Surgical treatment supposed natural history of the tethered cord with occult spinal dysraphism

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.

Does early tethered cord release in occult spinal dysraphism improve urological outcomes? A systematic review

Introduction

Occult spinal dysraphism involves a wide range of congenital anomalies, e.g., lipoma, Lipomeningomyelocele, congenital dermal sinus, etc. Occult spinal dysraphism also may present with a wide spectrum of clinical manifestations and radiological findings, i.e., it ranges from asymptomatic patients that are accidentally discovered to low lying conus with neurological, skeletal and urological manifestations. Even though neurosurgeons are well-aware of neurological presentations that indicate surgical intervention in children with occult spinal dysraphism, urological symptoms may present some controversy in management. This review aims to discuss urological outcomes of detethering as regarding time of intervention, improvement of the urological symptoms after detethering, and the role of urodynamics preoperatively and during follow-up.

Methodology

An online search of the literature was done including studies in English language from 1990 to January 2022. Included studies were analytical with well conducted descriptive nature of acceptable quality (at least level 3 evidence). Patient characteristics included both male and female children and adolescents, up to 19 years old who presented with clinical and/or radiological evidence of tethering of the spinal cord. Most studies that were included had availability of urodynamics. A total of 15 studies were included involving 633 patients. Meningomyelocele (MMC) and other spina bifida operta cases are excluded.

Results

Results of all studies were collected and mean age of studies was gathered and plotted on a chart in relation to urological outcome and urodynamic improvement. Most results favored early detethering; however, many factors were found to affect the inverse proportion curve of age with clinical improvement or urodynamics. For example, studies that included secondary tethered cord showed poorer results than results that included primary tethered cord only, preoperative severity of urological symptoms (more severe symptoms were associated with irreversible poor outcomes), and preoperative urodynamic parameters.

Conclusion

The management of tethered cord syndrome and occult spinal dysraphism remains controversial. There is lack of class 1 evidence regarding tethered cord release surgery in occult spinal dysraphism. Heterogenicity of pathology, symptomatology and radiology make the randomization of such sample size difficult. The outcomes of surgical detethering are therefore multifactorial. A large sample of prospective randomized controlled studies addressing each factor, e.g., age, severity of symptoms, preoperative urodynamic parameters, is recommended in order to evaluate the impact of each factor on outcome.

Investigating the landscape and trajectory of spina bifida research in Asia: a bibliometric analysis

BACKGROUND

Spina bifida is a type of a neural tube defect which affects 243.14 per 100,000 babies in Asia. Research articles on spina bifida have increased in the recent years. However, no study has focused on the research trends in this field in Asia.

METHODS

A systematic review of literature on spina bifida in Asia was performed using the Scopus database from inception to 2020. All published studies on spina bifida conducted in or published by authors from Asia were included in our analysis. Bibliometric information was obtained from Scopus and bibliometrics diagrams were created using VOSviewer software.

RESULTS

A total of 652 articles were obtained in this study. The number of publications showed an upward trend starting 2000s. The country with the greatest number of publications was Japan while All India Institute of Medical Sciences was the most productive institution in spina bifida research in Asia. The current focus of this field in Asia was prevalence of spina bifida, prenatal diagnosis, folic acid supplementation, and complications of spina bifida. Future areas of research in spina bifida include the genetic basis of neural tube defects and the use of stem cell technology as therapies for spina bifida.

CONCLUSION

This is the first bibliometric analysis on spina bifida in Asia. It showed the trend and future areas of research on spina bifida in Asia. Despite the increase in scientific literature on spina bifida research, more research outputs and collaborations are needed especially in developing countries in Asia.

Spinal column shortening for tethered cord syndrome: a systematic review and individual patient data meta-analysis

OBJECTIVE

Tethered cord release (TCR) is the gold standard treatment for tethered cord syndrome (TCS); however, there are significant shortcomings including high rates of retethering, especially in complex and recurrent cases. Spinal column shortening (SCS) is an alternative treatment for TCS intended to avoid these shortcomings. Early studies were limited to case reports and smaller case series; however, in recent years, larger case series and small cohort studies have been conducted. Given the increase in available data, a repeat systematic review and meta-analysis is warranted to assess the safety and efficacy of SCS for TCS.

METHODS

The authors conducted a systematic review using MEDLINE (OVID), Embase (Elsevier), and Web of Science records dating from 1944 to July 2021 to identify all articles investigating SCS for TCS. They performed standard and individual patient data (IPD) meta-analyses, with 2 independent reviewers using PRISMA-IPD guidelines. Primary outcomes were improvement of preoperative clinical symptoms of pain, motor weakness, and bladder and bowel dysfunction, and also surgical complication rate. Secondary outcomes included urodynamic improvement and health-related quality-of-life outcomes determined using patient-reported outcome tools. Individual study quality assessment was performed using a standardized assessment tool for case reports/series, and publication bias was assessed using funnel plot analyses.

RESULTS

The review yielded 15 studies with 191 cases of TCS treated with SCS. IPD were available in 11 studies with 89 cases. The average age at time of surgery was 28.0 years (range 5-76 years). The average follow-up time was 33.2 months (range 7-132 months). Improvement was observed at last follow-up in 60 of 70 (85.7%) patients with preoperative pain, in 38 of 60 (60.3%) patients with preoperative weakness, and in 36 of 76 (47.4%) patients with preoperative bladder or bowel dysfunction. Complications of CSF leak, new neurological deficit, wound infection, or reoperation occurred in 4 of 89 (4.5%) patients.

CONCLUSIONS

SCS may be considered a safe and efficacious treatment option for TCS in children and adults (level C evidence; class IIb recommendation), especially for recurrent and complex cases. Current evidence is likely to be affected by selection and publication bias. Prospective comparative studies of SCS and TCR for TCS are recommended to determine long-term duration of outcomes, long-term safety in skeletally immature children, and exact indications of SCS versus traditional TCR.

Filum Terminale: A Comprehensive Review with Anatomical, Pathological, and Surgical Considerations

The conus medullaris is the distal tapering end of the spinal cord, and the filum terminale (FT) is regarded as a bundle of non-functional fibrous tissue; therefore, some scholars call it the spinal ligament, while others describe the human FT as "remnants of the spinal cord." It was later found that in the human spinal cord, the FT is composed of an intradural segment and an epidural segment, and the end of the FT is connected to the coccyx periosteum. Because some nerve tissue is also found in the FT, as research progresses, FT may have the potential for transplantation. A lack of exhaustive overviews on the FT in the present literature prompted us to conduct this review. Considering that a current comprehensive review seemed to be the need of the hour, herein, we attempted to summarize previous research and theories on the FT, elucidate its anatomy, and understand its pathological involvement in various diseases.

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.

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.

The impact of imposed delay in elective pediatric neurosurgery: an informed hierarchy of need in the time of mass casualty crisis

SARS-CoV-2 COVID-19, coronavirus, has created unique challenges for the medical community after national guidelines called for the cancellation of all elective surgery. While there are clear cases of elective surgery (benign cranial cosmetic defect) and emergency surgery (hemorrhage, fracture, trauma, etc.), there is an unchartered middle ground in pediatric neurosurgery. Children, unlike adults, have dynamic anatomy and are still developing neural networks. Delaying seemingly elective surgery can affect a child's already vulnerable health state by further impacting their neurocognitive development, neurologic functioning, and potential long-term health states. The purpose of this paper is to demonstrate that "elective" pediatric neurosurgery should be risk-stratified, and multi-institutional informed guidelines established.

Surgical management of complex spinal cord lipomas: how, why, and when to operate. A review

This review summarizes the classification, anatomy, and embryogenesis of complex spinal cord lipomas, and it 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 fares better than conservative treatment-i.e., no surgery-for asymptomatic lipomas. Accordingly, the 24-year progression-free survival data of the author and colleagues' series of over 300 cases of total resection are compared with historical data from multiple series (including the author and colleagues' own) of partial resection, and total resection data specifically for asymptomatic lesions are compared with the two known series of nonsurgical treatment of equivalent numbers of 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 this aggressive surgical approach and consequently projects worse results (admittedly of a 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.

Long-term functional outcome after untethering surgery for a tethered spinal cord in patients with anorectal malformations

BACKGROUND

Anorectal malformation (ARM) is associated with a tethered spinal cord (TSC). Long-term functional outcome of untethering surgery for TSC in patients with ARM has not been well evaluated.

METHODS

Patients aged 7 years and older who underwent repair of ARM and spinal magnetic resonance imaging from January 1995 to December 2008 were reviewed retrospectively. Untethering surgery was performed in all patients who were diagnosed with TSC, regardless of the presence or of neurological symptoms. Clinical symptoms reflecting anorectal, urinary, and lower limb function were compared between patients complicated with TSC (TSC group, n = 17) and those without TSC (non-TSC group, n = 14).

RESULTS

The median age at functional evaluation was 11.7 and 12.9 years in the TSC and non-TSC groups, respectively (p = 0.52). Untethering surgery for TSC was performed at a median age of 1.3 years. Preoperative urinary and lower limb dysfunction, except for vesicoureteral reflux in the TSC group in one patient, was improved after surgical detethering. Current anorectal function was comparable between the groups.

CONCLUSIONS

Long-term functional outcome in patients with ARM and TSC undergoing untethering surgery is equivalent to that in those without TSC. Prophylactic surgical detethering for patients with ARM and TSC can be a treatment of choice to maximize neurological functional outcome.

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSION

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

Efficacy of electromyography and nerve conduction velocity monitoring in surgical management of terminal lipoma in children

Background: the prognosis of Terminal lipomas is better than that of other sites and pathology especially their management nowadays became clearer with better surgical outcome due to advancement of surgical tools and neurophysiology study. Objective: to assess the outcome of excision of terminal lipomyelomeningocele and reconstruction of the neural tube. Methods: From 2002 to 2016, 32 cases of terminal lipomyelomeningocele in Mansoura university hospital, insurance hospital and El Ahrar specialized center, the age of the cases ranged between 10 days and 4,3 years underwent surgical management of total or near-total lipoma excision and neural tube reformation with minimum follow up of 6 months. Results: according to system which applied to show the success of the operations, Of the 32 patients, 9 cases represent (28.1%) showed total excision of the lipoma; 17 patients represent (53.1%) had 25 mm3 of lipoma or less and 6 patients represent (18.75%) had 26 mm3 of fat or more. The neurological and urological complications was about 25%, while other complications like cerebrospinal fluid leak, wound disruption and infection was 9.4%. The surgical morbidity was comparable with the published papers. Conclusion: the excision of terminal lipomyelomeningocele and recreation of the neural tube by monitoring throughout EMG & NCV with low surgical morbidity and better results than leaving them without management or surgical interference without neurophysiological monitoring.

Spinal column shortening for tethered cord syndrome associated with myelomeningocele, lumbosacral lipoma, and lipomyelomeningocele in children and young adults

OBJECTIVE Tethered cord syndrome is the clinical manifestation of an abnormal stretch on the spinal cord, presumably causing mechanical injury, a compromised blood supply, and altered spinal cord metabolism. Tethered cord release is the standard treatment for tethered cord syndrome. However, direct untethering of the spinal cord carries potential risks, such as new neurological deficits from spinal cord injury, a CSF leak from opening the dura, and retethering of the spinal cord from normal scar formation after surgery. To avoid these risks, the authors applied spinal column shortening to children and transitional adults with primary and secondary tethered cord syndrome and report treatment outcomes. The authors' aim with this study was to determine the safety and efficacy of spinal column shortening for tethered cord syndrome by analyzing their experience with this surgical technique. METHODS The authors retrospectively reviewed the demographic and procedural data of children and young adults who had undergone spinal column shortening for primary or secondary tethered cord syndrome. RESULTS Seven patients with tethered cord syndrome caused by myelomeningocele, lipomyelomeningocele, and transitional spinal lipoma were treated with spinal column shortening. One patient with less than 24 months of follow-up was excluded from further analysis. There were 3 males and 4 females; the average age at the time was surgery was 16 years (range 8-30 years). Clinical presentations for our patients included pain (in 5 patients), weakness (in 4 patients), and bowel/bladder dysfunction (in 4 patients). Spinal column osteotomy was most commonly performed at the L-1 level, with fusion between T-12 and L-2 using a pedicle screw-rod construct. Pedicle subtraction osteotomy was performed in 6 patients, and vertebral column resection was performed in 1 patient. The average follow-up period was 31 months (range 26-37 months). Computed tomography-based radiographic outcomes showed solid fusion and no instrumentation failure in all cases by the most recent follow-up. Five of 7 patients (71%) reported improvement in preoperative symptoms during the follow-up period. The mean differences in initial and most recent Scoliosis Research Society Outcomes Questionnaire and Oswestry Disability Index scores were 0.26 and -13%, respectively; minimum clinically important difference in SRS-22 and ODI were assumed to be 0.4% and -12.8%, respectively. CONCLUSIONS Spinal column shortening seems to represent a safe and efficacious alternative to traditional untethering of the spinal cord for tethered cord syndrome.

Outcome of hospital discharge on postoperative Day 1 following uncomplicated tethered spinal cord release

OBJECTIVE Postoperative management following the release of simple spinal cord-tethering lesions is highly variable. As a quality improvement initiative, the authors aimed to determine whether an institutional protocol of discharging patients on postoperative day (POD) 1 was associated with a higher rate of postoperative CSF leaks than the prior protocol of discharge on POD 2. METHODS This was a single-center retrospective review of all children who underwent release of a spinal cord-tethering lesion that was not associated with a substantial fascial or dural defect (i.e., simple spinal cord detethering) during 2 epochs: prior to and following the institution of a protocol for discharge on POD 1. Outcomes included the need for and timing of nonroutine care of the surgical site, including return to the operating room, wound suturing, and nonsurgical evaluation and management. RESULTS Of 169 patients identified, none presented with CSF-related complications prior to discharge. In the preintervention group (n = 113), the postoperative CSF leak rate was 4.4% (5/113). The mean length of stay was 2.3 days. In the postintervention group, the postoperative CSF leak rate was 1.9% (1/53) in the patients with postdischarge follow-up. The mean length of stay in that group was 1.3 days. CONCLUSIONS At a single academic children's hospital, a protocol of discharging patients on POD 1 following uncomplicated release of a simple spinal cord-tethering lesion was not associated with an increased rate of postoperative CSF leaks, relative to the previous protocol. The rates identified are consistent with the existing literature. The authors' practice has changed to discharge on POD 1 in most cases.

Percutaneous Fully Endoscopic İnterlaminar Approach to the Filum Terminale: A Cadaveric Study

OBJECTIVE

To investigate the utility, safety, and feasibility of a novel endoscopic technique for the visualization and surgical manipulation of the filum terminale in fresh postmortem adult human cadavers.

METHODS

The filums from 18 fresh postmortem adult human cadavers were explored with a percutaneous fully endoscopic interlaminar approach. After the filum was identified and the nerve roots were dissected away from it, the filum was cut. A specimen was sent for histopathologic examination.

RESULTS

In 15 of 18 (83%) cadavers, the filum terminale could be visualized. A specimen for histopathologic examination was obtained from 11 of 15 (73%) visualized filums. Histopathologic examination revealed that 2 of them were fatty filums, 7 were normal filums, and 2 were peripheral nerves.

CONCLUSIONS

We have described a successful and feasible percutaneous fully endoscopic interlaminar approach to the filum terminale. This technique provides a smaller skin incision, narrow durotomy, and minimal tissue damage. Animal studies are necessary to prove the feasibility and safety of our method before clinical use.

Total Resection of Complex Spinal Cord Lipomas: How, Why, and When to Operate?

This article shows the long-term advantage of total resection of complex spinal cord lipomas over partial resection and over non-surgical treatment for children with asymptomatic lipomas. The classification, embryogenesis, and technique of total resection of complex lipomas are described. The 20-year outcome of 315 patients who had total resection is measured by overall progression-free survival (PFS, Kaplan-Meier), and by subgroup Cox multivariate hazard analysis for the influence of four variables: lipoma type, symptoms, prior surgery, and post-operative cord-sac ratio. These results are compared to 116 patients who underwent partial resection, and to two published series of asymptomatic lipomas followed without surgery. The PFS after total resection for all lipomas is 88.1% over 20 years vs. 34.6% for partial resection at 10.5 years (p < 0.0001). The PFS for total resection of asymptomatic virgin lipomas rose to 98.8% vs. 60% and 67% for non-surgical treatment. Partial resection also compares poorly to non-surgical treatment for asymptomatic lipomas. Multivariate analyses show that a low cord-sac ratio is the only independent variable that predicts good outcome. Pre-operative profiling shows the ideal patient for total resection is a young child with a virgin asymptomatic lipoma, who, with a PFS of 99.2%, is essentially cured. The technique of total resection can be learned by any neurosurgeon. Its long-term protection against symptomatic recurrence is better than partial resection and conservative management. The surgery should be done at diagnosis, except for asymptomatic small infants in whom surgery should be postponed till 6 months to minimize morbidity.

The effect of spinal osteotomies on spinal cord tension and dural buckling: a cadaveric study

OBJECT

The standard surgical release of a tethered cord may result in recurrent scar formation and occasionally be associated with retethering. The application of spinal shortening procedures to this challenging problem potentially can reduce tension on the retethered spinal cord while minimizing the difficulties inherent in traditional lumbosacral detethering revision. Although spinal shortening procedures have proven clinical benefit in patients with a recurrent tethered cord, it is unclear how much shortening is required to achieve adequate reduction in spinal cord tension or what impact these osteotomies have on dural buckling.

METHODS

The authors calculated mean values from 4 human cadavers to evaluate the effect of 3 different spinal shortening procedures--Smith-Petersen osteotomy (SPO), pedicle subtraction osteotomy (PSO), and vertebral column resection (VCR)--on spinal cord tension and dural buckling. Three cadavers were dedicated to the measurement of spinal cord tension, and 3 other cadavers were devoted to myelography to measure dural buckling parameters.

RESULTS

The SPO was associated with a maximal decrease in spinal cord tension of 16.1% from baseline and no dural buckling with any degree of closure. The PSO led to a mean maximal decrease in spinal cord tension of 63.1% from baseline at 12 mm of closure and demonstrated a direct linear relationship between dural buckling and increasing osteotomy closure. Finally, VCR closure correlated with a mean maximal decrease in spinal cord tension of 87.2% from baseline at 10 mm of closure and also showed a direct linear relationship between dural buckling and increases in osteotomy closure.

CONCLUSIONS

In this cadaveric experiment, the SPO did not lead to appreciable tension reduction, while a substantial response was seen with both the PSO and VCR. The rate of tension reduction may be steeper for the VCR than the PSO. Adequate tension relief while minimizing dural buckling may be optimal with 12-16 mm of posterior osteotomy closure based on this cadaveric experiment.

Neurocutaneous melanosis is associated with tethered spinal cord

PURPOSE

Neurocutaneous melanosis (NCM) is a rare congenital disorder occurring in children born with multiple or large congenital melanocytic nevi (CMN) in association with melanocytic deposits in the leptomeninges. Multiple associations between NCM and other syndromes or neurologic abnormalities have been reported. Of note, there exists a possible association between NCM and tethered cord (TC).

METHODS

We retrospectively reviewed charts and films of all patients with the diagnosis of NCM at the Children's Hospital of Pittsburgh (CHP) from August 2002 to present.

RESULTS

Five children met the criteria for NCM at our institution over a 12-year period. Apart from the melanocytic deposits, one or more additional spinal abnormalities were identified in all children. Three children had radiographic evidence of a low-lying conus medullaris, two of which also demonstrated lipomatous infiltration of the filum terminale, consistent with a tethered cord (TC).

CONCLUSIONS

Clinical features of NCM include dermatologic and neurologic manifestations. To date, this is the first series to note an association between NCM and TC. While nearly all recent series of NCM patients advocate early MRI of the neuroaxis, we recommend screening imaging of the spine on children with possible NCM regardless of the locations of CMN.

Spontaneous improvement in urological dysfunction in children with congenital spinal lipomas of the conus medullaris

Congenital spinal lipomas of the conus (SLCs) are among the most common closed neural tube defects. The treatment of SLC is an area of controversy because the true natural history of this condition is unknown. Here, the authors present two cases of SLC presenting in infancy with compromised lower urinary tract function, which was objectively confirmed by abnormal urodynamic studies. In both cases, there was spontaneous improvement in urodynamic parameters, with stable normal urinary function at the long-term follow-up. Although cases of spontaneous radiological regression of SLC have very infrequently been reported, they have not been associated with the reversal of already present neurological deficits. This report reinforces the need for further delineation of the true natural history of SLC and highlights the dynamic nature of associated neurological compromise over time.

Surgical treatment of complex spinal cord lipomas

PURPOSE

This paper shows the long-term benefits of total/near-total resection of complex spinal cord lipomas and meticulous reconstruction of the neural placode, and specifically, its advantage over partial resection, and over non-surgical treatment for the subset of children with asymptomatic virgin lipomas.

METHODS

The technique of total resection and placode reconstruction, together with technical nuances, are described in detail. We added 77 patients with complex lipomas to our original lipoma series published in 2009 and 2010, to a total of 315 patients who had had total or near-total resection and followed for a span of 20 years. Long-term outcome is measured by overall progression-free survival (PFS) with the Kaplan-Meier analysis, and by subgroup Cox proportional recurrence hazard analysis for the influence on outcome of 4 predictor variables of lipoma type, presence of symptoms, prior surgery, and post-operative cord-sac ratio. These results are compared to an age-matched, lesion-matched series of 116 patients who underwent partial lipoma resection over 11 years. The results for total resection is also compared to two large published series of asymptomatic lipomas followed without surgery over 9 to 10 years, to determine whether prophylactic total resection confers better long-term protection over conservative treatment for children with asymptomatic lipomas..

RESULTS

The PFS after total resection for all lipoma types and clinical subgroups is 88.1 % over 20 years versus 34.6 % for partial resection at 10.5 years (p < 0.0001). Culling only the asymptomatic patients with virgin (previously unoperated) lipomas, the PFS for prophylactic total resection for this subgroup rose to 98.8 % over 20 years, versus 67 % at 9 years for one group of non-surgical treatment and 60 % at 10 years for another group of conservative treatment. Our own as well as other published results of partial resection also compare poorly to non-surgical treatment for the subset of asymptomatic virgin lipomas. Multivariate subgroup analyses show that cord-sac ratio is the only independent variable that predicts outcome, with a 96.9 % PFS for ratio < 30 % (loosest sac), 86.2 % for ratio between 30 and 50 %, and 78.3 % for ratio > 50 % (tightest sac), and a threefold increase in recurrence hazard for high ratios (p = 0.0009). Pre-operative patient profiling using multiple correspondence analysis shows the ideal patient for total resection is a child less than 2 years old with a virgin asymptomatic lipoma, who, with a PFS of 99.2 %, is virtually cured by total resection.

CONCLUSION

Total/near-total resection of complex lipomas and complete reconstruction of the neural placode achieves far better long-term protection against symptomatic recurrence than partial resection for all lesions; and for the subset of asymptomatic virgin lipomas, also better than non-surgical treatment. Partial resection in many cases produces worse outcome than conservative treatment for asymptomatic lesions.

Surgical indication and outcome in patients with postoperative retethered cord syndrome

OBJECT

After untethering of spinal dysraphism, some patients present with neurological deterioration, defined as retethered cord syndrome. It is known that surgical untethering is an option for improving the symptoms of retethered cord syndrome. Previous reports have shown that postoperative improvement in retethered cord syndrome was noted in the majority of patients presenting with pain, and in more patients with motor weakness than in those with urological symptoms. The authors speculate that subjective symptoms may be detected while symptoms are still reversible. In contrast, changes in urological function are less easy to diagnose, and delays in treatment may be complicated by advanced symptoms. In this study, patients with retethered cord syndrome were evaluated to investigate the benefits of performing routine urodynamic study to detect detrusor overactivity, which is considered to be a subclinical change of urological function, and to investigate the efficacy of early untethering surgery on the symptoms of retethered cord syndrome.

METHODS

Surgical indications and outcomes of 78 untethering operations (20 for myelomeningocele, 58 for spinal lipoma) for retethered cord syndrome were examined. Diagnosis of retethered cord syndrome was defined by a multidisciplinary spina bifida team, and included routine urodynamic study.

RESULTS

Preoperative symptoms included urological symptoms (70%), lower-extremity symptoms (45%), and others. The most frequent urological symptom was detrusor overactivity detected by urodynamic study (88.7%). Urinary incontinence was only found in 9.4% of patients. Postoperatively, progressive motor weakness improved in all patients, and sensory symptoms improved in 94%. Urological symptoms improved in 80% of the patients with urinary incontinence and in 75% of the patients with detrusor overactivity. Postoperative urodynamic study showed a significant increase in bladder volume (p < 0.05). The most common complication was temporary lower leg paresthesia that recovered at follow-up. Aggravated dysuria was noted in 3 patients.

CONCLUSIONS

Early untethering operations offer symptomatic relief to patients with retethered cord syndrome. Urodynamic study findings, especially detrusor overactivity, are considered to be the most significant indicators for early diagnosis of retethered cord syndrome.

Lipomyelomeningocele: pathology, treatment, and outcomes

Lipomyelomeningocele represents a rare but complex neurological disorder that may present with neurological deterioration secondary to an inherent tethered spinal cord. Radiological testing is beneficial in determining the morphology of the malformation. Specialized testing such as urodynamic studies and neurophysiological testing may be beneficial in assessing for neurological dysfunction secondary to the lipomyelomeningocele. Early surgical intervention may be beneficial in preventing further neurological decline.

Inappropriate surgical interventions for midline fusion defects cause secondary tethered cord symptoms: implications for natural history report of four cases

INTRODUCTION

The causes of tethered spinal cord are various. In order to release the tethering effect of these malformations, the surgical interventions must include removal of all tethering components, reconstruction of the neural tube and sectioning of tight filum terminale as well.

CASES

The cases reported in this paper have had an operation many years before for various developmental defects. After a certain period of time (5-10 years) of the first operation, the patients reapplied to the hospital with various symptoms of spinal cord tethering, either vertical or horizontal.

DISCUSSION

At surgical intervention, it was noted that inappropriate surgical procedures caused retethering of the spinal cord in all patients. Postoperative period of all patients were uneventful. All patients declared relief in their symptoms. We would like to draw attention that untreated (or inappropriately treated) midline developmental defects will invariably cause syndrome of tethered cord. Consequently, prophylactic surgical untethering must be applied to all patients with developmental midline defects as soon as possible.

CONCLUSION

It looks that tethered cord symptoms invariably appear as enough negative influence accumulates as the time passes. Elapsed time may vary but unpleasant end result invariably arrives. While these cases with tethered spinal cord develop progressive neurological symptoms, prophylactic and appropriate surgical intervention should be considered as early as possible. There is no acceptable rationale to wait for the appearance of tethered cord syndrome symptoms to perform surgical untethering of the spinal cord because of the probability of irreversibility of the symptoms (incontinence of urine in particular) of tethered spinal cord syndrome.

Comparison of standard, prone and cine MRI in the evaluation of tethered cord

BACKGROUND

Tethered cord syndrome (TCS) is defined by abnormal traction on the spinal cord that confines its movement. Surgical cord release usually stops neurological deterioration; therefore, early and accurate neuroradiological diagnosis is important. Supine MRI is the imaging modality of choice, but prone MRI and cine MRI can demonstrate cord movement.

OBJECTIVE

We compared the diagnostic accuracies of standard MRI, prone MRI and cine MRI in patients with clinical suspicion of TCS and evaluated inter-reader reliability for MR imaging.

MATERIALS AND METHODS

Children who underwent MRI for suspicion of TCS were retrospectively identified. Supine, prone and cine MRI studies were re-read by two pediatric neuroradiologists. Conus level, filum appearance and cord movement were documented.

RESULTS

Thirteen of 49 children had tethered cord documented at surgery. Conus level had the highest diagnostic accuracy (sensitivity 69-77%, specificity 94%, positive predictive value 82-83%, negative predictive value 89-92%, correct diagnosis 88-90%) and highest between-reader concordance (98%). Prone and cine MRI did not add to the accuracy of the supine imaging.

CONCLUSION

Conus level provides the highest diagnostic accuracy and inter-reader reliability in TCS. Until a larger series is evaluated, it remains questionable whether prone or cine MRI provides enough additional diagnostic information to warrant routine use.

Spinal dysraphism

To review the clinical features and current understanding of spina bifida with an emphasis on the Indian Scenario. Selected articles and current English language texts were reviewed. The authors experience was also reviewed and analysed. Spina bifida is a common congenital anomaly encompassing a wide spectrum of neural tube defects.It is broadly classified as spina bifida aperta and occulta. With the prenatal screening, the incidence of aperta is gradually declining, whereas the detection of occulta has increased with the advent of magnetic resonance imaging. Over the years, the understanding of pathophysiology has made a significant changein the management of these anomalies. Early detection and complete correction can significantly reduce the neurological disability. This article is an overview of spina bifida with a special emphasis on Indian scenario.

Neurosurgical management of congenital malformations and inherited disease of the spine

Congenital malformations encompass a diverse group of disorders present at birth as result of genetic abnormalities, infection, errors of morphogenesis, or abnormalities in the intrauterine environment. Congenital disorders affecting the brain and spinal cord are often diagnosed before delivery with the use of prenatal ultrasonography and maternal serum screening. Over the past several decades there have been major advances in the understanding and management of these conditions. This article focuses on the most common spinal congenital malformations.

Symptomatic Retethering of the Spinal Cord After Section of a Tight Filum Terminale

BACKGROUND:

Section of a tight filum terminale is a minimally invasive procedure compared with cord untethering procedures used for more complex spinal abnormalities. Anecdotal evidence suggests, however, that the risk of symptomatic retethering resulting from scarring might be higher than previously thought.

OBJECTIVE:

To determine the frequency of symptomatic retethering after section of a tight filum terminale and to explore possible risk factors.

METHODS:

We reviewed databases at 2 pediatric neurosurgery centers for all patients who had surgery for a suspected tight filum terminale between January 1982 and June 2009.

RESULTS:

We identified 152 patients. The median length of follow-up was 78 months. Thirteen patients (8.6%) went on to retether symptomatically at a median time of 23.4 months after the initial procedure. Eight had early retethering (within 2 years) and 5 had late retethering (after 7 years). Compared with late retetherers, early retetherers were older at initial surgery (median, 9.4 vs 0.9 years of age), had a higher level of the conus (median, L1/L2 vs L3/L4), had more arachnoiditis after initial surgery, and required more repeat untethering procedures. Late retetherers were younger at initial surgery than those who did not retether (median, 0.9 vs 4.5 years of age).

CONCLUSION:

Symptomatic retethering is not uncommon after a simple filum snip, and long-term follow-up is warranted. Two distinct patterns of retethering were observed. Arachnoiditis caused by infection or a cerebrospinal fluid fistula may predispose to early retethering, whereas early surgery for prevention of tethered cord symptoms may predispose to late retethering.

Improved symptoms and lifestyle more than 20 years after untethering surgery for primary tethered cord syndrome

AIMS

Evaluation of the long-term effectiveness of untethering surgery on social adaptations to urinary symptoms at the time of the survey.

METHODS

Postoperative analysis of the current activities of daily life implemented as a postal questionnaire survey. Completed questionnaires were returned by 33 of 52 patients with primary tethered cord syndrome (p-TCS) who had undergone untethering surgery more than 20 years ago, including 10 patients with tight filum terminale (TFT) and 23 with cauda equina adhesion syndrome (CEAS).

RESULTS

Long-term follow-up surveys in patients with p-TCS after untethering surgery indicated excellent effects on lower urinary tract symptoms in 9 of 10 patients with TFT, and the progression of symptoms tended to improve or halted in over half of the 23 patients with CEAS. However, one patient with TFT in whom new symptoms of voiding difficulty appeared immediately after surgery and 7 with CEAS showed deterioration of urinary and/or bowel symptoms. Eighteen patients complained of some symptoms caused by lower urinary tract dysfunction after untethering surgery in terms of difficulty in activities of daily life. With the exception of one female p-TCS patient with short stature and low body weight, all data of physical status, as well as educational level, employment, occupational category and marriage statistics were within the normal respective ranges taken from the Japanese census.

CONCLUSIONS

Postoperative long-term follow-up survey in patients with p-TCS indicated significant improvement of urological symptoms. However, 55% of patients had some lower urinary tract dysfunction that affected their activities in daily life.

Tethered cord syndrome in adults

OBJECT

The treatment of tethered cord syndromes in adults is discussed regarding the natural history and surgical indications. The author analyzes data obtained in patients who were diagnosed with a tethered cord in adulthood and either underwent surgical or conservative therapy between 1991 and 2009.

METHODS

Since 1991, data obtained in 2515 patients with spinal cord pathologies were entered into the spinal cord database, and prospective follow-up was performed through outpatient visits and questionnaires. Of the 2515 patients, 85 adults with a tethered cord syndrome formed the basis of this study. The tethering effect was caused either by a split cord malformation, a thick filum terminale, a conus medullaris lipoma with extradural extension, or various combinations of these mechanisms. The mean age of the patients was 46 ± 13 years (range 23-74 years) and the mean follow-up duration was 61 ± 62 months. Two groups were distinguished based on the absence (Group A, 43 patients) or presence (Group B, 42 patients) of an associated lipoma or dysraphic cyst (that is, dermoid, epidermoid, or neurenteric cyst). Surgery was recommended for patients with symptoms only. Short-term results were determined within 3 months of surgery, whereas long-term outcomes (clinical recurrences) were evaluated using Kaplan-Meier statistics.

RESULTS

For all patients, pain was the most common major complaint. Severe neurological deficits were rare. In Group A, 20 of 43 patients underwent surgery, whereas in Group B 23 of 42 patients underwent surgery. Among individuals who did not undergo surgery, 17 patients refused surgery and 25 patients underwent recommended conservative treatment. Short-term postoperative results indicated a significant improvement of pain and a stabilization of neurological symptoms. Long-term results showed a good prognosis in patients in whom first-time (that is, nonrevision) surgery achieved successful untethering, with a 10-year rate of neurological stabilization in 89% of Group A and a 10-year rate of neurological stabilization in 81% of Group B patients. The benefit of secondary operations in Group B was limited, with eventual clinical deterioration occurring in all patients within 10 years. For patients treated conservatively, follow-up information could be obtained in 33 of 42 patients. Twenty-eight patients remained in stable clinical condition. Only 5 of the conservatively treated patients experienced clinical deterioration over time; in 4 of these individuals with deterioration, surgery had been recommended but was refused by the patient. The clinical recurrence rate in all conservatively treated patients was 21% after 10 years. With a recommendation for surgery this figure rose to 47% within 5 years.

CONCLUSIONS

Surgery in adult patients with a tethered cord syndrome should be reserved for those with symptoms. In surgically treated patients, pain relief can often be achieved, and long-term neurological stabilization tends to persist more often than it does in conservatively treated patients. A conservative approach is warranted, however, in adult patients without neurological deficits. Revision surgery in patients with complex dysraphic lesions should be performed in exceptional cases only.

Children with tethered cord syndrome of different etiology benefit from microsurgery-a single institution experience

PURPOSE

The term "tethered cord syndrome" (TCS) illustrates, according to the literature, both a separate diagnosis, as well as a combination of symptoms in the context of dysraphic conditions. The common denominator is the increased tension and abnormal stretching of the spinal cord, caused by tissue attachments that limit its movement in the spinal canal. In light of the fact that no real data exists regarding the management of these patients, the purpose of this single institutional study is to underscore management strategies and discuss the results, pitfalls, and the treatment of pediatric patients with tethered cord syndrome.

METHODS AND RESULTS

The clinical outcome in 20 pediatric patients was studied retrospectively. Ten children with closed spinal dysraphism, nine with tethering after postpartum myelomeningocele repair, and one child with an infected open dermal sinus were included. A total of 22 detethering procedures were performed. The most common symptoms prior to surgery were muscle weakness and urinary dysfunction, followed by foot deformities and pain. Of all symptoms, pain responded most favorably to surgical treatment. There was improvement in 11 out of 15 patients with preoperative motor deficits, while that was the case in 11 out of 16 patients with urinary dysfunction.

CONCLUSIONS

In view of the lack of evidence regarding the treatment of children with tethered cord syndrome, the best way to aim for a favorable outcome is correct indication for surgical intervention, combined with the implementation of technical advancements, such as intraoperative neurophysiological monitoring and ultrasound.

Spine-shortening osteotomy for patients with tethered cord syndrome caused by lipomyelomeningocele

OBJECTIVE

Tethered cord syndrome (TCS) is a disorder involving an abnormal stretching of the tethered spinal cord caused by several pathological conditions and presents with a variety of neurological symptoms. Untethering (tethered cord release) is the gold standard treatment for TCS. However, untethering carries risks of spinal cord injury and postoperative retethering. To avoid these potential risks, the authors applied spine-shortening osteotomy to adult patients with TCS, and report on the surgical procedure and treatment outcomes.

METHODS

Eight patients with TCS caused by a lipomyelomeningocele were surgically treated by the authors' original procedure of spine-shortening osteotomy. Six patients were male and 2 were females; average age at the time of surgery was 31 years old. Spine-shortening osteotomy was performed at the level of L-1 in all but 2 patients, in whom it was performed at T-12, with spinal fusion between T-12 and L-2 or T-11 and L-1 using a pedicle screw-rod system. The average follow-up period was 6.2 years and the patients' pre- and postoperative conditions were evaluated clinically and radiologically.

RESULTS

Preoperatively, all patients displayed severe neurological deficits such as motor disturbance, muscle atrophy, and bladder dysfunction. Several months before surgery, all showed progressive symptoms. Those symptoms showed initial improvement in 6 patients and stabilized in 2 postoperatively, but the improved symptoms worsened again in 4 of the 6 patients. The osteotomized vertebrae were shortened by 21 mm on average, and all spines showed complete bone union without loss of correction. At the final follow-up evaluations, 6 patients showed stabilization as per the modified Japanese Orthopaedic Association score for thoracic myelopathy.

CONCLUSIONS

Spine-shortening osteotomy successfully helps reduce the spinal cord tension without causing direct neural damage. At minimum, it stabilized the patients' symptoms and/or helped delay neurological deterioration for a period of time. Spine-shortening osteotomy might be a feasible mode of treatment for adult TCS caused by a spinal lipoma.

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

Background:

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

Methods:

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

Results:

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

Conclusion:

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

Anorectal malformations and neurospinal dysraphism: is this association a major risk for continence?

BACKGROUND/PURPOSE

Anorectal malformations (ARM) are a spectrum of defects ranging from the very minor ones, with an excellent functional prognosis, to those that are more complex, often associated with other anomalies, difficult to manage and with a poor functional outcome. A significant number of these children suffer from fecal and urinary incontinence despite major advances in the management of ARM patients have significantly improved the quality of life. The role of sacrovertebral anomalies/dysraphism (SD) and neurospinal cord anomalies/dysraphism (ND) associated with ARM on the continence of these patients is still controversial. The authors made a review of their experience in a period of 5 years, focusing on the role of neurospinal cord anomalies in patients with ARM.

MATERIALS

At colorectal clinic of our department of pediatric surgery 215 patients who underwent a procedure of posterior sagittal anorectoplasty for ARM are followed-up in a multidisciplinary clinic. Among them 60 patients with either SD or ND were documented. In 37 patients the anomaly involved the spinal cord (ND). 12 of these 37 patients underwent neurosurgical treatment and 25 were managed conservatively. Data collected from their follow-up were analyzed and compared, focusing on their bowel and urinary continence.

RESULTS

All 37 patients acquired regular bowel movements with an appropriate bowel management according to Peña's protocols. Urinary incontinence required clean intermittent catheterization in four cases. None of the patients who did not receive neurosurgical treatment developed acute complications due to the progression of the neurospinal anomaly, like acute urinary retention, orthopedic and motility problems or acute hydrocephalus. From literature review we were unable to find good evidence that the presence of ND worsens the functional prognosis of patients with ARM. We were also unable to find convincing evidence to support the practice of prophylactic neurosurgical procedures.

CONCLUSIONS

The present study supports the theory that for ARM patients the prognosis in terms of continence depends mainly on the type of malformation and is not complicated by the association with ND. In our series neurosurgical treatments did not have any effect in improving the continence of ARM patients and a conservative management of ND did not expose the patients to the sequelae of progressive deterioration, reported elsewhere, requiring rescue neurosurgery. We believe that the correct practice of pediatric surgeons following-up ARM patients is a protocol which includes appropriate investigations to detect the presence of a SD or ND and, once these entities are detected, it is mandatory to manage the patient with a multidisciplinary team, where a conservative non-operative management is initially justified and advocated in the absence of neurosensorymotor symptoms.

Reversal of longstanding neurological deficits after a late release of tethered spinal cord

The importance of early surgery for tethered cord syndrome in the pediatric population is well established. Optimal treatment and prognosis of tethered cord in adults, on the other hand, is less clear. Some advocate a conservative approach in asymptomatic patients, while others recommend early detethering in all patients. For symptomatic patients, however, there is a consensus in favor of early surgery to prevent progression of neurological deficit. Many studies have reported cessation of neurological decline or reversal of recently acquired neurological deficits in patients with adult tethered cord syndrome. There are limited data in the literature about late surgery for the treatment of tethered spinal cords when the neurological deficits are longstanding. We report on a 37-year-old woman who demonstrated dramatic neurological improvement after surgical release of a tethered spinal cord more than 20 years after the onset of progressive neurological deficits.

Tethered cord syndrome: a review of the literature from embryology to adult presentation

Tethered cord syndrome (TCS) is a clinical condition of various origins that arises from tension on the spinal cord. Radiographic findings may include the conus medullaris in a lower than normal position, fatty infiltration of the filum terminale, lipomyelomeningocele, myelomeningocele, myelocystocele, meningocele, split cord malformations, dermal sinus, anorectal malformations, and intraspinal tumors. The clinical constellation of signs and symptoms associated with TCS may include dermatologic, urological, gastrointestinal, neurological, and orthopedic findings. The current review focuses on TCS by age group of the more common causes of the condition, including myelomeningocele, lipomyelomeningocele, as well as the adult presentation of occult TCS. Pertinent review of the neuroembryology and normal anatomical position of the conus medullaris is included.

Long-Term Outcome of Total and Near-Total Resection of Spinal Cord Lipomas and Radical Reconstruction of the Neural Placode, Part II

OBJECTIVE

To show the long-term benefits of total and near-total resection of complex spinal cord lipomas and reconstruction of the neural placode.

METHODS

We analyzed 238 patients with dorsal, transitional, and chaotic lipomas who had total resection as described in part I for overall progression-free survival probability (PFS, Kaplan-Meier analysis) over 16 years. We also analyzed subgroup proportional recurrence hazard (Cox analysis) of 6 outcome predictors of sex, lipoma type, age, preoperative symptoms, previous surgery, and postoperative cord-sac ratio. These results were compared with an age-matched, lesion-matched series of 116 patients followed for 11 years after partial lipoma resection and with the Parisian series of nonsurgical treatment.

RESULTS

The immediate effects of surgery were similar between total and partial resection: both achieved greater than 95% symptom stabilization or improvement rate. The neuro-urologic complication rates for the groups were also similar, 4.2% and 5.2% for total and partial resection, respectively. The combined cerebrospinal fluid leakage and wound complication rate of total resection was much lower at 2.5% than the 6.9% for partial resection, but both were better than published rates. The overall PFS for total resection was 82.8% at 16 years, comparing much more favorably with 34.6% for partial resection at 10.5 years (P &lt; .0001). Culling only the asymptomatic patients with virgin (previously unoperated) lipomas to match the patient profile of the Parisian series, the PFS for prophylactic total resection for this subgroup increased to 98.4% at 16 years, versus 67% at 9 years for no surgery and 43.3% at 10.5 years for our own partial resection series, with a remarkable statistical difference between total and partial resection (P = .00001). Subgroup analyses showed that sex and lipoma type did not affect outcome. For the other predictor variables, while univariate analyses showed that young age, absence of symptom, and virgin lipomas correlated with better statistical PFS than older age, symptoms, and redo lipomas, these effects vanished with multivariate analyses. Cord-sac ratio stood alone as the only influential outcome predictor in multivariate analysis, with a 96.6% PFS for a low ratio of &lt;30% and an 80.6% progression-free probability for a high ratio of &gt;50%, and a 3-fold increase in recurrence hazard for high ratios (P = .0009). This suggested that all the individual effects of the other predictor variables could be reduced to whether a low cord-sac ratio could be achieved with total lipoma resection and placode reconstruction. Cord-sac ratio was the obvious factor that differentiated the outcomes between total and partial resection, the latter associated with a &gt;90% chance of having a high cord-sac ratio.

CONCLUSION

Total and near-total resection of lipomas and complete reconstruction of the neural placode produced a much better long-term progression-free probability than partial resection and nonsurgical treatment. The perioperative complications for total resection were low and compared favorably with published results. A low postoperative cord-sac ratio and well-executed placode neurulation were strongly correlated with good outcome. The ideal preoperative patient profile with early disease stabilization and the best recurrence-free probability is an asymptomatic child less than 2 years without previous lipoma surgery. There are strong indications that partial resection in many cases produces worse scarring on the neural placode and worse prognosis than no surgery.

Long-term outcome of total and near-total resection of spinal cord lipomas and radical reconstruction of the neural placode: part I-surgical technique

OBJECTIVE

Partial resection of complex spinal cord lipomas is associated with a high rate of symptomatic recurrence caused by retethering, presumably promoted by a tight content-container relationship between the spinal cord and the dural sac, and incomplete detachment of the terminal neural placode from residual lipoma. Since 1991, we have performed more than 250 total/near-total resections of complex lipomas with radical reconstruction of the neural placodes. Sixteen years of follow-up have proven the long-term benefits of this technique. Part I of this series introduces our technique of total resection and reports the immediate surgical results. Part II will analyze the long-term outcomes of both total and partial resection and identify the factors affecting outcome.

METHODS

From 1991 to 2006, 238 patients (age range, 2 months-72 years) with dorsal, transitional, and chaotic lipomas underwent total or near-total lipoma resection and radical placode reconstruction. Eighty-four percent of the patients were children younger than 18 years and 16% were adults. The technique consisted of wide bony exposure, complete unhinging of the lateral adhesions of the lipoma-placode assembly from the inner dura, untethering of the terminal conus, radical resection of the fat off the neural plate along a white fibrous plane at the cord-lipoma interface, meticulous pia-to-pia neurulation of the supple neural placode with microsutures, and expansile duraplasty with a bovine pericardial graft. Elaborate electrophysiological monitoring was used.

RESULTS

Three postoperative observations concern us. The first is that of the 238 patients, 138 (58%) had no residual fat on postoperative magnetic resonance imaging; 81 patients (36%) had less than 20 mm3 of residual fat, the majority of which were small bits enclosed by neurulation; and 19 patients (8%), mainly of the chaotic lipoma group, had more than 20 mm of fat. There are no significant differences in the amount of residual fat among lipoma types, but redo lipomas are more likely than virgin (previously unoperated on) lipomas to have residual fat by a factor of 2 (P = 0.0214). The second concern is that the state of the reconstructed placode is objectively measured by the cord-sac ratio, obtained by dividing the sagittal diameter of the reconstructed neural tube by the sagittal diameter of the thecal sac. A total of 162 patients (68%) had cord-sac ratios less than 30% (low), 61 (25.6%) had ratios between 30% and 50% (medium), and only 15 (6.3%) had high ratios of more than 50%. Seventy-four percent of patients with virgin lipomas had low cord-sac ratios compared with 56.3% in the redo lipoma patients. The overall distribution of cord-sac ratio is significantly different between redo and virgin lipomas (P = 0.00376) but not among lipoma types. Finally, the incidence of combined neurological and urological complications was 4.2%. The combined cerebrospinal fluid leak and wound infection/dehiscence incidence was 2.5%. Both sets of surgical morbidity compared favorably with the published rates reported for partial resection.

CONCLUSION

Total/near-total resection of spinal cord lipomas and complete reconstruction of the neural placode can be achieved with low surgical morbidity and a high yield of agreeable postoperative cord-sac relationship. Some large rambling transitional lipomas and most chaotic lipomas are the most difficult lesions to resect and tend to have less favorable results on postresection magnetic resonance imaging.

Rapidly regrowing lipoma in lipomeningomyelocele: a case report

INTRODUCTION

Although it is widely accepted that lipomas in lipomeningomyelocele (LMMC) are anatomically stable lesions, we present a case of rapidly growing intradural lipoma accompanied by neurological deterioration. An 8-year-old girl with rapidly regrowing LMMC was admitted to our neurosurgical clinic. She was delivered by cesarean section, and at 47 days old, she underwent detethering surgery because of aggravating weakness. We performed her detethering operation immediately rather than at 3 months as had been previously scheduled because of the rapidly growing lipoma. The second operation was performed at age 8 years because of a regrowing intradural lipoma and aggravating leg deformity. Even if LMMC is expected to be surgically corrected at 2 or 3 months after birth, lipomas could grow rapidly beyond expectation.

DISCUSSION

Close monitoring and follow-up before and after surgery is needed for optimum surgical timing, in order to avoid deteriorating neurological symptoms. The possibility of the rapid growth of intradural lipomas offers additional support for early prophylactic surgery in patients with LMMC.

CONCLUSION

The potential for rapid growth of spinal lipomas should be considered during first few months of life or even long after surgery. Early diagnosis and optimal surgery are still essential for the treatment of patients with LMMC since there is a high likelihood that residual neurological functions can be preserved.

RADIOLOGICAL FINDINGS AND CLINICAL COURSE OF CONUS LIPOMA

OBJECTIVE

A significant variety in morphology of conus lipomas may underlie differences in clinical presentation of the patients and controversy in surgical management. We retrospectively studied 58 patients with conus lipomas at our institutions. The purpose of this study was to infer the clinical course from the radiological findings and to provide information for decision-making in planning for surgical treatment.

METHODS

The patients underwent untethering surgery between 1984 and 2005. There were 35 transitional and 23 dorsal lipomas. The age at surgery ranged from 1 month to 50 years (median, 4 yr). Preoperative clinical history, radiological findings, and postoperative results were analyzed.

RESULTS

Fifteen patients were asymptomatic, and 43 patients were symptomatic preoperatively. Twenty-one patients presented with motor deficits of the lower extremities. In seven patients, motor deficits appeared early, before 1 year of age. Massive lipomas compressing the cord or herniation of the spinal cord into the subcutaneous tissue were characteristic findings of such early deterioration. Motor deficits were present in 73% of patients with lipomas extending to the lumbar level, whereas 88% of patients with lipomas confined to the sacral level had only urinary deficits. During a mean postoperative follow-up period of 7.9 years, 4 (27%) of the 15 asymptomatic patients developed urinary and/or motor deficits, and 12 (28%) of the 43 symptomatic patients showed further neurological deterioration.

CONCLUSION

This study demonstrates that the location and morphology of conus lipomas influence the neurological presentation of the patients. Early prophylactic surgery is a reasonable treatment option if early deterioration is predicted by imaging studies.

Neurogenic bladder: etiology and assessment

A review of the various causes of neurologic impairment to the lower urinary tract in children was the aim of this presentation. The emphasis was on diagnosis, pathophysiology, and treatment that strive to maintain as normal a function as possible in order to achieve eventual urinary continence and health of the upper urinary tract. The latest principles based on the most up to date evidence are promulgated but with an eye towards historical prospective. The reader should gain an adequate understanding of various disorders that comprise this condition and feel comfortable with proposing options for management when faced with the responsibility of caring for an affected child.

Tethered cord syndrome: an updated review

Tethered cord syndrome (TCS) is a diverse clinical entity characterized by symptoms and signs which are caused by excessive tension on the spinal cord. The majority of cases are related to spinal dysraphism. TCS can present in any age group, and presentations differ according to the underlying pathologic condition and age, with pain, cutaneous signs, orthopedic deformities and neurological deficits being the most common. Surgical untethering is indicated in patients with progressive or new onset symptomatology attributable to TCS. The surgical strategy aims to release the tethering structure and thus the chronic tension on the cord. Early operative intervention is associated with improved outcomes. Pain relief is accomplished in almost all cases. Realistic surgical goals include relief of pain and stabilization of neurological function, although improvement in function is often seen. Cord untethering can also halt the progression of scoliosis. The benefits of surgery are debated in asymptomatic patients and patients with normal imaging.

The effects of detethering on the urodynamics profile in children with a tethered cord

OBJECT

Tethering of the spinal cord is a pathological fixation of the cord in the vertebral column that can result in neurogenic bladder dysfunction and other neurological problems. It occurs in patients with closed spinal dysraphisms and those in whom postoperative scarring develops following spina bifida closure procedures. The authors of this study sought to determine the effects of detethering on the urodynamic profile of children with a tethered cord.

METHODS

The authors retrospectively reviewed the records of children who underwent surgical release of a tethered cord at a single institution between 2001 and 2003. They identified 17 children (nine girls and eight boys) who had undergone both preoperative and postoperative urodynamic evaluation. Preoperatively, 10 (59%) of the children with a tethered cord had abnormal urodynamic study (UDS) results. Only two (20%) of these patients had urological symptoms. All seven patients with normal preoperative UDS results had normal UDS results after detethering. In addition, in five (50%) of the 10 children with abnormal preoperative UDS results, the postoperative UDS demonstrated improved or normal urodynamics.

CONCLUSIONS

Because more than half of the children who underwent detethering were found to have abnormal preoperative UDS results, preoperative urodynamic evaluation should be performed in all cases in which detethering is considered. With regard to voiding function, detethering is relatively safe for children with normal preoperative UDS results. In children with abnormal preoperative UDS results, detethering may lead to improvement or even normalization of voiding, especially if the procedure is performed prior to 1 year of age. Finally, children with anorectal anomalies and a tethered cord may represent a subset of patients who are particularly likely to experience urodynamic improvement after detethering.

Vertebral column subtraction osteotomy for recurrent tethered cord syndrome in adults: a cadaveric study

OBJECT

The standard treatment for lumbosacral tethered cord syndrome (TCS) in adults is surgical detethering. In patients with recurrent TCS, additional detethering operations are associated with increased risk of complications and subsequent scar formation. The authors studied the effect of undertaking a vertebral column subtraction osteotomy (VCSO) at the thoracolumbar junction to shorten the vertebral column and reduce neural element tension.

METHODS

A model of TCS, developed in fresh-frozen human cadavers, was evaluated in three experiments. In Experiment 1, VCSO of 20 to 25 mm was performed at the T11-12 level. The vertebral column was sequentially shortened and the reduction in tension was measured separately in the terminal filum and the L-1 to S-3 or S-4 nerve roots. In Experiments 2 and 3 the reduction in tension was measured in the spinal cord after a VCSO and after simulating a traditional detethering operation. Vertebral column shortening produced tension reduction in all experiments. Tension decreased to less than 0.6 g in the terminal filum, L1-S3/4 nerve roots, and spinal cord after closure of a 20- to 25-mm VCSO. The mean +/- standard deviation of the deltatension/deltadistance was -0.242 +/- 0.019 g/mm for the terminal filum, -0.246 +/- 0.019 g/mm for the lumbar nerve roots, and -0.216 +/- 0.040 g/mm for the sacral nerve roots. A simulated traditional detethering operation required significant neural element release (detethering) to achieve spinal cord tension reduction equivalent to VCSO.

CONCLUSIONS

A VCSO significantly reduced neural tension at the thoracolumbar junction. This novel procedure may provide an alternative to traditional surgical detethering when scarring is excessive and the risk of complications and retethering are high.

The value of ultrasonic examination of the lumbar spine in infants with specific reference to cutaneous markers of occult spinal dysraphism

AIM

To present part of the rationale behind the recent update to the M12 guideline in The Royal College of Radiologists' publication "Making the best use of a department of clinical radiology", 4th edition 1998, which stated that ultrasound was useful in screening for dysraphism in infants with cutaneous markers such as sacral dimple or hairy patch.

MATERIALS AND METHODS

Over a 10-year period a total of 223 infant lumbar spines were scanned, for various clinical indications. Forty of these patients had already had abnormalities detected antenatally by foetal ultrasonography. One hundred and eight-three patients had abnormalities detected on postnatal clinical examination; most of these had various cutaneous markers, some had other congenital abnormalities.

RESULTS

There were a total of 29 patients with dysraphism; 24 were detected antenatally and five postnatally. Of the five, two had two or more cutaneous markers and three had anorectal anomalies. All 86 of the patients with simple sacral dimples, pits or sinuses were normal.

CONCLUSION

As an isolated abnormality, simple dimples or pits are not useful markers of spinal dysraphism. The authors suggest a new imaging protocol, resulting in improved diagnostic efficiency.

The tethered cord syndrome in adults with spina bifida occulta

The management of adult-onset tethered cord syndrome (TCA) remains controversial, although the necessity of early surgery in children with TCS is well established. In this paper, we review the major publications that discuss the congenital tethered spinal cord (spina bifida occulta) presenting in adulthood. Data concerning acquired tethered cord from prior myelomeningocele repair were excluded. TCS in adults is an uncommon entity that can become symptomatic. The long-term surgical outcome after tethered cord release in this patient population is generally favorable, as most patients report improvement or stabilization of their symptoms. In addition, the overall post-operative complication rate is low. Although special consideration should be given to older patients with a poor general medical condition, it seems reasonable to recommend early surgical treatment in both symptomatic and asymptomatic adults.

Is surgery necessary for asymptomatic tethered cord in anorectal malformation patients?

BACKGROUND

Evidence supporting routine surgery for asymptomatic tethered cord in patients with anorectal malformation (ARM) is, at best, speculative. The authors therefore examined whether untethering is indicated for asymptomatic tethered cord in patients with ARM.

METHODS

A retrospective analysis of all patients with ARM (n = 223) between 1992 and 2002 was conducted. During the same period, 435 patients had surgery for tethered cord.

RESULTS

Tethered cord was detected radiologically in 22 (9.8%); 8 patients with a low conus, and 14 with a low conus with and thickened filum. Seven of 22 patients underwent untethering; 3 prophylatic (14%) and 4 for neuro/motor function deficits (18%). All 4 symptomatic patients had significant clinical improvement in their neuro/motor functions after surgery. However, bowel and urinary functions remained unchanged in all 7 patients with a mean follow-up of 6.4 years (range, 4 to 8 years). Fifteen patients with radiologically diagnosed tethered cord remain asymptomatic with a mean follow-up of 2.7 years (range, 8 months to 10 years).

CONCLUSIONS

Neuro/motor functions clearly improved with surgery in symptomatic patients. However, bowel and urinary functions remained unchanged after surgery. Only 4 ARM patients with tethered cord required surgery, whereas prophylactic surgery appears to have minimal benefit. Expectant conservative approach in the management of asymptomatic tethered cord patient appears to be safe.