Use of lumbar ultrasonography to detect occult spinal dysraphism

Complex lumbosacral spinal cord lipomas: A longitudinal study on outcomes from a Singapore children's hospital

BACKGROUND

Total/near-total resection (TR/NTR) of complex lumbosacral lipomas (CSL) is reported to be associated with better long-term functional outcomes and lower symptomatic re-tethering rates. We report our institutional experience for CSL resection in affected children.

METHODS

This is a single-institution, retrospective study. Inclusion criteria consist of patients with CSL with dorsal, transitional and chaotic lipomas based on Pang et al's classification. The study population is divided into 2 groups: asymptomatic patients with a normal preoperative workup referred to as 'prophylactic intent' and 'therapeutic intent' for those with pre-existing neuro-urological symptoms. Primary aims are to review factors that affect post-operative clean intermittent catheterization (CIC), functional outcomes based on Necker functional score (NFS), and re-tethering rates.

RESULTS

122 patients were included from 2000 to 2021. There were 32 dorsal lipomas (26.2 %), 74 transitional lipomas (60.7 %), and 16 chaotic lipomas (13.1 %). 82 % patients achieved TR/NTR. Favourable NFS at 1-year was 48.2 %. The re-tethering rate was 6.6 %. After multivariable analysis, post-operative CIC was associated with median age at surgery (p = 0.026), lipoma type (p = 0.029), conus height (p = 0.048) and prophylactic intent (p < 0.001). Next, extent of lipoma resection (p = 0.012) and the post-operative CSF leak (p = 0.004) were associated with re-tethering. Favourable NFS was associated with lipoma type (p = 0.047) and prophylactic intent surgery (p < 0.001).

CONCLUSIONS

Our experience shows that TR/NTR for CSL is a feasible option to prevent functional deterioration and re-tethering. Efforts are needed to work on factors associated with post-operative CIC.

Use of ultrasound to estimate the prevalence of occult spinal dysraphism in children undergoing urogenital and anorectal surgeries: A cross-sectional study

Background and Aim

The use of ultrasound has immensely increased the safety toward regional blocks and central venous access and has been considered as the standard of care for securing central access. The aim of this study is to estimate the prevalence of occult spinal dysraphism using ultrasound in children less than 2 years of age undergoing elective urogenital or anorectal surgery.

Material and Methods

The lumbosacral region of 159 American Society of Anesthesiologists (ASA) category I/II patients, posted for elective urogenital and anorectal surgery was scanned with ultrasound, prior to giving caudal block.

Results

The prevalence of occult spina bifida was 3% in our study. There was no statistically significant association of cutaneous marker with abnormal scan.

Conclusion

Prevalence of occult spina bifida was ten-times higher in our study than in the general population. Perioperative ultrasound screening of the lower spinal anatomy by anesthesiologist done prior to performing neuraxial block is worthwhile in ruling out occult spinal anomalies in high-risk children of occult spinal dysraphism.

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.

Multi-Institutional Review From the Pediatric Colorectal and Pelvic Learning Consortium of Minor Spinal Cord Dysraphism in the Setting of Anorectal Malformations: Diagnosis, Treatment, and Outcomes

BACKGROUND/RATIONALE

Anorectal malformations (ARM) are associated with congenital anomalies of the spine, but the impact of a minor spinal cord dysraphism (mSCD) on fecal continence in the setting of ARM remains unclear.

MATERIALS/METHODS

A retrospective review was performed utilizing data from the Pediatric Colorectal and Pelvic Learning Consortium (PCPLC) registry. The patient cohort was reviewed for ARM type, mSCD screening/incidence/neurosurgical intervention and age-based BMP utilization.

RESULTS

987 patients with ARM were categorized into mild (38%), moderate (32%) or complex (19%). 694 (70%) had normal spinal (NS) status. 271 (27.5%) patients had mSCD. MRI alone (49%) was the most common screening test for mSCD. US screening had a positive predictive value of 86.3% and a negative predictive value of 67.1%. Surgical intervention rates for mSCD ranged between 13% and 77% at a median age of 0.6-5.2 years. 726 (73.6%) patients were prescribed BMP (74.4% NS, 77.5% mSCD). Laxatives were most utilized BMP in all groups <5yo. ≥5yo, enema utilization increased with ARM complexity independent of spine status (with or without neurosurgical intervention). Neurosurgical intervention did not affect BMP utilization at any age or with any ARM when mSCD was identified.

CONCLUSIONS

MSCD influence on bowel function in the setting ARM remains unclear. No significant impact of mSCD was noted on ARM patient bowel management program utilization. Variability exists within PCPLC site with screening and intervention for mSCD in patients with ARM. Future studies with standardized care may be needed to elucidate the true impact of mSCD on long term patient outcomes in ARM patients.

TYPE OF STUDY

Retrospective Comparative Study.

LEVEL OF EVIDENCE

III.

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.

Tethered cord secondary to focal nondisjunction of the primary neural tube: experience from a Singapore children's hospital

PURPOSE

Tethered cord due to focal nondisjunction of primary neuralisation (FNPN) is a rare form of spinal dysraphism. We present our institutional experience in managing children diagnosed with FNPN.

MATERIALS AND METHODS

This is a single institution, retrospective study approved by the hospital ethics board. Patients below 18 years of age diagnosed with CDS, LDM or their mixed lesions, and subsequently underwent intervention by the Neurosurgical Service, KK Women's and Children's Hospital, are included.

RESULTS

From 2001 to 2021, 16 FNPN patients (50% males) were recruited. Eight of them had CDS (50.0%), seven had LDM (43.8%), and one patient had a mixed CDS and LDM lesion (6.2%). The average duration of follow up was 5.7 years and the mean age of surgery was 6 months old. Thirteen patients underwent prophylactic intent surgery (81.2%) and three had therapeutic intent surgery (18.8%). All patients did not have new neurological deficit or required repeat surgery for cord retethering. We observed that detethering surgery performed at or less than three months old was associated with having a wound infection (p = .022).

CONCLUSIONS

Our study reports that early recognition and timely intervention are mainstays of management for FNPN. We advocate a multi-disciplinary approach for good outcomes.

Incidence of Occult Spinal Dysraphism Among Infants With Cutaneous Stigmata and Proportion Managed With Neurosurgery: A Systematic Review and Meta-analysis

IMPORTANCE

Occult spinal dysraphism (OSD) is the most common congenital spinal anomaly. Cutaneous anomalies such as skin dimples or deviated gluteal folds are well known as stigmata of OSD and are indicators for further evaluation; however, the association between cutaneous anomalies and OSD has not been systemically evaluated.

OBJECTIVE

To evaluate the incidence of OSD and the proportion of OSD cases managed with a neurosurgical intervention among neonates or infants with various cutaneous stigmata.

DATA SOURCES

PubMed and Embase databases were searched for studies published up to July 25, 2018, that evaluated the proportion of OSD cases in neonates or infants with cutaneous stigmata. Search terms included ultrasound, dysraphism, dimple, and infant or neonate. The search was limited to English-language publications.

STUDY SELECTION

Two reviewers selected the studies evaluating the incidence of OSD among neonates or infants with cutaneous stigmata.

DATA EXTRACTION AND SYNTHESIS

The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines for data extraction were followed. Pooled proportions of OSD cases and OSD cases that were managed with a neurosurgical intervention were obtained using the generalized linear mixed model and maximum likelihood method.

MAIN OUTCOME AND MEASURES

The pooled incidence of OSD and OSD cases managed with neurological surgery among patients with cutaneous stigmata was the primary outcome. This outcome was also evaluated in each subgroup, and heterogeneity was explored using subgroup analysis.

RESULTS

A total of 15 studies, involving 6558 neonate or infant patients with various cutaneous stigmata, were included. The pooled proportion of OSD cases among the patients with cutaneous stigmata was 2.8% (95% CI, 2.1%-3.8%; I2 = 51.6%), and the proportion managed with neurological surgery was 0.6% (95% CI, 0.3%-1.3%; I2 = 66.4%). Cases with combined stigmata showed a significantly higher association with OSD than those with a single stigma (10.5% [95% CI, 6.9%-15.8%] vs 2.3% [%, 95% CI, 1.5%-3.5%]; P < .001). The pooled proportion of OSD cases among patients with an atypical dimple was significantly higher than among those with simple dimple (8.8% [95% CI, 4.5%-16.6%] vs 0.6% [95% CI of 1.4%-2.1%]; P = .001).

CONCLUSIONS AND RELEVANCE

The proportion of OSD in healthy, asymptomatic patients with midline cutaneous stigmata was low, and the proportion of patients who underwent a neurosurgical intervention was even lower. However, a careful evaluation as well as potential spinal magnetic resonance imaging is recommended for neonates or infants with combined stigmata or an atypical dimple for possible high-risk lesions.

[Cutaneous signs of occult cranial and spinal dysraphism]

Dysraphism refers to neural tube closure abnormalities and midline closure abnormalities of the skin, paravertebral muscles, vertebrae and meninges. Cranial dysraphism (CD) and occult spinal dysraphism (OSD) may be discovered via evocative skin signs present at birth or appearing later in childhood or even in adulthood. This review describes the various types of skin signs associated with CD and OSD. All congenital midline skin lesions, particularly on the frontonasal area, the vertex or the occipitocervical and low back regions, should prompt suspicion of underlying dysraphism. The main evocative midline skin abnormalities are: (i) for underlying DCEO: a nodule, swelling, skin openings and hair collar sign or hair tuft; (ii) for underlying DSO, localized hypertrichosis, an atypical or complex lower back dimple, a dermoid fistula, infantile haemangioma, caudal appendage and lipoma. In the event of suspected DCEO or DSO, spinal or medullary MRI constitutes the reference examination.

Perioperative ultrasound imaging versus magnetic resonance imaging in management of lumbosacral spinal dysraphisms

Objectives

The purpose of this study was to correlate lumbosacral spinal ultrasound (LUS) and magnetic resonance imaging (MRI) findings in patients with lumbosacral spinal dysraphisms to evaluate the value of LUS in diagnosis, intraoperative use, and during follow-up of those patients.

Methods

A total of 24 patients aged up to 6 years old were operated for lumbosacral spinal dysraphisms at the Neurosurgery Department of Zagazig University hospitals during the period from January 2017 to August 2018. All patients were investigated preoperatively, intraoperatively, and on follow-up by LUS to compare the data with preoperative and follow-up MRI of the spine.

Results

The median age was 11 months at the time of surgery. The most common anatomical description from the LUS study was thickened filum (18 cases). Using MRI findings as the standard reference, the sensitivity of LUS in detecting a thickened filum was 77.8% preoperatively and 62.5% postoperatively, with a specificity of 100%. The sensitivity and specificity of detecting conus level, solid masses, and cystic masses were 100%.

Conclusions

Lumbosacral spinal dysraphisms can be evaluated well by ultrasound imaging in age group up to 6 years old with 100% specificity (true negative) in comparison with MRI.

Importance of Physical Examination and Imaging in the Detection of Tethered Cord Syndrome

Tethered cord syndrome (TCS) is a type of occult spinal dysraphism that may lead to permanent neurologic and orthopedic deficits. Infants with TCS may have lumbosacral cutaneous malformations (LsCMs). We studied 67 infants referred to a single pediatric urology practice for a urological concern unrelated to occult spinal dysraphism with no prior diagnosis of LsCM between March 1, 2015 and September 30, 2018. Each infant underwent a spinal ultrasound. If an abnormality was detected, they were referred to a pediatric neurosurgeon. The most common cutaneous manifestations were duplicated or bifurcated (46%) gluteal folds and gluteal asymmetry (16%). Fourteen (21%) of the 67 patients had an abnormal spinal ultrasound; 5 of the 14 infants underwent a lumbar magnetic resonance imaging. One infant had urodynamics studies and a tethered cord release. Pediatricians should be familiar with TCS and perform lumbar physical examinations for LsCMs suggestive of TCS to ensure prompt diagnosis and management and avoid potentially devastating complications.

Spinal cord ultrasonography of the newborn

Ultrasound represents the first-line survey for the assessment of spinal cord development abnormalities. In fact, within 6 months of life, the non-ossification of neuronal arcs provides an excellent acoustic window that allows a detailed depiction of the spinal canal, its content and of the surrounding soft tissues. Nevertheless, an accurate ultrasound examination requires a complete knowledge of the anatomy, the condition of normality, the frequent anatomical variants and the main pathologies involved. This review is intended to briefly summarize the US technique, the main clinical indication and the key notions that could help to properly perform this type of ultrasound examination.

Dorsal midline cutaneous stigmata associated with occult spinal dysraphism in pediatric patients

PURPOSE

To investigate the prevalence of occult spinal dysraphism (OSD) and subsequent neurosurgery in pediatric patients with isolated or combined dorsal midline cutaneous stigmata with or without other congenital malformations.

METHODS

We carried out a retrospective review of patients who underwent sonography or magnetic resonance imaging (MRI) for OSD because of suspicion of dorsal midline cutaneous stigmata (presumed to be a marker for OSD) between January 2012 and June 2017. Information about patient characteristics, physical examination findings, spinal ultrasound and MRI results, neurosurgical notes, and accompanying congenital anomalies was collected.

RESULTS

Totally 250 patients (249 ultrasound and one MRI screening) were enrolled for analysis. Eleven patients underwent secondary MRI examinations. The prevalence of OSD confirmed by an MRI was 2.4% (6 patients including one MRI screening). Five patients (2%) had tethered cord and underwent prophylactic neurosurgery, 3 of whom had a sacrococcygeal dimple and a fibrofatty mass. Prevalence of tethered cord increased as markers associated with a sacrococcygeal dimple increased (0.5% of the isolated marker group, 8.1% of the 2-marker group, and 50% of the 3-marker group). Incidence of OSD with surgical detethering in 17 other congenital anomaly patients was 11.8%, which was higher than the 1.3% in 233 patients without other congenital anomalies.

CONCLUSION

Our results suggest that the presence of dorsal midline cutaneous stigmata, particularly fibrofatty masses, along with a sacrococcygeal dimple is associated with OSD or cord tethering requiring surgery. OSD should be suspected in patients with concurrent occurrence of other congenital anomalies.

Outcome of ultrasonographic imaging in infants with sacral dimple

Purpose

Sacral dimples are a common cutaneous anomaly in infants. Spine ultrasonography (USG) is an effective and safe screening tool for patients with a sacral dimple. The aim of this study was to determine the clinical manifestations in patients with an isolated sacral dimple and to review the management of spinal cord abnormalities identified with USG.

Methods

We reviewed clinical records and collected data on admissions for a sacral dimple from March 2014 through February 2017 that were evaluated with spine USG by a pediatric radiologist. During the same period, patients who were admitted for other complaints, but were found to have a sacral dimple were also included.

Results

This study included 230 infants under 6-months-old (130 males and 100 females; mean age 52.8±42.6 days). Thirty-one infants with a sacral dimple had an echogenic filum terminale, and 57 children had a filar cyst. Twenty-seven patients had a low-lying spinal cord, and only one patient was suspected of having a tethered cord. Follow-up spine USG was performed in 28 patients, which showed normalization or insignificant change.

Conclusion

In this study, all but one infant with a sacral dimple had benign imaging findings. USG can be recommended in infants with a sacral dimple for its convenience and safety.

A Cross-Sectional Assessment of Cutaneous Lumbosacral and Coccygeal Physical Examination Findings in a Healthy Newborn Population

Objective. The purpose of this study is to describe the range and frequency of cutaneous lumbosacral and coccygeal findings encountered during the newborn examination in a population of apparently healthy babies, to determine if the prevalence of these findings is associated with race/ethnicity, and to report the frequency of co-occurrence of low-risk cutaneous findings. Methods. Lumbosacral physical findings of 1121 infants were documented on well newborns at least 35 weeks or greater gestational age under the authors’ care. The overall frequency of each physical finding was tabulated in addition to determining whether frequencies varied by race/ethnicity. Co-occurrence of the most common physical findings was also examined. Results. Of 1096 infants included in the study, 24.8% had deviated or duplicated gluteal creases, 15.6% had dimples, and 24.7% had lumbosacral and/or coccygeal hairiness. All racial/ethnic groups had double to quadruple the risk of lumbosacral hair when compared with Caucasians. A total of 44.1% of study infants had lumbosacral/coccygeal slate-grey patches, which were least common in Caucasians. Seven infants had coccygeal skin tags, and 14 infants had lumbosacral vascular macules. Thirty-one percent had more than 1 cutaneous lumbosacral finding present, 24.8% had 2 findings, and 6.2% had 3 or more findings. Conclusion. Coccygeal dimples, increased lumbosacral and/or coccygeal hair, deviations and/or duplications of the gluteal crease, and lumbosacral slate-grey patches are common in healthy newborns and vary by race/ethnicity. Eleven percent of study infants had 2 or more low-risk cutaneous findings excluding slate-grey patches. Distinction between low-risk and common versus high-risk findings is important when deciding which patients need further evaluation.

Occult spinal dysraphisms in newborns with skin markers: role of ultrasonography and magnetic resonance imaging

PURPOSE

The purpose of this paper is to investigate occult spinal dysraphisms (OSD) using lumbar ultrasonography (LUS) in newborns presenting with specific skin markers or sacrococcygeal dimple.

METHOD

From 2012 to 2015, we performed LUS in newborns with cutaneous stigmata and/or sacroccygeal dimple. Magnetic resonance imaging (MRI) was performed in all patients with abnormal ultrasound or features of neurological involvement in order to detect spinal lesions.

RESULTS

We prospectively evaluated 475 newborns who presented cutaneous stigmata performing LUS during their 4 weeks of life though 439 completed the study. All patients had a follow-up of almost 12 months. Of these, 39 presented abnormal ultrasonography and underwent MRI. In this group, spinal dysraphism was confirmed in 12 patients. When considering skin markers, dermal sinus correlated with higher risk of spinal cord lesions, on the other hand the presence of simple sacral dimple alone denoted a very low risk of occult spinal dysraphism. The simultaneous presence of more skin markers and/or the presence of lumbar ultrasonography abnormality regarding the level of the conus, pulsatility, and the position of the cord, thickness of the filum terminale, or the presence of an intratecal mass, lipoma, or dermal sinus tract indicated the necessity to perform MRI in order to detect spinal cord abnormalities because of higher risk of spinal lesions.

CONCLUSION

LUS in newborns with specific skin markers is a valid method to select patients in which MRI can be performed to detect OSD. The presence of a simple sacral dimple alone is a negligible marker for occult neural pathology while the presence of isolated dermal sinus or more than one cutaneous marker could be considered indicative of higher risk of spinal dysraphism.

Screening for Spinal Dysraphisms in Newborns With Sacral Dimples

Sacral dimples are common physical examination findings among newborns and are rarely associated with spinal dysraphism. Screening ultrasonography for simple sacral dimples in the absence of other physical findings leads to unnecessary health care costs and undue stress on families. This study was a retrospective chart review of infants with a sacral dimple on examination who underwent spinal ultrasonography in the first week of life. The documented indication for ultrasonography was compared to standard guidelines. Among 151 infants in the study, 80% had a normal spinal ultrasound. Of infants with abnormal ultrasonography, 7 (5%) had abnormal spinal magnetic resonance imaging and 2 infants (1%) required neurosurgical intervention. Our study revealed that nearly one-third of infants who underwent spinal ultrasonography had a simple sacral dimple and low likelihood of spinal dysraphism according to existing guidelines. Among patients who underwent spinal ultrasonography in accordance with guidelines, only a small percentage required neurosurgical intervention indicating that guidelines may need to be revised. Larger studies involving multiple centers are necessary to assess this need.

Spine ultrasounds should not be routinely performed for patients with simple sacral dimples

Primary care providers commonly obtain spine ultrasounds for neonates with simple sacral dimples due to perceived concerns about underlying spinal dysraphism, despite a lack of scientific evidence. Nine papers addressing routine spine ultrasounds for children with sacral dimples showed that 3.4% of the 5166 patients had abnormal spine ultrasounds, compared with the 4.8% reported by another study for children without sacral dimples. Most of the abnormal findings in patients with sacral dimples were of no clinical significance.

CONCLUSION

Sacral dimples do not predict underlying spinal cord malformations, and spine ultrasounds should not be performed for neonates with simple sacral dimples.

Neural tube dysraphism: review of cutaneous markers and imaging

Neural tube dysraphisms are congenital anomalies resulting from impaired formation of structures along the craniospinal axis during central nervous system development. When these malformations are large or lack a skin covering, they are easily recognized, whereas smaller or skin-covered malformations may not be readily apparent. Due to the intimate embryologic origin of the skin and nervous system, these occult malformations are often heralded by associated cutaneous abnormalities. In this article, the common clinical presentations and cutaneous markers of craniospinal dysraphism are reviewed, along with the recommended imaging modalities.

The simple sacral dimple: diagnostic yield of ultrasound in neonates

BACKGROUND

Although spinal cord tethering is known to be associated with certain clinical syndromes and cutaneous stigmata, its incidence in healthy infants with simple sacral dimples has not been thoroughly evaluated.

OBJECTIVE

Our objective was to determine the frequency of tethered cord in otherwise healthy patients with simple sacral dimples.

MATERIALS AND METHODS

We reviewed the lumbar spine US reports of all healthy neonates referred for a simple sacral dimple during a 12-year period at two children's hospitals. A sonogram was considered abnormal for a conus medullaris terminating below the L2-L3 disc space, decreased conus or nerve root motion, an abnormal filum terminale, or for the presence of an intraspinal mass, osseous dysraphism, or a sinus leading to the thecal sac. The medical records of patients with abnormal screening sonograms were reviewed to determine the final clinical outcome.

RESULTS

During the study period 3,991 infants underwent screening sonography. Of these, 107 were excluded because of the presence of other medical conditions. Of the remaining 3,884 healthy infants, 133 (3.4%) had an abnormal sonogram. Five (0.13%) of these infants were lost to follow-up; 52 subsequently had normal follow-up imaging; 49 had a low conus without other signs of tethering; 18 had a fatty filum; 2 had decreased conus motion; 2 had both a low conus and a fatty filum. None of these infants underwent surgery. Only the remaining 5/3,884 (0.13%) infants underwent surgical intervention (95% CI: 0-0.27%), and 4/5 were found to have a tethered cord intraoperatively.

CONCLUSION

The risk of significant spinal malformations in asymptomatic, healthy infants with an isolated simple sacral dimple is exceedingly low.

Intraspinal lesions associated with sacrococcygeal dimples

OBJECT.: Sacrococcygeal dimples in the gluteal fold, also known as coccygeal pits, are observed in 2%-4% of newborns. Sacrococcygeal dimples are not generally considered to be associated with a significant risk of intraspinal anomalies and therefore are not thought to require further radiographic evaluation. Accordingly, the precise incidence and nature of intraspinal lesions that may be associated with sacrococcygeal dimples is unclear. This study was conducted to determine the incidence of intraspinal lesions in patients with intergluteal dimples.

METHODS

In this study, the authors used MRI to evaluate 103 children who were seen at the Niigata University Medical and Dental Hospital between 2006 and 2011 because of skin abnormalities in the lumbosacral region. Of these children, 14 were excluded as having a subcutaneous fatty mass, and 5 were excluded because the dimples were above the gluteal fold or did not end at the coccyx. The remaining 84 patients were classified according to whether the bottom of the dimple was visible (shallow) or not (deep). The authors also retrospectively examined other skin abnormalities and coexisting anomalies.

RESULTS

The mean age at the time of MRI evaluation was 11.7 months. Magnetic resonance imaging led to the identification of fibrolipoma of the terminal filum (FTF) in 14 cases (16.7%); 6 of these patients also had a low conus. Classified by depth, there were 58 cases with shallow and 26 with deep dimples. Fibrolipoma of the terminal filum was found in significantly more patients with deep dimples (9 [34.6%]) than in those with shallow dimples (5 [8.6%]). The frequency of other congenital anomalies was significantly higher in patients with FTF-associated dimples (6 [42.9%] of 14) than in those with dimples that were not associated with FTF (9 [12.9%] of 70).

CONCLUSIONS

Fibrolipoma of the terminal filum was identified by MRI in 16.7% of patients with sacrococcygeal dimples. The risk of FTF increased when the dimples were deeply excavated or were accompanied by congenital anomalies. Magnetic resonance imaging should be performed to identify intraspinal lesions when there are high risk factors for intraspinal abnormalities, or when an ultrasound screening suggests intraspinal abnormalities.

Retethering in children after sectioning of the filum terminale

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.