UB surgeons use computer-assisted surgery to reduce head size

BUFFALO, N.Y. ­­­— Up to 5% of infants today are born with abnormally large heads, a condition known as macrocephaly. While it can be genetic, the condition is often caused by hydrocephalus, or an imbalance in fluid production and absorption in the brain.

Untreated hydrocephalus can result in a range of issues from headaches to visual problems and can be life threatening, noted Michael Markiewicz, DDS, MPH, MD, professor and chair of the Department of Oral and Maxillofacial Surgery and associate dean for hospital affairs in the University at Buffalo School of Dental Medicine.

Fortunately, hydrocephalus can be successfully treated by placing a shunt in the brain to control the excess fluid and pressure. However, more severe cases of macrocephaly can persist and result in unsteady gait, posture control problems, and developmental delays, said Markiewicz, who also serves as the clinical co-director of the Laurence C. Wright Craniofacial Center at John R. Oishei Children’s Hospital in Buffalo.

In these cases, reduction cranioplasty is the best option for management, he said.

“Reduction cranioplasty, which usually is performed in patients age 2 and older, reduces head circumference, restores symmetry and normalizes head shape,” he said.

Along with Renee Reynolds, MD, clinical associate professor in the Department of Neurosurgery in the Jacobs School of Medicine and Biomedical Sciences and medical director of pediatric neurosurgical outreach and education at Kaleida Health, Markiewicz has used computer-aided design (CAD) and computer-aided manufacturing (CAM) in reduction cranioplasty numerous times.

David Best, a former pediatric craniomaxillofacial surgery fellow and current surgeon at Boston Children’s Hospital who worked under Markiewicz last year, co-authored a paper with Markiewicz outlining the benefits and drawbacks of using CAD and CAM in the surgeries. They included case studies of three children between the ages 2 and 6 who underwent the procedure at Oishei over the last five years. The paper was recently published in the Cleft Palate Craniofacial Journal.

“While using this digital technology is not a novel procedure — it’s been around for about a decade — we wanted to highlight our success with it,” Markiewicz said. “The surgery can be very risky. We’re operating on the bony skull, but still the brain is exposed and can be at risk during any part of the procedure.”

CAD and CAM systems allows surgeons to design and fabricate accurate craniotomy guides, fixation templates, and models that allow for precise cranial reconstruction.

“We plan the whole surgery virtually after getting a CT scan of the child,” he explained. “Then we can take our time and plan what will make these patients have the best outcomes.”

Advantages include a shorter procedure time, reduced risk to vital structures, and improved predictability of cosmetic outcomes.

“Patients usually go home in four to five days,” he said. “We follow up with them very closely, and they heal quite quickly. We start seeing the positive effects within a few months afterwards.”

But there is no one-size-fits-all design, he emphasized.

“The design of the virtual cranioplasty can be among the most challenging aspects,” he said. “The use of this digital workflow requires expertise from both the surgeon and the engineer, which may have a considerable learning curve for both parties.”

When reshaping the skull, surgeons must also be careful not to harm critical structures inside the head, including the brain itself, the cerebrospinal fluid that cushions and circulates around the brain, and the blood vessels that drain blood from the brain.

“With the digital technology, we’re not blindly going in and risking damage to these structures,” he said. “We can predictably make those cuts using computer planning. With the guides, it’s becoming more efficient and much quicker. And the accessibility is just getting better and better for this technology, meaning most surgeons and hospitals can use it.”

He tempered the benefits with a caveat: as with other forms of cranial vault remodeling, the surgery is considered “partially guided” since intraoperative modifications are often required.

“The surgeon must still respond to problems and make adjustments in real time,” he said. “It is something we’re always cognizant of. While this is a complicated surgery, it’s one that can have great success.”