Vascular Remodeling and Immune Cell Infiltration in Splenic Artery Aneurysms

Rupture of splenic artery aneurysms (SAAs) is associated with a high mortality rate. The aim of this study was to identify the features of SAAs. Tissue sections from SAAs were compared to nonaneurysmal splenic arteries using various stains. The presence of intraluminal thrombus (ILT), vascular smooth muscle cells (VSMCs), cluster of differentiation (CD)-68+ phagocytes, myeloperoxidase+ neutrophils, CD3+, and CD20+ adaptive immune cells were studied using immunofluorescence microscopy. Analysis of SAAs revealed the presence of atherosclerotic lesions, calcifications, and ILT. Splenic artery aneurysms were characterized by a profound vascular remodeling with a dramatic loss of VSMCs, elastin degradation, adventitial fibrosis associated with enhanced apoptosis, and increased matrix metalloproteinase 9 expression. We observed an infiltration of immune cells comprising macrophages, neutrophils, T, and B cells. The T and B cells were found in the adventitial layer of SAAs, but their organization into tertiary lymphoid organs was halted. We failed to detect germinal centers even in the most organized T/B cell follicles and these lymphoid clusters lacked lymphoid stromal cells. This detailed histopathological characterization of the vascular remodeling during SAA showed that lymphoid neogenesis was incomplete, suggesting that critical mediators of their development must be missing.

From bedside to bench: an evaluation of expectations and challenges encountered by young surgeons facing basic science

Background: The evolution of surgical practice may lead to increasing difficulties for surgeons to perform fundamental research. The aim of this study was to evaluate the expectations and the challenges encountered by young surgeons when starting basic science.Methods: A qualitative study was conducted in France. A written questionnaire was anonymously filled by the participants attending to the Master Degree in surgical science.Results: The study included 47 participants (median age: 28 years, 59.6% of men); 37 (78.7%) participants had applied for a grant for their salary and 32 (68.1%) had obtained it. Nine (19.1%) participants had planned to keep their usual clinical activity. The main motivations were the perspective to embark on an academic career (55.3%) and improvement of knowledge in science (38.3%). The main barriers encountered were the lack of time (70.2%), the lack of interest (27.7%), the lack of financial support (23.4%) and administrative difficulties (12.8%).Conclusion: This study identified main barriers that young surgeons have to face when getting involved in basic science underlining the need to improve institutional and financial support to ensure involvement of new generations of surgeons in surgical research.

Interleukin-6 Receptor Signaling and Abdominal Aortic Aneurysm Growth Rates

Supplemental Digital Content is available in the text.

Background:

The Asp358Ala variant (rs2228145; A>C) in the IL (interleukin)-6 receptor (IL6R) gene has been implicated in the development of abdominal aortic aneurysms (AAAs), but its effect on AAA growth over time is not known. We aimed to investigate the clinical association between the IL6R-Asp358Ala variant and AAA growth and to assess the effect of blocking the IL-6 signaling pathway in mouse models of aortic aneurysm rupture or dissection.

Methods:

Using data from 2863 participants with AAA from 9 prospective cohorts, age- and sex-adjusted mixed-effects linear regression models were used to estimate the association between the IL6R-Asp358Ala variant and annual change in AAA diameter (mm/y). In a series of complementary randomized trials in mice, the effect of blocking the IL-6 signaling pathways was assessed on plasma biomarkers, systolic blood pressure, aneurysm diameter, and time to aortic rupture and death.

Results:

After adjusting for age and sex, baseline aneurysm size was 0.55 mm (95% CI, 0.13–0.98 mm) smaller per copy of the minor allele [C] of the Asp358Ala variant. Change in AAA growth was −0.06 mm per year (−0.18 to 0.06) per copy of the minor allele; a result that was not statistically significant. Although all available worldwide data were used, the genetic analyses were not powered for an effect size as small as that observed. In 2 mouse models of AAA, selective blockage of the IL-6 trans-signaling pathway, but not combined blockage of both, the classical and trans-signaling pathways, was associated with improved survival (P<0.05).

Conclusions:

Our proof-of-principle data are compatible with the concept that IL-6 trans-signaling is relevant to AAA growth, encouraging larger-scale evaluation of this hypothesis.

Artificial intelligence in abdominal aortic aneurysm

OBJECTIVE

Abdominal aortic aneurysm (AAA) is a life-threatening disease, and the only curative treatment relies on open or endovascular repair. The decision to treat relies on the evaluation of the risk of AAA growth and rupture, which can be difficult to assess in practice. Artificial intelligence (AI) has revealed new insights into the management of cardiovascular diseases, but its application in AAA has so far been poorly described. The aim of this review was to summarize the current knowledge on the potential applications of AI in patients with AAA.

METHODS

A comprehensive literature review was performed. The MEDLINE database was searched according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The search strategy used a combination of keywords and included studies using AI in patients with AAA published between May 2019 and January 2000. Two authors independently screened titles and abstracts and performed data extraction. The search of published literature identified 34 studies with distinct methodologies, aims, and study designs.

RESULTS

AI was used in patients with AAA to improve image segmentation and for quantitative analysis and characterization of AAA morphology, geometry, and fluid dynamics. AI allowed computation of large data sets to identify patterns that may be predictive of AAA growth and rupture. Several predictive and prognostic programs were also developed to assess patients' postoperative outcomes, including mortality and complications after endovascular aneurysm repair.

CONCLUSIONS

AI represents a useful tool in the interpretation and analysis of AAA imaging by enabling automatic quantitative measurements and morphologic characterization. It could be used to help surgeons in preoperative planning. AI-driven data management may lead to the development of computational programs for the prediction of AAA evolution and risk of rupture as well as postoperative outcomes. AI could also be used to better evaluate the indications and types of surgical treatment and to plan the postoperative follow-up. AI represents an attractive tool for decision-making and may facilitate development of personalized therapeutic approaches for patients with AAA.

Endovascular aneurysm sealing as an alternative for the treatment of failed endovascular aneurysm repair

OBJECTIVE

The Nellix EndoVascular Aneurysm Sealing (EVAS) system has offered a novel approach in the treatment of abdominal aortic aneurysm (AAA). While it is currently indicated as a primary procedure in patients with infrarenal AAA with suitable anatomy according to the indications for use, a few studies aimed to address its potential interest in failed endovascular aneurysm repair (EVAR). The aim of this systematic review was to analyze the postoperative outcomes of patients with prior EVAR who underwent EVAS.

DESIGN OF THE STUDY

A literature search was performed according to Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines in May 2019 and included patients with prior EVAR who underwent EVAS. The publications had to report at least one of the basic postoperative outcomes (technical success rate, all-cause complications, mortality, length of in-hospital stay, length of stay in intensive care unit, the need of re-intervention).

RESULTS

Eleven studies fulfilled the inclusion criteria, for a total of 46 patients. EVAS was used to treat endoleaks in 45 cases (97.8%): 29 type Ia endoleaks (63%), 6 type IIIa endoleaks (13%), and 10 type IIIb endoleaks (21.7%). Standard EVAS procedure was performed in 21 patients (45.7%), and 25 patients (54.3%) had chimney-EVAS. The technical success was achieved in all the studies. Two patients (4.9%) died during the 30-day postoperative period, but no aneurysm-related mortality was reported. The presence of endoleaks was reported in five patients (9.8%) during the follow-up.

CONCLUSION

The results suggest the safety and the efficiency of EVAS in the treatment of complications following EVAR including type Ia, type IIIa, and type IIIb endoleaks. Further studies on larger cohorts and longer follow-up periods are required to confirm the interest of EVAS in the endovascular management of failed EVAR.

Fundamentals in Artificial Intelligence for Vascular Surgeons

Artificial intelligence (AI) corresponds to a broad discipline that aims to design systems, which display properties of human intelligence. While it has led to many advances and applications in daily life, its introduction in medicine is still in its infancy. AI has created interesting perspectives for medical research and clinical practice but has been sometimes associated with hype leading to a misunderstanding of its real capabilities. Here, we aim to introduce the fundamental notions of AI and to bring an overview of its potential applications for medical and surgical practice. In the limelight of current knowledge, limits and challenges to face as well as future directions are discussed.

Diabetes mellitus is not associated with worse vascular outcome following percutaneous transfemoral transcatheter aortic valve implantation

Background: Transcatheter aortic valve implantation (TAVI) is an alternative to open surgical aortic valve replacement and the impact of diabetes on vascular outcomes is worth of investigation. The aim of our study was to determine if diabetic patients had distinct pre-operative characteristics compared to non-diabetics and to evaluate the impact of the disease on vascular outcomes.Methods: Four hundred consecutive patients who underwent TAVI with percutaneous transfemoral access were retrospectively included. Vascular outcomes were classified according to the Valve Academic Research Consortium 2 classification.Results: Seventy-eight (19.5%) patients were diabetics. Compared to non-diabetics, diabetic patients were younger and had significantly higher body mass index (29.7+/- 0.7 kg/m² vs 26.8+/- 0.3, p < .0001), higher proportion of associated dyslipidemia (34.6% vs 11.5%, p < .0001) and arterial hypertension (60% vs 38.2%, p = .0009). Anatomical characteristics of the vascular access and procedural characteristics did not differ among the groups. No significant difference was observed in the incidence of major and minor vascular complications and 30-day post-operative mortality between diabetic and non-diabetic patients (2.6% vs 1.9%, p = .6916).Conclusion: Diabetes is not associated with worse vascular outcome following TAVI suggesting that the vascular access can be managed safely in these patients.

Relationship between metformin and abdominal aortic aneurysm

Abdominal aortic aneurysm (AAA) is a life-threatening disease and pharmacologic agents to treat the disease remain lacking for clinical practice. Epidemiologic studies have highlighted a negative association between the use of antidiabetic drugs, including metformin, and AAA. Metformin is well-known for its blood glucose-lowering effect, but its action on both metabolism and inflammatory response has led to propose it as a potential therapeutic target in several cardiovascular diseases. In this review, we summarize the current knowledge on the link between metformin and AAA. Based on the known effects of the drug on the aortic wall, translational applications and clinical trials investigating the interest of metformin in the management of patients with AAA are discussed.

Diabetes and aortic aneurysm: current state of the art

Aortic aneurysm is a life-threatening disease due to the risk of aortic rupture. The only curative treatment available relies on surgical approaches; drug-based therapies are lacking, highlighting an unmet need for clinical practice. Abdominal aortic aneurysm (AAA) is frequently associated with atherosclerosis and cardiovascular risk factors including male sex, age, smoking, hypertension, and dyslipidaemia. Thoracic aortic aneurysm (TAA) is more often linked to genetic disorders of the extracellular matrix and the contractile apparatus but also share similar cardiovascular risk factors. Intriguingly, a large body of evidence points to an inverse association between diabetes and both AAA and TAA. A better understanding of the mechanisms underlying the negative association between diabetes and aortic aneurysm could help the development of innovative diagnostic and therapeutic approaches to tackle the disease. Here, we summarize current knowledge on the relationship between glycaemic parameters, diabetes, and the development of aortic aneurysm. Cellular and molecular pathways that underlie the protective effect of diabetes itself and its treatment are reviewed and discussed, along with their potential implications for clinical translation.