CASE REPORT

Giant intrasacral meningocele: a case report

Melih Bozkurt & Gokmen Kahilogullari & Umit Eroglu & Atilla Erdem

Received: 8 March 2013 /Accepted: 30 April 2013 /Published online: 19 May 2013# Springer-Verlag Berlin Heidelberg 2013

Abstract A peculiar case of intrasacral meningocele andspinal cord tethering is reported. Contents of the intrasacralmeningocele and importance of CSF flow analyses withMRI are discussed. Demonstration of CSF flow from thethecal sac to meningocele in the CSF flow MR imaging maybe helpful for determining the possibility of meningocelegrowth. In this report, we have presented the determinationof CSF flow as a new surgical indication in this type ofcases.

Keywords Intrasacral meningocele . Tethered cord .

CSF flow .MRI

Introduction

Intrasacral meningocele is an atypical enlargement of thethecal sac on the far side of its normal termination. Thecommunication between the intrasacral meningocele and theneighboring thecal sac is typically constituted by a one-sided ostium. CSF flows from the tip of the subarachnoidspace into the meningocele through this ostium. The theo-ries of abnormal embryogenesis suggested as explanationsfor the development of this anomaly. The sacrococcygealneural elements develop after closure of the posteriorneuropore. The caudal cells enlarge and undergo canaliza-tion. This occurs from the fourth to the sixth week of life.Cellular degeneration along the distal neural tube producesthe filum terminale. Lying at the distal end of the filumterminale, the coccygeal medullary vestige may be the ori-gin of the intrasacral meningocele [1, 2].

These lesions do not typically consist of neural elements[3]. The sac is composed of a fibrous tissue having thehallmarks of dura and lined by arachnoid. Sacral spinalcanal is often widened and abraded. A dysraphic etiologyis substantiated by an interconnection with spina bifida andtethered cord syndrome [4].

We present a case of an occult intrasacral meningocelepresenting with severe constipation and low back pain andalso review of the literature. We also emphasize the impor-tance of cine mode MR imaging and CSF flow analysiscontributed to the certainty of communication between theintrasacral meningocele and neighboring thecal sac.

Case

This 16-year-old girl presented with a 6-year history ofconstipation and low back pain. During this time period,the patient was followed by rheumatology clinics and med-ical therapy with non-steroidal anti-inflammatory drugs wasadministered and additionally she got physical therapy. Shealso suffered numbness in the left leg and difficultly inwalking. Physical examination revealed no abnormality.

Preoperative MRI revealed spinal cord tethering and lowlying conus medullaris accompanying with a large, centrallylocated intrasacral meningocele between S2 and S4 seg-ments (Fig. 1). Tethered filum terminale was visible at thedistal part of the thecal sac and the superior part of themeningocele. Sacral nerve roots were compressed ventrally;CSF flow analysis with MRI revealed flow from the thecalsac to the meningocele through a defect at the bottom of thethecal sac (Fig. 2).

Laminectomies were performed from S1 to S3 and themeningocele was exposed. The meningocele was observedas a pulsatile cyst in the spinal canal. The meningocele wasentered from the caudal point with the help of an operatingmicroscope and high-pressure CSF discharged from the

M. Bozkurt :G. Kahilogullari (*) :U. Eroglu :A. ErdemDepartment of Neurosurgery, School of Medicine,Ankara University, Ankara 06100, Turkeye-mail: gokmenkahil@hotmail.com

Childs Nerv Syst (2013) 29:21232125DOI 10.1007/s00381-013-2141-5

meningocele cavity. The ostium of the meningocele wasobserved at the superior part of the meningocele and thefilum terminale was observed through the ostium (Fig. 3).Filum terminale was coagulated and untethered. Ostium wasclosed with 5.0 silk and the dorsal part of the meningocelewall was removed. Because of the tight adherence of ventralwall to the sacral rootlets, ventral wall was not removed.

Immediately after the procedure, numbness of the left legand low back pain reduced. Three months after the surgery,constipation, walking difficulty, and low back pain werecompletely resolved. The follow-up is 2 years without anysymptoms.

Discussion

After the first description of intrasacral meningocele byEnderle in 1932, several studies reported this unique pathol-ogy [5]. The contents of the meningocele were discussed inthe literature and concluded that meningocele cavity is

devoid of any other structure except CSF [3]. Three studiesdemonstrated tethered filum terminale settling in themeningocele cavity [4, 6, 7]. Feigenbaum discussed thattethering of the filum and the meningocele formation mayoccur independently but simultaneously. In the presentedcase, the filum terminale was attached to the inner part ofthe cyst cavity.

Fig. 1 Preoperative sagittal plane-MRI revealed spinal cord tetheringand low lying conus medullaris accompanying with a large, centrallylocated intrasacral meningocele between S2 and S4 segments

Fig. 2 CSF flow analysis with MRI revealed flow from the thecal sac tothe meningocele through a defect at the bottom of the thecal sac (arrow)

Fig. 3 The ostium of the meningocele and the filum terminale wereobserved at the superior part of the meningocele (arrow)

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For the most part of the patients, intrasacral meningoceleis asymptomatic. When they compress the sacral rootlets,they become symptomatic and generally give rise to clinicalcomplaints. If the tethered cord accompanies intrasacralmeningocele, further complaints related with tethered cordmay occur. Additionally, as a result of sacral spine erosion,patients are afflicted by lower back or buttock pain. In ourcase, in view of the surgical observation, the lesion waspulsatile and increased in size as a result of one-sided valvemechanism. The compression of the sacral rootlets ventrallyand sacral bone erosion should be explained with this sur-gical observation.

MRI of the sacral region is the investigation of choice forthe diagnosis [8]. If there is a question that arises concerningabout the communication between the thecal sac andmeningocele, cine MRI and CSF flow analyzing should beconsidered as a diagnostic device to demonstrate the signalvoid because of the unidirectional flow and estimate theprobability of enlarging the cyst size. This observation shouldorientate to the surgery even in asymptomatic patients.

Treatment strategies for the intrasacral meningocele arestill controversial. In asymptomatic cases, follow-up issuggested, while in symptomatic cases, surgery isrecommended. Since the intrasacral meningocele may ex-pand in size and there is a probability of becoming symp-tomatic, there is a difficulty in terms of estimating thechance of this complication. CSF flow analysis may behelpful in predicting the cyst enlargement and planning thesurgical intervention as a therapeutic modality. Surgicaltreatment of the intrasacral meningocele is excision of thecyst via posterior approach. Since the surgical treatment isconsidered in symptomatic cases because of the enlargementof the cyst and compression of the sacrococcygeal nerveroots, dissection of the ventral surface of the cyst fall fromthe sacrococcygeal nerve roots can cause catastrophic com-plications. The ostium between the cyst and the thecal sacshould be sutured and fascia graft can be attached to theostium and fibrin glue can be used to prevent the regrowth

of the lesion. We observed numerous types of cases similarto our cases in the literature; nevertheless, we believe thatreceiving inadequate treatment for this type of well-documented lesion for 6 years should be worthy of contri-bution to the neurosurgical literature [1, 5, 6].

Conclusion

As a consequence of surgical findings, cine mode MRimaging and CSF flow analysis contributed to the certaintyof communication between the intrasacral meningocele andneighboring thecal sac can be considered as a reference forevaluate the likelihood growing of the meningocele.

References

1. Doty JR, Thomson J, Simonds G, Rengachary SS, Gunby EN(1989) Occult intrasacral meningocele: clinical and radiographicdiagnosis. Neurosurgery 24(4):616625

2. Lamas E, Lobato RD, Amor T (1977) Occult intrasacralmeningocele. Surg Neurol 8(3):181184

3. Feigenbaum F (2008) Giant sacral meningeal diverticulumcontaining a thickened filum with lipoma in an adult with spinalcord tethering. Case report and review of the literature. J NeurosurgSpine 9(3):281284

4. Feigenbaum F, Hale S (2011) Association between symptomaticgiant sacral meningeal diverticulum and spinal cord tethering withthickened lipomatous filum. Spine 36(18):E12301232

5. Turgut M, Akyuz O, Unsal A (2007) Occult intrasacralmeningocele: case report and review of the literature. ZentralblNeurochir 68(1):3437

6. Doi H, Toyoda I, Matsumoto K, Imai S, Sekimizu M (1995) Occultintrasacral meningocele with tethered cordcase report. NeurolMed Chir (Tokyo) 35(5):321324

7. Parmar H, Shah J, Varma R, Patkar D (2001) Intrasacralmeningocele with tethered cord syndrome. J Assoc of PhysiciansIndia 49:746748

8. Rengachary SS, OBoynick P, Karlin CA, Batnitzky S, Price H(1981) Intrasacral extradural communicating arachnoid cyst: casesreport. Neurosurgery 8(2):236240

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Giant intrasacral meningocele: a case reportAbstractIntroductionCaseDiscussionConclusionReferences