Management of Type B Aortic Dissections: Treatment of Acute Dissections and Acute Complications from Chronic Dissections

Establishing and Validating a Morphological Prediction Model Based on CTA to Evaluate the Incidence of Type-B Dissection

Background: Many patients with Type B aortic dissection (TBAD) may not show noticeable symptoms until they become intervention and help prevent critically ill, which can result in fatal outcomes. Thus, it is crucial to screen people at high risk of TBAD and initiate the necessary preventive and therapeutic measures before irreversible harm occurs. By developing a prediction model for aortic arch morphology, it is possible to accurately identify those at high risk and take prompt action to prevent the adverse consequences of TBAD. This approach can facilitate timely the development of serious illnesses. Method: The predictive model was established in a primary population consisting of 173 patients diagnosed with acute Stanford TBAD, with data collected from January 2017 and December 2018, as well as 534 patients with healthy aortas, with data collected from April 2018 and December 2018. Explicitly, the data were randomly separated into the derivation set and validation set in a 7:3 ratio. Geometric and anatomical features were extracted from a three-dimensional multiplanar reconstruction of the aortic arch. The LASSO regression model was utilized to minimize the data dimension and choose relevant features. Multivariable logistic regression analysis and backward stepwise selection were employed for predictive model generation, combining demographic and clinical features as well as geometric and anatomical features. The predictive model's performance was evaluated by examining its calibration, discrimination, and clinical benefit. Finally, we also conducted internal verification. Results: After applying LASSO logistic regression and backward stepwise selection, 12 features were entered into the prediction model. Age, aortic arch angle, total thoracic aorta distance, ascending aorta tortuosity, aortic arch tortuosity, distal descending aorta tortuosity, and type III arch were protective factors, while male sex, hypertension, aortic arch height, and aortic arch distance were risk factors. The model exhibited satisfactory discrimination (AUC, 0.917 [95% CI, 0.890-0.945]) and good calibration in the derivation set. Applying the predictive model to the validation set also provided satisfactory discrimination (AUC, 0.909 [95% CI, 0.864-0.953]) and good calibration. The TBAD nomogram for clinical use was established. Conclusions: This study demonstrates that a multivariable logistic regression model can be used to predict TBAD patients.

Potential biomarkers of aortic dissection based on expression network analysis

Background

Aortic dissection (AD) is a rare disease with severe morbidity and high mortality. Presently, the pathogenesis of aortic dissection is still not completely clear, and studying its pathogenesis will have important clinical significance.

Methods

We downloaded 28 samples from the Gene Expression Omnibus (GEO) database (Accession numbers: GSE147026 and GSE190635), including 14 aortic dissection samples and 14 healthy controls (HC) samples. The Limma package was used to screen differentially expressed genes. The StarBasev2.0 tool was used to predict the upstream molecular circRNA of the selected miRNAs, and Cytoscape software was used to process the obtained data. STRING database was used to analyze the interacting protein pairs of differentially expressed genes under medium filtration conditions. The R package "org.hs.eg.db" was used for functional enrichment analysis.

Results

Two hundred genes associated with aortic dissection were screened. Functional enrichment analysis was performed based on these 200 genes. At the same time, 2720 paired miRNAs were predicted based on these 200 genes, among which hsa-miR-650, hsa-miR-625-5p, hsa-miR-491-5p and hsa-miR-760 paired mRNAs were the most. Based on these four miRNAs, 7106 pairs of circRNAs were predicted to be paired with them. The genes most related to these four miRNAs were screened from 200 differentially expressed genes (CDH2, AKT1, WNT5A, ADRB2, GNAI1, GNAI2, HGF, MCAM, DKK2, ISL1).

Conclusions

The study demonstrates that miRNA-associated circRNA-mRNA networks are altered in AD, implying that miRNA may play a crucial role in regulating the onset and progression of AD. It may become a potential biomarker for the diagnosis and treatment of AD.

Preoperative clinical application of human fibrinogen in patients with acute Stanford type A aortic dissection: A single-center retrospective study

OBJECTIVE

To evaluate the perioperative clinical efficacy of preoperative human fibrinogen treatment in patients with acute Stanford type A aortic dissection (ATAAD).

METHODS

Data of 159 patients with ATAAD who underwent emergency surgical treatment in our hospital from January 2019 to December 2020 were retrospectively analyzed. Patients were divided into two groups according to whether human fibrinogen was administered before surgery: patients in group A received fibrinogen before surgery, while those in group B did not. The preoperative clinical data, surgical data, postoperative data, complications related to the coagulation function, and mortality of the two groups were compared and analyzed.

RESULTS

The in-hospital mortality was similar in the two groups (2.9% vs. 9.3%, p = .122). However, group A had a significantly shorter operation time (279.24 ± 39.03 vs. 298.24 ± 45.90, p = .008), lower intraoperative blood loss (240.48 ± 96.75 vs. 353.70 ± 189.80, p < .001), and reduced intraoperative transfusion requirement of red blood cells (2.61 ± 1.18 vs. 6.05 ± 1.86, p < .001). The postoperative suction drainage within 24 h in group A was significantly decreased (243.24 ± 201.52 vs. 504.22 ± 341.08, p = .002). The incidence of postoperative acute kidney injury (AKI) in group A was lower than that in group B (3.8% vs. 14.8%, p = .023). Similarly, the incidence of postoperative hepatic insufficiency in group A was lower than that in group B (1.9% vs. 9.3%, p = .045). In group A, the mechanical ventilation time was shorter (47.68 ± 28.61 vs. 118.21 ± 173.16, p = .004) along with reduced intensive care unit stay time (4.06 ± 1.18 vs. 8.09 ± 9.42, p = .003), and postoperative hospitalization days (19.20 ± 14.60 vs. 23.50 ± 7.56, p = .004).

CONCLUSION

Preoperative administration of human fibrinogen in patients undergoing ATAAD surgery can effectively reduce the intraoperative blood loss, amount of blood transfused, operation time, and postoperative complications, and improve the early prognosis of patients. In addition, this procedure is highly safe.

Management of Acute, Complicated Type B Aortic Dissection

Management of acute complicated Type B aortic dissection (TBAD) requires a multidisciplinary approach with careful evaluation and understanding of the complicating features. Patients who present with or progress to a complicated TBAD must be triaged and managed rapidly due to the high morbidity and mortality even in the presence of optimal medical, endovascular, and open therapies. When required, invasive therapies can be broken down most simply into four treatments: thoracic endograft placement, aortic fenestration, branch vessel stenting, and open repair. However, which therapy to offer and in which order is often unclear. In this review, focus is placed on clinical presentation, diagnosis, and explanation for one or a combination of these therapies. In addition, contraindications as well as expected outcomes, complications, and adjunct therapies will be reviewed. The advent of advanced endovascular techniques has certainly improved the immediate morbidity and mortality of acute complicated TBAD; however, much remains to learn about patient selection and therapeutic intervention performed.

Type B Aortic Dissection Complicated by Intimo-Intimal Intussusception and Extensive Intimal Denuding: Case Report with Long-term Follow-up

BACKGROUND

Acute aortic dissection rarely results in circumferential dissections of the aortic intima that may lead to intimo-intimal intussusception (IIS) with complete separation from the aortic wall. Circumferential dissection may then result in distal embolization of the involved intima and media, adding considerable complexity to the management of such cases. Despite the severity of this complication, the natural history of aortic disease following extensive intimal denuding and IIS is not well documented in the literature. Here we present a case with long-term follow-up of type B aortic dissection (TBAD) complicated by IIS and embolization of the intima into the distal aorta following thoracic endovascular aortic repair.

METHODS

Medical records and imaging studies were retrospectively reviewed with the approval of the Institutional Review Board. A single patient underwent repair of a TBAD that was complicated by IIS, with follow-up for 6 years. Aortic recovery was monitored with serial computerized tomography scans.

RESULTS

During endovascular stent deployment, the patient's dissection progressed circumferentially, leading to distal embolization of the intima and aortic occlusion. An open transabdominal aortic exploration was performed to extract the embolized intima. Despite this severe aortic structural disruption, the patient recovered well postoperatively and exhibited favorable aortic remodeling over long-term follow-up. The denuded aorta did not rupture or develop progressive worsening aneurysmal dilation and the diameter of the involved aortic segment remained stable during follow-up.

CONCLUSIONS

Acute TBADs can progress to circumferential intimal separation and IIS when managed with endovascular stenting and balloon dilation. Continued endovascular management once IIS has occurred may lead to further intimal damage, resulting in distal embolization of the intima and aortic occlusion. Thus, IIS may require conversion to open repair. However, in the event that loss of the aortic intima does occur following IIS, it is possible for the denuded aorta to recover well and remain stable with favorable remodeling over long-term follow-up.

Top 10 candidate aortic disease trials

Aortic pathologies such as aneurysm, dissection and trauma are relatively common and potentially fatal diseases. Over the past two decades, we have experienced unprecedented technical and medical developments in the field. Despite this, there is a great need, and great opportunities, to further explore the area. In this review, we have identified important areas that need to be further studied and selected priority aortic disease trials. There is a pressing need to update the AAA natural history and the role for endovascular AAA repair as well as to define biomarkers and genetic risk factors as well as influence of gender for development and progression of aortic disease. A key limitation of contemporary treatment strategies of AAA is the lack of therapy directed at small AAA, to prevent AAA expansion and need for surgical repair, as well as to reduce the risk for aortic rupture. Currently, the most promising potential drug candidate to slow AAA growth is metformin, and RCTs to verify or reject this hypothesis are warranted. In addition, the role of endovascular treatment for ascending pathologies and for uncomplicated type B aortic dissection needs to be clarified.

Thoracic endovascular aneurysm repair to treat recurrent lower limb ischemia secondary to occlusion of axillofemoral bypass

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One of the complications of type B aortic dissection is organ ischemia.

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TEVAR was performed for entry closure.

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TEVAR improved malperfusion.

Introduction

A case of malperfusion in which the patient presented with aortic dissection is presented.

Presentation of case

A 69-year-old man with an acute aortic dissection (Stanford type B) had lower limb ischemia. Axillary-femoral bypass was performed, and his lower limb ischemia improved. Eight months after the onset of acute aortic dissection, he again had lower limb ischemia. Contrast-enhanced computed tomography showed axillary-femoral bypass occlusion and true lumen collapse, compressed by the increased false lumen pressure in the aorta. Thoracic endovascular aortic repair (TEVAR) was performed for entry closure. His lower limb ischemia was improved by TEVAR.

Discussion

One of the complications of type B aortic dissection is malperfusion. Endovascular therapy is a first step in treating the malperfusion of type B aortic dissection. It is important to seal the entry for the treatment of malperfusion.

Conclusion

If there is an entry, it is important to seal it for the treatment of malperfusion.

Left ventricular assist device implant and subsequent orthotopic heart transplant after chronic type B aortic dissection

The criteria for being placed on the list of the International Society for Heart and Lung Transplantation for an orthotopic heart transplant mention nothing about patients with aortic dissection. Nor are there any guidelines pertaining to the patient with type B aortic dissection. Herein, we report the case of a patient with chronic type B aortic dissection for whom we successfully performed a left ventricular assist device implant followed by an orthotopic heart transplant.

Volume-Outcome Relationships in Surgical and Endovascular Repair of Aortic Dissection

BACKGROUND

As surgical mortality decreases and endovascular utilization increases, it is unknown whether volume-outcome relationships exist in thoracic aortic dissection repair. We characterized volume-outcome relationships for surgical and endovascular management of thoracic aortic dissection.

METHODS

Patients aged more than 18 years undergoing repair of thoracic aortic dissection in the United States between 2010 and 2014 were identified in seven all-payer state inpatient administrative databases. Patients were divided into groups based on type of repair: surgical repair of type A dissection (TAAD), surgical repair of type B dissection (TBAD), and endovascular repair (TEVAR). Hierarchical logistic regression models evaluated the association between hospital volume and in-hospital mortality.

RESULTS

Overall in-hospital mortality rate was 13.4% (890 of 6650), highest after TAAD (463 of 2918, 15.9%), followed by TBAD (270 of 1934, 14.0%) and TEVAR (157 of 1798, 8.7%). Volume-outcome relationships for adjusted in-hospital mortality were demonstrated for TAAD and TBAD (P-trend < .001), but not TEVAR (P-trend = .11). Adjusted in-hospital mortality differed most for TAAD (fewer than 3 cases per year: 21%, 95% confidence interval, 18% to 24%; vs 11 or more cases per year: 12%, 95% confidence interval, 8% to 16%; P < .001) and TBAD (fewer than 2 cases per year: 18%, 95% confidence interval, 15% to 22%; vs 11 or more cases per year: 9%, 95% confidence interval, 5% to 12%; P < .001), whereas TEVAR did not differ between quartiles. Adjusted mortality was lower at centers with 26 or more overall annual thoracic dissection repairs, compared with any of the three lower-volume quartiles (P < .001).

CONCLUSIONS

This study demonstrated lower mortality at high-volume hospitals for overall repair of aortic dissection, persisting separately for surgical repair of TAAD and TBAD, but not TEVAR. As endovascular technology advances and practice patterns consequently change, analyses should focus on understanding the balance between procedural volume, mortality, and access to care for thoracic aortic dissection.