Predictors of adverse outcome and transient neurological dysfunction following surgical treatment of acute type A dissections

A nomogram-based model to predict postoperative transient neurological dysfunctions in patients receiving acute type A aortic dissection surgery

The purposes of this study were to develop and validate a nomogram for predicting postoperative transient neurological dysfunctions (TND) in patients with acute type A aortic dissection (AAAD) who underwent modified triple-branched stent graft implantation. This retrospective study developed a nomogram-based model in a consecutive cohort of 146 patients. Patient characteristics, preoperative clinical indices, and operative data were analyzed. Univariate and multivariable analyses were applied to identify the most useful predictive variables for constructing the nomogram. Discrimination and the calibration of the model was evaluated through the receiver operating characteristic curve (ROC), the Hosmer-Lemeshow goodness-of-fit test and the decision curve analysis (DCA). At the same time, to identify and compare long-term cumulative survival rate, Kaplan-Meier survival curve was plotted. The incidence rate of postoperative TND observed in our cohort were 40.9%. Supra-aortic dissection with or without thrombosis, creatinine >115 μmol and albumin <39.7 g/L, selective antegrade cerebral perfusion (SACP) time >7 min and total operation time >303 min, were confirmed as independent predictors that enhanced the likelihood of TND. Internal validation showed good discrimination of the model with under the ROC curve (AUC) of 0.818 and good calibration (Hosmer-Lemeshow test, p > .05). DCA revealed that the nomogram was clinically useful. In the long-term survival there was no significant difference between patients with or without TND history. The results showed the predict model based on readily available predictors has sufficient validity to identify TND risk in this population, that maybe useful for clinical decision-making.

Impact of structural and process quality indicators on the outcomes of acute aortic dissection

OBJECTIVES

The mortality of acute aortic dissection (AAD) remains high, and evidence-to-practice gaps exist in real-world treatment. We explored the first quality indicators (QIs) for AAD management and evaluated the associations between the achievement of these QIs and the outcome in a nationwide administrative database.

METHODS

A systematic search was performed to establish initial index items for QIs. An evaluation was performed through an expert consensus meeting using the Delphi method. We studied 18 348 patients who had AAD (type A: 10 131; type B: 8217) in the Japanese Registry of All Cardiac and Vascular Diseases database between April 2012 and May 2015. The associations between the achievement of QIs [categorized into tertiles (low, middle and high)] and in-hospital mortality were determined by multivariable mixed logistic regression analyses.

RESULTS AND CONCLUSION

We developed a total of 9 QIs (5 structural and 4 process). Lower achievement rates of QIs were significantly associated with higher in-hospital mortality in both types [type A = middle: odds ratio (OR) 4.03; 95% confidence interval (CI) 3.301-4.90; P < 0.001; low: OR 15.68; 95% CI 11.67-21.06; P < 0.001 vs high; type B = middle: OR 3.48; 95% CI 2.19-5.53; P < 0.001; low: OR 7.79; 95% CI 4.65-13.06; P < 0.001 vs high]. Various sensitivity analyses showed consistent results. High achievement rates of QIs were significantly associated with reduced in-hospital mortality. Evaluating each hospital's management using QIs would help to equalize treatment quality and demonstrate the evidence-to-practice gaps in real-world treatments for AAD.

Cardiopulmonary bypass duration is an independent predictor of adverse outcome in surgical repair for acute type A aortic dissection

OBJECTIVE

This study aimed to investigate the relationship between the duration of cardiopulmonary bypass (CPB) and stroke or early death in patients with acute type A aortic dissection (ATAAD) receiving total aortic arch replacement with the frozen elephant trunk procedure (TAR with FET).

METHODS

A retrospective cohort study of 258 consecutive patients was conducted at Beijing Anzhen Hospital from December 2014 to June 2016. Patients who received TAR with FET for ATAAD were included. An adverse outcome (AO) was defined as 30-day mortality or stroke. Additionally, an AO was compared using propensity score matching.

RESULTS

The incidence of AO was 13.6% (n = 35). The 30-day mortality rate was 10.8% and the stroke rate was 9.3%. Patients were aged 47.9 ± 10.6 years old. The duration of CPB was an independent predictor of occurrence of AO after adjusting for confounding factors by multivariable logistic regression analysis (odds ratio 1.101, 95% confidence interval 1.003-1.208). In matched analysis, CPB duration remained a risk factor of AO.

CONCLUSIONS

The duration of CPB is an independent predictor of AO in surgical repair for ATAAD. The underlying mechanisms of this association are important for developing improved prevention strategies.

Stroke in acute type A aortic dissection: the Nordic Consortium for Acute Type A Aortic Dissection (NORCAAD)

OBJECTIVES

Stroke is a serious complication in patients with acute type A aortic dissection (ATAAD). Previous studies investigating stroke in ATAAD patients have been limited by small cohorts and have shown diverging results. We sought to identify risk factors for stroke and to evaluate the effect of stroke on outcomes in surgical ATAAD patients.

METHODS

The Nordic Consortium for Acute Type A Aortic Dissection database included patients operated for ATAAD at 8 Scandinavian Hospitals between 2005 and 2014.

RESULTS

Stroke occurred in 177 (15.7%) out of 1128 patients. Patients with stroke presented more frequently with cerebral malperfusion (20.6% vs 6.3%, P &lt; 0.001), syncope (30.6% vs 17.6%, P &lt; 0.001), cardiogenic shock (33.1% vs 20.7%, P &lt; 0.001) and pericardial tamponade (25.9% vs 14.7%, P &lt; 0.001) and more often underwent total aortic arch replacement (10.7% vs 4.7%, P = 0.016), compared to patients without stroke. In the 86 patients presenting with cerebral malperfusion, 38.4% developed stroke. Thirty-day and 5-year mortality in patients with and without stroke were 27.1% vs 13.6% and 42.9% vs 25.6%, respectively. Stroke was an independent predictor of early- [odds ratio 2.02, 95% confidence interval (CI) 1.34–3.05; P &lt; 0.001] and midterm mortality (hazard ratio 1.68, 95% CI 1.27–2.23; P &lt; 0.001).

CONCLUSIONS

Stroke in ATAAD patients is associated with increased early- and midterm mortality. Preoperative cerebral malperfusion and impaired haemodynamics, as well as total aortic arch replacement, were more frequent among patients who developed stroke. Importantly, a large proportion of patients presenting with cerebral malperfusion did not develop a permanent stroke, indicating that signs of cerebral malperfusion should not be considered a contraindication for surgery.

The use of cIMT as a predictor of postoperative stroke in patients undergoing surgical repair of acute type a aortic dissection

BACKGROUND

Acute type A aortic dissection (ATAAD) is a life-threatening condition that requires surgical intervention. Stroke remains an extremely serious adverse outcome that can occur in ATAAD patients undergoing aortic arch repair, leading to higher rates of patient mortality and decreased postoperative quality of life. In the present study, we sought to determine whether carotid intima-media thickness (cIMT) is a reliable predictor of postoperative stroke risk.

MATERIALS AND METHODS

This was a prospective study of 76 patients with ATAAD undergoing aortic arch repair. For all patients, cIMT was determined preoperatively through a Doppler-based method. Incidence of different forms of neurological dysfunction, including temporary neurological dysfunction (TND) and stroke, was monitored in these patients, and the relationship between cIMT and stroke incidence was assessed using a receiver-operating characteristic (ROC) curve. Prognostic variables associated with stroke risk were further identified through univariate and multivariate analyses.

RESULTS

A total of 26/76 (34.2%) patients in the present study suffered from neurological dysfunction, of whom 16 (21.0%) suffered from TND and 10 (13.2%) suffered a stroke. The remaining 50 patients (65.8%) did not suffer from neurological dysfunction. The cIMT values in the stroke, TND, and neurological dysfunction-free patients in this study were 1.12 ± 0.19 (mm), 0.99 ± 0.13 (mm), and 0.87 ± 0.13 (mm), respectively. A total of 4 patients in this cohort died during the study, including 1 in the TND group and 3 in the stroke group. An ROC curve analysis indicated that cIMT could predict stroke with an area under the curve value of 0.844 (95% CI, 0.719-0.969; p < 0.001). A multivariate analysis revealed that cIMT > 0.9 mm was independently associated with stroke risk (p = 0.018).

CONCLUSION

We found that cIMT can be used to predict postoperative stroke risk in ATAAD patients undergoing aortic arch repair, with a cIMT > 0.9 mm coinciding with increased stroke risk in these patients.

TRIAL REGISTRATION

ChiCTR1900022289. Date of registration 4 April 2019 retrospectively registered.

Identification of CTA-Based Predictive Findings for Temporary and Permanent Neurological Dysfunction after Repair in Acute Type A Aortic Dissection

The aim of this study was to determine CT risk findings predictive of temporary neurological dysfunction (TND) and permanent neurological dysfunction (PND) after surgical repair for acute type A aortic dissection (ATAAD). A total of 255 patients (41 ± 16 years, 79% male) with ATAAD underwent aortic CT angiography (CTA) and surgical repair consecutively from January 2013 to June 2016. The CTA findings of the 255 patients for the thoracic aorta and carotid artery were analysed to identify risk factors predictive of TND and PND. Thirty-eight patients (15%) suffered TND, and 18 (7%) exhibited PND. Common carotid artery (CCA) dissection (OR = 4.63), lower enhancement of unilateral ICA (OR = 3.02) and aortic arch tears (OR = 2.83) were predictors of postoperative TND, while PND was best predicted by retrograde ascending aorta (aAO) dissection (OR = 5.62) and aortic arch tears (OR = 6.74). In CCA dissection, the extent of the entire CCA and proximal ICA (P = 0.014), a low-enhancement false lumen with re-entry (P = 0.000) and a severely narrowed true lumen without re-entry (P = 0.005) significantly increased the risk of postoperative TND. In patients with ATAAD, specific CT findings allow the individual risk of postoperative TND and PND to be identified and may guide subsequent surgical management.

Bilateral versus unilateral antegrade cerebral perfusion in total arch replacement for type A aortic dissection

BACKGROUND

Antegrade cerebral perfusion (ACP) is the most widely used cerebral protection strategy for complex aortic repair and includes unilateral (u-ACP) and bilateral (b-ACP) techniques. The superiority of b-ACP over u-ACP has been the subject of much debate. Focusing on type A aortic dissection requiring total arch replacement, we investigated the clinical effects of b-ACP versus u-ACP.

METHODS

Between September 2006 and August 2014, 203 patients presenting with type A aortic dissection (median age, 51.0 ± 13 years; range, 17-72 years; 128 males) underwent total aortic arch replacement with hypothermic circulatory arrest. ACP was used in all patients, including u-ACP in 82 (40.3%) and b-ACP in 121 (59.7%).

RESULTS

There was no significant difference between the u-ACP and b-ACP groups in terms of cardiopulmonary bypass (CPB) time, cross-clamp time, or circulatory arrest time. Overall 30-day mortality was comparable in the 2 groups (11.6% for b-ACP vs 20.7% for u-ACP; P = .075). The prevalence of postoperative permanent neurologic dysfunction (PND) was comparable as well (8.4% vs 16.9%; P = .091). Mean ventilation time was lower in the b-ACP group (95.5 ± 45.25 hours vs 147.0 ± 82 hours; P < .001). Mean lengths of stay in the intensive care unit and the hospital overall were comparable in the 2 groups (intensive care unit: 16 ± 17.75 days vs 17 ± 11.5 days, P = .454; hospital: 26.5 ± 20.6 days vs 24.8 ± 10.3 days, P = .434). The P values from logistic regression models indicated that in the 2 groups combined, CPB time and circulatory arrest time were independent risk factors for both mortality and PND.

CONCLUSIONS

In this, the first published study focusing on the efficacy of u-ACP and b-ACP in total arch replacement for type A aortic dissection, the b-ACP group did not demonstrate significantly lower 30-day mortality or PND rate compared with the u-ACP group. Future large-sample studies are warranted to thoroughly examine this critical issue.

How to Perfuse: Concepts of Cerebral Protection during Arch Replacement

Arch surgery remains undoubtedly among the most technically and strategically challenging endeavors in cardiovascular surgery. Surgical interventions of thoracic aneurysms involving the aortic arch require complete circulatory arrest in deep hypothermia (DHCA) or elaborate cerebral perfusion strategies with varying degrees of hypothermia to achieve satisfactory protection of the brain from ischemic insults, that is, unilateral/bilateral antegrade cerebral perfusion (ACP) and retrograde cerebral perfusion (RCP). Despite sophisticated and increasingly individualized surgical approaches for complex aortic pathologies, there remains a lack of consensus regarding the optimal method of cerebral protection and circulatory management during the time of arch exclusion. Many recent studies argue in favor of ACP with various degrees of hypothermic arrest during arch reconstruction and its advantages have been widely demonstrated. In fact ACP with more moderate degrees of hypothermia represents a paradigm shift in the cardiac surgery community and is widely adopted as an emergent strategy; however, many centers continue to report good results using other perfusion strategies. Amidst this important discussion we review currently available surgical strategies of cerebral protection management and compare the results of recent European multicenter and single-center data.

The outcome of surgical management of type A aortic dissection

BACKGROUND

Type A aortic dissection is a serious and fatal condition.

METHODS

We retrospectively evaluated the outcome following repair of ascending aortic dissection in a contemporary cohort of 108 patients with a mean age of 59.5 ± 13.8 years, who were treated between 2006 and 2011. Most patients were male (70, 65%).

RESULTS

Circulatory arrest with a mean duration of 22 ± 16 min was performed in 42 (38.9%) patients. Perioperative mortality was 15.7% (n = 17). Univariate analysis showed that cardiopulmonary bypass time (p = 0.0006), age >60 years (p = 0.028), cardiogenic shock at presentation (p = 0.02), New York Heart Association class II-IV (p = 0.038), hemopericardium (p = 0.0035), and preoperative cerebrovascular accident (p = 0.02) were predictors of mortality. Multivariate analysis indicated that age >60 years (odds ratio 7.7, 95% confidence interval: 1.52-38.96, p = 0.0136), preoperative cerebrovascular accident (odds ratio 25.2, 95% confidence interval: 2.45-258.9, p = 0.0066), hemopericardium (odds ratio 41.6, 95% confidence interval: 5.38-320.7, p = 0.0003), and cardiopulmonary bypass time (odds ratio 1.85, 95% confidence interval: 1.32-2.57, p = 0.0003) were independent predictors of perioperative mortality. The 1- and 4-year survival was 80% ± 3.8% and 69% ± 5.7%, respectively. Age >60 years (hazard ratio 3.3, 95% confidence interval: 1.4-7.9, p = 0.0064) was the only independent predictor of long-term mortality.

CONCLUSION

Our results identify the major risk factors for perioperative and long-term mortality. Age is an independent risk factor for mortality.

Intestinal mast cells mediate gut injury and systemic inflammation in a rat model of deep hypothermic circulatory arrest

OBJECTIVE

Cardiac surgery, especially when employing cardiopulmonary bypass and deep hypothermic circulatory arrest, is associated with systemic inflammatory responses that significantly affect morbidity and mortality. Intestinal perfusion abnormalities have been implicated in such responses, but the mechanisms linking local injury and systemic inflammation remain unclear. Intestinal mast cells are specialized immune cells that secrete various preformed effectors in response to cellular stress. We hypothesized that mast cells are activated in a microenvironment shaped by intestinal ischemia/reperfusion, and investigated local and systemic consequences.

DESIGN

Rat model of deep hypothermic circulatory arrest.

SETTING

University research laboratory.

SUBJECTS

Twelve- to 14-week-old male Sprague-Dawley rats.

INTERVENTIONS

Rats were anesthetized and cooled to 16°C to 18°C on cardiopulmonary bypass before instituting deep hypothermic circulatory arrest for 45 minutes. Specimens were harvested following rewarming and 2 hours of recovery.

MEASUREMENTS AND MAIN RESULTS

Significant intestinal barrier disruption was found, together with macro- and microscopic evidence of ischemia/reperfusion injury in ileum and colon, but not in the lungs or kidneys. Immunofluorescence and toluidine blue staining revealed increased numbers of mast cells and their activation in the gut. In animals pretreated with the mast cell stabilizer, cromolyn sodium, mast cell degranulation was blocked, and intestinal morphology and barrier function were preserved following deep hypothermic circulatory arrest. Furthermore, cromolyn sodium treatment was associated with reduced intestinal neutrophil influx and blunted systemic release of proinflammatory cytokines.

CONCLUSION

Our data provide primary evidence that intestinal ischemia/reperfusion is a leading pathophysiologic process in a rat model of deep hypothermic circulatory arrest, and that intestinal injury, and local and systemic inflammatory responses are critically dependent on mast cell activation. This identifies intestinal mast cells as central players in deep hypothermic circulatory arrest-associated responses, and opens novel therapeutic possibilities for patients undergoing this procedure.

Characteristics and in-hospital outcomes of patients with cardiac tamponade complicating type A acute aortic dissection

Cardiac tamponade (TMP) is a life-threatening complication of acute type A aortic dissection (AAD). The purpose of this study was to assess the clinical characteristics and in-hospital outcomes of TMP in the setting of AAD on the basis of the findings in the large cohort of the International Registry of Acute Aortic Dissection (IRAD). Six hundred seventy-four patients (mean age 61.8 +/- 14.2 years) with AAD in IRAD were studied. TMP was suspected on clinical grounds and confirmed by diagnostic imaging. Univariate testing was followed by multivariate logistic regression analysis to determine the association of TMP. TMP was detected in 126 patients with AAD (18.7%). Age did not differ between patients with and without TMP. Those with TMP less often had previous cardiac surgery (7.0% vs 17.1%, p = 0.007). Syncope (37.8% vs 13.7%, p <0.0001) and altered mental status (31.2% vs 10.6%, p <0.0001) were more common in patients with AAD with TMP than without TMP. Patients with TMP were more likely to have widened mediastina on chest x-ray (72.6% vs 60.3%, p = 0.02) and to have periaortic hematomas (44.7% vs 21.2%, p <0.0001). In-hospital outcomes were significantly worse in patients with TMP. The mortality of patients with TMP remained significantly higher, even after adjustment for baseline clinical characteristics (p <0.001). On logistic regression, altered mental status, hypotension, and early mortality were identified as independent correlates of TMP. In conclusion, TMP is not uncommon in patients with AAD. Syncope, altered mental status, and a widened mediastinum on chest x-ray on presentation suggest TMP, the presence of which warrants urgent operative therapy to improve outcome.

Major Clinical Outcomes in Adults Undergoing Thoracic Aortic Surgery Requiring Deep Hypothermic Circulatory Arrest: Quantification of Organ-Based Perioperative Outcome and Detection of Opportunities for Perioperative Intervention

OBJECTIVE

The purpose of this study was to describe clinical outcome after adult thoracic aortic surgery requiring standardized deep hypothermic circulatory arrest (DHCA), to determine mortality and length of stay, neurologic outcome, cardiorespiratory outcome, and hemostatic and renal outcome after DHCA.

DESIGN

Retrospective and observational.

SETTING

Cardiothoracic operating rooms and intensive care unit (ICU).

PARTICIPANTS

All adults requiring thoracic aortic repair with DHCA.

INTERVENTIONS

None. The study was observational.

MAIN RESULTS

The cohort size was 110. All patients received an antifibrinolytic. The mortality rate was 8.2%. The mean length of stay was 6.8 days (ICU) and 14.0 days (hospital). The incidence of stroke was 8.1% and postoperative delirium was 10.9%. The rate of postoperative atrial fibrillation was 43.6%; 19.1% required postoperative mechanical ventilation longer than 72 hours. Chest tube drainage was 931 mL for the first 24 hours. Postoperative dialysis was required in 1.8% of patients. Renal dysfunction occurred in 40% to 50% of patients, depending on the definition.

CONCLUSIONS

The protocol for DHCA at the authors' institution is associated with superior or equivalent perioperative outcomes to those reported in the literature. This study identified the need for further quantification of the clinical outcomes after DHCA in order to prioritize outcome-based hypothesis-driven prospective intervention in DHCA.