Novel insights into thoracic endografts technology for prevention of distal stent-graft induced new entry (dSINE) following endovascular repair of type B aortic dissections: from bench to bedside

INTRODUCTION

Endovascular treatment of type B aortic dissections (TBAD) has currently acquired a primary therapeutic role when anatomically feasible. The main issue with thoracic endovascular aortic repair (TEVAR) for aortic dissection is the actual nature of the aortic wall, which is structurally compromised and more fragile. Indeed, a wealth of data have shown that TEVAR for TBAD will lead, in a substantial proportion of cases, to a device-related adverse event named distal stent-graft induced new entry (dSINE).

AREAS COVERED

Currently available aortic stent-grafts have not been specifically devised for the treatment of aortic dissection. A novel dissection specific stent-graft (DSSG) was developed, which is a custom-made device based on the Zenith Alpha Thoracic platform (Cook Medical). The DSSG has several unique properties that, in principle, make its use optimal in TBAD patients.

EXPERT OPINION

TEVAR in the setting of aortic dissections remains technically challenging. The occurrence of dSINE represents a unique complication in this scenario and may lead to high rates of aortic-related adverse events and need for secondary interventions. The use of a novel custom-made DSSG in the setting of chronic TBAD has been proven to be safe, feasible and effective. However, even this approach may fail to completely prevent dSINE formation.

Outcomes After Endovascular Aortic Intervention in Patients With Connective Tissue Disease

Importance

Endovascular treatment is not recommended for aortic pathologies in patients with connective tissue diseases (CTDs) other than in redo operations and as bridging procedures in emergencies. However, recent developments in endovascular technology may challenge this dogma.

Objective

To assess the midterm outcomes of endovascular aortic repair in patients with CTD.

Design, Setting, and Participants

For this descriptive retrospective study, data on demographics, interventions, and short-term and midterm outcomes were collected from 18 aortic centers in Europe, Asia, North America, and New Zealand. Patients with CTD who had undergone endovascular aortic repair from 2005 to 2020 were included. Data were analyzed from December 2021 to November 2022.

Exposure

All principal endovascular aortic repairs, including redo surgery and complex repairs of the aortic arch and visceral aorta.

Main Outcomes and Measures

Short-term and midterm survival, rates of secondary procedures, and conversion to open repair.

Results

In total, 171 patients were included: 142 with Marfan syndrome, 17 with Loeys-Dietz syndrome, and 12 with vascular Ehlers-Danlos syndrome (vEDS). Median (IQR) age was 49.9 years (37.9-59.0), and 107 patients (62.6%) were male. One hundred fifty-two (88.9%) were treated for aortic dissections and 19 (11.1%) for degenerative aneurysms. One hundred thirty-six patients (79.5%) had undergone open aortic surgery before the index endovascular repair. In 74 patients (43.3%), arch and/or visceral branches were included in the repair. Primary technical success was achieved in 168 patients (98.2%), and 30-day mortality was 2.9% (5 patients). Survival at 1 and 5 years was 96.2% and 80.6% for Marfan syndrome, 93.8% and 85.2% for Loeys-Dietz syndrome, and 75.0% and 43.8% for vEDS, respectively. After a median (IQR) follow-up of 4.7 years (1.9-9.2), 91 patients (53.2%) had undergone secondary procedures, of which 14 (8.2%) were open conversions.

Conclusions and Relevance

This study found that endovascular aortic interventions, including redo procedures and complex repairs of the aortic arch and visceral aorta, in patients with CTD had a high rate of early technical success, low perioperative mortality, and a midterm survival rate comparable with reports of open aortic surgery in patients with CTD. The rate of secondary procedures was high, but few patients required conversion to open repair. Improvements in devices and techniques, as well as ongoing follow-up, may result in endovascular treatment for patients with CTD being included in guideline recommendations.

Iliac branch endoprosthesis for repair of a common iliac artery aneurysm in Loeys-Dietz syndrome type 3

The commercial availability of the iliac branch endoprosthesis (IBE) has permitted endovascular repair of iliac artery aneurysms with the preservation of pelvic circulation. However, the device instructions for use require certain anatomic criteria that can limit deployment in ≤30% of patients. Moreover, branched endovascular treatment of common iliac artery aneurysms with IBE in patients with connective tissue disorders such as Loeys-Dietz syndrome has not been described. In the present report, we have described our technique of alternative endograft aortoiliac reconstruction to overcome anatomic barriers to IBE placement in a patient with a giant common iliac artery aneurysm in the setting of a rare pathogenic variant in the SMAD3 gene.

Endovascular and Hybrid Repair in Patients with Heritable Thoracic Aortic Disease

OBJECTIVE

In individuals with heritable thoracic aortic disease (HTAD), endovascular repair for treatment of aortic aneurysm and dissection may be lifesaving but is associated with increased risk of failure of endovascular repair and adverse outcomes. This study reports our experience with early and late outcomes of endovascular aortic and branch vessel repair in patients with HTAD.

METHODS

A retrospective case series was performed by chart review of individuals with HTAD followed at Washington University School of Medicine/Barnes-Jewish Hospital who underwent endovascular aortic and/or branch vessel repair. Clinical features, imaging characteristics, and short- and long-term outcomes were collected.

RESULTS

Twenty-nine patients with HTAD (20 male; mean age 45 ± 13 years) underwent thirty-seven endovascular procedures between 2006 and 2020 with mean follow up of 54 ± 41 months. Seven patients underwent two or more separate endovascular procedures. Each procedure was considered separate for data collection and analysis. Underlying conditions included Marfan syndrome (n=16 procedures), Loeys-Dietz syndrome (n=14 procedures), vascular Ehlers-Danlos syndrome (n=3 procedures), and nonsyndromic HTAD (n=4 procedures). Twenty patients (69%) had prior open surgical aortic repair. Indications for endovascular aortic repair (n=31) included urgent repairs of acute complications of aortic dissection (n=10) or aneurysm rupture (n=3), and elective aortic repair (n=18; 10 chronic dissections and 8 chronic aneurysms). Six patients underwent elective endovascular repair of six branch vessel aneurysms or dissections. Six patients underwent hybrid open surgical and endovascular repair. Of the 37 procedures, twenty-five (68%) proximal landing zones were in the native aorta or branch vessel, eleven (30%) were in a surgical graft or elephant trunk and one was in a previously placed endograft. Thirty-six (97%) procedures were technically successful, and none required emergency surgical conversion. Two patients died: one from sepsis and one from presumed late pseudoaneurysm rupture, for a 5% per-procedure mortality rate. Two procedures were complicated by stroke and one patient developed paraparesis. Of the 31 aortic procedures, seven aortic endografts (23%) developed a stent-induced new entry (SINE) discovered with imaging at 20 ± 15 days post-procedure. Seven endografts (23%) developed a Type I endoleak and eight (26%) developed a Type II endoleak. No Type III endoleaks were seen. Within 30 days, two endografts (of 37, 5%) required reintervention. After 30 days, fifteen additional endografts (of 37, 41%) required reintervention. Two patients (of 6, 33%) who underwent hybrid repair required reintervention.

CONCLUSIONS

This study is the largest single-center case series examining outcomes of HTAD patients following endovascular repair. Urgent and elective endovascular repairs in patients with HTAD can manage acute and chronic complications of aortic aneurysm and dissection with relatively low risk. However, risk of early and late endoleaks and SINE is high. Close post-procedural surveillance is required, and many individuals will require additional interventions. Hybrid repair shows promise and requires further investigation.

The PETTICOAT-snowshoe technique prevents distal stent graft-induced new entry in patients with aortic dissection

PURPOSE

Distal stent graft-induced new entry (SINE) is a serious complication of thoracic endovascular aortic repair (TEVAR) for Stanford type B aortic dissection (TBAD). The PETTICOAT-snowshoe technique was developed to prevent distal SINE for double-barrel TBAD. Initially, a proximal stent-graft (SG) is deployed, followed by the extension of a bare stent above the celiac artery and deployment of a second SG within the bare stent. This study examined whether the PETTICOAT-snowshoe technique prevents distal SINE.

MATERIALS AND METHODS

This was a single-center, retrospective study comparing two groups that underwent conventional standard TEVAR between January 2013 and September 2018 and TEVAR using the PETTICOAT-snowshoe technique after October 2018 for double-barrel TBAD.

RESULTS

Twenty-seven patients (74% male) underwent standard TEVAR (group A), while another 27 (78% male) underwent the PETTICOAT-snowshoe technique (group B). TEVAR was performed in the chronic phase on 15 patients (55.6%) in group A and on 16 (59.2%) in group B. Aorta-related mortality occurred in one patient in group A (3.7%). Oversizing ratios at the distal edge of the SG diameter to the major axis of the true lumen were 25% ± 26% and 25% ± 21% in groups A and B, respectively. During the follow-up period, five patients (18.5%) in group A and none in group B (p = 0.02) developed distal SINE. Three out of the five patients with distal SINE in group A were treated with additional TEVAR, one with thoracoabdominal aortic replacement, and one with conservative observation. The freedom from distal SINE rate was significantly higher in group B than in group A (p = 0.04).

CONCLUSIONS

The PETTICOAT-snowshoe technique significantly prevented distal SINE during the mid-term period even with the same distal SG oversizing as conventional standard TEVAR.

Endovascular Treatment of Aortic Pathologies in Patients With Marfan Syndrome: Single-Center Experience

OBJECTIVES

To study the outcome of endovascular treatment of aortic pathologies in patients with Marfan syndrome (MFS) at a single institution.

METHODS

Consecutive MFS patients who underwent endovascular repair or hybrid procedures for aortic pathologies from January 2010 to May 2020 were identified. Several endovascular and hybrid strategies have been used. Technical success, short- and mid-term survival, complications, and re-interventions were retrospectively analyzed.

RESULTS

During the study period, 24 patients with MFS (median age, 48 [13-78] years; 58% males) were treated. Indications for intervention were chronic aortic dissection with aneurysm degeneration in 16 patients (67%), acute type B aortic dissection in 4 patients (17%), aortic aneurysm without any dissection in 3 patients (13%), and aortic intramural hematoma in 1 patient (4%). Most patients were asymptomatic (83%), three (13%) were symptomatic and one (4%) had a contained rupture. The median aneurysm diameter was 56 (35-86) mm. Hybrid procedures were performed in 7 (29%) patients. Thoracic endovascular repair was performed in 12 (50%) patients, a fenestrated or branched endovascular aortic repair in 4 (17%) patients, and placement of an iliac artery stent-graft in 1 (4%) patient. Procedures were staged in 12 (50%) patients. Technical success was achieved in all patients. The median intensive care unit stay was 6 (range, 1-30) days, and the median hospital stay was 23 (range, 3-112) days. Early mortality was reported in 1 (4%) patient. Wound infection was seen in 7 (29%) patients and gastrointestinal complications in 3 (13%) patients. The median follow-up was 42 (range, 1-127) months. The cumulative survival rate was 87% at 24 months. The cumulative freedom from re-intervention was 77% at 12 months.

CONCLUSIONS

Endovascular treatment of aortic pathologies in patients with MFS appears feasible with acceptable early and mid-term outcomes in terms of mortality and re-intervention rates. Endovascular therapy plays an increasing role in MFS patients with aortic pathology.

Early experience with a novel dissection-specific stent-graft to prevent distal stent-graft-induced new entry tears after thoracic endovascular repair of chronic type B aortic dissections

PURPOSE

The aim was to report short and mid-term outcomes of a novel, investigational, dissection-specific stent-graft (DSSG), specifically designed to address the features of chronic type B aortic dissection (CTBAD) and reduce the risk of distal stent-graft-induced new entry tears (dSINE).

MATERIALS AND METHODS

A retrospective single center cohort study of all patients undergoing TEVAR with the DSSG for CTBAD from January 1, 2017 to January 31, 2020. The DSSG, which is a modified stent-graft based on the Cook Zenith Alpha Thoracic platform, has no proximal barbs and a customized longer body length with substantial taper. The second and third distal Z-stents are sited internally to avoid any contact of the metal skeleton with the dissection membrane and have reduced radial force, while the most distal stent was removed creating a distal 30 mm unsupported Dacron graft.

RESULTS

Sixteen patients (13 males, 3 females) with a median age of 66 years (range 31-79 years) underwent elective TEVAR of CTBAD using the DSSG. Six patients (38%) had an underlying connective tissue disorder. The median tapering was 10mm (range 4mm-21mm) and median length 270mm (range 210-380 mm). Technical success was achieved in all but one case (96%). One patient died within 30 days, due to retrograde type A dissection with cardiac tamponade. The 30-day rate of stroke, spinal cord ischemia and re-interventions was 0%. After median imaging follow-up time of 17 months (range 1 - 31 months), one patient developed a dSINE four months after the index procedure. After median survival follow-up of 23 months (range 2 - 35 months), one late death occurred due to traumatic brain injury, while no aortic-related death occurred during follow-up. Complete false lumen (FL) thrombosis was achieved in nine patients while the remaining six showed partial FL thrombosis. No instances of diameter increase at the level of treated aortic segment were noted with serial measurements showing either stable (n=7) or decreased (n=8) maximal transverse diameter.

CONCLUSIONS

Use of a novel DSSG with low radial force for TEVAR in the setting of CTBAD is safe and feasible. This early real-world experience shows promising mid-term effectiveness with low rates of dSINE or unplanned re-interventions and satisfactory aortic remodelling during follow-up. Longer follow-up is needed, however, before any firm conclusions can be drawn.

A S-Shaped Association of Distal Oversizing Ratio with Distal Stent-Graft-Induced New Entry Following Thoracic Endovascular Aortic Repair for Stanford B Aortic Dissection

BACKGROUND

This study was performed to evaluate the nonlinear association of the distal oversizing ratio with distal stent-graft-induced new entry (dSINE) following thoracic endovascular aortic repair (TEVAR) for type B aortic dissection (TBAD) and to find the optimal value of the distal oversizing ratio for prevention strategy of dSINE.

METHODS

Total of 177 patients who underwent TEVAR for TBAD from the Registry Of type B aortic dissection with the Utility of STent graft were retrospectively investigated. Patients were stratified into two groups on the median distal oversizing ratio: lower group (≤16%, n = 88) and higher group (>16%, n = 89). The Kaplan-Meier method was used to estimate the cumulative incidence of dSINE. The multivariate Cox proportional hazards model was used to identify the association of the distal oversizing ratio with dSINE. Restricted cubic smoothing spline plots and two-piecewise regression were used to analyze the possible nonlinear association.

RESULTS

Eleven patients developed dSINE (6.21%) during the median follow-up time of 12.37 months (interquartile range, 8.07-18.17 months). An S-shaped association of the distal oversizing ratio with dSINE was identified. When the distal oversizing ratio was ≤40%, the risk of dSINE increased with distal oversizing ratio, and the risk of dSINE was highest when the distal oversizing ratio reached 40% (adjusted HR, 1.09; 95% CI, 1.02-1.17; P = 0.011). A larger distal oversizing ratio over 40% did not generate a greater risk of dSINE (adjusted HR, 0.95; 95% CI, 0.87-1.05; P = 0.455).

CONCLUSIONS

This study substantiated previous findings that the dSINE was associated with the increasing distal oversizing ratio. We also found an S-shaped association between the distal oversizing ratio and dSINE after TEVAR for TBAD. The distal oversizing ratio of 40% can be used for stratified management of patients who underwent TEVAR for TBAD.

[Quo vadimus? Fundamental problems of developing hybrid prostheses of thoracic aorta]

This article is a review briefly characterizing the state of the art of hybrid surgery of the thoracic aorta using the frozen elephant trunk technique worldwide and in Russia, also discussing unsolved problems of fundamental science, being key issues in creation of new models of hybrid prostheses of the thoracic aorta. The main attention is paid to the problem of radial stiffness of the stent-graft portion of the prosthesis. Performed is a detailed analysis of the factors influencing this characteristic of the sent graft: shape, size and number of cells of the stent element, thickness of the nitinol wire it is made of, method of edge connection, nitinol properties depending on the alloy grade and methods of thermoforming. It is shown that excessive stiffness leads to the development of d-SINE syndrome. This is followed by discussing the problem of optimal stiffness of stent grafts, based on the design of stent graft elements and elastic properties of the wall of the true channel of a dissecting aortic aneurysm. Also proposed is an approach to solving the problem of d-SINE, consisting in creation of conical stent grafts and/or a gradual decrease of radial stiffness of stent elements in the direction of the distal portion. Comprehensively addressed are disadvantages of the graft portion of the prosthesis, in 95% of items made of polyethylene terephthalate fiber: susceptibility to degradation associated with manufacturing defects and intraoperative microdamages, abrasive effect in the zone of contact with stent elements, partial postoperative hydrolysis and an inflammatory reaction to a foreign body, often being clinically pronounced. Also touched upon are certain aspects of creating hermetic coatings of the graft portion, with the use of vancomycin possessing low cytotoxicity as part of an antibacterial component being promising. As a whole, it is demonstrated that advances in creating a novel generation of hybrid prostheses should be associated with new approaches and materials, to be obtained at the junction of medicine and fundamental sciences.

Endovascular treatment of chronic aortic dissection with fenestrated and branched stent grafts

OBJECTIVE

Chronic aortic dissection with aneurysm development that includes the aortic arch and/or thoracoabdominal aorta (TAAA) is traditionally treated with open or hybrid surgery. Total endovascular treatment with fenestrated and branched aortic repair (F/B-EVAR) has recently been introduced as a less invasive alternative. The aim was to report the short- and midterm outcomes from a single tertiary vascular center.

METHODS

All patients with chronic aortic dissection treated with F/B-EVAR from 2010 to 2019 at Uppsala University Hospital were identified. Perioperative and postoperative parameters were analyzed, with focus on short- (<30 days) and midterm survival, complication, and reintervention rates.

RESULTS

F/B-EVAR was performed on 26 patients (median age, 63 years; range, 33-87 years; 18 men; median aortic diameter, 70 mm; range, 50-98 mm); with a median follow-up of 23 months (range, 0.5-118.0 months). One patient underwent both arch and TAAA repair. Overall, 13 arch repairs (arch group) after type A (n = 8) and type B (n = 5) dissection (all elective) were performed, and 14 TAAA repairs (TAAA group) after type A (n = 5) and type B (n = 9) dissection (one rupture). A total of 72 aortic branches were targeted (22 arch, 50 TAAA). Short-term technical success was achieved in 24 of 27 procedures (89%). Failures were related to one intraoperative retrograde type A dissection (RTAD) requiring open conversion (arch group), one persistent type IC endoleak on completion angiography (arch group), and one persistent type III endoleak (TAAA group). Mortality was 4% (n = 1) at 30 days and related to a second RTAD that occurred after discharge and was found on autopsy. Both RTADs occurred in patients with chronic type B dissection undergoing fenestrated arch repair. Paraplegia occurred in three cases (two arch, one TAAA) (11%), none permanent, and stroke in three cases (one arch, one TAAA) (11%); one was permanent. In the midterm, endoleaks were detected in 12 patients (44%); persistent false lumen flow (n = 3), type IB (n = 1), type IC (n = 3), type II (n = 7), and type IIIC (n = 2). The 3-year survival (Kaplan-Meier) of the arch repair was 75% and for the TAAA, 93%. Freedom from reintervention at 3 years were 100% for arch repairs and 48% for TAAA. In patients with a follow-up of more than 6 months (n = 23), all had stable or decreased aortic diameters and complete false lumen thrombosis at the level of stent graft was present in 65% (n = 15).

CONCLUSIONS

Endovascular treatment of postdissection aneurysms is feasible, with acceptable short-term and midterm outcomes. RTAD after fenestrated and branched endovascular arch repair warrants caution when performed on patients with native ascending aortas, and reinterventions are frequent in TAAA repair.

Case-matched Comparison of Cardiovascular Outcome in Loeys-Dietz Syndrome versus Marfan Syndrome

Background: Pathogenic variants in TGFBR1, TGFBR2 and SMAD3 genes cause Loeys-Dietz syndrome, and pathogenic variants in FBN1 cause Marfan syndrome. Despite their similar phenotypes, both syndromes may have different cardiovascular outcomes. Methods: Three expert centers performed a case-matched comparison of cardiovascular outcomes. The Loeys-Dietz group comprised 43 men and 40 women with a mean age of 34 ± 18 years. Twenty-six individuals had pathogenic variants in TGFBR1, 40 in TGFBR2, and 17 in SMAD3. For case-matched comparison we used 83 age and sex-frequency matched individuals with Marfan syndrome. Results: In Loeys-Dietz compared to Marfan syndrome, a patent ductus arteriosus (p = 0.014) was more prevalent, the craniofacial score was higher (p < 0.001), the systemic score lower (p < 0.001), and mitral valve prolapse less frequent (p = 0.003). Mean survival for Loeys-Dietz and Marfan syndrome was similar (75 ± 3 versus 73 ± 2 years; p = 0.811). Cardiovascular outcome was comparable between Loeys-Dietz and Marfan syndrome, including mean freedom from proximal aortic surgery (53 ± 4 versus 48 ± 3 years; p = 0.589), distal aortic repair (72 ± 3 versus 67 ± 2 years; p = 0.777), mitral valve surgery (75 ± 4 versus 65 ± 3 years; p = 0.108), and reintervention (20 ± 3 versus 14 ± 2 years; p = 0.112). In Loeys-Dietz syndrome, lower age at initial presentation predicted proximal aortic surgery (HR = 0.748; p < 0.001), where receiver operating characteristic analysis identified ≤33.5 years with increased risk. In addition, increased aortic sinus diameters (HR = 6.502; p = 0.001), and higher systemic score points at least marginally (HR = 1.175; p = 0.065) related to proximal aortic surgery in Loeys-Dietz syndrome. Conclusions: Cardiovascular outcome of Loeys-Dietz syndrome was comparable to Marfan syndrome, but the severity of systemic manifestations was a predictor of proximal aortic surgery.