Summary & Overview
CPT 61105: Skull Opening for Ventricular or Subdural Fluid Drainage
CPT code 61105 denotes a neurosurgical drainage procedure using a hand-operated twist drill to create a skull opening for withdrawal of fluid from the subdural space or cerebral ventricles. This code captures a high-acuity, often urgent intervention to relieve intracranial pressure or evacuate fluid collections, making it clinically significant across trauma, neurosurgery, and critical care settings nationally. Key payers addressed include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare.
Readers will find a concise explanation of the procedure’s clinical intent, typical sites of service, and common billing considerations. The publication provides national benchmarks where available, summarizes relevant policy or reimbursement updates that affect coverage and payment, and outlines the clinical context that drives utilization of this code, including emergency and inpatient care scenarios.
Data not available in the input for some comparative fields is noted where applicable. The piece is intended to inform billing managers, revenue cycle staff, and clinical coders about the code’s clinical definition, payer relevance, and the types of operational and policy issues to monitor.
Billing Code Overview
CPT code 61105 describes a neurosurgical procedure in which the provider uses a hand-operated twist drill to create a small opening in the skull to withdraw fluid from the subdural space or from the cerebral ventricles. This procedure is typically performed when cerebrospinal fluid or blood must be drained urgently or when intracranial pressure needs to be relieved.
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Service type: Surgical drainage procedure of the skull (skull perforation and fluid evacuation)
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Typical site of service: Hospital operating room, emergency department procedure area, or inpatient surgical suite
Clinical & Coding Specifications
Clinical Context
A typical patient is an adult or pediatric patient presenting to the emergency department or neuroscience intensive care unit with signs of increased intracranial pressure, acute subdural or epidural hematoma, intraventricular hemorrhage with hydrocephalus, or suspected intracranial infection requiring diagnostic or therapeutic cerebrospinal fluid (CSF) drainage. The care pathway frequently begins with neurological assessment, head computed tomography (CT) confirming a focal fluid collection or ventricular enlargement, and neurosurgical consultation. After informed consent, the neurosurgeon or qualified proceduralist prepares the patient using sterile technique and local anesthesia with or without conscious sedation or general anesthesia depending on clinical stability and age. The provider uses a hand-operated twist drill to create a burr hole through the skull, then advances a catheter or needle through the dura to withdraw subdural, subgaleal, or intraventricular fluid or to place an external ventricular drain as clinically indicated. Post-procedure monitoring includes neurologic checks, repeat imaging as needed, and assessment of drainage characteristics and infection risk. Typical sites of service include hospital operating rooms, emergency departments, and intensive care units. Common payors for claims include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, BUCA, and Medicare.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
22 | Increased procedural services | Use when work or time substantially exceeds typical for , well documented. |