Thoracoabdominal aortic aneurysms (TAAAs) are rare but serious conditions characterized by dilation of the aorta characterized by remodeling of the vessel wall, with changes in the elastin and collagen content. Individuals with Marfan syndrome have a genetic predisposition for elastic fiber fragmentation and elastin degradation and are prone to early aneurysm formation and progression. Our objective was to analyze the medial collagen characteristics through histological, polarized light microscopy, and electron microscopy methods across the thoracic and abdominal aorta in twenty-five patients undergoing open surgical repair, including nine with Marfan syndrome. While age at surgery differed significantly between the groups, maximum aortic diameter and aneurysm extent did not. Collagen content increased from thoracic to infrarenal segments in both cohorts, with non-Marfan patients exhibiting higher collagen percentages, notably in the infrarenal aorta (729.3 nm vs. 1068.3 nm, p = 0.02). Both groups predominantly displayed mature collagen fibers, with the suprarenal segment containing the highest proportion of less mature fibers. Electron microscopy revealed comparable collagen fibril diameters across segments irrespective of Marfan status. Our findings underscore non-uniform histological patterns in TAAAs and suggest that ECM remodeling involves mature collagen deposition, albeit with lower collagen content observed in the infrarenal aorta of Marfan patients.

Thoracoabdominal aortic aneurysms (TAAAs) are rare and often remain asymptomatic until rupture, leading to high morbidity and mortality. Elastin degradation, largely mediated by matrix metalloproteinases (MMPs), plays a central role in their pathogenesis. This study aimed to evaluate plasma desmosine (pDES), a specific biomarker of elastin breakdown, as a non-invasive tool for TAAA detection and risk stratification. In a prospective single-centre case–control study, 30 patients with TAAA and 30 age- and sex-matched controls were enrolled. Plasma pDES levels were quantified using liquid chromatography–tandem mass spectrometry (LC–MS/MS). Aortic wall samples from 12 patients were analysed for elastic fibre content and MMP expression by histology and western blotting. Statistical analyses included correlation testing, propensity score matching, and receiver operating characteristic (ROC) analysis. TAAA patients exhibited significantly higher pDES levels compared with controls (0.40 ± 0.31 vs. 0.22 ± 0.15 ng/mL; p < 0.001). pDES correlated positively with MMP-2 (ρ = 0.68, p = 0.02), TIMP-1 (ρ = 0.72, p = 0.01), and the proportion of elastic fibres in the aortic media (ρ = 0.61, p = 0.03). ROC analysis showed good diagnostic performance (AUC = 0.82), with a threshold of 0.27 ng/mL yielding 78.6% sensitivity and 76.7% specificity. Elevated pDES levels reflect aortic elastolytic activity and may serve as a promising biomarker for TAAA detection and risk assessment.

Background/Objectives: Postoperative organ complications following open thoracoabdominal aortic aneurysm (TAAA) repair pose significant challenges during the early postoperative period, where prompt detection is crucial for improving patient outcomes. Sepsis is often a central factor in these complications. This study investigates the perioperative dynamics of soluble urokinase plasminogen activator receptor (suPAR) plasma levels in TAAA patients undergoing elective surgical repair and evaluates its diagnostic potential for early detection of postoperative sepsis. Methods: In this retrospective, single-center study, 28 patients (mean age 52.6 ± 13.4 years; 67.9% male) underwent elective open TAAA repair between 2022 and 2024. Blood samples were collected at five perioperative time points, and suPAR levels were measured using ELISA. The primary endpoint was the onset of postoperative sepsis, with secondary endpoints including other organ complications. The predictive performance of suPAR levels was evaluated using Receiver Operator Characteristics (ROC) analysis. Results: Postoperative sepsis developed in 7 of 28 patients (25%), with the diagnostic criteria met at a mean of 9.7 ± 6.9 days. Baseline suPAR levels did not differ between groups; however, from 12 h after surgery, the sepsis group exhibited significantly higher serum concentrations (14.43 ng/mL vs. 7.23 ng/mL; p = 0.004), a difference that persisted throughout the first 24 h. At 24 h, suPAR had the highest predictive accuracy for sepsis, with an AUC of 0.90, 90% sensitivity, and 86% specificity at a 9 ng/mL cut-off (p < 0.001). Conclusions: Elevated suPAR levels in the early postoperative period are strongly associated with the later onset of sepsis. Early monitoring may enable timely intervention, potentially improving outcomes in this high-risk patient population.

Background/Objectives: Arterial wall compliance is a key biomechanical property influencing local hemodynamics, vascular remodeling, and surgical performance. Despite its clinical relevance, reference values in lower limb arteries remain insufficiently characterized. This systematic review and meta-analysis aimed to synthesize existing evidence on cross-sectional compliance (CC) of the common femoral artery (CFA), superficial femoral artery (SFA), and popliteal artery (PA) in healthy adults. Methods: A systematic literature search was performed according to PRISMA guidelines to identify studies reporting arterial wall compliance in healthy adults. Study characteristics, measurement techniques, and compliance values were extracted. Risk of bias was assessed using a QUADAS-2/COSMIN-based tool. Pooled estimates were calculated using random effects meta-analysis, PROSPERO CRD420251208399. Results: Thirty-four studies with a total of 3452 participants were included. Reported compliance values varied substantially. The pooled mean CC of the CFA was 0.95 (95%-CI 0.83–1.06, I² = 99.2%). Sex-specific analysis showed a pooled mean CC of 1.07 (95%-CI 0.87–1.28, I² = 99.0%) in males and 0.90 (95%-CI 0.75–1.05, I² = 83.6%) in females. Meta-regression of age, sex, and BMI did not significantly demonstrate association between these moderators and CC or explain observed heterogeneity. Extracted CC values of the SFA ranged from 0.17 to 0.50 mm²/kPa, and mean CC values of the PA ranged from 0.44 to 0.62 mm²/kPa. Conclusions: Available data on CC in lower limb arteries are limited and heterogeneous. Given the substantial between-study heterogeneity, the pooled estimates resulting from the meta-analysis should therefore be considered descriptive and should not be interpreted as definitive physiological reference values.