The mechanobiological theory: a unifying hypothesis on the pathogenesis of moyamoya disease based on a systematic review

OBJECTIVE Moyamoya angiopathy (MMA) affects the distal internal carotid artery and is designated as moyamoya disease (MMD) when predisposing conditions are absent, or moyamoya syndrome (MMS) when it occurs secondary to other causes. The authors aimed to investigate the reason for this anatomical site predilection of MMA. There is compelling evidence to suggest that MMA is a phenomenon that occurs due to stereotyped mechanobiological processes. Literature regarding MMD and MMS was systematically reviewed to decipher a common pattern relating to the development of MMA. METHODS A systematic review was conducted to understand the pathogenesis of MMA in accordance with PRISMA guidelines. PubMed MEDLINE and Scopus were searched using “moyamoya” and “pathogenesis” as common keywords and specific keywords related to six identified key factors. Additionally, a literature search was performed for MMS using “moyamoya” and “pathogenesis” combined with reported associations. A progressive search of the literature was also performed using the keywords “matrix metalloprotease,” “tissue inhibitor of matrix metalloprotease,” “endothelial cell,” “smooth muscle cell,” “cytokines,” “endothelin,” and “transforming growth factor” to infer the missing links in molecular pathogenesis of MMA. Studies conforming to the inclusion criteria were reviewed. RESULTS The literature search yielded 44 published articles on MMD by using keywords classified under the six key factors, namely arterial tortuosity, vascular angles, wall shear stress, molecular factors, blood rheology/viscosity, and blood vessel wall strength, and 477 published articles on MMS associations. Information obtained from 51 articles that matched the inclusion criteria and additional information derived from the progressive search mentioned above were used to connect the key factors to derive a network pattern of pathogenesis. CONCLUSIONS Based on the available literature, the authors have proposed a unifying theory for the pathogenesis of MMA. The moyamoya phenomenon appears to be the culmination of an interplay of vascular anatomy, hemodynamics, rheology, blood vessel wall strength, and a plethora of intricately linked mechanobiological molecular mediators that ultimately results in the mechanical process of occlusion of the blood vessel, stimulating angiogenesis and collateral blood supply in an attempt to perfuse the compromised brain.

Download Full-text

The Intravascular Generation of Fibrinogen Derivatives and the Blood Vessel Wall in Venous Thrombosis and Disseminated Intravascular Coagulation

Thrombosis and Haemostasis ◽

10.1055/s-0038-1651902 ◽

1977 ◽

Vol 38 (04) ◽

pp. 0831-0849 ◽

Cited By ~ 1

Author(s):

Gwendolyn J. Stewart

Keyword(s):

Blood Vessel ◽

Venous Thrombosis ◽

Vessel Wall ◽

Fluid Phase ◽

Primary Site ◽

Blood Vessel Wall ◽

Fibrin Deposition ◽

Tissue Destruction ◽

Fibrin Formation ◽

Rich Material

SummaryBoth deep venous thrombosis and DIC are intermediate mechanisms of disease – both are a consequence of the deposition of fibrin-rich material in blood vessels some distance from the primary site of tissue destruction. The great difference in the sites of fibrin deposition may depend on the extent and site of activation of the clotting mechanism. DIC likely occurs in the fluid phase of the blood as a consequence of massive fibrin formation while thrombosis results from limited fibrin formation at the interface between blood and vessel wall. Leukocytes may be essential for attaching thrombi to the vessel wall in many places.

Download Full-text

Eicosanoids and the blood vessel wall.

Circulation ◽

10.1161/01.cir.70.4.523 ◽

1984 ◽

Vol 70 (4) ◽

pp. 523-528 ◽

Cited By ~ 32

Author(s):

P J Cannon

Keyword(s):

Blood Vessel ◽

Vessel Wall ◽

Blood Vessel Wall

Download Full-text

An Ultraminiaturized MEMS Microbiopsy Tool for Trans Blood Vessel Wall Biopsies

2020 IEEE 33rd International Conference on Micro Electro Mechanical Systems (MEMS) ◽

10.1109/mems46641.2020.9056446 ◽

2020 ◽

Author(s):

Mikael Sandell ◽

Rikard Grankvist ◽

Stefan Jonsson ◽

Wouter M. van der Wijngaart ◽

Goran Stemme ◽

...

Keyword(s):

Blood Vessel ◽

Vessel Wall ◽

Blood Vessel Wall

Download Full-text

Expression and Role of the Calcium-Sensing Receptor in the Blood Vessel Wall

Current Pharmaceutical Biotechnology ◽

10.2174/138920109787847466 ◽

2009 ◽

Vol 10 (3) ◽

pp. 282-288 ◽

Cited By ~ 12

Author(s):

Guerman Molostvov ◽

Rosemary Bland ◽

Daniel Zehnder

Keyword(s):

Blood Vessel ◽

Vessel Wall ◽

Blood Vessel Wall ◽

Calcium Sensing Receptor ◽

Calcium Sensing

Download Full-text

Sinus Floor Augmentation—Associated Surgical Ciliated Cysts: Case Series and a Systematic Review of the Literature

Applied Sciences ◽

10.3390/app11041903 ◽

2021 ◽

Vol 11 (4) ◽

pp. 1903

Author(s):

Adrian Kahn ◽

Shlomo Matalon ◽

Rahaf Bassam Salem ◽

Lazar Kats ◽

Liat Chaushu ◽

...

Keyword(s):

Systematic Review ◽

Microscopic Examination ◽

Literature Search ◽

Case Series ◽

Systematic Literature Search ◽

Review Of The Literature ◽

Inclusion Criteria ◽

Sinus Floor Augmentation ◽

Sinus Floor

This study aimed to characterize the demographic and clinical features of underreported surgical ciliated cysts developing after sinus floor augmentation, based on a series of cases from our files and a systematic review of the literature. A series of five cases (four patients) of microscopically confirmed surgical ciliated cysts following sinus floor augmentation procedures from our files are described. A systematic literature search (1991–2020) with strict clinical-, radiological- and microscopic-based exclusion and inclusion criteria was performed to detect additional similar cases. The systematic review revealed only five cases that fulfilled the inclusion criteria. Altogether, surgical ciliated cysts associated with sinus floor augmentation have been rarely reported in the literature, and have not been characterized either demographically or clinically. Graft materials were diverse, implants were placed simultaneously, or up to two years post-augmentation. The associated surgical ciliated cysts developed between 0.5 and 10 years post-augmentation. Although limited in its extent, this study is the first series to characterize possible underreported sequelae of surgical ciliated cysts associated with sinus floor augmentation. It emphasizes the need for long post-operative follow-up and confirmation of lesion by microscopic examination.

Download Full-text

A Systematic Review of Librarian-Provided Services Delivered in Healthcare Settings Finds a Positive Effect on Clinician and Patient Relevant Outcomes and Identifies Gaps in the Evidence

Evidence Based Library and Information Practice ◽

10.18438/b83w45 ◽

2015 ◽

Vol 10 (1) ◽

pp. 95

Author(s):

Elizabeth Margaret Stovold

Keyword(s):

Systematic Review ◽

Conference Proceedings ◽

Data Collection ◽

Literature Search ◽

Healthcare Setting ◽

Risk Of Bias ◽

Randomised Trials ◽

Inclusion Criteria ◽

Healthcare Settings ◽

Positive Effect

A Review of: Perrier, L., Farrell, A., Ayala, A. P., Lightfoot, D., Kenny, T., Aaronson, E., . . . Weiss, A. ( 2014). Effects of librarian-provided services in healthcare settings: A systematic review. Journal of the American Medical Informatics Association, 21(6), 1118-1124. http://dx.doi.org/10.1136/amiajnl-2014-002825 Abstract Objective – To assess the effects of librarian-provided services, in any healthcare setting, on outcomes important to patients, healthcare providers, and researchers. Design – Systematic review and narrative synthesis. Setting – MEDLINE, CINAHL, ERIC, LISA, and CENTRAL databases; library-related websites, conference proceedings, and reference lists of included studies. Subjects – Twenty-five studies identified through a systematic literature search. Methods – In consultation with the review team, a librarian designed a search to be run in MEDLINE that was peer-reviewed against a published checklist. The team then conducted searches in the five identified databases, adapting the search as appropriate for each database. Authors also checked the websites of library and evidence based healthcare organisations, along with abstracts of relevant conference proceedings, to supplement the electronic search. Two authors screened the literature search results for eligible studies, and reached agreement by consensus. Studies of any librarian-delivered service in a healthcare setting, directed at either patients, clinicians of any type, researchers, or students, along with studies reporting outcomes relevant to clinicians, patients, or researchers, were eligible for inclusion. The authors assessed results initially on the titles and abstracts, and then on the full-text of potentially relevant reports. The data from included studies were then extracted into a piloted data extraction form, and each study was assessed for quality using the Cochrane EPOC risk of bias tool or the Newcastle-Ottawa scale. The results were synthesised narratively. Main Results – The searches retrieved a total of 25 studies that met the inclusion criteria, comprised of 22 primary papers and 3 companion reports. Authors identified 12 randomised trials, 4 controlled before-and-after studies, 3 cohorts, 2 non-randomised trials, and 1 case-control study. They identified three main categories of intervention: librarians teaching search skills; providing literature searching as a service; and a combination of the teaching and provision of search services. The interventions were delivered to a mix of trainees, clinicians, and students. None of the studies examined services delivered directly to patients or to researchers. The quality assessment found most of the studies had a mid- to high-risk of bias due to factors such as lack of random sequence generation, a lack of validated tools for data collection, or a lack of statistical analysis included in the study. Two studies measured patient relevant outcomes and reported that searches provided by librarians to clinicians had a positive impact on the patient’s length of stay in hospital. Five studies examined the effect of librarian provided services on outcomes important to clinicians, such as whether a literature search influenced a clinical decision. There was a trend towards a positive effect, although two studies found no significant difference. The majority of studies investigated the impact of training delivered to trainees and students on their literature search skills. Twelve of these studies found a positive effect of training on the recipients’ search skills, while three found no difference. The secondary outcomes considered by this review were satisfaction with the service (8 studies), relevance of the answers provided by librarians (2), and cost (3). The majority reported good satisfaction, and relevance. A cost benefit was found in 2 of 3 studies that reported this outcome. Conclusion – Authors report a positive effect of training on the literature search skills of trainees and students, and identified a benefit in the small number of studies that examined librarian services to clinicians. Future studies should use validated data collection tools, and further research should be conducted in the area of services provided to clinicians. Research is needed on the effect of librarian-provided services to patients and researchers as no studies meeting the inclusion criteria examining these two groups were identified by the literature search.

Download Full-text