The innovation: Informing surgical decision-making for optimal outcomes
Pediatric neurosurgeons frequently evaluate children with tight or fatty filum terminale (TFT or FFT), conditions associated with tethered cord syndrome. While surgery is clearly indicated for symptomatic patients, there is no consensus on whether to operate on children without symptoms – many of whom may never develop them. Outcomes also vary, with some patients experiencing retethering after surgery.
To better inform surgical decision-making and optimize outcomes, experts at Children’s Health℠ and UT Southwestern conducted the largest and most comprehensive systematic review and meta-analysis to date of pediatric patients undergoing surgery for TFT or FFT.
“Filum sectioning is one of the most common and technically straightforward tethered cord procedures, yet practice patterns and outcomes vary widely,” says Brett Whittemore, M.D., Pediatric Neurosurgeon at Children’s Health and Associate Professor at UT Southwestern. “Our study examined surgical practice, complication rates and predictors of retethering.”
The analysis identified two key opportunities to improve care: minimizing postoperative cerebrospinal fluid (CSF) leaks and ensuring long-term follow-up for patients who were symptomatic prior to surgery.
Clinical considerations for TFT and FFT: Indications, risks and practice variability
Between 4% and 6% of people have FFT. “It’s so common it’s almost a normal variant in the way people’s spines form,” says Dr. Whittemore. “Just because it’s there doesn’t mean the patient needs treatment. When we find this incidentally on imaging in an adult or older child with normal function, we leave it alone.”
In children who do have bowel or bladder dysfunction or lower extremity weakness, the standard of care is to operate. But the decision can be controversial in symptom-free babies and young children. This is especially true if they’re too young for toilet training (meaning bowel- or bladder-control issues might not be obvious) or if they have other features sometimes linked with tethering, like congenital abnormalities in the lower body.
In the absence of national guidelines or algorithms, some surgeons may recommend cutting the filum to prevent future issues. Others never do this unless there are symptoms or physical signs. Though the risks of surgery for TFT and FFT are low, some providers believe it’s better to avoid any procedure that might not be necessary.
Prior studies have been too small or lacked enough high-quality data to steer surgeons in a single, clear direction. The approach often depends on a surgeon’s early training and clinical experience, along with anecdotal evidence.
Key details: Predictors of retethering
The research team analyzed data from more than 1,100 children across 10 studies. They looked for links between retethering and a range of factors about the patients, their surgeries and their outcomes. They found:
Retethering happened in 3.4% of children after their first surgery. (Some children went on to have another operation to free their spinal cord.) “That’s a very low risk,” says Dr. Whittemore.
More than 80% of symptomatic patients showed improvement at last follow-up. “This suggests surgeons did a good job of choosing patients who could benefit from the operation,” says Dr. Whittemore. Still, he adds, the data provides meaningful benchmarks for surgeons and can help them counsel families accurately on the benefits and risks of surgery.
The strongest predictor of retethering was a CSF leak after surgery. Children with leaks were more than twice as likely to have their spinal cord scar down again. In addition, children who had pain, numbness or tingling before surgery were more likely to have symptoms of retethering than those without sensory changes, whether or not they had a CSF leak.
What the researchers didn’t find was also intriguing.
There was no link between retethering and the conus level, where the spinal cord ends.
Also, while the analysis didn’t prove a link between retethering and suture type, the data suggested risk might be higher in patients with absorbable sutures.
“Our findings can help surgeons evaluate their own practice both from a decision-making standpoint – such as who we are offering surgery to – and from a technical standpoint, such as what we can do to minimize CSF leak,” says Dr. Whittemore.
Applying the findings: Surgical protocols
At an institutional level, the research translates into important opportunities to refine surgical protocols and tailor follow-up regimens. Such as:
Meticulous closure of the dura is essential to prevent CSF leaks.
Keeping patients lying flat for 24 hours after surgery to reduce pressure on the suture line and leak risk.
Longer follow-up may be warranted in children who had sensory changes before surgery, even if they seem fine at the one-year mark.
Following patients longer may help surgeons spot symptoms of retethering that may come on gradually, sometimes not for years.
Pioneers in pediatric neurosurgery and neurological care
Children’s Health and UT Southwestern are leaders in pediatric neurosurgery, providing the latest, most effective care for children with tethered spinal cords. This new meta-analysis on TFT or FFT is aiding in advancing care and optimal outcomes for pediatric patients nationwide.
“These study results can serve as a benchmark for us and for others in the field who want to give children the best care, based not only on our original training and years of experience, but also on the strongest evidence available,” says Dr. Whittemore.
In addition, their pediatric neurosurgery program is the only one in North Texas offering microsurgery, endoscopy, Gamma Knife radiosurgery, endovascular neurosurgery and minimally invasive skull base surgery – all in one location.
Learn more about the innovative Pediatric Neurosurgery Program at Children’s Health.
