Minimally Invasive (Endoscopic) Sagittal Strip Craniectomy

Minimally invasive sagittal strip craniectomy is my procedure of choice for treating children with sagittal synostosis. This procedure is only an option if the patient presents to me before age 4 months of age. For patients born prematurely, this procedure is an option for the corrected age up to 4 months of age.  I prefer this procedure over open cranial vault remodeling for several reasons.

1. The growth restriction on the brain is removed earlier than open procedures which may improve development and result in better cognitive outcomes later in childhood.

2. The procedure and anesthesia time are shorter for the minimally invasive extended strip procedure (2-3 hours anesthesia time) compared to open procedures (5-6 hours anesthesia time).

3. The recovery time is shorter - a 2 day hospital stay for the minimally invasive strip procedure - compared to a 4-7 day hospital stay for open cranial vault remodeling procedures.

4. The blood transfusion rates are lower for the minimally invasive procedure - 50% or less - compared to almost 100% for open cranial vault remodeling procedures (CVR).

5. In my experience, the head shapes my patients achieve from extended sagittal strip craniectomy with postoperative helmet therapy are usually better than those achieved with open cranial vault procedures (see before and after photos)

6. There is significantly less scarring in the scalp. The incisions for strip craniectomy are only on the top of the head making them much less visible than the ear-to-ear scars required for open CVR procedures.

While good results can also be obtained from open cranial vault remodeling, I would choose the minimally invasive approach for my own child for all of the reasons listed above.

This procedure uses very small incisions - only about 1.5 inches - placed at the ends of the sagittal suture. I do not use an endoscope (long camera) in my approach because the areas of the bone cuts are easily viewed through the incisions. Through these small incisions a 2 inch wide strip of bone including the closed sagittal suture is removed. Additional wedges of bone are removed behind the coronal sutures and in front of the lambdoid sutures. These additional cuts make it easier for the parietal bones to move outward which immediately relieves constriction on the brain and allows the growth of the brain to passively reshape the skull with minimal resistance. The head shape changes appreciably while the patient is still on the operating table. Starting 10 days after the procedure a molding helmet is worn to further guide the growth of the brain to provide additional width to the skull.

Wearing a helmet after surgery does not result in any negative effects on the health of the brain. The most important role of the helmet is to allow the baby to lie on the back of the head which relieves the weight of the head from the parietal bones. This allows the parietal bones to freely remodel outward to accommodate the rapid remodeling of the brain and dura after surgery.  The brain is able to grow normally and reshape the skull in the process. Infants are able to heal large bone defects of the skull with new bone up until about 1 year of age. The areas where bone is removed in this procedure typically heals in with new bone by 3-6 months after the surgery. The figures below show the location of the bone excision in red and expected movement of the skull bones in blue and green. 

The image above shows a side view of a baby with sagittal synostosis. The locations of bone excision in a minimally invasive extended strip craniectomy are shown in RED. The blue arrow indicates how rotation of the occiput (back of head) shortens the head from front to back. 

The above image shows the top down view of the same patient's skull. Again, the central dark red area shows the wide sagittal strip craniectomy. The lighter red triangles extend down to the squamosal suture. These bone excisions allow the bone flaps to hinge on the flexible squamosal sutures and widen the skull indicated by green arrows. As the side bone flaps (parietal bones) move outward the back portion of the skull rotates up and forward like a drawbridge opening.

The typical hospital stay for my patients after this procedure is 1 day in the ICU for monitoring of neurological status and one day in a regular room prior to going home to ensure that the baby is feeding well and that pain is well controlled with oral pain medications. The baby's head shape continues to change rapidly in the first week after surgery as the brain continues to assume a normal shape, moving the overlying bone in the process. A surface scan of the head is performed 1 week after surgery from which the custom molding helmet is made. I wait one week from the time of surgery to begin helmet therapy to allow swelling to resolve and to provide time for the immediate head shape changes to stabilize. I actively participate in the design process for each patient's helmet to ensure that the helmet is customized to meet every patient's individual treatment goals. I see patients 1 week after starting to wear the helmet and every 2 weeks for 2-3 more visits to ensure that patient's head shape is changing as expected. The head shape changes rapidly after surgery requring weekly visits with the orthotist for 3-4 weeks and every 2-3 weeks thereafter.  The figures below show the typical preoperative and early postoperative changes after minimally invasive extended strip craniectomy.

My patients routinely have a normal or slightly overcorrected width to the head by 3 months after surgery. The bone excision sites usually have new bone formation by age three months. Below are example photos of several patients before and after surgery demonstrating normal or slightly overcorrected head shape by 3-4 months after minimally invasive sagittal strip craniectomy. 

There are many different approaches to sagittal strip craniectomy. My approach allows for passive reshaping of the skull shape by allowing the brain to grow without the restriction of the closed sagittal suture. Some surgeons without experience performing minimally invasive techniques will group all strip craniectomy procedures together and/or counsel patients that all strip craniectomy procedures have higher revision or complication rates compared to open procedures. There are no studies that have shown this to be true. In my experience the complications rates and revision rates after minimally invasive extended strip craniectomy are equivalent to open cranial vault remodeling procedures. The head shape changes achieved with the extended sagittal strip procedure I perform are superior to the average results of open cranial vault remodeling procedures. The minimally invasive sagittal strip gallery shows many representative patient photos demonstrating typical results obtained with this procedure. While good results can be achieved from both open cranial vault remodeling and minimally invasive techniques, it seems to make sense to choose the shorter surgery with less scarring and an easier recovery.

There are some recent studies that concluded that operating on patients with sagittal synostosis before age 6 months may result in better cognitive outcomes. Further research is needed before we can definitively conclude that earlier surgery is better, but the best evidence available suggests that surgery for sagittal synostosis at less than 6 months of age lead to better cognitive outcomes than surgery after 6 months of age. Earlier surgery also minimizes the compensatory growth at the remaining open sutures and the resulting abnormal changes in the shape of the skull. 

If the patients presents to me from age 4-5 months or older, then an open cranial vault remodeling is typically performed. There are many, many approaches to open cranial vault remodeling in sagittal synostosis. In general, the skull bones are removed in the areas of abnormal restricted and compensatory growth and repositioned to over correct the head shape. In general, for sagittal suture craniosynostosis the surgeries are aimed at restoring normal dimensions in the posterior width and height of the skull and decreasing the length of the skull from front to back. Rarely, surgeons use cranial vault distraction for sagittal synostosis. 

Open cranial vault remodeling is safe and effective, but, as stated above, has a longer recovery time, higher transfusion rate and more scarring of the scalp. That said, these procedures have an equivalent safety profile and both can produce good results when performed by experienced surgeons. Open procedures use dissolvable plates or sutures to hold the bones in their new position. Rates of palpable irregularities in the bone and cranial defects (soft spots due to absence of bone) are equivalent for open cranial vault remodeling and extended sagittal strip craniectomy.