Surgical volume of simple tethered spinal cord releases: review of a large pediatric neurosurgical service experience

Tethered Cord Syndrome: Role of Imaging Findings in Surgical Decision-Making

For infants presenting with urinary problems or lower extremity weakness, imaging is ordered to investigate spinal pathology. Tethered cord syndrome (TCS) often manifests without conclusive anatomic evidence. In our case, a premature infant presented with urosepsis and was found to have an asymmetric gluteal crease and a sacral dimple. Renal ultrasound showed mild hydronephrosis, and a cystourethrogram revealed bilateral high-grade vesicoureteral reflux. Ultrasound and magnetic resonance imaging demonstrated a borderline low-lying spinal cord at the mid-L3 vertebral level. Urodynamic testing to confirm neurogenic bladder could not be completed on the first attempt due to urinary tract infection and on the second attempt due to instrument intolerance. Despite the lack of conclusive imaging evidence of a tethered cord, enough supportive clinical data was present to proceed with surgical intervention with the goal of preventing the progression of neurological dysfunction. Because TCS is ultimately a clinical diagnosis, appropriate management should not be discouraged by inconclusive or borderline imaging findings.

Fibrofatty filum terminale: long-term outcomes from a Singapore children's hospital

OBJECTIVE

The role of prophylactic detethering a fibrofatty filum terminale (FFT) remains equivocal. Furthermore, long-term studies focusing on urological outcomes are sparse. The aims of this study were to present an institutional experience on the perioperative and long-term outcomes of FFT surgery and to assess for factors that contribute to postoperative clean intermittent catheterization (CIC).

METHODS

This was a single-institution, retrospective study conducted over a 20-year period. Patients younger than 19 years of age who underwent surgery for FFT were included. Variables of interest included patient demographics, clinical presentation, radiological findings, postoperative complications, and long-term need for CIC. Outcomes were measured using the Necker functional score and modified Hoffer Functional Ambulation scale score at 3, 6, and 12 months postdischarge.

RESULTS

A total of 164 surgeries were performed for FFT from 2000 to 2020. The median age at surgery was 1.1 years, and the mean follow-up duration was 8.3 years. There were 115 patients (70.1%) who underwent prophylactic-intent surgery and 49 patients (29.9%) who underwent therapeutic-intent surgery. The proportion of therapeutic-intent surgeries increased significantly with age percentiles (0-20th, 21.9%; 20th-40th, 9.1%; 40th-60th, 18.2%; 60th-80th, 36.4%; and 80th-100th, 63.6% [p < 0.001]). Thirty patients (18.3%) had an associated syndrome, the most common (n = 19, 11.6%) being VACTERL (vertebral defects, anal atresia, cardiac defects, tracheo-esophageal fistula, renal anomalies, and limb abnormalities). Forty-eight patients (29.3%) had an associated malformation (anorectal anomaly = 37, urogenital anomaly = 16, and sacral anomaly = 3). Cutaneous manifestation was the most common presentation (n = 96, 58.5%), followed by lower-limb neurological deficits (n = 21, 12.8%). A low-lying conus was present in 36.0% of patients (n = 59), and 16.5% had an associated syrinx (n = 27). There were 26 patients (18.8%) with an abnormal preoperative urodynamic study. Three patients (1.8%) had postoperative complications that required repeat surgery. There were no cases of CSF leakage. One patient (0.6%) developed retethering requiring another surgery. Postoperative CIC was required in 11 patients (6.7%). Multivariable analyses showed that an abnormal preoperative urodynamic study (adjusted OR 5.5 [95% CI 1.27-23.9], p = 0.023) and having an intraspinal syrinx (adjusted OR 5.29 [95% CI 1.06-26.4], p = 0.042) were associated with the need for CIC.

CONCLUSIONS

The authors' results demonstrate that detethering surgery for FFT is a relatively safe procedure and can be performed prophylactically. Nonetheless, the risks of postoperative CIC should be emphasized during the preoperative counseling process.

International survey on the management of lumbosacral cutaneous stigmata in infants with suspected occult spinal dysraphism

OBJECTIVE

Occult spinal dysraphism (OSD) is a common pediatric neurosurgical diagnosis rife with controversy surrounding both the screening of asymptomatic infants and the threshold to offer a prophylactic detethering operation. The authors sought to clarify international practice patterns with a survey of pediatric neurosurgeons.

METHODS

A survey asked pediatric neurosurgeons whether they would perform imaging in patients with a variety of cutaneous stigmata associated with OSD and whether they would offer prophylactic detethering surgery for asymptomatic patients with a variety of imaging findings on the OSD spectrum.

RESULTS

Completed surveys were received from 141 pediatric neurosurgeons. Broad consensus was demonstrated on the need for obtaining images in sample patients with more severe stigmata ranging from large lipoma with a skin appendage to focal dysplastic skin in the lumbar midline. Ninety percent of respondents would perform MRI for these patients. In contrast, for patients with a low-sacral dimple, flat hemangioma, and symmetric (Y-shaped) splaying of the intergluteal cleft, opinion on the need for imaging varied considerably (between 57% and 89% recommended imaging). Respondents differed on the type of imaging that they would perform, with 31% to 38% recommending ultrasound screening. The responses reflected less consensus on when to offer surgery to patients with simple spinal tethering (low-lying conus medullaris and fatty filum terminale). Both a lower level of the conus and increased thickness of the filum terminale affected decision-making.

CONCLUSIONS

The results of this survey showed significant consensus on the recommendation for screening imaging in patients with more dramatic cutaneous stigmata, although these stigmata are the rarest. A significant variance in opinions was reflected in the recommendation for imaging of the most common cutaneous stigmata. Consensus was also lacking on which lesions deserve prophylactic detethering surgery. Significant equipoise exists for future study of screening imaging and of surgical decision-making in patients with asymptomatic OSD and associated cutaneous stigmata.