Volume changes in aortic true and false lumen after the "PETTICOAT" procedure for type B aortic dissection

Interventions in Acute or Subacute Phase for Type B Aortic Dissection

The treatment strategy for acute and subacute Stanford type B aortic dissection has changed significantly since the advent of thoracic endovascular aortic repair (TEVAR). Indication for invasive treatment: In addition to the conventional complicated cases (rupture or malperfusion case), the indication for invasive treatment now includes cases with refractory hypertension, persistent or recurrent pain, large aortic diameter, and other conditions that are considered to have a poor prognosis with conservative treatment. Treatment methods: TEVAR is the first choice for acute, subacute, and early chronic-stage treatment, and when this is not possible, other techniques (fenestration and graft replacement) are chosen. Treatment timing: The timing of invasive treatment should be emergent in life-threatening conditions (for rupture or malperfusion case) and immediate in symptomatic cases, while in other cases, preemptive TEVAR is considered appropriate on a scheduled timing within 6 months of onset. (This is a translation of Jpn J Vasc Surg 2023; 32: 157-163.).

Volumetric analysis in primary and residual type B aortic dissection treated with stented-assisted balloon-induced intimal disruption and relamination technique can predict aortic reintervention

OBJECTIVE

The aim of this study was to investigate the mid-term results of stented-assisted balloon-induced intimal disruption and relamination (STABILISE) in patients with aortic dissection with the implementation of volumetric analysis.

METHODS

This was a single-center retrospective analysis of prospectively collected data. From May 2017 to September 2022, 42 patients underwent STABILISE for acute complicated or subacute high-risk aortic dissection. STABILISE was completed with distal extended endovascular aortic repair in 24 patients. A computed tomography scan was performed at baseline, before hospital discharge, and at 1, 3, and 5 years. Perfused total aortic, true lumen, and false lumen volumes were assessed for thoracic, visceral, and aorto-iliac segment. The ratio between false lumen and total volume was named perfusion dissection index (PDI). Complete remodeling was defined as PDI = 0, and positive remodeling as PDI ≤0.1.

RESULTS

Technical success was 97.6%. No 30-day deaths, spinal cord injuries, or retrograde dissections were observed. Mean follow-up was 44 ± 19.4 months. Thoracic diameter was lower at last available computed tomography scan (36.7 vs 33.0 mm; P = .01). Aortic growth >5 mm was observed in 9.5% of the patients. Thoracic and visceral aortic complete remodeling were 92.8% and 83.3%, respectively, with no difference between acute and subacute group. Distal extended endovascular aortic repair significantly increased complete remodeling in the aorto-iliac segment, compared with STABILISE alone (69.6% vs 21.4%; P < .001). Freedom from vascular reinterventions at 3 years was 83.1% (95% confidence interval, 71.5%-96.6%). Total PDI ≤0.1 at first postoperative control was a predictor of vascular reinterventions (P < .0001).

CONCLUSIONS

STABILISE is a safe and feasible technique associated with high mid-term rates of complete remodeling in the thoracic and visceral aorta. Volumetric analysis allows the quantification of aortic remodeling and represents a predictor of aortic reinterventions.

Outcomes of fenestrated endovascular abdominal aortic repair in distal entry tears of chronic debakey IIIb aortic dissection

Currently, there have been very few reports within the literature which specifically address using fenestrated and branched stent grafts to completely isolate and repair distal entry tears of chronic DeBakey IIIb aortic dissection. This study aimed to evaluate the clinical outcomes of a 3-dimensional (3D) printed aortic model-guided fenestrated stent in the treatment of distal tears of chronic DeBakey IIIb aortic dissection after thoracic endovascular aortic repair (TEVAR). The study was a one-center retrospective study comprising 36 patients who underwent TEVAR and fenestrated endovascular abdominal aortic repair (F-EVAR) between April 2014 and December 2022. Patient data was compiled and analysed for preoperative, intraoperative, and perioperative characteristics. In total, 36 patients (12 females and 24 males) were incorporated into this study. All of the patients included in this study had hypertension, and among them, the leading cause for undergoing II-stage F-EVAR was the progression of a false lumen, accounting for 24 cases (66.7% of the total). The technical success rate was 97.2% and there were no cases of 30-day mortality, myocardial infarction, permanent paraparesis, or organ failure. One year post-F-EVAR treatment, surviving patients showed significant false and true lumen remodelling with 100% complete false-lumen thrombosis. A total of five patients died during the follow-up, two patients died related to aorta complications and three patients died of heart failure, multiple organ failure, or septic shock. II-stage F-EVAR was safe and feasible operation to repair all distal tears of chronic DeBakey IIIb aortic dissection.

Hemodynamic Implications of STABILISE Technique for Aortic Dissection Repair

BACKGROUND

The stent-assisted balloon-induced intimal disruption and relamination (STABILISE) technique for treatment of type B dissection has shown promising clinical results at mid-term. Computational modeling is a way of noninvasively obtaining hemodynamic effects, such as pressure and wall shear stress, leading to a better understanding of potential benefits. Particular areas of interest are (1) the effect of intimal disruption and re-lamination and (2) the effect of the bare metal stent in the visceral aortic segment.

METHODS

Single-center prospective case series. Data from 5 consecutive locally performed cases of STABILISE technique were analyzed. Included cases were type B aortic dissection with or without prior de-branching. The STABILISE procedure had to be performed without 30-day major complications. Preoperative and postoperative imaging data for each patient were transferred to the biomedical engineering team. Each case was reconstructed, meshed, and simulated with computational fluid dynamics using patient-specific data (heart rate, blood pressure, height, and weight). Hemodynamic parameters were then extracted from the simulations.

RESULTS

In all cases, computational analysis showed for postoperative patients: (1) a drop in pressure difference between lumina and (2) lower wall shear stress effects, compared to their preoperative status. These observations were most pronounced in the visceral aortic segment.

CONCLUSIONS

Computational modeling shows favourable changes in the flow dynamics of type B dissection treated using the STABILISE technique. This may suggest protective effects of this technique for long-term aortic healing and cicatrization.

The Rate of Postoperative Complications in Complicated Acute, and Subacute Type B Aortic Dissections after TEVAR vs. PETTICOAT Procedures: Systematic Review and Meta-Analysis

Background and Objectives: Provisional extension to induce complete attachment (PETTICOAT) is suggested as being associated with a lower incidence of aorta-related events and fewer reinterventions compared to thoracic endovascular aortic repair (TEVAR) in patients with complicated acute, and subacute type B aortic dissections. Materials and Methods: This article is a systematic review and meta-analysis following the PRISMA guidelines. The Medline, PubMed, Embase, and Cochrane databases were searched, starting on 21 February 2022 and ending on 22 June 2022, to identify studies that investigated the rate of postoperative complications in patients treated with the PETTICOAT compared to the TEVAR. A random effects meta-analysis was performed. Of 2350 studies, 5 studies involving 360 patients were included: 143 patients after the PETTICOAT procedure and 217 after the TEVAR. Results: The meta-analysis of all studies showed that the rate of secondary endovascular reinterventions was smaller in patients treated with the PETTICOAT (n = 3 studies; OR, 0.30; 95% CI, 0.10 to 0.94; p = 0.04). The results of other postoperative complications (30-day mortality, mortality during follow-up, paraplegia, stroke, and occurrence of endoleak) were lower in the PETTICOAT group but were not statistically significant. The rate of postoperative renal failure was lower in patients treated with the TEVAR (n = 4; OR, 1.08; 95% CI, 0.46 to 2.51; p = 0.86). Conclusion: This meta-analysis suggests that the PETTICOAT procedure is related to the lower rate of secondary endovascular reinterventions for complicated acute, and subacute type B aortic dissections.

Open and endovascular reinterventions after Candy Plug false lumen embolization of type B aortic dissection

OBJECTIVE

In the majority of patients with chronic type B aortic dissection, there is persistent retrograde flow in the false lumen (FL) through distal re-entry tears. Among several endovascular techniques proposed for FL management, the "Candy Plug" (CP) technique has gained acceptance with good early results. The aim of this study is to report the types and outcomes of open and endovascular reinterventions and identify mechanisms of procedure failure as well as other causes for reinterventions.

METHODS

All patients with type B aortic dissection submitted to thoracic endovascular aneurysm repair and CP implantation for FL embolization from January 2016 to December 2022 at our institution were included in this study. The preoperative, intraoperative, and postoperative data of the primary intervention and secondary reinterventions, when performed, were prospectively collected and retrospectively analyzed. Preoperative and postoperative computed tomography angiography were also analyzed.

RESULTS

During the study period, 33 patients were submitted to thoracic endovascular aneurysm repair and CP implantation. Twenty-three patients (69.7%) showed thoracic FL complete thrombosis with aortic stability or positive remodeling at a mean follow-up of 45 ± 23.1 months. Ten patients (30.3%) underwent aortic reinterventions (male, n = 9; mean age, 60.5 ± 7.6 years). Of these 10 patients, in four patients, complete thrombosis of the FL was never achieved, leading to ongoing perfusion of the FL, defined as "primary failure." The other six patients underwent reinterventions for different causes: two patients, after initial sealing, showed a progressive enlargement of the abdominal FL leading to distal degeneration. One patient showed proximal degeneration, two patients showed a type II thoracoabdominal aortic aneurysm and CP implantation was used as a planned procedure to reduce the extent of the surgical procedure, and one patient had recurrent, intractable back pain despite complete thrombosis of the FL. Reinterventions were open in five cases and endovascular in five. One in-hospital death (postoperative day 27) after a type II thoracoabdominal aortic aneurysm open repair was recorded. In addition, two cases of delayed spinal cord ischemia after open reintervention were recorded: one resulting in permanent paraplegia and one transitory with complete recovery.

CONCLUSIONS

The CP technique was safe and effective; however, a significant rate of aortic-related reintervention was observed. Several mechanisms led to reinterventions either in terms of "primary failure" of the CP or subsequent aneurysmal degeneration. Complex reinterventions were often necessary, with a high rate of major complications in case of open repair. Life-long and closer surveillance might be required in these patients.

Aortic rupture during STABILISE (stent-assisted balloon-induced intimal disruption and relamination in aortic dissection repair) technique

The STABILISE (stent-assisted balloon-induced intimal disruption and relamination in aortic dissection repair) technique has shown promising results for treating type B aortic dissections, but the potential exists for fatal adverse effects. We present a case of infrarenal aortic rupture while using a compliant balloon to balloon mold the true lumen inside previously placed bare metal stents during the STABILISE technique. Caution is advised for providers who wish to perform the STABILISE technique, and we recommend using a semi-compliant balloon sized to the smallest total aortic diameter to mitigate the risk of rupture.

Deep learning-based multi-stage postoperative type-b aortic dissection segmentation using global-local fusion learning

Objective.Type-b aortic dissection (AD) is a life-threatening cardiovascular disease and the primary treatment is thoracic endovascular aortic repair (TEVAR). Due to the lack of a rapid and accurate segmentation technique, the patient-specific postoperative AD model is unavailable in clinical practice, resulting in impracticable 3D morphological and hemodynamic analyses during TEVAR assessment. This work aims to construct a deep learning-based segmentation framework for postoperative type-b AD.Approach.The segmentation is performed in a two-stage manner. A multi-class segmentation of the contrast-enhanced aorta, thrombus (TH), and branch vessels (BV) is achieved in the first stage based on the cropped image patches. True lumen (TL) and false lumen (FL) are extracted from a straightened image containing the entire aorta in the second stage. A global-local fusion learning mechanism is designed to improve the segmentation of TH and BR by compensating for the missing contextual features of the cropped images in the first stage.Results.The experiments are conducted on a multi-center dataset comprising 133 patients with 306 follow-up images. Our framework achieves the state-of-the-art dice similarity coefficient (DSC) of 0.962, 0.921, 0.811, and 0.884 for TL, FL, TH, and BV, respectively. The global-local fusion learning mechanism increases the DSC of TH and BV by 2.3% (p< 0.05) and 1.4% (p< 0.05), respectively, based on the baseline. Segmenting TH in stage 1 can achieve significantly better DSC for FL (0.921 ± 0.055 versus 0.857 ± 0.220,p< 0.01) and TH (0.811 ± 0.137 versus 0.797 ± 0.146,p< 0.05) than in stage 2. Our framework supports more accurate vascular volume quantifications compared with previous segmentation model, especially for the patients with enlarged TH+FL after TEVAR, and shows good generalizability to different hospital settings.Significance.Our framework can quickly provide accurate patient-specific AD models, supporting the clinical practice of 3D morphological and hemodynamic analyses for quantitative and more comprehensive patient-specific TEVAR assessments.

One year follow-up outcomes of endovascular treatment for aortic dissection with a partial micropore stent graft in which fixation of the stent is done in zone 0: A pivotal trial first in human

OBJECTIVE

This study aimed to verify the efficacy and safety of the treatment for patients diagnosed with DeBakey type I and type III thoracic aortic dissections using a partial micropore stent graft.

METHODS

We conducted a retrospective analysis of 32 patients who suffered from thoracic aortic dissection and underwent endovascular repair using a partial micropore stent graft at our center between December 2018 and January 2020.

RESULTS

The technical success rate for 32 patients was 100 %, while no 30-day mortality was observed. In the 30 patients finished follow-ups, 30 (mean: 1 per patient) micropore stents were implanted, while the openings of 90 (mean: 3 per patient) aortic arch branches were covered by the stents. After more than 12 months follow-up, 26 (86.7 %) of the 30 patients presented with a complete thrombosis in the false lumen, and 4 (13.3 %) patients presented with a partial thrombosis in the false lumen. All 90 aortic arch branches were patent. No aortic arch branch artery stenosis or occlusion was observed.

CONCLUSIONS

The outcomes obtained during 12 months of follow-up suggested that performing endovascular repair for thoracic aortic dissection patients with a partial micropore stent graft is safe and effective, maintaining the patency of aortic arch branch vessels.

Balloon Inducted Re-Lamination and False lUmen Thrombosis in Chronic Type B Aortic Dissection: Technique and Long-Term Results

BACKGROUND

To evaluate the safety, feasibility, and effectiveness of the BAlloon Inducted re-Lamination and false lUmen Thrombosis (BAILOUT) as a simple technique to address the retrograde false lumen (FL) perfusion and subsequent aneurysmatic degeneration of the thoracic aorta due to a stent-graft crimped in a small true lumen in chronic Type B dissections.

METHODS

An observational, retrospective, single-center study analyzing a nonconsecutive cohort of 8 patients affected by chronic type B aortic dissections already treated with thoracic endovascular repair and with an FL lumen backflow corrected with BAILOUT between 2006 and 2020. After a standard distal extension of the previously implanted graft, the distal end of the graft area was ballooned to completely rupture the dissection lamella to relaminate the aorta hindering the FL backflow. Computed tomography was routinely performed within the first postoperative week before discharge and then at 3 months, at 6 months, and yearly thereafter. The technical and clinical success rates were analyzed. Primary outcomes were safety and feasibility of the technique, secondary ones included FL thrombosis evaluation, and total aortic diameter analysis at the above-defined levels during the follow-up. Safety was defined if clinical success was reached. Feasibility was intended as technical success obtention.

RESULTS

The technical and clinical success achieved was 100% with the complete interruption of FL backflow stating the safety and feasibility of the BAILOUT technique. No early procedure reinterventions were recorded and during a median follow-up of 62.5 months [interquartile range 43.2-94.1], only 1 death unrelated to the procedure was recorded. Freedom from aortic-related adverse events at 1 month, 3 months, 1 year, 5, and 7 years was 87.5%, 62.5%, 62.5%, 62.5%, and 62.5%, respectively. During the follow-up, no one increment of the diameter of the thoracic aorta was documented and all the patients at 3 years of computed tomography angiography showed a complete FL thrombosis.

CONCLUSIONS

The BAILOUT technique demonstrates to be safe and feasible in this small cohort of patients as a simple and quick way to overcome the issue of FL backflow in chronic type B dissection. Small cohort and retrospective designs were limitations of the study.

Midterm Results of Thoracic Endovascular Aortic Repair with Reentry Closure for Chronic Type B Aortic Dissection with Aneurysmal Dilatation

Objectives: This study aims to discuss the midterm results of thoracic endovascular aortic repair (TEVAR) with reentry closure for chronic type B aortic dissection (CTBAD). Materials and Methods: This retrospective study analyzed 13 patients with CTBAD who underwent TEVAR with reentry closure between July 2014 and December 2020. We evaluated the false lumen (FL) cross-sectional area using computed tomography images of the descending aorta at the level of the bronchial bifurcation, Valsalva sinus, celiac artery, and infrarenal abdominal aorta pre- and postoperation. The study endpoints were technical and clinical success rates, freedom from additional aortic reintervention or surgery, and survival. Results: Technical success was obtained in 12 patients (92.3%) with no hospital mortality and neurological complications. The postoperative observation period was 49.2±21.5 months. The clinical success rate was 76.9% (10 cases), and a postoperative reduction of the FL cross-sectional area was obtained in 53.8% of patients. The 5-year overall survival rate was 64.8% with no aortic-related deaths while the 5-year freedom from additional aortic surgery rate was 66.7%. Conclusions: TEVAR with reentry closure suggests preventing FL dilatation or rupture in CTBAD, but the revision of our devices and further research with more patients and longer follow-up periods are required.

Volume Analysis to Predict the Long-Term Evolution of Residual Aortic Dissection after Type A Repair

Background: The aim of this study was to evaluate the aortic diameter and volume during the first year after a type A repair to predict the long-term prognosis of a residual aortic dissection (RAD). Methods: All patients treated in our center for an acute type A dissection with a RAD and follow-up > 3 years were included. We defined two groups: group 1 with dissection-related events (defined as an aneurysmal evolution, distal reintervention, or aortic-related death) and group 2 without dissection-related events. The aortic diameters and volume analysis were evaluated on three postoperative CT scans: pre-discharge (T1), 3−6 months (T2) and 1 year (T3). Results: Between 2009 and 2016, 54 patients were included. Following a mean follow-up of 75.4 months (SD 31.5), the rate of dissection-related events was 62.9% (34/54). The total aortic diameters of the descending thoracic aorta were greater in group 1 at T1, T2 and T3, with greater diameters in the FL (p < 0.01). The aortic diameter evolution at 3 months was not predictive of long-term dissection-related events. The total thoracic aortic volume was significantly greater in group 1 at T1 (p < 0.01), T2 (p < 0.01), and T3 (p < 0.01). At 3 months, the increase in the FL volume was significantly greater in group 1 (p < 0.01) and was predictive for long-term dissection-related events. Conclusion: This study shows that an initial CT scan volume analysis coupled with another at 3 months is predictive for the long-term evolution in a RAD. Based on this finding, more aggressive treatment could be given at an earlier stage.

Thoracic Endovascular Aortic Repair for Chronic Type B Aortic Dissection: Pre- and Postprocedural Imaging

Aortic dissection is a chronic disease that requires lifelong clinical and imaging surveillance, long after the acute event. Imaging has an important role in prognosis, timing of repair, device sizing, and monitoring for complications, especially in the endovascular therapy era. Important anatomic features at preprocedural imaging include the location of the primary intimal tear and aortic zonal and branch vessel involvement, which influence the treatment strategy. Challenges of repair in the chronic phase include a small true lumen in conjunction with a stiff intimal flap, complex anatomy, and retrograde perfusion from distal reentry tears. The role of thoracic endovascular aortic repair (TEVAR) remains controversial for treatment of chronic aortic dissection. Standard TEVAR is aimed at excluding the primary intimal tear to decrease false lumen perfusion, induce false lumen thrombosis, promote aortic remodeling, and prevent aortic growth. In addition to covering the primary intimal tear with an endograft, several adjunctive techniques have been developed to mitigate retrograde false lumen perfusion. These techniques are broadly categorized into false lumen obliteration and landing zone optimization strategies, such as the provisional extension to induce complete attachment (PETTICOAT), false lumen embolization, cheese-wire fenestration, and knickerbocker techniques. Familiarity with these techniques is important to recognize expected changes and complications at postintervention imaging. The authors detail imaging options, provide examples of simple and complex endovascular repairs of aortic dissections, and highlight complications that can be associated with various techniques. Online supplemental material is available for this article. ^©RSNA, 2022.

Five-year results of the STABLE II study for the endovascular treatment of complicated, acute type B aortic dissection with a composite device design

OBJECTIVE

To provide the five-year outcomes of the use of a composite device (proximal covered stent-graft + distal bare stent) for endovascular repair of patients with acute, type B aortic dissection complicated by aortic rupture and/or malperfusion.

METHODS

STABLE II was a prospective, multicenter study of the Zenith Dissection Endovascular System (William Cook Europe, Denmark). Patients were enrolled between August 2012 and January 2015 at sites in the United States and Japan. Five-year follow-up was completed by January 2020.

RESULTS

In total, 73 patients (mean age 60.7±10.9 years; 65.8% male) with acute type B dissection complicated by malperfusion (72.6%), rupture (21.9%), or both (5.5%) were enrolled. Patients were treated with either a composite device (79.5%) or the proximal stent-graft alone (no distal bare stent, 20.5%). Dissections were more extensive in patients who received the composite device (408.9±121.3 mm) than in patients who did not receive a bare stent (315.9±100.1 mm). Mean follow-up was 1209.4±754.6 days. Freedom from all-cause mortality was 80.3%±4.7% at one year and 68.9%± 7.3% at five years. Freedom from dissection-related mortality remained at 97.1%±2.1% from one-year through five-year follow-up. Within the stent-graft region, the rate of either complete thrombosis or elimination of the false lumen increased over time (82.1% of all patients at five years vs. 55.7% at first post-procedure CT), with a higher rate at five years in patients who received the composite device (90.5%) compared with patients without the bare stent (57.1%). Throughout follow-up, overall true lumen diameter increased within the stent-graft region, and overall false lumen diameter decreased. At five years, 20.7% of patients experienced a decrease in maximum transaortic diameter within the stent-graft region, 17.2% experienced an increase, and 62.1% experienced no change. Distal to the treated segment (but within the dissected aorta), 23.1% of patients experience no change in transaortic diameter at five years; a bare stent was deployed in all these patients at the procedure. Five-year freedom from all secondary intervention was 70.7%±7.2%.

CONCLUSIONS

These five-year outcomes indicate a low rate of dissection-related mortality for the Zenith Dissection Endovascular System in the treatment of patients with acute, complicated type B aortic dissection. Further, these data suggest a positive influence of composite device use on false lumen thrombosis. Continuous monitoring for distal aortic growth is necessary in all patients.

Endovascular interventions in main renal artery pathologies: an overview and update

Renal arteries are involved in a wide spectrum of pathologies including atherosclerosis, fibromuscular dysplasia, Takayasu arteritis, aneurysms, and aortic type B dissections extending into main renal arteries. They manifest as renovascular hypertension, renal ischemia, and cardiovascular dysfunction. The location of the renal arteries in relation to the abdominal aortic aneurysm is a critical determinant of interventional options and long-term prognosis. This article provides a comprehensive review of the role of interventional radiologists in transcatheter interventions in various pathologies involving the main renal arteries with analysis of epidemiology, pathophysiology, newer interventional techniques, and management options.

Initial Study of the Extended STABILISE Technique for Complete Remodeling in Aortic Dissection

OBJECTIVES

Thoracic endovascular aortic repair (TEVAR) is the standard treatment for acute complicated type B aortic dissection (TBAD). However, long-term results reveal that TEVAR does not achieve a complete aortic remodeling and poses a risk of aneurysmal aortic degeneration. Distal reentry treatment at the abdominal level seems to be necessary to obtain a complete remodeling in TBAD. Moreover, it is necessary to treat the aortoiliac bifurcation in patients with persistent true lumen collapse or limb ischemia.

METHODS

Between January 2018 and October 2019, 11 patients with acute or sub-acute complicated TBAD or non-A non-B aortic dissection were treated in our institution in an endovascular fashion. We performed the stent-assisted balloon-induced intimal disruption and relamination in aortic dissection repair (STABLISE) technique in all cases, but two cases required complementary treatment of the aortoiliac bifurcation with a bifurcated AFX endograft system for limb ischemia due to true lumen collapse.

RESULTS

Technical success was obtained in all patients. No procedural complications occurred. No postoperative deaths, stroke, paraplegia, mesenteric, or renal ischemia were observed, and no secondary intervention was necessary. Satisfactory aortic remodeling was obtained after the follow-up periods with a 57.5% mean true lumen expansion.

CONCLUSION

Our initial experience using the extended STABILISE (e-STABILISE) technique using a bifurcated AFX endograft did not result in any postoperative mortality or complications. Without additional data, this technique should be reserved for specific patients who require revascularization of the aortoiliac bifurcation.

The STABILISE technique to address malperfusion on acute-subacute type B aortic dissections

Endovascular treatment is the current standard of care for complicated acute and subacute type B aortic dissection. Closure of the primary entry tear with thoracic endovascular aneurysm repair (TEVAR) is often insufficient to induce complete false lumen thrombosis and a positive aortic remodeling. Moreover, TEVAR does not solve all the cases of malperfusion. The Provisional ExTension to Induce COmplete ATtachment (PETTICOAT) technique (deploying self-expandable bare metal stents in the true lumen in addition to TEVAR) can re-expand the true lumen, stabilize the lamella and promote aortic remodeling, but it does not recreate a single-lumen aorta and long-term aneurysmal degeneration of the aorta is frequent. Endovascular treatment by means of TEVAR + PETTICOAT does not recreate a single-lumen aorta so long-term aneurysmal degeneration of the aorta is frequent. The stent-assisted, balloon-induced intimal disruption and relamination of aortic dissection (STABILISE) technique may help to this purpose disrupting the intimal lamella and creating a relaminated uni-luminal aorta.

Clinical Results and Aortic Remodeling After Endovascular Treatment for Complicated Type B Aortic Dissection With the “Fabulous” Stent System

Objective

To report the clinical outcomes and aortic remodeling after the implantation of a self-developed, biomechanically optimized, two-stage thoracic stent system named Fabulous.

Background

Given the efficacy of the PETTICOAT concept, the benefits of Fabulous and the behavior of remodeling in different segments need further investigation.

Methods

This is a prospective and multicenter study. From 2017 to 2019, 145 patients (mean age, 56.6 years; 88.3% male) from 14 centers were included in this cohort. The clinical results and core laboratory results were from a central electronic data capture system. Computed tomographic angiography was performed preoperatively, 1 month, 6 months and yearly thereafter and was used for volumetric analysis by 3mensio (Bilthoven, The Netherlands). After the 1-year follow-up, 97.2 and 87.6% of the clinical and imaging results of the eligible patients were available.

Results

Both stent grafts and bare stents were successfully delivered in place in 100% of the patients. The 30-day mortality and 1-year freedom from all-cause mortality were 2.1 and 96.6%, respectively. The incidence of entry flow was 11.7% at 30 days and 6.2% at 365 days. No cases of stent-induced new entry (SINE) or reintervention were observed. After the 1-year follow-up, the true lumen/overall volume ratio reached 88%. The following subdivided segment volume changes were recorded: stent graft segment TL +56%; FL −92%, bare stent segment TL +32%; FL −75%, and there were no significant changes in the visceral segment.

Conclusions

These outcomes indicated that there were favorable clinical benefits of Fabulous stent system. This device achieved a low short-term mortality and a low incidence of reintervention. In addition, patients undergoing Fabulous stent system implantation showed remodeling both on descending aorta and on the distal aorta. The volume changes in the TL and FL varied in the different segments. The long-term follow-up is still ongoing.

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.

Qualitative and Quantitative Assessments of Blood Flow on Tears in Type B Aortic Dissection With Different Morphologies

Objective: The interactions between aortic morphology and hemodynamics play a key role in determining type B aortic dissection (TBAD) progression and remodeling. The study aimed to provide qualitative and quantitative hemodynamic assessment in four different TBAD morphologies based on 4D flow MRI analysis. Materials and Methods: Four patients with different TBAD morphologies underwent CT and 4D flow MRI scans. Qualitative blood flow evaluation was performed by visualizing velocity streamlines and flow directionality near the tears. Quantitative analysis included flow rate, velocity and reverse flow index (RFI) measurements. Statistical analysis was performed to evaluate hemodynamic differences between the true lumen (TL) and false lumen (FL) of patients. Results: Qualitative analysis revealed blood flow splitting near the primary entry tears (PETs), often causing the formation of vortices in the FL. All patients exhibited clear hemodynamic differences between TL and FL, with the TL generally showing higher velocities and flow rates, and lower RFIs. Average velocity magnitude measurements were significantly different for Patient 1 (t = 5.61, p = 0.001), Patient 2 (t = 3.09, p = 0.02) and Patient 4 (t = 2.81, p = 0.03). At follow-up, Patient three suffered from left renal ischemia because of FL collapse. This patient presented a complex morphology with two FLs and marked flow differences between TL and FLs. In Patient 4, left renal artery malperfusion was observed at the 32-months follow-up, due to FL thrombosis growing after PET repair. Conclusion: The study demonstrates the clinical feasibility of using 4D flow MRI in the context of TBAD. Detailed patient-specific hemodynamics assessment before treatment may provide useful insights to better understand this pathology in the future.

The short-term safety and effectiveness of a new distal perforating stent graft in Type B aortic dissection: a retrospective study

Background

Spinal artery ischemia (SCI) events can result from over coverage of the descending thoracic aorta with a coated stent during Thoracic Endovascular Aortic Repair (TEVAR). The aim of this study was to determine whether a new distal perforating stent could reduce the incidence of spinal cord ischemia while remodeling the true lumen.

Methods

TBAD patients treated with Talos stent in the vascular surgery Department of Yan 'an Hospital affiliated to Kunming Medical University between December 2017 and October 2019 were retrospectively analyzed to investigate the short-term safety and effectiveness of Talos stent.

Results

A total of the 20 patients, including 14 males and 6 females, with an average age of 52.65 ± 8.98 years (range 37–68 years), were included in the analysis. Stent-grafts were successfully implanted in all patients under local anesthesia, with a technical success rate of 100%. The average operation time was 50.75 ± 13.01 min. A total of 2 cases (10%) presented chest pain associated with intercostal artery ischemia that was relieved on the 3rd and 5th postoperative day, respectively. Postoperative mean follow-up was 16.15 ± 3.99 months. No paraplegia or other complications occurred. And stenting did not induce new tears. No migration, deformation, or fracture of the stents occurred. There was a significant difference in the remolding of the true lumen preoperatively and at 12 months postoperatively (P < 0.05).

Conclusions

Talos stent has achieved satisfactory clinical treatment results in short term.

Towards Endovascular Treatment of Type A Aortic Dissection with Smaller Landing Zones and More Patient Eligibility

OBJECTIVE

Type A or ascending aortic dissection is an acute life-threatening condition with high morbidity and mortality. Open surgery remains standard-of-care. Development of minimally invasive endografts for Type A aortic dissection (TAAD) will require detailed understanding of dissection and aortic root anatomy to determine patient eligibility and optimal device specifications.

METHODS

Computed tomography images of TAAD cases at our institution from 2012-2019 were identified and three-dimensional reconstructions were performed using OsiriX 10.0 (Bernex, Switzerland). Analysis of key anatomic structures including centerline length measurements, ascending aorta/aortic root dimensions, as well as location and extent of dissection were determined in relation to coronary ostia.

RESULTS

A total of 53 patients were identified (mean±SD age 60.4±17.1 years; 36 male, 17 female), 46 of whom underwent surgery for TAAD. Four patients died within 30 days of surgery. In 47 patients (88.7%), the entry tear was distal to the highest coronary ostium. These cases were retrospectively considered for endovascular intervention with a non-branched, single endograft stent. Proximal landing zone (LZ) was defined as distance from the highest coronary ostium to entry tear: 35/53 (66.0%) had a proximal LZ length ≥2.0cm, 38/53 (71.7%) had proximal LZ length ≥1.5cm, and 42/53 (79.2%) had proximal LZ length ≥1.0cm. Proximal and distal LZ diameters of the sinotubular junction (STJ) and distal ascending aorta regions were (median [1^st quartile-3^rd quartile]) 3.29cm [2.73-4.10cm] and 3.49cm [3.09-3.87cm], respectively, with length from STJ to innominate takeoff 8.08cm [6.96-9.40cm]. Ascending aorta radius of curvature was 6.48cm [5.27-8.00cm]. 47.2% (25/53) of patients could be treated with a straight tube graft with ≤20% diameter mismatch between the proximal and distal LZ.

CONCLUSIONS

Almost 80% of patients with TAAD had a proximal LZ ≥1.0cm, and of these, 47.2% had anatomy amenable to endovascular therapy with a non-tapered straight tube graft commercially available devices. To increase patient eligibility for TAAD endovascular intervention, enhanced precision deployment with adequate seal in shorter LZs will be required. Our results serve as a guide for endovascular device specifications designed to treat this devastating condition.

Retrospective analysis of factors associated with aortic remodeling in patients with Stanford type B aortic dissection after thoracic endovascular aortic repair

Objective

Acute aortic dissection is a life-threatening condition. Thoracic endovascular aortic repair (TEVAR), together with optimized medical treatment, is currently the first line treatment for acute Stanford type B aortic dissection. TEVAR can close the entry tear and reduce mortality. Aortic remodeling after TEVAR can directly affect the patient’s long-term prognosis. The factors that influence aortic remodeling have, however, received insufficient clinical attention and remain unclear. It is very important to identify these factors.

Methods

A total of 100 patients were continuously enrolled from 2011 to 2018 in 2 centers. Relevant data, including time from hospital admission to surgery, medicine use and aortic computed tomography angiography images obtained before and 6 months after surgery were collected. Patients were divided into favorable and adverse aortic remodeling groups, according to the degree of aortic remodeling. Analysis of variance and the chi-square test were performed using SPSS software to compare differences between groups and to determine the factors that influence postoperative aortic remodeling.

Results

The proportion of single-stent implantations was higher in the favorable remodeling group than in the adverse remodeling group (79.5% vs. 53.8% in distal end of stent-graft level and 81.3% vs. 56.4% in diaphragm level, respectively, p < 0.05). The earlier the TEVAR procedure was performed, the better the aortic remodeling (3.4 days vs. 4.8 days in distal stent graft levels, and 3.6 days vs. 4.9 days in diaphragm level, respectively, p < 0.05), the presence of residual distal entry tears in the abdominal aorta also improved aortic remodeling after TEVAR (85.7% vs. 55.1% in the celiac trunk level, and 92.0% vs. 48.9% in the right renal artery level, respectively, p < 0.05).

Conclusion

Single stent-graft implantation and early surgery were associated with favorable aortic remodeling. Distal entry tears were also conducive to aortic remodeling after surgery for aortic dissection.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13019-021-01571-2.

Thoracic Endovascular Aortic Repair With Additional Distal Bare Stents in Type B Aortic Dissection Does Not Prevent Long-Term Aneurysmal Degeneration

PURPOSE

TEVAR (thoracic endovascular aortic repair) + PETTICOAT (Provisional ExTension to Induce COmplete ATtachment) technique has been selectively employed since 2005 at our institution during endovascular treatment of type B aortic dissection (TBD). The aim of this study is to evaluate the long-term (>5 years) clinical results and the evolution of aortic volume.

MATERIALS AND METHODS

All the patients receiving an endovascular treatment for TBD with the PETTICOAT technique were collected in a prospectively maintained database and follow-up computed tomography scan were retrospectively analyzed. Study endpoints included short- and long-term clinical success (absence of need for reintervention) and any major adverse event. The volumes of thoracic and abdominal aorta at long-term follow-up were also analyzed.

RESULTS

Twenty-eight patients received a TEVAR + PETTICOAT and were followed up (median follow-up 85 months). Primary 30-day clinical success rate was 82% with an adverse event rate of 31%; 4 type I endoleak and 1 retrograde dissection were recorded. Secondary mid-term clinical success was 96% while the long-term clinical success rate was 79%. Six cases (21%) received either an open repair or an endovascular repair for a significant distal aortic enlargement at follow-up. With regards to volumetric analysis, an increase of overall (thoracic and abdominal) aortic volume was observed in 8 cases mainly related to an increase (mean: +31%) of the abdominal volume that was observed in 11 cases.

CONCLUSIONS

PETTICOAT technique does not protect from long-term significant aneurysmal degeneration that may require aortic open or endovascular reinterventions. Aortic growth occurs mainly in the bare-stented aorta and thus, life-long surveillance is advisable in these patients.

Prediction of Distal Aortic Enlargement after Proximal Repair of Aortic Dissection Using Machine Learning

OBJECTIVES

This study aimed to construct a risk prediction model for distal aortic enlargement in patients with type B aortic dissection (TBAD) treated with proximal thoracic endovascular aortic repair (TEVAR).

METHODS

From June 2010 to June 2016, patients with TBAD who underwent proximal TEVAR were retrospectively analyzed. A total of 38 clinical and imaging variables were collected. Univariable logistic regression was conducted to explore potential risk factors associated with distal aortic enlargement. Elastic net regression was employed to select significantly influential variables. Then, machine learning algorithms (logistic regression (LR), artificial neutral network (ANN), random forest and support vector machine) were applied to build risk prediction models. The area under the receiver operating characteristic curve (AUC), sensitivity and specificity were used to evaluate the performance of these models.

RESULTS

A total of 503 patients were enrolled in this study. During the follow-up, 105 (20.9%) patients were identified as having distal aortic enlargement, and 69 (13.7%) patients were found to have distal aortic aneurysm formation. Five patients were identified with aortic rupture. True lumen collapse and multi-false lumens were two potential risk factors for distal aortic enlargement after proximal repair of TBAD. The LR model performed the best in predicting distal aortic enlargement, with the highest sensitivity (96.7%) and an AUC of 0.773. The best model for predicting distal aneurysm formation was the ANN model, which yielded the highest AUC (0.876) and a specificity of 79.1%.

CONCLUSIONS

Machine learning approaches can produce accurate predictions of distal aortic enlargement after proximal repair of TBAD, which potentially benefits subsequent management.

Quantification of volume changes in the descending aorta after frozen elephant trunk procedure using the Thoraflex hybrid prosthesis for type A aortic dissection

Background

Frozen elephant trunk (FET) is an established approach to reduce late complications of type A aortic dissection (AADA) by diminishing false lumen perfusion. Currently, surface size of aortic lumina are evaluated using Computed tomography (CT). However, this 2D method is prone to error as it evaluates dissection progression slice by slice. Volume measurement on the other hand can overcome this limitation and deliver better insights in aortic remodeling. Therefore, the aim was to quantify volume changes of the descending and abdominal aorta at short- and mid-term follow-up after FET.

Methods

Between April 2015 and March 2018, 20 patients who underwent surgical repair of AADA using the Thoraflex™ Hybrid Plexus (Vascutek, Terumo Aortic, Scotland) were included in this study. We measured volumetric change before surgical treatment, at discharge, at 12 and at 24 months based on CTAs (Computed tomography angiography). Surfaces and volumes have been analyzed using Aquarius iNtuition (TeraRecon Inc., Foster City, CA, USA).

Results

One hundred fifty-eight volumetric measures were obtained. The findings show a significant increase of volume of the true lumen (TL) while surface measurement of the TL did not show any significant change at other levels besides level C (diaphragm, P=0.00193). Variance analysis showed significant increase of volume, whereas no significant change was seen in false lumen. Post-hoc analysis revealed a significance at 24 months (P=0.047).

Conclusions

Although previous studies outline the clinical benefit of Thoraflex hybrid prosthesis on short-term follow up, this study provides a more precise understanding of aortic remodeling based on volumetric measurement. Thus, quantification of volume changes should be included for the assessment of optimal follow-up timing and consecutive procedure planning.

The provisional extension to induce complete attachment technique is associated with abdominal aortic remodeling and reduces aorta-related adverse events after aortic dissection

OBJECTIVE

This study evaluated the efficacy of the provisional extension to induce complete attachment (PETTICOAT) technique for type B and postoperative residual type B aortic dissections compared with the conventional thoracic endovascular aortic repair (TEVAR) technique.

METHODS

In this retrospective study, we compared sequential aortic morphologic changes in consecutive patients with type B and postoperative residual type B aortic dissections treated with the PETTICOAT technique between January 2016 and December 2017 with patients treated with the conventional TEVAR between January 2013 and December 2015. Outcomes included aortic remodeling and aorta-related adverse events for 2 years postoperatively.

RESULTS

Forty-eight patients were included in this study (24 in the PETTICOAT group, 24 patients in the conventional TEVAR group). Although both groups showed aortic remodeling in the descending thoracic aorta, the PETTICOAT group developed significantly better aortic remodeling in the abdominal aorta compared with the conventional TEVAR group during the observation period. The PETTICOAT group had significantly fewer aorta-related adverse events compared with the conventional TEVAR group (8% vs 54%; P < .001). Aorta-related adverse events more commonly occurred in the poor remodeling group compared with in the good remodeling group (P = .001; hazard ratio, 8.32; 95% confidence interval, 2.26-30.64).

CONCLUSIONS

This study suggests that the PETTICOAT technique for aortic dissection may promote aortic remodeling and decrease the incidence of aorta-related adverse events. Additional studies are required to confirm these preliminary findings.

Full PETTICOAT in acute type B aortic dissection with patent false lumen may offer positive remodeling for the distal aorta

OBJECTIVE

The provisional extension to induce complete attachment (PETTICOAT) technique is a unique thoracic endovascular aortic repair (TEVAR) for aortic dissection, which consists of proximal descending aortic endografting plus distal bare-metal stenting. This study aimed to investigate the efficacy of the PETTICOAT technique in patients with acute-sub-acute complicated type B aortic dissections. In particular, we compared the remodeling effect of full PETTICOAT covering down to the abdominal aorta with that of simple entry closure.

METHODS

In this retrospective pre-post study, we compared the clinical course of consecutive patients undergoing TEVAR with the PETTICOAT technique in which proximal entry tear was excluded with a covered stent, and extension bare stents were placed down to the abdominal segment for acute-sub-acute complicated type B aortic dissections, between 2015 and 2017, with a control group treated with TEVAR with entry closure between 2011 and 2015. Outcomes included the aortic remodeling rate and the aortic diameter up to 1 year after surgery.

RESULTS

Subjects consisted of 47 patients (21 in full PETTICOAT group, 26 in the simple entry closure group). The remodeling rate of the abdominal aorta in the full PETTICOAT group was significantly higher than in the simple entry closure group (p < 0.05), while that of the thoracic aorta was comparable between the two groups.

CONCLUSIONS

This study suggests that the full PETTICOAT technique achieves better aortic remodeling compared to entry closure alone, and might lead to less reintervention.

Endograft exclusion of the false lumen restores local hemodynamics in a model of type B aortic dissection

OBJECTIVE

Endovascular intervention in uncomplicated type B dissection has not been shown conclusively to confer benefit on patients. The hemodynamic effect of primary entry tear coverage is not known. Endovascular stent grafts were deployed in a model of aortic dissection with multiple fenestrations to study these effects. It is hypothesized that endograft deployment will lead to restoration of parabolic true lumen flow as well as elimination of false lumen flow and transluminal jets and vortices locally while maintaining distal false lumen canalization.

METHODS

Thoracic stent grafts were placed in silicone models of aortic dissection with a compliant and mobile intimal flap and installed in a flow loop. Pulsatile fluid flow was established with a custom positive displacement pump, and the models were imaged by four-dimensional flow magnetic resonance imaging. Full flow fields were acquired in the models, and velocities were extracted to calculate flow rates, reverse flow indices, and oscillatory shear index, the last two of which are measures of stagnant and disturbed flows.

RESULTS

Complete obliteration of the false lumen was achieved in grafted aorta, with normal parabolic flow profiles in the true lumen (maximal velocity, 30.4 ± 8.4 cm/s). A blind false lumen pouch was created distal to this with low-velocity (5.8 ± 2.7 cm/s) and highly reversed (27.9% ± 13.9% reverse flow index) flows. In distal free false lumen segments, flows were comparable to ungrafted conditions with maximal velocities on the order of 7.0 ± 2.1 cm/s. Visualization studies revealed forward flow in these regions with left-handed vortices from true to false lumen. Shear calculations in free false lumen regions demonstrated reduced oscillatory shear index.

CONCLUSIONS

Per the initial hypothesis, endovascular grafting improved true lumen hemodynamics in the grafted region. Just distally, a prothrombotic flow regimen was noted in the false lumen, yet free false lumen distal to this remained canalized. Clinically, this suggests a need for advancing endovascular intervention beyond sole entry tear coverage to prevent further false lumen canalization through uncovered fenestrations.

Single-center midterm results with the low-profile Zenith Alpha thoracic endovascular stent graft

OBJECTIVE

The analysis of endovascular treatment of thoracic aortic diseases using new low-profile stent grafts in large series is crucial to understanding the durability of these devices. The present study reports the midterm outcomes of a single-center experience using the Zenith Alpha thoracic endovascular stent graft.

METHODS

The outcomes of 270 procedures performed on 262 patients (197 men; mean age, 70.5 ± 9.5 years) using the Zenith Alpha thoracic endovascular stent graft from November 2013 to December 2019 for different thoracic aortic diseases were analyzed. The primary endpoints were 30-day clinical success and midterm (5-year) clinical success. The secondary endpoints were the adverse event rate at 30 days and midterm and access- and device-related complications. The follow-up of surviving patients was performed using computed tomography angiography and office visits at 1, 6, and 12 months and annually thereafter. Kaplan-Meier analysis was performed for overall survival, and freedom from thoracic aortic endovascular repair-related mortality and related reinterventions.

RESULTS

The overall 30-day mortality was 5.2% (2.5% for elective and 30.8% for nonelective cases). Type I endoleaks were identified in six patients. The 30-day primary technical and clinical success rates were 97.8% and 92.6%, respectively. Femoral cutdown was used in 41.1% of cases and percutaneous access in 58.5%. The rate of femoral artery complications after the percutaneous approach was 5.1%, with the need for surgical conversion in 1.9%. The stroke rate was 4.1% (major stroke, 2.2%), and the spinal cord ischemia rate was 3.7% (permanent paraplegia, 0.7%). Of the 248 survivors, 239 complied with the follow-up protocol with adequate computed tomography angiograms available images. Overall follow-up survival was 94.0% at 1 year, 91.6% at 2 years, 88.9% at 3 years, and 88.5% at 5 years. The unplanned secondary endovascular procedure rate was 5.3%. No stent fractures or new-onset type I endoleaks due to stent graft migration were observed in the study cohort.

CONCLUSIONS

The midterm outcomes of this new generation of low-profile devices were satisfactory. The reported low incidence of secondary procedures and the absence of migrations are promising for the long-term durability of these devices.

Role of Endoluminal Techniques in the Management of Acute Type B Aortic Dissection and Intramural Haematoma

Twenty-five years ago, optimal medical management was the mainstay of treatment in acute type B aortic dissection (TBAD) and intramural haematoma (IMH), with surgery being reserved for cases with rupture or critical branch vessel ischaemia. Less invasive endoluminal management of TBAD and IMH has developed rapidly over the past two and a half decades, thus changing the treatment algorithm in these patients. Today the focus has shifted to primary management with a combination of endoluminal intervention and optimal medical treatment. The purpose of this article is to describe the various interventional techniques, discuss the indications for intervention, and present the results in the current literature regarding clinical (rupture, branch vessel ischaemia) as well as morphological response (aortic remodelling), complications, and morbidity/mortality associated with endoluminal intervention.

Endovascular strategies for post-dissection aortic aneurysm (PDAA)

Residual patent false lumen (FL) after type B aortic dissection (TBAD) repair is independently associated with poor long-term survival. Open surgery and endovascular repair result in good clinical outcomes in patients with AD. However, both treatments focus on proximal dissection but not distal dissection. About 13.4–62.5% of these patients present with different degrees of distal aneurysmal dilatation after primary repair. Although open surgery is the first-choice treatment for post-dissection aortic aneurysm (PDAA), there is a need for high technical demand since open surgery is associated with high mortality and morbidity. As a treatment strategy with minimal invasion, endovascular repair shows early benefits and low morbidity. For PDAA, the narrow true lumen (TL), rigid initial flap and branch arteries originating from FL have increased difficulties in operation. The aim of endovascular treatment is to promote FL thrombosis and aortic remodeling. Endovascular repair includes intervention from FL and TL sides. TL intervention techniques (parallel stent-graft, branched and fenestrated stent-graft among others) have been proven to be safe and effective in PDAA. Other FL intervention techniques that have been used in selected patients include FL embolization and candy-plug techniques. This article introduces available endovascular techniques and their outcomes for the treatment of PDAA.

One-Year Single-Center Results of the Multilayer Flow Modulator Stents for the Treatment of Type B Aortic Dissection

Purpose

To report a single-center series of patients with type B aortic dissection treated with the Multilayer Flow Modulator (MFM).

Materials and Methods

Over a 36-month period, 23 patients (median age 53 years; 20 men) with complicated type B aortic dissections (2 acute, 5 subacute, and 16 chronic) were treated with the MFM. Primary endpoints of rupture or dissection-related death, overall mortality, and reintervention were evaluated using the Kaplan-Meier method; estimates for freedom from the endpoints are reported with the 95% confidence interval (CI). Secondary outcomes included technical success, adverse events, and aortic remodeling. Clinical and imaging data were collected preoperatively, directly postoperatively, and annually to 36 months for analysis using computational fluid dynamics (CFD).

Results

Initial technical success was 91.3%. The estimates of the endpoints at 12 months were 100% for freedom from rupture or aortic-related death, 95.7% for freedom from overall mortality, and 91.3% for freedom from reintervention. No device-related neurological or systemic complications occurred, and no additional reinterventions were needed during follow-up. A total of 144 branches overstented by the MFM remained patent. Morphologic analysis of the aortic dissection showed progressive true lumen volume increase (75.9%, p<0.001) with concomitant false lumen volume decrease (42.8%, p<0.001); the CFD analyses showed increased laminar flow.

Conclusion

In the current series, the MFM provided a safe and feasible treatment option for complicated acute, subacute, and chronic type B aortic dissections, with high technical success, low mortality, and active aortic remodeling. Further studies should elucidate the long-term safety of the MFM and its effectiveness in a larger patient cohort.

Floating Stent-Graft as a Support to Bridge an Unfavorable Renal Artery During Postdissection TAAA Repair Using a Multibranched Thoracoabdominal Endograft

Purpose: To report an unusual endovascular technique to manage unfavorable renal artery anatomy encountered in an urgent case of symptomatic postdissection thoracoabdominal aortic aneurysm (TAAA) treated with an off-the-shelf multibranched device. Technique: The technique is demonstrated in a 77-year-old woman who had a history of previous open abdominal aortic aneurysm repair and an emergent procedure to implant a thoracic endograft and an aortic bare Z-stent (PETTICOAT) for acute Stanford type B dissection 7 years prior. The patient presented with a symptomatic, rapidly growing, postdissection TAAA. Endovascular treatment with a Zenith t-Branch was planned. After standard catheterization techniques failed in the left renal artery, a bailout maneuver was utilized to place a "floating" Viabahn stent-graft in the aneurysm sac to create sufficient support to deliver the bridging stent-grafts through the bare stent to the target left renal artery. The procedure was successful in excluding the TAAA and preserving perfusion to all target vessels. No neurological complications occurred. Six-month imaging follow-up confirmed the patency of the bridging stents. Conclusion: Remodeling changes after complex endovascular TAAA procedures often require the use of innovative techniques and materials during secondary procedures. In this case, the presence of a post-PETTICOAT bare aortic stent and hostile target artery anatomy increased the technical difficulty of t-Branch implantation. A "floating" stent-graft could be useful to reach challenging target vessels by providing additional support to bridging stent advancement and deployment.

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.

Improved Remodeling With TEVAR and Distal Bare-Metal Stent in Acute Complicated Type B Dissection

BACKGROUND

The ASSIST (A multicentre Study in Survivors of type B aortic dissection undergoing Stenting) study compared both 1-year outcomes and evolution of true and false lumen (eg, remodeling) in patients with complicated type B aortic dissection subjected to thoracic endovascular aortic repair (TEVAR) with distal true lumen scaffolding by self-expanding nitinol open stent in comparison with TEVAR alone.

METHODS

The ASSIST study was a multicenter prospective single-arm study comparing clinical and imaging data from 39 consecutive patients (59.4 ± 13 years of age) who received TEVAR and the JOTEC E-XL open stent with data from matched control subjects treated with TEVAR alone based on 1:1 propensity score matching. Clinical data were collected by an independent Contract Research Organization (CRO) and computed tomography images were subjected to blinded core-lab analysis.

RESULTS

There were no differences in baseline demographics, clinical profiles, morphological data, procedural details, and in-hospital and 1-year outcomes between groups. Differences emerged with regard to evolution of both true lumen distal to stent graft, false lumen over the entire length of dissection, and remodeling (P < .001). At 1 year, TEVAR with the E-XL stent revealed false lumen thrombosis at the level of celiac trunk in 53.8% vs 17.9% with TEVAR alone (P = .004). Kaplan-Meier survival analysis indicated favorable clinical outcomes with the additional E-XL stent.

CONCLUSIONS

TEVAR for acute complicated type B aortic dissection proved to be safe and promoted remodeling of the stent grafted thoracic aorta. Additional scaffolding of the true lumen distal to TEVAR with a self-expanding stent supported distal true lumen expansion, false lumen regression, and thrombosis, with evidence of improved distal remodeling at 1 year.

Preoperative distal aortic diameter is a significant predictor of late aorta-related events after endovascular repair for chronic type B aortic dissection

OBJECTIVES

Long-term therapeutic effects of thoracic endovascular aortic repair (TEVAR) for chronic type B aortic dissection remain controversial. This study aimed to evaluate the possible predictors of late aortic rupture and re-interventions after TEVAR.

METHODS

We retrospectively reviewed the operative outcomes of 40 patients who underwent TEVAR for chronic type B aortic dissection at Kyushu University Hospital. During a mean follow-up period of 39.2 months, we assessed aortic morphology via computed tomography and then employed a multivariable Cox regression analysis in an attempt to identify the predictors of late aorta-related events.

RESULTS

The early success rate of TEVAR was 100%. During the follow-up, however, three patients died from aortic rupture. Eight patients required aortic re-intervention, including thoraco-abdominal aortic graft replacement, repeated TEVAR, total arch replacement and EVAR. Multivariable Cox regression analysis revealed that the preoperative maximum distal aortic diameter was a significant predictor of late aorta-related events. The cutoff value of the distal aortic diameter was 40 mm. Freedom from aorta-related events was 94.6% at 1 year and 78.3% at 3 years. The survival rate was not significantly different despite the re-intervention.

CONCLUSIONS

TEVAR is an effective treatment for chronic type B dissection, with acceptable mid-term results. The preoperative distal aortic diameter is a significant risk factor for late aorta-related events. When the maximum distal aortic diameter is ≥ 40 mm, a therapeutic strategy should be developed taking into consideration the possible need for aortic re-intervention.

Combined proximal descending aortic endografting plus distal bare metal stenting (PETTICOAT technique) versus conventional proximal descending aortic stent graft repair for complicated type B aortic dissections

BACKGROUND

Aortic dissection is a separation of the aortic wall, caused by blood flowing through a tear in the inner layer of the aorta. Aortic dissection is an infrequent but life-threatening condition. The incidence of aortic dissection is 3 to 6 per 10,000 per year in the Western population, and can be up to 43 per 10,000 per year in the Eastern population. Over 20% of people with an aortic dissection do not reach a hospital alive. After admission, the mortality rates for people with an aortic dissection are between 10% and 20% for those who received endovascular treatment, and between 20% and 30% for those who had open surgery. Thoracic endovascular aortic repair (TEVAR) is the standard endovascular method to treat complicated type B aortic dissection (aortic dissections without involvement of the ascending aorta). Although TEVAR is less invasive than open surgery and has a better long-term aortic remodeling effect than conservative medical treatment, favourable aortic remodelling is usually limited to the thoracic aortic segment. TEVAR cannot be extended into the abdominal aorta because it could cover the ostia of the reno-visceral arteries. Thus, the abdominal aorta is still at risk of progressive aneurysmal degeneration. The PETTICOAT (provisional extension to induce complete attachment) technique, with proximal endograft and distal bare metal stent, was proposed in 2006 to address this issue. The concept of this technique was to implant a distal bare metal stent into the aortic true lumen, distal to the proximal endograft, to stabilize the distal collapsed intimal flap, while allowing blood flow to reno-visceral arteries. Therefore, the PETTICOAT technique was considered to be related to a more extensive aortic remodelling for people with type B aortic dissection, especially in the area of the abdominal aorta. However, it is still unclear whether the PETTICOAT technique is superior to standard TEVAR.

OBJECTIVES

To assess the effects of combined proximal descending aortic endografting plus distal bare metal stenting versus conventional proximal descending aortic stent graft repair for treating complicated type B aortic dissections.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases, and the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 5 November 2018. We also undertook reference checking and citation searching to identify additional studies.

SELECTION CRITERIA

We considered all randomised controlled trials which compared the outcome of complicated type B aortic dissection, when treated by combined proximal descending aortic endografting plus distal bare metal stenting (PETTICOAT technique) versus conventional proximal descending aortic stent graft repair.

DATA COLLECTION AND ANALYSIS

Two independent review authors assessed all references identified by the Cochrane Vascular Information Specialist. We planned to undertake data collection and analysis in accordance with recommendations described in the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

We found no trials that met the inclusion criteria for this review.

AUTHORS' CONCLUSIONS

We identified no randomised controlled trials and therefore cannot draw any definite conclusion on this topic. Evidence from non-randomised studies appears to be favourable in the short-term, for combined proximal descending aortic endografting plus distal bare metal stenting (PETTICOAT technique) to solve the problem of unfavourable distal aortic remodeling. Randomised controlled trials are warranted to provide solid evidence on this topic. Evidence from cohort studies with large sample sizes would also be helpful in guiding clinical practice.

Expanded Petticoat technique to promote the reduction of contrasted false lumen volume in patients with chronic type B aortic dissection

OBJECTIVE

This study examined the outcomes of our novel concept of expanded provisional extension to induce complete attachment strategy (Petticoat) for safety, durability, and remodeling of chronic type B dissections.

METHODS

Twenty patients with chronic type B aortic dissection with aneurysmal degeneration qualified for an expanded Petticoat strategy (stent graft in the thoracic, plus additional distal bare stent into the abdominal and infrarenal aorta, followed by parallel stent grafts into common iliac arteries). Computed tomography was performed preoperatively and at 1, 6, and 12 months after surgery.

RESULTS

The primary technical success was 100%. The 30-day mortality rate was 0%. At 12 months, favorable aortic remodeling and complete false lumen (FL) thrombosis were noted as 100% in the thoracic and infrarenal aorta. The volume of contrast-enhanced FL decreased from 186 ± 75.4 mL all along the dissection preoperatively (range, 70-360 mL), to 6.32 ± 5.4 mL postoperatively (range, 0.0-19.6 mL) and was only observed in the visceral aorta (P = .000089). Despite persistent flow in a small area of the FL, the maximal aortic size was stable in follow-up. Neither paraplegia nor visceral branch occlusion were noted in the follow-up.

CONCLUSIONS

The treatment of aortic dissections with an expanded Petticoat strategy seems to be safe and offers good early results. It significantly reduced the volume of contrast enhanced FL. Further investigation of any subsequent results will be necessary.

Endovascular Management of Isolated Spontaneous Superior Mesenteric Artery Dissecting Aneurysm

Objectives

The aim is to present the technique of successful management of a superior mesenteric artery (SMA) dissecting aneurysm by a purely endovascular approach.

Methods

This was a single centre case report.

Results

Isolated spontaneous SMA dissecting aneurysm is rare, and previously was usually treated by an open or hybrid approach. This is a single centre case report of the successful management of a SMA dissecting aneurysm by a purely endovascular approach.

Conclusions

A pure endovascular approach is feasible and effective in the management of isolated SMA dissecting aneurysm, which is a rare but life threatening condition.

•

Isolated spontaneous superior mesenteric artery (SMA) dissecting aneurysm is rare.

•

SMA dissecting aneurysm is life-threatening.

•

SMA dissecting aneurysm was previously usually treated by open or hybrid approach.

•

Management of SMA dissecting aneurysm with pure endovascular approach is effective.

Thoracic endovascular aortic repair with stent grafts alone or with a composite device design in patients with acute type B aortic dissection in the setting of malperfusion

OBJECTIVE

The objective of this study was to compare short-term outcomes in patients who underwent thoracic endovascular aortic repair (TEVAR) with stent grafts alone or with a composite device design (stent graft plus bare-metal aortic stent) for acute type B aortic dissection in the setting of malperfusion.

METHODS

This retrospective analysis included patients with acute (≤14 days of symptom onset) complicated type B dissection in the setting of malperfusion who were treated with stent grafts alone (TEVAR cohort) at two European institutions vs those who underwent TEVAR with a composite device design (Cook Medical, Bloomington, Ind) in the investigational STABLE I feasibility study and STABLE II pivotal study (STABLE cohort). Preoperative characteristics and 30-day outcomes (including mortality, malperfusion-related mortality, morbidity, and secondary interventions) were compared between the two groups.

RESULTS

The TEVAR cohort (41 patients; mean age, 58.8 ± 12.7 years; 78.0% male) and the STABLE cohort (84 patients; mean age, 57.8 ± 11.7 years; 71.4% male) were largely similar in preoperative medical characteristics, with more STABLE patients presenting with a history of hypertension (79.8% vs 58.5%; P = .018). The TEVAR and STABLE groups had similar lengths of dissection (451.8 ± 112.7 mm vs 411.8 ± 116.4 mm; P = .10) and similar proximal and distal extent of dissection. At presentation, the two groups exhibited comparable organ system involvement in malperfusion: renal (53.7% TEVAR, 57.1% STABLE), gastrointestinal (41.5% TEVAR, 44.0% STABLE), lower extremities (34.1% TEVAR, 52.4% STABLE), and spinal cord (9.8% TEVAR, 2.4% STABLE). The 30-day rate of all-cause mortality was 17.1% (7/41) in the TEVAR group and 8.3% (7/84) in the STABLE group (P = .22). The 30-day rate of malperfusion-related mortality (deaths from bowel/mesenteric ischemia or multiple organ failure) was 12% (5/41) in the TEVAR group and 2.4% (2/84) in the STABLE group (P = .038). The 30-day morbidity, for the TEVAR and STABLE groups, respectively, included bowel ischemia (9.8% [4/41] vs 2.4% [2/84]; P = .09), renal failure requiring dialysis (7.3% [3/41] vs 9.5% [8/84]; P > .99), paraplegia or paraparesis (4.9% [2/41] vs 3.6% [3/84]; P = .66), and stroke (2.4% [1/41] vs 10.7% [9/84]; P = .16). The occurrence of 30-day secondary intervention was similar in the TEVAR and STABLE groups (7.3% [3/41] vs 7.1% [6/84]; P > .99). True lumen expansion in the abdominal aorta was significantly greater in the STABLE group.

CONCLUSIONS

In patients with acute type B aortic dissection in the setting of branch vessel malperfusion, the use of a composite device with proximal stent grafts and distal bare aortic stent appeared to result in lower malperfusion-related mortality than the use of stent grafts alone. The 30-day rates of morbidity and secondary interventions were similar between the groups.