Ultrasonic energy devices are essential for effective hemostasis during endoscopic surgery. Ultrasonic tissue transection occurs as a result of mechanical friction between the oscillating blade and the tissue. We hypothesized that blade surface structures and characteristics would affect tissue transection and sealing. The aim of this study was to clarify the efficacy of blade surface structures and characteristics in vessel sealing with an ultrasonic vibration.
We developed an ultrasonic energy device with 50-kHz vibration frequency and 50 mu m amplitude. We manufactured four types of blade surface of the ultrasonic device using microprocessing technology: (1) a non-coated blade without microgrooves, (2) a non-coated blade with microgrooves, (3) a water-repellent-coated blade without microgrooves, and (4) a water-repellent-coated blade with microgrooves. We compared the performance of the four devices and a commercially available ultrasonic device with a non-coated blade without microgrooves in an ex vivo vessel-sealing experiment. We sealed porcine carotid arteries (3-5 mm diameter) using each device 20 times.
The cutting time of the water-repellent-coated blade with microgrooves was the shortest (11.0 +/- 3.4 s); however, it did not differ significantly from that of the commercial ultrasonic device (12.9 +/- 2.9 s, p = 0.73). The burst pressure of the water-repellent-coated blade without microgrooves (1456 +/- 425 mmHg) was significantly higher than that of the commercial ultrasonic device (966 +/- 559 mmHg, p = 0.04). The sealing failure rate of the water-repellent blade with microgrooves was the lowest of all devices (0 %). Instrumental sticking of tissue decreased in the water-repellent devices. The sealing width was not significantly different.
The surface-processing of microgrooves and water-repellent coatings will improve the potential of ultrasonic devices with a fast transection and a high sealing reliability.