High-Frequency Three-Dimensional Lumen Volume Ultrasound Is a Sensitive Method to Detect Early Aneurysmal Change in Elastase-Induced Murine Abdominal Aortic Aneurysm

Objective The aim of this study was to investigate the reproducibility of anterior–posterior diameter (APdmax) and three-dimensional lumen volume (3DLV) measurements of abdominal aortic aneurysms (AAA) in a classical murine AAA model. We also compared the magnitude of change in the aortic size detected with each method of assessment. Methods Periadventitial application of porcine pancreatic elastase (PPE AAA) or sham surgery was performed in two cohorts of mice. Cohort 1 was used to assess for observer variability with the APdmax and 3DLV measurements. Cohort 2 highlighted the relationship between APdmax and 3DLV and changes in AAA detected. Results There was no significant observer variability detected with APdmax measurement. Similarly, no significant intraobserver variability was evident with 3DLV; however, a small but significant interobserver difference was present. APdmax and 3DLV measurements of PPE AAA significantly correlated. However, changes in the AAA morphology were detected earlier with 3DLV. Conclusion APdmax and 3DLV are both reliable methods for measuring an AAA. Both these methods correlate with each other. However, changes in AAA morphology were detected earlier with 3DLV, which is important to detect subtle but important changes to aortic geometry in a laboratory setting. 3DLV measurement of AAA is a simple, reproducible, and comprehensive method for assessing changes in disease morphology.

Volumetric remodeling evaluated after frozen elephant trunk by 3D technology in acute type A aortic dissection

Background: Three-dimensional reconstruction technology is used to measure the volume of the descending aorta and to evaluate the characteristics of the remodeling of the descending aorta with different lengths after frozen elephant trunk (FET) treatment of acute type A aortic dissection (ATAAD). Methods: Three-dimensional reconstruction of the computed tomography angiography (CTA) of 48 cases ATAAD patients preoperatively and 1-3 months postoperatively was performed to measure the total volume of the aorta lumen model, descending aorta lumen volume, abdominal arterial lumen volume, as well as the true lumen (TL) and false lumen (FL) of each segment. The postoperative volumetric ratio was subtracted from the preoperative volumetric ratio, and the final distinction was made according to our remodeling classification criteria. Result: There were 13 (76.47%) positive remodeling cases, 9 (42.86%) stable remodeling cases, and 2 (20.00%) negative remodeling cases in the long FET group. In the short FET group, there were 4 (23.53%) positive remodeling cases, 12 (57.14%) stable remodeling cases, and 8 (80.00%) negative remodeling cases. As shown above, the data was obtained from the volumetric measurement and the morphological analysis of the three-dimensional reconstruction model. Conclusion: According to our classification criteria, long FET can promote the positive remodeling of the descending aorta, and it is meaningful for three-dimensional reconstruction to be used in volume measurement and morphological research.

Effect of the ratio of vessel-specific volume to fractional myocardial mass on fractional flow reserve

This study aimed to examine whether the ratio of vessel-specific coronary arterial lumen volume to the fraction of myocardial mass (VR/MR) affects myocardial ischemia. We proposed a calculation method for VR/MR, and compared the ratio of total epicardial coronary arterial lumen volume to left ventricular myocardial mass (V/M) with VR/MR in predicting myocardial ischemia. VR/MR and V/M were computed using data from 205 patients with 241 stenosis vessel who underwent coronary computed tomography angiography (CTA), quantitative coronary angiography, and fractional flow reserve. The vessel-specific coronary arterial lumen volume (VR) was obtained from CTA by segmenting the coronary arterial lumen volume, while the vessel-specific fraction of myocardial mass (MR) was obtained by allometric scaling. The VR/MR was then calculated. The cut-off values of V/M (23.55 mm3/g) and VR/MR (12.98 mm3/g) were used to define equal groups of ischemic and non-ischemic patients, respectively. Using these cut-off values, the accuracy, specificity, sensitivity, positive predictive value, and negative predictive value of V/M were 60%, 76%, 45%, 57%, and 66%, and of VR/MR were 87%, 92%, 77%, 89%, and 83%, respectively. Patients have different VR/MR values in different stenotic coronary arteries. Clinically, VR/MR is a quantitative indicator of the risk of myocardial ischemia.

Gender interaction effect on coronary lumen volume to mass ratio after administration of sublingual GTN powder compared to tablet in coronary computed tomography angiography (CCTA)

Funding Acknowledgements Type of funding sources: None. Background Nitroglycerin (GTN) results in improved CCTA image quality and diagnostic accuracy due to vasodilation and improved contrast density. Although studies have shown that sublingual (SL) GTN spray has greater vasodilation and faster onset and duration of action compared to SL tablet, it is not commonly used due to cost. The comparative efficacy of SL GTN powder in CCTA is unknown. Purpose The purpose of this study is to determine whether SL GTN powder can increase the coronary lumen volume (V) and the coronary lumen volume to left myocardial mass ratio (V/M) compared to SL GTN tablet. Methods 34 patients (17 females) with 0.8 mg SL GTN powder and 34 patients (17 females) with 0.8 mg SL GTN tablet administration were included in this retrospective case-control study. GTN was given 5 minutes pre-CCTA on a 256 slice single-heartbeat CT. Inclusion criteria: CAD-RADS 0 or 1, precontrast LM + LAD AJ-130 CAC < 100, heart rate less than 75, phase of the cardiac cycle diastole, successful motion correction, Likert score 4 or 5, right- or co-dominance. The primary outcome assessed was left main plus left anterior descending (LM + LAD) V between GTN powder vs tablet. The secondary outcomes were LM + LAD V divided by 1) length of LM + LAD (derived mean area, A), and 2) M (V/M). The outcomes were measured by blinded PI with 17 yrs CCTA experience on GE workstation, 2020 version. Categorical variables were compared by Chi-Squared tests and continuous variables were compared between powder and tablet groups by unpaired t-tests if normally distributed, and Mann-Whitney U tests otherwise. Exploratory outcome analyses tested route of administration by sex interactions and main effects by Two-Way ANOVA’s. Further covariate-adjusted analyses were conducted using multiple linear regression models. Results Baseline characteristics were similar between powder and tablet administration. No statistically significant difference in median V, LM + LAD derived A , or median V/M was observed. A sex main effect demonstrated that females had significantly smaller V (630.6 mm3 vs 951.7 mm3, p< 0.0001) and A (4.2 mm2 vs 6.4 mm2, p< 0.0001) compared to males. These V and A sex differences were also observed when BMI or weight were included as covariates. When V and A were normalized by M, both revealed sex interactions depending on formulation. While males had higher normalized V and A in powder vs tablet (p < 0.04), females had the opposite with higher normalized V and A with tablet compared to powder (p < 0.04). Conclusions SL administration of the GTN powder 5 minutes before CCTA did not result in greater vasodilatory effect compared to the GTN tablet. However, gender interaction effects were observed, with greater V/M and A/M ratio in males with powder and greater V/M and A/M in women with tablet. These results suggest a potential differential gender effect based on the formulation of GTN. Prospective studies are warranted to evaluate these findings. Abstract Figure. LM + LAD Lumen Volume to LV Mass by Sex

One-Year Single-Center Results of the Multilayer Flow Modulator Stents for the Treatment of Type B Aortic Dissection

Purpose To report a single-center series of patients with type B aortic dissection treated with the Multilayer Flow Modulator (MFM). Materials and Methods Over a 36-month period, 23 patients (median age 53 years; 20 men) with complicated type B aortic dissections (2 acute, 5 subacute, and 16 chronic) were treated with the MFM. Primary endpoints of rupture or dissection-related death, overall mortality, and reintervention were evaluated using the Kaplan-Meier method; estimates for freedom from the endpoints are reported with the 95% confidence interval (CI). Secondary outcomes included technical success, adverse events, and aortic remodeling. Clinical and imaging data were collected preoperatively, directly postoperatively, and annually to 36 months for analysis using computational fluid dynamics (CFD). Results Initial technical success was 91.3%. The estimates of the endpoints at 12 months were 100% for freedom from rupture or aortic-related death, 95.7% for freedom from overall mortality, and 91.3% for freedom from reintervention. No device-related neurological or systemic complications occurred, and no additional reinterventions were needed during follow-up. A total of 144 branches overstented by the MFM remained patent. Morphologic analysis of the aortic dissection showed progressive true lumen volume increase (75.9%, p<0.001) with concomitant false lumen volume decrease (42.8%, p<0.001); the CFD analyses showed increased laminar flow. Conclusion In the current series, the MFM provided a safe and feasible treatment option for complicated acute, subacute, and chronic type B aortic dissections, with high technical success, low mortality, and active aortic remodeling. Further studies should elucidate the long-term safety of the MFM and its effectiveness in a larger patient cohort.

Halloysite nanotubes in polymer science: purification, characterization, modification and applications

Halloysite nanotubes (HNTs) are natural tubular materials, which show a number of attractive advantages such as the unique micro-spatial structure, large length-diameter ratio, high lumen volume, nontoxicity and widespread. The development of HNTs-based polymer composites expanded their applications in the fields of energy, catalysis, biomedicine, environmental protection and many others. This review will briefly summarize the purification, characterization and modification methods upon HNTs, in which the preparation and application of the HNTs-based polymer composites are emphasized. This paper may be beneficial for the development of novel strategies for the preparation of new libraries of HNTs-based polymer composites and the exploration of their applications.

Cell fate coordinates mechano-osmotic forces in intestinal crypt morphogenesis

Intestinal organoids derived from single cells undergo complex crypt-villus patterning and morphogenesis. However, the nature and coordination of the underlying forces remains poorly characterized. Through light-sheet microscopy and mechanical perturbations, we demonstrate that organoid crypt formation coincides with stark lumen volume reduction, which works synergistically with actomyosin-generated crypt apical and villus basal tension to drive morphogenesis. We analyse these mechanical features in a quantitative 3D biophysical model and detect a critical point in actomyosin tensions, above which crypt becomes robust to volume changes. Finally, via single-cell RNA sequencing and pharmacological perturbations, we show that enterocyte-specific expressed sodium/glucose cotransporter modulates lumen volume reduction via promoting cell swelling. Altogether, our study reveals how cell fate-specific changes in osmotic and actomyosin forces coordinate robust organoid morphogenesis.One Sentence SummaryEmergence of region-specific cell fates drive actomyosin patterns and luminal osmotic changes in organoid development