The Evaluation Characteristics of Type B Aortic Intramural Hematoma and Ten Years Treatment Outcomes ()
1. Introduction
IMH-B is characterized by aortic wall hematoma without intimal tear or direct flow communication between true and false. The etiology of this disease is unclear. Some researchers reported the cause may be related to spontaneous vasa vasorum bleeding in the aortic wall media without intimal disruption [1] [2]. Some studies showed that FID, pre-existing atherosclerosis, and hypertension may be risk factors for IMH-B [3] [4]. Previous studies indicated that IMH-B may be a subset of aortic dissections with very limited flow in the false lumen [5] [6]. Moreover, the evolution of IMH-B toward progression or regression under different conditions is not clear [7] [8]; therefore, how and when to deal with IMH-B becomes a focus in the world. Our study followed up the characteristics and evolution of IMH-B patients, explored the evolution predictors and the invasive treatment time for uncomplicated IMH-B patients.
2. Methods
2.1. Patients Collection
From May 2010 to May 2020, 81 type B aortic intramural hematoma (IMH-B) patients were collected from Liuzhou municipal Liutie central hospital (19/81, 23.5%), people’s hospital of Sanya city (36/81, 44.4%) and the second affiliated hospital of Shantou university medical college (26/81, 32.1%). All patients were diagnosed as type B aortic Intramural hematoma (IMH-B) with computed tomography angiography (CTA), IMH-B is noted as a descending aortic dissection without intimal tear, but now the intimal defects are detected with high-resolution computed tomography, so IMH-B may be a subset of aortic dissections with very limited flow in the false lumen. This study was approved by the ethics committees of three hospitals. The authors had full access to and take responsibility for the integrity of the data. All authors have read and agree to the manuscript as written.
2.2. Clinical Data
All patients’ clinical data were collected retrospectively from the medical records. The information included age, sex, history, clinical presentation, physical examination, imaging findings, medical treatment and invasive treatment, and outcomes. All data were verified by reviewing medical records and follow up data.
2.3. Follow-up Protocol
CTA was performed in all cases. Initial CTA images were selected and measured at 3 levels to evaluate aortic diameter and hematoma thickness in the descending aorta. Among 3 slices, the largest one was defined as maximum descending aortic diameter (MDAD) and maximum descending aortic hematoma thickness (MDAHT). CTA were also follow-up to detect IMH with APU and FID evolution and outcomes.
2.4. Data Analysis
All patients’ data such as presentation, physical findings, evaluation, management, and outcomes were collected. Image evolution was carefully tracked in initial and following-up patients’ imaging findings and assessed the outcomes. The relationship between the data of CTA image evolution and clinical events was analysis for detecting predictors and confirming the invasive treatment time.
2.5. Statistical Analysis
All results were presented here with mean ± SEM. Comparison between two groups was evaluated by Student’s t-test. One-way ANOVA was used to evaluate the significance of the difference between multiple groups. Survival curves were generated by the Kaplan–Meier method and difference in survival between groups used the log-rank test. Cox regression analysis was done to identify factors associated with the key endpoints. P values < 0.05 were considered to be statistically significant. Data analysis was performed with SPSS software (SPSS, Chicago, Illinois, version 22.0) and the survival curve of Kaplan–Meier was done with Graphpad prism 8.
3. Results
3.1. Patients Characteristics
Among the 81 patients of IMH-B, 57 (70.4%) were men and 24 (29.6%) were women, The mean age of the cohort was 67.2 ± 11.3 years. 76.5% patients of this study had history of hypertension. 26 patients accepted invasive treatment (24 underwent TEVAR and 2 underwent Surgery), there was no patient died; 55 patients received medical treatment, 7 (12.7%) died in acute and sub-acute phase and 48 survived. The survival curve of Kaplan-Meier was shown in Figure 1. The patients followed-up range: 1.2 - 36 months, median: 22 months. Characteristics of all patients are shown in Table 1.
3.2. Morphology Evolution of IMH-B
All patients were diagnosed acute IMH-B and followed up with CTA. Typical imaging data obtained between the acute phase and follow up phase. The evolution characteristics of aortic IMH, IMH with ULP and IMH with PAU, were shown in Figures 2(A)-(H) respectively.
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Figure 1. The Kaplan-Meier survival curves for IMH-B patients (n = 81). Compared with IT group (n = 26), the mortality of IMH-B patients of MT group was significantly high (n = 55), (p < 0.001).
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Figure 2. Morphology evolution for IMH-B patients. A - C showed Morphology evolution of IMH-B at day 0, day 5 and day 10 respectively; D - F showed Morphology evolution of ULP at day 0, day 7 and day 14 respectively; G - H showed Morphology evolution of PAU at day 0 and day 7.
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Table 1. The baseline characteristics of IMH-B patients (n = 81).
3.3. Progression Data Analysis
All Patients’ variety of CTA image data and morphological evolution model of IMH-B were shown in Table 2. The data indicated that MDAD < 35 mm, 82.1% Patients regression, 17.9% Patients progression (p < 0.001), and MDAHT < 6 mm, 73.3% Patients regression. 26.7% Patients progression (p < 0.05). However, when MDAD > 45 mm, 16.7% Patients regression, 83.3% Patients regression (p < 0.001), and MDAHT > 10 mm, 0 Patients regression, 100% Patients regression (p < 0.001). We also found that IMH-B with FID, 31.8% Patients regression, 68.2% Patients progression (p < 0.05), and IMH-B with PAU, 18.1% Patients regression, 81.9% Patients progression (p < 0.001). The model demonstrated that MDAD > 45 mm, MDAHT > 10 mm, IMH-B with FID, and IMH-B with PAU may be the risk factors for IMH-B patients.
3.4. Predictors of Progression
Aorta related events were demonstrated in the predictive model (Table 3). In 81 patients, 26 patients were treated with invasive treatment overall events 1, 26 (3.8%), And 55 patients were treated with medical treatment overall events 33, 55 (60.0%) p < 0.001, we found that most events related to aortia were occurrence in early 30 days. Among 55 patients, 12 patients were progressed to AD. 10 patients were progressed to periaortic hemorrhage, 4 patients were progressed to pleural effusion, and 7 patients were dead. Compared with invasive treatment group, 1 patient was progressed to AD p < 0.001, 0 patients were progressed to periaortic hemorrhage p < 0.001, 0 patients were progressed to pleural effusion p < 0.001, and 0 patients were dead p < 0.001. Univariate analysis showed MDAD, MDAHT, IMH with AUP, IMH with FID as the significant predictors. Multivariate Cox regression analysis MDAD (hazard ratio, 3.58; 95% CI, 1.25 - 5.78; p < 0.001), MDAHT (hazard ratio, 4.26; 95% CI, 0.85 - 7.84; p < 0.001), and IMH with PAU (hazard ratio, 3.58; 95% CI, 1.02 - 5.63; p < 0.001) were confirmed as the independent predictors of early and late progression (Table 4).
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Table 2. The morphological evolution model (n = 81).
Two groups were evaluated by Student’s t-test and multiple groups by One-way ANOVA.
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Table 3. The predictive model (n = 81).
Two groups were evaluated by Student’s t-test and multiple groups by One-way ANOVA.
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Table 4. Predictors analysis for IMH-B patients (n = 81).
Cox-regression analysis.
4. Discussion
The findings of present study were as follows: MDAD > 45 mm, MDAHT > 10 mm, and IMH with PAU may be the important predictors for uncomplicated IMH-B patients. Most adverse aorta related events occurred within 30 days. It would be careful follow-up, closely observe for these patients within 30 days, and take necessary treatment strategies in time.
There has been a controversy regarding the treatment of IMH-B. The mainly treatment strategy for IMH-B was medical treatment, However, the evolution of IMH-B appears to be more progression related events than that of invasive treatment group [9] [10]. In present report, we constructed morphology evolution model to IMH-B patients and observed progression related events. Our data was shown total 81 patients, 26 patients were treated with invasive treatment overall events 1, 26 (3.8%), And 55 patients were treated with medical treatment overall events 33, 55 (60.0%) p < 0.001. Among 55 patients, 12 patients were progressed to AD. 10 patients were progressed to periaortic hemorrhage, 4 patients were progressed to pleural effusion, and 7 patients were dead. Compared with invasive treatment group, 1 patient was progressed to AD p < 0.001, 0 patients were progressed to periaortic hemorrhage p < 0.001, 0 patients were progressed to pleural effusion p < 0.001, and 0 patients were dead p < 0.001. If IMH-B become IMH-A or type A aortic dissection. Surgery would be performed in time. 26 patients received invasive treatment, 24 patients underwent TEVAR and 2 surgeries in our study. IMH-B is most often a progressive disease. In case of complications, invasive treatment would be a good method in most high risk cases.
However, how to confirm the invasive treatment indications and when to select treatment strategies are the major difficulties for IMH-B patients. It has been reported that adverse aortic-related events could help risk stratification and management decisions [11] [12] [13]. Some researchers indicated that most of the adverse aorta-related events happened within 1 month during follow-up [11] [14] [15]. In the present study, we constructed the predictive models for IMH-B patients, screened the morphology evolution of IMH-B patients. The data indicated that MDAD < 35 mm, 82.1% Patients regression, 17.9% Patients progression (p < 0.001), and MDAHT < 6 mm, 73.3% Patients regression. 26.7% Patients progression (p < 0.05). However, when MDAD > 45 mm, 16.7% Patients regression, 83.3% Patients regression (p < 0.001), and MDAHT > 10 mm, 0 Patients regression, 100% Patients regression (p < 0.001). We also found that IMH-B with FID, 31.8% Patients regression, 68.2% Patients progression (p < 0.05), and IMH-B with PAU, 18.1% Patients regression, 81.9% Patients progression (p < 0.001). In order to find out the relationship between the morphology evolution of IMH-B and aorta related events for the IMH-B patients, we explored predictors of progression in aorta related events model, In 81 patients, 26 patients were treated with invasive treatment overall events 1, 26 (3.8%), And 55 patients were treated with medical treatment overall events 33, 55 (60.0%) p < 0.001. Among 55 patients, 12 patients were progressed to AD. 10 patients were progressed to periaortic hemorrhage, 4 patients were progressed to pleural effusion, and 7 patients were dead. Compared with invasive treatment group, 1 patient was progressed to AD p < 0.001, 0 patients were progressed to periaortic hemorrhage p < 0.001, 0 patients were progressed to pleural effusion p < 0.001, and 0 patients were dead p < 0.001. Univariate analysis showed MDAD, MDAHT, IMH with AUP, IMH with FID as the significant predictors. Multivariate Cox regression analysis MDAD (hazard ratio, 3.58; 95% CI, 1.25 - 5.78; p < 0.001), MDAHT (hazard ratio, 4.26; 95% CI, 0.85 - 7.84; p < 0.001), and IMH with PAU (hazard ratio, 3.58; 95% CI, 1.02 - 5.63; p < 0.001) were confirmed as the independent predictors of early and late progression.
5. Limitations
We constructed initial two models for the present retrospective observational study. The mainly limitations are as follows: Firstly, the number of patients enrolled was small, which might have data selection and analysis bias. Secondly, most events related aorta occurred in acute and sub-acute phase (within 30 days). How to confirm the exact time for each IMH-B patient is required investigation. Finally, the two models need to be further improved and a large-scale randomized control trial is required.
6. Conclusions
1) MDAD > 45 mm, MDAHT > 10 mm, and IMH with PAU may be the independent risk predictors for uncomplicated IMH-B patients.
2) In acute IMH-B, most adverse aorta related events occurred within 30 days.
3) Invasive treatment may be the safe and effective way for high risk IMH-B patients.
Abbreviations
TEVAR: thoracic endovascular aortic repair
IT: invasive treatment
MT: medical treatment
IMH-B: Type B intramural hematoma
PAU: penetrating aortic ulcer
ULP: ulcer like projection
CTA: computed tomography angiography
AD: aortic dissection
MDAD: maximum descending aortic diameter
MDAHT: maximum descending aortic hematoma thickness