Learning Radiology xray montage

Skull Flap Implanted in Abdominal Wall

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


  • Infection
  • Necrosis

Skull Flap from Craniectomy

Skull Flap from Craniectomy

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.

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Skull Cap in Anterior Abdominal Wall. Steven H Craig. USUHS.

Cranioplasty: why throw the bone flap out?. Flanndry T; McConnell RS. British Journal of Neurosurgery, 2001; 15(6): 518-520.