Liam Dalton of Rockville Center, NY, was in the sixth grade when his headaches started. He complained of intermittent pain at first. Over the next few months, his headaches became increasingly severe and frequent – always on the left side of his head. The symptoms became worrisome, and at the advice of Liam’s pediatrician, he and his parents were referred to Joseph Maytal, MD, chief of pediatric neurology at Schneider Children’s Hospital (SCH) in New Hyde Park, NY, regarded as one of the best pediatric care institutions in the country, for a thorough evaluation. Liam underwent a magnetic resonance imaging (MRI) scan, which revealed a potentially dangerous AVM deep within the dominant parietal and occipital lobes of his brain. “It was all very scary, even surreal,” recalls Kerry Dalton, Liam’s mother. “Liam had never been sick before and now we were in a kind of no man’s land not knowing what to expect.”
Just before Christmas in 2005, the family met with Mark A. Mittler, MD, co-chief of pediatric neurosurgery at SCH. Dr. Mittler and Steven Schneider, MD, are SCH’s two dualboard- certified pediatric neurosurgeons. Dr. Mittler confirmed the diagnosis and outlined a strategy for treatment. “When I met Liam and his parents, it was quite clear that his recent symptoms were related to this abnormality,” said Dr. Mittler. “The most important decision to be made, of course, is whether to embark on treatment for a congenital vascular malformation. There are many factors that must be considered, including the type of malformation, its location within the brain, as well as the child’s signs and symptoms. All of these factors allow us to sit down with parents and carefully discuss the risks of intervention and realistic goals. There are instances that, despite our abilities, the risk of treatment is worse than the risk of doing nothing.
In Liam’s case, the progressive headaches were an ominous sign. Despite the AVM’s location in his dominant hemisphere, we were confident that a cure could be achieved.” In general, three forms of treatment exist for AVMs – endovascular embolization, surgery and radiosurgery. Combinations of these techniques are often utilized to obliterate the danger associated with these vascular lesions. Endovascular embolization can be performed in conjunction with an initial diagnostic angiogram. Injection of acrylic glue within the blood vessels can block portions of the abnormal flow of blood through the abnormality. This can be performed a number of times to gradually decrease the blood flowing through the AVM, making surgery safer. It is unusual, however, to be able to completely cure an AVM using embolization techniques alone. Once embolization goals have been met, the pediatric neurosurgical team takes over. “Advances in technology have had a dramatic impact on what we are able to achieve in the operating room,” said Dr. Schneider. “Frameless stereotaxy allows us to identify precise anatomic locations within the brain and correlate them to imaging studies obtained prior to surgery. Ultrasound and even intraoperative MRI techniques are able to provide real-time imaging during surgery. State-of-the-art microscopes and endoscopes bring our visualization to extremes we could
only dream of in the past.”
On April 17, 2006, Liam underwent the first stage of his treatment in the hands of Avi Setton, MD, chief of interventional neuroradiology at North Shore University Hospital in Manhasset, NY, and co-director of the Cushing Institute of Neuroscience Brain Aneurysm Center. After meeting the pediatric anesthesiologist, Liam was prepared for his diagnostic angiogram. The procedure identified a number of “feeding arteries” that supplied a high flow of blood to the AVM.
The team met to discuss the findings while Liam remained under general anesthesia. It was felt that there was opportunity to close at least three of these arteries over the course of a number of treatments. The findings were discussed with the Daltons and the decision was made to start Liam’s treatment immediately. Dr. Setton identified the first target blood vessel. “We were able to navigate our catheter directly into the abnormal arterial feeder and make sure that no normal blood vessels downstream would be compromised by embolization,” said Dr. Setton. “Only then were we able to carefully close the artery with injection of a form of glue within the blood vessel itself.” This first stage of treatment provided a dramatic reduction of blood flow through the AVM, however, it was clear that at least two more stages would be needed prior to surgery. Liam was reversed from anesthesia and observed in the pediatric intensive care unit for three days. Already he felt some improvement of his headache at the time of his discharge. Liam returned for two additional embolizations at approximately six-week intervals – both successful at further reducing the blood flow throughout the lesion. By late summer of 2006, Liam and his family began preparation for surgery.
“Dr. Mittler painted a very clear picture of what surgery would entail,” says Ms. Dalton. “Liam is a very smart boy. The honest but reassuring approach earned Liam’s and our trust throughout the process. Our son was as ready for surgery as he could be. ”On August 22, 2006, Liam returned to SCH at North Shore in Manhasset, NY – this time for the definitive removal of the lesion. The day prior, circular stickers were placed at positions all around his scalp and a planning MRI was performed. Knowing the anesthesia team, Liam was surrounded by familiar faces.
Once asleep, fully monitored, and safely secured in position, the scalp stickers were registered to the frameless stereotactic computer and correlated with the prior day’s MRI images. The scalp incision was planned and the area was shaved, sterilized, and protected from the surrounding areas. The scalp was incised exposing the skull. A high-speed, side-cutting air drill was used to perform the craniotomy directly over the arteriovenous malformation. The dura was opened and the microscope was positioned over the field. Using gentle electrocautery and microscopic suction tips, the AVM was meticulously separated from the surrounding brain. “The key to AVM surgery is patience,” said Dr. Mittler, “The anatomy must first be defined in order to identify and close the remaining arterial feeders. The frameless stereotaxy helps us identify not only the feeders, but the precise location of the previously placed embolization glue. Once the feeders are coagulated and cut, the AVM deflates and is able to be removed.”
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The removal of Liam’s AVM proved uneventful. The brain was again inspected, the dura was closed, the bone flap was secured in position with small titanium plates and screws, and the scalp sutured and stapled closed. “Dr. Mittler appeared with a smile on his face,” recalled Ms. Dalton. “He said that everything had gone exactly as expected, the prognosis was excellent, and Liam was beginning to wake up. We were soon able to see Liam awake and moving everything in the recovery room. Over the next few days he received almost constant attention in the pediatric intensive care unit. We watched as our son continued to improve, and within two days he was walking, eating and laughing like his normal self. We actually took him home straight from the ICU. It was really incredible.” Today, Liam is 14-years-old and able to do everything normal boys do and then some. His mother adds, “We couldn’t be more grateful to the miracle workers at Schneider Children’s Hospital and North Shore.”