burr hole

DEFINITION of burr hole

burr hole is a small, circular opening created through the full thickness of the calvarium using a mechanical or powered perforator, allowing surgical access to the intracranial compartments without the wider bone removal required for a craniotomy or craniectomy. It is distinguished from a twist drill hole, a narrower access point made with a hand-held drill bit for less invasive punctures or catheter placement, and from a craniotomy, in which a bone flap is elevated and later replaced. The procedure works by penetrating the outer table, diploë, and inner table of the skull to expose the dura, permitting evacuation of blood or fluid collections, biopsy of tissue, or insertion of monitoring/drainage devices. Unlike many medterms, burr hole has no physiologic (non-therapeutic) counterpart — every burr hole is performed for a pathological indication, most commonly hematoma evacuation, hydrocephalus management, or intracranial abscess drainage. Clinically relevant subtypes coded separately include the exploratory burr hole (61250, 61253), the burr hole for hematoma evacuation (61154, 61156), and the burr hole for device implantation (61210). Burr hole is most often confused with craniotomy, which involves a much larger bone flap for wide surgical exposure, and with twist drill hole, which is a narrower, often bedside procedure using a hand drill rather than a formal perforator.

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ETYMOLOGY of burr hole

english

Component	Origin	Meaning
burr	Middle English burre, of uncertain (possibly Old Norse or Old French) origin	Originally “a rough, prickly seed case or the rough edge left by cutting”; extended by the 19th century to name the rotary, abrasive cutting tip of a surgical or dental drill
hole	Old English hol (“hollow, cave, orifice”), from Proto-Germanic *hulan	”An opening or perforation through a surface”
trypan- (related term)	Greek τρύπανον (trýpanon), from trypan (“to bore, pierce”)	“Borer, auger” — root of the historically related term trephine

The compound term burr hole entered surgical usage in the 1800s, describing the small opening left by a mechanical bone drill or “burr.” It largely displaced the older term trephination (from French trépan, from Latin trepanum, from Greek trypanon, “borer”) in everyday operative language, though trephination and trepanation remain standard clinical synonyms, and skull trepanation is documented archaeologically as one of the oldest known surgical practices. The Greek root trypan- (“to bore”) ultimately traces to the Proto-Indo-European root terh₁- (“to rub, turn, bore”), tying burr hole terminology to the instrument name trephine and the verb “to trephine.” The combining form cran- (“skull”) appears in the related procedural family craniotomy and craniectomy, which share the goal of cranial access but differ from burr hole in the extent of bone removal.

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🔀 ALIASES / ALTERNATE TERMS

• Burr-hole (adjective form — “burr-hole craniostomy,” “burr-hole evacuation,” “burr-hole trephination”)
• Bur hole (alternate single-r spelling used interchangeably in surgical literature and some CPT descriptor sources)
• Trephination (clinical synonym for the modern surgical creation of a cranial opening; often used interchangeably with burr hole)
• Trepanation (historical/anthropological term for the same act of drilling into the skull, dating to prehistoric surgical practice)
• Craniostomy (clinical synonym emphasizing creation of a small cranial opening, as opposed to craniotomy or craniectomy)
• Twist drill hole (narrower variant made with a hand-held twist drill for bedside or less invasive access; CPT 61105-61108)
• Exploratory burr hole (diagnostic burr hole not followed by other surgery; CPT 61250, 61253)
• Stereotactic burr hole (access point for stereotactic biopsy, aspiration, or excision of an intracranial lesion; CPT 61750, 61751)

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🔗 RELATED TERMS

• Craniotomy — the larger-scale counterpart to burr hole; a bone flap is elevated for wide exposure and later replaced, unlike the small, permanent opening of a burr hole
• Craniectomy — bone flap is removed and not replaced (e.g., decompressive craniectomy); distinguished from burr hole by the extent and permanence of bone removal
• Trephine — the handheld or powered surgical instrument used to create a burr hole; also used as a verb, “to trephine”
• Twist drill — smaller, often bedside instrument creating a narrower access hole than a formal burr hole perforator
• Subdural hematoma — the most common indication for emergent burr hole evacuation; traumatic form coded S06.5X0A-S06.5X9A, nontraumatic form coded I62.00-I62.03
• Epidural (extradural) hematoma — second major traumatic indication for burr hole evacuation; coded S06.4X0A-S06.4X9A
• Hydrocephalus — indication for burr hole placement of a ventricular catheter or external ventricular drain; coded G91.0-G91.9
• Intracranial abscess — indication for burr hole drainage or aspiration; coded G06.0
• External ventricular drain (EVD) — CSF diversion/ICP-monitoring device placed through a burr hole
• Stereotactic biopsy — tissue-sampling procedure frequently performed through a burr hole access point

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CODING CORNER

🏥 ICD-10-CM CODES (Common Indications for Burr Hole Procedures)

Traumatic Subdural Hemorrhage (S06.5X-, Initial Encounter — LOC Duration Required)

Code	Description
S06.5X0A	Traumatic subdural hemorrhage without loss of consciousness, initial encounter
S06.5X1A	Traumatic subdural hemorrhage with loss of consciousness of 30 minutes or less, initial encounter
S06.5X4A	Traumatic subdural hemorrhage with loss of consciousness of 6-24 hours, initial encounter
S06.5X9A	Traumatic subdural hemorrhage with loss of consciousness of unspecified duration, initial encounter

Nontraumatic Subdural Hemorrhage (I62.0- — Acuity Required)

Code	Description
I62.00	Nontraumatic subdural hemorrhage, unspecified
I62.01	Nontraumatic acute subdural hemorrhage
I62.02	Nontraumatic subacute subdural hemorrhage
I62.03	Nontraumatic chronic subdural hemorrhage

Traumatic Epidural (Extradural) Hemorrhage (S06.4X-, Initial Encounter)

Code	Description
S06.4X0A	Epidural hemorrhage without loss of consciousness, initial encounter
S06.4X1A	Epidural hemorrhage with loss of consciousness of 30 minutes or less, initial encounter
S06.4X9A	Epidural hemorrhage with loss of consciousness of unspecified duration, initial encounter

Hydrocephalus (G91.-)

Code	Description
G91.0	Communicating hydrocephalus
G91.1	Obstructive hydrocephalus
G91.2	(Idiopathic) normal pressure hydrocephalus
G91.3	Post-traumatic hydrocephalus, unspecified
G91.9	Hydrocephalus, unspecified

Intracranial Abscess

Code	Description
G06.0	Intracranial abscess and granuloma

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🔧 COMMON CPT CODES (Burr Hole-Related Procedures)

CPT Code	Description
61105	Twist drill hole for subdural or ventricular puncture
61107	Twist drill hole for subdural, intracerebral, or ventricular puncture; for implanting ventricular catheter, reservoir, EEG electrode(s), pressure recording device, or other cerebral monitoring device
61108	Twist drill hole(s) for subdural, intracerebral, or ventricular puncture; for evacuation and/or drainage of hematoma or fluid collection
61120	Burr hole(s) for ventricular puncture (including injection of gas, contrast media, dye, or radioactive material)
61140	Burr hole(s) or trephine; with biopsy of brain or intracranial lesion
61150	Burr hole(s) or trephine; with drainage of brain abscess or cyst
61151	Burr hole(s) or trephine; with subsequent tapping (aspiration) of intracranial abscess or cyst
61154	Burr hole(s) with evacuation and/or drainage of hematoma, extradural or subdural
61156	Burr hole(s); with aspiration of hematoma or cyst, intracerebral
61210	Burr hole(s); for implanting ventricular catheter, reservoir, EEG electrode(s), pressure recording device, or other cerebral monitoring device (separate procedure)
61250	Burr hole(s), exploratory, not followed by other surgery; supratentorial, unilateral or bilateral
61253	Burr hole(s), exploratory, not followed by other surgery; infratentorial, unilateral or bilateral

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⚠️ Coding Note: For traumatic subdural (S06.5X-) and epidural (S06.4X-) hemorrhages, the 7th-character extension requires documented loss-of-consciousness duration — query if the operative or ED note only states “SDH” without LOC timing, since defaulting to “unspecified duration” understates severity capture. For nontraumatic subdural hemorrhage (I62.0-), acuity (acute/subacute/chronic) is frequently under-documented; “chronic subdural hematoma” evacuated via burr hole is one of the most commonly undercoded diagnoses on inpatient profee neurosurgery claims when providers write only “SDH” — this affects both code specificity and MS-DRG severity weighting. Sequence the underlying condition (hematoma, hydrocephalus, abscess) as the diagnosis driving the encounter; the CPT burr hole code is reported separately as the procedure. 61210 is a “separate procedure” code — do not report it in addition to 61140, 61150, 61151, 61154, or 61156 when device implantation occurs through the same burr hole at the same session. Append modifier -50 for bilateral burr holes (e.g., bilateral chronic SDH evacuation), per Medicare and most commercial payer guidance. Watch for family confusion between the 612xx cranial burr hole codes and the unrelated 632xx spinal laminectomy/AVM family — a common transcription error on op note abstraction.

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DERIVATIONS of burr hole

TABLE definition AS Definition
FROM #medterm 
WHERE length(filter(roots, (word) => econtains([[burr hole]].roots, word))) > 0 AND file.name != [[burr hole]].file.name
SORT file.name ASC

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Query functionality

TABLE definition AS Definition
FROM #medterm 
WHERE length(filter(definition, (word) => econtains([[burr hole]].definition, word))) > 0 AND file.name != [[burr hole]].file.name

Med terms dictionary Appendix A Prefixes Appendix B Combining Forms Appendix C Suffixes Appendix D Suffix forms