Tandem Detethering: A Novel One-Stage Approach Combining Cervicothoracic Cord Release Followed by Filum Terminale Sectioning.

Background/

Objectives

We report a prospective series of five patients with symptomatic cervicothoracic spinal cord tethering from prior surgical interventions for acquired and congenital spinal pathologies. Each patient demonstrated incidental radiographic evidence of a low-lying conus or a fatty/thickened filum terminale (FT), suggesting concomitant symptomatic conus tethering as a potential contributor. Therefore, all underwent single-stage "tandem detethering", consisting of microsurgical release of the cervicothoracic pathology followed by FT resection.

Methods

Patients' charts were reviewed for preoperative presentation, imaging, intraoperative findings, surgical details, FT pathology, and six-month outcomes.

Results

Preoperative tethering occurred at sites of prior interventions: (i) thoracic arachnoid cyst decompression after Chiari surgery, (ii) cervical lipomyelomeningocele repair, (iii) thoracic ependymoma resection, (iv) syringosubarachnoid shunt placement, and (v) laminectomies for recurrent syrinx. Lumbar MRI demonstrated a low-lying conus in two patients and a fatty/thickened FT in four patients. Intraoperatively, all patients exhibited an abnormal FT (tight, fat-infiltrated, thickened, or dysplastic). No intraoperative complications or neuromonitoring abnormalities were observed. At six months, all patients demonstrated improvement in motor, sensory, pain, and urinary/bowel symptoms. Complications included two pseudomeningoceles requiring repair and one case of recurrent cauda tethering following FT resection.

Conclusions

In patients with symptomatic cervicothoracic tethering, a concomitant low-lying conus or pathological FT may contribute to symptomatology by perpetuating biomechanical stress and, if not surgically addressed, may limit neurological recovery. This concept provides a rationale for considering tandem detethering under such circumstances.