An ultrasound medical treatment system includes an end effector insertable into a patient. The end effector includes a tissue-retaining device. The tissue-retaining device includes a first tissue-retaining member having an ultrasound medical-treatment transducer and includes a second tissue-retaining member. The first and second tissue-retaining members are operatively connected together to retain patient tissue between the first and second tissue-retaining members and to release patient tissue so retained. In one example, the second tissue-retaining member has an ultrasound reflector. In the same or a different example, the ultrasound medical-treatment transducer is an ultrasound imaging and medical-treatment transducer.