Ferromagnetic Heating for Vessel Sealing and Division: Utility and Comparative Study to Ultrasonic and Bipolar Technologies

FMsealer Open Shears

Authors: Jenwood Chen, MD, Preston K. Manwaring, MSEE, PhD, Robert R. Scott, BSME, Kim H. Manwaring, MD, Robert E. Glasgow, MD

First Published: April 14, 2015


Introduction. Vessel sealing technologies have improved surgical efficiency and outcomes. Ferromagnetic technology has potential utility in this area. The aim of this study was to evaluate ferromagnetic heating in sealing and dividing vessels.

Methods. A novel ferromagnetic (FM) sealer, FMsealer, was developed for sealing and dividing vessels. Using a swine in vivo model, the following endpoints were evaluated: (1) proof of concept, (2) 21-day survival surgery, and (3) comparison with ultrasonic (US) and/or bipolar (BP) devices for subjective outcomes. Seal burst strengths were measured in vitro. Mann-Whitney and Student’s t test were used.

Results. After showing proof of concept, 5 swine underwent survival splenectomy, nephrectomy, hysterectomy, and mesenteric vessel division (arteries ranging from 1 to 7 mm in diameter) with necropsy after day 21 showing no evidence of surgical site bleeding. FM was equivalent to BP in tissue retention and superior to BP in spread/tissue desiccation, sticking, and charring (P ≤ .01). The FM was superior to US and BP in speed of 10 cm mesentery division (mean ± SD seconds): FM (12.9 ± 1.0 seconds), US (23.3 ± 4.4 seconds), BP (46.1 ± 5.2 seconds) (P ≤ .01 FM vs US or BP). Seal burst strength and success of sealing a 5-mm carotid artery were as follows (mean ± SD mmHg, % success burst strength >240 mm Hg): FM (710 ± 206 mm Hg, 94% success), US (848 ± 565 mm Hg, 79%), and BP (619 ± 373 mm Hg, 83%).

Conclusion. Ferromagnetic heating is an effective and efficient technology for sealing and dividing of vessels. An initial prototype of the FMsealer compared favorably with commercially available products based on ultrasonic and bipolar technologies.