Expanding Ventricular Diverticulum Overlying the Cerebral Hemisphere through an Open-Lip Schizencephalic Cleft: A Report of Two Pediatric Cases.

INTRODUCTION: Open-lip-type schizencephaly is characterized by trans-cerebral clefts filled with cerebrospinal fluid (CSF) between the subarachnoid space at the hemisphere surface and the lateral ventricles. Disorders related to CSF retention, including hydrocephalus and arachnoid cysts, have reportedly been associated with open-lip schizencephaly and have induced intracranial hypertension in some cases. However, detailed neuroimaging and surgical treatment findings have rarely been described. CASE PRESENTATION: We report 2 cases of open-lip schizencephaly with an expanding CSF-filled cavity overlying the ipsilateral cerebral hemisphere that manifested as signs of intracranial hypertension. Detailed three-dimensional heavily T2-weighted imaging revealed thin borders between the CSF-filled cavity and the subarachnoid space, but no separating structures between the cavity and the lateral ventricle, suggesting that the cavity was directly connected to the lateral ventricle through the schizencephalic cleft but not to the subarachnoid space. Neuroendoscopic observation in case 1 confirmed this finding. Endoscopic fenestration of the cavity to the prepontine cistern was ineffective in case 1. Shunting between the lateral ventricle (case 1) or CSF-filled cavity (case 2) and the peritoneal cavity slightly decreased the size of the CSF-filled cavity. DISCUSSION: We speculate that the thin borders along the margin of the CSF-filled cavity are membranes that previously covered the schizencephalic cleft and are now pushed peripherally. In addition, we believe that the cavity is a ventricular diverticulum protruding through the cleft and that shunting operation is effective against such expanding cavity. Detailed magnetic resonance imaging can be useful for evaluating patients with schizencephaly associated with CSF retention disorders.

Retained Medullary Cord Associated with Terminal Myelocystocele and Intramedullary Arachnoid Cyst.

INTRODUCTION: The retained medullary cord (RMC) is a newly defined entity of closed spinal dysraphism that is thought to originate from regression failure of the medullary cord during the last phase of secondary neurulation. The terminal myelocystocele (TMC) is an unusual type of closed spinal dysraphism, characterized by localized cystic dilatation of the terminal part of the central canal that then herniates through a posterior spinal bifida. The co-occurrence of RMC and TMC is extremely rare. CASE PRESENTATION: We treated a baby girl with a huge sacrococcygeal meningocele-like sac with two components. Untethering surgery and repair surgery for the sac revealed that RMC, associated with intramedullary arachnoid cyst (IMAC), was terminated at the bottom of the rostral cyst, forming the septum of the two cystic components, and the caudal cyst was TMC derived from the central canal-like ependymal lining lumen (CC-LELL) of the RMC at the septum. IMAC within the RMC communicated with TMC, and both contained xanthochromic fluid with the same properties. CONCLUSION: We speculated that the mass effect of the coexistent IMAC impeded the flow of cerebrospinal fluid in the CC-LELL within the RMC and eventually formed a huge TMC. In surgical strategies for such complex pathologies, it is important to identify the electrophysiological border between the functional cord and nonfunctional RMC and the severe RMC to untether the cord, as with a typical or simple RMC.

Measuring Quality of Care for Ischemic Stroke Treated With Acute Reperfusion Therapy in Japan　- The Close The Gap-Stroke.

BACKGROUND: In Japan there is no consensus on how to efficiently measure quality indicators (QIs), defined as a standard of care, for acute ischemic stroke (AIS). Using information from a health insurance claims database and electronic medical records, we evaluated the feasibility and validity of measuring QIs for AIS patients who received intravenous recombinant tissue plasminogen activator (IV rt-PA) or endovascular therapy (EVT).Methods and Results:AIS patients receiving rt-PA or EVT between 2013 and 2015 were identified. We selected 17 AIS QI measures for primary stroke centers (PSCs) and 8 for comprehensive stroke centers (CSCs). Defined QIs were calculated for each hospital and then averaged. In total, the data of 8,206 patients (rt-PA 83.7%, EVT 34.9%) from 172 hospitals were obtained. Median National Institute of Health Stroke Scale score at admission was 14, and 37.7% of the patients were functionally independent at discharge. All target QIs were successfully measured with fewer missing values, and the accuracy of preset data was about 90%. Adherence rates were low (<50%) in 5 QI measures among PSCs, including door-to-needle time ≤1 h, and in 1 QI measure among CSCs (door-to-brain and vascular imaging time ≤30 min). CONCLUSIONS: Measuring QIs for AIS by this novel approach was feasible and reliable in the provision of a national benchmark.

Ruptured dermoid cyst of the conus medullaris in the myelomeningocele sac revealed at the initial repair surgery.

BACKGROUND: Dermoid cysts in the myelomeningocele (MMC) site are thought to arise in a delayed fashion because of iatrogenic implantation of dermoid elements at the time of the initial repair surgery. However, there have been few reports on dermoid elements already present at birth. CLINICAL PRESENTATION: We report a patient, in whom dermoid cyst was located at dorsal aspect of the conus medullaris in the MMC sac. Between 23+3 and 24+4 weeks of gestation, rupture of the MMC sac occurred. At this time of gestation, we speculate that rupture of the dermoid cyst also occurred and dissemination of the cyst contents caused chemical arachnoiditis in the MMC sac. At the age of 1 day, surgery to repair MMC and postoperative histological findings revealed these rare pathologies. CONCLUSION: Physicians should be aware of the possibility of rupture of a dermoid cyst in the MMC sac during fetal period.

Development of Quality Indicators of Stroke Centers and Feasibility of Their Measurement Using a Nationwide Insurance Claims Database in Japan　­ J-ASPECT Study ­

BACKGROUND: We aimed to develop quality indicators (QIs) related to primary and comprehensive stroke care and examine the feasibility of their measurement using the existing Diagnosis Procedure Combination (DPC) database. METHODS AND RESULTS: We conducted a systematic review of domestic and international studies using the modified Delphi method. Feasibility of measuring the QI adherence rates was examined using a DPC-based nationwide stroke database (396,350 patients admitted during 2013-2015 to 558 hospitals participating in the J-ASPECT study). Associations between adherence rates of these QIs and hospital characteristics were analyzed using hierarchical logistic regression analysis. We developed 17 and 12 measures as QIs for primary and comprehensive stroke care, respectively. We found that measurement of the adherence rates of the developed QIs using the existing DPC database was feasible for the 6 QIs (primary stroke care: early and discharge antithrombotic drugs, mean 54.6% and 58.7%; discharge anticoagulation for atrial fibrillation, 64.4%; discharge antihypertensive agents, 51.7%; comprehensive stroke care: fasudil hydrochloride or ozagrel sodium for vasospasm prevention, 86.9%; death complications of diagnostic neuroangiography, 0.4%). We found wide inter-hospital variation in QI adherence rates based on hospital characteristics. CONCLUSIONS: We developed QIs for primary and comprehensive stroke care. The DPC database may allow efficient data collection at low cost and decreased burden to evaluate the developed QIs.

Glial fibrillary acidic protein immunopositive neuroglial tissues with or without ependyma-lined canal in spinal lipoma of filar type: Relationship with retained medullary cord.

Background: Retained medullary cord (RMC) and filar lipomas are believed to originate from secondary neurulation failure; filar lipomas are reported to histopathologically contain a central canal-like ependyma-lined lumen with surrounding neuroglial tissue with ependyma-lined central canal (NGT w/E-LC) as a remnant of the medullary cord, which is a characteristic histopathology of RMC. With the addition of glial fibrillary acidic protein (GFAP) immunostaining, we reported the presence of GFAP-positive NGT without E-LCs (NGT w/o E-LCs) in RMC and filar lipomas, and we believe that both have the same embryopathological significance. Methods: We examined the frequency of GFAP-positive NGT, with or without E-LC, in 91 patients with filar lipoma. Results: Eight patients (8.8%) had NGT w/E-LC, 25 patients (27.5%) had NGT w/o E-LC, and 18 patients (19.8%) had tiny NGT w/o E-LC that could only be identified by GFAP immunostaining. Combining these subgroups, 56% of the patients (n = 51) with filar lipoma had GFAP immunopositive NGT. Conclusion: The fact that more than half of filar lipomas have NGT provides further evidence that filar lipoma and RMC can be considered consequences of a continuum of regression failure that occurs during late secondary neurulation.

Preoperative evaluation and surgical strategies for craniocervical junction dural arteriovenous fistula with multiple feeders: case report and review of the literature.

Craniocervical junction dural arteriovenous fistula (CCJDAVF) fed by bilateral vertebral arteries (VAs) is extremely rare. We report a case of a 63-year-old man presenting with progressive myelopathy caused by a CCJDAVF, which was fed by bilateral VAs and occipital and ascending pharyngeal arteries with multiple shunting points and that drained into intracranial sinus and spinal veins. The dural arteriovenous fistula (DAVF) was successfully treated surgically using stepwise indocyanine green (ICG) videoangiography. After surgery, the DAVF disappeared and myelopathy was markedly improved. We show detailed preoperative images and intraoperative findings of this rare DAVF and emphasize the importance of selective angiography for preoperative evaluation of feeding arteries and the usefulness of intraoperative ICG videoangiography for both identification of the fistula and confirmation of its obliteration.

Retained medullary cord and caudal lipoma with histopathological presence of terminal myelocystocele in the epidural stalk.

Background: The retained medullary cord (RMC), caudal lipoma, and terminal myelocystocele (TMCC) are thought to originate from the failed regression spectrum during the secondary neurulation, and the central histopathological feature is the predominant presence of a central canal-like ependyma-lined lumen (CC-LELL) with surrounding neuroglial tissues (NGT), as a remnant of the medullary cord. However, reports on cases in which RMC, caudal lipoma, and TMCC coexist are very rare. Case Description: We present two patients with cystic RMC with caudal lipoma and caudal lipoma with an RMC component, respectively, based on their clinical, neuroradiological, intraoperative, and histopathological findings. Although no typical morphological features of TMCC were noted on neuroimaging, histopathological examination revealed that a CC-LELL with NGT was present in the extraspinal stalk, extending from the skin lesion to the intraspinal tethering tract. Conclusion: This histopathological finding indicates the presence of TMCC that could not be completely regressed and further supports the idea that these pathologies can be considered consequences of a continuum of regression failure during secondary neurulation.

Histopathological presence of dermal elements in resected margins of neural structures obtained from initial repair surgery for myelomeningocele.

Background: Development of dermoid or epidermoid cysts in myelomeningocele (MMC) sites is generally thought to occur in a delayed fashion due to implantation of dermal elements during initial repair surgery. Another theory is that dermal and dermoid elements may already be present within dysplastic neural structures at birth. Methods: We experienced histopathological presence of dermal elements in resected tissues at initial repair surgery in four out of 18 cases with MMC who required resection of parts or margins of the neural structures to perform cord untethering. Since one of these cases has already been reported, we describe the clinicopathological findings for the remaining three cases. Results: In Case1, cryptic dermoid elements were discovered in the terminal filum-like structure (FT-LS) caudal to the open neural placode (NP). The FT-LS had histopathological characteristics similar to the retained medullary cord. In Case 2, dermoid elements were discovered in the caudal margin of the dysplastic conus medullaris. In Case 3, a thin squamous epithelial layer overlapped the rostral margin of the NP where the NP was located near the skin. Case 1 developed an epidermoid cyst at 1 year and 2 months of age, which was totally resected. Conclusion: Prenatally existing cryptic dermoid elements in the caudal portion of neural structures and remnants of dermal elements overlapping the rostral margin of the NP are associated with delayed occurrence of dermoid/ epidermoid cysts. Postoperative histopathological investigation of the resected specimens is recommended. Once dermal elements are revealed, repeated imaging examination and additional surgery should be considered.

Ectopic dorsal root ganglion in cauda equina mimicking schwannoma in a child.

Background: A heterotopic dorsal root ganglion (DRG) is sometimes observed in the vicinity of dysplastic neural structures during surgery for open spinal dysraphism; however, it is rarely associated with closed spinal dysraphism. Distinguish from neoplasms by preoperative imaging study is difficult. Although the embryopathogenesis of a heterotopic DRG has been speculated to be migration disorder of neural crest cells from primary neural tube, its details remain unelucidated. Case Description: We report a pediatric case with an ectopic DRG in cauda equina associated with a fatty terminal filum and bifid sacrum. The DRG mimicked a schwannoma in the cauda equina on preoperative magnetic resonance imaging. Laminotomy at L3 revealed that the tumor was entangled in the nerve roots, and small parts of the tumor were resected for biopsy. Histopathologically, the tumor consisted of ganglion cells and peripheral nerve fibers. Ki-67 immunopositive cells were observed at the periphery of the ganglion cells. These findings indicate the tumor comprised DRG tissue. Conclusion: We report detailed neuroradiological, intraoperative and histological findings and discuss the embryopathogenesis of the ectopic DRG. One should be aware of the possibility of ectopic or heterotopic DRGs when cauda equina tumors are observed in pediatric patients with neurulation disorders.

Severe type of segmental spinal dysgenesis with complete disconnection of the spinal cord and vertebra associated with open neural tube defect.

Background: Severe type of segmental spinal dysgenesis (SSD) is a rare and complex anomaly in which the spinal cord completely disconnects at the portion of the spinal dysgenesis. Although closed spinal dysraphisms have been associated with SSD, to the best of our knowledge, the association between open neural tube defect (ONTD) and SSD is significantly rare, with only one case being reported to date. Case Description: We report a case of an infant with severe SSD and a disconnected spinal cord and spinal column at the thoracolumbar junction associated with myelomeningocele (MMC) in the lumbosacral region. The patient presented severe neurological deficits in the legs and impaired bowel function. The spinal column of L1-L3 was absent. The lower spinal segment consisted of neural placode at the L5-S1 level and no connecting structure between the upper and lower spinal cords. A repair surgery for MMC, including cord untethering and dura plasty, was performed. Histopathological findings revealed a neural placode consisting of a neuroglial tissue and leptomeninges. Conclusion: The management of severe SSD during the perinatal period is more challenging when it is associated with ONTD. We report detailed neuroradiological, intraoperative, and histological findings of such a case and discuss the embryopathogenesis of the associated ONTD and the treatment strategies.

Intramedullary abscess at thoracolumbar region transmitted from infected dermal sinus and dermoid through retained medullary cord.

BACKGROUND: A retained medullary cord (RMC) is a relatively newly defined entity of closed spinal dysraphism that is thought to originate from regression failure of the medullary cord during secondary neurulation. A congenital dermal sinus (CDS) may provide a pathway for intraspinal infections such as repeated meningitis. Intramedullary abscesses are the rarest but most serious complication of a CDS. CASE DESCRIPTION: We treated a female infant with an intramedullary abscess in the thoracolumbar region, which was caused by infection of the CDS. Surgery revealed that the cord-like structure (C-LS) started from the cord with the intramedullary abscess, extended to the dural cul-de-sac, and further continued to the CDS tract and skin dimple. The boundary between the functional cord and the non-functional CL-S was electrophysiologically identified, and the entire length of the C-LS (the RMC) with an infected dermoid cyst was resected. As a result, the abscess cavity was opened and thorough irrigation and drainage of the pus could be performed. Histopathological examination of the C-LS revealed an infected dermoid cyst and abscess cavity with keratin debris in the fibrocollagenous tissue. The abscess cavity had a central canal-like ependymal lined lumen (CCLELL), with surrounding glial fibrillary acidic protein (GFAP)-immunopositive neuroglial tissues. CONCLUSION: We demonstrated that the transmission of an infection through the RMC was involved in the development of the intramedullary abscess. A good postoperative outcome was obtained because a terminal ventriculostomy for pus drainage could be achieved by excising the nonfunctional RMC.

Influence of hospital capabilities and prehospital time on outcomes of thrombectomy for stroke in Japan from 2013 to 2016.

To determine whether increasing thrombectomy-capable hospitals with moderate comprehensive stroke center (CSC) capabilities is a valid alternative to centralization of those with high CSC capabilities. This retrospective, nationwide, observational study used data from the J-ASPECT database linked to national emergency medical service (EMS) records, captured during 2013-2016. We compared the influence of mechanical thrombectomy (MT) use, the CSC score, and the total EMS response time on the modified Rankin Scale score at discharge among patients with acute ischemic stroke transported by ambulance, in phases I (2013-2014, 1461 patients) and II (2015-2016, 3259 patients). We used ordinal logistic regression analyses to analyze outcomes. From phase I to II, MTs increased from 2.7 to 5.5%, and full-time endovascular physicians per hospital decreased. The CSC score and EMS response time remained unchanged. In phase I, higher CSC scores were associated with better outcomes (1-point increase, odds ratio [95% confidence interval]: 0.951 [0.915-0.989]) and longer EMS response time was associated with worse outcomes (1-min increase, 1.007 [1.001-1.013]). In phase II, neither influenced the outcomes. During the transitional shortage of thrombectomy-capable hospitals, increasing hospitals with moderate CSC scores may increase nationwide access to MT, improving outcomes.

Osteosarcoma of the temporal bone occurring 40 years after radiotherapy: A technical case report presenting en bloc resection of intra- and extracranial lesions followed by a one-stage reconstruction.

BACKGROUND: Osteosarcoma (OS) is a malignant tumor of the bone, which rarely occurs in the head-and-neck regions as a primary or a secondary malignancy. Adequate surgical resection is currently the mainstay of treatment for head-and-neck OS; however, en bloc resection and reconstruction can be difficult because the anatomies of these regions are complex. We present a case of an OS arising from the temporal bone 40 years after radiation therapy, which was successfully treated with en bloc resection and a one-stage reconstruction using intraoperative tissue expansion technique. CASE DESCRIPTION: A 62-year-old woman who underwent surgery and radiotherapy for a left temporal lesion 40 years before presentation was hospitalized for aphasia and a right hemiparesis. She had a 4 × 3 cm subcutaneous mass in the left temporal area of the head. Computed tomography imaging showed destruction of the left temporal bone and a partially calcified mass. Magnetic resonance imaging showed an enhancing mass with intracranial and extracranial cystic components (5 cm and 3 cm in diameter, respectively). Due to rapid growth of the lesion, a semi-urgent surgery was performed. In this operation, a continuous narrow craniectomy was performed around the tumor using a ruler. Then, en bloc resection of the tumor, with adjacent skin, temporal muscle, skull, dura mater, and cerebral cortex, was achieved. Subsequently, a one-stage reconstruction of the dura mater, skull, and skin of the head was performed using fascia lata, artificial bone, and a local skin flap combined with intraoperative tissue expansion using a 20-French Foley catheter. Postoperative histological examinations revealed the tumor to be an OS. CONCLUSION: We have presented a rare case of an OS occurring from the temporal bone 40 years after radiation therapy. We describe our experience and the surgical methods in this case to provide options for surgical strategies in patients with head-and-neck OS.

Two cases of retained medullary cord running parallel to a terminal lipoma.

BACKGROUND: Retained medullary cord (RMC) is a newly defined entity believed to originate from the late arrest of secondary neurulation. Some RMCs contain varying amounts of lipomatous tissues, which need to be differentiated from spinal lipomas, such as filar and caudal lipomas (terminal lipomas). CASE DESCRIPTION: We surgically treated two patients with a nonfunctional cord-like structure (C-LS) that was continuous from the cord and extended to the dural cul-de-sac, and ran parallel to the terminal lipoma. In both cases, untethering surgery was performed by resecting the C-LS with lipoma as a column, under intraoperative neurophysiological monitoring. Histopathological examination confirmed that the central canal-like ependyma-lined lumen with surrounding neuroglial and fibrocollagenous tissues, which is the central histopathological feature of an RMC, was located on the unilateral side of the resected column, while the fibroadipose tissues of the lipoma were located on the contralateral side. CONCLUSION: Our findings support the idea proposed by Pang et al. that entities such as RMC and terminal lipomas are members of a continuum of regression failure occurring during late secondary neurulation, and the coexistence of RMC and terminal lipoma is not a surprising finding. Therefore, it may be difficult in clinical practice to make a distinct diagnosis between these two entities.

Saccular Limited Dorsal Myeloschisis with Spinal Cord Deviation out of the Spinal Canal to the Sac.

Saccular limited dorsal myeloschisis (LDM) is characterized by a fibroneural stalk linking the saccular skin lesion to the underlying spinal cord. Since untethering surgery during the early postnatal period is often indicated to prevent sac rupture, saccular LDM should be distinguished from myelomeningocele (MMC) during the perinatal period. We treated two patients with the spinal cord deviation from the spinal canal to the sac, which mimicked a prolapse of the neural placode into the MMC sac. In patient 1, pre- and postnatal magnetic resonance imaging (MRI) revealed that the spinal cord was strongly tethered to the thick stalk. During surgery, the dorsally bent cord and stalk were united, and the border between these two was determined with intraoperative neurophysiological mapping (IONM). In patient 2, the spinal cord was tethered to two slender stalks close to each other, which was visible with the combined use of sagittal and axial postnatal three-dimensional heavily T2-weighted imaging (3D-hT2WI). The preoperative MRI hallmark of saccular LDM is the visualization of a stalk that links the bending cord and sac. Complete untethering surgery to return the cord into the spinal canal and correct its dorsal bending is recommended.

Refractory CSF leakage following untethering surgery performed 10 months after birth for enlarging terminal myelocystocele associated with OEIS complex.

Background: Terminal myelocystocele (TMC) is an occult spinal dysraphism characterized by cystic dilatation of the terminal spinal cord in the shape of a trumpet (myelocystocele) filled with cerebrospinal fluid (CSF), which herniates into the extraspinal subcutaneous region. The extraspinal CSF-filled portion of the TMC, consisting of the myelocystocele and the surrounding subarachnoid space, may progressively enlarge, leading to neurological deterioration, and early untethering surgery is recommended. Case Description: We report a case of a patient with TMC associated with OEIS complex consisting of omphalocele (O), exstrophy of the cloaca (E), imperforate anus (I), and spinal deformity (S). The untethering surgery for TMC had to be deferred until 10 months after birth because of the delayed healing of the giant omphalocele and the respiration instability due to hypoplastic thorax and increased intra-abdominal pressure. The TMC, predominantly the surrounding subarachnoid space, enlarged during the waiting period, resulting in the expansion of the caudal part of the dural sac. Although untethering surgery for the TMC was uneventfully performed with conventional duraplasty, postoperative CSF leakage occurred, and it took three surgical interventions to repair it. External CSF drainage, reduction of the size of the caudal part of the dural sac and use of gluteus muscle flaps and collagen matrix worked together for the CSF leakage. Conclusion: Preoperative enlargement of the TMC, together with the surrounding subarachnoid space, can cause the refractory CSF leakage after untethering surgery because the expanded dural sac possibly increases its own tensile strength and impedes healing of the duraplasty. Early untethering surgery is recommended after recovery from the life-threatening conditions associated with OEIS complex.

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.

Surgical histopathology of a filar anomaly as an additional tethering element associated with closed spinal dysraphism of primary neurulation failure.

BACKGROUND: Closed spinal dysraphism of primary neurulation failure could be associated with filar anomalies, such as filar lipoma or thickened and tight filum terminale (TFT), resulting from impaired secondary neurulation. Retained medullary cord (RMC) is a remnant of the cavitary medullary cord originating from the secondary neurulation failure. Some filar lipomas are known to contain a central canal-like ependyma-lined lumen with surrounding neuroglial tissues (E-LC w/NGT), that is, a characteristic histopathology of RMC. To clarify the embryological background of these filar anomalies, we evaluated the histopathological findings. METHODS: Among 41 patients with lesions of primary neurulation failure who underwent initial untethering surgery, the filum including cord-like structure (C-LS) was additionally resected in 10 patients (five dorsal and transitional lipomas; five limited dorsal myeloschisis). We retrospectively analyzed the clinical, neuroradiological, intraoperative, and histopathological findings. RESULTS: Among 10 patients, two patients were diagnosed with RMC based on morphological features and intraoperative neurophysiological monitoring. The diagnosis of filar lipoma was made in six patients, since various amounts of fibroadipose tissue were histopathologically noted in the filum. Two patients were diagnosed with TFT, since the filum was composed solely of fibrocollagenous tissue. E-LC w/NGT was noted not only in both C-LSs of RMCs but also in two out of six fila both with filar lipomas and fila with TFTs. CONCLUSION: These findings provide further evidence for the idea that entities, such as filar lipoma, TFT, and RMC, can be considered consequences of a continuum of regression failure occurring during late secondary neurulation.

Intraoperative Tissue Expansion Using a Foley Catheter for a Scalp Defect: Technical Note.

BACKGROUND: Primary closure of the surgical wound during neurosurgical procedures is sometimes difficult because of limited ability to expand the scalp, or because the skin defect is large. Hence, our institution recently adopted the technique of intraoperative tissue expansion using a Foley catheter for these cases. We describe this easily accomplished, readily available, effective, economical technique and describe our experience performing the technique. METHODS: With this procedure, the subcutaneous tissue (usually the subperiosteal layer) surrounding the skin defect is dissected to make a subcutaneous pocket in which to place a 20-French Foley catheter. The standard expander is a 30-mL balloon. The catheter is inserted into the subcutaneous pocket, and the balloon is inflated with 10-30 mL of saline for 5 minutes, after which the balloon is deflated for 3 minutes in a cyclic loading manner. After sufficient expansion, the primary closure of the surgical wound is achieved with minimal tension on the surrounding skin. RESULTS: Between November 2018 and February 2020, we performed this technique in 5 patients, each with a large surgical defect in the scalp. Primary closure was achieved, and postoperative wound healing was excellent in all 5 patients. CONCLUSIONS: Intraoperative skin expansion using a Foley catheter-which is easily performed, readily available, and economical-can be used to achieve surgical wound closure during various neurosurgical procedures.