Effects of partial thrombosis on distal aorta after repair of acute DeBakey type I aortic dissection

False lumen hemodynamics and partial thrombosis in chronic aortic dissection of the descending aorta

OBJECTIVES

Partial thrombosis of the false lumen (FL) in patients with chronic aortic dissection (AD) of the descending aorta has been associated with poor outcomes. Meanwhile, the fluid dynamic and biomechanical characteristics associated with partial thrombosis remain to be elucidated. This retrospective, single-center study tested the association between FL fluid dynamics and biomechanics and the presence and extent of FL thrombus.

METHODS

Patients with chronic non-thrombosed or partially thrombosed FLs in the descending aorta after an aortic dissection underwent computed tomography angiography, cardiovascular magnetic resonance (CMR) angiography, and a 4D flow CMR study. A comprehensive quantitative analysis was performed to test the association between FL thrombus presence and extent (percentage of FL with thrombus) and FL anatomy (diameter, entry tear location and size), fluid dynamics (inflow, rotational flow, wall shear stress, kinetic energy, and flow acceleration and stasis), and biomechanics (pulse wave velocity).

RESULTS

Sixty-eight patients were included. In multivariate logistic regression FL kinetic energy (p = 0.038) discriminated the 33 patients with partial FL thrombosis from the 35 patients with no thrombosis. Similarly, in separated multivariate linear correlations kinetic energy (p = 0.006) and FL inflow (p = 0.002) were independently related to the extent of the thrombus. FL vortexes, flow acceleration and stasis, wall shear stress, and pulse wave velocity showed limited associations with thrombus presence and extent.

CONCLUSION

In patients with chronic descending aorta dissection, false lumen kinetic energy is related to the presence and extent of false lumen thrombus.

CLINICAL RELEVANCE STATEMENT

In patients with chronic aortic dissection of the descending aorta, false lumen hemodynamic parameters are closely linked with the presence and extent of false lumen thrombosis, and these non-invasive measures might be important in patient management.

KEY POINTS

• Partial false lumen thrombosis has been associated with aortic growth in patients with chronic descending aortic dissection; therefore, the identification of prothrombotic flow conditions is desirable. • The presence of partial false lumen thrombosis as well as its extent was related with false lumen kinetic energy. • The assessment of false lumen hemodynamics may be important in the management of patients with chronic aortic dissection of the descending aorta.

Distal Aortic Progression After Hemiarch, Zones 1-3 Arch Replacement in Acute Type A Aortic Dissection

BACKGROUND

There is debate regarding aortic arch repair extent for acute type A aortic dissection (ATAAD) patients.

METHODS

From 1996 to 2021, 756 ATAAD patients underwent open arch replacement. The cohort was divided into hemiarch (n = 481), zone 1 (n = 65), zone 2 (n = 148), and zone 3 (n = 62) arch replacement groups. Cross-group comparison of aortic growth was modeled using data from interval postoperative computed tomography or magnetic resonance imaging of the distal aorta.

RESULTS

Demographics were not significantly different except the hemiarch group had more coronary artery disease and less stroke. Intraoperatively, zones 1, 2, and 3 had greater cardiopulmonary bypass, cross-clamp, and hypothermic circulatory arrest times and required more intraoperative blood transfusion than the hemiarch group. Perioperative outcomes were similar among groups except zone 3 had more reoperation for bleeding. Ten-year cumulative incidence of reoperation was hemiarch, 16.7%; zone 1, 16.3%; zone 2, 21.5%; and zone 3, 17.6% (P = .70). Ten-year survival was similar: hemiarch, 66%; zone 1, 60.3%; zone 2, 68.0%); and zone 3 66.1% (P = .20). Aortic arch, descending aorta, and abdominal aorta growth rates were not significantly different among groups over 10 years. In the whole cohort, the growth rate over time for aortic arch was 0.38 mm per year (P < .001), descending aorta 0.84 mm per year (P < .001), and abdominal aorta 0.69 mm per year (P < .001).

CONCLUSIONS

There was no significant difference in long-term survival, distal aorta growth, or reoperation rate for distal aortic aneurysm after hemiarch or zones 1, 2, or 3 arch replacement. Patient-specific arch replacement strategies may be used rather than defaulting to aggressive arch replacement for all ATAAD patients.

Predictive factors of distal stent graft-induced new entry after frozen elephant trunk procedure for aortic dissection

OBJECTIVES

The incidence rate of distal stent graft-induced new entry after frozen elephant trunk technique for aortic dissection remains controversial. The aim of this study was to investigate the incidence and seek the clinical and anatomical predictive factors.

METHODS

This study is a retrospective multicenter evaluation of complications including distal stent graft-induced new entry, aortic events, and re-intervention after the frozen elephant trunk procedure for aortic dissection.

RESULTS

Our cohort included total 177 consecutive patients who underwent the frozen elephant trunk procedure for acute and chronic aortic dissection at five centers in Japan from May 2014 to March 2021. The incidence rate of distal stent graft-induced new entry was 14.1% (25/177 patients). The cumulative incidence of d-SINE was 7.1%, 12.4%, 21.4% after 12, 36, and 60 months, respectively. Distal stent graft-induced new entry was not associated with mid-term survival rate. After competing risk regression analysis, onset time > 48 hours (subdistribution hazard ratio, 3.80; 95% confidence interval, 1.13-12.79; P=0.031) was detected as an independent predictor.

CONCLUSIONS

Awareness that there is a relatively higher incidence of distal stent graft-induced new entry after frozen elephant trunk procedures is important. Non-hyperacute phase was detected as an independent risk factor. Preemptive endovascular repair may be appropriate to protect new entry in high-risk patients.

Numerical modeling of residual type B aortic dissection: longitudinal analysis of favorable and unfavorable evolution

Residual type B aortic dissection was numerically investigated to highlight the contribution of biomechanical parameters to the pathology's evolution. Patient-specific geometries from cases involving both favorable and unfavorable evolution were modeled to assess their hemodynamic features. This original approach was supported by a longitudinal study confirming the association between morphological changes, hemodynamic features, adverse clinical outcomes, and CT-angioscan observations on the same patient. Comparing one patient with unfavorable evolution with one with favorable one, we identify potential biomechanical indicators predictive of unfavorable evolution: (i) a patent false lumen with a flow rate above 50% of inlet flow rate; (ii) high wall shear stress above 18 Pa at entry tears, and above 10 Pa at some regions of the false lumen wall; (iii) low time-averaged wall shear stress in distal false lumen below 0.5 Pa; (iv) vortical structure dynamics. Although these comparisons could only be conducted on 2 patients and need to be confirmed by a larger number of cases, our findings point to these hemodynamic markers as possible candidates for early evaluation of the pathology's evolution towards an unfavorable scenario. Graphical Abstract Correlation between hemodynamics index and thrombus initiation for unfavorable case. ET₂ and ET₃ are entry tear numbers 2 and 3 respectively. WSS is wall shear stress. TAWSS is time average shear stress.

Postoperative Maximal Aortic Diameter is a Significant Predictor of Dilation of the Residual Dissected Aorta after Aortic Replacement for Acute Debakey Type I Aortic Dissection

BACKGROUND

This study investigated the impact of aortic diameter on late aortic dilation of the residual dissected aorta after tear-oriented aortic replacement for acute DeBakey type I aortic dissection.

METHODS

Of 133 patients who underwent aortic replacement for acute DeBakey type I/II aortic dissection between 2008 and 2019, 45 patients with a residual dissected aorta after surgery for acute DeBakey type I aortic dissection and who underwent computed tomography at predischarge and after 1 year were retrospectively assessed. The aortic diameter and false lumen area were measured at 3 levels: the maximal aortic site, seventh thoracic vertebra, and celiac axis. Multivariable Cox regression analysis was employed to identify the predictors of late aortic dilation, defined as an aortic growth rate of ≥5 mm/year or a maximal aortic diameter of ≥55 mm.

RESULTS

During a median follow-up of 75 [range: 13-152] months, 6 patients (5 men; mean age: 57 ± 14 years) experienced aortic dilation. All 6 patients had the maximal aortic diameter between the distal aortic arch and seventh thoracic vertebra level at the last computed tomography. Multivariable Cox regression analysis showed that the predischarge maximal aortic diameter was an independent determinant of late aortic dilation (hazard ratio: 2.28/mm, 95% confidence interval: 1.10-5.86).

CONCLUSIONS

Predischarge maximal aortic diameter is a significant predictor of late aortic dilation in patients with a residual dissected aorta after tear-oriented surgical repair of acute DeBakey type I aortic dissection.

Do oral anticoagulants impact outcomes and false lumen patency after repair of acute type A aortic dissection?

OBJECTIVE

The study objective was to analyze the effects of chronic oral anticoagulation on long-term outcomes after repair of type A acute aortic dissection and its influence on false lumen fate.

METHODS

We studied 188 patients (median age, 62 years; 74% were male) who underwent repair of type A aortic dissection; patients receiving postoperative chronic oral anticoagulation (n = 59) were compared with those receiving antiplatelet therapy alone (n = 129).

RESULTS

Median age was similar: 60 years (18-79 years; OAC group) versus 64 years (22-86; no-OAC group) (P = .11); patients taking anticoagulants were more frequently male (88% vs 67%, P = .003). After a median follow-up of 8.4 years (2 months to 30 years), 58 patients died, 18 of aortic-related causes, and 37 patients underwent aortic reintervention. After multivariable adjustment, anticoagulation showed no significant effect on long-term survival (hazard ratio, 0.85; 95% confidence interval, 0.41-1.76; P = .66) or risk of reintervention (hazard ratio, 0.55; 95% confidence interval, 0.27-1.15; P = .11). Analysis of 127 postoperative computed tomography scans showed a patent false lumen in 53% of anticoagulated patients versus 38% of nonanticoagulated patients (P = .09): partially thrombosed in 8% versus 28% (P = .01) and thrombosed in 39% versus 34% (P = .63), respectively. In patients with a control computed tomography, there were 6 late aortic-related deaths, 1 among anticoagulated patients and 5 in those who were not.

CONCLUSIONS

Chronic anticoagulation after repair of type A acute aortic dissection favors persistent late false lumen patency, which is not a risk factor for late mortality or reoperation. Chronic anticoagulation can be administered safely to patients with repaired type A acute aortic dissection regardless of its specific indication.

Distal Aortic Remodeling after Type A Dissection Repair: An Ongoing Mirage

Remodeling is a commonly encountered term in the field of cardiothoracic surgery that is often used to describe various pathophysiological changes in the dimension, structure, and function of various cardiac chambers, including the aorta. Stanford type A or DeBakey type 1 aortic dissection (TAAD) is a perplexing pathologic condition that can present surgical teams with the need to navigate a maze of complex decision-making. Ascending or hemi-arch replacement leaves behind a significant amount of distal diseased aortic tissue, which might have a persistent false lumen or primary or secondary intimal tears (or communications between lumina), which can lead to dilatation of the aortic arch. Unfavorable aortic remodeling is a major cause of distal aortic deterioration after the index surgery. Cardiac surgeons are aware of post-surgical cardiac chamber remodeling, but the concept of distal aortic remodeling is still idealized. The contemporary literature from established aortic centers supports aggressive management of the residual aortic pathology during the index surgery, and with continuing technical advancements, endovascular stenting options are readily available for patients with TAAD or for complicated type B aortic dissection cases. This review discusses the pathophysiology and treatment options for favorable distal aortic remodeling, as well as its impact on mid- to long-term outcomes following TAAD repair.

Endovascular Treatment of Post Type A Chronic Aortic Arch Dissection With a Branched Endograft: Early Results From a Retrospective International Multicenter Study

OBJECTIVE

The objective of this study was to evaluate the outcome of endovascular aortic arch repair for chronic dissection with a custom-made branched endograft.

BACKGROUND

Acute type A aortic dissections are often treated with prosthetic replacement of the ascending aorta. During follow-up, repair of an aneurysmal evolution of the false lumen distal to the ascending prosthesis can be a challenge both for the surgeon and the patient.

METHODS

We conducted a multicenter, retrospective study of consecutive patients from 14 vascular units treated with a custom-made, inner-branched device (Cook Medical, Bloomington, IN) for chronic aortic arch dissection. Rates of in-hospital mortality and stroke, technical success, early and late complications, reinterventions, and mortality during follow-up were evaluated.

RESULTS

Seventy consecutive patients were treated between 2011 and 2018. All patients were considered unfit for conventional surgery. In-hospital combined mortality and stroke rate was 4% (n = 3), including 1 minor stroke, 1 major stroke causing death, and 1 death following multiorgan failure. Technical success rate was 94.3%. Twelve (17.1%) patients required early reinterventions: 8 for vascular access complication, 2 for endoleak correction, and 2 for pericardial effusion drainage. Median follow-up was 301 (138-642) days. During follow-up, 20 (29%) patients underwent secondary interventions: 9 endoleak corrections, 1 open repair for prosthetic kink, and 10 distal extensions of the graft to the thoracic or thoracoabdominal aorta. Eight patients (11%) died during follow-up because of nonaortic-related cause in 7 cases.

CONCLUSIONS

Endovascular treatment of aortic arch chronic dissections with a branched endograft is associated with low mortality and stroke rates but has a high reintervention rate. Further follow-up is required to confirm the benefits of this novel approach.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Aortic Dissection and Other Acute Aortic Syndromes: Diagnostic Imaging Findings from Acute to Chronic Longitudinal Progression

Acute aortic dissection is the prototype of acute aortic syndromes (AASs), which include intramural hematoma, limited intimal tear, penetrating atherosclerotic ulcer, traumatic or iatrogenic aortic dissection, and leaking or ruptured aortic aneurysm. The manifestation is usually sudden and catastrophic with acutely severe tearing chest or back pain. However, clinical symptoms do not allow distinction between AAS types and other acute pathologic conditions. Diagnostic imaging is essential to rapidly confirm and accurately diagnose the type, magnitude, and complications of AASs. CT fast acquisition of volumetric datasets has become instrumental in diagnosis, surveillance, and intervention planning. Most critical findings affecting initial intervention and prognosis are obtained at CT, including involvement of the ascending aorta, primary intimal tear location, rupture, malperfusion, size and patency of the false lumen, complexity and extent of the dissection, maximum caliber of the aorta, and progression or postintervention complications. Involvement of the ascending aorta-Stanford type A-has the most rapid lethal complications and requires surgical intervention to affect its morbidity and mortality. Lesions not involving the ascending aorta-Stanford type B-have a lesser rate of complications in the acute phase. During the acute to longitudinal progression, various specific and nonspecific imaging findings are encountered, including pleural and pericardial effusions, fluid collections, progression including aortic enlargement, and postoperative changes that can be discerned at CT. A systematic analysis algorithm is proposed for CT of the entire aorta throughout the continuum of AASs into the chronic and posttreated disease state, which synthesizes and communicates salient findings to all care providers. Online supplemental material is available for this article. ^©RSNA, 2021.

The fate of residual aortic regurgitation after ascending aorta replacement in type A aortic dissection

OBJECTIVE

This study aimed to evaluate the changes in postoperative aortic regurgitation (AR) and determine the predictors of significant AR and root reoperation after ascending aortic replacement (AAR) in patients with acute type A aortic dissection.

METHODS

From January 1995 to December 2017, 271 consecutive patients underwent valve/root-preserving AAR (n = 225) and root replacement (n = 46). AR grade trend over time was analyzed by the ordinal mixed-effects model. Significant AR was defined as AR grade ≥3+ during the follow-up period. Predischarge and follow-up echocardiograms were obtained in 95.6% and 88.8% of enrolled patients, respectively.

RESULTS

At predischarge, postoperative ≥2+ AR was present in 20 (9.3%) and 1 (2.3%) patients in the AAR and root replacement groups, respectively. With increasing time after surgery, the grade of AR increased. At 10 years, 4.6% of patients had developed 3+ or 4+ AR. Considering death as the competing risk, the 10-year cumulative incidence of significant AR was significantly higher in the AAR than in the root replacement group (12.3% vs 2.2%; P = .047). The risk of root reoperation at 10 years was not different between the groups (P = .118). On Cox analysis, preoperative ≥3+ AR (P = .002), postoperative ≥2+ AR (P = .040), and false to true lumen ratio (P = .005) were associated predictors of significant AR.

CONCLUSIONS

Although valve/root-preserving AAR demonstrated reasonable long-term outcomes when compared with root replacement, preoperative ≥3+ AR, postoperative ≥2+ AR, and high false to true lumen ratio significantly increased the risk of significant AR. Therefore, careful echocardiographic surveillance may be warranted in patients with postoperative ≥2+ AR and small true lumen.

Total arch repair with frozen elephant trunk using the “zone 0 arch repair” strategy for type A acute aortic dissection

OBJECTIVE

The aim of this study was to investigate the effect of frozen elephant trunk deployment from the zone 0 aorta to the descending aorta on early and midterm postoperative results in patients with acute type A aortic dissection.

METHODS

Between October 2014 and April 2018, 108 patients underwent a combined strategy of frozen elephant trunk deployment, ascending aortic replacement, and arch vessel reconstruction ("zone 0 arch repair" strategy) for acute type A aortic dissection (excluding DeBakey type II). Of the 108 patients, 32 (29.6%) had primary tears of the aortic arch or descending aorta.

RESULTS

The 30-day mortality rate was 2.8% (3 patients), and in-hospital mortality rate was 6.5% (7 patients). New-onset permanent neurologic dysfunction and spinal cord injury occurred in 3.7% and 0% of patients, respectively. Five of the 101 survivors underwent thoracic endovascular aortic repair during hospitalization (2 for rapid false lumen enlargement; 3 for true lumen stenosis). The overall survival was 89.8%, 88.1%, and 88.1% at 1, 2, and 3 years, respectively. The cumulative incidence of distal aortic reintervention was 5.8%, 9.1%, and 9.1% at 1, 2, and 3 years, respectively. Two patients underwent thoracic endovascular aortic repair for distal aortic enlargement after discharge.

CONCLUSIONS

The use of the "zone 0 arch repair" strategy can eliminate the need for invasive aortic arch resection. It also eliminates the false lumen and produces satisfactory early and midterm postoperative results. Therefore, it can be an alternative to hemiarch and total arch replacements, which are based on a conventional "tear-oriented resection" strategy.

Risk factors of distal segment aortic enlargement after complicated type B aortic dissection

Objectives

Distal segment aortic enlargement (DSAE) is a common complication that influences the long-term prognosis of type B aortic dissection (TBAD) after thoracic endovascular aortic repair (TEVAR). In this study, a multivariate analysis was performed to find potential factors predictive of DSAE.

Methods

A single-center retrospective study was performed from 1999 to 2016. Included in the study were complicated TBAD patients who underwent TEVAR with uncovered residual tears. Based on the diameter of the distal segment of the uncovered aorta, we assigned patients to an enlargement group and a non-enlargement group. Data extracted from the medical records included demographic and clinical characteristics and follow-up computed tomography angiography data. The primary endpoints were the all-cause mortality and the presumably aortic-related events that required reintervention during the follow-up period.

Results

For the 333 patients, all-cause mortality was 38 (11.41%), and 76 (22.82%) patients underwent reintervention. A total of 70 (21.02%) patients experienced DSAE, among them were 2 patients who died of aortic rupture and 58 patients who accepted reintervention. Multivariate analysis reviewed independent risk factors of postoperative DSAE, including current smoking, the residual length of the patent false lumen, the postoperative number of dissection tears in the thoracic aorta and type III aortic arch; as well as protective factors, including the application of a restrictive bare stent (RBS), the length of covered stent in the descending thoracic aorta, and the distance from the residual first tear to the left subclavian artery (LSA).

Conclusion

DSAE after TEVAR for patients with a complicated TBAD can be influenced by their current smoking habit, the residual length of patent false lumen, the postoperative number of dissection tears in the thoracic aorta and the aortic arch type. Meanwhile, RBS usage, the length of the covered stent in the descending thoracic aorta and the distance from the residual first tear to the LSA could have positive effect on the prognosis.

Impact of ascending aortic, hemiarch and arch repair on early and long-term outcomes in patients with Stanford A acute aortic dissection

BACKGROUND:

Stanford A acute aortic dissection (AAD) is a life-threatening emergency associated with major morbidity and mortality. The aim of this study was to compare outcomes of three different surgical approaches in patients with Stanford A AAD.

METHODS:

From January 2006 to March 2015 a total of 240 consecutive patients with diagnosed Stanford A AAD underwent elective, isolated surgical aortic repair in our centre. Patients were divided into three groups according to the extent of surgical repair: isolated replacement of the ascending aorta, hemiarch replacement and total arch replacement. Patients were followed up for up to 9 years. After univariate analysis multinomial logistic regression was performed for subgroup analysis. Baseline characteristics and endpoints as well as long-term survival were analysed.

RESULTS:

There were no statistically significant differences among the three groups in terms of demographics and preoperative baseline and clinical characteristics. Incidence of in-hospital stroke ( p = 0.034), need for reopening due to bleeding ( p = 0.031) and in-hospital mortality ( p = 0.017) increased significantly with the extent of the surgical approach. There was no statistical difference in terms of long-term survival ( p = 0.166) among the three groups. Applying multinomial logistic regression for subgroup analysis significantly higher odds for stroke ( p = 0.023), reopening for bleeding ( p = 0.010) and in-hospital mortality ( p = 0.009) for the arch surgery group in comparison to the ascending aorta surgery group as well as significantly higher odds for stroke ( p = 0.029) for the total arch surgery group in comparison to the hemiarch surgery group were identified.

CONCLUSIONS:

With Stanford A AAD the incidence of perioperative complications increased significantly with the extent of the surgical approach. Subgroup analysis and long-term follow up in patients undergoing isolated ascending or hemiarch surgery showed a lower incidence of cerebrovascular events compared with surgery for total arch replacement.

Favorable Aortic Remodeling Following Serial False Lumen Procedures in a Case of Chronic Type IIIb Dissection

We report a case of acute type I aortic dissection in which an emergency graft replacement of the ascending aorta and innominate artery was performed. We performed false lumen thrombosis through hybrid thoracic endovascular aortic repair to seal the primary entry tear, followed by false lumen obliteration at the level of the descending thoracic aorta, abdominal aorta, and right common iliac artery. Over a period of 4.5 years, we used Amplatzer vascular plugs and coils based on our computed tomography angiography follow-up protocol.

Characteristics and Treatment Outcomes of Acute Type A Aortic Dissection With Elevated D-Dimer Concentration

Background

Clinical characteristics and treatment outcomes of acute type A aortic dissection with D‐dimer elevation have not been clarified.

Methods and Results

D‐dimer was measured preoperatively within 24 hours of symptom onset in 262 patients with acute type A aortic dissection. The median (and interquartile range) admission D‐dimer concentration in our total patient group was 26.7 (8.3–85.9) μg/mL. Median (interquartile range) D‐dimer concentrations were 5.0 (2.6–18.0) μg/mL for complete false lumen thrombosis (n=33), 60.9 (19.4–160.4) μg/mL for partial thrombosis (n=81), 26.5 (10.0–70.6) μg/mL for a patent false lumen (n=131), and 8.7 (3.2–26.9) μg/mL for ulcerlike projection (n=17) (P<0.01). With a D‐dimer concentration of ≤8.3 μg/mL representing the lower quartile, we then investigated predictors of a low D‐dimer level. Multivariate analysis showed dissection limited to the ascending aorta (P<0.01; odds ratio, 9.81) or descending aorta (P<0.01; odds ratio, 7.68), a completely thrombosed false lumen (P<0.01; odds ratio, 4.02), and absence of brain ischemia (P=0.013; odds ratio, 4.74) to be predictors of the lower D‐dimer concentration. Compared with patients with a low D‐dimer concentration (≤8.3 μg/mL, n=66), patients with a D‐dimer concentration >8.3 μg/mL (n=196) had a reduced preoperative platelet count and increased operation time and transfusion volume. In‐hospital mortality was elevated in this group (1.5% versus 11.2%; P=0.031), although 7‐year survival did not differ for hospital survivors (lower versus higher, 93.1% versus 79.1%; P=0.21).

Conclusions

D‐dimer concentrations are strongly influenced by the extent of dissection and false lumen status. Operative risks are increased in patients with a relatively high D‐dimer concentration.

Relationship between serum cortisol level and degree of false lumen thrombosis in patients with uncomplicated type B aortic dissection

Partial thrombosis of the false lumen in uncomplicated type B aortic dissection (uTBAD) is associated with an increased late mortality risk. Whether the serum cortisol level can affect false lumen thrombosis in patients with uTBAD has not been well characterized. This study was performed on 87 patients with uTBAD. A curve-fitting method was used to analyze the relationship between serum cortisol and partial thrombosis of false lumen. Univariate and multivariate logistic regression analyses were used to identify false lumen partial thrombosis–associated serum cortisol. Curve-fitting’s result revealed a characteristic U shape, and 14.0 µg/dL was considered as the cutoff point for serum cortisol. The results of univariate and multivariate logistic regression analyses suggested that when trisecting the serum cortisol level into three parts, the low and high levels of serum cortisol could significantly affect the occurrence of false lumen partial thrombosis compared with the middle level. The odds ratio value of the low and high levels of serum cortisol was 6.12 and 4.65, respectively, in the univariate analysis, and 24.32 and 3.93, respectively, in the multivariate analysis. Low or high levels of serum cortisol might influence the natural result of uTBAD through affecting the false lumen thrombosis.

Influence of False Lumen Status on the Prognosis of Acute Type A Aortic Dissection without Urgent Surgical Treatment

AIM

Recently, much attention has been focused on partial thrombosis of the false lumen in patients with acute aortic dissection. However, its effect on clinical outcomes in these patients, especially in case of acute type A aortic dissection, has not been clearly elucidated. This study evaluated the influence of the false lumen status, including partial thrombosis, on short-term clinical outcomes in acute type A aortic dissection patients without urgent surgical treatment.

METHODS

Sixty-two patients (29 males, mean age 73±13 years) with acute type A aortic dissection who did not receive urgent surgical treatment at four hospitals were enrolled. Patients were divided into three groups based on the false lumen status on enhanced computed tomography image (complete thrombosis, n=28; partial thrombosis, n=27; patent, n=7). Patients with partial thrombosis were further divided into two groups (thrombus-dominant, n=15; flow-dominant, n=12).

RESULTS

The short-term mortality rate (in-hospital and 30-day) was significantly higher in patients with a patent false lumen, while no significant difference was seen between the other two groups. Patients with flow-dominant partial thrombosis had significantly higher short-term mortality rate than those with thrombus-dominant partial thrombosis (in-hospital, p=0.001 and 30-day, p＜0.001).

CONCLUSIONS

The short-term mortality rate in acute type A aortic dissection patients without urgent surgical treatment was lower in patients with partial thrombosis of the false lumen than in those with a patent false lumen. Furthermore, patients with flow-dominant partial thrombosis had higher mortality rate than those with thrombus-dominant partial thrombosis.

Enlargement of aortic arch vessels after surgical repair of type A aortic dissection

BACKGROUND

Information on the growth rate of the diameter of the residual dissected supra-aortic trunk after surgical repair of type A aortic dissection is limited.

METHODS

We retrospectively reviewed 95 consecutive postsurgical patients with type A aortic dissection (acute, 91; chronic, 4) between 2005 and 2016 who were followed up with computed tomography. The diameter of the residual dissected supra-aortic trunk was measured by axial images and multiplanar reformatting, and the growth rate was calculated.

RESULTS

The mean age was 67.2 ± 12.8 years (range, 34-89 years). Forty-one brachiocephalic arteries (43%), 14 left common carotid arteries (15%), and 7 left subclavian arteries (10%) exhibited residual dissection. The diameter of the residual dissected branch with a patent false lumen (FL) gradually increased over time, whereas that with a thrombosed FL decreased and reached a plateau. The growth rate of brachiocephalic, left common carotid, and left subclavian arteries with a patent FL was 1.3 ± 1.2, 0.8 ± 0.3, and 0.6 ± 0.4 mm/y, respectively. One patient required surgical intervention for dilation of the brachiocephalic artery 8 years postoperatively. Multivariate analysis showed that male sex was an independent risk factor for a patent FL in the brachiocephalic artery (P = .0431; odds ratio, 2.04).

CONCLUSIONS

A residual dissected supra-aortic trunk with a thrombosed FL seems to be a benign condition. However, long-term follow-up is necessary for patients with a patent FL of residual dissected supra-aortic trunk, which might occasionally require surgical intervention.

Total Arch versus Hemiarch Replacement for Type A Acute Aortic Dissection: A Single-Center Experience

We retrospectively evaluated early and intermediate outcomes of aortic arch surgery in patients with type A acute aortic dissection (AAD), investigating the effect of arch surgery extension on postoperative results. From January 2006 through July 2013, 201 patients with type A AAD underwent urgent corrective surgery at our institution. Of the 92 patients chosen for this study, 59 underwent hemiarch replacement (hemiarch group), and 33 underwent total arch replacement (total arch group) in conjunction with ascending aorta replacement. The operative mortality rate was 22%. Total arch replacement was associated with a 33% risk of operative death, versus 15% for hemiarch (P=0.044). Multivariable analysis found these independent predictors of operative death: age (odds ratio [OR]=1.13/yr; 95% confidence interval [CI], 1.04-1.23; P=0.002), body mass index >30 kg/m² (OR=9.9; 95% CI, 1.28-19; P=0.028), postoperative low cardiac output (OR=10.6; 95% CI, 1.18-25; P=0.035), and total arch replacement (OR=8.8; 95% CI, 1.39-15; P=0.021) The mean overall 5-year survival rate was 59.3% ± 5.5%, and mean 5-year freedom from distal reintervention was 95.4% ± 3.2% (P=NS). In type A AAD, aortic arch surgery is still associated with high operative mortality rates; hemiarch replacement can be performed more safely than total arch replacement. Rates of distal aortic reoperation were not different between the 2 surgical strategies.

Prognostic implications of descending thoracic aorta dilation after surgery for aortic dissection

BACKGROUND

The present study assessed whether descending thoracic aorta growth can be measured reliably by volumetric analysis using multi-detector row computed tomography (MDCT) and whether growth influences the need for future aortic interventions in survivors of acute type A aortic dissection.

METHODS

A total of 51 patients (58 ± 11 years, 61% male) who underwent surgery for type A aortic dissection with ≥2 postoperative MDCT scans ≥5 months apart were included. Volumetric analysis of the descending thoracic aorta was performed with acceptable intraobserver variability. Growth of the complete, false and true lumen was estimated in ml/year and defined as slow growth (≤average growth) or fast growth (>average growth).

RESULTS

The complete lumen volume increased from 133 ± 8 ml to 163 ± 9 ml after 3.5 years follow-up (p < 0.001), with an average growth rate of 6.1 ml/year. The false lumen volume increased from 81 ± 7 ml to 106 ± 12 ml (p = 0.018) with an average growth rate of 2.8 ml/year. The true lumen changed only slightly from 59 ± 4 ml to 65 ± 8 ml (p = 0.205). Five-year freedom from descending thoracic aorta intervention was significantly lower in patients with above-average growth of the complete lumen (80 ± 9%) compared to slow growth (100%; p = 0.003). Similar observations were made for the false lumen (fast: 74 ± 12% vs. slow: 100%; p = 0.042).

CONCLUSIONS

Increased growth of the false lumen of the descending thoracic aorta after type A aortic dissection was associated with a higher risk of secondary interventions.

When and how to replace the aortic arch for type A dissection

Acute type A aortic dissection (AAAD) remains one of the most challenging diseases in cardiothoracic surgery and despite numerous innovations in medical and surgical management, early mortality remains high. The standard treatment of AAAD requires emergency surgery of the proximal aorta, preventing rupture and consequent cardiac tamponade. Resection of the primary intimal tear and repair of the aortic root and aortic valve are well-established surgical principles. However, the dissection in the aortic arch and descending untreated aorta remains. This injury is associated with the risk of subsequent false lumen dilatation potentially progressing to rupture, true lumen compression and distal malperfusion. Additionally, the dilatation of the aortic arch, the presence of a tear and retrograde dissection can all be considered indication for a total arch replacement in AAAD. In such cases a more aggressive strategy may be used, from the classic aortic arch operation to a single stage frozen elephant trunk (FET) technique or a two-stage approach such as the classical elephant trunk (ET) or the recent Lupiae technique. Although these are all feasible solutions, they are also complex and time demanding techniques requiring experience and expertise, with an in the length of cardiopulmonary bypass and both myocardial and visceral ischemia. Effective methods of cerebral, myocardial as well visceral protection are necessary to obtain acceptable results in terms of hospital mortality and morbidity. Moreover, a correct assessment of the anatomy of the dissection, through the preoperative angio CT scan, in addition to the clinical condition of the patients, remain the decision points for the best arch repair strategy to use in AAAD.

Descending endografts for type A dissections: con

An important goal of surgical repair of type A aortic dissection is to resect the intimal tear. Studies on the fate of residual dissection after acute type A aortic dissection repair in the past decade have driven surgeons to seek procedures to avoid distal reoperation. Aggressive surgical approach with total arch replacement in acute type A dissection has demonstrated lower incidence of distal reoperation and slower aortic growth rate compared to less aggressive ascending/hemiarch repair. Recently, successful results of thoracic endovascular aortic repair (TEVAR) in type B aortic dissection have encouraged surgeons to further attack acute type A aortic dissection with hybrid approach: antegrade endografting in the descending thoracic true lumen as an adjunct to hemiarch or total arch repair. However, is the hybrid approach with simultaneous descending endografting justified in all the acute type A aortic dissection cases? The outcomes of the hybrid approach reported by the several groups have demonstrated 80-100% of false lumen thrombus formation in the proximal descending aorta (stented segment); however, the complete obliteration of the false lumen is only 17-50%. The incidence of distal reoperation/reintervention after hybrid approach is as high as 14% and an adjunctive procedure is often performed. Moreover, there are concerns about additional risks associated with the hybrid procedures, such as spinal cord injury (SCI), stent graft induced new entry and stroke. The data on this new approach are still very limited. Hence, further study is warranted to prove its safety and durability.

False Lumen Status in Patients With Acute Aortic Dissection: A Systematic Review and Meta-Analysis

Background

The long‐term association between the status of the false lumen and poor patient outcomes in acute aortic dissection (AAD) remains unclear. This systematic review and meta‐analysis investigated whether the status of the false lumen was a predictor of poor long‐term survival in AAD.

Methods and Results

Eleven cohort studies (2924 participants) exploring the association between the false lumen status and long‐term outcomes (>1 year) in AAD were included. All studies reported multivariate‐adjusted hazard ratios (HRs) with 95% CIs for long‐term outcomes, according to false lumen status. Pooled HRs for mortality and aortic events were computed and weighted using generic inverse‐variance and random‐effect modeling. Residual patent false lumen was an independent predictor of long‐term mortality in AAD type A (HR, 1.71; 95% CI, 1.16–2.52; P=0.007) and type B (HR, 2.79; 95% CI, 1.80–4.32; P<0.001). AAD patients with residual patent false lumen exhibited an increased risk of aortic events (HR, 5.43; 95% CI, 2.95–9.99; P<0.001). Partial false lumen thrombosis was independently associated with long‐term mortality in type B AAD (HR, 2.24; 95% CI, 1.37–3.65; P=0.001). This association was not observed in AAD type A patients (HR, 1.75; 95% CI, 0.88–3.45; P=0.211).

Conclusions

The false lumen status influences late outcomes in AAD. Residual patent false lumen is independently associated with poor long‐term survival in AAD. However, only type B AAD patients with partial false lumen thrombosis had an increased late mortality risk.

Surgical treatment of complex aneurysms and thoracic aortic dissections with the Frozen Elephant Trunk technique

OBJECTIVE

Report initial experience with the Frozen Elephant Trunk technique.

METHODS

From July 2009 to October 2013, Frozen Elephant Trunk technique was performed in 21 patients (66% male, mean age 56 ± 11 years). They had type A aortic dissection (acute 9.6%, chronic 57.3%), type B (14.3%, all chronic) and complex aneurysms (19%). It was 9.5% of reoperations and 38% of associated procedures (25.3% miocardial revascularization, 25.3% replacement of aortic valve and 49.4% aortic valved graft). Aortic remodeling was evaluated comparing preoperative and most recent computed tomography scans. One hundred per cent of complete follow-up, mean time of 28 months.

RESULTS

In-hospital mortality of 14.2%, being 50% in acute type A aortic dissection, 8.3% in chronic type A aortic dissection, 33.3% in chronic type B aortic dissection and 0% in complex aneurysms. Mean times of cardiopulmonary bypass (152 ± 24 min), myocardial ischemia (115 ± 31 min) and selective cerebral perfusion (60 ± 15 min). Main complications were bleeding (14.2%), spinal cord injury (9.5%), stroke (4.7%), prolonged mechanical ventilation (4.7%) and acute renal failure (4.7%). The need for second-stage operation was 19%. False-lumen thrombosis was obtained in 80%.

CONCLUSION

Frozen Elephant Trunk is a feasible technique and should be considered. The severity of the underlying disease justifies high mortality rates. The learning curve is a reality. This approach allows treatment of more than two segments at once. Nonetheless, if a second stage is made necessary, it is facilitated.

Marfan syndrome is associated with recurrent dissection of the dissected aorta

BACKGROUND

Recurrent dissection of a previously dissected aortic segment has been reported as a rare, late complication in single case reports. The infrequency of this event makes informed risk assessment in an individual patient challenging.

METHODS

To investigate this issue we examined the database of the Massachusetts General Hospital Thoracic Aortic Center between January 1, 2003 and December 31, 2012. A retrospective review was performed to identify patients with both (1) an acute aortic dissection after a prior aortic dissection and (2) evidence of a new dissection within a previously dissected aortic segment creating a triple lumen aorta. Data were reviewed to identify factors predisposing to dissection of a previously dissected aortic segment.

RESULTS

Over a 10-year period we identified 5 cases of aortic dissection within a previously dissected aortic segment presenting as a new acute aortic syndrome. On average, the recurrent dissection occurred 1 decade after the first aortic dissection (mean = 9.8 ± 1.9 years). Patients identified in this series were significantly younger at first dissection and more likely to carry the diagnosis of Marfan syndrome. Aortic aneurysm diameter was quantified before and after the new dissection event and demonstrated a marked increase in aneurysmal size (mean increase = 1.6 ± 0.3 cm).

CONCLUSIONS

We conclude that medial degeneration, as seen in the Marfan aorta, represents a predisposing factor for recurrent dissection of the dissected aorta. Our data indicate that double aortic dissections cause significant arterial destabilization and a low threshold for surgical intervention is appropriate.

Clinical outcomes of combined aortic root reimplantation technique and total arch replacement

OBJECTIVES

The goal of this study was to evaluate early and late outcomes of combined valve-sparing aortic root replacement and total arch replacement (TAR).

METHODS

From October 1999 to May 2014, 195 patients underwent valve-sparing operations using the David reimplantation technique. Thirty-one patients underwent combined TAR for aortic regurgitation (AR) with extended aortic aneurysm from the aortic root to the aortic arch. Aetiologies included acute type A aortic dissection in 12 cases, chronic aortic dissection in 8 cases and non-dissecting aneurysm in 11 cases. There were 9 patients with Marfan syndrome. The preoperative severity of AR was mild in 4, moderate in 16 and severe in 11. Even though half of those were emergent operations for acute aortic dissection, preoperative haemodynamic conditions were stable in all patients.

RESULTS

No hospital deaths occurred. Postoperative complications included prolonged mechanical ventilation (>48 h) in 1 case and re-exploration for bleeding in 2 cases. Other complications, such as neurological dysfunction or low cardiac output syndrome, were not observed. At hospital discharge, 2 patients had mild AR, 22 had trace AR and 7 had no AR. During follow-up, 2 patients had moderate AR, 7 had mild AR, 18 had trace AR and 3 had no AR. Follow-up was completed in 95.1% of patients, and the mean follow-up period was 60.5 ± 9.1 months. No late death and thromboembolic complication occurred during follow-up. One patient required reoperation for AR. Freedom from reoperation at 5 and 10 years was 100 ± 0 and 83.3 ± 3.5%, respectively. Freedom from moderate or severe AR at 3 and 5 years was 83.3 ± 3.5 and 83.3 ± 3.5%, respectively.

CONCLUSIONS

Early outcomes of combined aortic root reimplantation and TAR were satisfactory and provided excellent freedom from thromboembolic complication. The rate of freedom from reoperation during long-term follow-up was acceptable. Further follow-up is required to evaluate this procedure.

Hybrid repair of type A acute aortic dissections with the Lupiae technique: ten-year results

OBJECTIVES

Replacing the ascending aorta and the arch in patients with type A acute aortic dissection achieves good short-term results, but several patients are left with distal intimal tears or a patent false lumen in the descending aorta. In this series, we report the 10-year experience with the Lupiae technique, a hybrid aortic repair technique for patients with type A acute aortic dissection.

METHODS

From 2003 to 2013, 89 patients with type A acute aortic dissections underwent replacement of the ascending aorta, the arch, and the rerouting of the neck vessels on the ascending aorta, creating a proximal Dacron landing zone for a completion with thoracic endovascular aortic repair if necessary.

RESULTS

In-hospital mortality was 8.9%. In 16 patients, the false lumen healed spontaneously, whereas the remaining 65 patients underwent thoracic endovascular aortic repair. One patient died after thoracic endovascular aortic repair. Eighty patients were followed up. Complete thrombosis of the false lumen was obtained in 93.8% of patients. The median follow-up was 46 ± 35 months. Overall 8-year survival was 93.7% ± 5%, 100% for patients with spontaneously healed residual false lumen after just type A acute aortic dissection repair and 92.3% ± 7.7% for patients who underwent thoracic endovascular aortic repair after type A acute aortic dissection repair. In 10 years, 1 patient underwent a reoperation on the distal aorta (1.25%).

CONCLUSIONS

The availability of a Dacron landing zone on the distal ascending aorta after type A acute aortic dissection repair allows the exclusion, with a thoracic endovascular aortic repair, of any residual intimal tear refilling a patent false lumen. This approach seems to be associated with a high probability of false lumen thrombosis and low rates of reoperations on the distal aorta.

Hybrid multistep approach to mega-aortic syndrome: the Lupiae technique

OBJECTIVES

Several techniques have been described for the treatment of thoraco-abdominal aneurysms in patients with mega-aortic syndrome (MAS), but the incidence of stroke, spinal cord injury and endoleaks remains significant. We present the mid-term results of a new hybrid, multistep technique to treat patients with MAS.

METHODS

From November 2005 to November 2012, 118 patients with MAS underwent surgical repair of thoracic and thoraco-abdominal aneurysms with the Lupiae technique. Fifty-five patients presented chronic aneurysms and 63 patients Type A acute dissections. Eighty-three patients underwent ascending aorta and arch replacement with a multibranched Dacron graft and epiaortic vessels rerouting (thoracic Lupiae procedure). Twenty patients had the thoracic Lupiae procedure plus partial visceral debranching (coeliac trunk and superior mesenteric artery [SMA]) through an upper mini-laparotomy. Fifteen patients had the thoracic Lupiae procedure plus a complete visceral debranching (coeliac trunk, SMA and renal arteries) using a second multibranched Dacron graft to replace the infrarenal aorta. All the patients with chronic aneurysms and 34 of 63 patients with Type A dissections underwent implant of endovascular stent grafts.

RESULTS

In-hospital mortality was 8.4%. No patients had stroke or spinal cord injury. The incidence of temporary renal failure was 5.2%. No patients presented endoleaks immediately and at follow-up CT scans. No death or reoperation occurred during the follow-up.

CONCLUSIONS

These results evidence that the Lupiae technique is a safe and effective option for the treatment of patients with MAS, achieving the complete exclusion of thoraco-abdominal aneurysms and of the residual false lumen in patients with acute aortic dissections.