Minimally invasive bedside craniotomy using a self-controlling pre-adjustable mechanical twist drill trephine

Surg Neurol. 1998 Sep;50(3):226-9; discussion 229-30. doi: 10.1016/s0090-3019(97)00456-4.


Background: Craniotomy with a mechanical twist drill is a standard, minimally invasive procedure in neurosurgery, widely used for the drainage of chronic subdural hematomas and the placement of ventricular drains. Nevertheless, the use of a standard twist drill trephine bears the risk of causing cerebral lesions.

Method: A commercially available mechanical twist drill system has been modified by a special self-controlling drill and a pre-adjustable distance holder that limits intracerebral penetration. After initial cadaver testing, the modified trephine has been used for 65 trephinations in patients (37 chronic subdural hematomas, 21 external ventricular drains, 6 frontal hygromas, 1 tumor cyst).

Results: There were no complications related to the modified trephine; cerebral lesions caused by drilling too deeply or by uncontrolled penetration were safely prevented. In our series no procedure related infections occurred, and the drilling time was reduced significantly.

Conclusion: The described modified mechanical twist drill enables fast, easy, and safe craniotomy without jeopardizing the advantages of a mechanical twist drill. Therefore, it can be recommended particularly for difficult emergency conditions.

MeSH terms

  • Brain Injuries / etiology
  • Brain Injuries / prevention & control*
  • Craniotomy / adverse effects
  • Craniotomy / instrumentation*
  • Craniotomy / methods
  • Equipment Design
  • Humans
  • Mechanics
  • Minimally Invasive Surgical Procedures
  • Surgical Instruments*
  • Treatment Outcome
  • Trephining / adverse effects
  • Trephining / instrumentation*
  • Trephining / methods