Congenital lumbosacral lipomas

Prognostication of the neurological outcome of tethered cord based on intraoperative neuromonitoring findings: how close can we get?

PURPOSE

To evaluate the correlation of intraoperative neuromonitoring (IONM) data in surgery for tethered cord syndrome (TCS) in children to the neurological outcome at 1-year follow-up.

METHODS

208 consecutive patients operated on for TCS, between January 2011 to February 2020, under electrophysiological monitoring in the Division of Paediatric Neurosurgery, AIMS, Kochi, India, were included. Their preoperative neurological, urological and orthopaedic status were compared with the postoperative status at 1 year follow-up.

RESULTS

Our study prospectively collected the IONM data and retrospectively correlated it to the children's neurological outcome on follow-up. Out of 208 children, 28% (n = 59/208) had motor, 35% (n = 73/208) had bladder and 26% (n = 54/208) had bowel disturbances. Postsurgery, at one-year follow-up, 91% (n = 52/57) of the patients who had motor deficits had improvement, 82.3% (n = 51/62) of patients who had bladder deficits showed an improvement, and 88.8% (n = 48/54) with bowel deficits showed improvement. The monitorability for motor and sphincter potentials were 99.4% and 89.3%, respectively. Except for four patients (3 with bladder and 1 with motor worsening), all the patients who were monitorable with no deficits remained intact except for four patients, all the patients who had deficits and were monitorable improved after detethering (at 1 year). Clinical worsening corresponded to those who had a drop in amplitude of baseline TcMEP (n = 4). 18 events showed an increase in amplitude compared to the baseline TcMEP. These patients improved clinically on follow-up (at 1 year).

CONCLUSIONS

IONM complements the preoperative clinical details in predicting immediate and long-term outcomes.

Results of Surgical Treatment of Occult Spinal Dysraphisms-A Single Centre Experience

Occult spinal dysraphisms (OSDs) are caused by various defects in the embryogenesis of the spinal cord and represent an obstacle to the ascent of the conus, which allows the conus to pass from the lower levels of the spinal canal to the final position between L1 and L2 during normal foetal life. When an OSD tethers the spinal cord at the lower levels, it can lead to neurological symptoms, better known as tethered cord syndrome. Surgical treatment of OSD is primarily aimed at untethering the spinal cord. In asymptomatic patients, this can protect against the long-term development of neurological deficits. In symptomatic patients, this can halt or limit the progression of existing symptoms. The aim of this study is to examine all paediatric and adult patients diagnosed with OSD and treated in the Department of Neurosurgery at the University Medical Centre Ljubljana during the 5-year period of 2016-2021. All patients diagnosed with OSD during this period were included in the study. Patient characteristics, treatment modalities and outcomes were studied with the aim of describing the differences between the paediatric and adult population and defining the rationality of treating these pathological conditions. We included in the study 52 patients with 64 occult dysraphic lesions. Adults (>18 years old) represented 15/52 (28.8%) of all patients, while 37/52 (71.8%) were children. The most common OSDs were conus lipomas, followed by dermal sinus tracts, filum terminale lipomas and split cord malformations. Surgical treatment was performed in 35/52 (67.3%) cases, while conservative management was chosen in 17/52 (32.6%) cases. The preoperative presence of symptoms was statistically higher in adults than in children (p = 0.0098). Surgery on complex spinal cord lipomas was statistically related to a higher rate of postoperative neurological complications (p = 0.0002). The treatment of OSD is complex and must be based on knowledge of the developmental anomalies of the spine and spinal cord. Successful surgical treatment relies on microsurgical techniques and the use of neuromonitoring. Successful treatment can prevent or limit the occurrence of neurological problems.

Current Global Research Trends of Tethered Cord Syndrome Surgery: A Scientometric and Visual Analysis

BACKGROUND

Since tethered cord syndrome (TCS) may lead to neurologic and motor dysfunction, surgeries often are applied to relieve the symptoms. The aim of the research was to explore the current global research trends of TCS surgery.

METHODS

In this article, articles on TCS surgery in the Web of Science Core Collection from 1980 to 2023 were searched. Research trends, countries, institutions, journals, authors, highly cited articles, and key words were analyzed using bibliometric methods. The literature co-citation network was mapped using VOSviewer, and research hotspots and trends were analyzed using CiteSpace.

RESULTS

A total of 432 publications were included. The number of publications and related research interest in the field of TCS surgery has increased globally year by year. The United States is the largest contributor (154 publications). The journal Childs Nervous System has the greatest number of publications (48 publications) and the most frequently cited journal is Neurosurgery (973 citations). In network visualization, the institution with the greatest contribution is University of California System (16 publications). Lee JY and Wang KC are the authors with the greatest number of publications (8 publications), and the most frequently cited author is Klekamp J (268 citations). Neurogenic bladder and spina bifida may be the next hot spot in this field.

CONCLUSIONS

This study will help researchers to identify the mainstream research directions and the latest hotspots in the field of TCS surgery and provide a reference for further research.

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.

Chaotic lipoma with proximal syrinx -a (not so) rare variant - review of the literature, possible embryology and management

Chaotic lipomas are an extremely rare variant of spinal lipomas. This entity was first defined in 2009 by Pang and colleagues. Not much has been written about this variant. Its characteristic is the haphazard distribution of DREZ (Dorsal root entry zone), nerve roots and placode-lipoma interface. Thus complete/near-total excision of this lesion is quite difficult. We describe a case of chaotic spinal lipoma and elucidate the challenges faced in the management of this entity and review the literature. We performed a thorough systematic review with the keyword 'chaotic', 'Lipomyelomeningocele', 'Complex Lipomyelomeningocele', 'LMMC', 'Lumbar lipoma', 'spinal lipoma' in the google scholar and PUBMED data system for indexed literature on the above topic with no particular time frame. The studies quoted range earliest from 1970 till currently. Additional potential relevant articles were further retrieved through a manual search of references from original reports. Out of 42 studies, a total of 21 publications were selected which could have encountered a chaotic variant, but due to the term introduced only recently in 2009, may have been described differently. Studies encompassing true lipomeningomyelocele were excluded from our review. What we found out? Chaotic lipoma may not be a new entity. The scarce description in literature may be in part due to non-introduction and unclear description of this term earlier. The management of this variant is particularly challenging with basic principles remaining the same. Meticulous near-total excision and placode-lipoma construct are the major obstacles.

Endoscopic spinal cord untethering using a 1 cm skin incision technique in pediatrics: a technical case report

BACKGROUND

Spinal cord untethering by sectioning the filum terminale is commonly performed in tethered cord syndrome patients with minor abnormalities such as filar lipoma, thickened filum terminale, and low conus medullaris. Our endoscopic surgical technique, using the interlaminar approach, allows for sectioning the filum terminale through a very small skin incision. To our knowledge, this procedure has not been previously reported. This is the first case report involving a 1 cm skin incision.

CASE PRESENTATION

A 9-month-old male patient was referred to our neurosurgical department due to a coccygeal dimple. MRI revealed a thickened fatty filum. After considering the treatment options for this patient, the parents agreed to spinal cord untethering. A midline 1 cm skin incision was made at the L4/5 vertebral level. Untethering by sectioning the filum terminale was performed by full endoscopic surgery using the interlaminar approach. The procedure was uneventful and there were no postoperative complications.

CONCLUSIONS

In terms of visibility and minimizing invasiveness, our surgical technique of using the interlaminar approach with endoscopy allows for untethering by sectioning the filum terminale through a very small skin incision.

Surgery for spina bifida occulta: spinal lipoma and tethered spinal cord

The technical evolution of the surgery for spina bifida occulta (SBO) over the course of a half-century was reviewed with special foci placed on the spinal lipoma and tethered spinal cord. Looking back through history, SBO had been included in spina bifida (SB). Since the first surgery for spinal lipoma in the mid-nineteenth century, SBO has come to be recognized as an independent pathology in the early twentieth century. A half-century ago, the only option available for SB diagnosis was the plain X-ray, and pioneers of the time persevered in the field of surgery. The classification of spinal lipoma was first described in the early 1970s, and the concept of tethered spinal cord (TSC) was proposed in 1976. Surgical management of spinal lipoma with partial resection was the most widely practiced approach and was indicated only for symptomatic patients. After understanding TSC and tethered cord syndrome (TCS), more aggressive approaches became preferred. A PubMed search suggested that there was a dramatic increase of publications on the topic beginning around 1980. There have been immense academic achievements and technical evolutions since then. From the authors' viewpoint, landmark achievements in this field are listed as follows: (1) establishment of the concept of TSC and the understanding of TCS; (2) unraveling the process of secondary and junctional neurulation; (3) introduction of modern intraoperative neurophysiological mapping and monitoring (IONM) for surgery of spinal lipomas, especially the introduction of bulbocavernosus reflex (BCR) monitoring; (4) introduction of radical resection as a surgical technique; and (5) proposal of a new classification system of spinal lipomas based on embryonic stage. Understanding the embryonic background seems critical because different embryonic stages bring different clinical features and of course different spinal lipomas. Surgical indications and selection of surgical technique should be judged based on the background embryonic stage of the spinal lipoma. As time flows forward, technology continues to advance. Further accumulation of clinical experience and research will open the new horizon in the management of spinal lipomas and other SBO in the next half-century.

Developmental Abnormalities of the Pediatric Spine: A Review of the Correlation Between Ultrasound and MRI Findings

A broad spectrum of spinal pathologies can affect the pediatric population. Ultrasound (US) is the primary modality for pediatric spine assessment due to its widespread availability, non-requirement of sedation, and absence of ionizing radiation. Supplementing this, MRI offers an in-depth exploration of these conditions, aiding in preoperative strategizing. In this review, we examine the clinical indications, methodologies, and protocols for US and MRI scans of the pediatric spine. Additionally, we illustrate normal pediatric spinal anatomy, highlighting several examples of normal variants that are often misinterpreted. Through a series of case-based illustrations, we offer a comprehensive overview of various pathological conditions such as tethered cord, spinal dysraphism, spinal lipoma, diastematomyelia, and dermal sinus tract, among others. Furthermore, we explore the correlation between US and MRI findings for these lesions, employing real-world cases to enhance our understanding of this topic.

Motor-evoked potential monitoring from urinary sphincter muscle during pediatric untethering surgery: a case series

PURPOSE

Postoperative urinary dysfunction following untethering surgery for spinal lipoma is devastating. To assess urinary function, we invented a pediatric urinary catheter equipped with electrodes for the direct transurethral recording of myogenic potential from the external urethral sphincter (EUS). This paper presents two cases in which urinary function was monitored intraoperatively by recording of motor-evoked potential (MEP) from EUS during untethering surgery in children.

METHODS

Two children (aged 2 and 6 years) were included in this study. One patient had no preoperative neurological dysfunction, while the other had frequent urination and urinary incontinence. A pair of surface electrodes was attached to a silicone rubber urethral catheter (6 or 8 Fr; diameter, 2 or 2.6 mm). The MEP from the EUS was recorded to assess the function of the centrifugal tract from the motor cortex to the pudendal nerve.

RESULTS

Baseline MEP waveforms from the EUS were successfully recorded with latency and amplitude of 39.5 ms and 66 µV in patient 1 and 39.0 ms and 113 µV in patient 2, respectively. A significant decrease in amplitude was not observed during surgery in the two cases. No new urinary dysfunction and complications associated with the urinary catheter-equipped electrodes developed postoperatively.

CONCLUSION

Using an electrode-equipped urinary catheter, monitoring of MEP from the EUS could be applicable during untethering surgery in pediatric patients.

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.

Transition from partial to near-total/radical resection of spinal cord lipomas

PURPOSE

The objective of this retrospective study was to compare the outcomes and associated complication rates in the surgical management of spinal cord lipomas following a change of practice within our institution from partial resection (PR) to near-total/radical resection (NTR).

METHODS

Twenty-four children underwent surgical treatment for symptomatic spinal cord lipomas between 2009 and 2020. The near-total/radical resection group included 20 patients with spinal cord lipomas and the comparison group included 6 patients with spinal cord lipomas who underwent partial resection. Filar lipomas were excluded.

RESULTS

The mean age of the patients was 7 years (range 1-14 years). Post-operatively, a higher proportion of NTR patients (17/20, 85%) demonstrated improvement or stabilisation in Necker-Enfants Malades scores compared to PR patients (3/6, 50%) with a mean follow-up of 48 and 108 months respectively. Two patients underwent re-do untethering surgery, both of which initially underwent partial resection surgery. Complication rates did not significantly differ between the two groups.

CONCLUSION

Our data supports the view that near-total/radical resection should be considered the technique of choice over the conventional method of partial resection for spinal cord lipomas with no significant increase in complication rates.

Coexisting filum terminale arteriovenous fistula and filum terminale lipoma treated with single-stage surgery: illustrative case

BACKGROUND

Both filum terminale arteriovenous fistulas (FTAVFs) and filum terminale lipomas (FTLs) are rare. Because of this rarity, there is a paucity of data regarding concomitant FTAVF and FTL, and the optimal treatment remains to be defined. The authors describe a patient with coexisting FTAVF and FTL treated with single-stage surgery.

OBSERVATIONS

A man in his 70s was referred to the authors' department because of a suspected spinal vascular malformation seen on magnetic resonance imaging that was performed to investigate lower limb weakness, intermittent claudication, and urinary incontinence. Previous imaging had shown a terminal lipoma with an internal flow void. Computed tomography angiography and digital subtraction angiography revealed an FTAVF, the feeder being a lateral sacral artery. The patient was treated surgically with curative intent. The FTL and tethered cord that had been identified by imaging were treated in the same procedure. Postoperative digital subtraction angiography showed absence of the abnormal vessels. The patient was discharged home on the 19th postoperative day.

LESSONS

When considering treatment, it is important to determine whether symptoms are attributable mainly to FTL, tethered cord, or FTAVF. One-stage treatment is useful because it eliminates both the FTAVF and the factors that led to its development.

Analysis of factors affecting permanent clean intermittent catheterization and bladder function after primary neurosurgical repair of lipomyelomeningocele

AIMS

This study was conducted to identify potential risk factors for permanent clean intermittent catheterization (CIC) and incontinence in patients with lipomyelomeningocele (LMMC) and evaluate how LMMC affects bladder function prognosis, measured by urodynamic (UD) score.

METHODS

This retrospective study analyzed the electronic health records of patients who underwent primary neurosurgical repair for LMMC at a single tertiary referral center between January 2012 and December 2016 and were followed at least 3 years after surgery. Data regarding bladder function were obtained from medical records for multiple time points, including before surgery, after surgery but before hospital discharge, 3 months after surgery, and at outpatient visits during follow-up.

RESULTS

This study enrolled 120 patients. At a mean follow-up of 62.6 ± 13.9 months after primary neurosurgical LMMC repair, 22 (18.3%) patients continued to require CIC for bladder emptying, only 7 (31.8%) of whom maintained bladder continence. A multivariate logistic regression model identified age at the time of surgery and the type of LMMC as significant presurgical prognostic risk factors for permanent CIC. In addition, postoperative urinary retention and a UD score greater than or equal to 5 measured 3 months after surgery were identified as significant postsurgical risk factors for permanent CIC and urinary incontinence. A linear mixed model adjusted for age at the time of surgery showed that patients with a transitional or chaotic LMMC type were more likely to experience gradual bladder function decline than patients with other LMMC types.

CONCLUSIONS

This study identified both presurgical (age at the time of surgery, LMMC type) and postsurgical (postoperative urinary retention, UD score greater than or equal to 5 at 3 months postsurgery) risk factors for permanent CIC and urinary incontinence. In addition, LMMC type was identified as a prognostic risk factor for bladder function decline. These results will enhance the current understanding of bladder function outcomes in patients who undergo surgical treatment for LMMC.

The Current Status of the Surgical Management of Complex Spinal Cord Lipomas: Still Navigating the Labyrinth?

This review summarises the classification, anatomy and embryogenesis of complex spinal cord lipomas and describes in some detail the technique of total lipoma resection and radical reconstruction of the affected neural placode. Its specific mission is to tackle two main issues surrounding the management of complex dysraphic lipomas: whether total resection confers better long-term benefits than partial resection and whether total resection does better than conservative treatment, i.e. no surgery, for asymptomatic lipomas. Accordingly, the 24-year progression-free survival data of the senior author and colleagues' series of over 300 cases of total resection are compared with historical data from multiple series (including our own) of partial resection, and total resection data specifically for asymptomatic lesions are compared with the two known series of non-surgical treatment of equivalent patients. These comparisons so far amply support the author's recommendation of total resection for most complex lipomas, with or without symptoms. The notable exception is the asymptomatic chaotic lipoma, whose peculiar anatomical relationship with the neural tissue defies even our aggressive surgical approach, and consequently projects worse results (admittedly of small number of cases) than for the other two lipoma subtypes of dorsal and transitional lesions. Prophylactic resection of asymptomatic chaotic lipomas is therefore not currently endorsed. We have also recently found that some dorsal lipomas with clear outline of the conus on preoperative imaging had a significantly better long-term prognosis of preserving neurourological functions without surgery. Whether this subset of lipomas should be managed conservatively until symptoms arise is now an open question awaiting a longer follow-up of a larger cohort of such patients.

Updates on Intraoperative Neurophysiology During Surgery for Spinal Dysraphism

Spinal dysraphism is a group of disorders resulting from an embryologic failure of spinal cord development which can lead to a radicular-medullary mechanical stretch that generates vascular compromise and hypoxic-ischemic damage to the nervous structures of the conus-cauda region.Thus, the clinical relevance of the different types of spinal dysraphism is related to the possible neurologic deficits resulting from spinal cord tethering. The clinical presentation is heterogenous: from asymptomatic to very compromised patients. The indications and the time of a detethering surgery are still subject of debate, although there is an agreement on the high standards of treatment that have to be offered by the surgery. Intraoperative neurophysiology (ION) contributes to the safety of tethered cord surgery in reducing the risks of iatrogenic neurological damages.

Wound closure with a mesh and liquid tissue adhesive (Dermabond Prineo) system in pediatric spine surgery: a prospective single-center cohort study incorporating parent-reported outcome measures

OBJECTIVE

Wound healing can be challenging in children undergoing spine surgery for neurological conditions due to a high risk of cerebrospinal fluid (CSF) leakage and wound infection. In adults, use of the Dermabond Prineo (DP) skin closure system, which consists of both tissue adhesive glue and a self-adhesive mesh, for wound closure of medium-length surgical incisions has been reported. The aim of this study was to investigate the efficiency and cosmetic outcome of DP for wound closure in extra- and intradural pediatric neurological spine surgery.

METHODS

In this prospective cohort study, 47 children underwent 50 spine procedures using DP for wound closure between 2018 and 2022 at a single institution. Patient demographic and surgical data were collected. The primary outcome was revision surgery for wound healing disorders, while secondary outcomes were infections, minor wound healing disorders, and both physician and parental satisfaction (parent-reported outcome measures [PROMs]) at last follow-up.

RESULTS

Among 50 spinal (45 intra- and 5 extradural) interventions, 1 patient (2%) underwent revision surgery for a cutaneous CSF fistula and pseudomeningocele. Minor wound healing disorders occurred after 16 surgeries, which did not require surgical wound revision and resolved completely. No allergic reactions to DP or surgical site infections within 30 days were observed. The parents and the medical team described wound care as significantly facilitated since wound dressing changes were not needed. Three families (6.4%) encountered difficulties in wound care, and 46 (97.9%) were satisfied with DP. The cosmetic outcome based on PROMs was excellent, with a mean score of 8 (IQR 2) on a scale from 1 to 10. At long-term follow-up, a mean of 11.3 ± 10.7 months after surgery, physicians rated the cosmetic outcome on the visual analog scale (median score 9, IQR 1) and Hollander scale (median score 6, IQR 1). The outcomes were similar among the different pathologies and age groups and did not differ in patients with and without syndromic malformations.

CONCLUSIONS

The application of DP is simple, enables good patient comfort, facilitates both professional and parental wound care, and leads to excellent cosmetic results. DP possibly aids in the reduction of postoperative CSF leakage and infections after pediatric neurological spine surgery.

Electrodiagnosis has a potential to identify neural damage in asymptomatic infants with closed spinal dysraphism

PURPOSE

The presence and progression of symptoms is the basis for deciding to perform surgery in infants with closed spinal dysraphism (CSD); however, identifying symptoms could be limited, making it difficult to decide. This study investigated whether an electrodiagnostic study (EDS) can provide evidence of neural damage in asymptomatic infants with CSD.

METHODS

The study group comprised infants with CSD suspected of having neural damage based on structural abnormalities in spinal ultrasound findings. The patients' medical records were reviewed retrospectively for their clinical presentation, neuroimaging findings, urodynamic study (UDS) results, EDS findings, and surgical status.

RESULTS

Among 125 infants who underwent EDS and UDS, 117 (94%) had no clinical symptoms, except for cutaneous manifestations. Among these asymptomatic patients, 51 individuals (43.6%) had abnormal EDS findings; 33 subjects (28.2%) showed abnormal findings on EDS alone, while 37 (31.6%) on UDS alone, and 18 (15.4%) on both EDS and UDS. Chi-square test showed an opposite relationship between the two test results; when EDS was abnormal, UDS was often normal and vice versa (χ² = 5.328, p = 0.021). In all cases with abnormal EDS, denervation potentials, such as fibrillation and positive sharp waves, were observed on needle electromyography. However, abnormal findings in the nerve conduction study were observed only in six cases.

CONCLUSION

Subclinical neural damage was identified through EDS in asymptomatic infants with CSD. EDS could be necessary to determine whether follow-up monitoring only or surgical intervention is required for this patient group complementing UDS findings.

Characterizing syringomyelia and its clinical significance in 140 patients with lipomyelomeningocele

OBJECTIVE

The aims of this study were to characterize syringomyelia in patients with lipomyelomeningocele (LMMC) and investigate the association between the presence of a syrinx and patient neurological deficits.

METHODS

Patients with LMMC who had been admitted between 2007 and 2020 were included in the study. Syringomyelia on magnetic resonance imaging (MRI) was classified into three groups: true syrinx, early syrinx, and presyrinx. The correlation of clinical deficits (at birth, new onset, and progressive) and type of lipoma with the presence and type of syrinx was studied.

RESULTS

Among a total of 140 patients, the median age was 2.5 (IQR 1.3-9) years. Neurological deficits were present at birth in 75 (53.6%) patients, but 67 (47.9%) had new-onset deficits or progression of their birth deficits. The most common type of spinal lipoma was the transitional type (75.7%). Thirty-nine (27.9%) patients had a syrinx (37 with a true syrinx, 2 with an early syrinx), and 25 (17.9%) patients had a presyrinx. There was no significant correlation between the presence of a syrinx and patient neurological deficits. However, patients with a syrinx that was not adjacent to the lipoma (≥ 1 vertebral level away) had a higher incidence of deficits at birth (p = 0.045), whereas those with a syrinx spanning ≥ 5 vertebral levels had a higher incidence of progressive neurological deficits (p = 0.04). Six (75%) of 8 patients in whom serial MRI had shown syrinx progression had clinical worsening.

CONCLUSIONS

Syrinx location with respect to the spinal lipoma, syrinx length, and progressive syringomyelia may have clinical significance in patients with LMMC.

Recurrent tethering in conus lipomas: a late complication not to be ignored

BACKGROUNDS

Recurrent symptomatic tethered cord (RTC) is a long-term complication of spinal cord lipomas, responsible for progressive motor deficits, urologic dysfunction and aggravation of spinal deformities.We retrospectively analysed all cases of recurrent tethering after spinal cord lipoma surgery, the clinical and radiological features that led to the diagnosis, the surgical management and the neuro-orthopedic outcome at the last follow-up.

METHODS

The study was carried out over a period of 20 years on a total of 209 pediatric patients from a single institution, initially treated for a conus lipoma.

RESULTS

9 patients (4,8 %) were surgically treated for a RTC. The age at retethering ranged from 2 to 12 years -median of 7, 4 years. The time before the first and the second surgical procedure, ranged from 19 to 140 months - median of 7 years and a half. The follow-up period after the second surgery ranged from 3 months to 13 years with a median of 50 months. Among symptoms, pain responded very well to surgery. Gait disturbances improved in 50 % after the surgery. One patient with bladder dysfunctions also improved. The rest of the patients maintained the pre-surgical status.

CONCLUSIONS

When RTC is confirmed, child should be referred to surgery as soon as possible, as we showed that the post- operative clinical outcome improved and surgery did not worsen patients. We stressed the fact that the follow-up should be as long as possible for these patients.

Sacral Spina Bifida Occulta: A Frequency Analysis of Secular Change

Substantial relaxation of natural selection beginning around 1900 changed the mutation/selec­tion balance of modern genetic material, producing an increase in variable anatomical structures. While multiple structures have been affected, the temporal increase in variations of the sacrum, specifically, ‘Sa­cral Spina Bifida Occulta,’ have been reliably demonstrated on a localised scale. Calculation of largescale frequency has been hindered by the localised nature of these publications, the morphological variability of this variation, and potential pathological associations, which have produced divergent classifications, and conflicting reported rates of occurrence. A systematic review of the reported literature was conducted to provide an objective analysis of Sacral Spina Bifida Occulta frequency from 2500 BCE to the present. This review was designed to compensate for observed inconsistencies in reporting and to ascertain, for the first time, the temporal trajectory of this secular trend. A systematic review of Sacral Spina Bifida Occulta lit­erature was conducted through the strict use of clinical meta-analysis criteria. Publications were retrieved from four databases: PubMed, Embase, the Adelaide University Library database, and Google Scholar. Data were separated into three historical groups, (1 = <1900, 2 = 1900 to 1980 and 3 = >1980), and frequency outcomes compared, to determine temporal rates of occurrence. A total of 39/409 publications were included in the final analysis, representing data for 16,167 sacra, spanning a period of 4,500 years. Statistically significant results were obtained, with total open S1 frequen­cy increasing from 2.34%, (79 to 1900CE), to 4.80%, (1900 to 1980CE) and to 5.43% (>1980CE). These increases were significant at p<0.0001, with Chi-squared analysis. A clear secular increase in the global frequency of Sacral Spina Bifida Occulta has been demonstrated from 1900 to the present. This research provides a novel and adaptable framework for the future assessment of variation distribution, with impor­tant implications for the fields of biological anthropology and bioarchaeology.

Sacral myolipoma with involuntary contraction causing tethered cord syndrome: illustrative case

BACKGROUND

Spinal lipomas sometimes involve various ectopic tissues originating from the ectoderm, mesoderm, and endoderm in the process of morphological development.

OBSERVATIONS

A 29-year-old male patient with myolipoma of the conus medullaris at the S2 and S3 levels was described. The unusual finding, involuntary muscle contraction, was presented in an operative video and a literature review. In the present case, sacral myolipoma with involuntary contraction caused tethered cord syndrome in adulthood, and untethering surgery resolved continuous buttock and leg pain.

LESSONS

This rare finding is considered a surgical indication for adult patients with myolipoma.

Radical resection of lumbosacral lipomas in children: the Great Ormond Street Hospital experience

PURPOSE

In 2009, Pang described a radical resection technique for congenital lumbosacral lipomas, with lower long-term symptomatic re-tethering rates compared with partial resections and conservative management, and low surgical morbidity. We adopted this technique in 2011, and aim to describe our first results.

METHODS

In this monocentric retrospective audit, we included dorsal, transitional, chaotic, and caudal-type lumbosacral lipomas. Exclusion criteria were previously operated lipomas, pure filar lipomas, and concomitant major congenital anatomical urogenital/gastrointestinal abnormalities. Neuro-uro-orthopaedic status at presentation and at three months, one year and last postoperative follow-up, intraoperative electrophysiology, and extent of resection were collected.

RESULTS

From January 2011 to September 2019, 91 patients were operated (median age 2y2m; 63 transitional; 14 caudal; 8 dorsal; 6 chaotic). Preoperatively, 67% were symptomatic. Preoperative and one-year postoperative rates of impaired ambulation (44% to 43%), hypoesthesia (8% to 5%), urodynamic/uroradiological abnormalities (49% to 37%), and foot/ankle deformities (8% to 5%) were comparable, whilst pain improved (25% to 5%) but catheterisation rates increased (21% to 36%). 23/92 (25%) suffered wound-related complications. 2/91 (2%) developed symptomatic re-tethering requiring second surgery. Mean cord/sac ratio was 0.47. 43% had > 20 mm³ residual fat, which improved with increasing surgical experience.

CONCLUSION

Radical lipoma resection, guided by intraoperative neuromonitoring, with reconstruction of the neural placode and expansion duraplasty is technically feasible and results in low rates of late deterioration and re-tethering. Lipoma-type and pre-operative status are important outcome predictors. Operative risks are not insignificant. Future studies need to determine appropriate selection criteria for surgery.

Urodynamics findings pre- and post-untethering surgery in children with filum lipoma: A single-institution experience

OBJECTIVES

We aimed to investigate the changes in urodynamics and voiding cystourethrogram parameters on pre- and post-untethering surgery in patients aged under 2 years with filum lipoma.

METHODS

Sixty-two patients were enrolled in this study. The changes in urodynamics and voiding cystourethrogram parameters were compared before untethering surgery and 6 months after untethering surgery. These parameters were bladder volume, bladder deformity, vesicoureteral reflux during voiding cystourethrogram, detrusor overactivity, bladder compliance, and post-void residual volume in urodynamics.

RESULTS

Bladder volume during voiding cystourethrogram and bladder compliance increased significantly from 89.8 ± 49.5 mL to 114.5 ± 50.5 mL (P = 0.0069) and 10.2 ± 6.2 mL/mmH₂ O to 17.0 ± 13.3 mL/mmH₂ O (P = 0.0008), respectively, at 6-month follow-up. Six patients required combination management with clean intermittent catheterization at 25.1 ± 8.2 months (14.3 ± 6.5-months follow-up) because of elevated post-void residual volumes.

CONCLUSIONS

According to voiding cystourethrogram results, bladder function and urodynamics in patients with filum lipoma significantly improved after untethering surgery. Non-invasive assessment based on measurements of post-void residual should be considered as a postoperative follow-up method.

Physiological rapid growth of spinal lipoma in the early postnatal period

OBJECTIVE

Spinal lipomas are congenital malformations. They do not express tumorous growth but are found to increase in volume like other normal subcutaneous fat tissue during the early postnatal period. To understand the natural course of volume changes in spinal lipomas, the authors measured the changes in size of spinal lipomas together with the normal subcutaneous fat in relation to BMI.

METHODS

A total of 27 patients with conus spinal lipoma excluding lipomyelomeningocele who underwent MRI twice before surgery (on initial diagnosis and immediately preoperatively) were included. Patients' ages at the time of the first MRI ranged from 0 to 32 months (mean 2.9 months, median 1 month). Candidates were categorized by age into three groups: < 1 month, 1-2 months, and ≥ 3 months. The growth rate of the spinal lipomas (in three directions), change in thickness of the normal subcutaneous fat, growth rate of the normal spinal canal (dorsoventral direction), and change in BMI were retrospectively analyzed between the three groups.

RESULTS

The mean interval between MRI studies was 83.1 days. During this time, the mean lipoma growth rates were 199%, 149%, and 133% in the dorsoventral, lateral, and craniocaudal directions, respectively (with 100% representing the first measurement). The mean change in the thickness of the normal subcutaneous fat was 183%. The mean growth of the normal spinal canal was 111%. The mean increase in BMI was 124%. These rates were all significantly higher in the younger groups. There was no significant difference in the growth rates between the lipoma and the subcutaneous fat in every age group. In contrast, the growth rate of the lipoma significantly exceeded that of the spinal canal in patients younger than 3 months. The subarachnoid space around the lipoma became obstructed in 35.3%, and spinal cord distortion occurred in 48.1% of the patients younger than 3 months.

CONCLUSIONS

Spinal lipomas rapidly increase in volume before the age of 3 months and especially in infants younger than 1 month. Their features closely correlate with the physiological growth of the normal subcutaneous fat and the increase in BMI. The rapid growth of lipomas suggests the importance of close observation in this period, keeping in mind the typical anatomical changes of lipomas and their surrounding structures.

Risk factors for pre-operative functional deterioration in children with lipomyelomeningocele

PURPOSE

To characterize the temporal profile of pre-operative deterioration in children with lipomyelomeningocele (LMMC) including those with congenital deficits and identify risk factors for clinical worsening.

METHODS

Records of 87 children who underwent surgery for LMMC were retrospectively reviewed to study the temporal profile of pre-operative deterioration, defined by the onset of new neurological dysfunction or progression of a pre-existing deficit. Preoperative magnetic resonance imaging (MRI) studies were examined to identify radiological features associated with deterioration. In children with extra-spinal placodes, the angle subtended by the terminal placode with the cord at the level of the laminar-fascial defect ("J sign") was assessed.

RESULTS

Pre-operative deterioration in function was seen in 37 children (43%), occurring at a median age of 36 months and was more frequent in children without congenital deficits (54% versus 27%; p = 0.016). On Cox regression analysis, extra-spinal location of the placode (p = 0.003) and presence of a congenital deficit (p = 0.009) were positively and negatively associated with deterioration respectively. On Kaplan-Meier analysis, the median deterioration-free survival time was 72 months and was positively associated with presence of congenital deficit (p = 0.026) and negatively associated with presence of an extra-spinal placode (p < 0.001) or a meningocele sac (p = 0.001).

CONCLUSION

Extra-spinal location of the neural placode was associated with higher risk of clinical deterioration in children with LMMC, whereas the presence of a congenital deficit conferred a decreased risk. Risk stratification based on clinical and radiological features can be used to guide decisions regarding early prophylactic surgery in children with LMMC.

Mapping and monitoring of tethered cord and cauda equina surgeries

Surgery involving the cauda equina and tethered cord can be associated with significant functional disability including pain, motor and sensory deficits, as well as bladder, bowel, and sexual dysfunction. Neurophysiologic intraoperative monitoring and mapping during these surgeries using a variety of techniques and applications contributes to lessen the risk of permanent injury. This chapter reviews the anatomy of the pelvic floor, describes the techniques involved in monitoring and mapping this area, and describes the limitations of neurophysiology applications. Additionally, this chapter details mapping and monitoring techniques as they apply to tethered cord surgical release in both children and adults with review of outcome studies, and describes complications which can arise from tethered cord repair and injury to the cauda equina despite appropriate neurophysiologic intraoperative involvement.

Retethering risk in pediatric spinal lipoma of the conus medullaris

OBJECTIVE

Lipoma of the conus medullaris (LCM) causes neurological symptoms known as tethered cord syndrome (TCS). The symptoms can be seen at diagnosis and during long-term follow-up. In this report, pediatric patients with LCMs who underwent untethering surgery, under the policy of performing surgery if diagnosed regardless of symptoms, were retrospectively reviewed to evaluate long-term surgical outcomes. Possible risk factors for retethered cord syndrome (ReTCS) were evaluated in the long-term follow-up period.

METHODS

A total of 51 consecutive pediatric patients with LCMs who underwent a first untethering surgery and were followed for > 100 months were retrospectively analyzed. The surgery was performed with the partial removal technique. Pre- and postoperative clinical and radiological data were reviewed to analyze the outcomes of surgery and identify potential risk factors for ReTCS.

RESULTS

During follow-up, 12 patients experienced neurological deterioration due to ReTCS. The overall 10-year and 15-year progression-free survival rates were 82.3% and 75.1%, respectively. On univariate analysis, a lipoma type of lipomyelomeningocele (OR 11, 95% CI 2.50-48.4; p = 0.0014), patient age at the time of surgery (OR 0.41, 95% CI 0.14-1.18; p = 0.0070), and the mean patient growth rate after surgery (OR 2.00, 95% CI 1.12-3.41; p = 0.0040) were significant factors associated with ReTCS. Cox proportional hazard models showed that a lipoma type of lipomyelomeningocele (HR 5.16, 95% CI 1.54-20.1; p = 0.010) and the mean growth rate after surgery (HR 1.88, 95% CI 1.00-3.50; p = 0.040) were significantly associated with the occurrence of ReTCS.

CONCLUSIONS

More complex lesions and a high patient growth rate after surgery seemed to indicate increased risk of ReTCS. Larger prospective studies and registries are needed to define the risks of ReTCS more adequately.

Clinical and urodynamic features of secondary tethered cord syndrome: How can they be found longitudinally?

PURPOSE

Secondary tethered cord syndrome (TCS) can be diagnosed with signs of progressive deterioration in urological or neuro-orthopedic systems following primary untethering surgery. Though urological deterioration is a common secondary TCS manifestation, a paucity of diagnostic criteria makes diagnoses challenging. A detailed description of urological deterioration may help diagnose secondary TCS. Thus, the clinical and urodynamic features of the current secondary TCS cases were described.

MATERIALS AND METHODS

Fifty-one patients who had undergone reuntethering for secondary TCS experienced improvement or stabilization of progressive problems. Moreover, their clinical and videourodynamic changes were longitudinally described.

RESULTS

Loss of postoperative spontaneous voiding was the first urological secondary TCS sign for those who could void spontaneously. Urological problems mostly occurred during elementary school (6-12 years). Major urological presentations were recalcitrant urinary tract infection or urinary incontinence. Follow-up videourodynamic studies revealed typical changes, from acontractile bladder to overactive and low-complaint bladders. While detrusor overactivity did not always occur during the progression, detrusor sphincter dyssynergia was always present in all patients with urological deterioration. All patients postoperatively showed significant urodynamic improvement regardless of preoperative bladder dysfunction. This included four cases of restoring spontaneous voiding. Nine patients experienced newly appearing nonprogressive neuro-orthopedic complications despite their urological improvement.

CONCLUSIONS

Urological deterioration should prompt secondary TCS suspicion, and changes in clinical patterns and videourodynamic studies helped diagnose it. However, reuntethering can effectively address urological problems at the cost of some neuro-orthopedic functions in some patients.

Does conus morphology have implications for outcome in lumbosacral lipoma?

OBJECTIVE

Lumbosacral lipomas (LSL) of the 'dorsal' type have been associated with more favourable outcomes compared with other conus region lipomas. We hypothesised that integrity of the conus on MRI underpins the improved prognosis in this subgroup of LSL patients.

METHODS

The definition of 'dorsal lipomas' included lipomas with attachment to the conus, but where the conus could be delineated on MRI (Morota type 1) as reported by Morota et al. (J Neurosurg Pediatr 19:428-439, 2017). Additional inclusion criteria included asymptomatic status at presentation, age >3 years at follow-up, and neurological and urological evaluation at presentation and at last follow-up. Lipoma extent and conus level were recorded. Outcome measures were the need for untethering surgery and neuro-urological status at last follow-up. Urological outcomes were defined by continence and efficacy of bladder emptying.

RESULTS

Twenty-six children were included (median age 8.7 years). Conus level was low (at or below L2) in 92%. Nine required untethering surgery: 5 prophylactic, 4 because of clinical deterioration. Twenty-five children were continent at last follow-up, one had stress incontinence, and none required catheterisation. One had persisting ankle weakness after surgery requiring orthotic support.

CONCLUSIONS

In LSL of the conus, visualisation of the conus on MRI is associated with good urological and motor outcomes. The integrity of the conus appears to be a more important prognostic factor than anatomical level. An observational approach to this group of LSL patients does not appear to compromise outcomes. These findings support a selective approach to untethering surgery.

Early- and long-term surgical outcomes in 109 children with lipomyelomeningocele

AIM

To determine the functional outcomes and risk factors for outcomes following surgery for lipomyelomeningocele (LMMC).

METHODS

Data from 109 children with LMMC who underwent surgery from January 2008 to December 2017 were retrospectively studied to evaluate functional outcomes and possible risk factors for early- (at discharge from hospital or within 1 month of surgery) and long-term outcomes after surgery.

RESULTS

There were 53 boys and 56 girls with median age of 36 months (IQR 12-90 months; range, 4 months to 18 years) at surgery. At presentation, neurological function was normal (asymptomatic group) in 28 (25.7%) children while there was neurological dysfunction (symptomatic group) in 81 (74.3%). Near total or radical excision of lipoma was done in 71 (65.1%) children. Six (5.8%) children had deterioration of neurological function in the post-operative period with recovery of function in three of them. There were no statistically significant risk factors for early outcomes. At a mean follow-up of 62.5 months (IQR 35-82 months; range, 12-146 months), 21 (27.6%) of the 76 symptomatic group children (including 59.3% with incomplete bladder dysfunction) showed improvement, 52 (68.4%) remained the same, while 3 (4%) deteriorated. In 31 children (symptomatic group) who developed symptoms after 1 year of age, early surgery after development of symptoms was associated with better chances of recovery (p = 0.0008). In the asymptomatic group, 23 (88.5%) had normal neurological function at mean follow-up of 57.5 months (IQR 30-77 months; range, 12-141 months) and 3 (11.5%) had neurological deterioration. The mean time to late deterioration (re-tethering) from surgery was 51.3 months (IQR 24-75 months; range, 24-84 months). Presence of syrinx on initial MRI (p = 0.008) and partial resection of the lipoma (p = 0.02) were independent risk factors for delayed deterioration.

CONCLUSION

Radical resection of LMMC probably helps in preserving neurological function in > 90% of children at long-term follow-up. Fifty-five percent of children > 2 years of age with incomplete bladder dysfunction regained normal function following surgery. In children who develop symptoms after birth, early surgical intervention can reverse the neurological deficits.

Filum terminale lipomas-the role of intraoperative neuromonitoring

BACKGROUND

Filum terminale lipomas (FTL) represent a sub-type of spinal lipomas, where there is fatty infiltration of the filum. It becomes a surgical entity when it manifests as clinical or radiological tethered cord syndrome. Intraoperative neuromonitoring (IONM) has been suggested as a valuable tool in children for tethered cord surgeries. FTL is distinct and cannot be compared with complex tethered cord syndrome (TCS). Untethering an FTL is a relatively straightforward microsurgical exercise, usually based on anatomical findings. Neurological morbidity in FTL untethering is extremely low. The necessity of IONM in FTL has not been evaluated. The objective of this study was to identify the role of IONM in untethering an FTL METHODS: Available electronic data and case files were interrogated to identify children (0-18 years) who underwent an untethering of FTL between 2008 and 2019. We had a shift in our policy and tried to use IONM as often as possible in all tethered cord surgery from 2014. All children were categorised under 'IONM implemented' or 'no IONM' group. Outcomes analysed were as follows: (1) Clinical status on short-term and long-term follow-up, (2) alteration of surgical course by IONM and (3) complications specifically associated with IONM RESULTS: Among 80 children included in this study, IONM was implemented in 37 children and 43 children underwent untethering without IONM. 32.5% of children were 'syndromic'. Seventy-five percent of children were under age 3 years during surgery. Both groups (No IONM vs. IONM implemented) were well matched in most variables. Majority of 'no IONM' surgeries were performed prior to 2014. There was no neurological morbidity in the entire cohort. Mean duration of follow-up was 49.10 (± 33.67) months. Short-term and long-term clinical status remained stable in both cohorts. In 16 children, the filum was stimulated. Based on our protocol, majority had a negative response. One child showed a positive response, contradicted by thorough microscopic inspection. Despite a positive response, the filum was untethered. IONM was not associated with any complication in this study.

CONCLUSION

FTL untethering is an inherently low-risk microsurgery in experienced hands with rarely reported neurological morbidity. IONM may not be required for all FTL and may be used more judiciously.

Permanent Paraplegia as a Complication of Injection of Contrast Media at L2-L3 Vertebral Level

BACKGROUND

The lumbar intrathecal (subarachnoid) space is accessed for both therapeutic and diagnostic purposes. Occasionally, the needle may unintentionally enter the intrathecal space during lumbar interlaminar epidural steroid injections (LESIs)-one of the most commonly performed medical procedures in the United States. Ordinarily, this merely constitutes a minor complication or even a desired placement (in the case of some diagnostic procedures). However, some patients have a rare condition wherein the spinal cord terminates below the L2 vertebral level (tethered cord). In such cases, injections administered at the lumbar level may potentially result in spinal cord damage and irreversible paraplegia if the physician performing the intervention does not recognize the intramedullary position of the needle.

OBJECTIVE

The aim of this study is to describe and analyze an unintentional L2-L3 injection of contrast medium into a tethered spinal cord. Many physicians may consider lumbar injections "safe" because the spinal cord usually terminates at or above the L2 vertebral level. However, complacency stemming from this false impression of safety contributes to nonadherence to practice guidelines, which may lead to catastrophic neurological complications. Presented here is the first published occurrence of paraplegia that resulted from contrast medium injection into the spinal cord during a myelography study performed below the L2 vertebral level.

CONCLUSIONS

Disregard of the procedural guidelines by the physicians performing an elective diagnostic intervention may cause devastating neurological complications. The described casualty occurred because of failure to review previous imaging studies, injection of the contrast medium despite unsuccessful attempts to aspirate cerebrospinal fluid, and an unwillingness to terminate the procedure immediately when the patient reported an unusual sensation in both of his lower extremities. Consequently, we suggest that not only for cervical and thoracic but also for lumbar interlaminar ESIs, previous imaging studies should be reviewed before the injection.

Intraoperative Neuromonitoring for Tethered Cord Surgery in Infants: Challenges and Outcome

OBJECTIVE

The aim of this study was to evaluate the efficacy and safety of intraoperative neuromonitoring (IONM) in surgery for tethered cord in infants.

MATERIALS AND METHODS

The study included 87 infants who underwent surgery for closed spinal dysraphism under IONM. Their preoperative neurological and urological statuses were compared with postoperative status clinically. The study design was prospective, and the study's duration was from January 2011 to February 2020. IONM was performed (TcMEP and direct mapping) with an Xltek Protektor 32 IOM system, Natus Neurology/medical Inc., Middleton, USA. Statistical analysis in the form of χ2 is conducted using SPSS.

RESULTS

Overall, among 87 patients, clinical improvement was seen in 28 (28/29) patients with motor deficits, 17 (17/24) with bladder deficits, and 18 (18/24) with bowel deficits. The monitorability for motor and sphincter was 97.3% and 90.7%, respectively. The sensitivity of IONM in predicting new motor deficit was 100%, whereas the specificity was 100%. The negative predictive value of predicting motor deficit was 100%, with a diagnostic accuracy of 100%. There were no complications in this cohort related to the IONM.

CONCLUSIONS

The study has highlighted that the use of IONM is sensitive in identifying motor injury in infants with reliable outcome correlation. Assessment, monitoring, and outcome correlation of bladder and sphincteric functions are a challenge in this cohort.

Tethered Cord Syndrome After Myelomeningocele Repair: A Literature Update

Tethered cord syndrome (TCS) after myelomeningocele (MMC) repair (or secondary TCS) is a challenging condition characterized by neurological, orthopedic, and urological symptoms, which are combined with a low-lying position of the conus medullaris and damage to the stretched spinal cord owing to metabolic and vascular derangements. It has been reported that this syndrome affects, on average, 30% of children with MMC. In this review, we revisit the historical aspects of secondary TCS and highlight the most important concepts of diagnosis, treatment, and outcomes for secondary TCS as well as the current research regarding the impact of fetal MMC repair in the incidence and management of TCS. In the future, the development of synthetic models of TCS could shorten the learning curve of pediatric neurosurgeons, and research into the cellular proapoptotic features and increased inflammation biomarkers associated with TCS will also improve the treatment of this condition and minimize retethering of the spinal cord.

Effects of parental level of income and visual presentation of spina bifida occulta in decision making process

Background:

Parents are active participants in the referral process of children with non-life-threatening surgical pathologies. Nonetheless, there is scarce literature about the influence of parent’s level of income and perception of their children’s conditions on their decision process. Our study aims at expanding our knowledge about this parameter. We focused our research on parents of children spina bifida occulta (SBO), a condition that with a broad clinical impact and that often requires timely referral.

Methods:

Questionnaires in Mandarin were administered to parents of patients presenting to the neurosurgery clinic of a children’s hospital in Shanghai. Participants were grouped according to the level of income, above and below 50,000 Yuan. The SBO was classified into two groups, with and without evident subcutaneous mass.

Results:

One hundred and forty-five participants completed the questionnaire. Regardless of the type of lesion, families with lower income attributed their concerns for seeking care to their local physicians and the lack of health resources. Families with higher income exhibited fear of treatment. The lower income cohort presented for treatment at an older age than a higher income group. Patients with subcutaneous mass presented for treatment at a younger age than those that did not exhibit mass.

Conclusion:

Parental social economic background and visual presentation of SBO have to be factored when analyzing their decision-making process when seeking care for their children. Parental factors can be barriers to surgical care. Healthcare providers must bring parents to the forefront of the treatment process.

Expression Patterns of Hypoxia-Inducible Factors, Proinflammatory, and Neuroprotective Cytokines in Neuroepithelial Tissues of Lumbar Spinal Lipomas-A Pilot Study

OBJECTIVE

Lumbosacral lipomas (LSLs), one form of closed spinal dysraphism, are congenital disorders of the terminal spinal cord (SC). Delayed neurologic deterioration often occurs in the subsequent developmental course of the patient. Identifying the cellular and molecular factors underlying the progressive damage to neural structures is a prerequisite for developing treatment strategies for LSLs.

METHODS

Nine LSL specimens obtained from the SC/lipoma interface during surgical resection were examined. Normal SC tissue served as a control. Clinical characteristics were obtained, and spinal magnetic resonance imaging was re-evaluated. Cellular marker profiles were established. Immunoreactivity (IR) of hypoxia-inducible factor 1α (HIF-1α/-2α), erythropoietin (Epo)/erythropoietin receptor (EpoR), interleukin-1β (IL-1β)/IL-1R1, and tumor necrosis factor α/tumor necrosis factor receptor type 1 were analyzed qualitatively and semiquantitatively by densitometry. Colabeling with cellular markers was determined by multifluorescence labeling. Cytokines were further analyzed by real-time reverse transcription polymerase chain reaction.

RESULTS

LSL specimens showed significant gliosis. HIF-1α/HIF-2α-IR and Epo/Epo-IR were found at significantly higher levels in the LSL specimens, as were IL-1β-/IL-1β receptor type 1 (IL1-R1) and tumor necrosis factor α/tumor necrosis factor receptor type 1 (P < 0.001), than were the controls. At the messenger RNA level, cytokines appeared partially induced. Double immunofluorescence labeling confirmed the costaining of these factors with inflammatory and glial markers.

CONCLUSIONS

The expression of hypoxia-related and inflammatory mediators was shown for the first time in LSL specimens. These factors might play a role in multifactorial secondary lesion cascades underlying further damage to the neural placode in closed dysraphism.

Congenital Spinal Lipomatous Malformations. Part 1. Spinal Lipomas, Lipomyeloceles, and Lipomyelomeningoceles

Background: Lumbosacral spinal lipomas and lipomyeloceles are usually identified in early childhood. Terminology, histopathology, and diagnosis for these malformations can be confusing. Materials and Methods: This is a PubMed review with comparison of embryology, gross, and histopathology, and reporting requisites for these and related closed spinal malformations. Results: The spinal lipoma group (congenital spinal lipomatous malformations) includes subcutaneous, transdural, intradural, and noncontiguous malformations stretching through the entire lower spinal region. This lipomyelocele trajectory overlaps the embryonic tail's caudal eminence. Histopathologically, the lipomyelocele spectrum is a heterogeneous, stereotypical set of findings encountered from dermis to spinal cord. Diagnosis requires detailed correlation of images, intraoperative inspection, and histopathology. Conclusions: Appropriate terminology and clinicopathologic correlation to arrive at a diagnosis is a critical activity shared by pathologist and clinician. Prognostic and management differences depend on specific diagnoses. Familial and genetic influences play little if any role in patient management in closed spinal malformations.

Surgical Management of Complex Spinal Cord Lipomas : A New Perspective

This review summarises the classification, anatomy and embryogenesis of complex spinal cord lipomas, and describes in some detail the new technique of total lipoma resection and radical reconstruction of the affected neural placode. Its specific mission is to tackle two main issues surrounding the management of complex dysraphic lipomas : whether total resection confers better long term benefits than partial resection, and whether total resection does better than conservative treatment, i.e., no surgery, for asymptomatic lipomas. Accordingly, the 24 years progression-free survival data of the author and colleagues’ series of over 350 cases of total resection are compared with historical data from multiple series (including our own) of partial resection, and total resection data specifically for asymptomatic lesions are compared with the two known series of non-surgical treatment of equivalent patients. These comparisons amply support the author’s recommendation of total resection for most complex lipomas, with or without symptoms. The notable exception is the asymptomatic chaotic lipoma, whose peculiar anatomical relationship with the neural tissue defies even our aggressive surgical approach, and consequently projects worse results (admittedly of small number of cases) than for the other two lipoma subtypes of dorsal and transitional lesions. Prophylactic resection of asymptomatic chaotic lipomas is therefore not currently endorsed.

Spinal Dysraphism in the Last Two Decades : What I Have Seen during the Era of Dynamic Advancement

Compared to any other decade, the last two decades have been the most dynamic period in terms of advances in the knowledge on spinal dysraphism. Among the several factors of rapid advancement, such as embryology during secondary neurulation and intraoperative neurophysiological monitoring, there is no doubt that Professor Dachling Pang stood high amidst the period. I review here the last two decades from my personal point of view on what has been achieved in the field of spinal dysraphism, focusing on occult tethered cord syndrome, lumbosacral lipomatous malformation, terminal myelocystocele, retained medullary cord, limited dorsal myeloschisis and junctional neural tube defect. There are still many issues to revise, add and extend. Profound knowledge of basic science is critical, as well as refined clinical analysis. I expect that young scholars who follow the footsteps of precedent giants will shed bright light on this topic in the future.

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.

Structured MRI reporting in spinal dysraphism

Magnetic resonance evaluation of spinal dysraphism can be confusing for inexperienced radiologists and a detailed, step-by-step evaluation of the normal and abnormal imaging findings can help garner the diagnosis. The purpose of this article is to review the existing literature and to provide a comprehensive, structured, template checklist-style format for reporting spinal dysraphism that can help inexperienced radiologists to systematically analyze and report all the significant and ancillary findings in cases of spinal dysraphism and efficiently communicate the findings to the treating physician/surgeon.

External validation of a new classification of spinal lipomas based on embryonic stage

OBJECTIVE

Contention exists regarding appropriate classification and management of spinal lipomas (SLs). Given the heterogeneity of SLs, omissions and overlap between surgically incomparable groups exist in conventional classification systems. The new classification of spinal lipoma (NCSL) recently proposed by Morota et al. delineates morphology by embryological pathogenesis and the resultant operative difficulty. Here, the authors aimed to validate the NCSL by applying it to patients who had been operated on at their institution.

METHODS

All children who had undergone resection for SL between 2014 and 2018 were included in this analysis. MRI studies were independently reviewed and classified by three adjudicators. Baseline characteristics, inter-adjudicator agreement, coexisting anomalies and/or malformations, and postoperative outcomes and complications were analyzed.

RESULTS

Thirty-six patients underwent surgical untethering for SL: NCSL type 1 in 5 patients (14%), type 2 in 14 patients (39%), type 3 in 4 patients (11%), and type 4 in 13 patients (36%). All classification was agreed on first assignment by the adjudicators. Radical or near-radical resection, which was attempted in all patients, was always possible in those with type 1 and 4 SL, but never in those with type 2 and 3 SL. Neurological stabilization and/or improvement were observed in all patients at the last follow-up.

CONCLUSIONS

The NCSL was found to be a logical and reproducible system to apply in this SL population. All cases were successfully classified with a high degree of inter-assessor agreement. Widespread establishment of a commonly adopted and clinically useful classification system will enable clinicians to improve patient selection as well as discussion with patient representatives during the decision-making process.

Motor Evoked Potential Recordings from the Urethral Sphincter Muscles (USMEPs) during Spine Surgeries

Bowel and bladder function are at risk during tumor resection of the conus, cauda equina, and nerve roots. This study demonstrates the ability to acquire transcranial electrical motor evoked potentials (TCeMEPs) from the urethral sphincter muscles (USMEPs) by utilizing a urethral catheter with an embedded electrode. A retrospective analysis of intraoperative neurophysiological monitoring (IONM) data from nine intradural tumors, four tethered cord releases, and two spinal stenosis procedures was performed (n = 15). The cohort included seven females and eight males (median age: 38.91 years). A catheter with embedded urethral electrodes was used for recording TCeMEPs and spontaneous electromyograph (s-EMG) from the external urethral sphincter (EUS). USMEPs were obtained in 14 patients (93%). The reliability of TCeMEP from the external anal sphincter (EAS) was variable across all patients. In patient 7, the TCeMEP recordings from the urethral sphincter were not present before incision; however, following the resection of the tumor, the USMEP recordings were obtained and remained stable for the remainder of the procedure. Patient 7 had subsequent improvement in bladder function postoperatively. Patient 4 exhibited a 50% increase in the amplitude of the USMEP following tumor resection and exhibited improved bladder function as well postoperatively. In this small series, we were able to acquire consistent and reliable MEPs when recorded from the urethral sphincters. More study is needed to establish a better understanding of the value added by this modality. USMEPs can be attempted in surgeries that put the function of the pelvic floor at risk.

Predictors of surgical treatment in children with tethered fibrofatty filum terminale

OBJECTIVE

Thickened or fatty filum terminale is an occult lesion that can cause tethered cord syndrome requiring surgical untethering. This study's objectives were to estimate the incidence of tethered fibrofatty filum terminale (TFFT) in a large insured pediatric population, identify predictors of surgery among those TFFT patients, and assess a diagnostic algorithm.

METHODS

TFFT was defined according to the ICD-9-CM code for cord tethering (742.59), after excluding codes for diastematomyelia, lipomyelomeningocele, terminal myelocystocele, meningocele, and myelomeningocele. Utilizing the Optum Insight database for 2001-2014, the authors identified pediatric patients (< 21 years) in the US who were diagnosed with a tethered cord and estimated the TFFT incidence rates in that source population and the surgical untethering probability among TFFT patients over the 14-year period. Logistic regression was used to estimate the effects (adjusted OR and 95% CI) of age at diagnosis, sex, Charlson Comorbidity Index (CCI) score, diagnosis of Chiari malformation type I, diagnosis of syrinx, and the probability of surgery by US census region. Lastly, to evaluate their algorithm for identifying TFFT from ICD-9 codes, the authors estimated its positive predictive value (PPV) among 50 children who were diagnosed at their institution and met the ICD-9-CM criteria.

RESULTS

There were 3218 diagnoses of TFFT, with 482 of these pediatric patients undergoing tethered cord release during the study period. The estimated incidence rate was 12.0 per 100,000/year (95% CI 11.6-12.4 per 100,000/year). The incidence rate was slightly higher in females than in males (12.7 vs 11.4 per 100,000/year). The probability of surgery in the total pediatric TFFT population was 15.0% (95% CI 13.8%-16.2%) and was greater in children with a syrinx (OR 2.2, 95% CI 1.6-3.0), children 7-11 years of age at diagnosis versus < 1 year (OR 1.5, 95% CI 1.1-2.0), CCI score ≥ 3 versus 0 (OR 2.3, 95% CI 1.4-3.8), and residents of the Western vs Northeastern US (OR 2.3, 95% CI 1.6-3.5). In the authors' own institution's database, the PPV of TFFT was 35/50 (70.0%, 95% CI 57.3%-82.7%) for identifying tethered cord due to fibrofatty filum terminale among childhood positives.

CONCLUSIONS

Patients with comorbidities or an associated syrinx showed a higher risk of untethering procedures for TFFT. Also, surgery was appreciably more frequent in the Western US. These findings signify the need for a collaborative prospective cohort study of long-term outcomes for TFFT patients with and without surgery to determine which patients should have surgery.

Radical excision of lumbosacral lipoma: an early experience of "followers"

BACKGROUND

Indication, timing, and method for surgical treatment of lumbosacral lipoma are controversial. Radical resection of the lumbosacral lipoma and complete reconstruction of the placode are supported in that better long-term outcome can be achieved without increasing complication rate compared with traditional surgical techniques.

OBJECTIVE

We analyzed the early surgical outcomes of lumbosacral lipoma treated with the untethering and radical excision of fat.

METHODS

Retrospective analysis of surgically treated 81 fresh lumbosacral lipoma cases with dorsal, transitional, and chaotic types and true lipomyelomeningocele (LMMC) was performed. Caudal and filar types were excluded.

RESULTS

Complete untethering was accomplished in 98%. Radical excision of the lipoma was attempted in all cases and achieved in 83%. Postoperative neurological complication was observed in 8 cases (10%). Group of lipoma types (dorsal + transitional vs. chaotic + true LMMC) and availability of radical lipoma excision turn out to be factors related to neurological outcomes in univariate analysis (p < 0.001 and p = 0.027, respectively). Group of lipoma types, availability of radical excision, and postoperative cord/dural sac (C/D) ratio are related factors in multivariate analysis (p = 0.025, p = 0.049, and p = 0.031).

CONCLUSIONS

As a follower of untethering and radical excision of fat, careful consideration is required to plan the surgery of lumbosacral lipoma on account of the "underestimated" complication rate. Type of the lipoma is the important factor determining the surgical outcome. Availability of complete radical excision and postoperative C/D ratio are the operative factors related to the neurological outcomes.

Acute presentations of intradural lipomas: case reports and a review of the literature

BACKGROUND

Lumbosacral lipomas (LLs) may remain asymptomatic or lead to progressive neurological deterioration. However, sudden neurological deterioration is a rare and severe event. Herein, we report rare occurrences of sudden clinical deterioration in two previously asymptomatic children harbouring intradural LLs without dermal sinus tracts or signs of occult dysraphism. A review of the pertinent literature is also included.

CASE PRESENTATION

One child exhibited acute deterioration because of an epidural abscess associated with a filar lipoma without a sinus tract (probably caused by haematogenous spreading from a respiratory tract multiple infection), and the other child exhibited acute deterioration because of a very large, holocord syringomyelia-like cyst associated with a small conus lipoma. Both patients were 4 years old. In case #2, a previously undetected, severe tethered cord (conus at the S3-S4 level) was also present. A complete recovery was attained after an urgent surgical operation in both cases (in addition to targeted antibiotic therapy in case #1). All cases of deterioration in the literature were caused by abscess formation in dermal sinus tracts.

CONCLUSIONS

Prophylactic surgery may be indicated even in asymptomatic children that have tethered cord and surgically favourable LLs (small dorsal and filar LLs), especially if the conditions are associated with progressive syringomyelia. Similarly, intradural dermal sinus tracts should be regarded as surgery-indicated, even if the conus is in its normal position and the patient is asymptomatic because there is a consistent risk of severe, infection-related complications. Finally, asymptomatic patients with filar LLs and a normally located conus can be candidates for surgery or an accurate clinical and radiological follow-up.