What is the operative technique for a bilateral burr hole (cranial decompression procedure) craniostomy?

Bilateral Burr Hole Craniostomy Operative Technique

For bilateral burr hole craniostomy, place burr holes at the pre-coronal suture entry point (1 cm anterior to the coronal suture at the level of the superior temporal line) bilaterally, followed by closed-system drainage for 2-4 days postoperatively. 1, 2

Patient Positioning and Preparation

• Position the patient supine with the head elevated 30 degrees to facilitate venous drainage 1
• Prepare and drape the bilateral frontal-parietal regions in standard sterile fashion
• Mark the pre-coronal suture entry points bilaterally: 1 cm anterior to the coronal suture at the level of the superior temporal line 1

Burr Hole Placement Strategy

The pre-coronal suture entry point is the optimal location for bilateral burr holes, as this approach successfully drains the majority (79.1%) of chronic subdural hematomas and is particularly useful for bilateral cases. 1

• For standard bilateral burr hole craniostomy, create burr holes 12-30 mm in diameter at the marked pre-coronal entry points 2
• This location provides optimal access to the subdural space while avoiding critical neurovascular structures 1
• Ensure adequate hematoma thickness on preoperative CT imaging before proceeding with burr hole technique (minimum thickness required for safe drainage) 1

Surgical Technique

Incision and Exposure

• Make bilateral linear skin incisions (approximately 3-4 cm) centered over each marked entry point
• Use strong retraction with hooks to maintain a clean operative field 3, 4
• Consider hemostatic clips at wound edges to minimize bleeding 4

Burr Hole Creation

• Create the burr hole over the marked entry point using a perforator drill
• The burr hole size should range from 12-30 mm in diameter 2
• For craniotomies requiring larger exposure, a single centrally-placed burr hole can accommodate craniotomies up to 9 cm in diameter, while larger craniotomies (>9 cm) require two strategically placed burr holes 5

Dural Management

• Carefully separate the dura from the inner table using blunt dissectors under direct visualization 3, 4
• In elderly patients with adherent dura, use a long blunt flexible dissector to minimize risk of dural tear 3
• Open the dura in a cruciate fashion after achieving adequate hemostasis 2

Drainage System

• Insert closed-system drainage catheters through both burr holes into the subdural space 2
• Maintain drainage for 2-4 days postoperatively 2
• This closed-system approach is the method of choice for initial treatment, even when neomembranes are detected on preoperative contrast-enhanced CT or MRI 2

Technical Considerations for Specific Scenarios

Bilateral Hematomas

• The pre-coronal entry point technique is especially useful for bilateral hematomas, allowing simultaneous bilateral drainage 1
• All bilateral cases in one series were successfully treated using this approach 1

Elderly Patients

• This technique is particularly advantageous in elderly patients due to its minimally invasive nature 1
• Use extra caution with dural separation in elderly patients due to increased dural adherence 3

Expected Outcomes and Reoperation Rates

• Burr hole craniostomy achieves good clinical outcomes with 72.3% of patients having no or only mild neurologic deficits at discharge 2
• Reoperation rate is approximately 18.5% after burr hole craniostomy, typically due to rebleeding (6 cases), residual subdural fluid (4 cases), or residual thick hematoma membranes (8 cases) 2
• Neither morbidity nor mortality is significantly associated with the burr hole technique when performed appropriately 1

When to Convert to Craniotomy

Reserve craniotomy for cases with reaccumulating hematoma or residual hematoma membranes that prevent brain reexpansion after initial burr hole drainage. 2

• Only 7% of cases have insufficient hematoma thickness on CT to perform burr hole craniostomy and require primary craniotomy 1
• If burr hole drainage fails (approximately 2% of cases), convert to burr hole craniostomy at the parietal location or formal craniotomy 1

Postoperative Management

• Maintain closed-system drainage for 2-4 days 2
• Monitor neurological status closely for signs of reaccumulation or inadequate drainage 2
• Follow-up imaging to confirm adequate hematoma evacuation and brain reexpansion 2