HEMOSTASIS OF PUNCTURED BLOOD-VESSELS USING HIGH-INTENSITY FOCUSED ULTRASOUND

The hemorrhagic complications of vascular injury can be significant. W e report on the use of high-intensity focused ultrasound (HIFU) to sto p the hemorrhage of punctured blood vessels in pigs. Two HIFU transduc ers with frequencies of 3.5 and 2.0 MHz, each equipped with a water-fi lled conical housing, were used. Major blood vessels (femoral artery a nd vein, axillary artery, carotid artery and jugular vein), 2-10 mm in diameter, of anesthetized pigs were exposed surgically and punctured with 14- and 18-gauge needles to produce moderate to profuse bleeding. Complete hemostasis was achieved in less than 3 min of HIFU treatment in most blood vessels, and all vessels were patent after the treatmen t. Both HIFU frequencies were effective in producing hemostasis. Gross examination of the HIFU-treated vessels showed a consistent hardening of the soft tissue surrounding the blood vessels, providing a seal fo r the puncture hole. Microscopic examination of the vessels showed a r emarkably localized HIFU treatment, resulting in coagulation of the ad ventitia, and an extensive fibrin network around the vessels and in th e puncture hole. The vessel walls exhibited focal swelling, without ev idence of irreversible injury. HIFU may provide a useful method for ac hieving hemostasis of punctured and traumatized blood vessels in a var iety of clinical settings. (C) 1998 World Federation for Ultrasound in Medicine & Biology.