Morphological predictor of remodelling of the descending thoracic aortic false lumen that remains patent after repair of acute type A dissection

Normalization of Snai1-mediated vessel dysfunction increases drug response in cancer

Blood vessels in tumors are often dysfunctional. This impairs the delivery of therapeutic agents to and distribution among the cancer cells. Subsequently, treatment efficacy is reduced, and dose escalation can increase adverse effects on non-malignant tissues. The dysfunctional vessel phenotypes are attributed to aberrant pro-angiogenic signaling, and anti-angiogenic agents can ameliorate traits of vessel dysfunctionality. However, they simultaneously reduce vessel density and thereby impede drug delivery and distribution. Exploring possibilities to improve vessel functionality without compromising vessel density in the tumor microenvironment, we evaluated transcription factors (TFs) involved in epithelial-mesenchymal transition (EMT) as potential targets. Based on similarities between EMT and angiogenic activation of endothelial cells, we hypothesized that these TFs, Snai1 in particular, might serve as key regulators of vessel dysfunctionality. In vitro, experiments demonstrated that Snai1 (similarly Slug and Twist1) regulates endothelial permeability, permissiveness for tumor cell transmigration, and tip/stalk cell formation. Endothelial-specific, heterozygous knock-down of Snai1 in mice improved vascular quality in implanted tumors. This resulted in better oxygenation and reduced metastasis. Notably, the tumors in Snai1KD mice responded significantly better to chemotherapeutics as drugs were transported into the tumors at strongly increased rates and more homogeneously distributed. Thus, we demonstrate that restoring vessel homeostasis without affecting vessel density is feasible in malignant tumors. Combining such vessel re-engineering with anti-cancer drugs allows for strategic treatment approaches that reduce treatment toxicity on non-malignant tissues.

Morphologic prognostic factor for thoracoabdominal aortic dilation after acute type A dissection repair

OBJECTIVES

Risk factors for late-term aortic dilation after acute type A aortic dissection repair have not been well examined. The goal of this study was to determine the relationship between the abdominal aortic true lumen location and thoraco-abdominal aortic dilation after surgical repair for acute type A aortic dissection.

METHODS

Patients who were preoperatively diagnosed with acute type A aortic dissection between April 2014 and July 2022 were included in this study. We evaluated the renal artery-level dissected aortic morphology and classified the study population into 2 groups: the ventral (those with the true lumen located on the ventral side) and the dorsal (other patients not assigned to the ventral group) groups, based on the location of the true lumen. Aortic dilation was defined as thoraco-abdominal aortic expansion ≥5 mm on 1-year postoperative computed tomography images.

RESULTS

We examined 49 surgical patients who were assigned to the ventral (n = 22) and dorsal (n = 27) groups. The number of patients with ≥5 mm thoraco-abdominal aortic dilation after the operation was significantly higher in the ventral group than in the dorsal group (90.9% vs 51.9%, P = 0.009). The multivariable logistic regression analysis showed that the ventral type was an independent prognostic factor for thoraco-abdominal aortic dilation after the operation (odds ratio, 6.01; 95% confidence interval, 1.56-23.77; P = 0.009).

CONCLUSIONS

The location of the true lumen of the abdominal aorta in acute type A aortic dissection may be a prognostic factor for thoraco-abdominal aortic dilation after surgical repair.

False lumen thrombosis after frozen elephant trunk procedure in acute and chronic aortic dissection

BACKGROUND

The clinical significance of the false lumen (FL) thrombosis after the thoracic aortic surgery consists in the correlation with aortic remodeling. The aim of the study was to analyze the incidence of the FL thrombosis of the thoracoabdominal aorta after the frozen elephant trunk (FET) procedure in acute and chronic aortic dissection.

METHODS

A total of 57 consecutive patients with type A and B aortic dissection (AD) underwent the FET procedure between March 2012 and December 2020 were included in a retrospective study. All of the patients were divided in two groups: acute (n=18) and chronic (n=39) AD. Early and 2-year outcomes were evaluated in both groups. Computed tomography scans were obtained along the entire aorta for the aortic status assessment.

RESULTS

There were no statistically significant differences in early mortality and postoperative outcomes in both groups. The 2-year survival rate in acute and chronic AD was 74.7%±10% vs. 71.4%±7% (p=0.573), respectively. In the follow-up, the FL thrombosis rate, changes of the true lumen and total aortic diameters did not differ significantly between the analyzed groups of patients. The freedom from negative aortic remodeling was 62.2%±26% in acute AD versus 76.2%±11% in chronic AD (p=0.853). One (5.6%) and 4 (10.3%) distal aortic re-interventions were performed in acute and chronic AD, respectively.

CONCLUSIONS

False lumen thrombosis rate after the FET procedure did not differ significantly in acute and chronic AD.