61107

Twist Drill Hole for Subdural or Ventricular Puncture for Monitoring

CPT code 61107 describes a neurosurgical procedure where a small-diameter hole is created in the cranium using a manual or electric twist drill. This technique is specifically utilized for the placement of various intracranial devices, such as ventricular catheters (extraventricular drains or EVDs), pressure transducers (e.g., Camino or Codman bolts), or brain tissue oxygen monitoring probes (e.g., Licox). Unlike a burr hole (code 61210), which involves a larger diameter and is usually performed with a high-speed power drill or a perforator in an operating room, a twist drill hole is frequently performed at the bedside, particularly in emergency or intensive care settings where rapid access to the intracranial compartment is necessary for life-saving monitoring or decompression. The procedure involves identifying a precise anatomical landmark, most commonly Kocher’s point, which is situated approximately 11 centimeters posterior to the glabella and 2 to 3 centimeters lateral to the mid-sagittal suture, typically on the non-dominant hemisphere to avoid eloquent brain regions. This location helps the surgeon avoid the primary motor cortex and the superior sagittal sinus. After local anesthesia is administered, the surgeon makes a small stab incision in the scalp, applies the twist drill to penetrate both the outer and inner tables of the skull, and then punctures the dura mater. Once the skull is breached, the monitoring device or catheter is advanced into either the subdural space or the lateral ventricle. This allows for the continuous monitoring of intracranial pressure (ICP), which is vital in managing patients with severe traumatic brain injury, large intracranial hemorrhages, or acute hydrocephalus. The clinician can also drain cerebrospinal fluid (CSF) to manage elevated pressure if a ventricular catheter is used. Accurate placement is essential to minimize risks such as intracerebral hemorrhage, infection (ventriculitis), or misplacement of the probe.

Clinical Indications

  • Traumatic brain injury (TBI) with suspected or confirmed intracranial hypertension
  • Aneurysmal subarachnoid hemorrhage (aSAH) requiring ICP monitoring or CSF diversion
  • Acute obstructive hydrocephalus
  • Intracerebral hemorrhage with intraventricular extension
  • Monitoring of brain tissue oxygenation in comatose patients
  • Assessment of idiopathic intracranial hypertension (pseudotumor cerebri) in select cases
  • Management of acute-on-chronic subdural hematomas requiring drainage

Procedure Steps

  1. Identify and mark the entry site, typically Kocher's point (11 cm posterior to glabella, 2-3 cm lateral to midline).
  2. Sterilize the scalp area and drape in a sterile fashion.
  3. Inject local anesthetic (e.g., 1% lidocaine with epinephrine) into the scalp and down to the periosteum.
  4. Perform a small (approx. 1 cm) skin incision using a scalpel.
  5. Apply the twist drill perpendicular to the skull surface and drill through the outer and inner cortical tables.
  6. Feel for the 'give' or 'drop' indicating the drill has successfully penetrated the inner table.
  7. Puncture the dura mater using a dural needle or the drill bit tip if appropriate.
  8. Insert the ventricular catheter or monitoring probe through the drill hole into the desired depth (typically 5-7 cm for ventricular access).
  9. Confirm placement by observing CSF flow (if ventricular) or checking the waveform on the monitoring system.
  10. Secure the device to the scalp using sutures and apply a sterile dressing.

Coding Guidelines

  • CPT 61107 is for the initial placement of the device; do not report for simple maintenance or adjustments.
  • If a burr hole is used instead of a twist drill, see code 61210.
  • Imaging guidance, such as CT (77011) or ultrasound (76942), may be reported separately if performed and documented, unless specifically bundled by the payer.
  • This code includes the creation of the hole and the placement of the catheter or monitoring device.
  • For the removal of the device, if performed by the same surgeon during the global period, it is typically considered part of the initial procedure unless it requires a return to the operating room.
  • Do not report 61107 in conjunction with 61210 or other craniotomy codes at the same anatomical site during the same session.

Associated ICD-10 Codes