Modern diagnostics for type B aortic dissection

Short- and Long-term survival prediction in patients with acute type A aortic dissection undergoing open surgery

BACKGROUND

Acute Type A aortic dissection (ATAAD) is a life-threatening cardiovascular disease associated with high mortality rates, where surgical intervention remains the primary life-saving treatment. However, the mortality rate for ATAAD operations continues to be alarmingly high. To address this critical issue, our study aimed to assess the correlation between preoperative laboratory examination, clinical imaging data, and postoperative mortality in ATAAD patients. Additionally, we sought to establish a reliable prediction model for evaluating the risk of postoperative death.

METHODS

In this study, a total of 384 patients with acute type A aortic dissection (ATAAD) who were admitted to the emergency department for surgical treatment were included. Based on preoperative laboratory examination and clinical imaging data of ATAAD patients, logistic analysis was used to obtain independent risk factors for postoperative in-hospital death. The survival prediction model was based on cox regression analysis and displayed as a nomogram.

RESULTS

Logistic analysis identified several independent risk factors for postoperative in-hospital death, including Marfan syndrome, previous cardiac surgery history, previous renal dialysis history, direct bilirubin, serum phosphorus, D-dimer, white blood cell, multiple aortic ruptures and age. A survival prediction model based on cox regression analysis was established and presented as a nomogram. The model exhibited good discrimination and significantly improved the prediction of death risk in ATAAD patients.

CONCLUSIONS

In this study, we developed a novel survival prediction model for acute type A aortic dissection based on preoperative clinical features. The model demonstrated good discriminatory power and improved accuracy in predicting the risk of death in ATAAD patients undergoing open surgery.

Colloidally Stable P(DMA-AGME)-Ale-Coated Gd(Tb)F3:Tb3+(Gd3+),Yb3+,Nd3+ Nanoparticles as a Multimodal Contrast Agent for Down- and Upconversion Luminescence, Magnetic Resonance Imaging, and Computed Tomography

Multimodal imaging, integrating several modalities including down- and up-conversion luminescence, T ₁- and T ₂(T ₂*)-weighted MRI, and CT contrasting in one system, is very promising for improved diagnosis of severe medical disorders. To reach the goal, it is necessary to develop suitable nanoparticles that are highly colloidally stable in biologically relevant media. Here, hydrophilic poly(N,N-dimethylacrylamide-N-acryloylglycine methyl ester)-alendronate-[P(DMA-AGME)-Ale]-coated Gd(Tb)F₃:Tb³⁺(Gd³⁺),Yb³⁺,Nd³⁺ nanoparticles were synthesized by a coprecipitation method in ethylene glycol (EG) followed by coating with the polymer. The particles were tho-roughly characterized by a dynamic light scattering (DLS), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray energy dispersive spectroscopy (EDAX), selected area electron diffraction (SAED), elemental ana-lysis and fluorescence spectroscopy. Aqueous particle dispersions exhibited excellent colloidal stability in water and physiological buffers. In vitro toxicity assessments suggested no or only mild toxicity of the surface-engineered Gd(Tb)F₃:Tb³⁺(Gd³⁺),Yb³⁺,Nd³⁺ particles in a wide range of concentrations. Internalization of the particles by several types of cells, including HeLa, HF, HepG2, and INS, was confirmed by a down- and up-conversion confocal microscopy. Newly developed particles thus proved to be an efficient contrast agent for fluorescence imaging, T ₁- and T ₂(T ₂*)-weighted magnetic resonance imaging (MRI), and computed tomography (CT).

Atypical presentation of type B aortic dissection mimicking appendicitis managed medically

This is a case of a 53-year-old male patient with a history of hypertension who developed sudden onset of right lower quadrant pain. On arrival, chest X-ray showed prominent aortic arch without cardiomegaly. CT of the abdomen/pelvis showed aortic dissection in descending aorta without rupture. CT of the chest displayed sparing of ascending and aortic arch. Ultrasound Doppler of the kidney displayed mild renal artery stenosis. Differential diagnosis was acute appendicitis, acute ureteric and severe gastroenteritis. The patient was started on oral blood pressure (BP) medicine to titrate off intravenous nicardipine and esmolol drip. After 10 days, he was switched to oral BP medicine. His leg pain was resolved with normal palpable pulse. One week later, his kidney function worsened. Thus, Lasix and minoxidil were stopped. The patient had no chest/abdominal pain and was tolerating the medicine well during his 2-week follow-up. Acute aortic dissection can be a fatal clinical emergency. Timing is critical during diagnosis and management of patients.

Free-breathing black-blood CINE fast-spin echo imaging for measuring abdominal aortic wall distensibility: a feasibility study

The paper reports a free-breathing black-blood CINE fast-spin echo (FSE) technique for measuring abdominal aortic wall motion. The free-breathing CINE FSE includes the following MR techniques: (1) variable-density sampling with fast iterative reconstruction; (2) inner-volume imaging; and (3) a blood-suppression preparation pulse. The proposed technique was evaluated in eight healthy subjects. The inner-volume imaging significantly reduced the intraluminal artifacts of respiratory motion (p  =  0.015). The quantitative measurements were a diameter of 16.3  ±  2.8 mm and wall distensibility of 2.0  ±  0.4 mm (12.5  ±  3.4%) and 0.7  ±  0.3 mm (4.1  ±  1.0%) for the anterior and posterior walls, respectively. The cyclic cross-sectional distensibility was 35  ±  15% greater in the systolic phase than in the diastolic phase. In conclusion, we developed a feasible CINE FSE method to measure the motion of the abdominal aortic wall, which will enable clinical scientists to study the elasticity of the abdominal aorta.

Aortic dissection

Aortic dissection is a life-threatening condition caused by a tear in the intimal layer of the aorta or bleeding within the aortic wall, resulting in the separation (dissection) of the layers of the aortic wall. Aortic dissection is most common in those 65-75 years of age, with an incidence of 35 cases per 100,000 people per year in this population. Other risk factors include hypertension, dyslipidaemia and genetic disorders that involve the connective tissue, such as Marfan syndrome. Swift diagnostic confirmation and adequate treatment are crucial in managing affected patients. Contemporary management is multidisciplinary and includes serial non-invasive imaging, biomarker testing and genetic risk profiling for aortopathy. The choice of approach for repairing or replacing the damaged region of the aorta depends on the severity and the location of the dissection and the risks of complication from surgery. Open surgical repair is most commonly used for dissections involving the ascending aorta and the aortic arch, whereas minimally invasive endovascular intervention is appropriate for descending aorta dissections that are complicated by rupture, malperfusion, ongoing pain, hypotension or imaging features of high risk. Recent advances in the understanding of the underlying pathophysiology of aortic dissection have led to more patients being considered at substantial risk of complications and, therefore, in need of endovascular intervention rather than only medical or surgical intervention.