Sealing vessels up to 7 mm in diameter solely with ultrasonic technology

Abstract

Introduction: Ultrasonic 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.

Methods: In 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.

Results: Ex 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.

Conclusion: Sealing 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.

Keywords: 7 mm; Harmonic; burst pressure; ultrasonic; vessel sealing.

Figure 1

Handle of the Harmonic ACE^®+7 with advanced hemostasis button (green). Note: Harmonic ACE+7 (Ethicon Inc., Cincinnati, OH, USA).

Figure 2

Burst pressures at decreasing power level settings for 5–7 mm porcine carotid arteries. The advanced hemostasis (AH) power level setting utilizes modulated energy output. Error bars represent two standard errors.

Figure 3

Burst pressures for Harmonic ACE^®+7 and LigaSure™ for 3–5 mm and 5–7 mm vessels. For 3–5 mm vessels. Notes: Harmonic ACE+7 (Ethicon Inc., Cincinnati, OH, USA) was used in both power level 3 and advanced hemostasis modes. Error bars represent the standard error of the mean. Ligasure (Covidien, Mansfield, MA, USA). Abbreviations: HAR7, Harmonic ACE+7; PL3, power level 3; AH, advanced hemostasis.

Figure 4

Event occurrences (leaks at transection, adventitial leaks, bursts under pressure) for 3–5 mm and 5–7 mm vessels. For 3–5 mm vessels. Note: Harmonic ACE^®+7 (Ethicon Inc., Cincinnati, OH, USA) was tested in both power level 3 and advanced hemostasis modes. LigaSure (Covidien, Mansfield, MA, USA). Abbreviations: HAR7, Harmonic ACE+7; PL3, power level 3; AH, advanced hemostasis.

Figure 5

Mode of failure (recannulation [Recannul], leak at transection, recannulation at pressurization [Recann at P], adventitial leak, burst upon pressurization) as a function of sealing time or full transection for 5–7 mm porcine carotid arteries.

Figure 6

Hematoxylin and eosin staining of goat carotid artery sealed with Harmonic ACE^®+7 at 40× magnification. Notes: Black lines show the extent of collagen denaturation. Harmonic ACE+7 (Ethicon Inc., Cincinnati, OH, USA).

Figure 7

Hematoxylin and eosin staining of goat carotid artery sealed with LigaSure™ at 40× magnification. Notes: Black lines show the extent of collagen denaturation. Ligasure (Covidien, Mansfield, MA, USA).

Figure 8

Three phases of vessel sealing are modulated based on predictive analytics to produce optimal seals for the tissue conditions encountered.