Cranial vault remodeling is the gold-standard treatment for craniosynostosis, a condition characterized by premature fusing of the bones in the skull. At Gillette Children’s Specialty Healthcare, Robert Wood, MD, Associate Medical Director for Craniofacial Services and pediatric craniofacial and plastic surgeon, has pioneered a novel blood management protocol that greatly reduces the need for perioperative blood transfusions.
During typical development, the fibrous bands of tissue, known as sutures, that separate the six bones of the cranial vault remain flexible until the second or third year of life. In the case of craniosynostosis, however, one or more of the cranial sutures fuses before birth. As a result, brain and skull growth is inhibited, which can cause physical deformity and elevated intracranial pressure.
A Complex Presentation
Abnormal head shape is the most common indicator of craniosynostosis, which is typically diagnosed at birth or during the first few months of life. The altered head shape and degree of deformity present is pathognomonic for the suture vault affected.
Approximately 50 percent of craniosynostosis cases arise from premature fusion of the sagittal suture — the midline suture that runs from the front to the back of the skull and separates the parietal bones. Babies with this type of craniosynostosis, which is known as scaphocephaly, present with a long, narrow head shape.
Fusion of the coronal suture and of the metopic and lambdoid sutures can also occur. Anterior plagiocephaly is due to unilateral fusion of the coronal suture — the suture that separates the frontal and parietal bones — while brachycephaly arises from bilateral fusion of the coronal suture. Babies with anterior plagiocephaly or brachycephaly often have noticeable flatness on one or both sides of their forehead. Fusion of the metopic suture — the suture that separates the frontal bones — is known as trigonocephaly and may give rise to a triangular head shape. Finally, fusion of the lambdoid suture separating the occipital and parietal bones can cause posterior plagiocephaly, which may lead to flattening on one side of the back of the skull.
Robert Wood, MD, Associate Medical Director for Craniofacial Services and pediatric craniofacial and plastic surgeon with Gillette Children’s Specialty Healthcare
“At Gillette Children’s Specialty Healthcare, we have transformed what was formerly a life-threatening procedure into a routine operation that is no longer a defining factor in a child’s life. When children go to kindergarten, our gold standard is that they’re not detectable by their peers at a conversational distance as having had craniosynostosis or surgery. I think that’s really important, and that’s not a ‘home run’ for us — that’s an average procedure.”
— Robert Wood, MD, Associate Medical Director for Craniofacial Services and pediatric craniofacial and plastic surgeon at Gillette Children’s Specialty Healthcare
Multiple-suture craniosynostosis is typically more severe than single-suture craniosynostosis and is usually associated with a genetic syndrome such as Apert syndrome. In the case of Apert syndrome, for example, multiple-suture craniosynostosis may present concurrently with other deformities, including fused fingers and toes, cleft palate, hearing loss and cervical vertebrae fusion.
Creating the Treatment Plan
While most children with craniosynostosis require surgery, a small subset of patients with mild trigonocephaly may not. To determine if cranial vault remodeling is necessary, Dr. Wood and the Gillette Children’s Specialty Healthcare team consider both the degree of deformity and the likelihood of elevated intracranial pressure.
“The first question we ask when planning treatment is whether the head shape is abnormal enough that it will present a significant psychosocial problem as the child grows and begins interacting with his or her peers,” Dr. Wood says. “The answer to that question is typically yes. If the answer is no, we then have to look at brain growth. If brain growth is compressed, which forces the brain to grow in abnormal dimensions, pressure can build up inside the skull.”
When left untreated, intracranial pressure can continue to worsen and cause a variety of complications. In milder cases, it can lead to headaches and mild cognitive delays. At its most severe, elevated intracranial pressure can cause intellectual disability, blindness and even death. However, Dr. Wood notes that, at least in the United States, the diagnosis and management of craniosynostosis has progressed to the point where the disease is usually treated surgically before these severe or fatal complications can occur.
To confirm a craniosynostosis diagnosis and identify the affected area of the cranial vault, Dr. Wood typically performs a noninvasive CT scan that requires no IV contrast or sedation. If a child’s head shape appears relatively normal, but the child is experiencing symptoms of elevated intracranial pressure, physicians may recommend an MRI or retinal examination. The final diagnostic option involves invasively monitoring intracranial pressure overnight, but most cases do not require such tests, and this procedure is rarely utilized at Gillette Children’s Specialty Healthcare.
The “Bloodless” Procedure
Dr. Wood considers 4 months the ideal age to surgically correct fusion of the sagittal suture and 6 months the ideal age to surgically correct fusion of the coronal, metopic and lambdoid sutures.
To perform the procedure, Dr. Wood makes an incision in the scalp to expose the bones of the cranial vault. A strip craniectomy and remodeling is utilized to treat scaphocephaly, and the repair takes place inside the skull. For other types of craniosynostosis, the bones are removed, reshaped and fixed in a normal position within the skull. Though the procedure boasts excellent outcomes, the accepted transfusion rate during cranial vault remodeling surgery ranges from 90 to 100 percent, according to Dr. Wood — a concerning statistic, as blood transfusions can raise a child’s risk of postoperative infection and other adverse reactions.
In October 2013, Dr. Wood began rethinking his approach to cranial vault remodeling in an attempt to reduce the need for transfusion. His analysis, coupled with the vast expertise he has gained from caring for children with craniosynostosis for more than 20 years, led to the development of a four-step protocol designed to minimize bleeding during surgery. The actual surgical technique Dr. Wood uses to perform cranial vault remodeling has changed very little, but the preoperative preparation, instrumentation and medication administration has.
During the three weeks leading up to surgery, patients receive weekly injections of erythropoietin, a hormone produced by the kidneys that stimulates the production of red blood cells. These injections, which have long been used to treat children with hemophilia and other inherited bleeding disorders, help boost the child’s red blood count prior to surgery. Typically, Gillette Children’s Specialty Healthcare can arrange for these injections to take place in patients’ hometowns, eliminating the need for travel.
At the start of the procedure, Dr. Wood administers a dose of tranexamic acid, an antifibrinolytic drug that stabilizes blood clots and prevents them from breaking down. To make the incision and perform dissection, he also uses the Medtronic PEAK PlasmaBlade System instead of a cold-steel blade.
“The system cuts tissue not with an electric current like a cautery device, but with plasma — a tiny cloud of charged ions located at the tip of the device,” Dr. Wood says. “The PlasmaBlade cuts tissue with very minimal damage, and it also coagulates blood.”
When Dr. Wood makes the incision, he utilizes a tumescent technique typically used for liposuction. A very large dose — averaging 30 cubic centimeters (cc) for a 6-month-old child — of dilute lidocaine and epinephrine is injected into the scalp to act as a vasoconstrictor. Finally, Dr. Wood employs the principles of hemodilution. Children receive intravenous saline solution to dilute their blood during surgery, so actual blood loss during the procedure is reduced.
“The amount of saline solution we use is modest and variable,” Dr. Wood says. “We don’t have a specific regimen, but the dose typically ranges from 200 to 300 cc of saline. If, after these measures, a child’s hemoglobin still drops below 7 grams per deciliter, we will move forward with transfusion.”
Children undergoing a primary repair who are less than 12 months of age are considered candidates for the blood-sparing protocol. To date, Dr. Wood has used the protocol for 108 children who underwent cranial vault remodeling at Gillette Children’s Specialty Healthcare with great success.
“The transfusion rate for children with sagittal craniosynostosis has dropped from 100 percent to 17.6 percent, and the operative time averages 57 minutes,” Dr. Wood says. “The transfusion rate for anterior repair has dropped from 100 percent to 32 percent, with an average operative time of 87 minutes.”
Dr. Wood has presented these findings at several conferences and meetings in Korea, Sweden and Japan. While use of the protocol is important, he credits his team’s success, in large part, to their experience.
“Because we’ve done so many of these surgeries, we can accomplish them quickly,” Dr. Wood says. “We perform the same procedures, but in a fraction of the time it takes elsewhere, which also helps mitigate blood loss. What is a three- to seven-hour procedure at many institutions is a one- to one-and-a-half-hour surgery at Gillette Children’s Specialty Healthcare.”
For more information about craniosynostosis or the world-class care provided at Gillette Children’s Specialty Healthcare, visit gillettechildrens.org.