The lumbosacral angle does not reflect progressive tethered cord syndrome in children with spinal dysraphism

Utilizing pre- and postoperative radiological parameters to predict surgical outcomes following untethering for tethered cord syndrome in a pediatric population

OBJECTIVE

Tethered cord syndrome (TCS) can lead to significant downstream neurological deficits including gait deterioration, incontinence, and often unexplained chronic low-back pain. Surgical intervention may relieve symptoms, but there are no defined radiological parameters associated with surgical outcomes and functional status. The authors aimed to define pre- and postoperative radiological parameters for assessing surgical outcomes in TCS.

METHODS

The authors performed a single-center retrospective review of all pediatric patients treated for TCS between 2016 and 2021. Patient baseline characteristics and operative metrics included age, sex, level of conus, level of procedure, tethering pathology, symptoms at presentation, complications, improvement of symptoms, and reoperation rate. MRI measurements included pre- and postoperative anterior canal distance (ACD) and bending angle (BA).

RESULTS

Thirty-three pediatric patients were identified who underwent untethering of the spinal cord and had pre- and postoperative MRI between 2016 and 2021. The mean patient age was 5.64 ± 5.33 years. Twenty patients (60.60%) were female. Regarding the site of untethering, 31 procedures (93.93%) were performed at the lumbosacral region and 2 (6.06%) were performed at the thoracolumbar region. The conus medullaris was found above L3 in 21.21% of patients. Postoperatively, 18.18% of patients experienced complications, 48.48% showed improvement in their symptoms, and 48.48% were equivocal or had persistent symptoms. The mean preoperative ACD0 (measured from the posterior vertebral body margin [middle] to the anterior margin of the conus medullaris) was 6.15 ± 3.18 mm, the postoperative ACD0 was 2.25 ± 2.72 mm, and the average change in ACD0 was -0.90 ± 1.31 mm. The mean preoperative BA was 26.00° ± 11.56°, the mean postoperative BA was 15.92° ± 9.81°, and the average change in BA was -10.08° ± 8.80°. An optimal cutoff value for preoperative BA to predict reoperation in pediatric patients with complex TCS undergoing surgery was ≥ 31.70° (area under the curve = 0.83).

CONCLUSIONS

In surgically treated patients with TCS, certain preoperative radiological parameters may be important in predicting postoperative surgical outcomes; these parameters can be evaluated and reported to indicate patients at high risk for complications. Further prospective multicenter research is warranted to offer robust evidence of association of patient outcomes with preoperative radiological parameters in TCS.

Retethering : A Neurosurgical Viewpoint

During the follow-up period after surgery for spinal dysraphism, a certain portion of patients show neurological deterioration and its secondary phenomena, such as motor, sensory or sphincter changes, foot and spinal deformities, pain, and spasticity. These clinical manifestations are caused by tethering effects on the neural structures at the site of previous operation. The widespread recognition of retethering drew the attention of medical professionals of various specialties because of its incidence, which is not low when surveillance is adequate, and its progressive nature. This article reviews the literature on the incidence and timing of deterioration, predisposing factors for retethering, clinical manifestations, diagnosis, surgical treatment and its complications, clinical outcomes, prognostic factors after retethering surgery and preventive measures of retethering. Current practice and opinions of Seoul National University Children’s Hospital team were added in some parts. The literature shows a wide range of data regarding the incidence, rate and degree of surgical complications and long-term outcomes. The method of prevention is still one of the main topics of this entity. Although alternatives such as spinal column shortening were introduced, re-untethering by conventional surgical methods remains the current main management tool. Re-untethering surgery is a much more difficult task than primary untethering surgery. Updated publications include strong skepticism on re-untethering surgery in a certain group of patients, though it is from a minority of research groups. For all of the abovementioned reasons, new information and ideas on the early diagnosis, treatment and prevention of retethering are critically necessary in this era.

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

AIMS

As awareness and frequency of tethered spinal cord (TSC) related to occult spinal dysraphism (OSD) has increased with magnetic resonance imaging (MRI), variability exists in its evaluation and management. Due to no published level I data, we summarize the current International Children's Continence Society (ICCS) recommendations for diagnosis and treatment of OSD.

METHODS

Guidelines were formulated based on analysis of pertinent literature and consensus among authors. This document was vetted by the multidisciplinary members of the ICCS via its website before submission for peer review publication.

RESULTS

The more frequent diagnosis of OSD is associated with increased operative intervention. Spinal cord untethering (SCU) has a highly variable risk profile, largely dependent on the specific form of OSD. Progressive neurological deterioration attributed to "tethered cord" may occur, with or without surgery, in selected forms of OSD whereas other cohorts do well.

CONCLUSION

Infants with classic cutaneous markers of OSD, with progressive neurologic, skeletal, and/or urologic findings, present no diagnostic or therapeutic dilemma: they routinely undergo MRI and SCU. Conversely, in asymptomatic patients or those with fixed, minor abnormalities, the risk profile of these OSD cohorts should be carefully considered before SCU is performed. Irrespective of whether or not SCU is performed, patients at risk for progression should be followed carefully throughout childhood and adolescence by a multidisciplinary team.

The International Tethered Cord Partnership: Beginnings, process, and status

Background:

Spina bifida presents a significant cause of childhood morbidity in lower- and middle-income nations. Unfortunately, there is a paucity of literature examining outcomes among children with spina bifida in these countries. The goal of the International Tethered Cord Parternship is twofold: (1) to establish an international surveillance database to examine the correlation between time of repair and clinical outcomes in children with spina bifida and tethered cord; and (2) to foster collaboration among international institutions around pediatric neurosurgical concerns.

Methods:

Twelve institutions in 7 countries committed to participating in the International Tethered Cord Partnership. A neurosurgeon at each institution will evaluate all children presenting with spina bifida and/or tethered cord using the survey instrument after appropriate consent is obtained. The instrument was developed collaboratively and based on previous measures of motor and sensory function, ambulation, and continence. All institutions who have begun collecting data received appropriate Institutional Review Board approval. All data will be entered into a Health Insurance Portability and Accountability Act (HIPAA) compliant database. In addition, a participant restricted internet forum was created to foster communication and includes non–project-specific communications, such as case and journal article discussion.

Results:

From October 2010 to December 2010, 82 patients were entered from the various study sites.

Conclusion:

To our knowledge this is the first international pediatric neurosurgical database focused on clinical outcomes and predictors of disease progression. The collaborative nature of the project will not only increase knowledge of spina bifida and tethered cord, but also foster discussion and further collaboration between neurosurgeons internationally.