Occlusion of canine atrial appendage using an expandable silicone band.

Objective: Because the left atrial appendage is thought to be a major source of stroke in patients with atrial fibrillation, a new device and technique were developed for thoracoscopic isolation of the left atrial appendage.

Methods: The left and right atrial appendages were approached from an 11.5-mm port in the left thorax in 15 canines.

Band occlusion of the atrial appendage.

Objectives: A new device has been developed for occlusion of the left atrial appendage (LAA). Previous investigations have been in the canine model. The canine atrial appendage does not vary in size and shape as much as the human.

Effects of high-intensity focused ultrasound on nerve conduction.

The effects of various exposures (intensity, duration) of high-intensity focused ultrasound (HIFU) on sciatic nerve conduction were investigated in vivo in rats. The objective was to identify HIFU exposures that produce biological effects ranging from partial to complete conduction block, indicating potential use of HIFU as an alternative to current clinical methods of inducing nerve conduction block. In the study, 26 nerves were exposed and treated with 5-s applications of 5.

Resection of abdominal solid organs using high-intensity focused ultrasound.

Our objective was to evaluate high-intensity focused ultrasound (HIFU) for minimizing blood loss during surgery by hemodynamically isolating large portions of solid organs before their resection. A high-power HIFU device (in situ intensity of 9000 W/cm(2), frequency of 3.3 MHz) was used to produce a wall of cautery for sealing of blood vessels along the resection line in surgically exposed solid organs (liver lobes, spleen and kidneys) of eight adult pigs.

Image-guided high-intensity focused ultrasound for conduction block of peripheral nerves.

The objective of our work has been to investigate the use of ultrasound image-guided high-intensity focused ultrasound (HIFU) to non-invasively produce conduction block in rabbit sciatic nerves in vivo, a technique that could become a treatment of spasticity and pain. The work reported here involved the investigation of the duration of such conduction blocks after HIFU treatment and whether they resulted in axon degeneration. The right sciatic nerves of 12 rabbits were treated, under guidance of ultrasound imaging, with repeated 5-s applications of 3.

Image-guided HIFU neurolysis of peripheral nerves to treat spasticity and pain.

Spasticity, a major complication of central nervous system disorders, signified by uncontrollable muscle contractions, is very difficult to treat effectively. We report on the use of ultrasound (US) image-guided high-intensity focused US (HIFU) to target and suppress the function of the sciatic nerve complex of rabbits in vivo, as a possible treatment of spasticity. The image-guided HIFU device included a 3.