Congenital spinal lipomatous malformations: part II--Clinical presentation, operative findings, and outcome

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.

Investigating acetazolamide effectiveness on CSF leak in adult patients after spinal surgery

INTRODUCTION AND OBJECTIVES

Despite the use of acetazolamide in the management of CSF leak in most patients after CNS surgeries, there is scant evidence in the literature about the efficacy of this established protocol among adult patients in post-spinal surgery observations. We investigated the potential positive effect of acetazolamide in reducing CSF leak after spine surgery.

MATERIALS AND METHODS

We conducted a single-center, double-blind, randomized -controlled trial comparing Oral Acetazolamide plus Corrected body (prone) position (CP+A) versus Corrected body (prone) position alone (CP-A) from January 2014 to September 2015 in the Neurosurgery ward of Shariati Teaching Hospital, Tehran University of Medical Sciences, Tehran, Iran. Seventy-two Patients divided into two groups [CP-A group (n = 36, 50%) and CP+A group (n = 36, 50%)] were randomly assigned to this Clinical Trial study. CP+A group (maintained the 3/4 lateral position + dose of acetazolamide 20 mg/kg/day in 3-4 divided doses for 7 days), and CP-A group (Control group) (maintained the 3/4 lateral position for 7 days with no acetazolamide).

RESULTS

Baseline characteristics between the two groups showed no significant differences: Sex (P < .637), Age (P < .988) and previous CNS operation at other location besides the spine (P < .496). Although we reported post-surgical CSF leak in 2/36 (5.55%) of CP+A group and 4/36 (11.11%) of CP-A (control) group, there was no significant difference observed between the two groups (95%CI, 0.081-2.748; OR = 0.471; P < .402; Adjusted P < .247). Additionally, no significant differences were observed when we examined surgical characteristics, such as the size of the dural opening (P < .489) and type of operation (P < .465).

CONCLUSION

Acetazolamide has no positive effect in controlling CSF leak after dural opening/dural tear in adult patients who undergo spinal surgery, when we considered alongside the one-week prone position. Therefore, acetazolamide administration may not be essential for postoperative spinal surgery for dural tear. Prospective studies involving a larger sample size may be needed to track long-term acetazolamide complications on patients with CSF leak.

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.

A systematic review and meta-analysis of minimally invasive surgery in children with occult tethered cord syndrome

BACKGROUND

At present, the surgical treatment of occult tethered cord syndrome (OTCS) in children is mostly two types of minimally invasive surgery: filum terminalis laxity or filum terminalectomy. The clinical efficacy and safety of minimally invasive treatment and conservative treatment are still unclear. Therefore, this study will use the advantages of systematic review and meta-analysis to evaluate the objectivity, and explore the effect of minimally invasive surgery on children with occult tethered cord syndrome.

METHODS

A computer search was used to search PubMed, Embase, CNKI, Wanfang Database and other literature search websites about the randomized controlled trials (RCTs) of minimally invasive surgery in children with occult tethered cord syndrome and spinal lipoma. Professional journals were manually searched to avoid omissions. The search keywords were: occult myelolipoma, occult tethered cord syndrome, surgical treatment of tethered cord syndrome, occult tethered cord syndrome.

RESULTS

A total of 6 relevant literatures that could be used for meta-analysis were selected. A total of 425 subjects were included in the article, of which 132 were treated conservatively and 293 were treated surgically. The heterogeneity detection test statistics of the included studies were Chi² (Chi-squared test) =8.18, df (degree of freedom) =5, I²=39%<50%, Z=2.53, and the homogeneity of the included studies was good. The number of unimproved cases under conservative treatment was 40, accounting for 30.30%; the number of unimproved cases under surgical treatment was 33, accounting for 11.26%, and the total unimproved rate of the two groups accounted for 17.17%. The unimproved rate of the experimental group was significantly lower than that of the control group, and the difference was statistically significant (P=0.01). The results of bias analysis showed that there was no significant bias in the literature included in this study.

DISCUSSION

Meta-analysis results confirmed that minimally invasive surgery has a significant effect on the treatment of occult children with tethered cord syndrome. However, due to the small sample size of the included literature, further evaluation of the treatment risk is required.

Congenital Spinal Lipomatous Malformations. Part 2. Differentiation from Selected Closed Spinal Malformations

BACKGROUND

Congenital spinal lipomatous malformations (spinal lipomas, lipomyeloceles, and lipomyelomeningoceles) are closed neural tube defects over the lower back. Differentiation from some other closed neural tube defects in this region can be problematic for pathologists.

MATERIALS AND METHODS

This review is based on PubMed searches of the embryology, gross and histopathologic findings, and laboratory reporting requisites for retained medullary spinal cords, coccygeal medullary vestiges and cysts, myelocystoceles, true human vestigial tails, and pseudotails for comparison with congenital spinal lipomatous malformations.

RESULTS

Embryology, imaging, gross and histopathology of these closed neural tube lesions have different but overlapping features compared to congenital spinal lipomatous malformations, requiring context for diagnosis.

CONCLUSION

The lipomyelocele spectrum and to some degree all of the malformations discussed, even though they may not share gross appearance, anatomic site, surgical approach, or prognosis, require clinical and histopathologic correlation for final diagnosis.

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.

Minimizing CSF Leak and Wound Complications in Tethered Cord Surgery with Prone Positioning: Outcomes in 350 Patients

BACKGROUND

We document the results of a protocol to reduce the incidence of cerebrospinal fluid (CSF) leak and other wound complications in patients undergoing tethered cord surgery (TCS).

METHODS

Data from all patients undergoing TCS between January 2009 and April 2019 were reviewed retrospectively. Diagnosis (high risk or low risk; based on the presence of fascial and dural defects at surgery), type of graft used for dural or fascial repair, and CSF leak and other wound complications in the postoperative period were noted. All patients were nursed in the prone position with elevation of the foot end of the bed (Trendelenburg position) for at least 5 days after surgery with a subfascial drain in place.

RESULTS

Of a total of 350 patients (191 high risk; 159 low risk), CSF leak from the wound was noted in 16 (4.5%). All but 4 of these patients were managed with wound suturing with or without insertion of a subcutaneous drain with continued nursing in the prone and Trendelenburg position. Two patients had meningitis and 3 patients had wound infection. Multivariate analysis revealed that the use of synthetic grafts (P < 0.000) and inability to close the dura (P = 0.02) were the only significant risk factors for CSF wound leak. Wound infections and/or dehiscence were noted in 17 (4.8%) other patients.

CONCLUSION

Postoperative prone nursing with Trendelenburg position minimizes the incidence of CSF leak and other wound complications.

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.

Randomized clinical trial of acetazolamide administration and/or prone positioning in mitigating wound complications following untethering surgeries

OBJECTIVE No evidence-based guideline has been approved for the postoperative management of pediatric patients with tethered cord syndrome (TCS). The purpose of this randomized clinical trial was to evaluate the effectiveness of prone positioning and acetazolamide administration on complication rates following spinal cord untethering surgeries. METHODS From October 2012 to February 2015, patients with a primary diagnosis of TCS who were admitted to the Children's Medical Center Hospital of Iran were randomly allocated to 1 of 4 intervention modality groups postoperatively: 1) Group A, acetazolamide administration for 10 days; 2) Group B, prone positioning for 10 days; 3) Group C, acetazolamide administration and prone positioning for 10 days; and 4) Group D, no intervention. CSF leakage, CSF collection, wound dehiscence, operative site infection, and secondary surgical wound repair were considered failure. RESULTS A total of 161 patients were enrolled in this study (Group A, n = 39 [24.2%]; Group B, n = 41 [25.5%]; Group C, n = 39 [24.2%]; and Group D, n = 42 [26.1%]). The overall failure rate was 12.42% (20 patients). Complication rates through pooled analyses were as follows: CSF leakage (n = 9, 5.6%), CSF collection (n = 12, 7.5%), wound dehiscence (n = 2, 1.2%), and infection of operation site (n = 3, 1.9%). Two patients (1.2%) required surgical secondary wound repair due to complications. CSF leakage and collection rates were significantly lower in patients who underwent prone positioning (p = 0.042 and 0.036, respectively). The administration of acetazolamide, either isolated or in combination with prone positioning, not only could not significantly lower the complication rates, but also added the burden of side effects. CONCLUSIONS The current study demonstrates the possible role of prone positioning in mitigating the complication rates subsequent to untethering surgeries. Clinical trial registration no.: NCT01867268 ( clinicaltrials.gov ).

Symptomatic retethering of the spinal cord in postoperative lipomyelomeningocele patients: a meta-analysis

BACKGROUND

Timing of surgical treatment for tethered cord syndrome due to a lipomyelomeningocele (LMM) has been controversial. The purpose of this study was to evaluate populations of patients treated surgically for LMM in a meta-analysis in order to better understand how outcomes differ based on follow-up time, symptomatology, and LMM classification.

METHODS

An extensive search on PubMed and Google Scholar was performed for LMM and surgical outcomes to identify case series of patients for inclusion in this analysis. Patients were sorted based upon symptomatology prior to surgery and Chapman's LMM classification, where possible. Deterioration rates were determined by symptomatic retethering of the spinal cord that led to repeat surgery.

RESULTS

Of 608 (19 %) patients, 115 were included in the study experienced deterioration leading to repeat surgery. Symptomatic and asymptomatic patients did not experience significantly different rates of deterioration after surgical untethering. There was a significant positive linear correlation between follow-up time of studies and percentage of patients deteriorating with an increase of 3.3 % per year of follow-up. Transitional LMM had a significantly higher rate of deterioration compared to the caudal type along with the entire patient pool.

CONCLUSIONS

Outcomes of primary surgical treatment in regard to late deterioration are not significantly affected by patient symptomatology. Patient deterioration increases linearly over time. Additional studies should be performed to adequately determine the natural history of asymptomatic patients that are treated conservatively for LMM.

Schwannomatous components in a recurrent lipomyelocele: Report of a rare case

Congenital lipomatous malformations of spinal cord constitute a diverse group of lesions and lipomyelocele is one of them. Here, we report a case of congenital lipomyelocele in a male child who presented at 7 years of age. Magnetic resonance imaging (MRI) revealed a lesion in lumbosacral region. The patient was operated and histologic examination diagnosed the case to be lipomyelocele. But after 8 years, recurrence of the lesion occurred and MRI revealed the lesion at the same location. This time histologic examination detected another new component (schwannomatous areas) in the lesion. The child was on 1-year follow-up which was uneventful.

Spinal dysraphism associated with the cutaneous lumbosacral infantile hemangioma: a neuroradiological review

BACKGROUND

Spinal dysraphism is suspected in patients with midline abnormalities, especially in those with lumbosacral cutaneous markings. A recent prospective study demonstrated that isolated cutaneous infantile hemangiomas (IH) of the lumbosacral region have one of the highest risks (relative risk of 438) of associated spinal dysraphism.

OBJECTIVE

The specific types of dysraphism and radiological findings associated with cutaneous IH of the lumbosacral region have not been described in detail, to the best of our knowledge. The aim of this multicenter study is to retrospectively classify types of spinal anomalies associated with the cutaneous lumbosacral IH.

MATERIALS AND METHODS

The radiological images of 20 cases of lumbosacral infantile hemangioma associated with spinal dysraphism were reviewed.

RESULTS

Tethered cord was found in 60% of the 20 cases, spinal lipoma was present in 50% and 45% had intraspinal hemangiomas. Sinus tract was found in 40% of the children.

CONCLUSION

A range of spinal anomalies is associated with cutaneous lumbosacral infantile hemangiomas and MRI can be used to characterize these abnormalities.

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.

Surgical treatment for lipomyelomeningocele in children

BACKGROUND

Lipomyelomeningocele (LMM) is a common and severe closed neural tube defect in children. Because of the complex anatomy of LMM and the difficulty in assessing the value of surgery, the management of patients with LMM is controversial. This study was undertaken to evaluate effective techniques and procedures in surgical treatment of LMM and to assess the value of early neurosurgical intervention.

METHODS

Twenty-five children with LMM aged from 2 months to 6 years underwent surgery between January 2004 and December 2006. Magnetic resonance imaging (MRI) of the spine and electromyography (EMG) of the lower limbs was conducted in all patients preoperatively. Urodynamic studies were appropriate even in asymptomatic patients. Hoffman's functional grading was used to assess the pre and postoperative status of the patients. The operation was composed of subtotal excision of lipoma, suturing of the spinal pia mater, and section of the filum terminale. Suturing of the spinal pia mater was performed in a wide process of reconstruction of meningeal layers including the dura. Follow-up lasted 1-4 years (mean 2.1 years), in which all children underwent neurological examination, EMG and MRI.

RESULTS

After surgery a temporary neurological deterioration was found in two patients including slight weakness of a leg in one patient and urinary retention in the other, but it recovered completely a few days later. No postoperative complications were encountered. During the follow-up, 20 asymptomatic patients remained symptom-free. Symptoms disappeared totally in 2 of the 5 patients with neurological deficits, improved in one patient and stabilized in the remaining 2. MRI showed no tethered cord in all patients who underwent surgical procedures.

CONCLUSIONS

Early operation for LMM patients, even asymptomatic ones, should be performed to prevent the development of neurological deficits. Subtotal excision of lipoma, suturing of the spinal pia mater, and section of the filum terminale are recommended in the surgical treatment of LMM. The longitudinal cut of the filum terminale, a technique we have established in our surgical practice, is a simple and practical way to identify the filum terminale by visual inspection. And suturing the spinal pia mater is of extreme importance in preventing postoperative tethering.

Nontumor lesions of spinal cord and spine

Nontumor lesions of the spinal cord and spine include developmental disorders, cystic tumor-like lesions, vascular disorders, infective diseases, demyelinating diseases, degenerative diseases, metabolic and toxic disorders, and spinal cord injury. In addition, diseases of the spine and extradural spaces secondarily cause spinal cord injury. Aside from tumors, these include developmental abnormalities, inflammatory diseases, nontumor space-occupying lesions, and tumor-like lesions such as lipomas, vascular malformations, and cysts. Awareness is required of hemostatic agents used during surgery and subsequently presenting as space-occupying lesions, which have to be differentiated from recurrent lesions. On the therapeutic front, stem cell transplantation into spinal cord for treatment of neurodegenerative disorders, spinal cord injury, and multiple sclerosis is a challenging prospect.

Congenital spinal lipomatous malformations: part I--Classification

BACKGROUND

Congenital spinal lipomatous malformations constitute a diverse group of lesions. There is considerable confusion in the literature regarding their terminology and a proper classification is long overdue. The first part of this two part report sets out a proposed classification scheme.

METHODS

On the basis of this author's experience with 80 patients with a congenital spinal lipomatous malformation treated over a 10 year period, a new classification is proposed. The proposed classification divides congenital spinal lipomatous malformations into two broad groups: 1. Lipomas without dural defect and, 2. Lipomas with dural defect. Within each group, there are several subtypes. These two broad groups differ from one another in their embryology, clinical presentation, operative findings, complications and prognosis

FINDINGS

Group I consists of Lipomas without dural defect. Included in this group are: Filum lipoma, caudal lipoma without dural defect, and intramedullary lipoma. Group II consists of lipomas with dural defect. Included in this group are: dorsal lipoma, caudal lipoma with dural defect, transitional lipoma, lipomyelocele, and lipomyelomeningocele. The definitions of the various subtypes and radiological and operative findings of all these lesions are described.

CONCLUSIONS

Congenital spinal lipomatous malformations constitute a wide spectrum of lesions ranging from relatively simple lipomas of the filum terminale to complex malformations. These lesions differ from one another in their embryology, clinical presentation, operative strategies, complications and prognosis. Failure to differentiate between the different forms of congenital spinal lipomatous malformations may lead to inaccurate assumptions regarding prognosis and inappropriate management. The proposed classification seeks to address these issues.