Date on Master's Thesis/Doctoral Dissertation
5-2016
Document Type
Master's Thesis
Degree Name
M. Eng.
Department
Bioengineering
Committee Chair
Koenig, Steven
Committee Member
Slaughter, Mark
Committee Member
Walsh, Kevin
Committee Member
Giridharan, Guruprasas
Committee Member
Soucy, Kevin
Abstract
Purpose: Left ventricular assist device (LVAD) therapy can be live-saving for advanced heart failure patients. Conventional anastomosis (surgical connection) of LVAD outflow grafts to the aorta requires aortic clamping and hand-suturing. Aortic clamping increases the risk for neurological complications. Hand-suturing may be time-consuming and requires significant surgical dexterity. There is currently no commercially available device for sutureless anastomosis of large vascular grafts (diameter > 5mm). To overcome these limitations, a prototype LVAD outflow graft anastomosis device (GrAD) that facilitates sutureless anastomosis was developed and tested to demonstrate proof-of-concept and feasibility for (1) secured attachment withstanding physiological pressures, and (2) comparable attachment strength to conventionally hand-sewn sutured anastomosis.
Methods: To demonstrate proof-of-concept, prototype GrADs were fabricated using a nitinol wire connector attached to a 15 mm graft, felt flanged cuff, and cyanoacrylate adhesive. To demonstrate feasibility, the GrAD was anastomosed to bovine descending aorta and tested in a mock flow loop over a range of static (0, 50, 100, 150, 200 mmHg) and dynamic pressures (normal, hypertension, heart failure, LVAD support) to quantify v leakage. The maximum pull-out force for the GrAD and sutured anastomosis were also measured after completing static and dynamic testing in the mock flow loop model.
Results: The GrAD remained securely attached during all static and dynamic pressure test conditions as evidenced by minimal leak rates during clinically equivalent normal (22.1 ± 9.3 ml/min), hypertension (23.1 ± 10.1 ml/min), heart failure (16.4 ± 6.4 ml/min), and LVAD support (16.4 ± 4.3 mL/min) test conditions. Significantly larger leak rates at normal dynamic pressure (120/80 mmHg) between the GrAD and previously reported results for hand-sutured anastomosis were not observed. Differences in peak pull-out force between GrAD (43.57 ± 17.31 N) and hand-sutured anastomosis (63.48 ± 8.72 N) were statistically indiscernible (paired t-test, p < 0.5). No indications of device damage were observed.
Conclusion: A prototype GrAD enabling a sutureless, adaptable, and angled LVAD outflow graft anastomosis was developed with preliminary feasibility testing demonstrating proof-of-concept. The proposed LVAD outflow GrAD may facilitate surgical implant by eliminating the need for hand-suturing, decrease implant time, and increase reliability and reproducibility with the potential to improve patient outcomes.
Recommended Citation
Choi, Young, "Development of a novel device for ventricular assist device outflow graft anastomosis." (2016). Electronic Theses and Dissertations. Paper 2370.
https://doi.org/10.18297/etd/2370
