Abstract: Methods and apparatus for enabling substantially bloodless surgery and for stemming hemorrhaging. High intensity focused ultrasound (“HIFU”) is used to form cauterized tissue regions prior to surgical incision, for example, forming a cauterized tissue shell around a tumor to be removed. The procedure is referred to as “presurgical volume cauterization.” In one embodiment, the method is particularly effective for use in surgical lesion removal or resection of tissue having a highly vascularized constitution, such as the liver or spleen, and thus a propensity for hemorrhaging. In further embodiments, methods and apparatus for hemostasis using HIFU is useful in both surgical, presurgical, and medical emergency situations. In an apparatus embodiment, a telescoping, acoustic coupler is provided such that depth of focus of the HIFU energy is controllable. In other embodiments, apparatus characterized by portability are demonstrated, useful for emergency medical situations.