Local biaxial deformation measurements are essential for the in-depth investigation of tissue properties and remodeling of the ascending thoracic aorta, particularly in aneurysm formation. Current clinical imaging modalities pose limitations around the resolution and tracking of anatomical markers. We evaluated a new intra-operative video-based method to assess local biaxial strains of the ascending thoracic aorta. In 30 patients undergoing open-chest surgery, we obtained repeated biaxial strain measurements, at low- and high-pressure conditions. Precision was very acceptable, with coefficients of variation for biaxial strains remaining below 20%. With our four-marker arrangement, we were able to detect significant local differences in the longitudinal strain as well as in circumferential strain. Overall, the magnitude of strains we obtained (range: 0.02–0.05) was in line with previous reports using other modalities. The proposed method enables the assessment of local aortic biaxial strains and may enable new, clinically informed mechanistic studies using biomechanical modeling as well as mechanobiological profiling.

Current management guidelines for ascending thoracic aortic aneurysms (aTAA) recommend intervention once ascending or sinus diameter reaches 5–5.5 cm or shows a growth rate of >0.5 cm/year estimated from echo/CT/MRI. However, many aTAA dissections (aTAAD) occur in vessels with diameters below the surgical intervention threshold of <55 mm. Moreover, during aTAA repair surgeons observe and experience considerable variations in tissue strength, thickness, and stiffness that appear not fully explained by patient risk factors. To improve the understanding of aTAA pathophysiology, we established a multi-disciplinary research infrastructure: The Maastricht acquisition platform for studying mechanisms of tissue–cell crosstalk (MAPEX). The explicit scientific focus of the platform is on the dynamic interactions between vascular smooth muscle cells and extracellular matrix (i.e., cell–matrix crosstalk), which play an essential role in aortic wall mechanical homeostasis. Accordingly, we consider pathophysiological influences of wall shear stress, wall stress, and smooth muscle cell phenotypic diversity and modulation. Co-registrations of hemodynamics and deep phenotyping at the histological and cell biology level are key innovations of our platform and are critical for understanding aneurysm formation and dissection at a fundamental level. The MAPEX platform enables the interpretation of the data in a well-defined clinical context and therefore has real potential for narrowing existing knowledge gaps. A better understanding of aortic mechanical homeostasis and its derangement may ultimately improve diagnostic and prognostic possibilities to identify and treat symptomatic and asymptomatic patients with existing and developing aneurysms.

Background: Ascending thoracic aortic aneurysm is a chronic degenerative pathology characterized by dilatation of this segment of the aorta. Clinical guidelines use aortic diameter and growth rate as predictors of rupture and dissection. However, these guidelines neglect the effects of tissue remodeling, which may affect wall thickness. The present study aims to systematically review observational studies to examine to what extent wall thickness is considered and measured in clinical practice. Methods: Using PubMed and Web of Science, studies were identified with data on ascending aortic wall thickness, morphology, aortic diameter, and measurement techniques. Results: 15 included studies report several methods by which wall thickness is measured. No association was observed between wall thickness and aortic diameter across included studies. Wall thickness values appear not materially different between aneurysmatic aortas and non-aneurysmal aortas. Conclusions: The effects on and consequences of wall thickness changes during ATAA formation are ill-defined. Wall thickness values for aneurysmatic aortas can be similar to aortas with normal diameters. Given the existing notion that wall thickness is a determinant of mechanical stress homeostasis, our review exposes a clear need for consistent as well as clinically applicable methods and studies to quantify wall thickness in ascending aortic aneurysm research.

Local biaxial deformation plays a pivotal role in evaluating the tissue state of the ascending aorta and in driving intramural cell-mediated tissue remodeling. Unfortunately, the absence of anatomical markers on the ascending aorta presents challenges in capturing deformation. Utilizing our established intra-operative biaxial strain measurement method, we delineated local biaxial deformation characteristics in patients undergoing aortic valve replacement and coronary artery bypass graft surgery recipients (n = 20), and Aortic Repair surgery patients (n = 47). Expectedly, mean circumferential strains positively correlated with pulse pressure and negatively correlated with age and diameter. A new observation was that the mean axial strains exhibited the same trend as the mean circumferential strains when correlated with pulse pressure, age and diameter. Interestingly, on analyzing local biaxial strains, our findings revealed higher circumferential strains (by 1 %) proximal to the heart compared to distal regions across the cohorts and within each patient cohort. Furthermore, no discernible regional strain distinctions were noted between the medial and lateral sides of the ascending aorta for the entire patient population and individual cohorts. Patients undergoing Aortic Repair surgery indicated lower strains (ranging from 1 to 3 %) as compared to the other cohort. Our approach holds the potential to establish a foundational framework for the integrated examination of the mechanical and biological conditions and their role in ascending aortic aneurysm development.

The aims of this study were to retrospectively assess the occurrence of complications or need for secondary wrist procedures after the Sauvé-Kapandji procedure, and to prospectively assess patient-reported outcomes at long-term follow-up. All patients treated with the Sauvé-Kapandji procedure in our tertiary referral hospital between January 2008 and September 2021 were identified and contacted to complete the Quick Disabilities of the Arm, Shoulder, and Hand and the Patient-Rated Wrist/Hand Evaluation outcome measures. In total, 30 patients, with a median follow-up of 82 months, were included in this study. Complications occurred in 6 of 30 patients, which resulted in six secondary wrist procedures. Mean Quick Disabilities of the Arm, Shoulder, and Hand and Patient-Rated Wrist/Hand Evaluation scores were 30.1 and 33.6, respectively. We conclude that in respect of long-term outcomes, the Sauvé-Kapandji procedure can still be deemed to be a useful procedure, especially in patients with few other reconstructive options. Level of evidence: IV

Aim: Current microsurgical procedures are limited by the physiological tremor and dexterity of the surgeon. The MicroSurgical Assistant (MUSA, Microsure), the world’s first robotic platform for (super)microsurgery can aid in resolving issues encountered during microsurgery. This study presents an overview of the operating times and Structured Assessment of Microsurgery Skills (SAMS) scores to assess the duration and quality of microsurgical anastomoses for three microsurgical procedures currently performed using the MUSA. Methods: This study integrates data from one ongoing randomized controlled trial focusing on robotic-assisted lymphaticovenous anastomosis, along with findings from two separate prospective pilot studies concerning digital nerve repair and free tissue transplantation. SAMS scores and time needed per anastomosis were used to evaluate the quality and learning curve of the MUSA-assisted procedures. Results: Thirty-five robotic-assisted procedures were analyzed, including 18 lymphaticovenous anastomoses, 9 digital nerve repairs, and 8 free tissue transplantations. All procedures showed a trend of a decrease in the time needed to perform the procedure. Moreover, the mean overall SAMS scores for all three procedures were rated above ‘satisfactory’, with all procedures demonstrating a consistent trend of increasing SAMS scores over time. Conclusion: The evaluation of anastomosis’ quality in the initial cohorts of patients undergoing robotic-assisted microsurgery using MUSA indicates satisfying outcomes across all three types of procedures. The reduction in anastomosis time and the improvement in SAMS scores imply an ongoing learning process among the operating surgeons. Subsequent reports are expected to provide information on reaching a plateau phase in procedural efficiency.