An ultrasonic dissection and coagulation system for surgical use is provided. The system includes an ultrasonic instrument, a control module, and a remote actuator. The ultrasonic instrument has a housing and an elongated body portion extending from the housing. An ultrasonic transducer supported within the housing is operatively connected to a cutting jaw by a vibration coupler. The vibration coupler conducts high frequency vibration from the ultrasonic transducer to the cutting jaw. A trocar assembly including a cannula may be provided to slidably receive the elongated portion of the ultrasonic instrument.