Acute Type B Aortic Dissection Patients Research Articles

Readmission after thoracic endovascular aortic repair following blunt thoracic aortic injury.

Thoracic endovascular aortic repair (TEVAR) is increasingly utilized to treat blunt thoracic aortic injury (BTAI), but post-discharge outcomes remain underexplored. We examined 90-day readmission in patients treated with TEVAR following BTAI. Adult patients discharged alive after TEVAR for BTAI in the Nationwide Readmissions Database between 2016 and 2019 were included. Outcomes examined were 90-day non-elective readmission, primary readmission reasons, and 90-day mortality. As a complementary analysis, 90-day outcomes following TEVAR for BTAI were compared with those following TEVAR for acute type B aortic dissection (TBAD). We identified 2085 patients who underwent TEVAR for BTAI. The median age was 43years (IQR, 29-58), 65% of all patients had an ISS ≥ 25, and 13% were readmitted within 90days. The main primary causes for readmission were sepsis (8.8%), wound complications (6.7%), and neurological complications (6.5%). Two patients developed graft thrombosis as primary readmission reasons. Compared with acute TBAD patients, BTAI patients had a significantly lower rate of readmission within 90days (BTAI vs. TBAD; 13% vs. 29%; p < .001). We found a significant proportion of readmission in patients treated with TEVAR for BTAI. However, the 90-day readmission rate after TEVAR for BTAI was significantly lower compared with acute TBAD, and the common cause for readmission was not related to residual aortic disease or vascular devices. This represents an important distinction from other patient populations treated with TEVAR for acute vascular conditions. Elucidating differences between trauma-related TEVAR readmissions and non-traumatic indications better informs both the clinician and patients of expected post-discharge course. Level of evidence/study type: IV, Therapeutic/care management.

Age-related difference in acute type B aortic dissection.

The objective is to compare the characteristics of clinical data, imaging data, and treatment methods of young and old patients with acute type B aortic dissection (ABAD). ABAD patients admitted to the Department of Vascular Surgery of the First Affiliated Hospital of Anhui Medical University from January 2012 to December 2018 were retrospectively reviewed. Patient demographics, such as gender, age, diabetes, hypertension, presenting symptoms, imaging characteristics, laboratory data on admission, hemodynamics on admission and in-hospital management, and mortality of different age groups were compared and analyzed. Categorical variables were compared using χ2 tests or Fisher's exact test. Continuous variables were compared using Student's t-test or Mann-Whitney U-test. A total of 141 ABAD patients were included in this study. Old ABAD patients were more likely to have a prior history of hypertension (88.6% vs 70.4%, p = 0.037) and atherosclerosis (29.8% vs 7.4%, p = 0.016). In the young group, Marfan syndrome was significantly higher (14.8% vs 0.9%; p = 0.005). Compared with the old group, the number of distal tears in the young group was significantly higher (62.3% vs 39.5%, p = 0.027). The proportion of patients with malperfusion of lower limbs in the young group was significantly higher than that in the old group (22.2% vs 6.1%, p = 0.026). There was no significant difference in the treatment methods and in-hospital mortality between the two groups. Compared with old ABAD patients, young ABAD patients had more distal tears and a higher proportion of lower limbs malperfusion.

A systematic review and meta-analysis of retrograde type A aortic dissection after thoracic endovascular aortic repair in patients with type B aortic dissection.

Retrograde type A dissection (RTAD) is a devastating complication of thoracic endovascular repair (TEVAR) with low incidence but high mortality. The objective of this study is to report the incidence, mortality, potential risk factors, clinical manifestation and diagnostic modalities, and medical and surgical treatments. A systematic review and single-arm and two-arm meta-analyses evaluated all published reports of RTAD post-TEVAR through January 2021. All study types were included, except study protocols and animal studies, without time restrictions. Outcomes of interest were procedural data (implanted stent-grafts type, and proximal stent-graft oversizing), the incidence of RTAD, associated mortality rate, clinical manifestations, diagnostic workouts and therapeutic management. RTAD occurred in 285 out of 10,600 patients: an estimated RTAD incidence of 2.3% (95% CI: 1.9-2.8); incidence of early RTAD was approximately 1.8 times higher than late. Wilcoxon signed-rank testing showed that the proportion of RTAD patients with acute type B aortic dissection (TBAD) was significantly higher than those with chronic TBAD (P = .008). Pooled meta-analysis showed that the incidence of RTAD with proximal bare stent TEVAR was 2.1-fold higher than with non-bare stents: risk ratio was 1.55 (95% CI: 0.87-2.75; P = .13). Single arm meta-analysis estimated a mortality rate of 42.2% (95% CI: 32.5-51.8), with an I2 heterogeneity of 70.11% (P < .001). RTAD is rare after TEVAR but with high mortality, especially in the first month post-TEVAR with acute TBAD patients at greater risk as well as those treated with proximal bare stent endografts.

Long-term results of type B aortic dissection patients with tumor after endovascular repair or optimal medical therapy: a single\u2014center and retrospective cohort study

BackgroundThe effect of thoracic endovascular aortic repair (TEVAR) for acute Type B aortic has been confirmed, However, when patients with malignant disease suffer from acute type B aortic dissection (ATBAD), the effect of TEVAR intervention is still unclear.MethodsATBAD patients were identified from electronic medical records between 2009 and 2019. The 5 year overall and aortic-disease free survival rates were analyzed and compared between the two groups.ResultsOf the 40 enrolled patients, 27 (67.5%) received TEVAR and 13 (32.5%) received OMT. The baseline characteristics of the two groups were not significantly different. Kaplan‒Meier survival curve showed that the 5 year overall survival and 5 year aortic-disease free survival of the TEVAR group were better than those of the OMT group. The Cox proportional hazard model with unadjusted risk showed an 83.0% decrease in 5 year overall mortality (HR, 0.17; 95% CI, 0.05–0.56) and a lower aortic-disease related risk (HR, 0.08; 95% CI, 0.02–0.39) in TEVAR group compared to OMT group. After adjusted for age, gender, smoking, drinking and comorbidities (diabetes mellitus, hypertension and coronary artery diseases), the hazard ratio of 5 year overall mortality was 78.0% lower (HR, 0.22; 95% CI, 0.06.0.81) and the risk of aortic-disease related mortality was 93.0% lower (HR, 0.07; 95% CI, 0.01–0.61) in TEVAR group compared to OMT group. In the cohort stratified by age, sex, the risk of the 5 year overall or aortic-disease related mortality in TEVAR group was relatively reduced compared to OMT group.ConclusionsCompared to OMT, TEVAR improves the 5 year overall and aortic-disease free survival rates in the cohort of ATBAD patients with a single type of malignant tumors.

Analysis of aortic wall stress and morphology in patients with type B aortic dissection

Risk assessment is critical in preventing aortic dissection (AD). This study aims to evaluate the wall stress (WS) distribution, especially at the locations of proximal tears in patient-specific type-B aortic dissection (TBAD) to explore the pathogenesis of dissection. In addition, the shape of the aortas were assessed and associated with TBAD risk. In this paper, 30 three-dimensional models were reconstructed based on patient-specific CT angiography images, and finite element analysis (FEA) was used to analyze the admission blood pressure. In addition, the anatomic variables including the head vessel angles, the aorta diameters, curvatures and torturosity ware measured. Tears occurred at either local high WS or low WS region, and these acute TBAD patients can be classified into three groups based on the location of initial intimal tears. In addition, the WS values at tear sites of each group showed significant difference (P＜0.001). Moreover, the angles of the left subclavian and brachiocephalic arteries were statistical different among three groups. Increased wall stress or decreased wall strength both contribute to the pathogenesis of aortic dissections. In addition, abnormal head vessel angles may be monitored as an important risk factor for aortic dissection, and its specific features may further help to determine the potential tear location.

Prognostic dynamic nomogram integrated with metabolic acidosis for in-hospital mortality and organ malperfusion in acute type B aortic dissection patients undergoing thoracic endovascular aortic repair

BackgroundOrgan malperfusion is a lethal complication in acute type B aortic dissection (ATBAD). The aim of present study is to develop a nomogram integrated with metabolic acidosis to predict in-hospital mortality and organ malperfusion in patients with ATBAD undergoing thoracic endovascular aortic repair (TEVAR).MethodsThe nomogram was derived from a retrospectively study of 286 ATBAD patients who underwent TEVAR from 2010 to 2017 at a single medical center. Model performance was evaluated from discrimination and calibration capacities, as well as clinical effectiveness. The results were validated using a prospective study on 77 patients from 2018 to 2019 at the same center.ResultsIn the multivariate analysis of the derivation cohort, the independent predictors of in-hospital mortality and organ malperfusion identified were base excess, maximum aortic diameter ≥ 5.5 cm, renal dysfunction, D-dimer level ≥ 5.44 μg/mL and albumin amount ≤ 30 g/L. The penalized model was internally validated by bootstrapping and showed excellent discriminatory (bias-corrected c-statistic, 0.85) and calibration capacities (Hosmer–Lemeshow P value, 0.471; Brier Score, 0.072; Calibration intercept, − 0.02; Slope, 0.98). After being applied to the external validation cohort, the model yielded a c-statistic of 0.86 and Brier Score of 0.097. The model had high negative predictive values (0.93–0.94) and moderate positive predictive values (0.60–0.71) for in-hospital mortality and organ malperfusion in both cohorts.ConclusionsA predictive nomogram combined with base excess has been established that can be used to identify high risk ATBAD patients of developing in-hospital mortality or organ malperfusion when undergoing TEVAR.

Prognostic Value of Preoperative Hemoglobin Levels for Long-Term Outcomes of Acute Type B Aortic Dissection Post-thoracic Endovascular Aortic Repair.

Background and Aims: There is scant information available about the prognostic value of preoperative hemoglobin (Hb) levels on the long-term outcomes of acute type B aortic dissection (ABAD) following thoracic endovascular aortic repair (TEVAR).Methods: A retrospective analysis of consecutive patients from 2010 to 2018 regarding the relationship between Hb level and long-term outcomes was conducted. The primary endpoint was all-cause mortality. Major adverse cardiovascular events (MACEs) included all-cause death, recurrent ruptures, and secondary procedures.Results: In total, 391 subjects treated by TEVAR were enrolled, with a mean age of 57.1 ± 12.0 years; 79.5% of them were male. Cox multivariate analysis showed that the preoperative Hb level was independently associated with all-cause death [adjusted hazard ratio (HR) 0.797 (per 1 g/dl), 95% confidence interval (CI) 0.693–0.918, p = 0.002] and MACEs (adjusted HR 0.795, 95% CI 0.672–0.871, p = 0.000). The area under the receiver operating characteristic curve of Hb for all-cause death and MACEs were 0.617 (95% CI 0.548–0.687, p = 0.008) and 0.617 (95% CI 0.551–0.684, p = 0.005), respectively. In the linear trend test, Hb concentration was significantly related to all-cause mortality (p for trend = 0.001) and MACEs (p for trend = 0.000). Moreover, in Kaplan–Meier analysis, lower Hb levels (< 12 g/dl) were significantly different from higher Hb (≥12 g/dl) levels for both all-cause death (log-rank p = 0.001) and MACEs (log-rank p = 0.001). Similar results were found when assessing the prognostic value of red blood cell count and anemia.Conclusions: Preoperative Hb may serve as a prognostic marker for long-range adverse outcomes for ABAD patients post-TEVAR.

Outcomes from the Gore Global Registry for Endovascular Aortic Treatment in patients undergoing thoracic endovascular aortic repair for type B dissection

ObjectiveThe Global Registry for Endovascular Aortic Treatment (GREAT) is a prospective multicenter registry collecting real-world data on the performance of W. L. Gore (Flagstaff, Ariz) aortic endografts. The purpose of the present study was to analyze the implementation and outcomes of thoracic endovascular aortic repair (TEVAR) in GREAT patients with type B aortic dissection (TBAD). MethodsFrom 2010 to 2016, >5000 patients were enrolled in the GREAT from 113 centers in 14 countries across 4 continents. The study population comprised those treated for TBAD. The primary outcomes of interest were mortality and freedom from aortic events (AEs). ResultsA total of 264 patients (80% male; mean age, 62 years) underwent TEVAR for the treatment of 170 (64%) acute and 94 (36%) chronic cases of TBAD. Chronic TBAD patients required significantly longer endograft coverage than did acute TBAD patients (P = .05). Early postoperative complications occurred in 9% of patients, with no difference in chronic vs acute dissection (P = .11). The 30-day aortic mortality and all-cause mortality were 1.5% and 2.3%, respectively, with no differences based on chronicity. During a mean follow-up of 26 months, the total aortic mortality was 2.7% and the total all-cause mortality was 12.5%. The all-cause mortality was significantly greater for chronic vs acute TBAD (19.2% vs 8.8%, respectively; P = .02). On multivariate analysis, patients with acute uncomplicated dissections had significantly improved overall survival compared with all other categories of dissections (93% vs 83% at 2 years; P < .05). A proximal landing zone diameter >40 mm was associated with an increased risk of retrograde type A dissection (18% vs 2%; P = .02). Patients undergoing left subclavian artery (LSA) coverage experienced a twofold greater rate of AEs compared with noncoverage patients (P < .01). Patients who underwent LSA revascularization experienced a 1.5-fold greater rate of AEs compared with patients covered without revascularization (P = .04). ConclusionsTEVAR for TBAD using the conformable GORE TAG thoracic endoprosthesis device can be performed with a low incidence of aortic mortality and complications. Acute uncomplicated TBAD patients had a significantly lower mortality rate than that of other patients. Larger proximal landing zones were associated with more frequent retrograde type A dissection. LSA involvement (coverage and/or revascularization) was associated with an increased risk of AEs during follow-up.

Risk of Mortality After Resolution of Spinal Malperfusion in Acute Dissection

Spinal cord ischemia (SCI) may develop in patients presenting with acute aortic dissection. We sought to determine how SCI and its recovery affect outcomes. We reviewed patients with SCI in acute type A aortic dissection (ATAAD) and acute type B aortic dissection (ATBAD) from September 1999 to May 2014. SCI was defined as paraplegia or paraparesis present on admission. Monoparesis/plegia, paraesthesia, or numbness was defined as ischemic neuropathy. All ATBAD patients were managed with antiimpulse therapy, with selective intervention for rupture, rapid aortic expansion, malperfusion, or intractable pain. ATAAD patients were managed with urgent proximal aortic replacement. Neurologic symptoms were present in 178 (18.2%) of 978 acute dissections (482 ATAAD and 496 ATBAD). Of these 178 patients, SCI presented in 52 patients (29.2%; 80.1% male; mean age, 57 years). On admission paraplegia was present in 24 (46.2%), paraparesis in 10 (19.2%), paresthesia/numbness in 27 (51.9%), and leg ischemia in 25 (48.1%). Aortic operations were performed in 27 SCI patients (51.9%). Symptom resolution was seen in 30 (57.7%). The 30-day mortality was 19.2% and was significantly less in those with resolution of SCI (6.7% vs 36.4%, p= 0.012). When surgical intervention was required in ATBAD with SCI, mortality was 50% (p= 0.039). SCI and symptom resolution significantly affected overall survival. SCI is associated with significantly increased risk of overall mortality (hazard ratio, 2.9; p < 0.001), and SCI resolution completely offsets this risk (hazard ratio, 0.28; p= 0.003). These effects were consistent between ATAAD and ATBAD (p= 0.554). SCI in acute aortic dissection portends a poor prognosis. However, reversal of deficits is associated with a long-term survival outcome comparable to patients unaffected with SCI.

Impact of initial aortic diameter and false-lumen area ratio on Type B aortic dissection prognosis.

Medical treatment is the gold standard for uncomplicated acute Type B aortic dissection (ATBAD). Although endovascular treatment could become an alternative therapy, it is unclear which ATBAD patients should undergo endovascular intervention. We aimed to evaluate the outcomes of patients with uncomplicated ATBAD and identify the risk factors for major adverse events. We retrospectively reviewed 134 consecutive patients who underwent initial treatment for uncomplicated ATBAD between 2004 and 2015. Follow-up rate was 98.5%, and the median follow-up period was 47 months. We evaluated the incidence of major adverse events (aortic-related death, aortic surgery and dilated aorta ≥ 55 mm) and identified the predictors of major adverse events using multivariable analysis. In-hospital mortality rate was 0.7% (1/134). During follow-up, 46 patients had major adverse events. The 1-, 3-, and 5-year rates of freedom from major adverse events were 79.8%, 71.4%, and 63.6%, respectively. The independent risk factors for major adverse events were initial aortic diameter ≥40 mm (hazard ratio 3.735, 95% confidence interval 1.888-7.390; P < 0.001) and false-lumen diameter > true-lumen diameter (hazard ratio 3.411, 95% confidence interval 1.491-7.806; P = 0.004). Initial aortic diameter ≥40 mm and false-lumen diameter > true-lumen diameter are predictors of major adverse events after uncomplicated ATBAD. Patients with these risk factors may benefit from early endovascular intervention. UMIN 000025388, https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000029229.

Acute type B aortic dissection complicated by visceral ischemia

Acute type B aortic dissection (ABAD) can lead to visceral malperfusion, a potentially life-threatening complication. The purpose of this study was to investigate the presentation, management, and outcomes of ABAD patients with visceral ischemia who are enrolled in the International Registry of Acute Aortic Dissection. Patients with ABAD enrolled in the registry between 1996 and 2013 were identified and stratified based on presence of visceral ischemia at admission. Demographics, medical history, imaging results, management, and outcomes were compared for patients with versus without visceral ischemia. A total of 1456 ABAD patients were identified, of which 104 (7.1%) presented with visceral ischemia. Preoperative limb ischemia (28% vs 7%, P<.001) and acute renal failure (41% vs 14%, P<.001) were more common among patients with visceral ischemia. Endovascular treatment and surgery were offered to 49% and 30% of the visceral ischemia cohort, respectively; remaining patients were managed conservatively. The in-hospital mortality was 30.8% for patients with visceral ischemia and 9.1% for those without visceral ischemia (odds ratio [OR] 4.44; 95% confidence interval [CI], 2.8-7.0, P<.0001). Mortality rates were similar after surgical and endovascular management of visceral ischemia (25.8% and 25.5%, respectively, P=not significant). Among the visceral ischemia group, medical management was a predictor of mortality in multivariate analysis (OR, 5.91; 95% CI, 1.2-31.0; P=.036). Patients with ABAD complicated by visceral ischemia have a high risk of mortality. We observed similar outcomes for patients treated by endovascular management versus surgery, whereas medical management was an independent predictor of mortality. Early diagnosis and intervention for visceral ischemia seems to be crucial.

Predicting aortic enlargement in type B aortic dissection.

Patients with uncomplicated acute type B aortic dissection (ABAD) can generally be treated with conservative medical management. However, these patients may develop aortic enlargement during follow-up, with the risk of rupture. Several predictors have been studied in recent years to identify ABAD patients at high risk of aortic enlargement, who may benefit from early surgical or endovascular intervention. This study reviewed and summarized the current available literature on prognostic variables related to aortic enlargement during follow-up in uncomplicated ABAD patients. It revealed multiple factors affecting aortic expansion including demographic, clinical, pharmacologic and radiologic variables. Such predictors may be used to identify those ABAD patients at higher risk for aortic enlargement who may benefit from closer radiologic surveillance or early endovascular intervention. This approach deserves even more consideration because a significant number of patients develop aneurysmal degeneration along the dissected segments during follow-up, and may lose the opportunity for endovascular treatment if not identified at an early stage.

Partial thrombosis of the false lumen influences aortic growth in type B dissection.

In the acute setting, the majority of patients affected by uncomplicated acute type B aortic dissection (ABAD) can be managed with medical therapy. In these patients, inhospital outcome is generally acceptable, with mortality rates of 1-10% (1,2). However, long-term outcomes in this group is less positive, with a mortality rates reported as 2025% within 3 years. Predictors of long-term complications have been a highly debated topic in recent years. Reports from the International Registry of Acute Aortic Dissection (IRAD) have shown that a partially thrombosed false lumen is associated with increased surgical mortality. Among ABAD patients discharged alive, those presenting with a partially thrombosed false lumen had an increased rate of mortality, after adjusting for age, gender and type of in-hospital treatment (3). One hypothesis for this observation is that partial thrombosis of the false lumen may occlude distal re-entry tears (“sac formation”), resulting in higher diastolic pressure (4). The purpose of this study was to determine whether partial thrombosis of the false lumen in ABAD patients is associated with increased aortic expansion (5).

Abstract 18293: Predicting In-Hospital Mortality in Acute Type B Aortic Dissection: Evidences From IRAD

Introduction: The outcome of acute type B aortic dissection (ABAD) patients is strongly related to the clinical presentation. The purpose of this study was to investigate predictors for mortality among patients presenting ABAD and to create a predictive model to estimate individual risk of in-hospital mortality using the International Registry of Acute Aortic dissection (IRAD). Methods: All ABAD patients enrolled in IRAD between 1996 and 2013 were included for analysis. Multivariate logistic regression analysis was used to investigate predictors of in-hospital mortality. Significant risk factors for in-hospital death were used to develop a prediction model. Results: A total of 1034 ABAD patients were included for analysis (673 male; mean age 63.5 ± 14.0), with an overall in-hospital mortality of 10.4%. In multivariate analysis, the following variables at admission were independently associated with increased in-hospital mortality: increasing age (OR 1.03, 95%CI 1.00-1.06, p=.044), hypotension/shock (OR 6.43, 95%CI 2.88-18.98), periaortic hematoma (OR 3.06, 95%CI 1.38-6.78, p=.006), descending diameter &gt;5.5cm, (OR 6.04, 95%CI 2.87-12.73, p&lt;.001), mesenteric ischemia (OR 9.03, 95%CI 3.49-23.38, p&lt;.001), acute renal failure (OR 3.61, 95%CI 1.68-7.75) and limb ischemia (OR 3.02, 95%CI 1.05-8.68, p=.040). Based on these multivariate results, a reliable and simple bedside risk prediction tool was developed. Conclusion: The clinical presentation of ABAD is heterogeneous and strongly predicts in-hospital outcome. We present a simple prediction model using variables that are independently associated with in-hospital mortality in ABAD patients. This model could be used to assist physicians in their choice of management and for informing patients and their families.

Morphologic predictors of aortic dilatation in type B aortic dissection

Conservative management of acute type B aortic dissection (ABAD) is often associated with aortic dilatation during follow-up increasing the risk of aortic rupture. The goal of this study was to investigate whether morphologic characteristics of the dissection can predict aortic growth. All conservatively managed ABAD patients from four referral centers were included (2000 to 2010). Aortic diameters were measured at five levels at baseline and at the last follow-up computed tomography angiography, and annual aortic growth rates were calculated for all segments. Linear regression was used to study the influence of aortic morphologic characteristics for aortic dilatation. Included were 62 patients (41 men) with a mean age of 60.3 ± 10.7 years. Among the 310 analyzed aortic segments, 248 (80.0%) were dissected, of which 211 (85.1%) showed aortic growth. Overall, the mean diameter increased from 36.1 ± 9.4 to 40.2 ± 11.1 mm (P < .01), which corresponds with a mean aortic growth rate of 3.1 ± 6.3 mm/y. Multivariate linear regression analysis showed that male sex (95% confidence interval [CI], 0.60-4.04; P = .005) and a saccular false lumen (95% CI, 2.07-7.81: P = .001) were associated with a significantly increased aortic growth rate. Increasing age (95% CI, -0.23 to -0.04; P = .005), increased number of entry tears (95% CI, -2.40 to -0.43; P = .005), false lumen located on the aortic outer curvature (95% CI, -4.30 to -0.38; P = .019), and a circular configuration of the true lumen (95% CI, -5.35 to -0.32; P = .027) were associated with a decreased aortic growth rate. Multiple morphologic characteristics appear to predict aortic dilatation in ABAD patients treated medically. Early assessment of these morphologic signs may be useful in the selection of ABAD patients who might benefit from closer radiologic surveillance or prophylactic intervention.

Number of Entry Tears Is Associated With Aortic Growth in Type B Dissections

Aortic growth rate in acute type B aortic dissection (ABAD) is a significant predictor for aortic complications and death. To improve the overall outcome, radiologic predictors might stratify patients who benefit from successful medical management vs those who require intervention. This study investigated whether the number of identifiable entry tears in ABAD patients is associated with aortic growth. ABAD patients with uncomplicated clinical conditions and therefore treated with medical therapy were evaluated. Those with a computed tomography angiography (CTA) obtained at clinical presentation and a subsequent CTA obtained at least 90 days after medical treatment were included (2005 to 2010). The CTAs were investigated for the number of entry tears between the true and false lumen. Diameters of the dissected aortas were measured at five levels on the baseline and on the last available follow-up CTA, and annual aortic growth rates were calculated. The number of entry tears in these patients and the location in the aorta were compared with the aortic growth rate. Included were 60 patients who presented with 243 dissected segments. Mean growth rates during follow-up (median, 23.2; range, 3 to 132 months) were significantly higher in patients with 1 entry tear (5.6 ± 8.9 mm) than in those with 2 (2.1 ± 1.7 mm; p = 0.001) and 3 entry tears (mean 2.2 ± 4.1; p = 0.010). The distance of the primary entry tear from the left subclavian artery did not have an effect on the aortic growth rate (median, 38; interquartile range, 24 to 137 mm; p = 0.434). The number of entry tears in ABAD patients detected on the first CTA after clinical presentation is a significant predictor for aortic growth. Patients with 1 entry tear at presentation show a higher growth rate than other patients and might benefit from more strict surveillance or early prophylactic intervention.

Abstract 18456: Morphologic Predictors of Aortic Growth in Conservatively Treated Type B Aortic Dissection

Purpose: Conservative management of acute type B aortic dissection (ABAD) is often associated with aortic enlargement during follow-up, increasing the risk of aortic rupture. The goal of this study was to investigate whether morphologic characteristics of the dissection can predict annual aortic growth. Methods: All conservatively managed type B dissection patients of four referral centers were included (2000-2010). Aortic diameters were measured at 5 levels on the baseline and last follow-up CTA, and annual aortic growth rates were calculated for all segments. Linear regression was used to study the influence of aortic morphologic characteristics on aortic enlargement. Results : Sixty-two patients were included (41 male; mean age 60.3 ± 10.7 years). Among the 310 analyzed segments, 248 (80.0%) were dissected of which 211 (85.1%) showed aortic growth. Overall, the mean diameter increased from 36.1 ± 9.4 mm to 40.2± 11.1mm (p &lt; 0.001) corresponding with a mean aortic growth of 3.1 ± 6.3 mm/year. Multivariate linear regression analysis showed male gender (95% CI 0.84 - 4.27; p = .004), detection of entry tears (95% CI 0.32 - 8.01; p = .034,) and a saccular false lumen (95% CI 1.50 - 7.28: p = .003) were associated with a significantly increased aortic growth rate. Increasing age (95% CI -0.24 - -0.5; p = .003), false lumen located on the convexity (95% CI -4.56- -0.64; p = .009) and a circular configuration of the true lumen (95% CI -5.04 - -0.02; p = .048) were associated with a decreased aortic growth rate. Conclusions: Age, gender, saccular false lumen, detection of entry tears, the presence of the entry tear in the oncavity of and configuration of the true lumen, appear to affect aortic growth rates in conservatively treated ABAD patients. Assessment of these characteristics may be useful in the selection of ABAD patients who might benefit from closer radiologic surveillance or early intervention.

Invited Commentary

Despite recent advances made in the knowledge of the natural history and prognosis of acute type B aortic dissection (ABAD), many questions still linger. In this way, the International Registry of Acute Aortic Dissection (IRAD) comprises a unique source of vital information that definitely is helping understand the long-term outcomes of such patients. In this cohort analysis [1Jonker F.H.W. Trimarchi S. Rampoldi V. et al.Aortic expansion after acute type B aortic dissection.Ann Thorac Surg. 2012; 94: 1223-1229Abstract Full Text Full Text PDF PubMed Scopus (76) Google Scholar], the findings are relevant and with likely straight clinical implications. The unexpected observation that patients with smaller aortas (aortic diameter <4 cm) exhibited increased aortic expansion over time compared to those with larger aortas (diameter ≥4 cm) still warrants a reasonable explanation, but going forward we must remember that those patients should be watched closely and more cautiously than previously thought. The use of calcium channel blockers was consistently able to retard the aorta diameter enlargement in the long-run; therefore, it has been a promising novel and important tool in our armamentarium for treating these patients. This information is in consonance with and strengthens previous publication [2Suzuki T. Isselbacher E.M. Nienaber C.A. et al.Type-selective benefits of medications in treatment of acute aortic dissection (from the International Registry of Acute Aortic Dissection [IRAD]).Am J Cardiol. 2012; 109: 122-127Abstract Full Text Full Text PDF PubMed Scopus (141) Google Scholar] in which calcium channel blockers was independently associated with improved survival during follow-up among the IRAD cohort of ABAD patients. Furthermore, some findings challenge data from prior reports. The prognostic implications of false lumen partial thrombosis have been an object of controversy and a previous study from IRAD found this entity a significant predictor of postdischarge mortality, compared with false lumen patency [3Tsai T.T. Evangelista A. Nienaber C.A. et al.Partial thrombosis of the false lumen in patients with acute type B aortic dissection.N Engl J Med. 2007; 357: 349-359Crossref PubMed Scopus (525) Google Scholar]. However, this finding has been contradicted by the data presented herein, not confirming the higher mortality related to the increased aortic expansion among these patients. The possible increased follow-up mortality for those patients with partial false lumen thrombosis remains open and unexplained; therefore, further research is needed about its effect on the prognosis of ABAD. Aortic Expansion After Acute Type B Aortic DissectionThe Annals of Thoracic SurgeryVol. 94Issue 4PreviewA considerable number of patients with acute type B aortic dissection (ABAD) treated with medical management alone will exhibit aortic enlargement during follow-up, which could lead to aortic aneurysm and rupture. The purpose of this study was to investigate predictors of aortic expansion among ABAD patients enrolled in the International Registry of Acute Aortic Dissection. Full-Text PDF

Aortic Expansion After Acute Type B Aortic Dissection

A considerable number of patients with acute type B aortic dissection (ABAD) treated with medical management alone will exhibit aortic enlargement during follow-up, which could lead to aortic aneurysm and rupture. The purpose of this study was to investigate predictors of aortic expansion among ABAD patients enrolled in the International Registry of Acute Aortic Dissection. We analyzed 191 ABAD patients treated with medical therapy alone enrolled in the registry between 1996 and 2010, with available descending aortic diameter measurements at admission and during follow-up. The annual aortic expansion rate was calculated for all patients, and multivariate regression analysis was used to investigate factors affecting the expansion rate. Aortic expansion was observed in 59% of ABAD patients; mean expansion rate was 1.7±7 mm/y. In multivariate analysis, white race (regression coefficient [RC], 4.6; 95% confidence interval [CI], 1.4 to 7.7) and an initial aortic diameter less than 4.0 cm (RC, 6.3; 95% CI, 4.0 to 8.6) were associated with increased aortic expansion. Female sex (RC, -3.8; 95% CI, -6.1 to -1.4), intramural hematoma (RC, -3.8; 95% CI, -6.5 to -1.1), and use of calcium-channel blockers (RC, -3.8; 95% CI, -6.2 to -1.3) were associated with decreased aortic expansion. White race and a small initial aortic diameter were associated with increased aortic expansion during follow-up, and decreased aortic expansion was observed among women, patients with intramural hematoma, and those on calcium-channel blockers. These data raise the possibility that the use of calcium-channel blockers after ABAD may reduce the rate of aortic expansion, and therefore further investigation is warranted.

Acute type B aortic dissection in the absence of aortic dilatation

Increasing aortic diameter is thought to be an important risk factor for acute type B aortic dissection (ABAD). However, some patients develop ABAD in the absence of aortic dilatation. In this report, we sought to characterize ABAD patients who presented with a descending thoracic aortic diameter <3.5 cm. We categorized 613 ABAD patients enrolled in the International Registry of Acute Aortic Dissection from 1996 to 2009 according to the aortic diameter <3.5 cm (group 1) and ≥3.5 cm (group 2). Demographics, clinical presentation, management, and outcomes of the two groups were compared. Overall, 21.2% (n = 130) had an aortic diameter <3.5 cm. Patients in group 1 were younger (60.5 vs 64.0 years; P = .015) and more frequently female (50.8% vs 28.6%; P < .001). They presented more often with diabetes (10.9% vs 5.9%; P = .050), history of catheterization (17.0% vs 6.7%; P = .001), and coronary artery bypass grafting (9.7% vs 3.4%; P = .004). Marfan syndrome was equally distributed in the two groups. The overall in-hospital mortality did not differ between groups 1 and 2 (7.6% vs 10.1%; P = .39). About one-fifth of patients with ABAD do not present with any aortic dilatation. These patients are more frequently females and younger, when compared with patients with aortic dilatation. This report is an initial investigation to clinically characterize this cohort, and further research is needed to identify risk factors for aortic dissection in the absence of aortic dilatation.