The Use of the Ascyrus Medical Dissection Stent in Acute Type A Aortic Dissection Repair Reduces Distal Anastomotic New Entry Tear

BACKGROUND

A distal anastomotic new entry tear (DANE) can occur at the time of surgical repair for acute type A aortic dissection (ATAAD). This study aimed to compare the occurrence of DANE following a standard hemiarch repair with that following a hemiarch repair with an uncovered arch dissection stent.

METHODS

All patients who received a hemiarch repair or a hemiarch repair with an Ascyrus Medical Dissection Stent (AMDS) for ATAAD from 2017 to 2021 were included. Baseline and intra- and postoperative characteristics were collected. All available pre- and postoperative computed tomographic scans were analysed. The primary outcome measures were the incidence of DANE, positive aortic remodelling, mortality, and aortic reintervention rates at last follow-up.

RESULTS

A total of 114 patients underwent repair of Debakey I ATAAD during the study period with either an isolated hemiarch (n = 77) or a hemiarch with AMDS (n = 37). There was no significant difference in mortality (P = 0.768) or other in-hospital adverse events. During the follow-up period, DANE occurred in 43.3% (n = 26) of the isolated hemiarch group and in 11.8% (n = 4) of the hemiarch with AMDS group (P = 0.002). The incidence of false lumen thrombosis and obliteration favoured the AMDS group in the aortic arch (P = 0.029), the proximal descending thoracic aorta (P = 0.031), and level of pulmonary artery bifurcation (P = 0.044).

CONCLUSIONS

The incidence of DANE is significantly reduced with the addition of an AMDS at the time of hemiarch repair for ATAAD repair. Further follow-up is necessary to identify late aortic complications that may have been prevented by reducing the incidence of postoperative DANE.

Surgical outcomes associated with sleep apnea syndrome in Stanford A aortic dissection patients

Background

Patients suffering from aortic dissection (AD) often experience sleep apnea syndrome (SAS), which aggravates their respiratory function and aortic false lumen expansion.

Methods

We analyzed the peri-operative data of Stanford A AD patients, with or without SAS, between January 2017 and June 2019. Subjects were separated into SAS positive (SAS⁺) and SAS negative (SAS⁻) cohorts, based on the Apnea-Hypopnea Index (AHI) and the Oxygen Desaturation Index (ODI). We next analyzed variables between the SAS⁺ and SAS⁻ groups.

Results

155, out of 198 AAD patients, were enlisted for this study. SAS⁺ patients exhibited higher rates of pneumonia (p < 0.001), heart failure (HF, p = 0.038), acute kidney injury (AKI, p = 0.001), ventilation time (p = 0.009), and hospitalization duration (p < 0.001). According to subsequent follow-ups, the unstented aorta false lumen dilatation (FLD) rate increased markedly, with increasing degree of SAS (p < 0.001, according to AHI and ODI). The SAS⁺ patients exhibited worse cumulative survival rate (p = 0.025). The significant risk factors (RF) for poor survival were: severe (p = 0.002) or moderate SAS (p = 0.008), prolonged ventilation time (p = 0.018), AKI (p = 0.015), HF New York Heart Association (NYHA) IV (p = 0.005) or III (p = 0.015), pneumonia (p = 0.005), Marfan syndrome (p = 0.010), systolic blood pressure (BP) upon arrival (p = 0.009), and BMI ≥ 30 (p = 0.004).

Conclusions

SAS⁺ Stanford A AD patients primarily exhibited higher rates of complications and low survival rates in the mid-time follow-up. Hence, the RFs associated with poor survival must be monitored carefully in SAS patients. Moreover, the FLD rate is related to the degree of SAS, thus treating SAS may mitigate FLD.

False Lumen Flow Assessment by Magnetic Resonance Imaging and Long-Term Outcomes in Uncomplicated Aortic Dissection

BACKGROUND

Despite the absence of clinical complications after an acute aortic dissection (AD) with persistent patent false lumen (FL), a high risk for clinical events may persist.

OBJECTIVES

The aim of this study was to assess the natural evolution of noncomplicated AD and ascertain whether different FL flow patterns by magnetic resonance imaging (MRI) have independent prognostic value for AD-related events beyond established morphologic parameters.

METHODS

One hundred thirty-one consecutive patients, 78 with surgically treated type A dissections and 53 with medically treated type B dissections, were followed up prospectively after acute AD with persistent patent FL in the descending aorta. Maximum aortic diameter, true lumen compression, entry tear, and partial FL thrombosis by computed tomography were assessed. Systolic antegrade true lumen and FL flow volumes and diastolic antegrade and retrograde flows were analyzed by MRI during the first year after AD.

RESULTS

After a median follow-up period of 8.0 years (IQR: 4.6-10.9 years), 43 patients presented aorta-related events (25 died and 18 required endovascular treatment). FL systolic antegrade flow ≥30% with respect to total systolic antegrade flow and retrograde diastolic flow ≥80% with respect to total diastolic FL flow were predictors of aortic events. In multivariate analysis, aortic diameter >45 mm (HR: 2.91), type B dissection (HR: 2.44), and MRI flow pattern (HR: 16.87) were independent predictors of AD-related events.

CONCLUSIONS

High systolic antegrade flow volume in the FL with significant diastolic retrograde flow assessed by MRI and aortic diameter >45 mm identify patients with higher risk for complications in whom more aggressive management would be indicated.

Role of proximal and distal tear size ratio in hemodynamic change of acute type A aortic dissection

Background

Acute type A aortic dissection (ATAAD) is a life-threatening disease. The aim of this study was to examine the role of tear size in the hemodynamic change and help improve the treatment level of this extremely dangerous disease.

Methods

A total of 120 ATAAD patients treated in our institution from November 2014 to December 2016 were divided into three groups according to proximal and distal tear size ratio (PDTSR). There were 35 patients in group A (PDTSR ≥2:1), 44 patients in group B (1:2< PDTSR <2:1), and 41 patients in Group C (PDTSR ≤1:2). Three computational fluid dynamics (CFD) models with different PDTSRs were established to investigate the hemodynamic difference in the three groups.

Results

The mean age (± SD) of the 120 patients included in this study was 47.7±10.1 years. Patients in Group A had a significantly larger proximal tear size (219.1±76.5 vs. 127.7±70.1 vs. 75.7±49.7 mm²; P<0.001). The mortality of the patients in group A was significantly higher than those in group B and group C in the acute phase (37.1% vs. 2.3% vs. 2.4%, respectively; P<0.001). A proximal tear larger than a distal tear was found to be significantly associated with preoperative death in logistic regression analysis (odds ratio: 15.89; 95% confidence interval, 2.702-93.477; P=0.002).

Conclusions

A proximal tear larger than a distal tear was associated with a significantly high-pressure difference between false and true lumens and more blood flow into the false lumen. In such cases, patients would experience extremely high mortality and morbidity.

Repair of Acute Type-A Aortic Dissection in the Present Era: Outcomes and Controversies

Acute Type-A aortic dissection (AAAD) remains a surgical emergency with a relatively high operative mortality despite advances in medical and surgical management over the past three decades. In spite of the severity of disease, there is a paucity of studies reviewing key controversies surrounding AAAD repair and management. A systematic literature search was performed using Cochrane review and PubMed bibliography review. Abstracts were first reviewed for general pertinence and then articles were reviewed in full. Literature review indicates that use of moderate hypothermia and antegrade cerebral perfusion is a safe alternative to deep hypothermia. In hemodynamically stable patients, axillary cannulation may be substituted for femoral cannulation. With regard to the technical aspects of repair, preserving the aortic root whenever possible and performing the distal anastomosis with the open distal technique rather than with the clamp on is the preferred approach. In patients with a patent false lumen, close monitoring is indicated. As demonstrated by the literature, significant improvement of early and late mortality over the past years has occurred in patients presenting with AAAD. Repair of acute Type-A aortic dissection remains a challenge with high operative mortality; however, improvement of surgical techniques and management have resulted in improvement of early and late clinical outcomes.

Aortic morphology post type A acute aortic syndrome: Prognosis significance and association with 24-hour blood pressure-monitoring parameters

BACKGROUND

After an emergent surgery for type A acute aortic syndrome, medical management is based on optimal blood pressure (BP) control. We assessed the prognostic significance of BP monitoring and its relationship with aortic morphology following type A acute aortic syndrome.

METHODS

The data of 120 patients who underwent BP monitoring after a type A acute aortic syndrome from January 2005 to June 2016 were retrospectively collected. The first CT angiogram performed after surgery was used for the morphological analysis.

RESULTS

The population included 79 males, with an overall mean age of 60 ± 12 years. Seven patients (5.8%) died during a median follow-up of 5.5 years. The median delay between BP monitoring and discharge was 3 (1-5) months. The mean 24-hour BP of the cohort was 127/73 mm Hg ± 10/17. During follow-up, different parameters of BP monitoring were not associated with the risk of aortic events. However, the diameter of the false lumen of the descending thoracic aorta was the best predictor associated with the risk of new aortic events during follow-up, particularly for the threshold of 28 mm or more (P < .001; Hazard ratio 4.7[2.7-8.2]). The diameter of the false lumen was associated with night-time systolic BP (P = .025; r = .2), 24-hour pulse pressure (P = .002; r = .28), and night-time pulse pressure (P = .008; r = .24).

CONCLUSION

The risk of new aortic events following type A acute aortic syndrome is associated with the size of the residual false lumen, but not directly with BP parameters. Night-time BP parameters are associated with the size of the residual false lumen.

The prognostic impact of distal anastomotic new entry after acute type I aortic dissection repair

OBJECTIVES

Distal anastomotic new entry (DANE) is considered to be one of the causes of patent false lumen (PFL) after acute type I aortic dissection repair. However, there have been few articles with regard to this important issue. We assessed the influence of PFL caused by DANE on long-term outcomes.

METHODS

One hundred twenty-two patients underwent emergency surgery for acute type I aortic dissection (2007-12). The in-hospital mortality was 8% (10 patients). Among the survivors, 93 patients (mean age 67 years) underwent enhanced computed tomography within 2 weeks after the operation. These patients were divided into 3 groups according to the status of the residual FL: those with a PFL with DANE (n = 19) or without DANE (n = 27) and those with a thrombosed FL (n = 47). Changes in descending aortic diameter were analysed between early and last follow-up images.

RESULTS

Aortic growth rate in the PFL with DANE group was greater than that of the other 2 groups (P < 0.05). The PFL with DANE group demonstrated a lower rate of freedom from dissection-related event of distal aorta (66% at 5 years) and enlargement of distal aortic lesions (62% at 5 years). There were no significant differences in late survival among the groups. PFL with DANE was one of the significant risk factors for distal aortic events.

CONCLUSIONS

PFL caused by DANE after acute type I aortic dissection repair showed greater aortic growth rate of the descending aorta and was one of the significant risk factors for distal aortic events.