General Considerations

• On occasion, a portion of the skull may be emergently removed to relieve increased intracranial pressure (decompressive craniectomy)
• Mostly performed for acute subdural hemorrhage
• The remaining dura mater may be sewn together and the patient may wear a protective helmet
• Although other materials can be used to replace the bone flap, sometimes the patient's own skull flap is preserved for re-use
• Cosmetically, this can provide the best result
• The bone flap can be frozen, stored in sterile solutions or sewn into the subcutaneous tissue of the patient's abdomen where its viability is maintained by the body
• Advantages of storing the bone flap in the abdominal wall include sterility and continued nourishment that allows for the chondroblasts and osteoblasts to mature
• The flap is returned to the skull typically in 6-20 weeks after removal

Clinical Findings

• History of recent decompressive craniectomy or hemicraniectomy

Imaging Findings

• Absence of a portion of the skull from the cranial vault
• Presence of a bone flap in the anterior abdominal wall with the typical appearance of the inner and outer tables of the skull

Differential Diagnosis

• Ossification of a scar

Complications

• Infection
• Necrosis

Skull flap implanted in abdominal wall. There is a skull flap seen in the right anterior abdominal wall
(white arrows) on this axial and sagittally re-formatted CT of the abdomen using bone windows.
The flap was removed during a decompressive craniectomy from the right parietal region (yellow arrow)
and stored in the abdominal wall for re-implantation.
For more information, click on the link if you see this icon
For these same photos without the annotations, click here and here