Long-term prognosis of patients with type B aortic intramural hematoma

Features and outcomes of focal intimal disruption in acute type B intramural haematoma

OBJECTIVES

A focal intimal disruption (FID) is a risk factor for adverse aorta-related events in patients with acute type B intramural haematoma. This study evaluated the impact of FIDs on overall survival with a selective intervention strategy for large or growing FIDs. Additionally, this study evaluated the risk factors associated with the growth of FIDs.

METHODS

This retrospective study included all consecutive patients admitted for acute type B intramural haematomas between November 2004 and April 2021. The primary outcome was overall survival. The secondary outcome was the cumulative incidence of composite aortic events and the growth of FIDs. The latter was calculated on centreline-reconstructed computed tomography images.

RESULTS

A total of 105 patients were included. A total of 106 FIDs were identified in 73 patients (73/105, 69.5%). The 1- and 5-year cumulative incidence rates of composite aortic events were 36.2% and 39.2%, respectively. The 1- and 5-year overall survival was 93.3% and 81.5%, respectively. Initial maximal aortic diameter and large FIDs during acute phase were significant risk factors for composite aortic events, but not risk factors for overall survival. The early appearance interval of an FID was a significant risk factor for growth of an FID.

CONCLUSIONS

With a selective intervention strategy for large or growing FIDs, the presence of large FIDs during the acute phase does not affect overall survival. The early appearance interval was associated with the growth of FIDs.

Acute Type B Intramural Hematoma: Novel Insights in the Endovascular Era

BACKGROUND

The pathophysiology and behavior of acute type B intramural hematoma (TBIMH) is poorly understood. The purpose of this study is to characterize the pathophysiology, fate, and outcomes of TBIMH in the endovascular era.

METHODS

A retrospective analysis of a US Aortic Database identified 70 patients with TBIMH from 2008 to 2022. Patients were divided into groups and analyzed based upon subsequent management: early thoracic endovascular aortic repair (TEVAR; Group 1) or hospital discharge on optimal medical therapy (OMT) (Group 2).

RESULTS

Of 70 total patients, 43% (30/70) underwent TEVAR (Group 1) and 57% (40/70) were discharged on OMT (Group 2). There were no significant differences in age, demographics, or comorbidities between groups. Indications for TEVAR in Group 1 were as follows: 1) Penetrating atheroscletoic ulcer (PAU) or ulcer-like projection (n = 26); 2) Descending thoracic aortic aneurysm (n = 3); or 3) Progression to type B aortic dissection (TBAD) (n = 2). Operative mortality was zero. No patient suffered a stroke or spinal cord ischemia. During the follow-up period, 50% (20/40) of Group 2 patients required delayed surgical intervention, including TEVAR in 14 patients and open repair in 6 patients. Indications for surgical intervention were as follows: 1) Development of a PAU / ulcer-like projection (n = 13); 2) Progression to TBAD (n = 3), or 3) Concomitant aneurysmal disease (n = 4). Twenty patients did not require surgical intervention. Of the initial cohort, 71% of patients required surgery, 9% progressed to TBAD, and 19% had regression or stability of TBIMH with OMT alone.

CONCLUSIONS

The most common etiology of TBIMH is an intimal defect. Progression to TBAD and intramural hematoma regression without an intimal defect occurs in a small percentage of patients. An aggressive strategy with endovascular therapy and close surveillance for TBIMH results in excellent short-term and long-term outcomes.

Sex Differences in DeBakey Type I/II Acute Aortic Dissection Outcomes: The Tokyo Acute Aortic Super-network

Background

Sex differences in the clinical presentation and outcomes of DeBakey type I/II (Stanford type A) acute aortic dissection (AAD) remain unclear.

Objectives

The authors aimed to determine the impact of sex on the clinical presentation and in-hospital outcomes of surgically or medically treated patients with type I/II AAD.

Methods

We studied 3,089 patients with type I/II AAD enrolled in multicenter Japanese registry between 2013 and 2018. The patients were divided into 2 treatment groups: surgical and medical. Multivariable logistic regression was used to examine the association between sex and in-hospital mortality.

Results

In the entire cohort, women were older and more likely to have hyperlipidemia, previous stroke, altered consciousness, and shock/hypotension at presentation than men. Women had higher proportions of intramural hematomas and type II dissections than men. In the surgical group (n = 2,543), men had higher rates of preoperative end-organ malperfusion (P = 0.003) and in-hospital mortality (P = 0.002) than women. Multivariable analysis revealed that male sex was associated with higher in-hospital mortality after surgery (OR: 1.71; 95% CI: 1.24-2.35; P < 0.001). In the medical group (n = 546), women were older and had higher rates of cardiac tamponade (P = 0.004) and in-hospital mortality (P = 0.039) than men; no significant association between sex and in-hospital mortality was found after multivariable adjustment (OR: 0.95; 95% CI: 0.56-1.59; P = 0.832).

Conclusions

Male sex was associated with higher in-hospital mortality for type I/II AAD in the surgical group but not in the medical group. Further research is needed to understand the mechanisms responsible for worse surgical outcomes in men.

Comparison of population characteristics and clinical outcomes of patients with type B aortic dissection or aortic intramural hematoma underwent thoracic endovascular aortic repair: a propensity score-matched analysis

BACKGROUNDS

Survival and aortic-related adverse events after thoracic endovascular aortic repair (TEVAR) for aortic intramural hematoma (IMH) and aortic dissection (AD) are controversial. We aimed to assess the preoperative characteristics and to evaluate TEVAR outcomes of acute type B IMH and AD.

METHODS

Between June 2002 and May 2021, 83 patients with acute type B IMH and 755 patients with acute type B AD underwent TEVAR at the General Hospital of Northern Theater Command. We retrospectively analyzed data from these patients, including clinical characteristics and follow-up outcomes.

RESULTS

The patients with IMH were significantly older than the ones with AD (P < 0.001). Diabetes mellitus (P = 0.035) and ischemic cerebrovascular disease (P = 0.017) were more common in the IMH group than in the AD group. The results demonstrated a less long-term aortic-related death-free survival rate in the IMH group than the AD group for all the patients (P = 0.014) and the matched patients (P = 0.027). It also presents a lower long-term overall survival rate (P = 0.047) and aortic-related event-free rate (P = 0.048) in the IMH group than in the matched patients.

CONCLUSIONS

Compared with AD patients, patients with IMH who underwent TEVAR had a worse long-term outcome of aortic-related survival in all and matched patients.

Sex‐Related Differences in Clinical Features and In‐Hospital Outcomes of Type B Acute Aortic Dissection: A Registry Study

Background

The association between female sex and poor outcomes following surgery for type A acute aortic dissection has been reported; however, sex‐related differences in clinical features and in‐hospital outcomes of type B acute aortic dissection, including classic aortic dissection and intramural hematoma, remain to be elucidated.

Methods and Results

We studied 2372 patients with type B acute aortic dissection who were enrolled in the Tokyo Acute Aortic Super‐Network Registry. There were fewer and older women than men (median age [interquartile range]: 76 years [66–84 years], n=695 versus 68 years [57–77 years], n=1677; P<0.001). Women presented to the aortic centers later than men. Women had a higher proportion of intramural hematoma (63.7% versus 53.7%, P<0.001), were medically managed more frequently (90.9% versus 86.3%, P=0.002), and had less end‐organ malperfusion (2.4% versus 5.7%, P<0.001) and higher in‐hospital mortality (5.3% versus 2.7%, P=0.002) than men. In multivariable analysis, age (per year, odds ratio [OR], 1.06 [95% CI, 1.03–1.08]; P<0.001), hyperlipidemia (OR, 2.09 [95% CI, 1.13–3.88]; P=0.019), painlessness (OR, 2.59 [95% CI, 1.14–5.89]; P=0.023), shock/hypotension (OR, 2.93 [95% CI, 1.21–7.11]; P=0.017), non–intramural hematoma (OR, 2.31 [95% CI, 1.32–4.05]; P=0.004), aortic rupture (OR, 26.6 [95% CI, 14.1–50.0]; P<0.001), and end‐organ malperfusion (OR, 4.61 [95% CI, 2.11–10.1]; P<0.001) were associated with higher in‐hospital mortality, but was not female sex (OR, 1.67 [95% CI, 0.96–2.91]; P=0.072).

Conclusions

Women affected with type B acute aortic dissection were older and had more intramural hematoma, a lower incidence of end‐organ malperfusion, and higher in‐hospital mortality than men. However, female sex was not associated with in‐hospital mortality after multivariable adjustment.

Obstructive Sleep Apnoea in Stanford Type B Aortic Dissection Is Associated With Multiple Imaging Signs Related to Late Aortic Events

Background: Obstructive sleep apnoea (OSA) is highly prevalent in patients with Stanford type B aortic dissection (TBAD). Few studies have evaluated the effects of OSA on vascular changes in TBAD patients. This study aimed to explore the effect of OSA on aortic morphological changes in TBAD patients and its relation to late aortic events (LAEs).

Methods: This case-control study included 143 TBAD patients. The diameters of different parts of the aorta were measured based on computed tomography angiography (CTA). According to the apnoea-hypopnoea index (AHI), OSA was classified as mild (5 ≤ AHI ≤ 15), moderate (15 < AHI ≤ 30), or severe (AHI > 30). The false lumen (FL) status was evaluated and classified as partially thrombosed, patent, or completely thrombosed.

Results: The OSA prevalence in TBAD patients was 64.3%, and image differences related to LAEs between TBAD patients with and without OSA included the maximum aortic diameter at onset (37.3 ± 3.9 vs. 40.3 ± 4.5 mm, p < 0.001), the FL diameter of the proximal descending thoracic aorta (16.0 ± 6.8 vs. 20.3 ± 4.7 mm, p < 0.001), and the proportion of the FL that was partially thrombosed (39.2 vs. 64.1%, p = 0.004). Additionally, in the multivariable analysis of patients with OSA, the risks of an aortic diameter ≥40 mm, a proximal descending aorta FL ≥ 22 mm and a partially thrombosed FL were 4.611 (95% CI: 1.796–11.838, p = 0.001), 2.544 (95% CI: 1.050–6.165, p = 0.039), and 2.565 (95% CI: 1.167–5.637, p = 0.019), respectively, after adjustment for confounding factors. Trend tests showed that the risks of an aortic diameter ≥40 mm and a partially thrombosed FL increased with increasing OSA severity.

Conclusions: TBAD patients with moderate to severe OSA have aortic dilatation in different parts of the aorta. OSA is an independent risk factor for multiple imaging signs related to LAEs, suggesting that OSA is an important factor affecting the prognosis of TBAD patients.

Predictors of Long-Term Aortic Growth and Disease Progression in Patients with Aortic Dissection, Intramural Hematoma, and Penetrating Aortic Ulcer

BACKGROUND

We aimed to identify predictors of long-term aortic diameter change and disease progression in a population cohort of patients with newly diagnosed aortic dissection (AD), intramural hematoma (IMH), or penetrating aortic ulcer (PAU).

METHODS

We used the Rochester Epidemiology Project record linkage system to identify all Olmsted County, MN-USA, residents diagnosed with AD, IMH, and PAU (1995-2015). The endpoints were aortic diameter change, freedom from clinical disease progression (any related intervention, aortic aneurysm, new aortic syndrome, rupture or death) and disease resolution (complete spontaneous radiological disappear). Linear regression was used to assess aortic growth rate; predictors of disease progression were identified with Cox proportional hazards.

RESULTS

Of 133 incident cases, 46 ADs, 12 IMHs, and 28 PAUs with sufficient imaging data were included. Overall median follow-up was 8.1 years. Aortic diameter increase occurred in 40 ADs (87%, median 1.0 mm/year), 5 IMHs (42%, median 0.2 mm/year) and 14 PAUs (50%, median 0.4 mm/year). Symptomatic presentation (P = 0.045), connective tissue disorders (P = 0.005), and initial aortic diameter >42 mm (P = 0.013) were associated with AD growth rate. PAU depth >9 mm (P = 0.047) and female sex (P = 0.013) were associated with aortic growth rate in PAUs and IMHs. At 10 years, freedom from disease progression was 22% (95% CI 12-41) for ADs, 44% (95% CI 22-92) for IMHs, and 46% (95% CI 27-78) for PAUs. DeBakey I/IIIB AD (HR 3.09; P = 0.038), initial IMH aortic diameter (HR 1.4; P = 0.037) and PAU depth >10 mm (HR 3.92; P = 0.018) were associated with disease progression. No AD spontaneously resolved; resolution rate at 10 years was 22% (95% CI 0-45) for IMHs and 11% (95% CI 0-23) for PAUs.

CONCLUSIONS

Aortic growth and clinical disease progression are observed in most patients with aortic syndromes, while spontaneous resolution is uncommon. Predictors of aortic growth and disease progression may be used to tailor appropriate follow-up and eventual early intervention.

A Three-Dimensional Deep Convolutional Neural Network for Automatic Segmentation and Diameter Measurement of Type B Aortic Dissection

OBJECTIVE

To provide an automatic method for segmentation and diameter measurement of type B aortic dissection (TBAD).

MATERIALS AND METHODS

Aortic computed tomography angiographic images from 139 patients with TBAD were consecutively collected. We implemented a deep learning method based on a three-dimensional (3D) deep convolutional neural (CNN) network, which realizes automatic segmentation and measurement of the entire aorta (EA), true lumen (TL), and false lumen (FL). The accuracy, stability, and measurement time were compared between deep learning and manual methods. The intra- and inter-observer reproducibility of the manual method was also evaluated.

RESULTS

The mean dice coefficient scores were 0.958, 0.961, and 0.932 for EA, TL, and FL, respectively. There was a linear relationship between the reference standard and measurement by the manual and deep learning method (r = 0.964 and 0.991, respectively). The average measurement error of the deep learning method was less than that of the manual method (EA, 1.64% vs. 4.13%; TL, 2.46% vs. 11.67%; FL, 2.50% vs. 8.02%). Bland-Altman plots revealed that the deviations of the diameters between the deep learning method and the reference standard were -0.042 mm (-3.412 to 3.330 mm), -0.376 mm (-3.328 to 2.577 mm), and 0.026 mm (-3.040 to 3.092 mm) for EA, TL, and FL, respectively. For the manual method, the corresponding deviations were -0.166 mm (-1.419 to 1.086 mm), -0.050 mm (-0.970 to 1.070 mm), and -0.085 mm (-1.010 to 0.084 mm). Intra- and inter-observer differences were found in measurements with the manual method, but not with the deep learning method. The measurement time with the deep learning method was markedly shorter than with the manual method (21.7 ± 1.1 vs. 82.5 ± 16.1 minutes, p < 0.001).

CONCLUSION

The performance of efficient segmentation and diameter measurement of TBADs based on the 3D deep CNN was both accurate and stable. This method is promising for evaluating aortic morphology automatically and alleviating the workload of radiologists in the near future.

Non-traumatic thoracic aortic emergencies: imaging diagnosis and management

The major component of non-traumatic thoracic aortic emergencies is the acute aortic syndromes. These include acute aortic dissection, intramural haematoma and penetrating atherosclerotic ulcer, grouped together because they are indistinguishable clinically and highly fatal. All three entities involve disruption to the tunica intima and media and may be complicated by rupture, end-organ ischaemia or aneurysmal transformation. Early diagnosis is vital to allow timely and appropriate management. Paired unenhanced and electrocardiogram-gated computed tomography angiography of the chest, extending more distally if required, is recommended for diagnosis. Specific computed tomography features of all three entities are reviewed, with a focus on morphological features associated with complications. Those with type A pathology are usually managed with open surgery because this has a high risk of complication. Patients with uncomplicated type B pathology are usually managed with best medical therapy whereas those with complicated type B pathology are usually offered either surgery or thoracic endovascular aortic repair. The limited evidence regarding the use of thoracic endovascular aortic repair in patients with subacute uncomplicated type B pathology is briefly discussed.

Differential clinical features and long-term prognosis of acute aortic syndrome according to disease entity

AIMS

To evaluate the acute and long-term prognosis of acute aortic syndrome (AAS) according to the disease entity [intramural haematoma (IMH) vs. aortic dissection (AD)] and the anatomical location (type A vs. B).

METHODS AND RESULTS

A total of 1012 patients [672 with AD and 340 with IMH (33.6%)] were enrolled between 1993 and 2015. Compared with AD patients, IMH patients were older and had higher frequency of female sex and distal aorta involvement. The overall crude in-hospital mortality of AAS was 8.6%; type A AD [15.0%; adjusted hazard ratio (aHR) 30.4; 95% confidence interval (CI) 8.62-107.3; P < 0.001], type A IMH (8.0%; aHR 4.85; 95% CI 1.29-18.2; P = 0.019), type B AD (5.0%; aHR 3.51; 95% CI 1.00-12.4; P = 0.051), and type B IMH [1.5%; aHR 1.00 (reference)]. During a median follow-up duration of 8.5 years (interquartile range: 4.0-13.5 years), AD (aHR 2.78; 95% CI 1.87-4.14; P < 0.001) and type A (aHR 2.28; 95% CI 1.45-3.58; P < 0.001) was associated with a higher risk of aortic death. After 90 days, a risk of aortic death was no longer associated with anatomical location (aHR 0.74; 95% CI 0.40-1.36; P = 0.33), but remained associated with disease entity (aHR 1.83; 95% CI 1.10-3.04; P = 0.02).

CONCLUSION

The clinical features, response to treatment strategy, and outcomes of IMH patients were distinct from those of AD patients. Both early and late survival was better for IMH than for AD. In addition to the anatomical location of AAS, the disease entity is an independent factor associated with both acute and long-term mortality in patients with AAS. Further investigation is necessary to confirm the prognostic implication of disease entity in different patient populations.

Prediction of adverse events in patients with initially medically treated type A intramural hematoma

BACKGROUND

Prior studies provided limited data regarding natural history of initially medically treated type A intramural hematoma (IMH).

OBJECTIVES

To develop predictive models for adverse aorta-related events in patients with type A IMH.

METHODS

We performed a retrospective pooled analysis of individual patient data, including baseline clinical and CT characteristics. All patients enrolled were followed up for adverse aorta-related events, defined as a composite of aortic disease-related death and the presence of aortic complications that required aortic invasive treatment.

RESULTS

A total of 172 patients (52.9% men) were included, with a mean age of 61.1 ± 11.2 years. During a median follow-up time of 770.5 (45.3-1695.8) days, 60 patients (34.9%) experienced adverse aorta-related events. In Cox regression model for predicting adverse aorta-related events, hypertension (HR = 3.78, p = .067), MAD (HR = 1.05, p = .018), presence of ULP (HR = 2.43, p = .002) and pericardial effusion (HR = 1.65, p = .061) were independently associated with adverse aorta-related events. A majority of the adverse aorta-related events (n = 46, 76.7%) occurred within acute and subacute phase (90 days) of IMH. In predictive model for 90 days aortic events, MAD≥50.7 mm (OR = 2.79, p = .006) and presence of ULP (OR = 3.20, p = .002) were independent predictors. C statistic of the predictive model were 0.71 (p < .001).

CONCLUSIONS

Predictive models including baseline clinical and CT characteristics as predictors allow for accurate estimation of risk of adverse aorta-related events in patients with type A IMH. The proposed predictive models are helpful for risk estimates and decision making.

Intramural hematoma and penetrating ulcer in the descending aorta: differences and similarities

Acute aortic syndromes include a variety of overlapping clinical and anatomic diseases. Intramural hematoma (IMH), penetrating atherosclerotic ulcer (PAU), and aortic dissection can occur as isolated processes or can be found in association. All these entities are potentially life threatening, so prompt diagnosis and treatment is of paramount importance. IMH and PAU affect patients with atherosclerotic risk factors and are located in the descending aorta in 60-70% of cases. IMH diagnosis can be correctly made in most cases. Aortic ulcer is a morphologic entity which comprises several entities-the differential diagnosis includes PAU, focal intimal disruptions (FID) in the context of IMH evolution and ulcerated atherosclerotic plaque. The pathophysiologic mechanism, evolution and prognosis differ somewhat between these entities. However, most PAU are diagnosed incidentally outside the acute phase. Persistent pain despite medical treatment, hemodynamic instability, maximum aortic diameter (MAD) >55 mm, significant periaortic hemorrhage and FID in acute phase of IMH are predictors of acute-phase mortality. In these cases, TEVAR or open surgery should be considered. In non-complicated IMH or PAU, without significant aortic enlargement, strict control of cardiovascular risk factors and frequent follow-up imaging appears to be a safe management strategy.

Acute type B aortic intramural hematoma: the added prognostic value of a follow-up CT

OBJECTIVES

To investigate prognostic significance of follow-up CT findings for initially medically treated type B aortic intramural hematoma (IMH).

METHODS

We performed a retrospective pooled analysis of individual patient data, including baseline and follow-up CT characteristics. All enrolled patients were followed up for adverse aorta-related events, defined as a composite of aortic disease-related death and surgical or endovascular aortic repair.

RESULTS

A total of 238 patients (73.9% men) were included, with a mean age of 58.1 ± 9.8 years. During follow-up, 83 patients (34.9%) experienced adverse aorta-related events, most of the events (83.1%) occurred within 1 month after follow-up CT imaging (n = 69). In the Cox regression model for predicting adverse aorta-related events, baseline maximal aortic diameter (MAD) (HR = 1.05, p = 0.008), ulcer-like projection (ULP) (HR = 2.47, p < 0.001), changes of maximal hematoma thickness (MHT) (HR = 1.22, p < 0.001), newly developed ULP (HR = 4.44, p < 0.001), and newly developed pleural effusion (HR = 2.46, p = 0.002) were powerful independent predictors. In combined predictive model for 1-month aortic events, baseline MHT ≥ 11.8 mm (OR = 4.39, p = 0.001), ULP (OR = 3.98, p < 0.001), changes of MHT (OR = 1.46, p < 0.001), newly developed ULP (OR = 9.27, p = 0.002), and newly developed pleural effusion (OR = 3.45, p = 0.015) were independent predictors. Besides, in patients with pleural effusion at baseline, resorption of pleural effusion was associated with adverse aorta-related events (HR = 0.36, p = 0.027) and 1-month aortic events (OR = 0.23, p = 0.026).

CONCLUSIONS

Follow-up CT findings provide strong and incremental prognostic information for initially medically treated type B IMH, which are helpful for risk estimates and decisions-making.

KEY POINTS

• Follow-up CT provides strong and incremental prognostic information for initially medically treated type B aortic intramural hematoma. • Follow-up CT is highly recommended for type B intramural hematoma in patients who did not receive urgent invasive therapy. • Follow-up CT is helpful for risk estimates and decisions-making.

Predictive value of 18F-FDG PET/CT in patients with acute type B aortic intramural hematoma

BACKGROUND

The clinical course and predictors of adverse aortic events (AAE) in patients with acute Stanford type B intramural hematoma (IMH) remain controversial. This study aimed to investigate whether 18F-FDG PET/CT can predict risk in patients with acute type B IMH.

METHODS AND RESULTS

This study included 34 patients with acute type B IMH who underwent PET/CT within 14 days from the onset of symptoms. The maximal standardized uptake values (SUVmax) of 18F-FDG uptake was significantly different between patients with or without AAE (4.3 ± 0.6 vs 3.7 ± 1.0, P = 0.020), but not the target to blood ratio (TBR, SUVmax divided by SUV in the superior vena cava) (1.6 ± 0.2 vs 1.5 ± 0.5, P = 0.064). In patients with initial ulcer-like projection (ULP), a blood-filled pouch protruding into the IMH, which was seen in 25 patients(74%), both the SUVmax and TBR were significantly higher in patients who developed AAE, (4.3 ± 0.6 vs 3.3 ± 0.5, P = 0.001; 1.6 ± 0.2 vs 1.4 ± 0.2, P = 0.01); the TBR >1.5, which is determined from receiver-operating-characteristic curve, had a sensitivity of 73% and a specificity of 80% in predicting AAE.

CONCLUSION

Patients with ULP and high 18F-FDG uptake were more likely to develop AAE and may require closer surveillance with serial imaging.

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.

Efficacy and Optimal Timing of Endovascular Treatment for Type B Aortic Dissection

OBJECTIVES

To determine the efficacy and the optimal timing of thoracic endovascular aortic repair (TEVAR) for closing the primary entry in uncomplicated patients with chronic type B aortic dissection and a patent false lumen (FL).

METHODS

Thirteen patients underwent TEVAR for aortic dissection between 2008 and 2012. These patients had chronic dissection with a patent FL and expansion of the aorta. Early TEVAR was performed for five patients within 1-7 months from the index dissection (TEVAR-EC group) and delayed TEVAR was performed for eight patients within 1-16 years (TEVAR-DC group). Changes in the diameters and volumes of the true lumen (TL) and FL and the aortic remodeling were assessed by multidetector computed tomography for 3 years after TEVAR.

RESULTS

The reduction rate of FL in the thoracic aorta was notably higher in the TEVAR-EC group than in the TEVAR-DC group regardless of the presence or absence of distal retrograde flow. There was a significant TL expansion despite different timings of TEVAR.

CONCLUSIONS

Early TEVAR resulted in good prognosis and preferable aortic remodeling in uncomplicated patients with chronic type B aortic dissection and a patent FL, and we recommend early TEVAR within seven months after the index dissection.

Midterm results of type B intramural hematoma endovascular treatment

BACKGROUND

Recently, intramural hematoma (IMH) has been characterized as a rare variant of aortic dissection, falling within the acute aortic syndromes (AAS). Although aortic endovascular treatment seems to provide good results, no consensus has been established regarding the optimal management of IMH affecting the descending thoracic aorta (IMH B). The aim of this study was to assess long-term clinical and morphological results of IMH B treated with a stent graft.

METHODS

Between 2002 and 2013, 15 of the 423 (3.5%) consecutive patients with AAS were found to have IMH B. During follow-up, complications related to IMH B were observed in 10 patients, including 5 during the acute period (<14 days). Surgical indications were ulcerations, refractory pain, aneurysm evolution, aortic rupture, and pleural effusion. An endovascular approach was taken for all forms with suitable anatomy.

RESULTS

Technical success rate was 100%, with complete exclusion of lesions of the descending thoracic aorta in all cases treated with a stent graft. No neurological complications or deaths occurred within the first 30 postoperative days, nor at the end of the mean follow-up of 46 months (1-137 months). After the aortic stent graft, partial or complete regression of the hematoma was observed in all cases.

CONCLUSIONS

IMH B is most often a progressive disease requiring long-term monitoring. In case of complications, stent-graft treatment of the descending thoracic aorta can be performed successfully in most cases. This procedure appears to be a safe technique that provides very good long-term results, with favorable remodeling of the aorta.

Acute type B aortic dissection with communicating vs. non-communicating false lumen

BACKGROUND

In practice, patients with acute aortic dissection (AAD) are generally divided into 2 groups according to the status of the false lumen: non-communicating or communicating. The similarities and differences between the 2 groups, however, have not been fully determined in a large population. METHODS AND RESULTS: We studied 502 patients with Stanford type B AAD. Clinical background at symptom onset was compared, and similarities and differences characterized, for patients with non-communicating (NC group, n=288) vs. communicating (C group, n=214) false lumens. Time of day (00.00-06.00 hours, 06.00-12.00 hours, 12.00-18.00 hours, and 18.00-24.00 hours) and extent of physical activity (extreme exertion, slight exertion, at rest, and sleeping) at symptom onset were similar between groups. Patients in the NC group were older (mean age, 71±11 years vs. 64±14 years, P<0.01) and had lower prevalence of distally extended aortic dissection (26% vs. 8%, P<0.01) and deaths in hospital (2% vs. 7%, P=0.011) than those in the C group.

CONCLUSIONS

At symptom onset, clinical circumstances and physical activity were similar between the groups, and old age and a background of DeBakey IIIa aortic dissection may be associated with determination of false lumen status. The outcome in the NC group was better than in the C group.

Treatment patterns and their outcomes of acute aortic intramural hematoma in real world: multicenter registry for aortic intramural hematoma

Background

Intramural hematoma of the aorta (IMH), a variant of classic aortic dissection, shows very dynamic process in the early phase. The aim of this study is to evaluate clinical outcomes of patients with acute aortic IMH from real world registry data.

Methods

We analyzed 165 consecutive patients with acute IMH from five medical centers in Korea. All patients were divided into two groups; type A (n = 61, 37.0%) and type B (n = 104, 63.0%) according to the Stanford classification. Clinical outcomes and morphological evolution by CT were analyzed for 2 years.

Results

Most of the patients (77.0% of type A and 99.0% of type B, P < 0.001) were treated medically during their initial hospitalization. There were no significant differences in in-hospital mortality (4.9% vs. 2.9%, P = 0.671) and 2-year mortality (13.1% vs. 11.5%, P = 0.765) between two groups. During the 2-year follow up period, progression to aortic dissection (18.0% vs. 6.7%, P = 0.037) and surgical treatment (29.5% vs. 2.9%, P < 0.001) were higher in type A. For the type A patients, there were no significant difference in in-hospital mortality (7.1% of surgery vs. 4.3% of medical, P = 0.428) and 2-year mortality (7.1% of surgery vs. 14.9% of medical, P = 0.450) in terms of initial treatment strategy.

Conclusion

For real world practice in Korea, most of IMH patients were treated medically at presentation and showed favorable outcomes. Thus, even in type A acute IMH, early medical treatment with alternative surgical conversion for selected, complicated cases would be a favorable treatment option.

Renal dysfunction on admission as a predictor for in-hospital mortality of patients with stanford type B acute aortic dissection

Stanford type A and open false lumen are accepted predictors for in-hospital mortality in patients with acute aortic dissection (AAD). However, the association of renal dysfunction on admission with in-hospital mortality is not well known. The aim of this study was to investigate the prognostic value of renal dysfunction in patients with AAD. A total of 250 patients with type B AAD admitted to our institution between January 2003 and August 2011 were enrolled in this study. In multivariate logistic regression analysis, the significant predictors of in-hospital mortality were age (odds ratio [OR] 1.575, 95% confidence interval [CI] 1.078-2.864, p = 0.024), maximum aortic diameter measured by an initial computed tomography (CT) (OR 1.740, 95% CI 1.029-2.940, p = 0.039), decreased enhancement of kidney (OR 7.716, 95% CI 2.335-25.501, p = 0.001) and estimated glomerular filtration rate (eGFR) <60 ml/min/1.73m(2) on admission (OR 2.782, 95% CI 1.062-7.283, p = 0.037). In conclusions the results identified a renal dysfunction on admission as the independent predictor of in-hospital mortality in type B AAD. Further investigations are needed to evaluate therapies and strategies for decreasing the deterioration of renal function to improve in-hospital mortality in patients with AAD.

Detection of Intimal Defect by 64-Row Multidetector Computed Tomography in Patients With Acute Aortic Intramural Hematoma

Background—

Previous pathological and clinical studies demonstrated an intimal defect in patients with acute aortic intramural hematoma (IMH). The purpose of this study was to investigate the prevalence and clinical outcome of intimal defect detected by multidetector computed tomography (MDCT) in patients with IMH.

Methods and Results—

We retrospectively analyzed 38 consecutive patients with IMH in whom 64-row MDCT was performed during the acute phase (median, 5 days from the onset). Intimal defect was defined as continuity disruption of the inner layer of thrombosed false lumen, which could be detected by 1-mm axial and longitudinal interactive multiplanar reformation images. Clinical outcome of intimal defect was assessed in patients with type B IMH (n=32). A total of 48 lesions in 27 (71%) patients were recognized as intimal defects. The incidence of intimal defect was not affected by the timing of MDCT examination (1 to 3 days, 79%; 4 to 7 days, 58%; 8 to 14 days, 75%; P =0.56). In type B IMH, 16 (76%) of 21 patients with intimal defect showed progression (enlargement or progression to aortic aneurysm) in the chronic phase. In contrast, all 11 patients without intimal defect had complete resorption of hematoma. In lesion-based analysis, a depth of intimal defect of ≥5 mm predicted progression with sensitivity, specificity, and positive and negative predictive values of 84%, 95%, 94%, and 86%, respectively.

Conclusions—

A considerable portion of patients with IMH showed intimal defect detected by MDCT even in the very early stage, and defects frequently enlarged. Patients with intimal defect should be carefully followed up with serial imaging.

Impact of New Development of Ulcer-Like Projection on Clinical Outcomes in Patients With Type B Aortic Dissection With Closed and Thrombosed False Lumen

Background— The purpose of this study was to investigate the clinical importance of newly developed ulcer-like projection (ULP) in patients with type B aortic dissection with closed and thrombosed false lumen (AD with CTFL), which is better known as aortic intramural hematoma.

Methods and Results— A total of 170 patients with acute type B AD with CTFL were admitted to our institution from 1986 to 2008 and treated initially with medical therapy. There were 31 late deaths, including 9 cases of aortic rupture. The actuarial survival rates of all patients were 99%, 89%, 83% at 1, 5, and 10 years, respectively. A total of 62 (36%) patients showed new ULP development within 30 days from the onset. Patients who had ULP showed significantly poorer survival rates than patients who did not have ULP ( P =0.037). Development of ULP was also associated with a significant increase in adverse aorta-related events ( P <0.001). In addition, patients with ULP in the proximal descending thoracic aorta (PD) showed significantly higher aorta-related event rates than patients without ULP in the PD ( P <0.001). Initial aortic diameter (hazard ratio, 3.55; P <0.001) and development of ULP in PD (hazard ratio, 3.79; P =0.003) were the strongest predictors of adverse aorta-related events.

Conclusions— Initial aortic diameter and development of ULP in the PD are both strong predictors of adverse aorta-related events in patients with type B AD with CTFL. Patients with newly developed ULP should be more carefully followed up with close surveillance imaging than those without ULP.

Clinical Outcomes of Medical Treatment of Acute Type A Intramural Hematoma

A retrospective study was performed in 30 patients who were treated for type A intramural hematoma from 1999 to 2008, of whom 24 were initially treated without surgical intervention. These 24 patients were followed up for 3.3 ± 3.5 years (range, 0 days to 10.0 years). Four hospital deaths occurred (hospital mortality, 16.7%), there were 2 late deaths, and 2 other patients needed an operation during the follow-up period. The event-free survival rate (freedom from death or surgery) at 5 years was significantly lower in patients with maximal aortic diameter ≤48 mm than in those with diameters <48 mm (28.6% ± 17.1% vs. 88.2% ± 7.8%). Maximal aortic diameter ≤48 mm and computed tomography findings of a small intimal defect were significant predictors of rupture or progression of ascending aortic dissection. The outcome of medical treatment for type A intramural hematoma was acceptable during both the early and late periods, but patients with a relatively large aortic diameter or an intimal defect in the ascending aorta have a high probability of adverse outcome, and must be considered for surgery.

Outcomes of patients with acute type a aortic intramural hematoma

BACKGROUND

The proper treatment option for patients with type A intramural hematoma (IMH), a variant form of classic aortic dissection (AD), remains controversial. We assessed the outcome of our institutional policy of urgent surgery for unstable patients and initial medical treatment for stable patients with surgery in cases with complications.

METHODS AND RESULTS

Among 357 consecutive patients with type A acute aortic syndrome, 101 (28.3%) had IMH and 256 had AD. Urgent operations were performed in 224 patients with AD (87.5%) and 16 with unstable IMH (15.8%; P<0.001). The remaining 85 stable IMH patients received initial medical treatment, and adverse clinical events developed in 31 patients (36.5%) within 6 months, which included development of AD (n=25), delayed surgery (n=25), or death (n=6). Initial aorta diameter and hematoma thickness were independent predictors for development of these events, and the best cutoff values were 55 and 16 mm, respectively. The overall hospital mortality was lower in IMH patients than in AD patients (7.9% [8/101] versus 17.2% [44/256]; P=0.0296) and was comparable to that of surgically treated AD patients (7.9% versus 10.7% [24/224]; P=0.56). The 1-, 2-, and 3-year survival rates of IMH patients were 87.6+/-3.6%, 84.9+/-3.7%, and 83.1+/-4.1%, respectively. There was no statistical difference of overall survival rates between patients with IMH and surgically treated AD patients (P=0.787).

CONCLUSIONS

The clinical outcome of IMH patients receiving treatment by our policy was comparable to that of surgically treated AD patients. However, adverse clinical events were not uncommon with medical treatment alone, and initial aorta diameter and hematoma thickness may identify patients who might benefit from urgent surgery.

What to Do When Evidence is Lacking — Implications on Treatment of Aortic Ulcers, Pseudoaneurysms and Aorto-Enteric Fistulae

Present knowledge on natural history and how to treat penetrating aortic ulcers or different forms of pseudoaneurysms with or without infection is limited as there are only case reports and small series of unusual aortic pathology and its treatment available.

Material:

From our centre we collected 65 patients treated with open (n=15) or endovascular reconstruction (n=50) during a 20-year period in the abdominal aorta. These patients are presented including a review of contemporary treatment.

Results:

Endovascular reconstructions seem to reduce morbidity and mortality compared to otherwise extensive open surgery. Even for patients with infectious etiology (mycotic aneurysms, aorto-enteric fistula) endovascular treatment may be a first-hand option bridging to a more elective open repair. However, a large proportion of patients being unfit for further open surgery were solely treated endovascularly and had no major infectious complications in the follow-up. Registers of cases with unusual aortic pathology, not only of those treated but also of those managed conservatively, are needed to define who to treat and if endovascular or open repair should be recommended.

Conclusion:

Endovascular technique is a promising technique for treatment of aortic pseudoaneurysms of different etiologies. We firmly recommend, despite the lack of evidence, that the work up of patients with penetrating aortic ulcers, mycotic or other types of pseudoanerysms as well as aorto-enteric fistulae should enclose both endovascular and open (or combined) treatment modalities. However, our knowledge of the natural history is limited. Therefore, registers of cases with unusual aortic pathology, not only of those treated but also of those managed conservatively, are needed to define who to treat and if endovascular or open repair should be recommended.

Intramural Hematoma and Penetrating Atherosclerotic Ulcer of the Aorta

Intramural hematoma and penetrating aortic ulcer are uncommon but potentially lethal thoracic aortic pathologies. Despite incomplete understanding of their natural history, they have emerged as anatomically appealing targets of endovascular therapy. Appropriate application of these technologies, however, must be predicated on an understanding of the fate of these lesions left untreated, and predictors of their misbehavior. We briefly review the current understanding of these entities.

CT Analysis of the Growth Rate of Aortic Diameter Affected by Acute Type B Intramural Hematoma

OBJECTIVE

The purpose of this study was to evaluate the growth rate of aortic diameter affected by acute type B intramural hematoma and the factors that influence its enlargement.

MATERIALS AND METHODS

Fifty-four patients were entered into this study, and regular follow-up CT studies (mean +/- SD, 46.9 +/- 27.2 months; range, 5-136 months) were performed. The affected aortas and iliac arteries were divided into five segments. A total of 127 segments were evaluated (aortic arch, n = 47; descending thoracic aorta, n = 51; suprarenal abdominal aorta, n = 24; infrarenal abdominal aorta, n = 3; and iliac artery, n = 2). The growth rate of each segment was obtained on CT. The factors influencing increase in the diameter and growth rate--age, sex, diabetes mellitus, atherosclerotic disease, history of smoking 20 years, chronic renal failure, blood pressure, initial diameter of the lumen, the presence of blood flow in the false lumen--were evaluated by univariate analysis and a multivariate logistic regression model.

RESULTS

Twenty (37.0%) of 54 patients had one or more segments that increased in size during the follow-up period. Of a total of 127 segments, 35 (27.6%) increased in size, and for all, the mean growth rate was -0.5 +/- 2.9 mm/year. This negative growth rate represents shrinkage. The mean growth rates within the first year and after 1 year from onset were -2.2 +/- 5.7 and 0.4 +/- 3.2 mm/year, respectively, and a significant difference was observed between them (p < 0.0001). An initial diameter of 40 mm or greater and the presence of blood flow in the false lumen were significant risk factors for an increase in the diameter, as confirmed by univariate and multivariate analyses.

CONCLUSION

In patients with type B intramural hematoma, the affected aortas did not show a high incidence of enlargement during the follow-up period, but the affected aortas tended to increase in size after 1 year from onset. An initial diameter of 40 mm or greater and the presence of blood flow in the false lumen were important risk factors for enlargement during the follow-up period.

Midterm Results of Aortic Diameter Outcomes After Thoracic Stent-Graft Implantation for Aortic Dissection: A Multicenter Study

PURPOSE

To evaluate aortic diameter outcomes after stent-graft implantation for aortic dissection in the descending thoracic aorta.

METHODS

Fifty patients with type A dissection after ascending aortic surgery (n = 10), type B dissection (n = 34), or intramural hematoma (n = 6) underwent stent-graft repair in 3 centers. Thrombosis and aortic diameter were analyzed by computed tomographic angiography at different levels of the aorta before stent-graft implantation, at discharge, and at follow-up. Measurements were standardized.

RESULTS

In all, 67 stent-grafts were implanted for acute (n = 18) and chronic (n = 32) dissection. Stent-graft placement was successfully performed with high technical success (100%) despite 4 major complications (iliac thrombosis in 2 cases, aortic rupture, and a type A dissection) in 3 (6%) patients. Complete thrombosis of the thoracic false lumen was observed in 42% and 63% of cases at discharge and at follow-up (mean 15 months), respectively. At follow-up, the diameters of the entire aorta (mean 5 mm, p < 0.05) and the false lumen (mean 11 mm, p < 0.0001) decreased. Diameters of the abdominal aorta remained stable in association with persistent false lumen perfusion at this level. Aortic diameter results were better in the subgroup of patients with intramural hematoma compared to patients with Marfan syndrome. Three early deaths unrelated to the stent-graft procedure occurred; 2 patients with partial thrombosis of the false lumen died in follow-up secondary to aortic diameter growth.

CONCLUSION

Complete thrombosis of the false lumen by stent-graft coverage of the entry tear results in decreased diameter of the entire aorta. In patients with partial thrombosis of the false lumen, the aneurysm continues to enlarge.