Endovascular repair of type B aortic dissection: long-term results of the randomized investigation of stent grafts in aortic dissection trial

Interleukin-3 is required for thoracic aneurysm and dissection in a mouse model

The pathogenesis of thoracic aortic aneurysm and dissection (TAAD) is complex and incompletely understood. The hallmarks of the disease process are aortic inflammatory cell infiltration and protease mediated elastic fiber disruption. In a study recently published in Clinical Science (2018) 132 (6), 655–668), Liu et al. explore the mechanism through which aortic vascular smooth cells and macrophages participate in TAAD using a mouse model. The authors propose that interleukin-3 (IL-3) released from aortic vascular smooth cells is central to the disease process. IL-3 stimulated matrix metalloproteinase 12 (MMP12) release from macrophages via mitogen activated protein kinase pathways. MMP12 is a protease known to be involved in both aortic aneurysm and dissection. IL-3 knockout mice had significantly reduced aortic wall MMP12, and reduced protease activity. This was associated with protection against TAAD.

Short term outcome of thoracic endovascular aortic repair in patients with thoracic aortic diseases

AIM AND BACKGROUND

Open surgical repair for thoracic aortic diseases is associated with a high perioperative mortality and morbidity. Most of type B aortic dissections are uncomplicated and are medically treated which carries a high mortality rate. Thoracic endovascular aortic repair is the first-line therapy for isolated aneurysms of the descending aorta and complicated type B aortic dissection. The aim of this study is to test the safety of early thoracic endovascular aortic repair in patients with uncomplicated type B aortic dissection and patients with thoracic aortic aneurysms.

METHODS

A total of 30 patients (24 men and 6 females; mean age 59 ± 8 years) with uncomplicated type B aortic dissection and descending thoracic aortic aneurysm who underwent endovascular aortic repair in National Heart Institute and Cairo University hospitals were followed up. Clinical follow-up data was done at one, three and twelve months thereafter. Clinical follow-up events included death, neurological deficits, symptoms of chronic mal-perfusion syndrome and secondary intervention. Multi-slice computed tomography was performed at three and six months after intervention.

RESULTS

Of the 30 patients, 24 patients had aortic dissection, and 6 patients had an aortic aneurysm. 7 patients underwent hybrid technique and the rest underwent the basic endovascular technique in whom success rate was 100%. Two patients developed type I endoleak, however both improved after short term follow up. The total mortality rate was 10% throughout the follow-up. Both death and endoleak occurred in subacute and chronic cases, while using TEVAR in acute AD and aneurysm showed no side effects. Early thoracic endovascular aortic repair showed better results and less complications.

CONCLUSION

Along with medical treatment, early thoracic endovascular aortic repair in uncomplicated type B aortic dissections and thoracic aortic aneurysms is associated with better outcome.

Radical treatment of primary type B aortic dissection or after thoracic endovascular aortic repair to manage disseminated intravascular coagulation

Disseminated intravascular coagulation (DIC) secondary to type B aortic dissection is an unusual and fatal complication that has not been fully investigated. The aim of our study is to report a novel endovascular technique excluding all tears to manage DIC. From April 2017 to October 2017, we performed 2 cases of DIC complicated to type B aortic dissection using this novel radical endovascular repair technique. Clinical data of patients were collected and technical details were presented. These two cases were successfully treated with novel radical endovascular repair technique. DIC was managed and FL thrombosis was formed in these two patients. Follow-up at 6 months revealed no recurrent DIC and a stable aortic diameter with complete FL thrombosis. This endovascular repair technique that excluding all the tears is a feasible approach to prevents continuous coagulation components consumption and thus to manage DIC effectively.

Open Replacement of the Thoracoabdominal Aorta: Short- and Long-term Outcomes at a Single Institution

Background  Despite much progress in the surgical and endovascular treatment of thoracoabdominal aortic diseases (TAADs), there is no consensus regarding the optimal approach to minimize operative mortality and end-organ dysfunction. We report our experience in the past 16 years treating TAAD by open surgery. Methods  A retrospective review of all TAAD patients who underwent an open repair since January 2000 was performed. The primary endpoints included early morbidity and mortality, and the secondary endpoints were overall death and rate of aortic reintervention. Results  There were 112 patients treated by open surgery for TAAD. Mean age was 66 ± 10 years and 61 (54%) were male. Seventy-seven (69%) patients had aneurysmal degeneration without aortic dissection and the remaining 35 (31%) had a concomitant aortic dissection. There were 12 deaths (10.7%) and they were equally distributed between the aneurysm and dissection groups ( p  = 0.8). The mortality for elective surgery was 3.2% (2/61). The rate of permanent paraplegia and stroke were each 2.6% (3/112). The rate of cerebrovascular accident was significantly higher in the dissection group (8.5% vs. 1.2%, p  = 0.05). The survival at 1, 5, and 10 years was 80.6, 56.1, and 32.7%, respectively. Conclusion  Our data confirm that open replacement of the thoracoabdominal aorta can be performed in expert centers quite safely. Different aortic pathologies (degenerative aneurysm vs. dissection) do not influence the short- and long-term outcomes. Open surgery should still be considered the standard in the management of TAAD.

Thoracic Endovascular Aortic Repair versus Best Medical Treatment for High-Risk Type B Intramural Hematoma: A Systematic Review of Clinical Studies

BACKGROUND

To date, thoracic endovascular aortic repair (TEVAR) for type B aortic dissection is favorable, but TEVAR for type B intramural hematoma (IMH) remains uncertain. There are numerous clinical (e.g., refractory pain) and radiologic (e.g., IMH thickness) factors that are reported to be associated with IMH progression, challenging the treatment for high-risk type B IMH with high risk factors in clinical practice.

OBJECTIVE

The objective of the study was to perform a systematic review of clinical studies to investigate outcomes of TEVAR + best medical treatment (BMT) and BMT in the treatment of high-risk type B IMH.

METHODS

The online databases of PubMed, MEDLINE, EMBASE, CNKI, Google Scholar, and Cochrane as well as some journals majoring in endovascular surgery and interventional therapy were searched on September 1, 2017. Observational studies that reported the effect of TEVAR and BMT on type B IMH were included. Two independent reviewers performed methodological assessment and data extraction. Random and fixed effects models were used to calculate pooled effect size estimates. A sensitivity analysis was also carried out.

RESULTS

In all 6 included studies, the total number of patients with type B IMH was 237 and 123 patients received TEVAR + BMT. There was a significantly higher IMH regression rate among patients undergoing TEVAR + BMT compared with BMT (odds ratios [OR] 10.0, 95% confidence interval [CI] 3.43-29.4). There were a significantly lower IMH progress rate and aortic-related death rate among patients undergoing TEVAR + BMT compared with BMT (OR 0.239, 95% CI 0.075-0.758; OR 0.248, 95% CI 0.085-0.725). When the study of Ye K et al. was excluded, the results showed no statistically significant differences.

CONCLUSIONS

Combined data from the present study demonstrate that TEVAR + BMT results in significantly higher IMH regression rate, lower IMH progression, and lower aortic-related death rate compared with BMT in high-risk type B IMH patients.

Thoracic endovascular aortic repair for uncomplicated type B aortic dissection

PURPOSE OF REVIEW

Type B aortic dissection has largely been regarded as the nice dissection with regard to its natural course, especially when compared with type A aortic dissection. However, a more thorough look into the natural course of the disease has shown that a high number of patients with type B aortic dissection will experience complications and will require therapy, sooner or later.

RECENT FINDINGS

Reasons and timepoints are different, being malperfusion, contained rupture and retrograde propagation of the disease into the aortic arch or into the ascending aorta in the early phase and being mainly aneurysmal formation in the chronic phase of the disease.

SUMMARY

This article provides the interested reader with detailed knowledge regarding the natural course of the disease and is meant as a companion to anticipate the right timepoint for therapy and finally as a guide to do the right things when advancing to treatment.

Endovascular Treatment of Various Aortic Pathologies: Review of the Latest Data and Technologies

The technologies and innovations applicable to endovascular treatment for complex aortic pathologies have progressed rapidly over the last two decades. Although the initial outcomes of an endovascular aortic repair have been excellent, as long-term data became available, complications including endoleaks, endograft migration, and endograft infection have become apparent and are of concern. Previously, the indication for endovascular therapy was restricted to descending thoracic aortic aneurysms and abdominal aortic aneurysms. However, its indication has expanded along with the improvement of techniques and devices, and currently, it has become possible to treat pararenal aortic aneurysms and Crawford type 4 thoracoabdominal aortic aneurysm (TAAA) using the off-the-shelf devices. Additionally, custom-made devices allow for the treatment of arch or more extensive TAAAs. Endovascular treatment is applied not only to aneurysms but also to acute/chronic dissections. However, long-term outcomes are still unclear. This article provides an overview of available devices and the results of endovascular treatment for various aortic pathologies.

Endovascular stent-induced alterations in host artery mechanical environments and their roles in stent restenosis and late thrombosis

Cardiovascular stent restenosis remains a major challenge in interventional treatment of cardiovascular occlusive disease. Although the changes in arterial mechanical environment due to stent implantation are the main causes of the initiation of restenosis and thrombosis, the mechanisms that cause this initiation are still not fully understood. In this article, we reviewed the studies on the issue of stent-induced alterations in arterial mechanical environment and discussed their roles in stent restenosis and late thrombosis from three aspects: (i) the interaction of the stent with host blood vessel, involve the response of vascular wall, the mechanism of mechanical signal transmission, the process of re-endothelialization and late thrombosis; (ii) the changes of hemodynamics in the lumen of the vascular segment and (iii) the changes of mechanical microenvironment within the vascular segment wall due to stent implantation. This review has summarized and analyzed current work in order to better solve the two main problems after stent implantation, namely in stent restenosis and late thrombosis, meanwhile propose the deficiencies of current work for future reference.

Thoracic endovascular aortic repair to treat uncomplicated Stanford type B aortic dissection: The surgeon's dilemma to preventing future complications

Uncomplicated type B aortic dissections have traditionally been managed non-operatively with aggressive blood pressure control. However, the best medical treatment is associated with a considerable risk of disease progression to complicated dissection or aneurysmal degeneration of the affected aortic segment. Thoracic endovascular aortic repair could prevent long-term complications but, because the dissected aorta is vulnerable, it is a high-risk procedure performed in asymptomatic patient. Therefore, endovascular treatment is not a solution for all patients and it should be performed only in the subgroup prone to developing progression of the disease and future complications. A number of studies have suggested several prognostic factors of early or late adverse events such as the patency of the false lumen in the follow-up, an initial aortic diameter ≥4 cm with a patent false lumen, an initial false lumen diameter ≥22 mm in the proximal descending aorta, visceral involvement and recurrent or refractory pain or hypertension. Partial false lumen thrombosis and a proximal entry tear size >10 mm have also been suggested to be associated with an increased rate of aortic growth. We need randomised trials focused on these prognostic factors to reach level 1, class A recommendation for the optimal timing of intervention. Meanwhile, we have to discuss with the patient the pro and cons of this prophylactic, low-invasive but high-risk treatment to personalise medical care and provide the optimal risk-to-benefit ratio.

Type B aortic dissection: new perspectives

Background

Stanford type B aortic dissection is one of the aortic catastrophes with a high mortality and morbidity that needs immediate or delayed treatment, either surgically or endovascularly. This comprehensive review article addresses the current status of open, endovascular and hybrid treatment options for type B aortic dissections with the focus on new therapeutic perspectives.

Methods

Evaluation of currently available evidence based on randomized and registry data and personal experience.

Results

All type B dissections require prompt medical treatment to prevent aortic rupture. Acute complicated dissections are nowadays treated by endografting to reroute blood flow into the true lumen and promote false lumen thrombosis and future aortic remodeling. In acute uncomplicated situations the position of endografting is less clear and should be further delineated; however, on the long run also in these situations endografting might be protective for future aortic catastrophes in certain patient categories. In the chronic dissection with aneurysm formation of the descending thoracic and/or thoracoabdominal aorta, especially in connective tissue disorders, open surgery offers nowadays the best immediate results with long durability. Thoracic endografting plays only a minor role in these circumstances but branched and fenestrated endografting are very promising techniques. Hybrid techniques can offer the solution for high risk patients that are not suitable for open surgery.

Conclusions

Emergent thoracic endografting is the golden standard for all complicated type B dissections while uncomplicated patients with high-risk features might benefit from endovascular repair. Open surgery is limited for chronic post dissection aneurysms. Aortic surveillance is of paramount importance in all situations.

Intravascular ultrasound assisted sizing in thoracic endovascular aortic repair improves aortic remodeling in Type B aortic dissection

The precise sizing of the stent graft in thoracic endovascular aortic repair (TEVAR) affects aortic remodeling and hence, further outcome. Covering the proximal entry tear is essential for successful treatment of Type B aortic dissection. Intravascular ultrasound (IVUS) enables real-time aortic diameter assessment, and is especially useful when computed tomography (CT) image quality is poor. IVUS, however, is not routinely utilized due to cost inefficiency. We investigated the impact of IVUS-assisted stent graft sizing on aortic remodeling in TEVAR. In this single-center retrospective study we evaluated patients with Type B aortic dissection undergoing both CT and IVUS before TEVAR. We assessed the aortic diameter at the level of the left subclavian artery via both methods before stent implantation and analyzed due to which method the implanted stent graft was chosen, retrospectively. To determine the degrees of aortic remodeling involved, we evaluated true lumen and false lumen diameters, and total aortic remodeling in CT. We analyzed 45 patients with Type B aortic dissection undergoing TEVAR. The mean ages were 66.9±10.0 years fo0072 IVUS (n = 20) and 62.3±14.2 years for CT-assisted TEVAR (n = 25; p = 0.226). The follow-up time for both groups did not differ between the two groups (IVUS: 22.9±23.1 months, CT: 25.6±23.0 months; p = 0.700). While both methods were associated with advantages regarding aortic remodeling, IVUS-assisted sizing yielded a greater increase in true lumen (30.4±6.2 vs. 25.6±5.3; p = 0.008) and reductions in false lumen (14.4±8.5 vs. 23.9±9.3; p = 0.001) and total aortic diameter (35.5±6.0 vs. 39.9±8.1; p = 0.045). IVUS-guided stent graft sizing in Type B aortic dissection shows beneficial effects on aortic remodeling and might be of additional advantage in aortic diseases, especially when CT image quality is poor.

Suppressive effect of pitavastatin on aortic arch dilatation in acute stanford type B aortic dissection: analysis of STANP trial

OBJECTIVES

Medical therapy for patients with uncomplicated acute type B aortic dissection (ABAD) is essentially accepted for its excellent early outcome; however, long-term outcomes have not been satisfactory due to aorta-related complications. This trial was performed to investigate the efficacy of a statin as an additive that may enhance the effectiveness of conventional medical treatment in patients with ABAD.

METHODS

This was a multi-center, prospective, and randomized comparative investigation of patients with uncomplicated ABAD. Fifty patients with ABAD compatible with inclusion criteria were randomly assigned to two groups and then received administration of pitavastatin (group P) or not (group C). We followed up the patients for 1 year from study onset.

RESULTS

Two patients demised during the follow-up period (both were in group C). In addition, aorta-related interventions were performed in two patients (entry closure for aortic dissection by endovascular repair in one patient in each group). Aortic arch diameters at 1 year in group P tended to be smaller than in group C (P = 0.17), and the rate of change of the aortic arch diameters from onset to 1 year was significantly lower in group P (P = 0.046). Multivariate analysis identified patency of the false lumen was detected as a risk factor for aortic arch dilatation (P = 0.02), and pitavastatin intake was a negative risk factor (P = 0.03).

CONCLUSIONS

Pitavastatin treatment, in addition to the standard antihypertensive therapy, may have a suppressive effect on aortic arch dilatation in patients with ABAD.

Endovascular management of acute aortic dissection

Acute dissection of the thoracic aorta is a potentially life-threatening condition which requires collaborative treatment from multiple specialties for optimal patient outcomes. Dissections involving the ascending aorta and aortic arch have traditionally been managed entirely by surgery, while dissections beyond the arch vessels have most commonly been relegated to medical management. This algorithm has been undergoing a paradigm shift over the past two decades due to improvements in stent graft technology, better understanding of the hemodynamic interactions of the true and false lumen and their influence on organ and limb perfusion, and improvements in medical management and long term surveillance for dissection-related complications. This manuscript includes a brief discussion of the pathogenesis and etiology of dissection, followed by an in-depth review of the medical and endovascular techniques utilized to treat patients afflicted by this condition.

Distal re-entry closure with neobranching technique after thoracic endovascular aortic repair of Type B aortic dissection

Retrograde false-lumen flow after thoracic endovascular aortic repair of Type B aortic dissection occurs occasionally and may have a negative impact on aortic remodelling and even prevent the decompression of the false lumen. A 67-year-old man with a Type B aortic dissection underwent thoracic endovascular aortic repair for severe compression of the true lumen and visceral malperfusion 7 weeks after the onset. Intraoperative angiography revealed proximal entry tear closure, but the false-lumen flow increased because of retrograde flow through the re-entry tear. Additional intervention including re-entry tear closure was performed with a neobranching technique with covered stent placement in the visceral artery from the aortic true lumen through the distal re-entry tear. We report a case of Type B aortic dissection and discuss the surgical techniques used.

The incidence of delayed complications in acute type B aortic dissections is underestimated

OBJECTIVE

Acute type B aortic dissections (TBADs) can have immediate or delayed complications within the first 2 weeks. Because the majority of clinical series retrospectively categorized TBAD, the incidence and outcome of delayed complications in initially uncomplicated TBAD within the first 14 days are not well described.

METHODS

We retrospectively analyzed 86 patients (78% male; age, 62.5 ± 13 years) with acute TBAD treated consecutively between January 2004 and May 2016 at a tertiary referral center. All TBADs were confirmed by computed tomography angiography (CTA) on admission, after 2 to 5 days, and after 10 to 14 days. Study end points were the incidence of immediate and delayed complications (aortic rupture, malperfusion, rapid aortic expansion >4 mm, pain or hypertension resistant to medical therapy) and in-hospital mortality. In addition, we looked at CTA-detected morphometric variables (maximum diameters of descending aorta, false lumen [FL], and primary entry tear; number of intimal tears; FL configuration; true lumen collapse; course of the dissection) and their association with delayed complications. Finally, we assessed treatment modalities and clinical outcomes.

RESULTS

Of all TBADs, 22 (26%) presented with immediate complications (rupture, n = 11); 64 patients (74%) were initially assessed as having uncomplicated TBAD. Of these 64 patients, 24 (28% of all 86) suffered from delayed complications (malperfusion, n = 10; aortic rupture, n = 3; early expansion >4 mm, n = 8; refractory pain, n = 2; uncontrollable hypertension, n = 1) at a median interval of 7.1 (2-14) days after symptom onset. During the first 14 days, 40 patients (46%) remained uncomplicated. The CTA analysis revealed a significant association of initial thoracic aortic diameter (P = .009), size of the primary entry tear (P = .018), true lumen collapse (P = .019), and partially thrombosed FL (P = .019) with the occurrence of delayed complications within the first 14 days. Of the patients with delayed complications, 87.5% underwent surgery (90% thoracic endovascular aortic repair, 10% peripheral revascularization); 12.5% in this group died following aortic rupture before they received surgical repair. The mortality of patients with delayed complicated TBAD was significantly higher compared with those who remained uncomplicated within the 14-day period (12.5% vs 0%; P = .0221).

CONCLUSIONS

Delayed complications in initially uncomplicated acute TBAD are not infrequent. Morphologic variables like maximum diameter of the descending aorta, primary entry tear, true lumen collapse, and partially thrombosed FL were associated with an increased risk of delayed complications in initially uncomplicated TBAD. Future clinical research must verify the predictive role of clinical and morphologic variables in the acute phase, particularly with regard to a possible early surgical treatment to prevent a fatal outcome.

[Aortic diseases : Modern diagnostic and therapeutic strategies]

Aortic diseases include not only the thoracic but also the abdominal part of the aorta. In the etiology cardiovascular risk factors, such as hypertension, smoking and hyperlipoproteinemia play a major role, but more and more genetic diseases with familiar predisposition are being identified. Even large aneurysms remain asymptomatic as long as other organs in the neighborhood are not damaged and no acute aortic event occurs including aortic dissection, intramural hematoma, penetrating aortic ulcer, and traumatic aortic injury. Standardized algorithms allow precise and rapid diagnosis for initiating medicinal therapy or operative and/or endovascular interventions (thoracic/endovascular aortic repair, TEVAR/EVAR) in this emergency situation. Specialized aortic centers are recommended to form localized regional networks.

Conservative management versus endovascular or open surgery in the spectrum of type B aortic dissection

Background

Type B aortic dissection is a life-threatening acute aortic condition often with acute ischemic signs or symptoms. With initial management focusing on alleviating malperfusion and pain, and avoiding propagation of dissection or rupture both systolic blood and pulse pressure should be reduced initially by an aggressive medical approach. In the setting of persistent signs of complications endovascular strategies have replaced open surgery and led to a fourfold increase in early survival and better long-term outcomes.

Methods

An electronic health database search was performed on articles published between January 2006 and July 2017. Publications were included in this review if (I) the index aortic pathology was type B aortic (distal) dissection; (II) when medical management, open surgical replacement or thoracic endovascular aortic repair were among those options; (III) when at least one of all basic outcome criteria such as survival, spinal cord ischemia and cerebrovascular accident was reported; (IV) when ≥15 serial patients were included. A total of 62 studies were eligible and analysed.

Results

Our manuscript has summarized data collected over 12 years on management specific outcomes in the setting of distal aortic dissection and provides an up-to-date interpretation of the published evidence. For complicated cases, treated acutely, the 30-day or in-hospital mortality was 7.3% when managed by endovascular means, whereas the pooled rate for 30-day or in-hospital mortality was 19.0% when subjected to open repair. For acute uncomplicated type B dissection usually treated with blood pressure lowering medications, the pooled 30-day or in-hospital mortality rate was 2.4%. Survival rates at 5 years averaged at 60% (40% mortality). Freedom from any aortic event ranged from 34.0% to 83.9%, underlining an inherent risk of progression and late complications. For chronic complicated type B dissection, the rates of stroke, paraplegia and operative mortality following endovascular repair ranged from 5% to 13%, 2% to 13% and 2 to 13%, respectively, while 5-year survival rates after open repair ranged from 60% to 90%. In chronic uncomplicated type B dissection almost 90% of patients survive initial hospitalization and were subjected to medical management with a 5-year survival of 50-80%. However, up to 20-55% of medically treated patients develop aneurysmal degeneration after 5 years with an unknown risk of rupture.

Conclusions

Currently, the less invasive strategy of endovascular repair (as compared to open surgery) provides improved 30-day or in-hospital survival in the setting of complicated acute type B aortic dissection and may seek broad application. Open surgical aortic reconstruction should be left to experienced aortic centres if endovascular management is not an option.

Outcomes of Thoracic Endovascular Aortic Repair for Acute Type B Dissection in Patients With Intractable Pain or Refractory Hypertension

PURPOSE

To compare uncomplicated acute type B aortic dissection (UATBAD) patients with intractable pain/refractory hypertension treated with thoracic endovascular aortic repair (TEVAR) to UATBAD subjects without these features receiving best medical therapy (BMT).

METHODS

Interrogation of the hospital database identified 101 consecutive UATBAD patients admitted between January 2011 and December 2014. Of these, 74 patients (mean age 62±13 years; 44 men) were treated with BMT; the other 27 UATBAD patients (mean age 63±13 years; 17 men) were subsequently treated with TEVAR for intractable pain (24, 89%) and/or refractory hypertension (3, 11%) at a mean 2.4±3.3 days (median 1, range 0-12) after admission. Mixed models were employed to determine differences in centerline measured aortic remodeling. Propensity analysis was employed to mitigate selection bias. Kaplan-Meier methodology was used to estimate reintervention and survival.

RESULTS

The groups were well matched; there was no difference in demographics, comorbidities, or proportion with visceral involvement (70% for TEVAR vs 86% for BMT, p=0.08). There was no significant difference in length of stay (9.6±6.3 for TEVAR vs 10.3±7.8 for BMT, p=0.3), complications (19% for TEVAR vs 24% for BMT, p=0.6), or 30-day mortality (0 for TEVAR vs 7% for BMT, p=0.1). One (4%) TEVAR patient experienced retrograde dissection. BMT resulted in greater mean increase in discharge antihypertensive medications (1.7±1.9 vs 0.7±1.7 for TEVAR, p=0.03), but there was no difference in narcotic utilization. Mean follow-up was greater in the TEVAR group (17.9±16.0 months) compared with BMT patients (11.5±10.8 months, p=0.05). TEVAR significantly improved rates of aortic diameter change (1.5% vs 12.9% for BMT, p=0.007), complete false lumen thrombosis (41% vs 11% for BMT, p=0.004), and true lumen expansion (85% vs 7% for BMT, p<0.01). However, there was no difference in reintervention (25.9% for TEVAR vs 23% for BMT, p=0.2) or survival (log-rank p=0.8).

CONCLUSION

TEVAR for UATBAD with intractable pain/refractory hypertension is safe but offers no short-term outcome advantage when compared to UATBAD patients without these features receiving BMT. A significant improvement in aortic remodeling was identified after TEVAR. The potential long-term reintervention and aorta-related mortality benefits of this favorable remodeling have yet to be defined and randomized trials are warranted.

[Acute aortic syndromes]

Acute aortic syndromes include aortic dissections, intramural hematomas, penetrating ulcers, ruptured or contained ruptured aortic aneurysms. In presence of acute thoracic or dorsal pain, elevated D-Dimers and if acute coronary artery syndrome has been ruled out, additional imaging should be performed to detect acute aortic pathologies. Acute type A dissections involve the ascending aorta. Emergent open repair is the preferred treatment. Acute type B dissections involve the thoracic descending aorta. Endovascular treatment using thoracic stent grafts is indicated in complicated cases (malperfusion, rupture, uncontrolled hypertension) or in cases where risk factors of aortic degeneration are identified. Regarding ruptured abdominal aortic aneurysms, optimization techniques recently led to a reduced postoperative mortality. They include adequate treatment of abdominal compartment syndrome, use of aortic stent grafts, endovascular balloon occlusion and permissive hypotension. Symptomatic complex aneurysms encompass renal and visceral arteries. Nowadays, they can be treated in an urgent setting using new endovascular techniques, such as "off-the shelf" branched stent grafts, parallel techniques, home made or in situ fenestrations of standard stent grafts.

[Endovascular repair of the thoracic aorta]

Degenerative aneurysms of the thoracic aorta are increasing in prevalence. The recognition of the decreased morbidity of this approach compared with open repair was readily apparent, as it avoided left thoracotomy, aortic cross-clamping, and left heart bypass. Repair of isolated descending thoracic aortic aneurysms using stent grafts was introduced in 1995, and in an anatomically suitable subgroup of patients with thoracic aortic aneurysm, repair with endovascular stent graft provides favorable outcomes, with decreased perioperative morbidity and mortality relative to open repair. The cornerstones of successful thoracic endovascular aneurysm repair are appropriate patient selection, thorough preprocedural planning, and cautious procedural execution. Since then, TEVAR is increasingly being used for other aortic pathologies such as complicated type B dissection, traumatic aortic transection, and aneurysmal disease extending into the arch or visceral segment, requiring debranching procedures.

Conceptualizing treatment of uncomplicated type B dissection using the IDEAL framework

OBJECTIVE

The objective of this study was to introduce a new framework, called IDEAL (idea, development, exploration, assessment, and long-term study), to guide physicians, investigators, and regulatory agencies through the life cycle of device development and procedural refinement.

METHODS

This review describes the IDEAL framework and illustrates its application for treatment of uncomplicated type B dissection (uTBD) as an example of this process.

RESULTS

Components of IDEAL are summarized and applied to devices used to treat uTBD. Treatment of uTBD is currently in the exploration phase, with concurrent assessment and long-term study being facilitated by detailed registries.

CONCLUSIONS

The application of IDEAL to the development and monitoring of technologies standardizes the nomenclature, facilitates evidence-based practice, and enhances the innovation process.

Endovascular treatment of acute and chronic isolated abdominal aortic dissection

Objective

To discuss the strategies and clinical outcomes of endovascular aortic repair (EVAR) for acute and chronic isolated abdominal aortic dissection (IAAD).

Methods

From January 2012 to June 2017, 33 patients with IAAD were retrospectively reviewed. Patients were classified into acute and chronic groups based on the time to EVAR from IAAD onset (acute: ≤90 days; chronic: >90 days). Patient demographics, clinical parameters, procedural factors, and clinical outcomes were evaluated and compared between the two groups.

Results

Among 33 patients, 21 were diagnosed with acute IAAD and 12 were diagnosed with chronic IAAD. All patients underwent EVAR, and no significant difference in EVAR-related procedural factors was observed between the two groups. The primary technical success rate in all patients was 100%. The overall survival rate in the chronic group was lower than that in the acute group, but the difference was not statistically significant ( P = 0.186). However, the reintervention-free survival rate in the chronic group was significantly lower than that in the acute group ( P = 0.039). Significant enlargement of the true lumen (TL) and regression of the false lumen (FL) and maximal aortic diameter were observed in all patients after EVAR ( P < 0.05). The mean diameter of the TL in the acute group increased significantly more than that in the chronic group (14 ± 3 mm vs. 11 ± 3 mm, P = 0.040). A significant difference was not observed in the regression of the FL ( P = 0.628) or maximal aortic diameter ( P = 0.319) between the two groups.

Conclusion

EVAR continues to be a safe therapeutic approach with a high technical success rate and favorable clinical outcomes. The clinical outcomes and aortic remodeling in the chronic group seem to be poorer than those in the acute group.

Natural history of the proximal aorta in patients with descending thoracic aortic disease

OBJECTIVE

This study investigated the growth and behavior of the ascending aorta in patients with descending thoracic aortic disease.

METHODS

We examined 200 patients with descending thoracic aortic disease including acute type B dissection (n = 95), chronic type B dissection (n = 38), intramural hematoma (n = 23), and thoracoabdominal aortic aneurysms (n = 44). Images from computed tomography and magnetic resonance imaging were evaluated after three-dimensional reconstruction to examine the growth rate in those with >1 year of imaging follow-up (n = 108). Survival data were derived from all 200 patients in this study.

RESULTS

Average proximal aortic dimensions at the index image were relatively small, measuring 3.65 ± 0.51 cm in the root, 3.67 ± 0.48 cm in the ascending aorta, and 3.50 ± 0.44 cm in the proximal arch. Average growth rate was low for the aortic root, ascending aorta, and proximal arch at 0.36 ± 0.64 mm/y, 0.26 ± 0.44 mm/y, and 0.25 ± 0.44 mm/y, respectively. There was no difference in baseline proximal aortic dimensions and growth rate between the four subgroups. An index aortic diameter ≥4.1 cm grew faster than those <4.1 cm at the ascending aorta (P = .028) and proximal arch (P = .019). There was no difference in aortic growth rates at the aortic root (P = .887). After the index scan, five patients underwent six ascending aortic replacement procedures, leading to a 3% ascending aortic intervention rate. Overall median life expectancy was 86.15 years.

CONCLUSIONS

Native ascending aortic growth in patients with descending thoracic aortic disease is slow. We suggest regular follow-up for index ascending aorta ≥4.1 cm because of its larger initial size and more rapid growth.

Hybrid Endovascular Aortic Arch Reconstruction for Acute Aortic Dissection: An Endovascular Bridge Technique for Complex Anatomy

Acute type A aortic dissections starting at the arch pose a challenge for cardiac surgeons. Open surgical repair requires deep hypothermic circulatory arrest for arch reconstruction and is associated with significant morbidity and mortality. Hybrid aortic repair techniques, with open arch debranching and thoracic endovascular aortic repair, have been employed in high-risk cases and challenging aortic pathology. Herein, we present a case of a 33-year-old African American male with a history of open thoracoabdominal aortic reconstruction and femoral-femoral artery bypass for a type B dissection who subsequently presented with new-onset chest pain and was found to have a retrograde type A dissection of a bovine arch with multiple dissection flaps and possible contrast extravasation on chest computed tomography. Endovascular reconstruction of the aortic arch using a hybrid technique was utilized and proved to be feasible and further should be considered when complex anatomy limits traditional surgical options.

Update on the Therapeutic Strategy of Type B Aortic Dissection

Stanford type B aortic dissection (TBAD) is a life-threatening disease. Current therapeutic guidelines recommend medical therapy with aggressive blood pressure lowering for patients with acute TBAD unless they have fatal complications. Although patients with uncomplicated TBAD have relatively low early mortality, aorta-related adverse events during the chronic phase worsen the long-term clinical outcome. Recent advances in thoracic endovascular aortic repair (TEVAR) can improve clinical outcomes in patients with both complicated and uncomplicated TBAD. According to present guidelines, complicated TBAD patients are recommended for TEVAR. However, the indication in uncomplicated TBAD remains controversial. Recent results of randomized trials, which compared the clinical outcome in patients treated with optimal medical therapy and those treated with TEVAR, suggest that preemptive TEVAR should be considered in uncomplicated TBAD with suitable aortic anatomy. However, these trials failed to show improvement in early mortality in patients treated with TEVAR compared with patients treated with optimal medical therapy, which suggest the importance of patient selection for TEVAR. Several clinical and imaging-related risk factors have been shown to be associated with early disease progression. Preemptive TEVAR might be beneficial and should be considered for high-risk patients with uncomplicated TBAD. However, an interdisciplinary consensus has not been established for the definition of patients at high-risk of TBAD, and it should be confirmed by experts including physicians, radiologists, interventionalists, and vascular surgeons. This review summarizes the current understanding of the therapeutic strategy in patients with TBAD based on evidence and expert consensus.

Retrograde Ascending Dissection After Thoracic Endovascular Aortic Repair Combined With the Chimney Technique and Successful Open Repair Using the Frozen Elephant Trunk Technique

The chimney technique can be combined with thoracic endovascular aortic repair (TEVAR) to both obtain an appropriate landing zone and maintain blood flow of the arch vessels. However, surgical repair becomes more complicated if retrograde type A aortic dissection occurs after TEVAR with the chimney technique. We herein report a case involving a 73-year-old woman who developed a retrograde ascending dissection 3 months after TEVAR for acute type B aortic dissection. To ensure an adequate proximal sealing distance, the proximal edge of the stent graft was located at the zone 2 level and an additional bare stent was placed at the left subclavian artery (the chimney technique) at the time of TEVAR. Enhanced computed tomography revealed an aortic dissection involving the ascending aorta and aortic arch. Surgical aortic repair using the frozen elephant trunk technique was urgently performed. The patient survived without stroke, paraplegia, renal failure, or other major complications. Retrograde ascending dissection can occur after TEVAR combined with the chimney technique. The frozen elephant trunk technique is useful for surgical repair in such complicated cases.

Comparison of thoracic endovascular aortic repair, open surgery and best medical treatment for type B aortic dissection: A meta-analysis

BACKGROUND

Treatments of type B aortic dissection (TBAD) include thoracic endovascular aortic repair (TEVAR), best medical treatment (BMT) and open surgery (OS). This meta-analysis was to compare these three strategies to evaluate which provides best outcomes.

METHODS

We searched clinical trials that compared treatment strategies for TBAD. The outcomes measures were 30-day/in-hospital mortality, long-term survival rate, paraplegia or paraparesis, renal failure, rupture, stroke, late re-intervention, late rupture and aneurismal dilatation/expansion.

RESULTS

Sixteen control trials covering 10,307 patients were evaluated. Meta-analysis showed that TEVAR provides preferable long-term survival rate (HR=0.71; 95% CI: 0.52-0.95), lower rate of late re-intervention (OR=0.33; 95% CI: 0.13-0.85), late rupture (OR=0.21; 95% CI: 0.10-0.43) and late aneurismal dilatation/expansion (OR=0.15; 95% CI: 0.04-0.63) compared with BMT. However, TEVAR seemed to be associated with higher stroke rate than BMT (OR=1.65; 95% CI: 1.21-2.23). 30-day/in-hospital mortality appeared to be lower in TEVAR (OR=0.49; 95% CI: 0.29-0.81) when compared with OS. In addition, OS induced higher 30-day/in-hospital mortality compared with BMT (OR=3.95, 95% CI: 1.56-10.02).

CONCLUSIONS

Our study shows that TEVAR may be favorable in long-term outcomes and effectively provide morphologic advantages compared to BMT. However, there is a need for prophylactic measures against stroke in TEVAR. OS seems to be inferior to TEVAR both in short-term and long-term outcomes. Further studies especially randomized clinical trials are needed to comprehensively compare the efficacy between TEVAR and BMT.