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Bozzetto M, Remuzzi A, Valen-Sendstad K. Flow-induced high frequency vascular wall vibrations in an arteriovenous fistula: a specific stimulus for stenosis development? Phys Eng Sci Med 2024; 47:187-197. [PMID: 38157188 DOI: 10.1007/s13246-023-01355-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 11/12/2023] [Indexed: 01/03/2024]
Abstract
Hemodialysis is the lifeline for nearly three million end stage renal disease patients worldwide. Native arteriovenous fistula (AVF) is the preferred vascular access, but 40% fail within 1 year. We recently demonstrated that AVFs harbour transitional flows and the goal of the present study was to investigate whether the associated high-frequency pressure fluctuations could promote vibrations within the vascular wall. We acquired MRI images and flow rates immediately after surgery in one patient and generated a 3D patient-specific model. High-fidelity fluid structure interaction simulations revealed the presence of wall vibrations in distinct frequency bands up to 200 Hz and amplitude of 200 μm. A sensitivity analysis to assess the impact of flow rates, and vascular wall stiffness and thickness, changes that typically occur during AVF maturation, confirmed the robustness of the results. Interestingly, the vibrations were always predominant at the anastomosis floor and on the inner venous side, which correlates with typical stenotic regions. As studies seeking to correlate aberrant stresses and vascular remodelling have been largely inconclusive, the focal colocalization between vibrations and stenosis may suggest an unknown mechanobiological process between high-frequency mechanical stresses within the vascular wall and adverse vascular remodelling.
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Affiliation(s)
- Michela Bozzetto
- Bioengineering Department, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Ranica, BG, Italy
| | - Andrea Remuzzi
- Department of Management Information and Production Engineering, University of Bergamo, Via G.B. Marconi 5, Dalmine, BG, Italy.
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2
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Li Y, Hu K, Li Y, Lu C, Guo Y, Wang W. The rodent models of arteriovenous fistula. Front Cardiovasc Med 2024; 11:1293568. [PMID: 38304139 PMCID: PMC10830807 DOI: 10.3389/fcvm.2024.1293568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 01/09/2024] [Indexed: 02/03/2024] Open
Abstract
Arteriovenous fistulas (AVFs) have long been used as dialysis access in patients with end-stage renal disease; however, their maturation and long-term patency still fall short of clinical needs. Rodent models are irreplaceable to facilitate the study of mechanisms and provide reliable insights into clinical problems. The ideal rodent AVF model recapitulates the major features and pathology of human disease as closely as possible, and pre-induction of the uremic milieu is an important addition to AVF failure studies. Herein, we review different surgical methods used so far to create AVF in rodents, including surgical suturing, needle puncture, and the cuff technique. We also summarize commonly used evaluations after AVF placement. The aim was to provide recent advances and ideas for better selection and induction of rodent AVF models. At the same time, further improvements in the models and a deeper understanding of AVF failure mechanisms are expected.
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Affiliation(s)
- Yuxuan Li
- Departmentof Vascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ke Hu
- Departmentof Vascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yiqing Li
- Departmentof Vascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Chanjun Lu
- Department of General Vascular Surgery, Wuhan No.1 Hospital & Wuhan Hospital of Traditional Chinese and Western Medicine, Wuhan, China
| | - Yi Guo
- Clinic Center of Human Gene Research, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- Cardiovascular Center, Liyuan Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Weici Wang
- Departmentof Vascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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3
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Baltazar S, Northrup H, Chang J, Somarathna M, Isayeva Waldrop T, Lee T, Shiu YT. Effects of endothelial nitric oxide synthase on mouse arteriovenous fistula hemodynamics. Sci Rep 2023; 13:22786. [PMID: 38123618 PMCID: PMC10733286 DOI: 10.1038/s41598-023-49573-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 12/09/2023] [Indexed: 12/23/2023] Open
Abstract
Newly created arteriovenous fistulas (AVFs) often fail to mature for dialysis use due to disturbed blood flow at and near the AVF anastomosis. The disturbed flow inhibits the endothelial nitric oxide synthase (NOS3) pathway, thus decreasing the production of nitric oxide, a vasodilator. Previously, our group reported that NOS3 expression levels affect AVF lumen size in a mouse model. In this study, we performed MRI-based computational fluid dynamics simulations to investigate the hemodynamical parameters (velocity, wall shear stress (WSS), and vorticity) in a mouse AVF model at day 7 and day 21 post-AVF creation using three NOS3 strains: overexpression (OE), knockout (KO), and wild-type (WT) control. This study is the first to reveal hemodynamics over time in mouse AVFs, consider spatial heterogeneity along the vein, and reveal the effect of NOS3 on the natural history of mouse AVF hemodynamics. From day 7 to day 21, OE has smoother streamlines and had significantly lower vorticity and WSS than WT and KO, suggesting that WSS was attempting to return to pre-surgery baseline, respectively. Our results conclude that the overexpression of NOS3 leads to desired optimal hemodynamics during AVF remodeling. Future studies can investigate enhancing the NOS3 pathway to improve AVF development.
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Affiliation(s)
- Shelly Baltazar
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, USA
- Division of Nephrology and Hypertension, Department of Internal Medicine, University of Utah, 30 N Mario Capecchi Drive, 3rd Floor South, Salt Lake City, UT, 84112, USA
| | - Hannah Northrup
- Division of Nephrology and Hypertension, Department of Internal Medicine, University of Utah, 30 N Mario Capecchi Drive, 3rd Floor South, Salt Lake City, UT, 84112, USA
| | - Joshua Chang
- Division of Nephrology and Hypertension, Department of Internal Medicine, University of Utah, 30 N Mario Capecchi Drive, 3rd Floor South, Salt Lake City, UT, 84112, USA
| | - Maheshika Somarathna
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Tatyana Isayeva Waldrop
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Timmy Lee
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
- Veterans Affairs Medical Center, Birmingham, AL, USA
| | - Yan-Ting Shiu
- Division of Nephrology and Hypertension, Department of Internal Medicine, University of Utah, 30 N Mario Capecchi Drive, 3rd Floor South, Salt Lake City, UT, 84112, USA.
- Veterans Affairs Medical Center, Salt Lake City, UT, USA.
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Waldrop TI, Graham C, Gard W, Ingle K, Ptacek T, Nguyen N, Lose B, Sethu P, Lee T. Biomimetic cardiac tissue chip and murine arteriovenous fistula models for recapitulating clinically relevant cardiac remodeling under volume overload conditions. Front Bioeng Biotechnol 2023; 11:1101622. [PMID: 36873372 PMCID: PMC9978753 DOI: 10.3389/fbioe.2023.1101622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 02/03/2023] [Indexed: 02/18/2023] Open
Abstract
Cardiovascular events are the primary cause of death among dialysis patients. While arteriovenous fistulas (AVFs) are the access of choice for hemodialysis patients, AVF creation can lead to a volume overload (VO) state in the heart. We developed a three-dimensional (3D) cardiac tissue chip (CTC) with tunable pressure and stretch to model the acute hemodynamic changes associated with AVF creation to complement our murine AVF model of VO. In this study, we aimed to replicate the hemodynamics of murine AVF models in vitro and hypothesized that if 3D cardiac tissue constructs were subjected to "volume overload" conditions, they would display fibrosis and key gene expression changes seen in AVF mice. Mice underwent either an AVF or sham procedure and were sacrificed at 28 days. Cardiac tissue constructs composed of h9c2 rat cardiac myoblasts and normal adult human dermal fibroblasts in hydrogel were seeded into devices and exposed to 100 mg/10 mmHg pressure (0.4 s/0.6 s) at 1 Hz for 96 h. Controls were exposed to "normal" stretch and experimental group exposed to "volume overload". RT-PCR and histology were performed on the tissue constructs and mice left ventricles (LVs), and transcriptomics of mice LVs were also performed. Our tissue constructs and mice LV both demonstrated cardiac fibrosis as compared to control tissue constructs and sham-operated mice, respectively. Gene expression studies in our tissue constructs and mice LV demonstrated increased expression of genes associated with extracellular matrix production, oxidative stress, inflammation, and fibrosis in the VO conditions vs. control conditions. Our transcriptomics studies demonstrated activated upstream regulators related to fibrosis, inflammation, and oxidative stress such as collagen type 1 complex, TGFB1, CCR2, and VEGFA and inactivated regulators related to mitochondrial biogenesis in LV from mice AVF. In summary, our CTC model yields similar fibrosis-related histology and gene expression profiles as our murine AVF model. Thus, the CTC could potentially play a critical role in understanding cardiac pathobiology of VO states similar to what is present after AVF creation and may prove useful in evaluating therapies.
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Affiliation(s)
- Tatyana Isayeva Waldrop
- Department of Medicine and Division of Nephrology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Caleb Graham
- Division of Cardiovascular Disease, University of Alabama at Birmingham, Birmingham, AL, United States
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, AL, United States
| | - William Gard
- Department of Medicine and Division of Nephrology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Kevin Ingle
- Department of Medicine and Division of Nephrology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Travis Ptacek
- Center for Clinical and Translational Science, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Nguyen Nguyen
- Department of Medicine and Division of Nephrology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Bailey Lose
- Department of Medicine and Division of Nephrology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Palaniappan Sethu
- Division of Cardiovascular Disease, University of Alabama at Birmingham, Birmingham, AL, United States
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Timmy Lee
- Department of Medicine and Division of Nephrology, University of Alabama at Birmingham, Birmingham, AL, United States
- Veterans Affairs Medical Center, Birmingham, AL, United States
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Ingle K, Pham L, Lee V, Guo L, Isayeva-Waldrop T, Somarathna M, Lee T. Cardiac changes following arteriovenous fistula creation in a mouse model. J Vasc Access 2023; 24:124-132. [PMID: 34144670 PMCID: PMC9013201 DOI: 10.1177/11297298211026083] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Arteriovenous fistula (AVF) creation may negatively affect cardiac structure and function and impact cardiovascular mortality. The objective of this study was to develop and characterize the cardiac changes following AVF creation in a murine AVF model. METHODS AVFs were constructed using the carotid artery and jugular vein in C57BL/6 mice. Sham-operated AVF mice served as the control group. 2D-echocardiography was performed prior to AVF creation (baseline) and at 7 and 21 days after creation in AVF and sham-operated mice. Picrosirius red was used to stain the left ventricle for collagen production. RESULTS The cardiac output (CO), left ventricular end diastolic (LVEDD) and systolic (LVESD) diameter, and end-diastolic (LVEDV) and systolic (LVESV) volume was significantly increased at 7 and 21 days in AVF compared to sham-operated mice. There was also a significant increase in CO, LVEDD, LVESD, LVEDV, and LVESV from baseline to 21 days within the AVF group, but not the sham-operated mice. There was a significant decrease in ejection fraction and fractional shortening at 21 days in AVF compared to sham-operated mice. Picrosirius red was significantly more prominent around both the perivascular and interstitial areas of the cardiac tissue from AVF mice compared to sham-operated AVF mice at 21 days. CONCLUSIONS The creation of an AVF in our murine model leads to cardiac changes such as increased cardiac output, left ventricular dilation, and cardiac fibrosis, while showing reductions of ejection fraction and fractional shortening.
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Affiliation(s)
- Kevin Ingle
- Department of Medicine and Division of Nephrology, University of Alabama at Birmingham, AL
| | - Linh Pham
- Department of Medicine and Division of Nephrology, University of Alabama at Birmingham, AL
| | - Viangkaeo Lee
- Department of Medicine and Division of Nephrology, University of Alabama at Birmingham, AL
| | - Lingling Guo
- Department of Medicine and Division of Nephrology, University of Alabama at Birmingham, AL
| | | | - Maheshika Somarathna
- Department of Medicine and Division of Nephrology, University of Alabama at Birmingham, AL
| | - Timmy Lee
- Department of Medicine and Division of Nephrology, University of Alabama at Birmingham, AL,Veterans Affairs Medical Center, Birmingham, AL
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Northrup H, He Y, Le H, Berceli SA, Cheung AK, Shiu YT. Differential hemodynamics between arteriovenous fistulas with or without intervention before successful use. Front Cardiovasc Med 2022; 9:1001267. [PMID: 36407418 PMCID: PMC9669082 DOI: 10.3389/fcvm.2022.1001267] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Accepted: 10/17/2022] [Indexed: 08/22/2023] Open
Abstract
A significant number of arteriovenous fistulas (AVFs) fail to maturate for dialysis. Although interventions promote maturation, functional primary patency loss is higher for AVFs with interventions (assisted maturation) than AVFs without interventions (un-assisted maturation). Although blood flow-associated hemodynamics have long been proposed to affect AVF remodeling, the optimal hemodynamic parameters for un-assisted maturation are unclear. Additionally, AVF maturation progress is generally not investigated until 6 weeks after AVF creation, and the examination is focused on the AVF's venous limb. In this exploratory study, patients (n = 6) underwent magnetic resonance imaging (MRI) at 1 day, 6 weeks, and 6 months after AVF creation surgery. Before successful use for hemodialysis, three AVFs required intervention and three did not. MRI of the AVFs were used to calculate lumen cross-sectional area (CSA) and perform computational fluid dynamics (CFD) to analyze hemodynamics, including velocity, wall shear stress (WSS), and vorticity. For the venous limb, the no-intervention group and intervention group had similar pre-surgery vein diameter and 1-day post-surgery venous CSA. However, the no-intervention group had statistically larger 1-day venous velocity (0.97 ± 0.67 m/s; mean ± SD), WSS (333 ± 336 dyne/cm2) and vorticity (1709 ± 1290 1/s) than the intervention group (velocity = 0.23 ± 0.10 m/s; WSS = 49 ± 40 dyne/cm2; vorticity = 493.1 ± 227 1/s) (P < 0.05). At 6 months, the no-intervention group had statistically larger venous CSA (43.5 ± 27.4 mm2) than the intervention group (15.1 ± 6.2 mm2) (P < 0.05). Regarding the arterial limb, no-intervention AVF arteries also had statistically larger 1-day velocity (1.17 ± 1.0 m/s), WSS (340 ± 423 dyne/cm2), vorticity (1787 ± 1694 1/s), and 6-month CSA (22.6 ± 22.7 mm2) than the intervention group (velocity = 0.64 ± 0.36 m/s; WSS = 104 ± 116 dyne/cm2, P < 0.05; vorticity = 867 ± 4551/s; CSA = 10.7 ± 6.0 mm2, P < 0.05). Larger venous velocity, WSS, and vorticity immediately after AVF creation surgery may be important for later lumen enlargement and AVF maturation, with the potential to be used as a tool to help diagnose poor AVF maturation earlier. However, future studies using a larger cohort are needed to validate this finding and determine cut off values, if any.
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Affiliation(s)
- Hannah Northrup
- Division of Nephrology and Hypertension, Department of Internal Medicine, University of Utah, Salt Lake City, UT, United States
| | - Yong He
- Division of Vascular Surgery and Endovascular Therapy, University of Florida, Gainesville, FL, United States
| | - Ha Le
- Division of Nephrology and Hypertension, Department of Internal Medicine, University of Utah, Salt Lake City, UT, United States
| | - Scott A. Berceli
- Division of Vascular Surgery and Endovascular Therapy, University of Florida, Gainesville, FL, United States
- Malcolm Randall Veterans Affairs Medical Center, Gainesville, FL, United States
| | - Alfred K. Cheung
- Division of Nephrology and Hypertension, Department of Internal Medicine, University of Utah, Salt Lake City, UT, United States
- Veterans Affairs Medical Center, Salt Lake City, UT, United States
| | - Yan-Ting Shiu
- Division of Nephrology and Hypertension, Department of Internal Medicine, University of Utah, Salt Lake City, UT, United States
- Veterans Affairs Medical Center, Salt Lake City, UT, United States
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7
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Rosado-Toro JA, Philip RC, Dunn ST, Celdran-Bonafonte D, He Y, Berceli SA, Roy-Chaudhury P, Tubaldi E. Functional analysis of arteriovenous fistulae in non-contrast magnetic resonance images. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2022; 222:106938. [PMID: 35738094 DOI: 10.1016/j.cmpb.2022.106938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 05/09/2022] [Accepted: 06/07/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND AND OBJECTIVE Arteriovenous fistulae (AVF) are the preferred mode of hemodialysis vascular access and their successful maturation is critical to reduce patient morbidity, mortality, cost, and improve quality of life. Peri-anastomotic venous segment stenosis is the primary cause of AVF maturation failure. The objective is to develop a software protocol for the functional analysis of arteriovenous fistula. METHOD We have developed a standard protocol for the anatomical analysis of the AVF to better understand the mechanisms involved in AVF stenosis and to identify future imaging biomarkers for AVF success or failure using non-contrast magnetic resonance imaging (MRI). The 3D model of the AVF is created using a polar dynamic programming technique. Analysis has been performed on six Yorkshire cross domestic swine, but techniques can be applied into clinical settings. RESULTS Differences in AVF angles and vein curvature are associated with significant variability of venous cross-sectional area. This suggests that the pattern of stenosis is likely to be dependent upon hemodynamic profiles which are largely determined by AVF anatomical features and could play an important role in AVF maturation. CONCLUSIONS This protocol enables us to visualize and study the hemodynamic profiles indirectly allowing early stratification of patients into high and low risk groups for AVF maturation failure. High risk patients could then be targeted with an enhanced process of care or future maturation enhancing therapies resulting in a much-needed precision-medicine approach to dialysis vascular access.
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Affiliation(s)
| | - Rohit C Philip
- BIO5 Institute, University of Arizona, Tucson, AZ, USA; Department of Electrical and Computer Engineering, College of Engineering, University of Arizona, Tucson, AZ, USA
| | - Samuel Thomas Dunn
- BIO5 Institute, University of Arizona, Tucson, AZ, USA; Department of Aerospace and Mechanical Engineering, College of Engineering, University of Arizona, Tucson, AZ, USA
| | | | - Yong He
- Department of Surgery, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Scott A Berceli
- Department of Surgery, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Prabir Roy-Chaudhury
- UNC Kidney Center, College of Medicine, University of North Carolina, Chapel Hill, NC, USA
| | - Eleonora Tubaldi
- Department of Mechanical Engineering, University of Maryland, College Park, MD, USA.
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8
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Itatani K, Sekine T, Yamagishi M, Maeda Y, Higashitani N, Miyazaki S, Matsuda J, Takehara Y. Hemodynamic Parameters for Cardiovascular System in 4D Flow MRI: Mathematical Definition and Clinical Applications. Magn Reson Med Sci 2022; 21:380-399. [PMID: 35173116 DOI: 10.2463/mrms.rev.2021-0097] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Blood flow imaging becomes an emerging trend in cardiology with the recent progress in computer technology. It not only visualizes colorful flow velocity streamlines but also quantifies the mechanical stress on cardiovascular structures; thus, it can provide the detailed inspections of the pathophysiology of diseases and predict the prognosis of cardiovascular functions. Clinical applications include the comprehensive assessment of hemodynamics and cardiac functions in echocardiography vector flow mapping (VFM), 4D flow MRI, and surgical planning as a simulation medicine in computational fluid dynamics (CFD).For evaluation of the hemodynamics, novel mathematically derived parameters obtained using measured velocity distributions are essential. Among them, the traditional and typical parameters are wall shear stress (WSS) and its related parameters. These parameters indicate the mechanical damages to endothelial cells, resulting in degenerative intimal change in vascular diseases. Apart from WSS, there are abundant parameters that describe the strength of the vortical and/or helical flow patterns. For instance, vorticity, enstrophy, and circulation indicate the rotating flow strength or power of 2D vortical flows. In addition, helicity, which is defined as the cross-linking number of the vortex filaments, indicates the 3D helical flow strength and adequately describes the turbulent flow in the aortic root in cases with complicated anatomies. For the description of turbulence caused by the diseased flow, there exist two types of parameters based on completely different concepts, namely: energy loss (EL) and turbulent kinetic energy (TKE). EL is the dissipated energy with blood viscosity and evaluates the cardiac workload related to the prognosis of heart failure. TKE describes the fluctuation in kinetic energy during turbulence, which describes the severity of the diseases that cause jet flow. These parameters are based on intuitive and clear physiological concepts, and are suitable for in vivo flow measurements using inner velocity profiles.
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Affiliation(s)
- Keiichi Itatani
- Department of Cardiovascular Surgery, Osaka City University.,Cardio Flow Design Inc
| | - Tetsuro Sekine
- Department of Radiology, Nippon Medical School Musashi Kosugi Hospital
| | - Masaaki Yamagishi
- Department of Pediatric Cardiovascular Surgery, Kyoto Prefectural University of Medicine
| | - Yoshinobu Maeda
- Department of Pediatric Cardiovascular Surgery, Kyoto Prefectural University of Medicine
| | - Norika Higashitani
- Cardio Flow Design Inc.,Department of Cardiovascular Surgery, Kyoto Prefectural University of Medicine
| | | | - Junya Matsuda
- Department of Cardiovascular Medicine, Nippon Medical School
| | - Yasuo Takehara
- Department of Fundamental Development for Advanced Low Invasive Diagnostic Imaging, Nagoya university Graduate School of Medicine
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Somarathna M, Hwang PT, Millican RC, Alexander GC, Isayeva-Waldrop T, Sherwood JA, Brott BC, Falzon I, Northrup H, Shiu YT, Stubben CJ, Totenhagen J, Jun HW, Lee T. Nitric oxide releasing nanomatrix gel treatment inhibits venous intimal hyperplasia and improves vascular remodeling in a rodent arteriovenous fistula. Biomaterials 2022; 280:121254. [PMID: 34836683 PMCID: PMC8724452 DOI: 10.1016/j.biomaterials.2021.121254] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 11/08/2021] [Accepted: 11/10/2021] [Indexed: 01/03/2023]
Abstract
Vascular access is the lifeline for hemodialysis patients and the single most important component of the hemodialysis procedure. Arteriovenous fistula (AVF) is the preferred vascular access for hemodialysis patients, but nearly 60% of AVFs created fail to successfully mature due to early intimal hyperplasia development and poor outward remodeling. There are currently no therapies available to prevent AVF maturation failure. First, we showed the important regulatory role of nitric oxide (NO) on AVF development by demonstrating that intimal hyperplasia development was reduced in an overexpressed endothelial nitric oxide synthase (NOS3) mouse AVF model. This supported the rationale for the potential application of NO to the AVF. Thus, we developed a self-assembled NO releasing nanomatrix gel and applied it perivascularly at the arteriovenous anastomosis immediately following rat AVF creation to investigate its therapeutic effect on AVF development. We demonstrated that the NO releasing nanomatrix gel inhibited intimal hyperplasia formation (more than 70% reduction), as well as improved vascular outward remodeling (increased vein diameter) and hemodynamic adaptation (lower wall shear stress approaching the preoperative level and less vorticity). Therefore, direct application of the NO releasing nanomatrix gel to the AVF anastomosis immediately following AVF creation may enhance AVF development, thereby providing long-term and durable vascular access for hemodialysis.
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Affiliation(s)
- Maheshika Somarathna
- Department of Medicine and Division of Nephrology, University of Alabama at Birmingham, AL, 35294, USA
| | - Patrick Tj Hwang
- Department of Biomedical Engineering, University of Alabama at Birmingham, AL, 35294, USA; Endomimetics, LLC, Birmingham, AL, 35242, USA
| | | | - Grant C Alexander
- Department of Biomedical Engineering, University of Alabama at Birmingham, AL, 35294, USA; Endomimetics, LLC, Birmingham, AL, 35242, USA
| | - Tatyana Isayeva-Waldrop
- Department of Medicine and Division of Nephrology, University of Alabama at Birmingham, AL, 35294, USA
| | | | - Brigitta C Brott
- Endomimetics, LLC, Birmingham, AL, 35242, USA; Department of Medicine and Division of Cardiovascular Disease, University of Alabama at Birmingham, AL, 35233, USA
| | - Isabelle Falzon
- Division of Nephrology and Hypertension, Department of Internal Medicine, University of Utah, Salt Lake City, UT, 84132, USA
| | - Hannah Northrup
- Division of Nephrology and Hypertension, Department of Internal Medicine, University of Utah, Salt Lake City, UT, 84132, USA
| | - Yan-Ting Shiu
- Division of Nephrology and Hypertension, Department of Internal Medicine, University of Utah, Salt Lake City, UT, 84132, USA; Veterans Affairs Medical Center, Salt Lake City, UT, 84148, USA
| | - Chris J Stubben
- Bioinformatics Shared Resource, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT, 84112, USA
| | - John Totenhagen
- Department of Radiology, University of Alabama at Birmingham, AL, 35294, USA
| | - Ho-Wook Jun
- Department of Biomedical Engineering, University of Alabama at Birmingham, AL, 35294, USA; Endomimetics, LLC, Birmingham, AL, 35242, USA
| | - Timmy Lee
- Department of Medicine and Division of Nephrology, University of Alabama at Birmingham, AL, 35294, USA; Veterans Affairs Medical Center, Birmingham, AL, 35233, USA
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10
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Northrup H, Somarathna M, Corless S, Falzon I, Totenhagen J, Lee T, Shiu YT. Analysis of Geometric and Hemodynamic Profiles in Rat Arteriovenous Fistula Following PDE5A Inhibition. Front Bioeng Biotechnol 2021; 9:779043. [PMID: 34926425 PMCID: PMC8675087 DOI: 10.3389/fbioe.2021.779043] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 11/09/2021] [Indexed: 11/13/2022] Open
Abstract
Arteriovenous fistula (AVF) is essential for chronic kidney disease (CKD) patients on hemodialysis, but treatment for AVF maturation failure remains an unmet clinical need. Successful AVF remodeling occurs through sufficient lumen expansion to increase AVF blood flow and lumen area. Aberrant blood flow is thought to impair AVF remodeling, but previous literature has largely focused on hemodynamics averaged over the entire AVF or at a single location. We hypothesized that hemodynamics is heterogeneous, and thus any treatment's effect size is heterogeneous in the AVF. To test our hypothesis, we used the PDE5A inhibitor sildenafil to treat AVFs in a rat model and performed magnetic resonance imaging (MRI) based computational fluid dynamics (CFD) to generate a detailed spatial profile of hemodynamics in AVFs. 90 mg/kg of sildenafil was administered to rats in their drinking water for 14 days. On day 14 femoral AVFs were created in rats and sildenafil treatment continued for another 21 days. 21 days post-AVF creation, rats underwent non-contrast MRI for CFD and geometrical analysis. Lumen cross-sectional area (CSA) and flow rate were used to quantify AVF remodeling. Parameters used to describe aberrant blood flow include velocity magnitude, wall shear stress (WSS), oscillatory shear index (OSI), and vorticity. Geometrical parameters include arterial-venous (A-V) distance, anastomosis angle, tortuosity, and nonplanarity angle magnitude. When averaged across the entire AVF, sildenafil treated rats had significantly higher CSA, flow rate, velocity, WSS, OSI, and vorticity than control rats. To analyze heterogeneity, the vein was separated into zones: 0-5, 5-10, 10-15, and 15-20 mm from the anastomosis. In both groups: 1) CSA increased from the 0-5 to 15-20 zone; 2) velocity, WSS, and vorticity were highest in the 0-5 zone and dropped significantly thereafter; and 3) OSI increased at the 5-10 zone and then decreased gradually. Thus, the effect size of sildenafil on AVF remodeling and the relationship between hemodynamics and AVF remodeling depend on location. There was no significant difference between control and sildenafil groups for the other geometric parameters. Rats tolerated sildenafil treatment well, and our results suggest that sildenafil may be a safe and effective therapy for AVF maturation.
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Affiliation(s)
- Hannah Northrup
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, United States
- Division of Nephrology and Hypertension, University of Utah Department of Internal Medicine, Salt Lake City, UT, United States
| | - Maheshika Somarathna
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Savanna Corless
- Division of Nephrology and Hypertension, University of Utah Department of Internal Medicine, Salt Lake City, UT, United States
| | - Isabelle Falzon
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, United States
- Division of Nephrology and Hypertension, University of Utah Department of Internal Medicine, Salt Lake City, UT, United States
| | - John Totenhagen
- Department of Radiology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Timmy Lee
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
- Veterans Affairs Medical Center, Birmingham, AL, United States
| | - Yan-Ting Shiu
- Division of Nephrology and Hypertension, University of Utah Department of Internal Medicine, Salt Lake City, UT, United States
- Veterans Affairs Medical Center, Salt Lake City, UT, United States
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11
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Szabo B, Tanczos B, Varga A, Barath B, Ghanem S, Rezsabek Z, Al-Smadi MW, Nemeth N. Micro-Rheological Changes of Red Blood Cells in the Presence of an Arterio-Venous Fistula or a Loop-Shaped Venous Graft in the Rat. Front Physiol 2020; 11:616528. [PMID: 33391035 PMCID: PMC7775550 DOI: 10.3389/fphys.2020.616528] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 11/30/2020] [Indexed: 11/17/2022] Open
Abstract
Introduction: In case of kidney failure, hemodialysis is the primary kidney replacement technique. Several vascular access methods used for the therapy, one of which is the arterio-venous fistula (AVF). In the AVF, the blood flow is altered, which can elevate the mechanical stress on the red blood cells (RBCs). This can affect the RBC hemorheological properties, and it can further cause systemic changes. To lower the turbulence and shear stress, we performed a loop-shaped arterio-arterial venous interposition graft (loop-shaped graft) to compare its effect to the conventional AVF. Materials and Methods: Thirty male Wistar were used (permission registration Nr.: 25/2016/UDCAW). The animals were randomly divided into sham-operated, AVF, and loop groups (n = 10/each). The superficial inferior epigastric vein (SIEV) was used to create the AVF and the loop-shaped graft. Blood samples were taken before/after the surgery and at the 1st, 3rd, and 5th postoperative weeks. We measured hemorhelogical, hematological, and blood gas parameters. The microcirculation of the hind limbs was also monitored using Laser Doppler fluxmetry. Results: Hematocrit, RBC count, and hemoglobin decreased by the 1st postoperative week. The erythrocyte aggregation values significantly increased in the fistula group by the 5th week (6.43 ± 2.31 vs. 13.60; p < 0.0001; vs. before operation). At the postoperative 1st week in the loop group, the values showed a significant decrease in RBC deformability. During the maturation period, dominantly at the 5th week, all values were normalized. The operated hind limb's skin microcirculation significantly increased in the sham and loop group by the 1st week (39 ± 10.57 vs. 73.93 ± 1.97 BFU, p < 0.01). This increase wasn't observed in the fistula group probably due to a steal-effect. Conclusion: Unlike in the loop group, in the presence of the fistula, several rheological parameters have changed. The loop-shaped graft had only minimal impact on micro-rheological parameters.
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Affiliation(s)
- Balazs Szabo
- Department of Operative Techniques and Surgical Research, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Doctoral School of Clinical Medicine, University of Debrecen, Debrecen, Hungary
| | - Bence Tanczos
- Department of Operative Techniques and Surgical Research, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Doctoral School of Clinical Medicine, University of Debrecen, Debrecen, Hungary
| | - Adam Varga
- Department of Operative Techniques and Surgical Research, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Doctoral School of Clinical Medicine, University of Debrecen, Debrecen, Hungary
| | - Barbara Barath
- Department of Operative Techniques and Surgical Research, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Doctoral School of Clinical Medicine, University of Debrecen, Debrecen, Hungary
| | - Souleiman Ghanem
- Department of Operative Techniques and Surgical Research, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Doctoral School of Clinical Medicine, University of Debrecen, Debrecen, Hungary
| | - Zsofia Rezsabek
- Department of Operative Techniques and Surgical Research, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Mohammad Walid Al-Smadi
- Department of Operative Techniques and Surgical Research, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Norbert Nemeth
- Department of Operative Techniques and Surgical Research, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
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12
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Falzon I, Northrup H, Guo L, Totenhagen J, Lee T, Shiu YT. The geometry of arteriovenous fistulas using endothelial nitric oxide synthase mouse models. KIDNEY360 2020; 1:925-935. [PMID: 33117991 PMCID: PMC7591147 DOI: 10.34067/kid.0001832020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 07/30/2020] [Indexed: 11/27/2022]
Abstract
BACKGROUND Arteriovenous fistula (AVF) maturation failure is a significant clinical problem in the hemodialysis population. Geometric parameters of human AVFs were associated with AVF development, but causative studies are lacking. We characterized mouse AVF geometry using endothelial nitric oxide synthase (NOS3) mouse models. METHODS Carotid-jugular AVFs were created in NOS3 overexpression (OE), knockout (KO), and wild type (WT) mice. At 7 and 21 days postcreation, black-blood magnetic resonance images of AVFs were acquired and used to build three-dimensional reconstructions of AVF lumens. We used these reconstructions to calculate the lumen area, lumen centerline, and centerline-derived parameters: anastomosis angle, tortuosity, nonplanarity angle, and location of maximal distance between the feeding artery and AVF vein. Inter- and intrauser variabilities were also determined. RESULTS When all mice were considered, increased minimum AVF venous lumen area was accompanied by increased venous tortuosity and increased distance between the artery and vein, with both remaining in-plane with the anastomosis. At day 7, the lumen area of AVFs from all strains was 1.5- to 2.5-fold larger than native veins. Furthermore, at day 21, AVF lumen in NOS3 OE (4.04±1.43 mm2) was significantly larger than KO (2.74±1.34 mm2) (P<0.001) and WT (2.94±1.30 mm2) mice (p<0.001). At day 21, the location of maximal artery-vein distance on the vein was further away from the anastomosis in OE (4.49±0.66 mm) than KO (2.87±0.38 mm) (p=0.001). Other geometric parameters were not significantly different between mouse strains or time points. Inter- and intrauser variabilities were small, indicating the reliability and reproducibility of our protocol. CONCLUSIONS Our study presents a detailed characterization of mouse AVF geometry, and a robust protocol for future mechanistic studies to investigate the role of molecular pathways in AVF geometry. Identifying a geometry related to desired AVF remodeling can help inform surgery to enhance AVF maturation.
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Affiliation(s)
- Isabelle Falzon
- Department of Biomedical Engineering, University of Utah, Salt Lake City, Utah
- Division of Nephrology and Hypertension, Department of Internal Medicine, University of Utah, Salt Lake City, Utah
| | - Hannah Northrup
- Department of Biomedical Engineering, University of Utah, Salt Lake City, Utah
- Division of Nephrology and Hypertension, Department of Internal Medicine, University of Utah, Salt Lake City, Utah
| | - Lingling Guo
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - John Totenhagen
- Department of Radiology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Timmy Lee
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
- Veterans Affairs Medical Center, Birmingham, Alabama
| | - Yan-Ting Shiu
- Division of Nephrology and Hypertension, Department of Internal Medicine, University of Utah, Salt Lake City, Utah
- Veterans Affairs Medical Center, Salt Lake City, Utah
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13
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Colley E, Simmons A, Varcoe R, Thomas S, Barber T. Arteriovenous fistula maturation and the influence of fluid dynamics. Proc Inst Mech Eng H 2020; 234:1197-1208. [DOI: 10.1177/0954411920926077] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Arteriovenous fistula creation is the preferred vascular access for haemodialysis therapy, but has a large failure rate in the maturation period. This period generally lasts 6 to 8 weeks after surgical creation, in which the vein and artery undergo extensive vascular remodelling. In this review, we outline proposed mechanisms for both arteriovenous fistula maturation and arteriovenous fistula failure. Clinical, animal and computational studies have not yet shown a definitive link between any metric and disease development, although a number of theories based on wall shear stress metrics have been suggested. Recent work allowing patient-based longitudinal studies may hold the key to understanding arteriovenous fistula maturation processes.
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Affiliation(s)
- Eamonn Colley
- School of Mechanical Engineering, University of New South Wales, Sydney, NSW, Australia
| | - Anne Simmons
- School of Mechanical Engineering, University of New South Wales, Sydney, NSW, Australia
| | - Ramon Varcoe
- Prince of Wales Hospital, Sydney, NSW, Australia
| | | | - Tracie Barber
- School of Mechanical Engineering, University of New South Wales, Sydney, NSW, Australia
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14
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Stegmayr B, Willems C, Groth T, Martins A, Neves NM, Mottaghy K, Remuzzi A, Walpoth B. Arteriovenous access in hemodialysis: A multidisciplinary perspective for future solutions. Int J Artif Organs 2020; 44:3-16. [PMID: 32438852 PMCID: PMC7780365 DOI: 10.1177/0391398820922231] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In hemodialysis, vascular access is a key issue. The preferred access is an arteriovenous fistula on the non-dominant lower arm. If the natural vessels are insufficient for such access, the insertion of a synthetic vascular graft between artery and vein is an option to construct an arteriovenous shunt for punctures. In emergency situations and especially in elderly with narrow and atherosclerotic vessels, a cuffed double-lumen catheter is placed in a larger vein for chronic use. The latter option constitutes a greater risk for infections while arteriovenous fistula and arteriovenous shunt can fail due to stenosis, thrombosis, or infections. This review will recapitulate the vast and interdisciplinary scenario that characterizes hemodialysis vascular access creation and function, since adequate access management must be based on knowledge of the state of the art and on future perspectives. We also discuss recent developments to improve arteriovenous fistula creation and patency, the blood compatibility of arteriovenous shunt, needs to avoid infections, and potential development of tissue engineering applications in hemodialysis vascular access. The ultimate goal is to spread more knowledge in a critical area of medicine that is importantly affecting medical costs of renal replacement therapies and patients’ quality of life.
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Affiliation(s)
- Bernd Stegmayr
- Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden
| | - Christian Willems
- Department of Biomedical Materials, Institute of Pharmacy, Martin Luther University of Halle-Wittenberg, Halle, Germany
| | - Thomas Groth
- Department of Biomedical Materials, Institute of Pharmacy, Martin Luther University of Halle-Wittenberg, Halle, Germany.,Interdisciplinary Center of Material Research, Martin Luther University of Halle-Wittenberg, Halle, Germany
| | - Albino Martins
- 3B's Research Group, I3Bs-Research Institute on Biomaterials, Biodegradables and Biomimetics of University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark-Parque de Ciência e Tecnologia, Barco, Portugal
| | - Nuno M Neves
- 3B's Research Group, I3Bs-Research Institute on Biomaterials, Biodegradables and Biomimetics of University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark-Parque de Ciência e Tecnologia, Barco, Portugal
| | - Khosrow Mottaghy
- Department of Physiology, RWTH Aachen University, Aachen, Germany
| | | | - Beat Walpoth
- Department of Cardiovascular Surgery (Emeritus), University of Geneva, Geneva, Switzerland
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15
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Shiu YT, Rotmans JI, Geelhoed WJ, Pike DB, Lee T. Arteriovenous conduits for hemodialysis: how to better modulate the pathophysiological vascular response to optimize vascular access durability. Am J Physiol Renal Physiol 2019; 316:F794-F806. [PMID: 30785348 PMCID: PMC6580244 DOI: 10.1152/ajprenal.00440.2018] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 02/04/2019] [Accepted: 02/17/2019] [Indexed: 12/11/2022] Open
Abstract
Vascular access is the lifeline for patients on hemodialysis. Arteriovenous fistulas (AVFs) are the preferred vascular access, but AVF maturation failure remains a significant clinical problem. Currently, there are no effective therapies available to prevent or treat AVF maturation failure. AVF maturation failure frequently results from venous stenosis at the AVF anastomosis, which is secondary to poor outward vascular remodeling and excessive venous intimal hyperplasia that narrows the AVF lumen. Arteriovenous grafts (AVGs) are the next preferred vascular access when an AVF creation is not possible. AVG failure is primarily the result of venous stenosis at the vein-graft anastomosis, which originates from intimal hyperplasia development. Although there has been advancement in our knowledge of the pathophysiology of AVF maturation and AVG failure, this has not translated into effective therapies for these two important clinical problems. Further work will be required to dissect out the mechanisms of AVF maturation failure and AVG failure to develop more specific therapies. This review highlights the major recent advancements in AVF and AVG biology, reviews major clinical trials, and discusses new areas for future research.
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Affiliation(s)
- Yan-Ting Shiu
- Division of Nephrology, University of Utah , Salt Lake City, Utah
| | - Joris I Rotmans
- Department of Internal Medicine, Leiden University Medical Center , Leiden , The Netherlands
| | - Wouter Jan Geelhoed
- Department of Internal Medicine, Leiden University Medical Center , Leiden , The Netherlands
| | - Daniel B Pike
- Division of Nephrology, University of Utah , Salt Lake City, Utah
| | - Timmy Lee
- Department of Medicine and Division of Nephrology, University of Alabama at Birmingham , Birmingham, Alabama
- Veterans Affairs Medical Center , Birmingham, Alabama
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16
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Pike D, Shiu YT, Somarathna M, Guo L, Isayeva T, Totenhagen J, Lee T. Correction to: High resolution hemodynamic profiling of murine arteriovenous fistula using magnetic resonance imaging and computational fluid dynamics. THEORETICAL BIOLOGY & MEDICAL MODELLING 2019; 16:8. [PMID: 30967149 PMCID: PMC6454632 DOI: 10.1186/s12976-019-0104-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 03/26/2019] [Indexed: 12/03/2022]
Affiliation(s)
- Daniel Pike
- Department of Bioengineering, University of Utah, Salt Lake City, UT, USA.,Division of Nephrology and Hypertension, Department of Internal Medicine, University of Utah, Salt Lake City, UT, USA
| | - Yan-Ting Shiu
- Department of Bioengineering, University of Utah, Salt Lake City, UT, USA.,Division of Nephrology and Hypertension, Department of Internal Medicine, University of Utah, Salt Lake City, UT, USA
| | - Maheshika Somarathna
- Department of Medicine and Division of Nephrology, University of Alabama at Birmingham, 1720 2nd Ave South, Birmingham, AL, 35294-0007, USA
| | - Lingling Guo
- Department of Medicine and Division of Nephrology, University of Alabama at Birmingham, 1720 2nd Ave South, Birmingham, AL, 35294-0007, USA
| | - Tatyana Isayeva
- Department of Medicine and Division of Nephrology, University of Alabama at Birmingham, 1720 2nd Ave South, Birmingham, AL, 35294-0007, USA
| | - John Totenhagen
- Department of Radiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Timmy Lee
- Department of Medicine and Division of Nephrology, University of Alabama at Birmingham, 1720 2nd Ave South, Birmingham, AL, 35294-0007, USA. .,Veterans Affairs Medical Center, Birmingham, AL, USA.
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17
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Pike D, Shiu YT, Cho YF, Le H, Somarathna M, Isayeva T, Guo L, Symons JD, Kevil CG, Totenhagen J, Lee T. The effect of endothelial nitric oxide synthase on the hemodynamics and wall mechanics in murine arteriovenous fistulas. Sci Rep 2019; 9:4299. [PMID: 30862797 PMCID: PMC6414641 DOI: 10.1038/s41598-019-40683-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 02/19/2019] [Indexed: 11/12/2022] Open
Abstract
Creation of a hemodialysis arteriovenous fistula (AVF) causes aberrant vascular mechanics at and near the AVF anastomosis. When inadequately regulated, these aberrant mechanical factors may impede AVF lumen expansion to cause AVF maturation failure, a significant clinical problem with no effective treatments. The endothelial nitric oxide synthase (NOS3) system is crucial for vascular health and function, but its effect on AVF maturation has not been fully characterized. We hypothesize that NOS3 promotes AVF maturation by regulating local vascular mechanics following AVF creation. Here we report the first MRI-based fluid-structure interaction (FSI) study in a murine AVF model using three mouse strains: NOS3 overexpression (NOS3 OE) and knockout (NOS3−/−) on C57BL/6 background, with C57BL/6 as the wild-type control (NOS3+/+). When compared to NOS3+/+ and NOS3−/−, AVFs in the OE mice had larger lumen area. AVFs in the OE mice also had smoother blood flow streamlines, as well as lower blood shear stress at the wall, blood vorticity, inner wall circumferential stretch, and radial wall thinning at the anastomosis. Our results demonstrate that overexpression of NOS3 resulted in distinct hemodynamic and wall mechanical profiles associated with favorable AVF remodeling. Enhancing NOS3 expression may be a potential therapeutic approach for promoting AVF maturation.
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Affiliation(s)
- Daniel Pike
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, USA.,Division of Nephrology and Hypertension, Department of Internal Medicine, University of Utah, Salt Lake City, UT, USA
| | - Yan-Ting Shiu
- Division of Nephrology and Hypertension, Department of Internal Medicine, University of Utah, Salt Lake City, UT, USA.,Veterans Affairs Medical Center, Salt Lake City, UT, USA
| | - Yun-Fang Cho
- Division of Nephrology and Hypertension, Department of Internal Medicine, University of Utah, Salt Lake City, UT, USA
| | - Ha Le
- Division of Nephrology and Hypertension, Department of Internal Medicine, University of Utah, Salt Lake City, UT, USA
| | - Maheshika Somarathna
- Department of Medicine and Division of Nephrology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Tatyana Isayeva
- Department of Medicine and Division of Nephrology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Lingling Guo
- Department of Medicine and Division of Nephrology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - J David Symons
- Department of Nutrition and Integrative Physiology and Molecular Medicine Program, University of Utah, Salt Lake City, UT, USA.,Division of Endocrinology, Metabolism, and Diabetes, University of Utah, Salt Lake City, UT, USA
| | - Christopher G Kevil
- Departments of Pathology, Molecular and Cellular Physiology, and Cellular Biology and Anatomy, LSU Health Shreveport, Shreveport, LA, USA
| | - John Totenhagen
- Department of Radiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Timmy Lee
- Department of Medicine and Division of Nephrology, University of Alabama at Birmingham, Birmingham, AL, USA. .,Veterans Affairs Medical Center, Birmingham, AL, USA.
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