Retethering in Children after Sectioning of the Filum Terminale

Abstract

Background/Aim: Sectioning of the filum terminale is performed when spinal cord tethering is suspected, sometimes without clinical symptoms. Retethering can occur and require reoperation due to the presentation of either recurrent or new symptoms. The purpose of this institutional review was to identify the retethering rate in children, especially in those who were initially asymptomatic, and to discuss the role of surgery. Methods: The medical records of all children at the Children's Hospital of Eastern Ontario (CHEO) who underwent tethered cord surgery between 1978 and 2009 for a thickened filum terminale were retrospectively reviewed, as well as those who retethered. Results: A total of 146 patients with a mean age of 4.3 years underwent a low lumbar single or partial laminectomy for sectioning of the filum terminale; 44 patients (30.1%) were asymptomatic at the time of surgery, 51.4% had bladder and bowel dysfunction, 26.7% had neuroorthopedic findings, 15.8% had pain and 6.2% had progressive scoliosis; 11 children with a median age of 8.9 years had symptoms of retethering requiring reoperation (median time to retether was 4.3 years) and 4 were initially asymptomatic. Repeat surgery was successful at alleviating the new symptoms that occurred as a result of retethering. Conclusions: Of the 146 patients at CHEO who underwent surgery, 7.5% retethered, with 36% being initially asymptomatic. Those operated in the first year of life were not found to be at a higher risk. The level of the conus medullaris did not influence the rate or retethering or urological dysfunction. Children who were initially asymptomatic improved after surgery for retethering, but may not have required surgery in the first place.

Evaluation and management of tethered cord syndrome in occult spinal dysraphism: Recommendations from the international children's continence society

“…All TSC, regardless of whether they have undergone SCU, are at risk for clinical decline. SCU does not eliminate the possibility that deterioration may occur later, even for the simplest form of TSC (fatty filum) …”

Fecal incontinence as a predominant symptom in a case of multiply recurrent tethered cord: diagnosis and operative strategies

“…1,10,15 Despite generally successful initial procedures, retethering is a very difficult to manage postoperative complication. Surgical series have shown retethering rates approaching 45% in more complex cases of myelomeningocele and lipomyelomeningocele; in cases of thick/fatty filum terminale sectioning, considerably lower rates have been reported, and scattered reports in the literature cite a retethering rate of about 8%-9% on long-term follow-up.…”

“…6,7,16 Most retethering is attributed to scar and arachnoid adherence around the neural elements attached to the spinal meninges, developing traction and nerve root dysfunction over time. 15 Maintenance of a pristine subarachnoid space during surgery and robust irrigation prior to dural closure have been espoused as technical nuances thought to minimize the risk of intradural adhesion. Expansile duraplasty has also been advocated to create more subarachnoid space, although it does introduce 2 new sites of potential adhesion at the suture line.…”

“…Rates of retethering after sectioning a fatty filum terminale are low. 15,16 Retethering may produce neurological symptoms through nerve root traction and ischemia or tension distributed through the spinal cord. 3,4,12 We present a case of simple tethered cord due to a fatty filum terminale with 3 distinct episodes of recurrence, each presenting with fecal incontinence and resolving with operative intervention.…”

Adolescent Idiopathic Scoliosis: Etiological concepts and implication for treatment

“…Implications for treatment however have not yet been derived from the findings as published to date with the exception of spinal manipulation described by Tomaschewski 10 or neurosurgical release of the filum terminale as described by Royo-Salvador 12 . Retethering after sectioning of the filum terminale has been described 13 . Following the rationale of Tomaschewski 10 , external manipulation might influence IFF, the 'flatback' contracture as found in the lower thoracic area in patients with beginning AIS and have a beneficial effect on the 3D deformity of the spine and trunk.…”