IntroductionUltrasonic energy is a mainstay in the armamentarium of surgeons, providing multifunctionality, precision, and control when dissecting and sealing vessels up to 5 mm in diameter. Historically, the inability to seal vessels in the 5–7 mm range has been perceived as an inherent limitation of ultrasonic technology. The purpose of this study was to evaluate sealing of vessels up to 7 mm in diameter with an ultrasonic device that modulates energy delivery during the sealing period.MethodsIn ex vivo benchtop and in vivo acute and survival preclinical models, a new ultrasonic device, Harmonic ACE®+7 Shears (Harmonic 7), was compared with advanced bipolar devices in sealing vessels 1–7 mm in diameter with respect of burst pressure, seal reliability, and seal durability. Lateral thermal damage and transection time were also evaluated.ResultsEx vivo tests of Harmonic 7 demonstrated significantly greater median burst pressures than an advanced bipolar device both for vessels <5 mm in diameter (1,078 mmHg and 836 mmHg, respectively, P=0.046) and for those in the range of 5–7 mm (1,419 mmHg and 591 mmHg, P<0.001). In vivo tests in porcine and caprine models demonstrated similar rates of hemostasis between Harmonic 7 and advanced bipolar devices, with high success rates at initial transection and seal durability of 100% after a 30-day survival period.ConclusionSealing 5–7 mm vessels is not a limitation of the type of energy used but of how energy is delivered to tissue. These studies document the ability of ultrasonic energy alone to reliably seal large vessels 5–7 mm in diameter, with significantly greater burst pressure observed in in vitro studies than those observed with an advanced bipolar technology when energy delivery is modulated during the sealing cycle. Furthermore, the seals created in 5–7 mm vessels are shown to be reliable and durable in in vivo preclinical studies.

BackgroundUltrasonic surgical devices have been demonstrated to provide excellent hemostasis, efficient transection, minimal lateral thermal damage, low smoke generation, and no risk of electrical current passage to the patient. These benefits originate from the inherent characteristics of the ultrasonic mechanism, but further improvements were thought possible through optimization of the energy delivery during application. The study reported here compared a new ultrasonic device, Harmonic ACE®+ Shears with Adaptive Tissue Technology, with a commercial predicate device, Harmonic ACE® Shears (both Ethicon Endo-Surgery, Inc., Cincinnati, OH, USA).MethodsDevices were evaluated in an in vivo porcine model intraoperatively and after a 30-day survival period. Both devices were used to seal a variety of vessels 1–5 mm in diameter, and compared for hemostasis, histological thermal damage, and adhesion formation. Sealed vessels were evaluated ex vivo for burst pressure, and visual obstruction caused by plumage from device application was assessed quantitatively.ResultsACE+ produced significantly less thermal damage, had fewer adhesions, offered faster transection, involved less visual obstruction, and had higher burst pressures than the predicate device. All vessel seals, evaluated over the course of a 30-day survival period in pigs, remained intact.ConclusionThe new Adaptive Tissue Technology algorithm assists the surgeon in achieving better control of energy delivery to the tissue, sealing vessels with supra-physiological burst pressures, and low thermal damage. These preclinical results with Harmonic ACE+ may translate into meaningful clinical benefits, providing greater precision along with more efficient and effective cutting and coagulation in open or laparoscopic procedures.

Background: Over the last two decades use of ultrasonic shears has grown in complex surgery where both precise dissection and meticulous hemostasis is required. With the introduction of HARMONIC® HD 1000i Shears (HD1000i), surgeons can now depend upon a single instrument to perform minimally-invasive dissection while securely sealing vessels up to and including 7 mm in diameter. This study was performed to compare HD1000i to the previous version of the device (HAR7) in sealing, dissecting and adhesion formation.

Background:A new ultrasonic device, Harmonic Focus ® +, has been developed that is smaller and delivers energy more efficiently than its predecessor via the inclusion of Adaptive Tissue Technology. This study was undertaken to compare its dissection capabilities to an advanced bipolar electrosurgery device in benchtop and preclinical evaluations. Methods: In ex vivo testing, Focus+ and LigaSure™ Small Jaw were evaluated for physical dimensions, device and tissue temperature after repeated applications to porcine jejunum, and burst pressure of vessel seals, transection time, and tissue sticking in 3-5 mm porcine carotid arteries. In in vivo testing, the devices were tested on intact porcine carotid arteries for thermal damage via collagen denaturation and in muscle incisions near rat sciatic nerve for acute inflammation via hematoxylin and eosin and for impaired axonal transport via β-APP. Results: Focus+ was smaller than the Small Jaw in width and height, yet it had a longer active blade and larger jaw aperture. Device temperatures were not different after application, but thermal spread (tissue temperature above 50°C) was 78% greater for Small Jaw (9.6 mm) than for Focus+ (5.4 mm). Burst pressures of sealed vessels were not significantly different between the devices: 900 (±466) mmHg for Focus+ versus 974 (±500) mmHg for Small Jaw. Small Jaw had a shorter individual transection time (5.0 seconds compared to 6.3 seconds for Focus+), whereas Focus+ had 70% less tissue sticking. Thermal damage, neural inflammation, and impaired axonal transport were all significantly lower for Focus+ compared to Small Jaw, by 19%, 57%, and 50%, respectively. Conclusion: With the addition of Adaptive Tissue Technology, Harmonic Focus+ builds upon the manifold advantages of ultrasonic devices in procedures requiring meticulous dissecting capability. Improvements in energy sensing and controlled delivery produce lower tissue temperatures and less thermal damage, especially critical when working near nerves. Focus+ produces vessel seal strengths equivalent to advanced bipolar devices and, although individual device activations are longer, the reduction in tissue sticking is expected to materially lessen operative time in clinical practice.