Development And Early Clinical Results Of A New Tiny Titanium Fastener To Secure 6-0, 7-0, And 8-0 Polypropylene Suture
Eric Ndikumana1, Kyle C. Purrman2, Peter A. Knight1, Jude S. Sauer2.
1University of Rochester Medical Center, Rochester, NY, USA, 2LSI SOLUTIONS, Victor, NY, USA.
OBJECTIVE: The technical challenges of hand-tying 6-0, 7-0, and 8-0 polypropylene suture through small access sites impede widespread adoption of less invasive cardiac surgery. The availability of very small titanium fasteners to secure suture can offer a reliable and ergonomic alternative. Compelling preclinical development and early clinical use of this technology are presented.
METHODS: The novel manually powered automated knotting device features a rotating 3 mm shaft to remotely crimp a tiny titanium fastener (tTF) and trim suture tails with a single squeeze of its lever. Pre-clinical evaluations included a broad range of design and manufacturing verification and validation testing, extensive ex vivo, in vivo and cadaver tissue model studies, utilization of a large bore vascular wound closure model simulating chronic malignant hypertension (i.e., average pressures >360/240 mmHg, 90 bpm tachycardia for >6 weeks) and a device usability study performed by 15 practicing surgeons. After FDA 510(k) clearance in June 2021, 7 surgeons have used tTFs in open and less invasive coronary artery bypass operations.
RESULTS: During ~5 years of development, >1,500 prototype and production devices tested in engineering studies and multiple tissue models demonstrated reliability and strength beyond USP standards. An in vivo porcine experiment compared tTF use to hand tying (HT) across multiple types of wound closures; for example, ease of use rated “excellent” for 91% (39/43) of tTF vs. 21% (6/29) of HT, wound approximation as “excellent” 100% (43/43) vs 86% (25/29) and immediate hemostasis 95% (41/43) vs. 83% (24/29). Chronic supraphysiologic pressure testing demonstrated no tTF failures, suture breakage, or suture slippage in more than 5.5 million hypertensive pulses per fastener with more than 335 million cumulative pulses. Surgeon usability analysis indicate tTF facilitates rapid learning, superior ergonomics and excellent performance. In coronary surgery, 7 surgeons have successfully deployed 30 tTFs in 11 patients with excellent results.
CONCLUSION: The deployment of the tTFs presents an ergonomic, reliable alternative to hand-tied knots to secure small polypropylene suture. Preclinical testing supports the safety and efficacy of tTF technology. Early clinical success is encouraging, especially regarding the potential to enhance less invasive cardiac surgery.
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