Management of common carotid artery dissection due to extension from acute type A (DeBakey I) aortic dissection

A comparison of bilateral and unilateral cerebral perfusion for total arch replacement surgery for non-marfan, type A aortic dissection

OBJECTIVES

Acknowledging lacking of consensus exist in total aortic arch (TAA) surgery for acute type A aortic dissection (AAD), this study aimed to investigate the neurologic injury rate between bilateral and unilateral cerebrum perfusion on the specific population.

METHODS

A total of 595 AAD patients other than Marfan syndrome receiving TAA surgery since March 2013 to March 2022 were included. Among them, 276 received unilateral cerebral perfusion (via right axillary artery, RCP) and 319 for bilateral cerebral perfusion (BCP). The primary outcome was neurologic injury rate. Secondary outcomes were 30-day mortality, serum inflammation response (high sensitivity C reaction protein, hs-CRP; Interleukin-6, IL-6; cold-inducible RNA binding protein, CIRBP) and neuroprotection (RNA-binding motif 3, RBM3) indexes.

RESULTS

The BCP group reported a significantly lower permanent neurologic deficits [odds ratio: 0.481, Confidence interval (CI): 0.296-0.782, p = 0.003] and 30-day mortality (odds ratio: 0.353, CI: 0.194-0.640, p < 0.001) than those received RCP treatment. There were also lower inflammation cytokines (hr-CRP: 114 ± 17 vs. 101 ± 16 mg/L; IL-6: 130 [103,170] vs. 81 [69,99] pg/ml; CIRBP: 1076 [889, 1296] vs. 854 [774, 991] pg/ml, all p < 0.001), but a higher neuroprotective cytokine (RBM3: 4381 ± 1362 vs 2445 ± 1008 pg/mL, p < 0.001) at 24 h after procedure in BCP group. Meanwhile, BCP resulted in a significantly lower Acute Physiology, Age and Chronic Health Evaluation (APACHE) Ⅱscore (18 ± 6 vs 17 ± 6, p < 0.001) and short stay in intensive care unit (4 [3,5] vs. 3 [2,3] days, p < 0.001) and hospital (16 ± 4 vs 14 ± 3 days, p < 0.001).

CONCLUSIONS

This present study indicated that BCP compared with RCP was associated with lower permanent neurologic deficits and 30-day mortality in AAD patients other than Marfan syndrome receiving TAA surgery.

Management of compromised bilateral carotid artery flow in acute type A aortic dissection, in a neurologically intact patient

Type A aortic dissection (TAAD) is a disease that can have a cataclysmic impact on a patient's life, and early surgical intervention is crucial for survival. Cerebral malperfusion occurs in 6-14% of TAAD patients, primarily from partial or complete blockage of the arch vessels by the dissection flap, and hypoxic brain injury secondary to tamponade or shock and/or brain embolism from thrombosis of the false lumen. Management protocols for concomitant carotid arterial dissection in TAAD patients are inconsistent in the current literature. Through this case report, we have tried to describe our easily replicable strategies to manage bilateral carotid artery involvement in TAAD, avoiding total circulatory arrest (TCA), in a neurologically intact patient with good neurological outcome.

Stroke After Acute Type A Dissection Repair Using Right Axillary Cannulation First Approach

BACKGROUND

This study sought to analyze the details of strokes after acute type A dissection repair (ATAD) using a right axillary artery (RAX) first approach.

METHODS

A total of 356 consecutive ATAD repairs from 2005 to 2022 were analyzed on the basis of arterial cannulation site. Strokes were evaluated by head computed tomography.

RESULTS

The rate of RAX cannulation was 82.6% (n = 294), with a 38.2% rate of antegrade cerebral perfusion use, both of which had increased over the years. The non-RAX group had more cardiogenic shock (RAX, 16.3% vs non-RAX, 37.1%; P < .001), cerebral malperfusion (8.8% vs 25.8%, respectively; P < .001), and innominate artery dissection (45.9% vs 69.2%, respectively; P = .007). Eight patients died before undergoing a full neurologic assessment. The overall stroke rate was 8.4% (n = 30), and it was lower in the RAX group (5.1% vs 24.2%; P < .001). All strokes were ischemic, with concomitant hemorrhagic strokes occurring in 6 patients. Strokes diagnosed immediately after surgery (perioperative stroke) accounted for 70% (n = 21 of 30) of cases. Strokes predominantly affected the right anterior circulation (right anterior, 80% vs left anterior, 46.7% vs left posterior, 26.7%; P = .013), independent of arterial cannulation site. The proposed mechanism of perioperative strokes was not uniform (embolism, 33.3%; hypoperfusion, 42.8%; embolism and hypoperfusion, 14.3%; lacunar infarct, 10%), whereas most postoperative strokes were embolic (77.8%). The mean National Institutes of Health Stroke Scale score was 20.6 ± 9.9, and the modified Rankin score at discharge was 4.1±2.2.

CONCLUSIONS

Most strokes in ATAD occurred perioperatively from various mechanisms predominantly affecting the right anterior circulation irrespective of the arterial cannulation site. This complication is most likely the result of unstable hemodynamics and dissection of the innominate artery (IA) or its downstream vessels.

Effect of Asymptomatic Common Carotid Artery Dissection on the Prognosis of Patients With Acute Type A Aortic Dissection

BACKGROUND

Acute type A aortic dissection can extend upwards to involve the common carotid artery. However, whether asymptomatic common carotid artery dissection (CCAD) requires surgical repair remains controversial. This study aimed to explore the effect of asymptomatic CCAD without surgical intervention on the prognosis of patients who underwent surgery for acute type A aortic dissection.

METHODS AND RESULTS

Between January 2015 and December 2017, 485 patients with no neurological symptoms who underwent surgery for acute type A aortic dissection were enrolled in this retrospective cohort study. The patients were divided into 2 groups based on the exposure factor of CCAD. CCAD was detected in 111 patients (22.9%), and after adjusting baseline data (standardized mean difference <0.1), the 30-day mortality (17.1% versus 6.0%, P<0.001) and incidence of fatal stroke (7.7% versus 1.6%, P=0.001) were significantly higher in the group with CCAD. Univariable and multivariable Cox regression analyses found CCAD as an independent risk factor for 30-day mortality (hazard ratio [HR], 2.8 [95% CI, 1.5-5.2]; P=0.001). At a median follow-up of 6.2 years (interquartile range, 5.6-6.9 years), landmark analysis with a cutoff value of 1 month postoperatively showed a significant increase in mortality in the group with CCAD, especially in the first month (log-rank P=0.002) and no significant difference in survival after the first month postoperatively between the 2 groups (log-rank P=0.955).

CONCLUSIONS

Asymptomatic CCAD increased the risk of early fatal stroke and death in patients with acute type A aortic dissection after surgery but did not affect midterm survival in patients who survived the early postoperative period.

Cerebral protection strategies for type A aortic dissection repair

Importance

Techniques to preserve neurological function during type A aortic dissection repairs have been broadly discussed in the literature and heavily debated. Despite the effectiveness of various approaches, a consensus lacks on how to maintain optimal cerebral temperature during surgery. This review examines the three predominant cerebral protection strategies in aortic arch reconstructions: straight deep hypothermic circulatory arrest (sDHCA), retrograde cerebral perfusion (RCP), and antegrade cerebral perfusion (ACP).

Observations

The signature characteristics of sDHCA, RCP, and ACP are similar-hypothermia, with or without cerebral perfusion. Employing cerebral perfusion techniques may prolong operative times, while ACP permits operation at higher body temperatures, albeit with restricted operative durations.

Conclusion

For type A dissection arch reconstructions, sDHCA, RCP, and ACP can be successfully implemented. Factors such as operative times and individual patient conditions should be considered when choosing a cerebral protection strategy.

Cerebral infarction and risk factors in acute type A aortic dissection with arch branch extension

OBJECTIVE

Stanford type A aortic dissection (AAD) may affect the supra-aortic arteries, which are associated with acute ischemic stroke (AIS) or transient ischemic attack (TIA). This study aimed to investigate cerebral perfusion, the infarction incidence and risk factors in AAD patients.

METHODS

A total of 156 consecutive AAD patients were enrolled and divided into two groups according to whether the aortic arch branches were involved: the affected group (n = 90) and the unaffected group (n = 66). Clinical, echocardiographic/carotid Doppler data and cerebral infarction morbidity were compared between the groups. Independent predictors of 30-day AAD mortality were identified through multivariable Cox regression, and perioperative risk factors were analyzed.

RESULTS

In total, 57.7% of AAD patients had aortic arch branch involvement. Abnormal Doppler waveforms were more common in the affected group (p < 0.05). Regarding intracranial perfusion, the blood flow volumes (BFVs) of the bilateral internal carotid arteries (ICAs) and right vertebral artery (RVA) in the affected group were significantly reduced (p < 0.05). The incidence of cerebral infarction in the affected group was significantly higher than that in the unaffected group (35.6% vs. 19.7%, p = 0.031). Multivariable analysis revealed that age >45 years old, right internal carotid artery (RICA) involvement and reduced left ventricular ejection fraction (LVEF) were significant predictors of perioperative death.

CONCLUSIONS

Aortic arch branch involvement is common in patients with AAD and is associated with reduced cerebral blood flow (especially on the right side) and a higher incidence of cerebral infarction. Age, extension of the RICA dissection and LVEF impairment are independent risk factors for AAD-related death.

Craniocervical Artery Dissections: A Concise Review for Clinicians

Craniocervical artery dissection (CAD), although uncommon, can affect the young and lead to devastating complications, including stroke and subarachnoid hemorrhage. It starts with a tear in the intima of a vessel with subsequent formation of an intramural hematoma. Most CAD occurs spontaneously or after minor trauma. Patients with CAD may exhibit isolated symptoms of an underlying subclinical connective tissue disorder or have a clinically diagnosed connective tissue disorder. Emergent evaluation and computed tomography angiography or magnetic resonance imaging/angiography of the head and neck are required to screen for and to diagnose CAD. Carotid ultrasound is not recommended as an initial test because of limited anatomic windows; diagnostic catheter-based angiography is reserved for atypical cases or acutely if severe neurologic deficits are present. Patients with CAD can present with focal neurologic deficits due to ischemia (thromboembolism or arterial occlusion) or subarachnoid hemorrhage (pseudoaneurysm formation and rupture). Also common are local symptoms, such as head and neck pain, pulsatile tinnitus, Horner syndrome, and cranial neuropathy, or cervical radiculopathy from mass effect. Acute management of transient ischemic attack/stroke in CAD is not different from the management of ischemic stroke of other causes. Patients with CAD need long-term antithrombotic therapy for secondary stroke prevention. Anticoagulation or dual antiplatelet therapy followed by single antiplatelet therapy is recommended for extracranial CAD and antiplatelet therapy for intracranial CAD. Recurrent ischemic events and dissections are rare and typically occur early. Patients with CAD should avoid deep neck massage or chiropractic neck manipulation involving sudden excessive, forced neck movements.

The Construction of a Risk Prediction Model Based on Neural Network for Pre-operative Acute Ischemic Stroke in Acute Type A Aortic Dissection Patients

Objective: To establish a pre-operative acute ischemic stroke risk (AIS) prediction model using the deep neural network in patients with acute type A aortic dissection (ATAAD). Methods: Between January 2015 and February 2019, 300 ATAAD patients diagnosed by aorta CTA were analyzed retrospectively. Patients were divided into two groups according to the presence or absence of pre-operative AIS. Pre-operative AIS risk prediction models based on different machine learning algorithm was established with clinical, transthoracic echocardiography (TTE) and CTA imaging characteristics as input. The performance of the difference models was evaluated using the receiver operating characteristic (ROC), precision-recall curve (PRC) and decision curve analysis (DCA). Results: Pre-operative AIS was detected in 86 of 300 patients with ATAAD (28.7%). The cohort was split into a training (211, 70% patients) and validation cohort (89, 30% patients) according to stratified sampling strategy. The constructed deep neural network model had the best performance on the discrimination of AIS group compare with other machine learning model, with an accuracy of 0.934 (95% CI: 0.891-0.963), 0.921 (95% CI: 0.845-0.968), sensitivity of 0.934, 0.960, specificity of 0.933, 0.906, and AUC of 0.982 (95% CI: 0.967-0.997), 0.964 (95% CI: 0.932-0.997) in the training and validation cohort, respectively. Conclusion: The established risk prediction model based on the deep neural network method may have the big potential to evaluate the risk of pre-operative AIS in patients with ATAAD.

Direct Axillary Artery Cannulation for Type A Dissection and Impact of Dissected Innominate Artery

BACKGROUND

This study seeks to assess the safety of direct axillary artery (AX) cannulation for acute type A dissection (ATAD) repair, including the impact of innominate artery dissection (IAD).

METHODS

Of 281 consecutive patients who underwent ATAD repair from 2007 to 2020, preoperative computed tomography was available in 200 (IAD: N=101, non-IAD N=99). IAD with compromised true lumen was defined as dissection in which the false lumen was greater than 50% of the IA diameter (N=75/101).

RESULTS

AX cannulation was attempted in 188 patients (94.0%), with a 1.6% vascular injury rate (3 patients; bypass to the distal AX: 2 patients, and local dissection: 1 patient). Most patients (89.5%) underwent hemiarch replacement using deep hypothermic circulatory arrest for the distal repair. Right AX cannulation was used in 80.2% of patients with IAD and in 88.9% without IAD (p=0.075). Patients with IAD had more cerebral (21.8%vs. 5.1%, p=0.001) and arm malperfsion (11.9% vs.4.0%, p=0.075). Operative mortality and stroke were comparable between Non-IAD and IAD groups (8.1% vs. 7.9%, p=1.00 and 4.0% vs. 5.3%, p=0.689). The right AX was successfully used in 77.3% of IAD patients having a compromised true lumen, with comparable hospital outcomes to non-compromised IAD patients. Upper extremity malperfusion, multi-organ malperfusion, low ejection fraction, and female gender were predictors for non-right AX cannulation.

CONCLUSIONS

Routine direct AX cannulation strategy is safe in ATAD repair. Right AX cannulation can be used in most patients with IAD, even with a compromised true lumen, with low mortality, stroke and vascular injury rates.

Carotid Artery Stenting for Symptomatic Carotid Artery Dissection Developing from Stanford Type A Aortic Dissection: A Report of Two Cases

Objective

Stanford type A acute aortic dissection (AAD) is associated with carotid artery dissections (CADs). We report two cases of carotid artery stenting (CAS) for symptomatic CAD after ascending aortic replacement (AAR) for AAD.

Case Presentation

Case 1: A 51-year-old man with AAD was transferred to our institute. He had no notable paralysis symptoms on initial presentation. However, after AAR for AAD was performed, left paralysis developed within a few hours. Emergency angiography revealed right CAD and pseudo-occlusion. CAS was performed successfully using intravascular ultrasound (IVUS). He was transferred to a rehabilitation hospital with a modified Rankin Scale (mRS) score of 2.Case 2: A 55-year-old man underwent AAR for AAD, but asymptomatic left CAD remained. Two weeks after the operation, he presented with slight signs of aphasia. Aspirin was prescribed and follow-up was performed, but his symptoms did not improve. He underwent magnetic resonance imaging in our department, which revealed acute cerebral infarction on the left pars opercularis and an artery-to-artery embolism from CAD. CAS was performed via the retrograde approach with direct puncture of the normal left common carotid artery using IVUS. He was discharged with no complications and a mRS score of 1.

Conclusion

IVUS can be useful for CAS to confirm the true lumen and extension of long CAD lesions developing from AAD.

Type A aortic dissection: involvement of carotid artery and impact on cerebral malperfusion

Acute type A aortic dissection is a surgical emergency and management of such pathology can be complex with poor outcomes when there is organ malperfusion. Carotid artery involvement is present in 30% of patients diagnosed with acute type A aortic dissection, and given its emergency and complex nature, there is much controversy regarding the approach, extent of treatment, and timing of the intervention. It is clear that the occurrence of cerebral malperfusion adds an extra layer of complexity to the decision-making framework for treatment. Standardization and validation of the optimal management approach is required, and this should ideally be addressed with large-scale studies. Nonetheless, current literature supports the need for rapid recognition and diagnosis of acute type A aortic dissection with cerebral malperfusion, immediate and extensive surgical repair, and the appropriate use of cerebral perfusion techniques. This paper aims to discuss the current evidence regarding the impact of carotid artery involvement in both the management and outcomes of acute type A aortic dissection.

Outcomes of Carotid Artery Replacement With Total Arch Reconstruction for Type A Aortic Dissection

BACKGROUND

Cerebral malperfusion and carotid artery dissection in patients with acute type A aortic dissections (TAAD) carry high morbidity and mortality. There are limited data on outcomes of concomitant carotid artery replacement with total arch replacement in the setting of TAAD.

METHODS

All patients with acute TAAD who underwent a total arch replacement between 2007 and 2018 were included. Data were retrospectively collected from a prospectively maintained database. Baselines variables were compared, and Kaplan-Meier estimates were used for long-term survival. Cox multivariable regression analysis was used to identify predictors of mortality.

RESULTS

A total of 161 patients underwent total arch replacement for acute TAAD. Of these, 111 underwent conventional total arch reconstruction, and 50 had a concomitant carotid artery replacement. Baseline characteristics were similar between both cohorts apart from the carotid replacement cohort having a higher rate of preoperative cerebral malperfusion (48% vs 10.81%, P < .01) and preoperative stroke (28% vs 11.71%, P = .02). There was no difference in (operative) 30-day mortality between the carotid replacement and conventional total arch replacement groups (22% vs 18.9%, P = .81), 1-year mortality (28% vs 27.9%, P = .99), or 5-year mortality (32% vs 29.7%, P = .917). Postoperative stroke was 0% vs 4.5% (P = .301) for the carotid vs conventional total arch replacement cohort.

CONCLUSIONS

Concomitant carotid artery replacement is a feasible and safe technique to address perioperative cerebral malperfusion, carotid dissection, and neurologic dysfunction associated with carotid artery dissection, with no difference in long-term survival or postoperative stroke when compared with conventional total arch replacement.

Management of thrombosis of carotid arteries in acute type A aortic dissection in neurologically intact patients: our experience

The extension of aortic dissection into common carotid arteries can cause thrombus formation in false lumen. This may result in perioperative cerebral malperfusion and stroke. At present there are no specific management guidelines in this situation. We report our experience of operative and non-operative management of thrombosis of carotid arteries in type A acute aortic dissection in 3 patients.

Two Cases Treated by Different Strategies for Common Carotid Artery Dissection with Thrombosis Due to a Type A Aortic Dissection

Total arch replacement and stent trunk were performed for two patients. One of these underwent a total bilateral carotid artery replacement in anatomical position while the other underwent partial carotid artery dissection. The first patient demonstrated no neurological complication after surgery and a postoperative computed tomography angiography (CTA) showed bilateral common carotid artery patency. However, the second patient had neurological dysfunction after surgery, while a postoperative CTA showed occlusion of the left common carotid artery. Anatomical replacement for a common carotid artery dissection with thrombus has the potential to significantly improve cerebral perfusion and reduce postoperative neurological complications.

Mechanical Thrombectomy for Postoperative Stroke in a Patient with Acute Aortic Dissection Type A

Mechanical thrombectomy has been proposed to expand the treatment time window and enhance revascularization. However, it is unclear whether its use can be extended to patients with occlusions in acute aortic dissection, especially the thoracic aorta. A 55-year-old man underwent graft replacement for acute aortic dissection type A. On postoperative day 2, he developed stroke and computed tomography showed occlusion of the right middle cerebral artery. Mechanical thrombectomy was performed by transbrachial approach. Although successful recanalization was achieved, he suffered hemorrhagic stroke. Since there is no other effective treatment and the neurologic outcome with conservative management is poor, we consider mechanical thrombectomy to be a viable therapeutic option for the treatment of postoperative stroke in patients with acute aortic dissection type A. However, further study is warranted regarding the safety of this technique.

Utility of neuromonitoring in hypothermic circulatory arrest cases for early detection of stroke: Listening through the noise

OBJECTIVE

Stroke remains a potentially devastating complication of aortic arch intervention. The value of neurophysiologic intraoperative monitoring (NIOM) in the early identification of stroke is unclear. We evaluated the utility of NIOM for early stroke detection in aortic arch surgery.

METHODS

Across 8 years at our institution, 365 patients underwent aortic arch surgery with hypothermic circulatory arrest, and 224 cases utilized NIOM. One patient was excluded for intraoperative death. In the remaining cohort, we reviewed the incidence, timing, and location of strokes, and the incidence and nature of NIOM alerts.

RESULTS

Hemiarch was performed in 154 patients and total arch replacement in 69 patients. Stroke occurred in 6.3% of all cases (14 out of 223), 15.9% of total arches (11 out of 69), and 2.0% of hemiarches (3 out of 154). There were 33 NIOM alerts (14.8%), and 9 patients had both alerts and stroke. Of these, NIOM deficits plausibly correlated with imaging findings in 7 cases (78%). Of the 5 stroke patients without NIOM alerts, 2 developed neurologic symptoms 3 days or more postoperatively, and infarcts in 3 patients did not result in sensory or motor deficits. Excluding 2 patients with late stroke, the sensitivity of NIOM for stroke detection was 75%, specificity was 88.5%, positive predictive value was 27.3%, and negative predictive value was 97.4%.

CONCLUSIONS

Despite a low positive predictive value requiring a high level of discrimination when interpreting abnormal findings, NIOM has high sensitivity and specificity for the early stroke detection. Furthermore, its high negative predictive valve is reassuring for low risk of stroke in the absence of alerts.

Left Subclavian-Bilateral External Carotid Artery Bypass for Symptomatic Carotid Artery Dissection Secondary to Open Repair of Type A Aortic Dissection

Symptomatic carotid dissection, secondary to surgical repair of Stanford type A acute aortic dissection (AAD), requires prompt intervention. A 56-year-old man who underwent total arch replacement with frozen elephant trunk for AAD presented with left hemiplegia and unilateral spatial neglect 16 h after the surgery. Cerebral computed tomography (CT) revealed no fresh lesions, and CT angiography showed severe bilateral carotid dissection. The patient’s neurological symptoms improved soon after left subclavian-bilateral external carotid artery bypass to correct symptomatic severe right cerebral ischemia. Therefore, this technique can be a good option for symptomatic carotid dissection in selected patients.

Dissection of Arch Branches Alone: An Indication for Aggressive Arch Management in Type A Dissection?

BACKGROUND

It is controversial if extension of aortic dissection into arch branches should be an indication for replacement of the arch and its branches in acute type A aortic dissection.

METHODS

From 2008 to April 2018, 399 patients underwent open repair for an acute type A aortic dissection, and 190 patients had known innominate and/or left common carotid artery dissection without malperfusion syndrome, including no arch procedure (n = 1)/hemiarch replacement (n = 109) and zone 1/2/3 arch replacement (n = 80) with replacement of 1 to 4 arch branch vessels.

RESULTS

Median patient age was 58 years. Preoperative comorbidities were similar between groups, except the hemiarch group had more coronary artery disease (22% vs 3%, P = .0002). Both groups underwent similar aortic root procedures and other concomitant procedures with equivalent cardiopulmonary bypass and aortic cross-clamp times. The zone 1/2/3 group had longer hypothermic circulatory arrest times with greater use of antegrade cerebral perfusion (all P < .05). The perioperative and midterm outcomes were similar between the hemiarch and zone 1/2/3 arch groups, including 30-day mortality (7% vs 5%), rates of transient ischemic attack and stroke, incidence rates of reoperation for distal aortic pathology with a mean follow-up time of 3.5 years, and 5-year survival (79% [95% confidence interval, 69%-87%] vs 85% [95% confidence interval, 71%-93%]). However the hemiarch group had a trend of increased cumulative incidence of reoperation (8-year, 23% vs 9%; P = .33).

CONCLUSIONS

In acute type A aortic dissection, dissection of arch branches alone should not be an indication for routine zone 1/2/3 arch replacement; however zone 1/2/3 arch replacement could be considered to prevent future reoperations in select patients.

Ultrasonographic detection of chronic type A aortic dissection extending to the right extracranial internal carotid artery: A case report

We report the case of a patient with chronic type A aortic dissection (AD), who had been admitted, 18 months ago, to another hospital with acute chest-tearing pain accompanied with transient loss of consciousness. His symptoms resolved but he reported after discharge a toothache and fluctuating right mandibular pain. He presented to our outpatient clinic because his facial pain aggravated. Physical examination demonstrated a bruit over the right carotid artery. Transthoracic echocardiography and carotid sonography demonstrated aortic dissection extending into the extracranial right internal carotid artery (ICA), which was tortuous. The patient refused surgery. This case reminds us that AD can involve the extracranial ICA, and that long-term survival is possible with type A acute AD without treatment. Carotid ultrasonography is noninvasive, inexpensive, easily performed, and can lead to the detection of chronic type A AD extending to the extracranial ICA.

Open brachiocephalic artery stent for static obstruction caused by acute type A aortic dissection

Brachiocephalic artery dissection complicated by acute type A aortic dissection occasionally causes cerebral malperfusion. Although immediate central aortic repair has been the standard treatment for aortic dissection, dissection in supra-aortic vessels frequently remains after the surgery. The residual brachiocephalic artery dissection is reported to be associated with late neurological events. Therefore, additional intervention for brachiocephalic artery dissection during central aortic repair should be considered in selected cases. In this report, we describe two cases requiring open brachiocephalic artery stenting simultaneous with central aortic repair. There were no neurological or stent induced complications at latest follow-up.

Initial clinical impact of inhaled nitric oxide therapy for refractory hypoxemia following type A acute aortic dissection surgery

BACKGROUND

To evaluate the effect of inhaled nitric oxide (iNO) therapy on oxygenation and clinical outcomes in patients with refractory hypoxemia after surgical reconstruction for acute type A aortic dissection (TAAD).

METHODS

A before-and-after interventional study was conducted in patients with refractory hypoxemia after surgical reconstruction for TAAD. Postoperative refractory hypoxemia was defined as a persistent PaO₂/FiO₂ ratio ≤100 mmHg despite conventional therapy. From January to November 2016, conventional treatment was carried out for refractory hypoxemia. From December 2016 to October 2017, on the basis of conventional therapy, we explored the use of iNO to treat refractory hypoxemia.

RESULTS

Fifty-three TAAD patients with refractory hypoxemia were enrolled in this study. Twenty-seven patients received conventional treatment (conventional group), while the remaining 26 patients received iNO therapy. The PaO₂/FiO₂ ratio was significantly higher in the iNO group after treatment than in the conventional group when analyzed over the entire 72 hours. The duration of invasive mechanical ventilation was significantly reduced in the iNO group (69.19 vs. 104.56 hours; P=0.003). Other outcomes, such as mortality (3.85% vs. 7.41%, P=1.000), intensive care unit (ICU) duration (9.88 vs. 12.36 days, P=0.059) and hospital stay (16.88 vs. 20.76 days, P=0.060), were not significantly different between the two groups.

CONCLUSIONS

iNO therapy might play an ameliorative role in patients with refractory hypoxemia after surgical reconstruction for TAAD. This therapy may lead to sustained improvement in oxygenation and reduce the duration of invasive mechanical ventilation.

Cerebrovascular imaging of cerebral ischemia in acute type A aortic dissection

BACKGROUND AND PURPOSE

Stanford type A aortic dissection (AAD) sometimes causes acute ischemic stroke (AIS) or transient ischemic attack (TIA). There is little understanding of cerebrovascular imaging of AIS or TIA in patients with AAD.

METHODS

Consecutive AIS/TIA patients with AAD who were admitted within 4.5 h of onset were reviewed. We compared findings of MRI/MRA between these and consecutive AIS/TIA patients without AAD within 4.5 h of onset.

RESULTS

Seventeen AAD and 249 non-AAD patients were identified. Compared to non-AAD patients, AAD patients had infarcts more frequently in the right anterior cerebral artery (ACA) territory (18% vs. 2%, P = 0.007) and the right middle cerebral artery (MCA) territory (71% vs. 29%, P < 0.001). There was no difference between the groups regarding whether it was perforator or cortical infarct, single or multiple infarcts, unilateral or bilateral infarcts, or ischemic change extension. On the MRA imaging, the AAD patients more frequently had poor visualization of the right internal carotid artery (ICA) (47% vs. 6%, P < 0.001). After adjustment for sex, age and confounding factors, the right ACA territory infarct [odds ratio (OR), 12.2; 95% confidence interval (CI), 1.4-119.4], the MCA territory infarct (OR, 4.9; 95% CI, 1.0-25.0) and poor visualization of the right ICA (OR, 18.1; 95% CI, 4.0-101.9) were independently associated with AAD.

CONCLUSION

In emergency AIS/TIA patients, right anterior circulation infarct and poor visualization of the right ICA on cerebrovascular imaging are potential imaging markers of AAD.

Risk of Mortality After Resolution of Spinal Malperfusion in Acute Dissection

BACKGROUND

Spinal cord ischemia (SCI) may develop in patients presenting with acute aortic dissection. We sought to determine how SCI and its recovery affect outcomes.

METHODS

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.

RESULTS

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).

CONCLUSIONS

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.

Management and outcomes of carotid artery extension of aortic dissections

BACKGROUND

Aortic dissection (AD) is the most common aortic catastrophe. Carotid artery dissection due to extension of AD (CAEAD) is one severe complication of this condition. Despite years of refinement in the techniques for repair of AD, the optimal management strategy for CAEAD remains yet to be described. We hypothesized that CAEAD eventually resolves on antiplatelet therapy with a low but not insignificant risk of cerebrovascular accident (CVA).

METHODS

This was a single-institution retrospective review of patients admitted with nontraumatic coincident aortic and carotid dissection between 2001 and 2013.

RESULTS

CAEAD was present in 38 patients (24 men [53%]). The median age was 59.5 years (range, 25-85 years). A Stanford type A AD was diagnosed in 36 patients (95%). CVA or transient ischemic attack was identified in 11 patients (29%). Eight were potentially attributable to the carotid lesion. Two of these eight strokes resulted in death. Of the 11 CVAs and transient ischemic attacks, 8 were evident at presentation, 2 were diagnosed postoperatively during hospitalization, and 1 was diagnosed during early follow-up. Only one of these three postadmission strokes was attributable to the carotid lesion. Nonoperative management of aortic and carotid dissections was pursued in 9 patients (24%), 26 (68%) underwent open repair, and 4 (11%) had endovascular management of AD (2 thoracic endovascular aortic repair, 2 endovascular fenestrations), including 1 patient with a staged hybrid procedure (frozen elephant trunk). There were eight inpatient deaths (21%) and nine deaths in the follow-up period. Of the 30 patients who survived to discharge, 24 (80%) were managed with antiplatelet therapy. At a median follow-up of 14.5 months in 22 patients with follow-up computed tomography scans available, a minority of lesions had resolved, and only one CVA was reported.

CONCLUSIONS

This study found that CAEAD was associated almost exclusively with type A AD, was typically unilateral, most often on the left, and usually persisted at follow-up. Many CAEAD patients presented with CVA and experienced significant early mortality. Notably, not all CVA events were attributable to the CAEAD. CVAs were not common after admission, and there appeared to be a low risk of new or subsequent stroke during follow-up with routine antiplatelet and antihypertensive therapy.

Independent risk factors for hypoxemia after surgery for acute aortic dissection

Objectives:

To determine risk factors associated with postoperative hypoxemia after surgery for acute type A aortic dissection.

Methods:

We retrospectively analyzed the clinical data of 192 patients with acute type A aortic dissection who underwent surgery in Qingdao Municipal Hospital, Medical College of Qingdao University, Qingdao, China between January 2007 and December 2013. Patients were divided into hypoxemia group (n=55) [arterial partial pressure of oxygen (PaO₂)/fraction of inspired oxygen (FiO₂) ≤200 mm Hg] and non-hypoxemia group (n=137) [PaO₂/FiO₂ >200 mm Hg]. Perioperative clinical data were analyzed and compared between the 2 groups.

Results:

The incidence of postoperative hypoxemia after surgery for acute aortic dissection was 28.6% (55/192). Perioperative death occurred in 13 patients (6.8%). Multivariate regression identified body mass index (BMI) >25 kg/m² (OR=21.929, p=0.000), deep hypothermic circulatory arrest (DHCA) (OR=11.551, p=0.000), preoperative PaO₂/FiO₂ ≤300 mm Hg (OR=7.830, p=0.000) and blood transfusion >6U in 24 hours postoperatively (OR=12.037, p=0.000) as independent predictors of postoperative hypoxemia for patients undergoing Stanford A aortic dissection surgery.

Conclusion:

Our study demonstrated that BMI >25 kg/m², DHCA, preoperative PaO₂/FiO₂ ≤300 mm Hg, and blood transfusion in 24 hours postoperatively >6U were independent risk factors of the hypoxemia after acute type A aortic dissection aneurysm surgery.

The cannulation strategy in surgery for acute type A dissection

The rates of mortality and morbidity remain high in surgery for acute type A dissection. There is controversy regarding the best cannulation strategy for achieving good clinical results. Each cannulation technique has different anatomical characteristics and a different flow pattern inside the aorta during cardiopulmonary bypass. Some adverse, clinically important outcomes may be related to events at this time. Femoral artery cannulation, axillary artery cannulation, and central aortic cannulation are the three major cannulation strategies that are adopted in many centers in the world. Accumulating results from comparative studies between right axillary artery cannulation and femoral artery cannulation show that right axillary artery cannulation is associated with better clinical outcomes. However, all of the studies have been retrospective, and few studies have compared the results of other combinations of cannulation strategies. Observational studies using newer monitoring techniques clearly show that no perfusion strategy is perfect or free from complications. In summary, the evidence is insufficient to make a strong recommendation regarding cannulation strategies. Based on the fairly consistent results of retrospective studies, more surgeons are tending to switch from a retrograde perfusion strategy to adopt an antegrade perfusion strategy. Regardless of the routine cannulation strategy that is adopted, careful monitoring and a swift response to adverse events are necessary. The further accumulation of evidence is warranted.

Differential outcomes of type A dissection with malperfusion according to affected organ system

BACKGROUND

The management of malperfusion in patients with acute Stanford type A aortic dissection is controversial. We sought to determine the rate of resolution of malperfusion following primary repair of the dissection and to identify anatomic sites of malperfusion that may require additional management.

METHODS

We reviewed the hospital records of patients who presented to our institution with acute type A aortic dissection. Patient demographics, operative details and post-operative course were retrospectively extracted from our institutional electronic database. Depending upon the anatomic site, malperfusion was identified by a combination of radiographic and clinical definitions. Data were analyzed using standard univariable and multivariable methods.

RESULTS

Between 1997-2013, 101 patients underwent repair of an acute type A dissection. Thirty-day mortality was 14.9% (15/101); there were five intraoperative deaths. There was no difference in 30-day mortality between patients with or without malperfusion (15.4% vs. 14.7%, P=0.93). Twenty-five patients (24.7%), who survived surgery, presented with 31 sites of malperfusion. Anatomic sites included extremities [14], renal [10], cerebral [5] and intestinal [2]. Of these 31 sites, malperfusion resolved in 18 (58.1%) with primary aortic repair. Renal malperfusion resolved radiographically in 80.0%, with no difference in the incidence of insufficiency (44.0% vs. 35.2%; P=0.44) or dialysis (20.0% vs. 15.5%; P=0.61) between malperfusion and non-malperfusion patients. Extremity malperfusion resolved postoperatively in six out of 14 patients. Of the remaining eight, concomitant revascularization was performed in four, one had an amputation and three required postoperative interventions. Advanced patient age (OR: 1.06, 95% CI: 1.01-1.12, P=0.02) was an independent predictor of 30-day mortality, while preoperative malperfusion was not (OR: 0.77, 95% CI: 0.18-3.31, P=0.73).

CONCLUSIONS

Malperfusion complicating acute type A dissection can be managed in many patients by aortic replacement alone with low overall mortality. Most cases of renal and cerebral malperfusion resolved following aortic surgery. Revascularization was frequently necessary in patients with extremity malperfusion. Patients presenting with intestinal ischemia had very poor outcomes. A patient-specific approach is recommended in such complex patients.