How should the Cavitational Ultrasonic Surgical Aspirator (CUSA) be used as a power control device for liver resection?

CUSA Power Control Settings for Liver Resection

Set the CUSA amplitude to 10-20% power for optimal liver parenchymal dissection, which allows selective fragmentation of hepatocytes while preserving vascular and biliary structures. 1

Power Settings and Technique

• Use reduced amplitude (10-20%) for standard hepatic parenchymal dissection to selectively fragment liver tissue while minimizing damage to Glissonean cords and hepatic veins 1

• The CUSA functions through ultrasonic vibration at the tip that selectively fragments tissue, with simultaneous saline irrigation and aspiration of fragmented tissue 2, 1

• The device should be used in an "excavation" technique, similar to archaeological excavation, where buried vascular structures are exposed intact without injury 2

Hemodynamic Control During CUSA Use

• Maintain low central venous pressure (below 5 cm H2O) during hepatic transection to minimize blood loss while using CUSA 3

• The Pringle maneuver for inflow control can be avoided when using CUSA with proper technique, reducing ischemic stress to the remnant liver 4

• Combine CUSA with bipolar cautery (set at 50 watts) equipped with saline dripping (approximately one drop per second) for immediate hemostasis of small vessels after sonicating parenchymal cells 4

Clinical Outcomes

• CUSA use significantly reduces operative blood loss compared to traditional digitoclasia techniques, with average bleeding of 685 cc for lobectomies and 540 cc for segmentectomies 5

• Duration of hepatic transection is significantly reduced (mean 28 minutes for lobectomies, 22 minutes for segmentectomies) with statistically significant reduction in operative time (p < 0.01) 5, 6

• Postoperative complications are notably reduced compared to conventional techniques 5, 6

Specific Dissection Technique

• After sonicating parenchymal cells at reduced amplitude, small branches of Glisson's tree and hepatic vein tributaries become exposed 4

• Coagulate exposed vascular structures with bipolar cautery before cutting with scissors to maintain hemostasis 4

• The technique allows dissection in consideration of tissue layers, surfaces, and membranes while minimizing bleeding 1

Fluid Management Context

• Use balanced crystalloids (e.g., Ringer's lactate) as maintenance fluid during CUSA-assisted resection 3

• Consider stroke volume variation (SVV)-guided goal-directed fluid therapy rather than CVP monitoring alone to optimize cardiac output during the procedure 3