Lumbosacral Lipomyelomeningocele

Lumbosacral Lipomyelomeningocele

Lipomyelomeningocele, is a closed neural tube defect, that usually occurs in the lumbosacral area as a single lesion but can be associated with other spinal dysraphism 1) and Caudal regression syndrome.

Represent a unique population within the spectrum of spinal dysraphism.

Premature separation of the neuroectoderm from the ipsilateral surface ectoderm allowing mesenchymal tissue to invade into the central canal, or “premature dysjunction” theory, was proposed for the pathogenesis of dorsal type lumbosacral lipoma. To test this theory, the unilateral neural fold was incised using Hamburger and Hamilton stage 12 or 13 chick embryos. Among 35 embryos evaluated, 15 showed abnormal findings, and of these one showed findings which suggested lumbosacral lipoma: a back lump, blending of the neuroepithelium and mesenchyme through indistinct basement membrane and vertebral body abnormalities. The other 14 embryos showed abnormalities including blunt tails, open neural tube defects, incomplete closure of the dorsal neuroepithelium with intact skin, skin dimples, disorganized gray matter, scoliosis, ectopic neuroepithelium and an accessory spinal cord. The results revealed that the incision of the unilateral neural fold in the early chick embryo may produce a lesion suggestive of lumbosacral lipoma, a finding which supports the premature dysjunction theory. This method needs further refinement to overcome technical difficulties, high mortality, and a low yield before being adopted as an experimental model for lumbosacral lipoma 2).

A subcutaneous lipoma that passes through a midline defect in the lumbodorsal fascia, vertebral neural arch, and dura, and merges with an abnormally low tethered cord 3).

The natural history of LMMC remains poorly defined. The description and prevalence of the presenting orthopaedic clinical signs and symptoms for LMMC have been infrequent and often documented only in general terms.

Many patients with lumbosacral lipoma are asymptomatic; however, a significant proportion will have neurological deficits present at birth and most develop neurological symptoms over time.

Implication of these deficits with respect to natural history and management are not well understood.

New dynamic MRI-based parameters to establish the presence and magnitude of tethered cord syndrome (TCS) have been defined. oscillatory frequency (OF) measured the extent of loss of translational cord displacement in supine and prone positions; delta bending angle (ΔBA) defined the relative angulation of conus with lower spinal cord, and sagittal and axial root angles represented ventral nerve root stretching. The difference in OF or ΔBA was minimum in the group with thick filum terminale and progressively increased in the groups with lipomyelomeningocele and meningomyelocele 4)

Butterfly vertebra may be associated.

Untethering surgery.

From Naidich TP, McLone DG, Mutluer S. A new understanding of dorsal dysraphism with lipoma (lipomyeloschisis): radiologic evaluation and surgical correction. AJNR. 1983; 4:103–116 5)

  1. mobilize the subcutaneous mass, it funnels down through the deep fascia

  2. open last intact vertebral arch (work from normal dura)

  3. identify the fibrovascular band that crosses the most cephalic widely bifid lamina

  4. sectioning the fibrovascular band frees the dural tube and releases the sharp kink in the superior surface of the meningocele

  5. taking care to preserve dorsal nerve roots, the dura is incised anterior to the dura-lipoma junction

  6. similar procedure is carried out with arachnoid membrane

  7. dural/arachnoid incisions are continued around entire extent of tethered conus

  8. cord and placode are untethered;

  9. Lipoma is then trimmed as completely as possible, intentionally leaving some fat behind to avoid injury to dorsal surface of placode. Superior extension along dorsal surface of cord or into central canal is debulked as much as is safely possible

  10. the placode is reformed into a closed neural tube

  11. close the pial margins

  12. the dura is closed (primarily if possible, or using fascia lata graft if too much tension is placed on folded placode)

An expansile dural graft should be incorporated in cases of lipomyelomeningocele in which primary dural closure does not permit free flow of CSF 6).

Continuous eCUSA-based stimulation of the cauda equina during LMMC resection is a feasible mapping technique with potential added value improving safety of untethering. Future studies evaluating extension of untethering, as well as the rates of retethering and long-term neurological and urological outcomes, are warranted 7).

The aim of a study is to compare the outcomes of surgical and conservative treatments of pediatric asymptomatic lumbosacral lipomas, and to address whether the patients can benefit from prophylactic surgeries. The literature reports of surgical and conservative treatments of child asymptomatic lumbosacral lipomas were reviewed and collected, and a meta-analysis of the reports regarding the incidence of sphincter and lower limb dysfunctions was performed. A total of five literatures were collected, containing a total of 403 patients, among which 124 patients received conservative treatments with 32 (25.81%) cases developing neurological dysfunctions during follow-up, and 279 received prophylactic surgical treatments with 30 (10.75%) patients developing neurological dysfunctions in follow-up, the difference being statistically significant (P ≤ 0.05). For pediatric asymptomatic lumbosacral lipomas of the three major subtypes, the limited source of literature so far suggests that prophylactic surgery is superior to conservative strategy in preventing the patients from neurological deterioration. Larger patient cohorts, randomized studies, and longer length of follow-ups are needed for further corroboration 8).

Lumbosacral lipomyelomeningocele case series.

Lumbosacral Lipomyelomeningocele with Lateral Attachment to Neural Placode 9).

Fetal lipomyelomeningocele was suspected during the second-trimester ultrasound and confirmed by magnetic resonance imaging. The pregnancy took its course and a term neonate was delivered. At 2 years of age lipomyelomeningocele surgical removal was performed. The patient is now 4 years old and, despite neurogenic bladder, is a healthy boy with normal psychomotor development for his age. This case illustrates the favorable prognosis of this entity and the importance of prompt diagnosis and multidisciplinary counseling 10).

A patient with lipomyelomeningocele (known in utero) presented for MRI characterization prior to surgical procedure at three months of age. Cross-sectional imaging revealed a spinal dysraphism of the lower lumbar spine, with a posterior spinal defect spanning L4 to S2 subcutaneous fat intrusion, and distal spinal cord extrusion. An osseous excrescence was also appreciated, articulating with the left iliac bone. This case demonstrates the youngest known lipomyelomeningocele with accessory limb and the abnormal growth of multiple tissue types at the site of spinal dysraphism-a potential consequence of dedifferentiated cell proliferation originating from a secondary neural tube defect or rachipagus parasitic twinning 11)


Hanif H, Khanbabazadeh S, Nejat F, El Khashab M. Tethered cord with tandem lipomyelomeningoceles, split cord malformation and thick filum. J Pediatr Neurosci. 2013 Sep;8(3):204-6. doi: 10.4103/1817-1745.123665. PubMed PMID: 24470813.

Li YC, Shin SH, Cho BK, Lee MS, Lee YJ, Hong SK, Wang KC. Pathogenesis of lumbosacral lipoma: a test of the “premature dysjunction” theory. Pediatr Neurosurg. 2001 Mar;34(3):124-30. PubMed PMID: 11359100.

Emery JL, Lendon RG. Lipomas of the Cauda Equina and Other Fatty Tumors Related to Neurospinal Dysraphism.DevMedChildNeurol.1969;11:62–70

Singh S, Behari S, Singh V, Bhaisora KS, Haldar R, Krishna Kumar G, Mishra P, Phadke RV. Dynamic magnetic resonance imaging parameters for objective assessment of the magnitude of tethered cord syndrome in patients with spinal dysraphism. Acta Neurochir (Wien). 2018 Nov 20. doi: 10.1007/s00701-018-3721-7. [Epub ahead of print] PubMed PMID: 30456429.

Naidich TP, McLone DG, Mutluer S. A new understanding of dorsal dysraphism with lipoma (lipomyeloschisis): radiologic evaluation and surgical correction. AJNR. 1983; 4:103–116

Alexiades NG, Ahn ES, Blount JP, Brockmeyer DL, Browd SR, Grant GA, Heuer GG, Hankinson TC, Iskandar BJ, Jea A, Krieger MD, Leonard JR, Limbrick DD Jr, Maher CO, Proctor MR, Sandberg DI, Wellons JC 3rd, Shao B, Feldstein NA, Anderson RCE. Development of best practices to minimize wound complications after complex tethered spinal cord surgery: a modified Delphi study. J Neurosurg Pediatr. 2018 Sep 14:1-9. doi: 10.3171/2018.6.PEDS18243. [Epub ahead of print] PubMed PMID: 30215584.

Sapir Y, Buzaglo N, Korn A, Constantini S, Roth J, Rochkind S. Dynamic mapping using an electrified ultrasonic aspirator in lipomyelomeningocele and spinal cord detethering surgery-a feasibility study. Childs Nerv Syst. 2021 Jan 6. doi: 10.1007/s00381-020-05012-8. Epub ahead of print. PMID: 33404721.

Xiong Y, Yang L, Zhen W, Fangyong D, Feng W, Ting L. Conservative and surgical treatment of pediatric asymptomatic lumbosacral lipoma: a meta-analysis. Neurosurg Rev. 2016 Oct 28. [Epub ahead of print] Review. PubMed PMID: 27796602.

Nejat A, Habibi Z, Nejat F. Lumbosacral Lipomyelomeningocele with Lateral Attachment to Neural Placode: Case Illustration. Pediatr Neurosurg. 2021 Mar 29:1-3. doi: 10.1159/000513409. Epub ahead of print. PMID: 33780945.

Sarmento-Gonçalves I, Cunha M, Loureiro T, Pinto PS, Ramalho C. Fetal lipomyelomeningocele: A closed neural tube defect diagnosed at second trimester ultrasound examination. J Clin Ultrasound. 2018 Nov 8. doi: 10.1002/jcu.22662. [Epub ahead of print] PubMed PMID: 30411358.

Wilkes SL, Choi JJ, Rooks VJ. Lumbosacral lipomyelomeningocele with anomalous osseous limb in a 3-month-old female. Radiol Case Rep. 2015 Dec 3;10(1):1051. doi: 10.2484/rcr.v10i1.1051. PMID: 27408662; PMCID: PMC4921161.

Lumbosacral dural arteriovenous fistula

Lumbosacral dural arteriovenous fistula


The most common neurologic findings at the time of admission were paraparesis (85%), sphincter dysfunction (70%), and sensory disturbances (20%).

Clinical symptoms caused by deep lumbosacral spinal dural arteriovenous fistulas are comparable with those of spinal dural arteriovenous fistulas at other locations 1).


Spinal dural arteriovenous fistulas located in the deep lumbosacral region are rare and the most difficult to diagnose among spinal dural arteriovenous fistulas located elsewhere in the spinal dura. Specific clinical and radiologic features of these fistulas are still inadequately reported.

Medullary congestion in association with an enlargement of the filum vein or other lumbar radicular veins is a characteristic finding in these patients. Spinal time-resolved contrast-enhanced dynamic MRA facilitates the detection of the drainage vein and helps to localize deep lumbosacral-located fistulas with a high sensitivity before DSA. Definite detection of these fistulas remains challenging and requires sufficient visualization of the fistula-supplying arteries and draining veins by conventional spinal angiography.

Medullary T2 hyperintensity and contrast enhancement were present in most cases. The filum vein and/or lumbar veins were dilated in 19/20 (95%) patients. Time-resolved contrast-enhanced dynamic MRA indicated a spinal dural arteriovenous fistula at or below the L5 vertebral level in 7/8 (88%) patients who received time-resolved contrast-enhanced dynamic MRA before DSA. A bilateral arterial supply of the fistula was detected via DSA in 5 (25%) patients 2).


Patients with deep lumbosacral dural arteriovenous fistula had a higher risk of early recurrence compared to patients with thoracolumbar SDAVF, with a considerable percentage of late functional deterioration. Thus strict clinical and radiologic long-term follow-up examinations are recommended in those patients 3).

Case series

Jablawi et al. retrospectively evaluated all data of patients with spinal dural arteriovenous fistulas treated and/or diagnosed in RWTH Aachen University Hospital, and Paracelsus Kliniken, OsnabrückGermany, between 1990 and 2017. Twenty patients with deep lumbosacral spinal dural arteriovenous fistulas were included in this study.

They retrospectively analyzed our radiological and medical records for patients presenting with SDAVF between 1990 and 2018 at the University Hospital Aachen. We identified twenty patients with a lsDAVF. All patients were treated surgically. One patient died of pulmonary embolism three months after treatment and was excluded from our outcome analysis. Clinical data at the time of admission, discharge, one year after discharge and at the last follow-up were evaluated according to the modified Aminoff-Logue disability score (AL-score) for this analysis.

The mean age was 65 ± 7 years (median, 67; range, 53-78), sixteen patients (84 %) were male. After surgery, four patients developed a recurrent fistula in the same shunt zone and were re-treated microsurgically. Follow-up data one year after treatment was available in 15 patients. No relevant changes in AL-score were observed within this period. For the long-term follow-up analysis, data of 13 patients were available; 38.5 % of patients developed late functional deterioration.

In this cohort, patients with deep lumbosacral dural arteriovenous fistula had a higher risk of early recurrence compared to patients with thoracolumbar SDAVF, with a considerable percentage of late functional deterioration. Thus strict clinical and radiologic long-term follow-up examinations are recommended in those patients 4).

Rosi et al. describe a case series of five patients presenting with a conus medullaris AVS associated with a lower lumbar or sacral DAVF.

Three of the patients were <30 years old at presentation. In four of these five cases the intradural scAVS drained caudally, engorging the epidural plexus in the same location as the sDAVF. In only one case, who presented with thrombosis of the drainage of the main compartment of a conus medullaris pial AVF, was the location of the DAVF opposite to the location of the residual drainage.

They discuss the pathophysiological link between scAVS and sDAVF on the basis of the rarity of the DAVF, the uncommon association between scAVS and sDAVF, the presence of sDAVF in young patients, and the venous hypertension created by the venous drainage towards the sacral area responsible for angiogenesis creating the dural shunt 5).

Twenty-five consecutive patients with 16 thoracic dural arteriovenous fistula and 9 lumbosacral DAVFs were included (mean age, 63.9 years; 20 men). All patients presented with progressive myelopathy. Preoperative and postoperative neurologic deficits were compared between thoracic and lumbosacral DAVF groups. Using magnetic resonance imaging, the extent of T2 high-intensity areas and signal flow voids were documented. Follow-up after surgical interventions ranged from 6 to 96 months (mean, 38.1 months).

Preoperatively, patients suffering lumbosacral DAVF tended to be more severely disabled compared with thoracic DAVF patients. Lumbosacral DAVF patients exhibited diminished patellar (P = 0.04) and Achilles tendon reflexes (P < 0.01), while most thoracic DAVF patients exhibited hyperreflexia. In magnetic resonance imaging, signal flow voids around the spinal cord were evident in only 4 of 9 lumbosacral DAVF patients (P = 0.012). Rather, a serpentine signal flow void of the filum terminale was a hallmark of lumbosacral DAVFs to distinguish them from thoracic DAVFs. In the lumbosacral DAVF group, postoperative improvements were significantly better in micturition function (P = 0.02).

In lumbosacral DAVF, postoperative micturition function recovery was superior to thoracic DAVF. Intradural lumbar signal flow void is indicative of lumbosacral DAVF. For appropriate management, it is important to recognize these differences between lumbosacral and thoracic DAVF 6).

Case reports

A 65-year-old man presented with a 4-year history of progressive sensory, motor, and sphincter dysfunction. Spinal magnetic resonance imaging and digital subtraction angiography showed 2 spinal dural arteriovenous fistulas (fed by the right L2 lumbar artery and the right lateral sacral artery, respectively) and 1 perimedullary arteriovenous fistula (fed by the filum terminale artery from the left L2 lumbar artery [i.e., filum terminale arteriovenous fistulas]. A hybrid technique was used to perform embolization of the right L2 spinal dural arteriovenous fistula and microsurgery of the L5 level filum terminale vein. The patient was asymptomatic 1 year later.

Multifocal spinal vascular malformations may coexist in 1 case, and standardized spinal digital subtraction angiography, including the bilateral internal iliac arteries and median sacral artery, should be performed to avoid a missed diagnosis. The concomitant phenomenon indicates that venous hypertension may be a risk factor for the development of arteriovenous fistulas. Hybrid techniques are effective in treatment of multifocal and complex spinal AVMs 7).

Seven cases of adult spinal vascular malformations presenting in conjunction with spinal dysraphism have been reported in the literature. Two of these involved male patients with a combined dural arteriovenous fistula (DAVF) and lipomyelomeningocele. The authors present the third case of a patient with an extraspinal DAVF and associated lipomyelomeningocele in a lumbosacral location. A 58-year-old woman with rapid decline in bilateral motor function 10 years after a prior L4-5 laminectomy and cord detethering for diagnosed tethered cord underwent magnetic resonance imaging showing evidence of persistent cord tethering and a lipomyelomeningocele. Diagnostic spinal angiogram showed a DAVF with arterial feeders from bilateral sacral and the right internal iliac arteries. The patient underwent Onyx embolization of both feeding right and left lateral sacral arteries. At 6-month follow-up, MRI revealed decreased flow voids and new collateralized supply to the DAVF. The patient underwent successful lipomyelomeningocele exploration, resection, AV fistula ligation, and cord detethering. This report discusses management of this patient as well as the importance of endovascular embolization followed by microsurgery for the treatment of cases with combined vascular and dysraphic anomalies 8).


1) , 2) , 3) , 4)

Jablawi F, Nikoubashman O, Dafotakis M, Schubert GA, Hans FJ, Mull M. Treatment strategy and long-term outcome in patients with deep lumbosacral arteriovenous fistulas. A single center analysis in nineteen patients. Clin Neurol Neurosurg. 2019 Nov 11;188:105596. doi: 10.1016/j.clineuro.2019.105596. [Epub ahead of print] PubMed PMID: 31739154.

Rosi A, Consoli A, Condette-Auliac S, Coskun O, Di Maria F, Rodesch G. Concomitant conus medullaris arteriovenous shunts and sacral dural arteriovenous fistulas: pathophysiological links related to the venous drainage of the lesions in a series of five cases. J Neurointerv Surg. 2018 Jun;10(6):586-592. doi: 10.1136/neurintsurg-2017-013505. Epub 2018 Jan 19. PubMed PMID: 29352055.

Endo T, Kajitani T, Inoue T, Sato K, Niizuma K, Endo H, Matsumoto Y, Tominaga T. Clinical Characteristics of Lumbosacral Spinal Dural Arteriovenous Fistula (DAVF)-Comparison with Thoracic DAVF. World Neurosurg. 2018 Feb;110:e383-e388. doi: 10.1016/j.wneu.2017.11.002. Epub 2017 Nov 10. PubMed PMID: 29133002.

Li J, Li G, Bian L, Hong T, Yu J, Zhang H, Ling F. Concomitant Lumbosacral Perimedullary Arteriovenous Fistula and Spinal Dural Arteriovenous Fistula. World Neurosurg. 2017 Sep;105:1041.e7-1041.e14. doi: 10.1016/j.wneu.2017.06.149. Epub 2017 Jul 4. PubMed PMID: 28684369.

Krisht KM, Karsy M, Ray WZ, Dailey AT. Extraspinal type I dural arteriovenous fistula with a lumbosacral lipomyelomeningocele: a case report and review of the literature. Case Rep Neurol Med. 2015;2015:526321. doi: 10.1155/2015/526321. Epub 2015 Apr 8. PubMed PMID: 25949837; PubMed Central PMCID: PMC4407406.
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