Minimally Invasive Surgery for Sagittal Synostosis
Sagittal synostosis is the most common form of craniosynostosis and represents 40-50% of cases of nonsyndromic suture closure. Craniosynostosis results from an absence or premature closure of one or more of the cranial sutures in between the developing bones of the skull. Typically when a suture is closed it can be identified at birth and creates a very stereotypical head shape.
Children with sagittal synostosis are born with very narrow and elongated head shapes. The forehead tends to protrude forward and the back of the head is very narrow and sometimes pointed. This head shape is called scaphocephaly or dolicocephaly. If the deformity is not corrected the head shape will continue to progress with significant long term consequences and potential increased intracranial pressure.
If the disorder is recognized early in life surgical correction can be much simpler than when the diagnosis is delayed. Correction can be performed later in life (after 6 months of age) but requires extensive reconstruction of the skull. When identified early, surgery can be done around 3 months of age and a minimally invasive approach can be used. Traditional early approaches to correction involved removing the suture called a “strip” craniectomy. This approach involved a large incision to adequately expose the suture and provide visualization of the sagittal sinus which lies directly under the involved suture. Simply removing the suture however has a high rate of recurrence. Expansion of this simple procedure to include “barrel staving” the parietal bones has reduced the rate of recurrence and provides immediate improvement of the head shape with excellent long term results and virtually no complications.
New procedures involving the use of endoscopes have been developed with decreased blood loss and smaller incisions. Criticism of this approach has resulted because of the limited exposure and limited surgery increasing the risk for vascular injury and requiring the child to wear a helmet for up to a year after surgery. As well, the surgery requires two incisions, one of which is fairly anterior on the skull at the anterior fontanelle and may be visible later in life.
Now, at RMHC, we have developed a new procedure using an endoscopic approach that addresses these criticisms. A single incision along the posterior vertex is made approximately 7 cm wide, less than 1/3 of the traditional incision and similar to the sum of the incisions used for the typical endoscopic surgery. Using endoscopes and special retractors a 3 cm strip over the sagittal ridge is removed. With this approach, the posterior aspect of the sagittal sinus is able to be visualized directly to avoid injury and preserve bridging veins. A bone cutting scissors is then used to barrel stave the parietal bones and allows extension across the coronal sutures as well. Because extensive remodeling can be performed through this incision, no helmet is required after surgery.
The initial case was performed in January of this year at RMHC. The cosmetic improvement was dramatic immediately after surgery. The surgery itself took approximately 50 minutes and proceeded without difficutly. Within the first few days of surgery, there was a measurable 3 cm decrease in the distance between the anterior and posterior fontanelles demonstrating the rapid improvement in the scaphocephaly. The child did very well and was discharged 2 days after surgery without complication.
This minimally invasive endoscopic approach shows promise in reducing the impact of these corrective surgeries on children with these disorders. Early recognition of craniosynostosis and referral for treatment remains key in optimizing the treatment and outcome for these babies.
Traditional incision extends from ear to ear in a bicoronal fashion (left). Typical endoscopic approach involves anterior and posterior incisions (right). The new procedure described here uses a single incision on the vertex (right) and allows direct visualization of the posterior sagittal sinus.
Pre and post op imaging demonstrating scaphocephaly and immediate improvement at the 3 week post op visit.