Vascular Assessment Research Articles

The Role of Local Flaps in Foot and Ankle Reconstruction: An Assessment of Outcomes Across 206 Patients with Chronic Wounds.

Reconstructive surgery has experienced a paradigm shift in favor of free flaps. Yet, local flaps may be of particular use in foot and ankle reconstruction among comorbid patient populations. Thus, we sought to better characterize long-term outcomes in this setting. A single-center, retrospective cohort study of patients undergoing local muscle and fasciocutaneous flaps of the foot and ankle from January 2010-November 2022 was performed. Flap were performed on wounds measuring 3x6cm or smaller, and flap selection depended on preoperative vascular assessment, Doppler findings, comorbidity profile, and wound location, depth, and geometry. Two-hundred and six patients met inclusion criteria. Median age was 61.0 years (IQR 16.8), and comorbidities included diabetes mellitus (DM; n=149/206, 72.3%) and peripheral arterial disease (PAD; n=105/206, 51.0%). Presentations included chronic, non-healing wounds (n=77/206, 39.1%) or osteomyelitis (n=45/206, 22.8%), and most frequently extended to the bone (n=128/206, 62.1%). Eighty-seven patients (n=87/206, 42.2%) received muscle flaps, while 119 received fasciocutaneous flaps (n=119/206, 57.8%). Six patients (n=6/206, 2.9%) necessitated return to the operating room, with thrombosis occurring in two cases (n=2/206, 1.0%). Flap success rate was 98.1%. By a median follow-up duration of 21.7 months (IQR 39.0), 45 patients (n=45/206, 21.8%) necessitated ipsilateral amputation, 73% (n=145/199) were ambulatory, and two deaths were related to the operated wound (n=2/49, 4.1%). Multivariate analysis revealed positive predictors of complications included DM, end-stage renal disease, and prior histories of venous thromboembolism or smoking. Local flaps remain a reliable option to reconstruct smaller defects of the foot and ankle in a highly comorbid population.

Hepatic-associated vascular morphological assessment to predict overt hepatic encephalopathy before TIPS: a multicenter study

BackgroundTo provide patients the chance of accepting curative transjugular intrahepatic portosystemic shunt (TIPS) rather than palliative treatments for portal hypertension-related variceal bleeding and ascites, we aimed to assess hepatic-associated vascular morphological change to improve the predictive accuracy of overt hepatic encephalopathy (HE) risks.MethodsIn this multicenter study, 621 patients undergoing TIPS were subdivided into training (413 cases from 3 hospitals) and external validation datasets (208 cases from another 3 hospitals). In addition to traditional clinical factors, we assessed hepatic-associated vascular morphological changes using maximum diameter (including absolute and ratio values). Three predictive models (clinical, hepatic-associated vascular, and combined) were constructed using logistic regression. Their discrimination and calibration were compared to test the necessity of hepatic-associated vascular assessment and identify the optimal model. Furthermore, to verify the improved performance of ModelC−V, we compared it with four previous models, both in discrimination and calibration.ResultsThe combined model outperformed the clinical and hepatic-associated vascular models (training: 0.814, 0.754, 0.727; validation: 0.781, 0.679, 0.776; p < 0.050) and had the best calibration. Compared to previous models, ModelC−V showed superior performance in discrimination. The high-, middle-, and low-risk populations displayed significantly different overt HE incidence (p < 0.001). Despite the limited ability of pre-TIPS ammonia to predict overt HE risks, the combined model displayed a satisfactory ability to predict overt HE risks, both in the low- and high-ammonia subgroups.ConclusionHepatic-associated vascular assessment improved the predictive accuracy of overt HE, ensuring curative chances by TIPS for suitable patients and providing insights for cirrhosis-related studies.Graphical

The Diagnostic Impact of Contrast-Enhanced Computed Tomography (CECT) in Evaluating Lymph Node Involvement in Colorectal Cancer: A Comprehensive Review.

Colorectal cancer (CRC) remains a significant global health burden, necessitating accurate staging and treatment planning for optimal patient outcomes. Lymph node involvement is a critical determinant of prognosis in CRC, emphasizing the importance of reliable imaging techniques for its evaluation. Contrast-enhanced computed tomography (CECT) has emerged as a cornerstone in CRC imaging, offering high-resolution anatomical detail and vascular assessment. This comprehensive review synthesizes the existing literature to evaluate the diagnostic impact of CECT in assessing lymph node involvement in CRC. Key findings highlight CECT's high sensitivity and specificity in detecting lymph node metastases, facilitating accurate staging and treatment selection. However, challenges such as limited resolution for small lymph nodes and potential false-positives call for a cautious interpretation. Recommendations for clinical practice suggest the integration of CECT into multidisciplinary treatment algorithms, optimizing imaging protocols and enhancing collaboration between radiologists and clinicians. Future research directions include refining imaging protocols, comparative effectiveness studies with emerging modalities, and prospective validation of CECT's prognostic value. Overall, this review stresses the pivotal role of CECT in CRC management and identifies avenues for further advancements in imaging-guided oncology care.

Arterial stiffness and aortic hemodynamics as predictors for new or worsening cardiovascular events in childhood cancer survivors: A report from the St. Jude lifetime cohort.

e24006 Background: Survival following childhood cancer has improved due to advances in treatment and supportive care. However, survivors are at high risk of cardiovascular diseases (CVDs) later in life. Aortic artery stiffening, captured by measuring the speed and magnitude of forward and reflected pulse waves, is an independent predictor of CVD and mortality in the general population. Methods: We evaluated associations between vascular function and new or worsening CVDs [coronary artery disease (CAD), cardiomyopathy, and hypertension (HTN)] among a subset (n = 249) of St. Jude Lifetime Cohort (SJLIFE) participants who had baseline vascular function assessment and returned for a standard follow up study visit (mean age at baseline (years) ± standard deviation: 34 ± 9 years, follow-up: 39 ± 9 years). CVD conditions were graded (dichotomized as grades 0-1 and 2-4) using the Common Terminology Criteria for Adverse Events (CTCAE). Aortic stiffness, brachial and aortic blood pressure (BP), and aortic wave reflection (augmented pressure, augmentation index (AIx), AIx adjusted to a heart rate of 75 beats/min (AIx75), time and magnitude of the forward and reflected waves) were assessed using wave separation analyses. T-tests were used to test mean values between the groups with higher (2-5) and lower (0-1) grades. These tests informed the selection of identified variables for multivariate logistic models, which were adjusted for age, sex, race, body mass index, physical activity, smoking status, drinking behavior and vasoactive medications. Results: Most participants had a history of Hodgkin lymphoma (53.8%) or leukemia (20.5%) and 25.7% other diagnoses. There were 169 (67.9%) participants who had cranial/neck radiation, 167 (67.9%) received anthracyclines, and 150 (60.2%) alkylating agents. At baseline 38.2% had ≥grade 2 HTN, 9.2% cardiomyopathy, and 4% CAD. Having ≥ grade 2 CVDs was significantly associated with augmented markers of brachial and aortic BP, arterial stiffness, and wave reflection. Regression analyses revealed that AIx75 ≥ 17% was associated with an increased risk of new or worsening HTN (odds ratio (OR) 3.29, 95% confidence interval (CI) 1.03-10.48) and new or worsening cardiomyopathy (OR 4.06, 95% CI 1.02-16.16) an average of 5 years after baseline vascular testing. Conclusions: Childhood cancer survivors diagnosed with grades 2-4 CVDs at a baseline visit had elevated aortic stiffness and augmented indices of wave reflection compared to those with &lt; grade 2 CVDs. Elevated AIx75 was associated with new or worsening HTN and cardiomyopathy five years later. Early detection and treatment of vascular dysfunction may ameliorate CVD late effects in childhood cancer survivors.

Patient-specific arterial input function for accurate perfusion assessment in intraoperative fluorescence imaging.

The arterial input function (AIF) plays a crucial role in correcting the time-dependent concentration of the contrast agent within the arterial system, accounting for variations in agent injection parameters (speed, timing, etc.) across patients. Understanding the significance of the AIF can enhance the accuracy of tissue vascular perfusion assessment through indocyanine green-based dynamic contrast-enhanced fluorescence imaging (DCE-FI). We evaluate the impact of the AIF on perfusion assessment through DCE-FI. A total of 144 AIFs were acquired from 110 patients using a pulse dye densitometer. Simulation and patient intraoperative imaging were conducted to validate the significance of AIF for perfusion assessment based on kinetic parameters extracted from fluorescence images before and after AIF correction. The kinetic model accuracy was evaluated by assessing the variability of kinetic parameters using individual AIF versus population-based AIF. Individual AIF can reduce the variability in kinetic parameters, and population-based AIF can potentially replace individual AIF for estimating wash-out rate ( ), maximum intensity ( ), ingress slope with lower differences compared with those in estimating blood flow, volume transfer constant ( ), and time to peak. Individual AIF can provide the most accurate perfusion assessment compared with assessment without AIF or based on population-based AIF correction.

The knowledge, attitudes, and practices of arteriovenous access assessment among hemodialysis nurses: A multicenter cross-sectional survey.

Hemodialysis nurses' cannulation technique, monitoring, and management methods can affect patients' vascular access longevity. An arteriovenous access assessment comprises a medical history and vascular assessment through physical examination and surveillance. However, further exploration is needed to fully understand hemodialysis nurses' knowledge, attitudes, and practices (KAP) in this area. Between June and July 2023, we recruited hemodialysis nurses from 21 cities in Guangdong Province using a convenience sampling method. Four questionnaires-the General Data Questionnaire, the KAP Scale of Arteriovenous Access Assessment among Hemodialysis Nurses, the Utrecht Work Engagement Scale, and the NASA Task Load Index-were utilized for data collection through the Questionnaire Star platform. Of the 530 hemodialysis nurses participating in the study, 458 (86.4%) had a valid response. The participants demonstrated moderate knowledge and practice levels regarding arteriovenous access assessment and exhibited positive attitudes. We identified several factors related to arteriovenous access assessment that predict KAP in hemodialysis nurses. These factors included years of experience as a hemodialysis nurse, whether a nurse's knowledge of physical examination was sufficient to meet clinical needs, whether a nurse had received training in performing physical examination, whether a nurse's department regularly checked the quality of physical examination, and nurses' levels of work engagement and mental workload. All factors explained 32.4% of the variance in participants' KAP regarding arteriovenous access assessment. Improving hemodialysis nurses' assessment of arteriovenous access is crucial to ensure optimal patient care. Dialysis center managers and educators should prioritize understanding hemodialysis nurses' KAP of arteriovenous access assessment and any factors influencing these areas.

Comparative study between ultrasound and MR enterography in evaluation of Crohn’s disease

BackgroundCrohn’s disease is a chronic inflammatory bowel disease that can affect any part of the gut. Endoscopy is the gold standard for diagnosis, but it only assesses mucosal lesions. Magnetic resonance enterography (MRE) can assess disease presence and activity, but it has limitations such as motion sensitivity, long scan time, and high cost. Bowel sonography has been introduced as a non-invasive, practical, safe, and low-cost technique to assess disease activity and complications. In our study we aim to assess the comparability of ultrasound to MRE in evaluation of patients with Crohn’s disease, and its complications.ResultsTwenty-five patients with 38 Crohn’s disease affected segments were evaluated by bowel ultrasound (BUS) and MRI enterography (MRE), where BUS and MRE showed equivalent diagnostic performance for disease detection and localization (97.4%, 100%), for sensitivity and specificity of both modalities. Peri-mural fluid (89.5%, 94.4%) and mural stratification loss (100%, 100%) showed high sensitivity and specificity by BUS compared to MRE, while for assessment of mural vascularity, BUS showed high sensitivity and specificity for high grade vascularity (100%, 83.3%), but low sensitivity and high specificity for low and moderate vascularity (0%–62.5%, 81.8%) compared to MRE. Complications including fistulae and abscessed were all correctly identified in BUS compared to MRE.ConclusionBUS showed comparable results to MRE for identification, localization, assessment of findings related to disease activity, and complications in cases of Crohn’s disease rendering it a viable alternative to MRE.

#2722 Hemodialysis vascular access flow assessment by ultrasound dilution method (NephroFlow™) and ultrafiltration method with NIKKISO DBB-EXA™

Abstract Background and Aims A functioning vascular access (VA) is needed to ensure optimal dialysis. Reduced or falling levels of VA flow volume (Qa) indicate VA dysfunction and predict thrombosis. Qa can be measured by a number of different techniques, most of all using dilution techniques such as ultrasound dilution to measure the amount of recirculation induced by reversal of blood lines. The NephroFlow™ hemodialysis monitor estimates Qa using ultrasound velocity measurements of flowing blood and their dilution with 0.9% NaCl. Nikisso DBB-EXATM dialysis machine has the capacity to measure the VA recirculation rate by photometry performing a controlled rise on ultrafiltration rate; Qa is subsequently estimated using the Krivitski formula. There is little literature on the comparison of the different methodologies, but it was described that the DBB-EXATM method underestimates Qa compared to others techniques [1]. Our study aims to compare the Qa between the NephroFlow™ ultrasound dilution technique and the Nikisso DBB-EXATM ultrafiltration method. Method We performed an observational study that included 45 hemodialysis patients followed at our unit. Measurements of VA flow using the NephroFlow® device and the Nikisso-EXATM Ultrafiltration method were performed in patients with a native arteriovenous fistula or a graft. They were hemodynamically stable without acute clinical conditions. Both studies were undertaken during the first 90 minutes of a mid-week dialysis session, under a constant dialysis blood pump flow with the ultrafiltration interrupted during the procedure after having reversed the dialysis lines. For each patient we calculated the average of two Qa evaluations conducted at Nikisso-EXATM, spaced 15 days apart, with an additional evaluation using NephroFlow® conducted between these assessments. Results Forty-five patients (male: 71.1%) with a mean age of 73.2 ± 8 years were selected. The main CKD causes were diabetic kidney disease (n = 13, 28.9%) and uncertain etiology (n = 13, 28.9%). The dialysis vintage of these patients was 142.6 months (minimum 19, maximum 168). An arteriovenous fistula was present in 38 patients (84.4%) and an arteriovenous graft in 7 patients (15.6%). In the entire group, the mean flow with NephroFlow™ was 986.9 ± 515 ml/min and with DBB-EXATM 859.7 ± 522 ml/min. The measured values of the two methods presented a significant positive correlation (by Pearson) (R = 0.822, P &amp;lt; 0.01) (Fig. 1). In the group of patients with arteriovenous fistula (n = 38, 84.4%), the mean flow with NephroFlow™ was 961.8 ± 395 ml/min and with DBB-EXATM 839.1 ± 577 ml/min. The measured values of the two methods presented a significant positive correlation (by Pearson) (R = 0.844, P &amp;lt; 0.01). In the group of patients with arteriovenous graft (n = 7, 15.6%), the mean flow with NephroFlow™ was 1017.3 ± 401 ml/min and with DBB-EXATM 909.2 ± 604 ml/min. The measured values of the two methods presented a significant positive correlation (by Pearson) (R = 0.906, P &amp;lt; 0.01). Conclusion We found a significantly positive correlation between the Qa measurements obtained using both methods. The measurement of Qa using the ultrafiltration method on Nikisso DBB-EXATM seems to be a valuable and easily implementable tool for VA surveillance in both arteriovenous fistula and grafts. However, a bigger number of studies are required in this field in order to clarify this correlation with an additional comparative analysis to assess the reproducibility of measurements.

A Miniaturized Endoscopic Device Integrating Raman Spectroscopy and Laser Speckle Technology Via an Image Fusion Algorithm for Intraoperative Identification and Functional Protection of Parathyroid Glands

Abstract The importance of parathyroid glands (PGs) protection is increasingly recognized by thyroid surgeons in the field of minimally invasive video-assisted thyroidectomy (MIVAT). However, current techniques for intra-operative identification and vascularity assessment of the PGs are contentious and complex. This study presents the design and validation of a miniaturized device for fusion near-infrared autofluorescence (NIRAF) based on Raman spectroscopy and laser speckle contrast imaging (LSCI) via an image fusion algorithm for functional protection of PGs in the MIVAT. Our light source components include an integrated light emitting diode (LED) light source fiber, an NIRAF optical fiber, an acquisition optical fiber, and a laser speckle optical fiber in the endoscopic system to achieve identification and vascularity assessment of PGs using a single endoscopic probe. It has been validated in ex vivo tissue experiments that the fluorescence intensity detected by the device was equivalent to that of the marker indocyanine green (ICG) in visual images and superior to that of the thyroid and all other tissues in the neck. Based on clinical studies, MIVAT using functional fluorescence endoscopy, compared with the White light pattern group, the NIRAF combined with LSCI modality group increased the number of intra-operative confirmations of the PGs (P &amp;lt; 0.001), declined the decrease in parathyroid hormone (PTH) (P &amp;lt; 0.05) and calcium levels (P &amp;lt; 0.05) on the first postoperative day, and reduced the incidence of symptomatic hypocalcemia (P &amp;lt; 0.05). Our device may reduce the incidence of postoperative permanent hypoparathyroidism. Application of an miniaturized functional fluorescence endoscope for real-time and label-free PGs identification and vascularity assessment in MIVAT could be realized.

Pediatric three-dimensional quantitative cardiovascular computed tomography.

High-resolution, isotropic, 3-dimensional (D) data from pediatric cardiovascular computed tomography (CT) offer great potential for the accurate quantitative evaluation of pediatric cardiovascular and pulmonary vascular diseases. Recent pilot studies using pediatric 3-D cardiovascular CT have shown promising results in assessing cardiac function in conditions such as tetralogy of Fallot, cardiac defects with a hypoplastic ventricle, Ebstein anomaly, and in quantifying myocardial mass. In addition, the quantitative assessment of pulmonary vascularity is useful for evaluating differential right-to-left pulmonary vascular volume ratio, the effectiveness of pulmonary angioplasty, and predicting pulmonary hypertension. These initial experiences could broaden the role of pediatric cardiovascular CT in clinical practice. Furthermore, the current barriers to its widespread use, pertinent solutions to these problems, and new applications are discussed. In this review, the 3-D quantitative evaluations of cardiac function and pulmonary vascularity using high-resolution pediatric cardiovascular CT data are illustrated.

Evaluation of image-pro plus assisted superb microvascular imaging for differential diagnosis of renal masses

ObjectivePrevious research on diagnostic assessment by superb microvascular imaging (SMI) were based on qualitative or semi-quantitative assessments of vascularity, which may be subjective and unrepeatable by different sonographers. This study aimed to evaluate diagnostic performance of SMI Image-pro Plus (IPP) based vascular index (VI) for malignant renal masses. MethodWe retrospectively reviewed 222 masses in 214 patients who underwent SMI between August 2019 and August 2022 in our study. We evaluated the diagnostic performance of blood flow via Alder grade, VI based on both IPP and SMI. ResultsThe kappa consistency of the Adler grade and VI for renal masses was classified among different observers were 0.765 and 0.824. The intra-observers correlation ecoefficiency (ICC) were 0.727 and 0.874. Benign renal masses were mainly Adler grade 0, grade I, and grade II, VI was 4.30 ± 4.27 (Range 0.98–16.42); while malignant masses were mainly Adler grade III, VI was 14.95 ± 10.94 (Range 0.79–56.89). VI was higher in malignant than benign masses (t = 15.638, P < 0.01). Among the malignant masses, the mean VI in clear cell renal cell carcinoma was higher than that in papillary renal cell carcinoma and chromophobe renal cell carcinoma (F = 30.659, P < 0.01). The sensitivity, specificity and accuracy of SMI were 80.00%, 71.15%, and 78.64%, respectively. The sensitivity, specificity, and accuracy were 60.59%, 88.46%, and 80.18% by using a VI of 7.95 as the cutoff value to identify malignant lesions from benign masses yielded. VI had better diagnostic efficiency than ultrasonic characteristics and Adler grade in benign and malignant differential diagnosis (Z = 4.851, P < 0.01; Z = 2.732, P < 0.01). ConclusionVI was higher in malignant than benign in renal masses. In malignant masses, VI in CCRCC was higher than that in papillary renal cell carcinoma and ChRCC. As a noninvasive examination, it had important clinical significance in the differential diagnosis of renal masses. VI from IPP may assist sonographer in distinguish renal malignances as a quantitative tool for vascularity.

Assessment of pulmonary vascular anatomy: comparing augmented reality by holograms versus standard CT images/reconstructions using surgical findings as reference standard

BackgroundWe compared computed tomography (CT) images and holograms (HG) to assess the number of arteries of the lung lobes undergoing lobectomy and assessed easiness in interpretation by radiologists and thoracic surgeons with both techniques.MethodsPatients scheduled for lobectomy for lung cancer were prospectively included and underwent CT for staging. A patient-specific three-dimensional model was generated and visualized in an augmented reality setting. One radiologist and one thoracic surgeon evaluated CT images and holograms to count lobar arteries, having as reference standard the number of arteries recorded at surgery. The easiness of vessel identification was graded according to a Likert scale. Wilcoxon signed-rank test and κ statistics were used.ResultsFifty-two patients were prospectively included. The two doctors detected the same number of arteries in 44/52 images (85%) and in 51/52 holograms (98%). The mean difference between the number of artery branches detected by surgery and CT images was 0.31 ± 0.98, whereas it was 0.09 ± 0.37 between surgery and HGs (p = 0.433). In particular, the mean difference in the number of arteries detected in the upper lobes was 0.67 ± 1.08 between surgery and CT images and 0.17 ± 0.46 between surgery and holograms (p = 0.029). Both radiologist and surgeon showed a higher agreement for holograms (κ = 0.99) than for CT (κ = 0.81) and found holograms easier to evaluate than CTs (p < 0.001).ConclusionsAugmented reality by holograms is an effective tool for preoperative vascular anatomy assessment of lungs, especially when evaluating the upper lobes, more prone to anatomical variations.Trial registrationClinicalTrials.gov, NCT04227444Relevance statementPreoperative evaluation of the lung lobe arteries through augmented reality may help the thoracic surgeons to carefully plan a lobectomy, thus contributing to optimize patients’ outcomes.Key points• Preoperative assessment of the lung arteries may help surgical planning.• Lung artery detection by augmented reality was more accurate than that by CT images, particularly for the upper lobes.• The assessment of the lung arterial vessels was easier by using holograms than CT images.Graphical

Detection of subclinical atherosclerosis using vascular ultrasound as a vascular risk assessment method. Simplified protocol

Cardiovascular disease secondary to atherosclerosis is the main cause of morbidity and mortality in the world. Cardiovascular risk stratification has proven to be an insufficient approach to detect those subjects who are going to suffer a cardiovascular event, which is why for years other markers have been sought to help stratify each individual with greater precision. Two-dimensional vascular ultrasound is a excellent method for vascular risk assessment.

Endothelial dysfunction in breast cancer survivors on aromatase inhibitors: changes over time

BackgroundBreast cancer is estimated to comprise about 290,560 new cases in 2022. Aromatase inhibitors (AIs) are recommended as adjuvant treatment for estrogen-receptor positive (ER+) breast carcinoma in postmenopausal women, which includes approximately two-thirds of all women with breast cancer. AIs inhibit the peripheral conversion of androgens to estrogen by deactivation of the aromatase enzyme, leading to a reduction in serum estrogen level in postmenopausal women with ER+ breast carcinoma. Estrogen is known for its cardiovascular (CV) protective properties through a variety of mechanisms including vasodilation of blood vessels and inhibition of vascular injury resulting in the prevention of atherosclerosis. In clinical trials and prospective cohorts, the long-term use of AIs can increase the risk for hypertension and hyperlipidemia. Studies demonstrate mixed results as to the impact of AIs on actual CV events and overall survival.MethodsA single arm longitudinal study of 14 postmenopausal women with ER+ breast cancer prescribed adjuvant AIs at the University of Minnesota (UMN). Subjects with a history of known tobacco use, hypertension, hyperlipidemia, and diabetes were excluded to eliminate potential confounding factors. Participants underwent routine labs, blood pressure assessments, and vascular testing at baseline (prior to starting AIs) and at six months. Vascular assessment was performed using the EndoPAT 2000 and HDI/PulseWave CR-2000 Cardiovascular Profiling System and pulse contour analysis on two occasions as previously described. Vascular measurements were conducted by one trained vascular technician. Assessments were performed in triplicate, and the mean indices were used for analyses. All subjects were on an AI at the follow-up visit. The protocol was approved by the UMN Institutional Review Board and all participants were provided written informed consent. Baseline and follow-up characteristics were compared using Wilcoxon signed-rank tests. Analyses were performed using R version 3.6.1 (R Foundation for Statistical Computing, Vienna, Austria).ResultsAfter six months of AI treatment, EndoPAT® ratio declined to a median 1.12 (Q1: 0.85, Q3: 1.86; p = 0.045; Figure 1) and median estradiol levels decreased to 2 pg/mL (Q1: 2, Q3: 3; p=0.052). There was no evidence of association between change in EndoPAT® and change in estradiol level (p = 0.91). There were no statistically significant changes in small or large arterial elasticity.ConclusionsWe hypothesize that long-term use of AI can lead to persistent endothelial dysfunction, and further investigation is necessary. In our study, patients were on AI for approximately 5-10 years. As a result, we do not have data on whether these changes, such as EndoPAT® ratio and the elasticity of small and large arterial, are reversible with discontinuation of AI. These findings set the stage for a larger study to more conclusively determine the association between AI exposure and cardiovascular outcomes. Further studies should evaluate for multivariate associations withmodifiable risk factors for CV disease.

Acute kidney injury causes subclinical renal and endothelial injury in female rats which predisposes to adverse outcomes of pregnancy

Clinical data report a 3-5-fold increase in adverse pregnancy outcomes, including preeclampsia and small for gestational age neonates, among women with a history of acute kidney injury (AKI) despite clinical recovery of renal function. We developed a rat model of pregnancy post-AKI: Sprague-Dawley (SD) rats undergo a bilateral renal-ischemia reperfusion and fully recover renal function as measured by creatinine clearance 30 days post-AKI. Rats are then mated and during pregnancy recovered AKI rats exhibit decreased creatinine clearance, increased uterine artery resistance, reduced plasma volume expansion, and decreased fetal growth compared to pregnant rats that received sham surgery. Healthy pregnancy demands robust renal and vascular adaptations. Whether subclinical renal and vascular injury persists following AKI in females, and whether this is exacerbated in pregnancy to drive the adverse pregnancy outcomes remains unknown. We tested the hypothesis that AKI results in subclinical renal and vascular injury that lingers into pregnancy. Female SD rats were randomized to 45-minute warm bilateral renal ischemia reperfusion or sham (N=6-8/grp) and renal and vascular injury assessments were made 30 days post-AKI/Sham (pre-pregnancy) or during pregnancy on gestational day 20 (GD20). Pre-pregnancy urine volume measured via metabolic cage was greater in post-AKI rats compared to sham (10±1 vs 21±2 ml/daily urine, p&lt;0.05). Urinary kidney injury marker-1 (KIM-1) measured via ELISA 30 days post-AKI/Sham was greater in pre-pregnant AKI rats compared to sham (9685±871 vs. 6399±198 pg/24 hrs urine, p&lt;0.05). Vascular function, measured via wire myography on 3rd order mesenteric arteries 30 days post-AKI/Sham, revealed decreased endothelial-dependent relaxation to acetylcholine (ACh) (concentration-response, 1 nM-10 μM, 2-way ANOVA, RM, *p&lt;0.05). GD20 urine volume (31±5 vs 19±2 ml/daily urine, p&lt;0.05) and KIM-1 levels (9125±673 vs 6380±297 pg/daily urine, p&lt;0.05) were elevated in post-AKI pregnant rats compared to sham pregnant rats. Mason Trichrome renal staining revealed greater glomerular fibrosis (0.93±0.08 vs 0.04±0.04, *p&lt;0.05) and tubular fibrosis (1.7±0.19 vs 0.0±0.0, *p&lt;0.05) in post-AKI pregnant rats vs. sham pregnant. Ultrastructural changes to the kidneys were evaluated via electron microscopy and further revealed extensive brush border loss, loss of mitochondrial structure and mitochondrial swelling in post-AKI pregnant rats compared to sham pregnant. Endothelial-dependent relaxation to ACh was also lower (2-way ANOVA, *p&lt;0.05), suggesting enhanced endothelial dysfunction in post-AKI pregnant rats vs. sham pregnant. Taken together, these data suggest that with a history of AKI, subclinical renal and vascular injury is present despite “recovery” of renal function using clinical definitions and may predispose to adverse pregnancy outcomes in pregnant women with a history of AKI. 1R01HL169576 4R00HL146948 1RO1DK134695 AHA967662. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

High altitude sojourn elicits divergent effects in aortic and carotid stiffness in healthy-young adults

High altitude exposure challenges the cardiovascular system to compensate for barometric pressure-mediated reductions in arterial oxygen content. Reductions in oxygen content elicit simultaneous increases in sympathetic nervous system activity and vasodilation that may have competing effects on changes in large artery stiffness. The objective of this study was to examine changes in aortic and carotid stiffness during high altitude sojourn in healthy, young adults. We hypothesized that short-term high-altitude sojourn would increase both aortic and carotid stiffness. 17 Generally healthy adults (23±4 yrs, 25.0±3.0 BMI, n=9 females) underwent vascular assessments in the supine position at 1400 m and after an 8-day incremental ascent to 4300 m. Aortic stiffness and carotid β-stiffness were derived from carotid-femoral pulse wave velocity (cfPWV) via applanation tonometry and right common carotid artery ultrasonography, with blood pressure assessed via oscillometry. Ascent from 1400 m to 4300 m resulted in decreased arterial oxygen saturation (-11±4 %, p&lt;0.001) and carotid β-stiffness (-4.48±2.73 au, p&lt;0.001), and increased cfPWV, (+54.98±78.10 cm/s, p=0.01) and mean arterial pressure (+4±7 mmHg, p=0.02). Changes in cfPWV, arterial oxygen saturation, and blood pressure were moderately to strongly correlated (r=-0.425-0.503, p=0.09-0.04). Our data suggest that short term exposure to high altitude has differential effects on carotid versus aortic stiffness despite increases in mean blood pressure. Increases in aortic stiffness appear related to hypoxia-induced reductions in arterial oxygen saturation and concomitant increases in blood pressure, while reductions in carotid stiffness may stem, in-part, from compensatory carotid artery dilation necessary to increase cerebral blood flow at high altitude. Additional research is necessary to further understand mechanisms underlying differential changes in large artery stiffness during high altitude sojourn. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Growing Trend to Adopt Speckle Variance Optical Coherence Tomography for Biological Tissue Assessments in Pre-Clinical Applications.

Speckle patterns are a generic feature in coherent imaging techniques like optical coherence tomography (OCT). Although speckles are granular like noise texture, which degrades the image, they carry information that can be benefited by processing and thereby furnishing crucial information of sample structures, which can serve to provide significant important structural details of samples in in vivo longitudinal pre-clinical monitoring and assessments. Since the motions of tissue molecules are indicated through speckle patterns, speckle variance OCT (SV-OCT) can be well-utilized for quantitative assessments of speckle variance (SV) in biological tissues. SV-OCT has been acknowledged as a promising method for mapping microvasculature in transverse-directional blood vessels with high resolution in micrometers in both the transverse and depth directions. The fundamental scope of this article reviews the state-of-the-art and clinical benefits of SV-OCT to assess biological tissues for pre-clinical applications. In particular, focus on precise quantifications of in vivo vascular response, therapy assessments, and real-time temporal vascular effects of SV-OCT are primarily emphasized. Finally, SV-OCT-incorporating pre-clinical techniques with high potential are presented for future biomedical applications.

Feasibility of Reduced Iodine Loads for Vascular Assessment Prior to Transcatheter Aortic Valve Implantation (TAVI) Using Spectral Detector CT.

Reduced iodine loads for computed tomography (CT)-based vascular assessment prior to transcatheter aortic valve implantation (TAVI) may be feasible in conjunction with a spectral detector CT scanner. This prospective single-center study considered 100 consecutive patients clinically referred for pre-TAVI CT. They were examined on a dual-layer detector CT scanner to obtain an ECG-gated cardiac scan and a non-ECG-gated aortoiliofemoral scan. Either a standard contrast media (SCM) protocol using 80 mL Iohexol 350 mgI/mL (iodine load: 28 gI) or a body-mass-index adjusted reduced contrast media (RCM) protocol using 40-70 mL Iohexol 350 mgI/mL (iodine load: 14-24.5 gI) were employed. Conventional images and virtual monoenergetic images at 40-80 keV were reconstructed. A threshold of 250 HU was set for sufficient attenuation along the arterial access pathway. A qualitative assessment used a five-point Likert scale. Sufficient attenuation in the thoracic aorta was observed for all patients in both groups using conventional images. In the abdominal, iliac, and femoral segments, sufficient attenuation was observed for the majority of patients when using virtual monoenergetic images (SCM: 96-100% of patients, RCM: 88-94%) without statistical difference between both groups. Segments with attenuation measurements below the threshold remained qualitatively assessable as well. Likert scores were 'excellent' for virtual monoenergetic images 50 keV and 55 keV in both groups (RCM: 1.2-1.4, SCM: 1.2-1.3). With diagnostic image quality maintained, it can be concluded that reduced iodine loads of 14-24.5 gI are feasible for pre-TAVI vascular assessment on a spectral detector CT scanner.

Assessment of Retinal Microvasculature and Choroidal Vascularity After Intra-arterial Chemotherapy for Retinoblastoma

PurposeTo evaluate changes in retinal microvascular density and choroidal vascularity in patients with retinoblastoma (RB) after intra-arterial chemotherapy (IAC). DesignRetrospective clinical cohort study. MethodsThis study included 12 unilateral RB eyes treated with IAC (RB tumour), 12 contralateral normal eyes (RB fellow), and 12 healthy controls. The macular retinal thickness and retinal microvascular structure, including foveal avascular zone (FAZ) area, the macular and peripapillary superficial vessel density (SVD) and deep vessel density (DVD), were measured by optical coherence tomography angiography (OCTA). The choroidal thickness (ChT) and choroidal vascularity, including total choroidal area (TCA), luminal area (LA), stromal area (SA) and Choroidal Vascularity Index (CVI), were measured by spectral-domain optical coherence tomography (SD-OCT). A comparison among the three groups was conducted, while the correlations among the parameters were analyzed. ResultsBetween the three cohorts, the foveal retinal thickness, the SVD, DVD, ChT, TCA, LA, SA and CVI were significantly lower in RB tumour compared to RB fellow and the control eyes (all P<0.01). There were no significant differences in the parameters between the contralateral and control eyes. The correlation analyses indicated a significant negative correlation between the total melphalan dose and foveal and parafoveal DVD, ChT, and LA. ConclusionsThe retinal microvascular density and choroidal vascularity were lower in unilateral RB treated with IAC, and seemed to be related to the total melphalan dose. Moreover there were no measurable changes in the contralateral eyes.

Marfan and Loeys-Dietz aortic phenotype: A potential tool for diagnosis and management

ObjectiveIn heritable aortic diseases, different vascular involvement may occur with potential variable implications in aortic dilation/dissection risk. This study aimed to analyze the aortic anatomy of individuals with Marfan syndrome and Loeys-Dietz syndrome to identify possible morphological differences. MethodsComputed tomography and magnetic resonance imaging of the thoracoabdominal aorta from the proximal supra-aortic vessels to the femoral bifurcation level of 114 patients with Marfan and Loeys-Dietz syndromes and 20 matched control subjects were examined. Aortic diameters, areas, length, and tortuosity were measured in different aortic segments using specific vessel analysis software. ResultsPatients with Marfan syndrome showed a higher prevalence of ascending aorta and aortic root dilation (P = .011), larger and longer aortic roots (P = .013) with pear-shaped phenotype, larger isthmus/descending aorta diameter ratio (P = .015), and larger suprarenal aorta and iliac arteries. Patients with Loeys-Dietz syndrome showed longer indexed segments and a significantly longer arch (P = .006) with type 2/3 arch prevalence (P = .097). Measurement ratios analysis provided cut-off values (aortic root to ascending aorta length/aortic root diameter, aortic root/sinotubular junction, aortic root/ascending aorta diameter) differentiating patients with Marfan syndrome from patients with Loeys-Dietz syndrome, even in the early stage of the disease. ConclusionsBoth syndromes show peculiar anatomic patterns at different aortic levels irrespective of aortic dilation and disease severity. These features may represent the expression of different genetic mutations on aortic development, with a potential impact on prognosis and possibly contributing to better management of the diseases. The systematic adoption of whole body imaging with magnetic resonance or computed tomography should always be considered, because they allow a complete vascular assessment with practical indicators of differential diagnosis.