Ventral anchoring of the conus medullaris: a new surgical technique preventing the radiographic recurrence of retethering after surgery for tethered spinal cord

OBJECTIVE

Retethering is not an unusual operation for a congenital lumbosacral dysraphic spinal lesion. The present study aimed to assess a new surgical technique for preventing retethering.

SURGICAL TECHNIQUE

After untethering the spinal cord, the pia mater or scar tissue at the caudal end of the conus medullaris is anchored to the ventral dura mater loosely using 8-0 thread, and the dura mater is closed directly. This technique is called ventral anchoring.

RESULTS

Ventral anchoring was performed in 15 patients (aged 5 to 37 years old, average age: 12.1 years old) between 2014 and 2021. All but one patient showed improvement or stabilization of the preoperative symptoms. No complication directly related to the procedure was observed. Postoperative MRI demonstrated that the dorsal subarachnoid space was restored in 14 patients but was undetectable or absent in three patients on follow-up MRI. No patients have experienced a recurrence of the tethered cord syndrome during the follow-up period.

CONCLUSION

Ventral anchoring is effective for restoring the dorsal subarachnoid space after untethering the spinal cord. This preliminary study suggested that ventral anchoring has the potential to prevent the postoperative radiographic recurrence of tethered spinal cord in patients with a congenital lumbosacral dysraphic spinal lesion.

Electrodiagnostic findings of retethering in children with spinal dysraphism

PURPOSE

Retethering of the cord can occur after the initial untethering surgery. Typical neurological manifestations indicative of cord tethering are often difficult to determine in pediatric patients. Patients who had a primary untethering operation are likely to present with some degree of neurological deficits from a previous tethering event, and urodynamic studies (UDSs) and spine images are frequently abnormal. Therefore, more objective tools to detect retethering are needed. This study sought to delineate the characteristics of EDS of retethering, and therefore, could support the diagnosis of retethering.

METHODS

Among 692 subjects who had an untethering operation, data from 93 subjects who had been suspected of retethering clinically were retrospectively extracted. The subjects were divided into two groups, a retethered group, and a non-progression group, according to whether or not surgical interventions had been performed. Two consecutive EDSs, clinical findings, spine magnetic resonance imaging scans, and UDSs before the development of new tethering symptoms were reviewed and compared.

RESULTS

In the electromyography (EMG) study, the appearance of abnormal spontaneous activity (ASA) in new muscles was prominent in the retethered group (p < 0.01). The loss of ASA was more pronounced in the non-progression group (p < 0.01). Specificity and sensitivity of EMG for retethering were 80.4 and 56.5%, respectively. In the nerve conduction study, the two groups did not show differences. The size of fibrillation potential was not different between the groups.

CONCLUSIONS

To provide support for a clinician's decision on retethering, EDS could be an advantageous tool with high specificity when the results are compared to previous EDS results. Routine follow-up EDS post-operatively is recommended as a baseline for comparison at the time when retethering is clinically suspected.

Importance of urodynamic evaluation of bladder function after secondary untethering in spina bifida patients: single center experience of 30 years

INTRODUCTION

A TCS after primary closure of meningomyeloceles is a known complication of the spina bifida disease. Data on the outcome after SSCU surgery is heterogeneous and lacking standardization. Thus we aimed to find a reliable system for assessment of the bladder function before and after SSCU surgery and document postoperative outcome.

METHODS

A retrospective study was performed on a cohort of patients with spina bifida diagnosis. In total, 130 patients underwent 182 SSCU surgeries, 56 of those met our inclusion criteria. A classification system, including two different methods, was used. The AC system used baseline pressure and detrusor over activity to define three levels of bladder dysfunction, the second method ranked the severity of bladder dysfunction by awarding points from 0 to 2 for bladder capacity, maximal detrusor pressure during autonomous contractions, leak point pressure and vesicoureteral reflux A high score is correlated with a severe bladder dysfunction.

RESULTS

Gender distribution was equally (male: n = 29; 51.8%; female: n = 27; 48.2%). The median age at SSCU was 902 years (range 0.5-22.8 years). After SSCU, the stage improved in 11 patients (19.6%), worsened in 11 (19.6%) patients and remained the same in 34 patients (60.7%) after intervention (AC score). Non-worsening was observed in a total of 45 cases (80.4%) (p < 0.001). MHS score (n = 27, 48.2%) improved, remained unchanged (n = 12, 21.4%), 17 patients worsened (30.4%). Non-worsening in postoperative bladder functional outcome was demonstrated in 39 cases (69.6%) over all (p < 0.005). Regardless of whether bladder function is categorized by AC or MHS, postoperative outcome worsened significantly when SSCU was performed due to increasing deterioration in motor function alone (p < 0.05). Of the 24 cases with NOD as indication, 22 (91.7%) had an unchanged (n = 10; 41.7%) or improved (n = 12; 50.0%), meaning positive neuro-orthopedic outcome, only 2 (8.3%) deteriorated (p < 0.001).

CONCLUSION

Our study presents reliable evaluation systems for bladder function in spina bifida patients. Since indications for SSCU surgery differ, it is important to know the possible effects on bladder function after this surgical procedure. Even a mild impairment of bladder function has a risk to deteriorate after SSCU surgery. Particularly interesting becomes this with regard to the fact that the prevalence of TCS might become more frequent with the rising numbers of prenatal closures of meningomyeloceles.

Minimal invasive interlaminar approach for untethering of fatty filum terminale in pediatric patients - how I do it

BACKGROUND

Fatty filum terminale is a form of spinal dysraphism and a third of all patients develop symptoms such as sensory, motor, and urinary impairment. Early surgery at 6 months has the advantage that the bone density is still soft, and the patients are not ambulatory yet, promoting faster healing.

METHOD

We present our minimal invasive surgical technique for FFT untethering.

CONCLUSION

Due to the low complication rate and the potentially high benefit of surgery, prophylactic untethering is recommended.

Occult tethered cord syndrome: a rare, treatable condition

PURPOSE

Occult tethered cord syndrome (OTCS) is an entity that shows tethered cord syndrome (TCS) with normal spinal MRI findings. The definition and treatment of OTCS have been controversial since first proposal. The purpose of this study was to evaluate the existence, prevalence, histological characteristics, and surgical outcomes of OTCS.

METHODS

We retrospectively analyzed patients who underwent untethering surgery for OTCS from January 2010 to December 2019. Inclusion criteria were (1) clinical manifestation of TCS; (2) supported by urodynamic study (UDS) or electromyography/nerve conduction study; (3) no structural lesions in the urological tract or spinal cord, and no developmental delay; and (4) postoperative follow-up for > 6 months. Sectioned fila from OTCS patients were histologically compared with those from cases of thickened filum or low-lying conus.

RESULTS

Five (four female, one male) of 439 patients (1.1%) who underwent untethering surgeries for occult spinal dysraphism corresponded to OTCS. Mean age at the time of surgery was 16 years (7-22 years). Mean postoperative follow-up duration was 45 months (15-114 months). The main symptom was urinary dysfunction in four patients and leg pain in one. All patients had detrusor-sphincter dyssynergia. Fila from OTCS patients revealed increased fibrous tissue as in TCS patients. Four patients showed postoperative improvement and one with preoperative static course had no improvement.

CONCLUSIONS

This study suggests that OTCS is a definitely existing entity although rare. OTCS is curable when timely treatment is given. Sudden onset with rapid progression of symptom seems the best indication for surgery.

Spinal cord deformity with aggravation of tethering in saccular limited dorsal myeloschisis during the first 2 months of life

Background

Although the optimal timing of prophylactic untethering surgery for limited dorsal myeloschisis (LDM) with intact or subtle neurological findings diagnosed at birth remains undetermined, intentional delayed surgery is commonly used for flat and tail-like LDM. Conversely, for saccular LDM, early surgery is indicated during the postnatal period because it prevents rupture of the sac. We treated a saccular LDM patient, in whom intentional delayed surgery was selected because the sac was thickly covered with normal skin. We describe the clinical course of the case and discuss the optimal timing of the surgery.

Case Description

The patient had a dorsal midline sac in the upper lumbar region. Initial magnetic resonance imaging (MRI) after birth revealed a tethering tract that began at the dome of the sac and joined the lumbar cord. Dorsal bending of the cord at the stalk-cord union and invagination of the cord into the sac were noted. At 2 months, he was neurologically normal; however, the second MRI examination revealed that the cord tethering was aggravated. The cord was markedly displaced dorsally and to the left, with deviation of the cord to the sac out of the spinal canal. Following untethering surgery, the spinal cord deformity markedly improved.

Conclusion

Early surgery may be recommended for saccular LDM when tethering is present, including dorsal bending of the cord at the stalk-cord union and invagination of the cord into the sac observed on detailed MRI examination, even if the sac has no risk of rupture.

Posterior Surgical Approach for Ventral Cervical Spinal Cord Herniation: 2-Dimensional Operative Video

Spinal cord herniation (SCH) is a rare condition that is typically of idiopathic origin. Although SCH is mostly found in the thoracic region because of a dural defect, there are some reports of cervical SCH following surgery or trauma.1-3 Spinal cord tethering can be a result of SCH or as a standalone issue.4,5 These conditions can lead to progressive neurological deficits, including numbness, gait disturbances, and decreased muscle strength, requiring surgical correction. There are limited reports of surgical procedures for ventral SCHs. Several reports exist using a ventral approach for intradural tumors, but it is not commonly employed because of the inability to obtain adequate dural closure.6 Much of the literature on SCH comes from idiopathic and congenital cases in the thoracic spine.7,8 Posterior and posterolateral approaches for a ventral thoracic SCH have been described, as well as an anterior approach for a ventral cervical SCH.9-12 In this video, we describe a posterior approach for a ventral cervical SCH. A 38-yr-old male presented with progressive cervical myelopathy 9 yr after a C2-C3 schwannoma resection requiring an anterior approach and corpectomy of C3 with partial corpectomies of C2 and C4. A preoperative magnetic resonance imaging showed a ventrally herniated spinal cord at the top of the C3 vertebral body and below the C4 vertebral body. Informed consent was obtained. The posterior surgical approach involved a C1-C5 laminectomy, sectioning the dentate ligament, ventral cord untethering, removal of residual tumor, and placement of a ventral sling. A significant improvement in sensory and motor function was observed postoperatively.

Surgical outcomes by sectioning a filum terminale in patients with terminal syringomyelia

BACKGROUND

Although terminal syringomyelia suggests a tethered spinal cord, a consensus has still not been established for surgical indications, when there are no associated abnormalities or only minor associated abnormalities. We analyzed surgical outcomes of sectioning a filum terminale in patients with terminal syringomyelia to elucidate the significance of untethering surgery.

METHODS

Fifty-seven pediatric patients with terminal syringomyelia who underwent untethering via sectioning the filum terminale between 2007 and 2018 were retrospectively analyzed. Postoperative outcomes of symptoms and MRI findings were evaluated.

RESULTS

Of 57 patients, 40 had other associated abnormalities (25 with filar lipoma and 29 with low conus medullaris) that could be responsible for tethered cord. Nineteen patients had symptoms. The mean age at the time of surgery was 18 months (3-96 months). The mean follow-up period was 3.3 years (1-9 years). Preoperative symptoms improved in 9 patients (47%) after surgery. At 1 year after the surgery, the size of syringomyelia decreased in 19 (33%), increased in 4 (8%), and did not change in 34 (69%) patients. Of 28 patients who were followed up for more than 3 years, the size decreased in 17 (61%), increased in 1 (4%), and did not change in 10 (35%).

CONCLUSION

When untethering was performed by sectioning a filum terminale, the size of terminal syringomyelia decreased in more than half of patients in the long term. Sectioning the filum terminale demonstrated the possibility of radiological and clinical improvement in patients with terminal syringomyelia.

Retethering after transection of a tight filum terminale, postoperative MRI may help to identify patients at risk

PURPOSE

Retethering after transection of a tight filum terminale (TFT) deemed to be a rare and usually only years after initial surgery occurring complication. Possible perioperative factors that might influence the retethering rate or help to allow a prognostic risk assessment are still poorly investigated. The aim of this study was to analyze our patient cohort who underwent a TFT transection by assessing clinical outcome, retethering rate, and pre- and postoperative MRI studies.

METHODS

All consecutive patients undergoing transection of a TFT from January 2011 to December 2018 were evaluated. Inclusion criteria were defined as exclusive TFT intervention and a minimum follow up period of 1 year. Epidemiological data, treatment modalities, complication characteristics, and MRI studies were recorded and analyzed.

RESULTS

A total of 58 patients met our inclusion criteria. The retethering rate in our patient cohort was 5.2% (3/58); one of the three patients developed two episodes of a retethering. Patients with an unchanged conus level, no improvement in the syringomyelia, and an unchanged thickness of the spinal cord postoperatively seem to have a significant higher risk to develop a retethering episode in the follow-up.

CONCLUSION

Retethering after transection of the filum terminale did occur more often than expected. Certain existing factors on the routine postoperative MR images may help to identify patients with an increased likelihood to develop a retethering episode. These results may contribute to improve the follow-up for patients after transection of a TFT and may facilitate adequate treatment.

Enlargement of Extraspinal Cysts in Spinal Dysraphism : A Reason for Early Untethering

Some types of spinal dysraphism can be accompanied by extraspinal cysts, including myelomeningocele, myelocystocele, myelocele, meningocele, limited dorsal myeloschisis, lipomyelomeningocele, and terminal myelocystocele. Each disease is classified according to the developmental mechanism, embryologic process, site of occurrence, or internal structure of the extraspinal cyst. In most cystic spinal dysraphisms except meningocele, part of the spinal cord is attached to the cyst dome. Most open spinal dysraphisms pose a risk of infection and require urgent surgical intervention, but when the cyst is accompanied by closed spinal dysraphism, the timing of surgery may vary. However, if the extraspinal cyst grows, it aggravates tethering by pulling the tip of the cord, which is attached to the dome of the cyst. This causes neurological deficits, so urgent surgery is required to release the tethered cord.

Radical excision of lumbosacral lipoma: an early experience of "followers"

BACKGROUND

Indication, timing, and method for surgical treatment of lumbosacral lipoma are controversial. Radical resection of the lumbosacral lipoma and complete reconstruction of the placode are supported in that better long-term outcome can be achieved without increasing complication rate compared with traditional surgical techniques.

OBJECTIVE

We analyzed the early surgical outcomes of lumbosacral lipoma treated with the untethering and radical excision of fat.

METHODS

Retrospective analysis of surgically treated 81 fresh lumbosacral lipoma cases with dorsal, transitional, and chaotic types and true lipomyelomeningocele (LMMC) was performed. Caudal and filar types were excluded.

RESULTS

Complete untethering was accomplished in 98%. Radical excision of the lipoma was attempted in all cases and achieved in 83%. Postoperative neurological complication was observed in 8 cases (10%). Group of lipoma types (dorsal + transitional vs. chaotic + true LMMC) and availability of radical lipoma excision turn out to be factors related to neurological outcomes in univariate analysis (p < 0.001 and p = 0.027, respectively). Group of lipoma types, availability of radical excision, and postoperative cord/dural sac (C/D) ratio are related factors in multivariate analysis (p = 0.025, p = 0.049, and p = 0.031).

CONCLUSIONS

As a follower of untethering and radical excision of fat, careful consideration is required to plan the surgery of lumbosacral lipoma on account of the "underestimated" complication rate. Type of the lipoma is the important factor determining the surgical outcome. Availability of complete radical excision and postoperative C/D ratio are the operative factors related to the neurological outcomes.

Human tail-like cutaneous appendage with a contiguous stalk of limited dorsal myeloschisis

PURPOSE

Limited dorsal myeloschisis (LDM) is characterized by a fibroneural stalk linking the skin lesion to the underlying spinal cord. On account of the external skin lesion, all LDMs are either flat (nonsaccular) or saccular, and a human tail-like cutaneous appendage has not been reported.

METHODS

In our 14 LDM patients, 2 had tail-like appendages. We retrospectively analyzed the relationship between the appendage and the LDM tract from the clinicopathological findings of these 2 patients.

RESULTS

Preoperative magnetic resonance imaging including three-dimensional heavily T2-weighted images demonstrated an intradural tethering tract, but failed to reveal the precise communication with the appendage. However, surgery revealed the extradural and intradural slender stalk, starting at the base of appendage and running through the myofascial defect. Histological examination demonstrated that there was a tight anatomical relationship between the fibroadipose tissue of the appendage and the fibrocollagenous LDM stalk.

CONCLUSION

When there is potential for an LDM stalk in patients with an appendage, a meticulous exploration of the stalk leading from an appendage is required. Clinicians should be aware of possible morphological variations of skin lesions associated with LDM.

Decreased MEPs during subcutaneous dissection for untethering surgery of a "true" lipomyelomeningocele: aggravated traction of the spinal cord by release of the sac from the original nest

PURPOSE

It is well known that the preoperative enlarged sac in occult spinal dysraphism, in which the spinal cord is attached to its dome, can be associated with neurological deficits by aggravation of spinal cord traction. We experienced a similar phenomenon during the early stage of untethering surgery for "lipomyelomeningocele in a strict sense (LMMC)."

CLINICAL PRESENTATION

We report a case of a 3-month-old girl with LMMC, which showed decreased motor evoked potentials (MEPs) in the lower extremities during the early stage of untethering surgery. The sac was released from the original nest by incision with separation of the overlying skin and dissection from the muscle fascia. The sac became rounder, and the spinal cord attached to the dome of the sac was further stretched. After aspiration of cerebrospinal fluid from the sac, the MEPs recovered. Postoperatively, the patient had no neurological deficits.

CONCLUSIONS

Although this phenomenon rarely occurs, release of the herniated sac of LMMC from the original nest during the early stage of untethering surgery may result in neurological changes. Application of intraoperative neurophysiological monitoring helps to detect electrophysiological deterioration and can prevent neurological deficits.

Homogeneous Spinal-Shortening Axial Decompression as a Revision Surgery After Untethering Surgery in Pediatric Patients with Tethered Cord Syndrome

OBJECTIVE

To evaluate surgical outcomes of homogeneous spinal-shortening axial decompression (HSAD) for reoperation in pediatric patients with tethered cord syndrome.

METHODS

Twenty consecutive pediatric patients (≤18 years old, 7 boys, 13 girls) who underwent HSAD after untethering surgery between June 2012 and May 2015 were included. The Japanese Orthopaedic Association score and visual analog scale were used to evaluate preoperative and postoperative neurologic function and pain. The International Consultation on Incontinence Questionnaire-Short Form and urodynamics were used to evaluate urinary function. The Rintala score was used to evaluate stool function.

RESULTS

Mean age of patients was 13.4 ± 3.6 years (range, 7-18 years). The mean duration of follow-up was 31.2 ± 12.7 months (range, 12-48 months). The Japanese Orthopaedic Association score was increased from 13.31 ± 4.03 preoperatively to 19.15 ± 4.17 at final follow-up (P < 0.01). The visual analog scale score was decreased from 5.25 ± 1.78 preoperatively to 2.21 ± 1.63 at final follow-up (P < 0.01). The International Consultation on Incontinence Questionnaire-Short Form score was decreased from 14.94 ± 4.15 preoperatively to 7.63 ± 4.40 at final follow-up (P < 0.01). All urodynamics parameters improved compared with before the operation. The Rintala score improved from 5.26 ± 3.45 preoperatively to 12.32 ± 3.43 at final follow-up (P < 0.01).

CONCLUSIONS

Outcomes of HSAD for revision surgery of tethered cord syndrome were satisfactory. HSAD improved neurologic function of patients significantly. HSAD could become an alternative surgical treatment of reoperation for tethered cord syndrome.

Surgical histopathology of limited dorsal myeloschisis with flat skin lesion

PURPOSE

Limited dorsal myeloschisis (LDM) is characterized by two invariable features: a focal closed neural tube defect and a fibroneural stalk linking the skin lesion to the underlying spinal cord. Although detailed histopathological findings of the LDM stalk were originally described by Pang et al., the precise relationship between the histopathological findings and clinical manifestations including intraoperative findings has not been fully determined.

METHODS

We retrospectively analyzed the histopathological findings of the almost entire stalk and their relevance to the clinical manifestations in six Japanese LDM patients with flat skin lesions.

RESULTS

Glial fibrillary acidic protein (GFAP)-immunopositive neuroglial tissues were observed in three of the six patients. Unlike neuroglial tissues, peripheral nerve fibers were observed in every stalk. In four patients, dermal melanocytosis, "Mongolian spot," was seen surrounding the cigarette-burn lesion. In three of these four patients, numerous melanocytes were distributed linearly along the long axis of the LDM stalk, which might represent migration of melanocytes from trunk neural crest cells during formation of the LDM stalk.

CONCLUSION

Immunopositivity for GFAP in the LDM stalk was observed in as few as 50% of our patients, despite the relatively extensive histopathological examination. We confirm that the clinical diagnosis of LDM should be made based on comprehensive histopathological examination as well as clinical manifestations. The profuse network of peripheral nerve fibers in every stalk and the high incidence of melanocyte accumulation associated with dermal melanocytosis might assist the histopathological diagnosis of LDM.

Slender Stalk with Combined Features of Saccular Limited Dorsal Myeloschisis and Congenital Dermal Sinus in a Neonate

Limited dorsal myeloschisis (LDM) and congenital dermal sinus (CDS) originate from incomplete disjunction between the cutaneous and neural ectoderms. Some LDM stalks have been found to have elements of a CDS or dermoid cyst. We surgically treated a saccular lesion in the lumbosacral region of a 7-day-old male neonate. Although fetal magnetic resonance imaging (MRI) failed to reveal a stalk, postnatal MRI including three-dimensional heavily T2-weighted imaging demonstrated a stalk originating from the lumbar cord and extending caudally to enter the lumbosacral meningocele sac. During untethering surgery, we found that the stalk was slender, with a diameter of 0.7-0.8 mm, but otherwise appeared to be a typical LDM stalk. Histopathological examination revealed that the fibrocollagenous stalk contained glial fibrillary acidic protein-immunopositive neuroglial tissues and stratified squamous epithelium. The present report describes the first documented case of a stalk with combined features of saccular LDM and CDS in a neonate. Since cutaneous ectodermal tissue is likely to remain in the remnant stalk, this patient requires careful monitoring to detect the potential development of a dermoid cyst.

Limited dorsal myeloschisis with no extradural stalk linking to a flat skin lesion: a case report

BACKGROUND

Limited dorsal myeloschisis (LDM) is characterized by a fibroneural stalk linking the skin lesion to the underlying spinal cord. CASE PRESENTATION : A 7-month-old girl with a lumbosacral "cigarette-burn" flat skin lesion underwent untethering surgery. The intradural tethering stalk appeared to originate at the dural wall and join the cord with no extradural stalk linking to the skin lesion. Histological examination of the intradural stalk revealed glial fibrillary acidic protein-immunopositive neuroglial tissues in the fibrocollagenous band, which is the central histopathological feature of an LDM stalk.

CONCLUSION

It is conceivable that the LDM stalk in our patient was originally linked to the skin lesion and subsequently regressed and was replaced by mature adipose tissue. We should be mindful of possible variations in the morphological features of LDM.

Neurosurgical pathology of limited dorsal myeloschisis

PURPOSE

The term limited dorsal myeloschisis (LDM) was used by Pang et al. (2010) to describe a distinct clinicopathological entity. LDMs are characterized by two invariable features: a focal-closed neural tube defect and a fibroneural stalk that links the skin lesion to the underlying spinal cord.

METHODS

We retrospectively analyzed the neurosurgical pathologic findings of four LDM patients.

RESULTS

Case 1 had a saccular skin lesion with nonterminal abortive myelocystocele at T11-12. Cases 2, 3, and 4 had a non-saccular (flat) skin lesion in the lumbosacral region. The morphologic features of the lesion in case 2 were those of meningocele manque. Cases 3 and 4 had accompanying non-LDM anomalies, caudal-type lipoma and type II split-cord malformation with neurenteric cyst, respectively. At preoperative diagnosis of the LDM stalk, magnetic resonance imaging, including 3D heavily T2-weighted image was useful; however, minute findings were often missed in the complicated cases 3 and 4. All patients had a favorable outcome following untethering of the stalk from the cord. The central histopathological feature of the LDM stalk is neuroglial tissue in the fibrocollagenous band; however, the stalk in cases 2 and 4 did not have glial fibrillary acidic protein-immunopositive neuroglial tissues.

CONCLUSIONS

Therefore, the diagnosis of LDM should be made based on comprehensive evaluation of histologic and clinical findings.

Lateral lipomyelomeningocele of the hemicord with split cord malformation type I revealed by 3D heavily T2-weighted MR imaging

BACKGROUND

Lipomyelomeningocele (LMMC) is defined by a low-lying tethered spinal cord protruding posteriorly from the spinal canal and terminating in a lipomatous mass in the subcutaneous meningeal sac. The coexistence of LMMC with split cord malformation (SCM) is rare.

CLINICAL PRESENTATION

We report on a patient with laterally protruded LMMC arising from the hemicord of SCM type I. Direct coronal and axial views (instead of sagittal views) of 3D heavily T2-weighted MR imaging (3D-hT2WI) clearly demonstrated the topographical relationship between both of the hemicords, the bony septum, and nerve roots in the right subcutaneous meningeal sac.

CONCLUSION

Combined use of axial and coronal images of 3D-hT2W is useful for visualization and surgery of such a complicated anomaly.

Variation in Outcome in Tethered Cord Syndrome

Study Design

Fifty patients surgically treated for tethered cord syndrome (TCS) were retrospectively studied at Liaquat National Hospital, Karachi from 2010 until 2014.

Purpose

To assess the common presentations of TCS in our part of the world and the surgical outcome of the different presentations.

Overview of Literature

TCS is a stretch-induced functional disorder of the spinal cord with its caudal part anchored by an inelastic structure, which results in characteristic symptoms and signs. Due to the variety of lesions and clinical presentations and the absence of high-quality clinical outcome data, the decision regarding treatment is difficult.

Methods

Fifty consecutive patients with TCS were reviewed retrospectively with a follow-up period of 12–48 months. The majority of the patients were 0-15 years of age with the mean age of 4 years. The presenting complaints and the associated pathologies were documented, and the patients were assessed using the new Karachi TCS severity scale for clinical assessment.

Results

Eighty five percent of the patients with thickened filum terminale improved. Sixty six percent of the patients with diastematomyelia, 60% with lipoma and only 46% with myelomeningocele showed clinical improvement postoperatively. Sixty two percent of the patients who presented with paraperesis improved following surgery while 37% remained stable and only one patient deteriorated. Back and leg pain improved in 93% of patients and 50% of patients with urinary impairment improved.

Conclusions

Outcome of patients with TCS varies according to pathology and severity of symptoms. Diastematomyelia and thickened filum had the best outcome. The Karachi TCS severity scale is a valid tool for future studies.

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.