Biosynthetic Versus Polytetrafluoroethylene Graft in Extra-anatomical Bypass Surgery of Takayasu Arteritis Patients With Supra-aortic Disease

Management of Takayasu arteritis: a systematic literature review informing the 2018 update of the EULAR recommendation for the management of large vessel vasculitis

Objective

To collect available evidence on management of large vessel vasculitis to inform the 2018 update of the EULAR management recommendations.

Methods

Two independent systematic literature reviews were performed, one on diagnosis and monitoring and the other on drugs and surgical treatments. Using a predefined PICO (population, intervention, comparator and outcome) strategy, Medline, Embase and Cochrane databases were accessed. Eligible papers were reviewed and results condensed into a summary of findings table. This paper reports the main results for Takayasu arteritis (TAK).

Results

A total of 287 articles were selected. Relevant heterogeneity precluded meta-analysis. Males appear to have more complications than females. The presence of major complications, older age, a progressive disease course and a weaker inflammatory response are associated with a more unfavourable prognosis. Evidence for details on the best disease monitoring scheme was not found. High-quality evidence to guide the treatment of TAK was not found. Glucocorticoids are widely accepted as first-line treatment. Conventional immunosuppressive drugs and tumour necrosis factor inhibitors were beneficial in case series and uncontrolled studies. Tocilizumab failed the primary endpoint (time to relapse) in a randomised controlled clinical trial; however, results still favoured tocilizumab over placebo. Vascular procedures may be required, and outcome is better when performed during inactive disease.

Conclusions

Evidence to guide monitoring and treatment of patients with TAK is predominantly derived from observational studies with low level of evidence. Therefore, higher-quality studies are needed in the future.

Investigating the performance of four specific types of material grafts and their effects on hemodynamic patterns as well as on von Mises stresses in a grafted three-layer aortic model using fluid-structure interaction analysis

One of the important parts of the cardiac system is aorta which is the fundamental channel and supply of oxygenated blood in the body. Diseases of the aorta represent critical cardiovascular bleakness and mortality around the world. This study aims at investigation of hemodynamic parameters in a two-dimensional axisymmetric model of three-layer grafted aorta using fluid-structure interaction (FSI). It assumes that a damaged part of aorta, which may happen as a result of some diseases like aneurysm, dissection and post-stenotic dilatation, is replaced with a biomaterial graft. Four types of grafts materials so-called Polyurethane, Silicone rubber, Polytetrafluoroethylene (PTFE) and Dacron are considered in the present study. The assumption of linear elastic and isotropic material is set for the both aorta's wall and aforementioned grafts. Blood is considered as an incompressible and Newtonian fluid. The results indicate higher displacement in Polyurethane and silicone rubber in comparison with other two. Furthermore, results reveal that blood flow velocity has slightly higher values in PTFE and Dacron grafted models compared to Polyurethane and Silicone rubber ones. Even though there are some differences in hemodynamic patterns in these grafted models, they are not considerable as much as von Mises stresses across the graft-aorta intersections are. This study shows that the types of material grafts play an important role in the amount of stresses particularly at intersections of aorta and graft.

Clinical results of biologic prosthesis: A systematic review and meta-analysis of comparative studies

Background

Biologic prosthesis (BP) has been reported as a safe alternative to polytetrafluoroethylene (PTFE) in vascular reconstruction. However, efficacy of BP remains controversial. We, therefore, conducted a systematic review to summarize previous available evidences comparing the BP and PTFE in terms of clinical outcomes.

Materials and methods

A literature search of the MEDLINE and Scopus was performed to identify comparative studies reporting outcomes of BP, PTFE, and/or autologous veins graft (VG) in vascular access for hemodialysis or femoropopliteal bypass. The outcome of interest was graft patency. Two reviewers independently extracted data. Meta-analysis with a random-effect model was applied to pool a risk ratio (RR) across studies.

Results

Among 584 articles identified, 11 studies (4 randomized controlled trials (RCT) and 7 cohorts) comprising 2627 patients were eligible for pooling. Seven studies compared BP with PTFE and 3 studies compared PTFE with VG. Among BP vs PTFE, pooling based on 3 RCTs yielded the pooled RR of 1.54 (95% CI: 1.10, 2.16), indicating 54% higher graft patency in VG than PTFE. Adding the 7 cohorts in this pooling yield similar results with the pooled RR of 1.29 (95% CI: 1.15, 1.45). The pooled RR of graft patency for BP vs VG was 0.74 (95% CI, 0.55, 1.00), indicating 26% lower graft patency in BP than VG.

Conclusions

Our first meta-analysis indicated that the biosynthetic prosthesis might be benefit over PTFE by increasing graft patency. An updated meta-analysis or a large scale randomized control trial is required to confirm this benefit.

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This study summarized the gap of knowledge of clinical outcome when compare with biologic prosthesis and PTFE.

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This first meta-analysis was shown clearly about results and high performance of study were collected.

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For the conclusion, high efficacy of alternative treatment was shown, however, further study needed to confirm the results.