracic endovascular aortic repair (TEVAR). We aim to quantify cardiac-induced helical deformation of the true lumen of type B aortic dissections before and after TEVAR. Retrospective cardiac-gated computed tomography (CT) images before and after TEVAR of type B aortic dissections were used to construct systolic and diastolic 3-dimensional (3D) surface models, including true lumen, whole lumen (true+false lumens), and branch vessels. This was followed by extraction of true lumen helicity (helical angle, twist, and radius) and cross-sectional (area, circumference, and minor/major diameter ratio) metrics. Deformations between systole and diastole were quantified, and deformations between pre- and post-TEVAR were compared. Eleven TEVAR patients (59.9±4.6 years) were included in this study. Pre-TEVAR, there were no significant cardiac-induced deformations of helical metrics; however, post-TEVAR, significant deformation was observed for the true lumen proximal angular position. Pre-TEVAR, cardiac-induced deformations of all cross-sectional metrics were significant; however, only area and circumference deformations remained significant post-TEVAR. There were no significant differences of pulsatile deformation from pre- to post-TEVAR. Variance of proximal angular position and cross-sectional circumference deformation decreased after TEVAR. Pre-TEVAR, type B aortic dissections did not exhibit significant helical cardiac-induced deformation, indicating that the true and false lumens move in unison (do not move with respect to each other). Post-TEVAR, true lumens exhibited significant cardiac-induced deformation of proximal angular position, suggesting that exclusion of the false lumen leads to greater rotational deformations of the true lumen and lack of true lumen major/minor deformation post-TEVAR means that the endograft promotes static circularity. Population variance of deformations is muted after TEVAR, and dissection acuity influences pulsatile deformation while pre-TEVAR chirality does not. Description of thoracic aortic dissection helical morphology and dynamics, and understanding the impact of thoracic endovascular aortic repair (TEVAR) on dissection helicity, are important for improving endovascular treatment. These findings provide nuance to the complex shape and motion of the true and false lumens, enabling clinicians to better stratify dissection disease. The impact of TEVAR on dissection helicity provides a description of how treatment alters morphology and motion, and may provide clues for treatment durability. Finally, the helical component to endograft deformation is important to form comprehensive boundary conditions for testing and developing new endovascular devices.

Factors affecting distal false lumen enlargement after thoracic endovascular aortic repair for type B aortic dissection

ObjectiveTo investigate the factors influencing distal false lumen enlargement after thoracic endovascular aortic repair (TEVAR) for type B aortic dissection. Materials and methodsData were collected on patients with type B aortic dissection who underwent TEVAR from January 2008 to August 2022. Patients were divided into a distal aortic segmental enlargement (DSAE) group and a non-DSAE group based on whether the distal false lumen was dilated more than 5 mm on computed tomographic angiography (CTA) images. To analyze the independent influences on distal false lumen dilatation after TEVAR, the variables with a P value < 0.05 during univariate analysis were included in the binary logistic regression analysis model. ResultsA total of 335 patients were included in this study, with 85 in the DSAE group and 250 in the non-DSAE group. The mean age was 52.40 ± 11.34 years, 289 (86.27%) were male patients, and the median follow-up time was 6.41 (11.99–29.99) months. There were significant differences in Marfan syndrome, chronic obstructive pulmonary disease (COPD), and follow-up time between the two groups. In terms of morphology, there were statistically significant differences in the number of tears, the size of the primary tear, and the length of dissection between the two groups. Binary logistic regression analysis indicated that Marfan syndrome, COPD, and the primary tear size were associated with distal false lumen dilatation. ConclusionsMarfan syndrome, COPD, and the primary tear size influence distal aortic segmental enlargement after TEVAR in type B aortic dissection patients.

Application of "Fabulous" stent system to improve aortic remodeling after TEVAR for type B aortic dissection.

Application of "Fabulous" stent system to improve aortic remodeling after TEVAR for type B aortic dissection.

Preoperative systemic inflammatory response index predicts long-term outcomes in type B aortic dissection after endovascular repair.

ObjectivesInflammation is a hallmark of the initial development and progression of aortic dissection. This study aimed to investigate the value of preoperative inflammatory biomarkers in predicting aorta-related adverse events (AAEs) after thoracic endovascular aortic repair (TEVAR) for type B aortic dissection.MethodsWe included all patients who underwent TEVAR for type B aortic dissection between November 2016 and November 2020 in this single-center, retrospective cohort study. Patients were divided into two groups: the AAEs group (n = 75) and the non-AAEs group (n = 126). Preoperative inflammatory biomarkers were recorded, including neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), platelet-to-lymphocyte ratio (PLR), systemic immune inflammation index (SII), and systemic inflammatory response index (SIRI). Patients were followed-up for the development of AAEs. Prediction accuracy of inflammatory biomarkers for AAEs were evaluated using the area under the receiver operating characteristic curves.ResultsThis study included 201 patients, of whom 80.0% were men, with a mean age of 59.1 ± 12.5 years. A total of 75 patients developed AAEs after TEVAR. The AUCs of NLR, MLR, PLR, SII, and SIRI for AAEs were.746,.782,.534,.625 and.807, respectively. Age and SIRI were independent risk factors for the AAEs after TEVAR (HR 3.264, p <.001; HR 4.281, p <.001, respectively). Survival analysis revealed significantly lower AAE-free status in patients with preoperative SIRI > = 4 (p <.001).ConclusionIncreased preoperative SIRI and age are independent risk factors for AAEs after TEVAR in type B aortic dissection.

Looping wire technique to facilitate true lumen wiring during TEVAR in type B aortic dissection with aneurysmal degeneration: A case report.

Introduction and importanceWiring true lumen during Thoracic Endovascular Aortic Repair (TEVAR) is sometimes difficult in complicated Type B Aortic Dissection (TBAD).Case presentationWe treated a TBAD patient with large false lumen, compressed true lumen and multiple entries. After repeated wire misdirection to false lumen, we tried a new technique in which the wire in the false lumen was looped after entrance to true lumen and pushed distally. The looped wire was then used as guide to advance a second wire to the ascending aorta. TEVAR could then be completed with good result.DiscussionWiring the true lumen might be one of the most challenging steps during TEVAR in complicated TBAD. Several methods have been used to overcome the problems, but the cost and availability might be a problem in some countries. The looping wire technique may serve as an alternative method of guiding the process of wiring the true lumen during complicated TEVAR.ConclusionLooping wire technique can be used as an alternative method to facilitate true lumen wiring during TEVAR.

In Situ Laser Fenestration for Delayed Left Subclavian Artery Revascularization Following Thoracic Endovascular Aortic Repair of Type B Aortic Dissection.

In situ laser fenestration (ISLF) is currently used to reconstruct the aortic major branches during thoracic endovascular aortic repair (TEVAR). To our knowledge, there have been no reports on the application of ISLF for delayed revascularization of the LSA previously sealed in TEVAR. This report describes 5 patients who underwent ISLF for delayed LSA revascularization, with a technical success rate of 80%. No endoleakage occurred, and stents remained patent during more than 6-month follow-up. ISLF is an effective, safe and minimally invasive method for delayed revascularization of the LSA following TEVAR for type B aortic dissection (TBAD) when patients are selected appropriately.

Retrograde Type A Aortic Dissection after Thoracic Endovascular Aortic Repair: Incidence, Time Trends and Risk Factors

To review the incidence of retrograde type A aortic dissection (RTAD) after thoracic endovascular aortic repair (TEVAR) of patients with type B aortic dissection, and to investigate its time trends and underlying risk factors. The incidence rate of RTAD after TEVAR for type B aortic dissection was gathered as a cumulative pool for each year in meta-analysis. Linear regression was used to establish the temporal trend of RTAD incidence. Annual decrease rate was calculated for the fulltime frame. Sixty-six articles were included in this study, which represented 11,149 patients enrolled since 1994, and the research published between 2000 and 2019. The overall pooled rate of RTAD incidence is 2.20% (95% confidence interval 0.0162-0.0284; P < 0.0001). The incidence numbers fluctuated for many years while continuing to decline, ultimately reaching a valley in 2016-2017. The linear regression analysis identified a 0.4% decrease in incidence rate along with a declining oversize rate of stent-grafts. The overall average incidence of RTAD in the past 21 years was 2.2%. The downward incidence trend may be attributed to the lower oversize rate and the improved design of stent-grafts, as well as sophisticated manipulation and delayed TEVAR intervention.

Branch Vessel Patency after Thoracic Endovascular Aortic Repair for Type B Aortic Dissection

Thoracic endovascular aortic repair (TEVAR) for type B aortic dissections is used to promote false lumen (FL) thrombosis and favorable aortic remodeling, but its impact on occlusion of FL origin branch vessels has not been widely described. We compare FL versus true lumen (TL) branch vessel patency after TEVAR. Patients treated by TEVAR for type B aortic dissection in zones 2-5 in the Vascular Quality Initiative from 2009 to 2018 were evaluated. The primary outcome was postoperative branch patency. Secondary outcomes were need for branch vessel intervention, preoperative origin, and postoperative patency of individual branch vessels (celiac, superior mesenteric artery, renal arteries, and iliac arteries). A subset analysis was performed comparing acute and chronic dissections. Of 11,774 patients, 1,484 met criteria for analysis. The left renal was the most common to have FL origin (21.6%), whereas right and left common iliac arteries were the most likely to originate off both lumens (BLs; 22% and 24%). Branch vessels that originated from the TL, FL, BLs, or were obstructed had postoperative patency rates of 99%, 99%, 99%, and 87% (P<0.0001). Branch vessel treatment was performed in 5% of patients. The right (2.5%) and left (2.8%) renal arteries were the most frequently obstructed branches postoperatively. On multivariate analysis, preoperatively obstructed branches (odds ratio 0.03, P<0.0001) were negatively associated with postoperative branch patency and branch vessel treatment (odds ratio 3.8, P=0.004) was positively associated with postoperative patency. FL or BL origin, number of zones covered by TEVAR, urgency, dissection chronicity (acute versus chronic), and demographics were not independently associated with patency. These findings remained unchanged in the subset analysis of only acute dissections. Branch vessel patency rates after TEVAR for a type B aortic dissection are high and are not significantly different for FL or BL origin vessels compared with TL vessels. Branches that are patent before TEVAR almost always remain patent after TEVAR, but branch vessel stenting may be required in less than 5%.

Management of Renal Arteries in Conjunction with Thoracic Endovascular Aortic Repair for Complicated Stanford Type B Aortic Dissection: The Japanese Multicenter Study (J-Predictive Study).

Background Management of abdominal branches associated with Stanford type B aortic dissection is controversial without definite criteria for therapy after thoracic endovascular aortic repair (TEVAR). This is in part due to lack of data on natural history related to branch vessels and their relationship with the dissection flap, true lumen, and false lumen. Purpose To investigate the natural history of abdominal branches after TEVAR for type B aortic dissection and the relationship between renal artery anatomy and renal volume as a surrogate measure of perfusion. Materials and Methods This study included patients who underwent TEVAR for complicated type B dissection from January 2012 to March 2017 at 20 centers. Abdominal aortic branches were classified with following features: patency, branch vessel origin, and presence of extension of the aortic dissection into a branch (pattern 1, supplied by the true lumen without branch dissection; pattern 2, supplied by the true lumen with branch dissection, etc). The branch artery patterns before TEVAR were compared with those of the last follow-up CT (mean interval, 19.7 months) for spontaneous healing. Patients with one kidney supplied by pattern 1 and the other kidney by a different pattern were identified, and kidney volumes over the course were compared by using a simple linear regression model. Results Two hundred nine patients (mean age ± standard deviation, 66 years ± 13; 165 men and 44 women; median follow-up, 18 months) were included. Four hundred fifty-nine abdominal branches at the last follow-up were evaluable. Spontaneous healing of the dissected branch occurred in 63% (64 of 102) of pattern 2 branches. Regarding the other patterns, 6.5% (six of 93) of branches achieved spontaneous healing. In 79 patients, renal volumes decreased in kidneys with pattern 2 branches with more than 50% stenosis and branches supplied by the aortic false lumen (patterns 3 and 4) compared with contralateral kidneys supplied by pattern 1 (pattern 2 vs pattern 1: -16% ± 16 vs 0.10% ± 11, P = .002; patterns 3 and 4 vs pattern 1: -13% ± 14 vs 8.5% ± 14, P = .004). Conclusion Spontaneous healing occurs more frequently in dissected branches arising from the true lumen than in other branch patterns. Renal artery branches supplied by the aortic false lumen or a persistently dissected artery with greater than 50% stenosis are associated with significantly greater kidney volume loss. © RSNA, 2019 Online supplemental material is available for this article.

In situ diode laser fenestration of aortic arch stent grafts during thoracic endovascular aortic repair of Stanford type A aortic dissection.

The aim of the study was to evaluate the feasibility, safety, and effectiveness of in situ diode laser fenestration of thoracic endovascular aortic repair (TEVAR) stent grafts to treat Stanford type A aortic dissection. Fifty-eight patients with acute or subacute Stanford type A aortic dissection treated with in situ diode laser fenestration during TEVAR under cerebral circulation protection with an extracorporeal bypass were reviewed retrospectively. Routine postoperative outcomes were recorded and assessed. Computed tomography angiography (CTA) was performed during the follow-up after 3, 6 and 12 months. Procedural success was achieved in 53 patients (91.4%). The average procedure time was 162±36 minutes. One patient died of pericardial tamponade during intervention, and one died of severe pneumonia after the intervention. Except for two minor strokes, no more fenestration-related complications occurred at 30 days and 12 months after the intervention. CTA imaging demonstrated 100% primary patency for the left subclavian artery and carotid arteries with favourable aortic remodelling after TEVAR during the follow-up. Two patients had a type Ia endoleak and one other a type II endoleak. In situ diode laser fenestration during TEVAR for type A aortic dissection was found to be feasible, safe, and effective, and may be beneficial as a less invasive approach.

Distal Stent Graft-Induced New Entry After TEVAR of Type B Aortic Dissection: Experience in 15 Years

Experience is limited with distal stent graft-induced new entry (SINE) after thoracic endovascular aortic repair (TEVAR) of type B dissection (TBAD). We report the management strategy and outcomes in such patients. Clinical data were analyzed for 95 patients (age, 53.2 ± 10.9 years; 82 men) who presented with distal SINE after TEVAR for TBAD. Follow-up was 100% for 7.2 ± 3 years after primary TEVAR. Distal SINE occurred at a mean of 2.7±2.4 years. Re-TEVAR was performed for 78, with routine stent grafts in 64 and a more tapered graft in 14. Three patients were managed surgically and 14 medically. Two patients died after re-TEVAR. During follow-up at 5.8 ± 2.9 years, late death occurred in 19 patients, 7 with medical therapy and 12 with re-TEVAR. Distal SINErecurred in 11 at 3.5 ± 1.7 years after re-TEVAR. Reintervention significantly improved survival up to 8years compared with medical therapy (88.3% vs 63.5%, p= 0.001). In 64 patients with routine stent grafts, mortality was 24%, distal SINE recurred in 20%, and recurrence-free survival was 56% at 6 years. Neither death nor recurrence of SINE occurred in 14 patients with a more tapered stent graft. Predictors for distal SINE after primary TEVAR were stent graft length (hazard ratio, 0.984; p= 0.037) and chronic phase (hazard ratio, 1.725; p= 0.049). In TBAD patients with distal SINE after TEVAR, reintervention with re-TEVAR could improve long-term survival significantly. Recurrence of distal SINE was high after re-TEVAR using routine stent grafts. More tapered stent grafts may be helpful in preventing the recurrence of distal SINE.

The application of reserving the left subclavian artery by fenestration of domestic stent graft in TEVAR of type B dissection with unfavourable proximal landing zone

Objective To explore the preliminary results of application of reserving the left subclavian artery by fenestration of domestic stent graft in the thoracic endovascular aortic repair (TEVAR) of type B dissection with unfavourable proximal landing zone. Methods From October 2015 to January 2018, a total of 13 patients with type B aortic dissection without healthy proximal landing zones underwent TEVAR using fenestration of domestic stent graft in our hospital. Computed tomography angiography (CTA) data were measured before surgery. Digital subtraction angiography (DSA) was conducted after surgery. All patients underwent CTA or ultrasound examination during follow-up. Operation success rate, survive rate, patency of left subclavian artery and complications were analyzed. Results All the patients were deployed fenestrated endografts successfully. No proximal endoleak happened during perioperative period. Delirium occurred in 1 case during 7 postoperative days and fully recovered with the medical treatment. The mean follow-up period was (9.8±9.5)months (range, 1-29 months). 11 patients underwent CTA and 2 patients underwent ultrasound examination during follow-up. During period of following up, no patients died, no proximal endoleak appeared, and all the left subclavian arteries reserving by fenestration. Conclusions Reserving the left subclavian artery by fenestration of domestic stent graft in TEVAR of type B dissection with hostile proximal sealing zone is economical, safe and feasible, which expand the indication of TEVAR for aortic dissection, and the long-term outcomes of this technique need to be assessed in the future. Key words: Aneurysm, dissecting/SU; Aortic diseases/SU; Subclavian artery; Stents; Aorta, thoracic/SU

Aortic morphologic findings after thoracic endovascular aortic repair for type B aortic dissection.

Thoracic endovascular aortic repair (TEVAR) is used in the treatment of type B aortic dissections. Information related to aortic morphologic findings and the condition of the abdominal aorta after TEVAR is limited. To analyze aortic morphologic findings after TEVAR for type B aortic dissections. After a retrospective database review, the data for 30 patients who underwent TEVAR from January 1, 2007, through December 31, 2013, for type B aortic dissection were analyzed. Imaging software was used to calculate aortic diameters and volumes of the aorta on computed tomography (CT) or magnetic resonance imaging (MRI). Mean follow-up was 14.4 months. We performed TEVAR to cover proximal thoracic aorta tears in patients who underwent acute or chronic type B aortic dissections. Aortic morphologic findings of pre-TEVAR CT or MRI were compared with the most recent findings of post-TEVAR CT or MRI. Frequency of thoracic false lumen thrombosis (FLT) and false lumen patency (FLP) was determined and the effect on post-TEVAR aortic morphologic findings analyzed. Mean (SD) TEVAR increased true lumen diameter (19.50 [6.92] mm to 31.19 [5.36] mm, P < .001) and volume (77.92 [41.70] mL to 166.95 [69.69] mL, P < .001) and decreased false lumen diameter (29.77 [12.55] mm to 21.92 [12.05] mm, P = .001) on post-TEVAR CT or MRI when compared with pre-TEVAR scans. Seventy percent of patients experienced thoracic FLT; 30% had FLP. True lumen volume expansion and false lumen volume regression occurred in patients with FLT (82.07 [46.95] mm to 180.55 [77.99] mm, P < .001 and 161.84 [106.36] mm to 115.76 [140.77] mm, P = .002, respectively) and FLP (68.23 [21.43] mm to 128.22 [21.46] mm, P < .001 and 238.64 [174.00] mm to 198.93 [120.46] mm, P = .04, respectively). Patients with FLT had increased true lumen diameter (15.67 [6.43] mm to 26.13 [7.62] mm, P < .001) and volume (54.86 [30.52] mL to 88.08 [41.07] mL, P = .001) in the abdominal aorta after TEVAR, with no change in total abdominal aortic volume (161.94 [70.12] mL vs 160.36 [82.11] mL, P = .90). Total abdominal aortic volume significantly increased in patients with thoracic FLP (187.24 [89.88] mL to 221.41 [82.64] mL, P = .02). Favorable aortic remodeling of the thoracic aorta occurs after TEVAR for type B aortic dissections in patients with thoracic FLT and FLP. However, failure to achieve thrombosis of the thoracic false lumen negatively influences aortic morphologic findings of the contiguous abdominal aorta.

Imaging Follow-up of Endovascular Repair of Type B Aortic Dissection with Dual-Source, Dual-Energy CT and Late Delayed-Phase Scans

PurposeTo evaluate the diagnostic performance of dual-energy (DE) computed tomography (CT) after thoracic endovascular aortic repair (TEVAR) of type B dissection, and to investigate the value of late delayed (LD) acquisition in endoleak detection and false lumen patency assessment. Materials and MethodsTwenty-four patients with TEVAR for type B dissection underwent 53 tripe-phase CT examinations. Single-source unenhanced acquisition was followed by single-source arterial-phase and DE LD phase (300-s delay) imaging. Virtual noncontrast images were generated from DE acquisition. Two blinded radiologists retrospectively evaluated the cases in three reading sessions: session A (triphasic protocol), session B (virtual noncontrast and arterial phase), and session C (virtual noncontrast and arterial and LD phases). Endoleak detection accuracy during sessions B and C compared with session A (reference standard) was investigated. False lumen patency was assessed. Effective radiation dose was calculated. ResultsSession A revealed 37 endoleaks in 30 of 53 studies (56.6%). Session B revealed 31 of the 37 endoleaks, with one false-positive case, 83.8% sensitivity, 95.8% specificity, 79.3% negative predictive value, and 96.9% positive predictive value. Session C correctly depicted all 37 endoleaks, with one false-positive case, 100% sensitivity, 95.8% specificity, 100% negative predictive value, and 97.4% positive predictive value. Underestimation of false lumen patency was found in session B (P = .013). Virtual noncontrast imaging resulted in 17% radiation exposure reduction. ConclusionsVirtual noncontrast imaging can replace standard unenhanced images in follow-up after TEVAR of type B dissection, thus reducing radiation dose. Delayed-phase imaging is valuable in low-flow endoleaks detection and false lumen patency assessment.

Midterm Results of Intentional Celiac Artery Coverage During TEVAR for Type B Aortic Dissection

To report the outcome of intended celiac artery coverage during thoracic endovascular aortic repair (TEVAR) for type B aortic dissection with an intimal tear near the celiac artery (CA) orifice. Between 2007 and 2011, 13 patients (10 men; mean age 61.3 years, range 46-70) with type B aortic dissection underwent primary (n=9) or secondary (n=4) TEVAR with intentional CA coverage. Preoperative imaging was performed to confirm the existence of collateral circulation between the celiac artery and superior mesenteric artery. A short stent-graft was then deployed to cover both the entry tear and the CA. Follow-up was at 2 weeks; 1, 3, and 6 months; and every year thereafter. Preoperative diameters of the true and false lumens at the CA level, 8 cm above the CA, and at the aortic bifurcation, along with the maximum aortic diameter in the dissected segment, were compared to similar measurements at 6 months. All stent-graft procedures were successful and without complication. No immediate or delayed endoleak was identified in 8 of 13 patients over a mean 25-month follow-up (range 3-38). The other 5 patients had type II endoleak on completion imaging; these all resolved within 3 months after operation. Postoperative blood liver function and amylase assays were normal in all patients. No abdominal symptoms or signs of spinal cord ischemia were discovered. Expansion of the true lumen after TEVAR was statistically significant vs. at baseline in both groups (primary p<0.001, secondary p=0.023). Both the false lumen and the entire aorta showed signs of shrinkage after TEVAR in the 2 groups as well, although only the secondary group showed significant change (p<0.005) vs. baseline. TEVAR with intentional CA coverage is effective in excluding an infradiaphragmatic entry tear near the CA level. The incidence of abdominal ischemia is low if collateral circulation has been confirmed preoperatively. Type II endoleak is a major complication, yet most cease under observation.

Midterm Results for Endovascular Repair of Complicated Acute and Chronic Type B Aortic Dissection

Thoracic endovascular aortic repair (TEVAR) for the management of type B aortic dissections has become more commonplace despite some controversy. Results of endovascular management of complicated acute (<2 weeks from symptom onset) and chronic (>2 weeks) type B aortic dissection with a view towards determining safety, efficacy, and requirement for secondary procedures are reviewed. Between June 2005 and November 2008, 55 patients (41 men) with a mean age of 59 +/- 12 years (range, 31 to 77 years) underwent TEVAR for the management of complicated acute (n = 22) or chronic (n = 33) type B dissection. Indications in acute dissection included impending or frank rupture in 11 and malperfusion syndromes in 11; the indication in chronic dissections was aneurysmal degeneration in 33. Primary technical success was 100%. In-hospital and 30-day rates of death, stroke, and permanent paraplegia/paresis were 2% (n = 1), 0%, and 2% (n = 1), respectively. Median follow-up was 7.1 months (range, 1 to 38 months). Overall actuarial midterm survival was 63% at 38 months, with an aorta-specific actuarial survival of 94%. Two patients (4%) required late conversion to open repair. Postoperative type I or III endoleak occurred in 3 (6%) and type II endoleak in 7 (15%). Two patients underwent subsequent endovascular occlusion. The composite reintervention rate in follow-up was 23.4% (n = 13). Endovascular repair for complicated acute and chronic type B dissection is safe and effective at early midterm follow-up. TEVAR for type B dissection requires more secondary interventions and imaging surveillance than conventional open reconstruction. Longer-term follow-up is needed to determine the durability of this approach.

Abstract 4274: Retrograde Ascending Aortic Dissection During or After Thoracic Aortic Stent-Graft Placement- Insights from the European Registry on EVAR Complications (EUREC)

Background: Thoracic endovascular aortic repair (TEVAR) is increasingly applied in the treatment of aortic dissections and aneurysms. Single center reports have addressed retrograde ascending aortic dissection (rAAD) as a potentially lethal complication unique to TEVAR. We used data from a European multi-center registry to determine possible etiological factors and outcomes of this dreadful complication. Methods: So far 15 European sites and 1 Chinese center are contributing to the European Registry on EVAR Complications (EUREC) which is an open, independent, ongoing multi-center registry. Between 01/1998 and 05/2008 these centers performed a total of 3074 TEVAR procedures. Results: 33 rAAD cases (56.3±11.6 yrs, 20 males) were reported (incidence 1.1%). Indications for TEVAR were: acute type B dissection (n=17), chronic dissection (n=10), thoracic aneurysm (n=4), and aortic ulcer (n=1). 20 procedures were performed as emergency TEVAR. Stent-grafts with proximal bare springs were used in 26/33 (79%) cases. Additional balloon inflations were performed in 6 (18%) cases. rAAD occurred intraoperatively (n=5, 15%), during the index hospitalization (n=7, 21%), and during follow-up (n=21, 64%). 9 (27%) patients were asymptomatic, the remaining patients presented with acute chest pain (n=11, 33%), syncope (n=10, 30%), or sudden death (n=5, 15%). Emergency or elective surgical repair was performed in 19 and 4 patients, respectively. Conservative therapy was chosen in the remaining 10 patients. Outcome was fatal in 14/33 (42%) patients. The most probable cause of rAAD as reported by the investigators was stent-graft induced in 58%, procedure related in 9%, and underlying undiagnosed aortic disease in 15% of patients. In 16/33 patients direct evidence of stent-graft induced rAAD was obtained by surgery or necropsy. Conclusion: Although the incidence of rAAD was low (1.1%) in the present EUREC analysis, it was associated with significant mortality (42%). Patients undergoing TEVAR for type B dissection appeared to be most prone rAAD. As suspected, the majority of rAAD cases was associated with the use of proximal bare spring stent-grafts and in almost half of the patients direct evidence of stent-graft induced injury was obtained from surgery or necropsy.