[Ultrasonic skull trepanation].

Experimental ultrasonic cranial trepanation was performed on 60 albino rats by means of a semi-automatic device, Y3T-1. The trepanation is altraumatic and does not need any considerable physical effort. A histological examination showed that the zone of bone necrosis along the edge of the cut surface was one third to one half that developing with the use of electric and pneumatic surgical instruments. The Y3T-1 device was used in operations on the skull in 78 patients. Resection trepanation of the skull was carried out in 55 patients, osteoplastic in 23. With the use of the ultrasonic device the time of the operation is shorter, a good hemostatic effect is produced, and no considerable physical effort is required on the part of the surgeon. A special catch incorporated in the device ensures safety of the operation. In reimplantation of an osteoperiosteal flap or in primary-delayed cranioplasty the use of an ultrasonic chisel for punctate osteosynthesis creates good conditions for bone tissue regeneration.