The invention relates to the manufacture of rotary drill bits for use in drilling or coring deep holes in subsurface formations.
The invention is applicable to rotary drill bits of the kind comprising a bit body having a shank for connection to a drill string, a bit face on the bit body, a plurality of cutting structures mounted in sockets in the bit body and projecting from the face of the bit, and a number of nozzles also mounted in sockets in the bit body and communicating with a passage for supplying drilling fluid to the face of the bit.
Each cutting structure may comprise a cutting element mounted on a carrier, such as a stud or post, which is received in a socket in the bit body. One commonManagement of complex intracranial aneurysms with bypass surgery: a technique application and experience in 93 patients.
Despite advances in microsurgery and the development of new endovascular techniques, the treatment of complex intracranial aneurysms remains a daunting challenge for neurosurgeons. In the present study, we retrospectively reviewed our experience of bypass surgery in the treatment of 93 cases of complex intracranial aneurysms. A series of 93 consecutive cases of complex intracranial aneurysms were treated with bypass surgery between April 2004 and July 2013. Radial artery (RA) grafts were used in 58 cases, saphenous vein (SV) grafts in 16 cases, and occipital artery (OA) grafts in 6 cases, while the remaining 13 cases were managed with superficial temporal artery (STA) grafts. In this series, the aneurysms were excised after trapping in