Supratentorial Craniotomy Using a Threadwire Saw -Technical Note-

Abstract

An alternative technique for cutting the bone flap in supratentorial craniotomy uses a threadwire saw (T-saw), originally developed for spinal surgery. After placing a burr hole at each corner of the intended craniotomy, osteotomy is performed between adjacent burr holes using a craniotome, leaving a bony bridge of approximately 1/3 of the length of the osteotomy. The T-saw is introduced between adjacent burr holes through the epidural space and the bridge is cut with reciprocating strokes. The narrow beveled cut reduces the bone gap for fitted bone flap fixation. On closure, the bridge firmly supports the flap and only sutures are needed for fixation. A minimal amount of filler is required to fill the bone gap. Successful bone flap fixation was obtained in more than 100 cases. No technique-related complications such as dural laceration or flap displacement occurred. Osteotomy using a T-saw was somewhat timeconsuming, but cutting efficiency was improved with a Diamond T-saw, featuring a section of cable covered with diamond particles. This method is ideal for bone cuts in cosmetic cranioplasty; is easy and safe to perform, is inexpensive, and avoids the need for flap fixation with metal devices.

Safe fronto-orbito-zygomatic osteotomy using a diamond-coated threadwire saw in orbito-zygomatic craniotomy

“…The original procedures used sectioning into the SOF and IOF to create the FOZ bar in order to reduce bony loss. [ 6 ] However, sectioning into the SOF carries the potential risk of injury to the cranial nerves passing through the foramen. The necessary extent of bony removal depends on the pathology.…”

Repositioning of Cranial Bone Flaps Cut with a Diamond-Coated Threadwire Saw: 5-Year Experience with Cosmetic Cranioplasty without Fixation Devices

“…We found that the T-saw, developed by Japanese orthopedic surgeons in 1996, 13 was appropriate for this purpose. 6 It was subsequently introduced in spinal surgery, for example, cervical spine laminoplasty to split the spinous process in the midline with minimal bone gaps and its use has continued to increase. 14,15 The saw features a soft, flexible, disposable stainless-steel microcable measuring 80 cm in length and 0.36 (small), 0.54 (medium), or 0.81 mm (large) in diameter.…”

“…To address these issues, we developed an alternative technique for supratentorial craniotomy that involves the use of a threadwire saw (T-saw). 6 The minimum bone gap in the cut line is less than 1 mm; this avoids bone flap depression without requiring support by artificial fixation systems. Here we present our 5-year experience with an improved T-saw (diamond T-saw) (Mani Inc., Utsunomiya, Japan), report outcomes, and provide additional tips.…”

Use of Bioabsorbable Plates for Cranial Fixation -Technical Note-

“…4,8,10) These techniques are also cost effective, provide high fixation strength, and do not affect postoperative radiographic imaging. However, these procedures are somewhat complex, and require skill and experience.…”