Restrictive bare stent for prevention of stent graft-induced distal redissection after thoracic endovascular aortic repair for type B aortic dissection

A Multicenter Study of the Mid-term Outcomes of Patients with Uncomplicated Type B Aortic Dissection After Distal Porous Talos Stent-Graft Implantation

BACKGROUND

The Talos stent-graft has extended length to improve aortic remodeling, and distal porous design to decrease the rate of spinal cord ischemia (SCI). This study retrospectively analyzed its mid-term outcomes for uncomplicated type B aortic dissection in a multicenter study.

METHODS

The primary safety end point was 30-day major adverse events, including all-cause mortality, dissection-related mortality, conversion to open surgery, and device-related adverse events. The primary efficacy end point was treatment success at 12 months postoperation, defined as no technical failure or secondary dissection-related reintervention. The survival status of the patients was visualized using the Kaplan-Meier curve. Aortic growth was assessed at 4 levels, and SCI was evaluated at 12 months.

RESULTS

113 patients participated with a mean age of 54.4 (11.1) years and 71.7% (81/113) were male. The 30-day mortality was 0.9% (1/113), no conversions to open surgery or device-related adverse events were recorded. The 12-month treatment success rate was 99.1% (112/113), with no dissection-related reinterventions. There was no spinal cord or visceral ischemia at 12 months. At a median of 34 months follow-up, 9 further deaths were recorded and the 3-year survival rate was 91.7%. The percentage of aortic growth was 1.8% (2/111) at the tracheal bifurcation, 3.6% (4/111) below the left atrium, 6.0% (5/83) above the celiac artery, and 12.1% (9/74) below the lower renal artery. The total thrombosis rate of the false lumen at the stented segment was 80.5% (91/113).

CONCLUSIONS

The results showed satisfactory results of Talos stent-graft in terms of safety and efficacy. More data are needed to confirm the long-term performance.

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.

Prevention of distal stent graft-induced new entry after endovascular repair for type B aortic dissection: A retrospective cohort study

OBJECTIVES

Distal stent graft-induced new entry (dSINE) can occur after thoracic endovascular aortic repair (TEVAR) for type B aortic dissection (TBAD). In this study we aimed to compare the effectiveness of restrictive bare stent (RBS), tapered stent graft (TSG), and non-TSG in TEVAR in preventing dSINE after a midterm follow-up.

METHODS

This retrospective cohort study included patients with TBAD who underwent TEVAR (June 2010 to December 2018). The occurrence of dSINE during follow-up was examined. Predictors of dSINE were determined using Fine-Gray regression with death as the competing event. Survival was evaluated using Cox proportional hazards regression.

RESULTS

Finally, 364 patients were included: 111 with non-TSG TEVAR, 125 with TSG TEVAR, and 128 with TEVAR with RBS. After 54.5 months, incidences of dSINE in the 3 groups were 12.61%, 4.80%, and 1.56%, respectively (P = .002). On Fine-Gray regression adjusted for clinically relevant covariates, the expansion mismatch ratio (subdistribution hazard ratio, 1.09; 95% CI, 1.07-1.12; P < .001) and complete false lumen thrombosis (subdistribution hazard ratio, 0.35; 95% CI, 0.13-0.94; P = .037) were identified as predictors of dSINE. The Cox proportional hazards regression analysis revealed that dSINE was not only a risk factor for aortic-related mortality (hazard ratio, 17.90; 95% CI, 3.27-98.12; P = .001), but also a predominant risk factor for all-cause mortality (hazard ratio, 4.91; 95% CI, 1.66-14.52; P = .004).

CONCLUSIONS

dSINE can happen in TBAD patients who undergo TEVAR. Thus, long-term surveillance is crucial. TSG and RBS had lower expansion mismatch ratios, which might help prevent dSINE.

A CT-based predictive model for stent-induced vessel damage: application to type B aortic dissection

OBJECTIVES

The distal stent-induced new entry (distal SINE) is a life-threatening device-related complication after thoracic endovascular aortic repair (TEVAR). However, risk factors for distal SINE are not fully determined, and prediction models are lacking. This study aimed to establish a predictive model for distal SINE based on the preoperative dataset.

METHODS

Two hundred and six patients with Stanford type B aortic dissection (TBAD) that experienced TEVAR were involved in this study. Among them, thirty patients developed distal SINE. Pre-TEVAR morphological parameters were measured based on the CT-reconstructed configurations. Virtual post-TEVAR morphological and mechanical parameters were computed via the virtual stenting algorithm (VSA). Two predictive models (PM-1 and PM-2) were developed and presented as nomograms to help risk evaluation of distal SINE. The performance of the proposed predictive models was evaluated and internal validation was conducted.

RESULTS

Machine-selected variables for PM-1 included key pre-TEVAR parameters, and those for PM-2 included key virtual post-TEVAR parameters. Both models showed good calibration in both development and validation subsamples, while PM-2 outperformed PM-1. The discrimination of PM-2 was better than PM-1 in the development subsample, with an optimism-corrected area under the curve (AUC) of 0.95 and 0.77, respectively. Application of PM-2 in the validation subsample presented good discrimination with an AUC of 0.9727. The decision curve demonstrated that PM-2 was clinically useful.

CONCLUSION

This study proposed a predictive model for distal SINE incorporating the CT-based VSA. This predictive model could efficiently predict the risk of distal SINE and thus might contribute to personalized intervention planning.

CLINICAL RELEVANCE STATEMENT

This study established a predictive model to evaluate the risk of distal SINE based on the pre-stenting CT dataset and planned device information. With an accurate VSA tool, the predictive model could help to improve the safety of the endovascular repair procedure.

KEY POINTS

• Clinically useful prediction models for distal stent-induced new entry are still lacking, and the safety of the stent implantation is hard to guarantee. • Our proposed predictive tool based on a virtual stenting algorithm supports different stenting planning rehearsals and real-time risk evaluation, guiding clinicians to optimize the presurgical plan when necessary. • The established prediction model provides accurate risk evaluation for vessel damage, improving the safety of the intervention procedure.

Prognosis and Remodeling after Endovascular Repair for Acute, Subacute, and Chronic Type B Aortic Dissection

PURPOSE

Thoracic endovascular aortic repair (TEVAR) for type B aortic dissection (TBAD) is already well introduced, but the best time point to perform TEVAR has not been defined. This study was to report mid- to long-term outcomes and aortic remodeling of TEVAR in patients with TBAD.

MATERIALS AND METHODS

In total, 318 TBAD patients from June 2001 to May 2016 were retrospectively reviewed. Patients were divided into 3 groups depending on interval between dissection onset to TEVAR: acute (0-7 days), subacute (8-30 days), and chronic (>30 days). Clinical and morphological data were collected and analyzed.

RESULTS

The follow-up aorta-related mortality rates in the 3 groups were 17.6%, 2.6%, 4.2%, and the proximal stent-induced new entry rates were 11.8%, 1.6%, 2.8%, respectively. Aortic remodeling was satisfied in both the acute and subacute group, but the false lumen diameter did not decrease (p>0.05) in the chronic group. Compared with the VIRTUE classification (acute, 0-14 days; subacute, 15-92 days; chronic, >92 days), mid- to long-term outcomes of patients within the first overlapped interval between the 2 classifications (8-14 days) were similar to that of subacute patients (15-30 days), while aortic remodeling of patients in the second overlapped interval (31-92 days) was similar to that of chronic patients (>92 days).

CONCLUSIONS

This study suggests that TEVAR for subacute TBAD is associated with a low long-term rate of aorta-related death. Aortic remodeling of chronic dissections is not satisfactory. Additional results suggest that the subacute phase (8-30 days) may be the optimal time to perform TEVAR for uncomplicated TBAD.

A machine learning approach for predicting descending thoracic aortic diameter

Background

To establish models for predicting descending thoracic aortic diameters and provide evidence for selecting the size of the stent graft for TBAD patients.

Methods

A total of 200 candidates without severe deformation of aorta were included. CTA information was collected and 3D reconstructed. In the reconstructed CTA, a total of 12 cross-sections of peripheral vessels were made perpendicular to the axis of flow of the aorta. Parameters of the cross sections and basic clinical characteristics were used for prediction. The data was randomly split into the training set and the test set in an 8:2 ratio. To fully describe diameters of descending thoracic aorta, three predicted points were set based quadrisection, and a total of 12 models at three predicted points were established using four algorithms included linear regression (LR), support vector machine (SVM), Extra-Tree regression (ETR) and random forest regression (RFR). The performance of models was evaluated by mean square error (MSE) of the prediction value, and the ranking of feature importance was given by Shapley value. After modeling, prognosis of five TEVAR cases and stent oversizing were compared.

Results

We identified a series of parameters which affect the diameter of descending thoracic aorta, including age, hypertension, the area of proximal edge of superior mesenteric artery, etc. Among four predictive models, all the MSEs of SVM models at three different predicted position were less than 2 mm², with approximately 90% predicted diameters error less than 2 mm in the test sets. In patients with dSINE, stent oversizing was about 3 mm, while only 1 mm in patients without complications.

Conclusion

The predictive models established by machine learning revealed the relationship between basic characteristics and diameters of different segment of descending aorta, which help to provide evidence for selecting the matching distal size of the stent for TBAD patients, thereby reducing the incidence of TEVAR complications.

False lumen patency status and outcomes after endovascular repair of uncomplicated chronic type B dissection

BACKGROUND

Thoracic endovascular aortic repair (TEVAR) remains a controversial treatment for uncomplicated chronic type B aortic dissection (cTBAD). This study was performed to investigate the postoperative outcomes of TEVAR, such as survival and reintervention, and the risk factors for prognoses.

METHODS

In total, 41 patients with uncomplicated cTBAD who underwent TEVAR from 2014 to 2021 were reviewed. The patients were divided into two groups: those with false lumen complete thrombosis (FLCT) and false lumen partial thrombosis (FLPT) based on computed tomography angiography (CTA) images. Kaplan-Meier analysis was performed to estimate survival and freedom from reintervention. Binary logistic analysis was performed to estimate risk factors for partial thrombosis.

RESULTS

During a mean follow-up of 31 (1-78) months, five deaths and six reinterventions had occurred at 5 years. By 1 week, thoracic FLCT had occurred in 23 (56.1%) patients and thoracic FLPT had occurred in 18 (43.9%). The rate of freedom from reintervention was significantly lower in the FLCT than in the FLPT group (p = 0.04). The 5-year survival rate of the two groups was not statistically significant (p = 0.14). Risk factors for thoracic FLPT were the distance between the re-entry site and the graft (p = 0.02) and the proximal oversizing ratio (p = 0.04).

CONCLUSIONS

TEVAR is an effective and safe treatment for uncomplicated cTBAD and has a low mortality rate. Thoracic FLCT is associated with less reintervention, but overall survival is not impacted by this difference. Patients treated with TEVAR without certain risk factors can have a good prognosis.

Thoracic endovascular aortic repair of highly tapered type B aortic dissection with proximal tapered stent grafts and distal restrictive stent grafts

OBJECTIVES

This study evaluated aortic remodeling in highly tapered type B aortic dissection (TBAD) patients who underwent thoracic endovascular aortic repair (TEVAR) with a proximal tapered stent graft plus a distal restrictive stent graft to maximize thoracic coverage while avoiding distal excessive oversizing.

METHODS

Thirty-four patients presenting with highly tapered TABD were randomized to restricted TEVAR (r-TEVAR) and standard TEVAR groups. Highly tapered TBAD was defined as the maximal diameter of the true lumen at proximal and distal thoracic aorta landing zone tapers greater than 8 mm or taper ratio greater than 20%. Patients in the r-TEVAR group underwent proximal tapered stent grafts plus distal restrictive stent grafts to match the taper ratio of the descending thoracic aorta (DTA) and extend the length of stent coverage. Patients in the standard TEVAR group underwent proximal tapered stent grafts implantation without distal restrictive stent grafts. Aortic remodeling was estimated by computed tomography angiography (CTA) during the follow-up.

RESULTS

In total, 16 patients underwent r-TEVAR, and 18 patients underwent standard TEVAR. The taper ratio of the stent graft matched the DTA in the r-TEVAR group (24.7±3.4% vs. 27.3±4.2%, P=0.068) but did not match that in the standard TEVAR group (13.5±3.3% vs. 30.5±9.6%, P<0.001). The length of stent graft coverage in the r-TEVAR group was longer than that in the standard TEVAR group (220.4±21.1 mm vs. 175.3±17.8 mm, P<0.001). Compared with the standard TEVAR group, the r-TEVAR group had better complete remodeling of the DTA at 6 months (40% vs. 5.6%, P=0.03), 12 months (60% vs. 16.7%, P=0.027) and 24 months (78.6% vs. 41.2%, P=0.036) after the operation. There was no difference in the cumulative survival rate between the r-TEVAR and standard TEVAR groups (P=0.166).

CONCLUSIONS

r-TEVAR with overlapping proximal tapered stent grafts and distal restrictive stent grafts can match the taper of highly tapered TABD, extend the length of stent graft coverage, and lead to better remodeling of the DTA than standard TEVAR.

A new dissection-specific hybrid stent graft for patients with DeBakey type I aortic dissection

OBJECTIVES

We present our first experience of using a new dissection-specific hybrid stent graft (SG) (the 'Soft Elephant Trunk') in the frozen elephant trunk technique, in patients with non-acute DeBakey type I aortic dissection.

METHODS

Between September 2016 and February 2021, patients with non-acute DeBakey type I aortic dissection underwent the frozen elephant trunk procedure at our centre using 3 SG types: group Z used stiff, distal Z-shaped nitinol SGs (E-Vita, Medtronic); group R used a stiff, ring-shaped nitinol SG (Thoraflex); and group S used a soft, distal dissection-specific SG. Predictors of distal SG-induced new entry were analysed. End points were hospital- and midterm-follow-up results.

RESULTS

The study comprised 109 patients with 46 (42.2%), 22 (20.2%) and 41 (37.6%) patients in groups Z, R and S, respectively. No significant differences were found in early outcomes. Freedom from distal SG-induced new entry was comparable in groups Z, R and S (68.9% vs 92.9% vs 100%, log-rank = 0.14). There was no significant difference in follow-up between the groups. Four-year survival rates were 80.44%, 71.59% and 95.06% in groups Z, R and S, respectively. On multivariable analysis, the presence of connective tissue disorders [hazard ratio (HR) = 5.62, P = 0.11] and SG diameter (HR = 1.37, P = 0.034) were strong predictors of distal SG-induced new entry.

CONCLUSIONS

Dissection-specific hybrid SG with a soft distal end is effective in patients with non-acute DeBakey type I aortic dissection. Compared to non-soft distal SGs, this can reduce the incidence of distal complications. Long-term outcomes are necessary to determine the potential advantages and disadvantages of the new prosthesis.

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.

Midterm outcomes of fenestrated TEVAR using physician-modified endovascular grafts for zone 2

OBJECTIVES

To summarize the experience and midterm outcomes of physician-modified endovascular grafts for zone 2 thoracic endovascular aortic repair.

METHODS

A retrospective analysis was conducted of 51 consecutive patients (mean age 57.6 ± 12.5 years, 39 males) treated with thoracic endovascular aortic repair using physician-modified endovascular grafts for reconstructing the left subclavian artery from November 2015 to December 2019. The primary endpoints during follow-up were the overall mortality, aorta-related mortality, and major complications. The secondary endpoints were reintervention and the patency of the target branches, the demographics and technical details were also described and analyzed.

RESULTS

Sixty-three thoracic stent-grafts were deployed in 51 patients and emergency surgery was performed in 10 patients (19.6%). Technical success was 94.1% (48/51). The incidence of perioperative complications was 15.7%, and the 30-day mortality was 0%. At a mean follow-up of 42.0 ± 14.4 months (range, 14-63 months), all the left subclavian arteries remained patent. All-cause mortality was 3.9% (2/51) and not aorta-related deaths. Estimated survival at one and three years was 98.0 ± 1.9% and 96.0 ± 2.8%, respectively.

CONCLUSIONS

The physician-modified endovascular grafts is feasible and effective to preserve left subclavian artery in thoracic endovascular aortic repair for aortic arch pathologies with unhealthy proximal landing zone.

Clinical Outcomes of Distal Tapered Restrictive Covered Stent Applied in Endovascular Treatment of Aortic Dissection Involving Zone 0

OBJECTIVE

The safety and efficacy of a distal tapered restrictive covered stent (RCS) applied in the endovascular treatment of aortic dissection involving Zone 0 was evaluated.

METHODS

This study retrospectively analysed 43 patients with acute aortic dissection involving Zone 0 who received in situ laser fenestrated thoracic endovascular aortic repair with distal tapered RCS from January 2015 to February 2019. The indication for the distal tapered RCS procedure was an inappropriate distal size of the main stent graft. Technical success, aortic remodelling, and clinical outcomes were evaluated.

RESULTS

Technical success was achieved in all patients. The 30 day post-operative mortality rate was 0%. All patients had complete false lumen thrombosis in the stent coverage segment. True lumen volume increased significantly (p < .001) with an average change of 87.0% ± 34.3%, while false lumen volume decreased significantly (p < .001) with an average change of -71.0% ± 13.5% between baseline and 12 months. During the follow up period (mean 28.7 months, range 12-63 months), no distal stent graft induced new entry (SINE) was observed. The average distance between the distal end of the RCS and the coeliac trunk was 57.5 mm. Two (4.7%) patients had spinal cord ischaemia (SCI) and recovered without permanent paraplegia after undergoing conservative treatment.

CONCLUSION

The distal tapered RCS applied in the endovascular treatment of aortic dissection involving Zone 0 is considered to be a feasible and effective approach along with satisfactory aortic remodelling, a low risk of SINE, and SCI. The favourable results are partly explained by selection. No patients had an entry tear near the coronary artery, nor were the coronary arteries, pericardium, or aortic valve involved at the time of repair.

Distal bare metal stent implantation during thoracic endovascular aortic repair is beneficial to treat complicated type B aortic dissection: A systematic review and meta-analysis

OBJECTIVE

To explore whether thoracic endovascular aortic repair (TEVAR) plus distal bare metal stent (BMS) implantation leads to favorable clinical outcomes compared with standard TEVAR in treating acute complicated type B aortic dissection.

METHODS

Relevant publications were found through a precise search of PubMed, Cochrane Library, and EMBASE. Count data were calculated as the odd ratio (OR)and 95% confidence interval (CI) using the Mantel-Haenszel statistical method, quantitative data were calculated as mean difference and 95% CI using Inverse Variance statistical method. When the data heterogeneity was large, with an I² > 50%, a random-effects model and sensitivity analysis were performed. The analysis tool we used was the software Revman 5.3 and G*power 3.1.

RESULTS

There were 7 publications involving 958 patients who were enrolled ultimately. The incidence of unplanned secondary intervention and postoperative adverse events in the TEVAR + BMS were lower than standard TEVAR (OR, 0.42, (95% CI, 0.23 to 0.75); OR, 0.57, (95% CI, 0.37 to 0.90)), and the pooled number needed to treat was 15 for unplanned secondary intervention and 15 for postoperative adverse events. There were no significant difference in the aortic-related or all-cause 30-day mortality (OR, 0.81, (95% CI, 0.25 to 2.61); OR, 0.47, (95% CI, 0.18 to 1.22)), aortic-related, all-cause mortality at least 6 months or incidence of the postoperative endoleak (OR, 0.47, (95% CI, 0.17 to 1.32); OR, 0.42, (95% CI, 0.17 to 1.06); OR, 0.81, (95% CI, 0.32 to 2.05)).

CONCLUSION

There is no significant outcome difference except for reduced reintervention but this does not seem to adversely affect survival. It is unclear whether this justifies the additional cost of placing it in every complicated type B aortic dissection regardless of anatomy after standard TEVAR alone. Besides, more data are needed to verify the adjunctive distal bare metal stents' performance at different dissection stages.

A 10-year study of surgical results of descending aorta aneurysm repair following chronic aortic dissection

BACKGROUND

Patients presenting with descending aortic aneurysms developing after aortic dissection often undergo continued aortic expansion which may require operative interventions to address the risk of aortic rupture. In light of the current advances in various treatment options, including endovascular approaches, we analyzed our experience with open surgical repair (OSR) of aneurysms of the descending aorta following aortic dissection.

METHODS

Patients who underwent open repair for aneurysmal changes of the descending aorta after chronic dissection were retrospectively studied. The 30-day operative mortality rate, midterm survival, and major complications were analyzed. Patients were divided into two categories; primary chronic type B aortic dissection and remnant repaired type A aortic dissection (RTAAD).

RESULTS

There were 149 patients with enlargement of the descending thoracic aorta developing after aortic dissection. Of these, 49 patients had medical management, while the remaining 100 patients received OSR. These patients were included in the present analysis. The 30-day mortality and permanent paraplegia rates were 9% and 4%, respectively. The 1-, 3-, and 5-year survival rates were 83%, 80.9%, and 76.1%, respectively. The 1- and 5-year survival rates between the primary chronic type B aortic dissection and remnant RTAAD groups showed no significant between-group differences at 86.7% and 84.3%, and 80% and 71.3%, respectively (P = .289). The overall outcomes of other complications such as renal injury, bleeding reoperation, and extracorporeal membrane oxygenation support showed no significant between-group differences, including an insignificantly higher neurologic complication rate in the remnant RTAAD group. The survival rate in patients with Marfan syndrome was significantly higher than in the patients without Marfan syndrome (P = .033).

CONCLUSIONS

OSR for descending aortic aneurysms developing after chronic aortic dissection showed good early and mid- to long-term outcomes, with acceptably low complication rates. OSR for descending aortic aneurysm after chronic aortic dissection associated with Marfan syndrome also showed good early and mid- to long-term outcomes.

A meta-analysis of combined proximal stent grafting with or without adjunctive distal bare stent for the management of aortic dissection

BACKGROUND

The efficacy and safety of placement of a proximal covered stent graft combined with a distal bare stent are controversial because of the lack of evidence. This systematic review and meta-analysis compared the outcomes of combined proximal covered stent grafting with distal bare stenting (BS group) and proximal covered stent grafting without distal bare stenting (non-BS group).

METHODS

The MEDLINE, Embase, and Cochrane Central Register of Controlled Trials databases and key references were searched up to January 26, 2019. Predefined outcomes of interest were mortality, morbidity, and postoperative assessment of aortic remodeling. We pooled risk ratios (RRs) of the outcomes of interest using fixed effects model or random effects model.

RESULTS

Overall, eight observational studies involving 914 patients were included. There were no significant differences in overall aorta-related mortality (RR, 0.54; confidence interval [CI], 0.24-1.24; P = .15), complete thoracic false lumen (FL) thrombosis rate (RR, 1.23; CI, 0.83-1.81; P = .30), or complete abdominal FL thrombosis rate (RR, 1.96; CI, 0.68-5.69; P = .21) between the BS group and the non-BS group. The BS group had a lower rate of partial thoracic FL thrombosis (RR, 0.40; CI, 0.25-0.65; P = .0002), a lower stent graft-induced new entry rate (RR, 0.08; CI, 0.02-0.41; P = .003), and a lower reintervention rate (RR, 0.42; CI, 0.26-0.69; P = .0005).

CONCLUSIONS

Combined proximal covered stent grafting with distal adjunctive bare stenting had the potential to reduce the partial thoracic FL thrombosis rate and the rates of stent graft-induced new entry and reintervention but was not associated with lower aorta-related mortality or the complete FL thrombosis rate. Further research with a stricter methodology is needed.

Surgical Outcomes And Postoperative Descending Aorta Morphologic Remodeling After Thoracic Endovascular Aortic Repair For Acute And Chronic Type B Aortic Dissection

Background

This study aims to investigate the descending aortic morphological alterations caused by pathological changes in acute and chronic Type B aortic dissection (TBAD) and morphological remodeling after thoracic endovascular aortic repair (TEVAR).

Patients and methods

From February 2012 to January 2016, 86 TBAD patients undergoing TEVAR were divided into an acute group (n=63) and a chronic group (n=23). The areas of the true, false and maximal lumen and descending aorta morphological parameters, including the taper ratio (TR), oversizing ratio (OR), mismatch ratio (MR), radius of curvature (RoC) and tortuosity index (TI), were evaluated. Follow-ups were performed postoperatively before discharge, at 1 and 6 months, and yearly thereafter.

Results

Before TEVAR, the TR (0.57 (0.49) vs 0.74 (0.60); P < 0.05), OR (2.75 ± 1.89 vs 3.96 ± 2.27; P < 0.05) and TI (1.22 (1.19) vs 1.41 ± 0.17; P < 0.05) were significantly higher in the chronic group than in the acute group. The TEVAR technical success rate was 100%. No differences were found in 30-day and >30-day mortality between the two groups. Pathology-specific devices, such as tapered stent grafts and distal bare stents, were used more frequently in the chronic group than in the acute group (47.8% vs 23.8%, P = 0.03; 43.5% vs 12.7%, P = 0.002, respectively). The OR and TI changes that occurred after TEVAR were significantly higher in the chronic group than in the acute group (1.80 ± 0.86 vs 2.98 ± 1.85, P = 0.028; 0.00 ± 0.09 vs 0.09 ± 0.10, P < 0.001, respectively).

Conclusion

TEVAR is a safe and effective therapy for acute and chronic TBAD. Compared to acute TBAD, chronic TBAD resulted in an adverse preoperative descending aorta morphology. Pathology-specific devices may be a feasible treatment option for endovascular repair of chronic TBAD. A larger series of cases with longer follow-up are needed to draw definitive conclusions.

Aortic remodeling in Type B aortic dissection after thoracic endovascular aortic repair with an aortic extender cuff implantation

Objective

This study investigated the safety and efficiency of thoracic endovascular aortic repair (TEVAR) plus an aortic extender cuff placement in treating Stanford Type B aortic dissections (TBADs).

Methods

Clinical data on 157 patients with TBADs who underwent TEVAR in two tertiary medical centers from February 2013 to March 2018 were analyzed retrospectively. An estimated mismatch rate >120% was the indication for placement of an aortic extender cuff. Results in the perioperative and follow-up periods (≥3 months) were analyzed, especially those of aortic remodeling.

Results

In total, 106 patients (67.5%) underwent standard TEVAR, and 51 (32.5%) received TEVAR plus an aortic extender cuff placement. The primary technical success rate was 96.8% (152/157). Perioperative adverse events included endoleak (2%, 3/157), spinal cord ischemia (SCI) (1.3%, 2/157), and transient renal failure (0.6%, 1/157), with no between-group differences. The median follow-up was 15 months (range 3–71 months). Ten cases of late stent complications were observed, including three endoleak, one upper limb ischemia, one stent distortion, and five stent graft-induced distal re-dissection (SIDR). Patients with a cuff had less distal re-dissection and fewer second interventions, but the differences lacked significance. In the last follow-up, the TEVAR+Cuff group were found to have better true lumen recovery and false lumen shrinkage, and increased complete false lumen thrombosis in the thoracic and abdominal segments; however, no statistical difference was evident in comparison with the TEVAR group (P>0.05).

Conclusion

TEVAR plus an aortic extender cuff implantation improves remodeling of the dissected thoracic aorta, thus reducing the potential of SIDR. Furthermore, the covered stent with a length of 250 mm does not increase the rate of SCI or paraplegia. However, these results should be confirmed in a larger series of patients with longer follow-up.

Endovascular repair of type B aortic dissection with the restrictive bare stent technique: morphologic changes, technique details, and outcomes

Purpose

The aim of this study was to present our experience and assess the morphologic changes of the descending aorta after the restrictive bare stent (RBS) technique in the treatment of type B aortic dissection (TBAD).

Patients and methods

A retrospective study was conducted of 22 consecutive patients with TBAD who underwent RBS treatment between February 2012 and June 2016. Indications for the RBS procedure included radiological evidence of true lumen (TL) compression or collapse and/or tortuosity index (TI) of the descending aorta >1.4. Technique success, descending aorta morphology, and clinical outcomes were evaluated.

Results

The technical success rate was 100%. Patients treated with the RBS technique were often accompanied by TL collapse (45.5%) or TI >1.4 (59.1%). One-month postoperative computed tomography angiography showed that the taper ratio, oversizing ratio of the stent graft, and TI values were significantly decreased compared with preoperative computed tomography angiography values (P<0.05). The 30-day mortality rate was 0%. In total 95.2% had a thrombosed false lumen in the segment of aortic coverage, and TL diameters were increased in 40.3%±11% (mean ± SD) and 37.5%±17.9% of patients in the thoracic and abdominal segments, respectively. During the follow-up from 16 to 64 months (33±19 months), no distal stent graft-induced new entry, endoleak, and paraplegia were observed. One patient died from rupture of a chronic TBAD with aneurysm degeneration.

Conclusion

Mid-term outcomes showed RBS to be a flexible and feasible approach to repair TBAD. RBS corrects the descending aorta morphology and promotes TL expansion in most patients, but the rupture of chronic TBAD with aneurysm degeneration was not prevented in all patients.

Is TEVAR with Full Petticoat Technique Effective for Complicated Acute Type B Dissection Cases?

Treatment by thoracic endovascular aortic repair (TEVAR) for type B dissection has improved outcomes. We tried the procedure named “Full Petticoat technique” in which the proximal entry tear was excluded with a covered stent and extended bare metal stents were placed to the aortic bifurcation for three complicated type B dissection cases with dynamic obstruction of the common iliac artery. Follow-up computed tomography revealed favorable aortic remodeling in which the true lumen was expanded. The short-term result of this procedure has shown acceptable aortic remodeling. The significance of this procedure is still unknown in the long term; hence long-term follow-up is necessary to completely understand the usefulness of this technique.

Contemporary Results of Endovascular Repair of Isolated Abdominal Aortic Dissection with Unibody Bifurcated Stent Grafts

OBJECTIVES

To report the midterm safety and efficacy of the Aegis™-B (Microport, Shanghai, China) unibody bifurcated stent graft for endovascular treatment of isolated abdominal aortic dissection (IAAD).

BACKGROUND

Isolated abdominal aorta dissection (IAAD) is a rare event. Endovascular stent grafts seem to offer an efficient therapeutic approach to treat IAAD. However, the relatively small diameter of the infrarenal aorta and aortic bifurcation remains the main anatomical limitation to endovascular repair.

METHODS

Between 2008 and 2015, we retrospectively evaluated 32 IAAD patients (21 men; mean age 58 ± 18 years), who underwent endovascular repair using Aegis™-B unibody bifurcated stent graft. Narrow proximal landing zone and narrow distal aorta was present in 11 (34.4%) patients and 10 (31.3%) patients, respectively. In the follow-up period, aortic remodeling was observed with computed tomography angiography.

RESULTS

All patients were treated by endovascular means, with a primary technical success rate of 100%. During a mean follow-up period of 30.71 ± 16.36 months (range, 8-56 months), no death, rupture, stent fracture, material failure, or device migration was observed. Complete false lumen thrombosis was observed in all patients at 1 year, and all patients were free from false lumen growth in the follow-up.

CONCLUSIONS

Endovascular treatment of IAAD using the Aegis™-B system appears to be safe and effective. Results from this study suggest this algorithm can provide stable, secure fixation for IAAD patients with narrow proximal landing zone, and distal aorta.

Recent evolution in use and effectiveness in mainland China of thoracic endovascular aortic repair of type B aortic dissection

A meta-analysis was performed on 175 studies selected among those published in mainland China between 2008 and 2015 on thoracic endovascular aortic repair (TEVAR) for type B aortic dissection (AD). Most TEVAR were performed in Shanghai, Beijing, Hubei and Guangdong in patients with mean age of 53.9 years, and acute (70%) or chronic (30%) type B AD. Procedural success rate was 99.1 ± 0.8%. Major complication rate was 1.7 ± 2.3%, with paraplegia in 0.4 ± 0.0%. Overall in-hospital mortality rate was 1.6 ± 0.9% with AD rupture in 30% (about 40% during first postoperative day); follow-up mortality rate was 2.3 ± 1.1%, with AD rupture in 39.2% (50% within first year). Compared with 2001–2007 data from China, there appeared to be improvement in rates of major complications, paraplegia and in-hospital mortality. Compared with 1999–2004 Western data, rates of procedural success, stroke, and paraplegia appeared similar, while those for major complications, in-hospital mortality, retrograde type A dissection and follow-up mortality appeared lower. Compared with more recent Western data (2006–2013) on acute complicated type B AD, stroke, paraplegia, in-hospital mortality and follow-up mortality appeared lower. Therefore, in mainland China, safety for TEVAR of type B AD appeared better between 2008 and 2015 than in previous periods in China or Western countries.

Restrictive bare stent prevents distal stent graft-induced new entry in endovascular repair of type B aortic dissection

OBJECTIVE

Distal stent graft-induced new entry (SINE) can occur after thoracic endovascular aortic repair (TEVAR) of type B aortic dissection. This study investigated the mechanism of distal SINE and its prevention using a restrictive bare stent (RBS) technique.

METHODS

From January 2013 to December 2014, 68 consecutive type B aortic dissection patients received endovascular repair at our center. The RBS technique was used with distal oversizing (between the diameter of the thoracic stent graft and the descending aorta true lumen diameter at the level of the intended distal edge of the thoracic stent graft) >20%.

RESULTS

Twenty-three patients received TEVAR with a single thoracic stent graft (TEVAR group, n = 23); the rest received TEVAR combined with the RBS technique (TEVAR + RBS group, n = 45). Four distal SINEs occurred in the TEVAR group. Distal oversizing (69.7% ± 35.5% vs 31.2% ± 24.5%; P = .005) and expansion mismatch ratio (132.2% ± 16.9% vs 106.5% ± 11.6%; P < .05) were significantly higher in the SINE patients. Compared with standard TEVAR, TEVAR + RBS was associated with significantly lower distal oversizing (TEVAR vs TEVAR + RBS group, 59.8% ± 24.7% vs 16.7% ± 7.6%; P < .05), lower expansion mismatch ratio (113.8% ± 14.6% vs 103.8% ± 11.7%; P = .012), and lower distal SINE rate (4/23 [17.4%] vs 0/45 [0%]; P = .011). Compared with the TEVAR group, the false lumen was reduced significantly at the level of the RBS distal edge (P = .029).

CONCLUSIONS

Excessive distal oversizing and distal expansion mismatch ratio may contribute to the occurrence of distal SINE. The RBS technique reduced the incidence of distal SINE. Based on our midterm and long-term observations, implantation of an RBS may improve aortic remodeling.

Endovascular Stent-Graft Placement in Patients with Stanford Type B Aortic Dissection in China: A Systematic Review

BACKGROUND

Improvements in stent-graft devices and increasing clinical experience with the technique have improved outcomes and expanded clinical indications in patients with Stanford type B aortic dissection (AD) in China. However, the evolution of and modifications to stent grafts have not been reviewed. The aim of this study was to summarize all available published data on technical success, potential benefits, complications, stent evolution, and survival rates associated with endovascular stent-graft placements in patients with Stanford type B AD in China.

METHODS

We performed comprehensive searches of the Chinese-language medical literature in Chinese Biomedical Database, China National Knowledge Infrastructure, and Wanfang Data and of the English-language medical literature in PubMed, Web of Science, and the Cochrane Library. This systematic review was based on all retrospective studies assessing outcomes of Stanford type B AD treated with endovascular stent-graft placement in China.

RESULTS

A total of 153 retrospective studies that included 8,694 cases were analyzed in this study. Procedure success was reported in 99.7 ± 0.1% of patients. Overall complications were reported in 19.1 ± 0.6% of patients. Postoperative endoleaks occurred in 7.2 ± 0.3% of patients. Major complications were reported in 3.2 ± 0.2% of patients, with a neurological complication rate of 1.3 ± 0.1%. Periprocedural stroke occurred more frequently than did paraplegia (0.8 ± 0.1% vs. 0.1 ± 0.04%). Overall complications were significantly greater in patients treated with first-generation stents than in those treated with second-generation stents (25.1 ± 1.2% vs. 9.5 ± 0.9%, P < 0.001). The in-hospital mortality rate was 1.6 ± 0.1%. In addition, 1.8 ± 0.2% of patients died during a mean follow-up period of 29.4 ± 13.5 months. The Kaplan-Meier estimates of the overall survival rate were 99.0 ± 0.1% at 30 days, 98.5 ± 0.2% at 6 months, 98.4 ± 0.2% at 1 year, 98.1 ± 0.2% at 2 years, and 97.9 ± 0.2% at 5 years.

CONCLUSIONS

Endovascular stent-graft placement is feasible and has a high technique success rate as well as favorable neurological complication and survival rates when used to treat Stanford type B AD. The new generation of stent grafts appears to have favorable in-hospital and follow-up outcomes.

Risk factors for distal stent graft-induced new entry following endovascular repair of type B aortic dissection

BACKGROUND

Distal stent graft-induced new entry (DSINE) has been increasingly observed following thoracic endovascular aortic repair (TEVAR) for type B aortic dissection (TBAD). We seek to identify the risk factors for DSINE following TEVAR in patients with TBAD.

METHODS

Between January 2009 and January 2013, we performed TEVAR for 579 patients with TBAD. The clinical data were retrospectively analyzed with univariate and multivariate analyses to identify the risk factors for DSINE.

RESULTS

Two patients (0.3%) died after the initial TEVAR. Morbidity included spinal cord injury in 2 (0.3%), stroke in 3 (0.5%) and endoleak in 12 (2.1%) patients. Clinical and radiological follow-up was complete in 100% (577/577) averaging 47±16 months. Late death occurred in 6 patients. DSINE occurred in 39 patients (6.7%) at mean 22±17 months after the initial TEVAR, which was managed with re-TEVAR in 25 and medically in 14. At 33±18 months after DSINE, 11 of patients managed medically (11/14) and all patients managed with re-TEVAR (25/25) survived (P=0.048). Freedom from DSINE was 92.7% at 5 years (95% CI: 90.0-94.7%). Using tapered stent grafts with a proximal end 4-8 mm larger than the distal end, TEVAR performed in the acute phase (≤14 days from onset) was associated with a significantly lower incidence of DSINE than TEVAR performed in the chronic phase (4.3%, 7/185 vs. 13.9%, 15/108; P=0.003). Risk factors for DSINE were stent grafts less than 145 mm in length [odds ratio (OR) 2.268; 95% CI: 1.121-4.587; P=0.023] and TEVAR performed in the chronic phase (OR 1.935; 95% CI: 1.004-3.731; P=0.049).

CONCLUSIONS

Our results show that TEVAR performed during the acute phase and using stent grafts longer than 145 mm could decrease the incidence of DSINE in patients with TBAD. Tapered stent grafts with a proximal end 4-8 mm larger than the distal end may be helpful in preventing DSINE after TEVAR performed in the acute phase than TEVAR performed in the chronic phase, due to the difference in mobility of the dissected flap. Expedite repeat TEVAR is recommended to improve the clinical prognosis for patients with DSINE.

Biomechanical Changes After Thoracic Endovascular Aortic Repair in Type B Dissection

Thoracic endovascular aortic repair (TEVAR) has evolved into an established treatment option for type B aortic dissection (TBAD) since it was first introduced 2 decades ago. Morbidity and mortality have decreased due to the minimally invasive character of TEVAR, with adequate stabilization of the dissection, restoration of true lumen perfusion, and subsequent positive aortic remodeling. However, several studies have reported severe setbacks of this technique. Indeed, little is known about the biomechanical behavior of implanted thoracic stent-grafts and the impact on the vascular system. This study sought to systematically review the performance and behavior of implanted thoracic stent-grafts and related biomechanical aortic changes in TBAD patients in order to update current knowledge and future perspectives.

Operative Results and Clinical Features of Chronic Stanford Type B Aortic Dissection: Examination of 234 Patients Over 6 Years

OBJECTIVE/BACKGROUND

Recently, the indications for thoracic endovascular aortic repair (TEVAR) have been expanding, and the applicability of TEVAR for acute type B aortic dissection (TBAD) is proposed with regard to the high mortality of open surgery for chronic TBAD. TEVAR in the acute phase may lead to remodeling of the false lumen (FL), but it is controversial whether it completely resolves the aortic expansion in the chronic phase. In this study, operative results and the relationship between FL status and the time before surgical intervention were retrospectively analyzed.

METHODS

From January 2008 to September 2013, 234 patients underwent open surgery for chronic TBAD. Most patients were on left heart bypass. By considering Japanese aortic disease treatment guidelines and the smaller physique of Japanese patients, operative indications were aneurysm >50 mm in diameter or rapid aneurysm enlargement of >5 mm in a 6 month period.

RESULTS

In 180 cases, the FL was patent. The mean interval between onset of TBAD and operation was 61 ± 54 months. There was no significant difference between patients in the patent FL group and those in the thrombosed FL group (p = .44). Mean ratio of FL diameter to maximum aortic diameter (FL/AD) was 0.64 ± 0.21. There was no correlation between FL and AD before the operation (r = .12). Descending thoracic aortic replacement (DTAR) was performed in 127 cases and thoracic ascending aortic replacement (TAAR) in 107 cases (Crawford type I, n = 9; Crawford type II, n = 65; Crawford type III and IV, n = 22, respectively; Safi type V, n = 11). The overall operative mortality was 6.8%: 3.9% (5/127) for DTAR and 10.3% (11/107) for TAAR. The three year survival was 86.7, and the freedom from re-intervention rate was 97.0%.

CONCLUSION

Enlargement of uncomplicated TBAD in the chronic phase was poorly related to FL status and the results of open repair have improved. However, further prospective study is necessary.