J Neurosurg Pediatrics 11:615–622, 2013 ©AANS, 2013 Intrasacral meningocele in the pediatric population Clinical article SUBASH LOHANI, M.D.,1 DIANA P. ROdrIGUEZ, M.D.,2 HART G. W. LIDOV, M.D.,3 R. MICHAEL SCOTT, M.D.,1 AND MARK R. PROCTOR, M.D.1 Departments of 1Neurosurgery, 2Neuroradiology, and 3Neuropathology, Boston Children’s Hospital, Boston, Massachusetts Object. Intrasacral meningoceles are rare cystic lesions that can cause focal compression within the bony sacral canal. Their mechanisms are poorly understood, but most intrasacral meningoceles appear to be intrasacral extradural cysts caused by arachnoid herniating through a small dural defect in the caudal end of the thecal sac. As opposed to perineural cysts, they are not associated with an exiting nerve root. When symptomatic, they can cause sacral pain or sacral nerve root dysfunction due to local compression. Methods. This is a retrospective series from Boston Children’s Hospital. All patients in whom symptomatic intrasacral meningocele that required surgical treatment was diagnosed between May 1994 and March 2011 were included in the study. Spine MRI was the diagnostic modality of choice. All patients underwent sacral exploration, with ligation and obliteration of the cyst. Resected cyst wall was subjected to pathological examination. Results. There were 13 patients (11 boys and 2 girls) who underwent operation for intrasacral meningocele. The median age was 8 years (range 5 months–16 years). The most common presenting symptom was back pain (in 5) often described as deep tail bone pain, followed by urinary incontinence (3) and constipation (2). Three patients had evidence of associated tethered cord on MRI studies. Four patients were asymptomatic and their diagnosis was made following imaging for other reasons; they were surgically treated because of the increasing size of the lesion or association with other congenital lesions. Most patients had symptomatic improvement after surgery. Conclusions. Intrasacral meningoceles are rare lesions that may result from a congenital dural weakness and a resultant arachnoid diverticulum. They present in childhood either incidentally or with symptoms secondary to nerve root compression. Identification of the point of herniation through the dura mater and ligation of the lesion provides cyst cure and resolution of symptoms in most patients. (http://thejns.org/doi/abs/10.3171/2013.3.PEDS12519) KEY WORDS • intrasacral meningocele • sacral canal • congenital cyst HIS study was undertaken to categorize the clini- root, were not included, although some lesions had as- cal presentation, radiological appearance, surgical sociated tethering pathology. anatomy, and operative results in pediatric patients Tundergoing operation for intrasacral meningocele. This series focuses only on the occult intrasacral meningo- Methods celes, defined as extradural cysts associated with herniat- This is a retrospective study conducted at Boston ing arachnoid, but not associated with an exiting nerve Children’s Hospital. After obtaining institutional review root. Due to their relative rarity, the literature on intrasa- board approval, charts were reviewed to identify all pa- cral meningoceles has been limited to case reports, and tients who were surgically treated for intrasacral menin- we believe that our report represents the first published gocele between May 1994 and March 2011, and to deter- operative series of intrasacral meningoceles. Perineural mine presenting signs and symptoms, imaging findings, cysts, defined as cysts associated with an exiting nerve anatomy at surgery, and postoperative results based on This article contains some figures that are displayed in color Abbreviations used in this paper: GFAP = glial fibrillary acidic on line but in black-and-white in the print edition. protein; UDS = urodynamic studies. J Neurosurg: Pediatrics / Volume 11 / June 2013 615 Unauthenticated | Downloaded 10/04/21 12:09 PM UTC S. Lohani et al. imaging and clinical follow-up examinations. All surger- ted for pathological examination. This included paraffin ies were performed at our institution, predominantly by sections stained with H & E, Masson Gomori trichrome, the senior author (M.R.P.). and immunostained for GFAP and epithelial membrane antigen. The sections were retrospectively reviewed by Patient Evaluation one of the authors (H.G.W.L.). All patients underwent full clinical examination, and adjuvant tests such as UDS were performed based Results on symptoms and clinical findings. Radiographic studies included MRI of the spine for the accurate delineation There were total of 13 patients in whom operations of the lesion in all patients. There was a single instance were performed for intrasacral meningocele between each in which spine ultrasound and CT myelography was May 1994 and March 2011. There were 11 boys and 2 also performed. The UDS were done if the patient had girls (5.5:1 male/female ratio). The age range at surgery urological symptoms. was 5 months to 16 years. The median age was 8 years. Surgical Procedure Presenting Symptoms All operations were performed with the patients under The most common presenting symptom was nonra- general anesthesia. Neuromonitoring was used to monitor diating back pain (5 patients), typically described by the sacral nerve root and leg function. Identification of the spi- child as a deep tail bone pain. Three patients had uri- nal level and surgical opening were performed using pal- nary incontinence and their UDS demonstrated overac- pable anatomical landmarks, and rarely radiography. The tive bladder, intermittent flow patterns, and high postvoid operating microscope was used in all cases. The goal of residuals, all consistent with neurogenic bladder. Two surgery was to identify and ligate the connection between patients had constipation. Lower-extremity weakness the thecal sac and the extradural cyst. Nerve roots adherent and recurrent urinary tract infection were seen in 1 pa- to the exterior walls of the cyst were dissected off and a tient each. Four patients were asymptomatic and diag- silk suture was passed around the takeoff of the cyst at the nosed as a part of imaging for other reasons, including base of the thecal sac. The cyst was then opened and ex- sacral dimple, asymmetrical gluteal cleft, and presence plored internally to confirm that it did not contain any neu- of other congenital anomalies like multiple segmentation ral elements. The circumference of the cyst was electrically and fusion vertebral anomalies. Additional findings that stimulated to be certain there were no active motor roots, we observed on clinical examination were sacral dimple and after the lesion was definitively isolated, the silk stitch in 3 patients (2 with benign sacral dimple and 1 associ- was secured at the base of the cyst to eliminate its connec- ated with asymmetrical gluteal cleft) and a dermal sinus tion with the dura mater. A Valsalva maneuver was then tract in 1 child. One patient in our series developed an performed by the anesthesiologist to test the competency intrasacral meningocele after a traumatic epidural spinal of the ligation. In some cases the cyst walls were removed anesthetic and presented with subtle lower-extremity mo- and sent for pathological examination. The newly created tor weakness and depressed ankle jerk, which partially dead space was filled with either fat from the soft tissues or improved after surgery. The clinical findings in these pa- with collagen sponge (Fig. 1). tients are summarized in Table 1. Pathological Examination Surgical Findings In 4 patients the cyst wall was resected and submit- In all patients a well-circumscribed cyst with smooth FIG. 1. A: Intraoperative photograph showing a cyst (left side of panel) at the distal end of the thecal sac; a silk ligature is passed around its connection with the dura mater. B: The silk tie is secured and the cyst is opened and explored. C: The cyst wall is resected after confirming that it is free of nerve roots. 616 J Neurosurg: Pediatrics / Volume 11 / June 2013 Unauthenticated | Downloaded 10/04/21 12:09 PM UTC J Neurosurg: Pediatrics / Volume 11 /June 2013 / Volume11 J Neurosurg:Pediatrics Intrasacral meningocele in the pediatric population in thepediatric meningocele Intrasacral TABLE 1: Characteristics, clinical presentation, and surgical outcome in 13 patients with intrasacral meningocele* Case No. Age, Sex Imaging Findings Symptoms & Signs Associated Findings Outcome 1 7 yrs, F S1–3 cyst, 2.3 cm urinary incontinence, recurrent UTI, constipation fatty filum, TSC partial resolution (constipation did not improve) 2 5 mos, M S2–3 cyst, 0.8 cm asymptomatic, sacral dimple fatty filum, TSC, spina bifida w/ low-lying conus prophylactic ligation & obliteration of cyst 3 11 yrs, M L5–S1 pseudo-cyst, limping gait, weakness, hyporeflexia, loss of foot none partial resolution (slight limping still present) 3.4 cm curvature 4 5 yrs, M S2–3 cyst, 1.8 cm severe back pain none complete resolution 5 16 yrs, F S1–2 cyst, 3 cm deep back pain dermal sinus tract complete resolution 6 15 yrs, M L5–S4 cyst, 8 cm back & leg pain, urinary incontinence none partial resolution (incontinence not improved) 7 2.5 yrs, M L5–S3 cyst, 5 cm asymptomatic, sacral dimple spina bifida prophylactic ligation & obliteration of cyst 8 9 mos, M L5–S3 cyst, 4.2 cm asymptomatic, sacral dimple, asymmetrical glu- TSC prophylactic ligation & obliteration of cyst teal cleft 9 16 yrs, M S1–4 cyst, 6.9 cm episodic back pain none complete resolution 10 9 yrs, M L5–S5 cyst, 8.2 cm urinary incontinence none complete resolution 11 8 yrs, M S2–4 cyst, 2 cm constipation, fecal incontinence S-2 defect/open complete resolution 12 1.5 yrs, M S1–3 cyst, 1.2 cm incidental TSC, low-lying conus, multiple segmentation & prophylactic ligation & obliteration of cyst fusion, vertebral anomalies w/ holocord syrinx 13 11 yrs, M S1–2 cyst, 3 cm back pain & spasms none complete resolution Unauthenticated |Downloaded 10/04/21 12:09 PMUTC * TSC = tethered spinal cord; UTI = urinary tract infection. 617 S.