title: Modification of surgical procedure for "probable" limited dorsal myeloschisis.
abstract: OBJECTIVE Since the entity limited dorsal myeloschisis (LDM) was proposed, numerous confusing clinical cases have been renamed according to the embryopathogenesis. However, clinical application of this label appears to require some clarification with regard to pathology. There have been cases in which all criteria for the diagnosis of LDM were met except for the presence of a neural component in the stalk, an entity the authors call "probable" LDM. The present study was performed to meticulously review these cases and suggest that a modified surgical strategy using limited laminectomy is sufficient to achieve the surgical goal of untethering. METHODS The authors retrospectively reviewed the imaging findings, operative notes, and pathology reports of spinal dysraphism patients with subcutaneous stalk lesions who had presented to their institution between 2010 and 2014. RESULTS Among 33 patients with LDM, 13 had the typical nonsaccular lesions with simple subcutaneous stalks connecting the skin opening to the spinal cord. Four cases had "true" LDM meeting all criteria for diagnosis, including pathological confirmation of CNS tissue by immunohistochemical staining with glial fibrillary acidic protein. There were also 9 cases in which all clinical, imaging, and surgical findings were compatible with LDM, but the "neural" component in the resected stalk was not confirmed. For all the cases, limited exposure of the stalk was done and satisfactory untethering was achieved. CONCLUSIONS One can speculate based on the initial error of embryogenesis that if the entire stalk were traced to the point of insertion on the cord, the neural component would be proven. However, this would require an extended level of laminectomy/laminotomy, which may be unnecessary, at least with regard to the completeness of untethering. Therefore, the authors propose that for some selected cases of LDM, a minimal extent of laminectomy may suffice for untethering, although it may be insufficient for diagnosing a true LDM.
authors.affiliation: Divisions of 1 Pediatric Neurosurgery and.|Department of Anatomy, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Ji Yeoun
authors.initials: JY
authors.lastname: Lee
authors.affiliation: Divisions of 1 Pediatric Neurosurgery and.
authors.forename: Sangjoon
authors.initials: S
authors.lastname: Chong
authors.affiliation: Pediatric Radiology, Seoul National University Children's Hospital.
authors.forename: Young Hun
authors.initials: YH
authors.lastname: Choi
authors.affiliation: Divisions of 1 Pediatric Neurosurgery and.
authors.forename: Ji Hoon
authors.initials: JH
authors.lastname: Phi
authors.affiliation: Pediatric Radiology, Seoul National University Children's Hospital.
authors.forename: Jung-Eun
authors.initials: JE
authors.lastname: Cheon
authors.affiliation: Divisions of 1 Pediatric Neurosurgery and.
authors.forename: Seung-Ki
authors.initials: SK
authors.lastname: Kim
authors.affiliation: Department of Pathology, Seoul National University Hospital; and.
authors.forename: Sung Hye
authors.initials: SH
authors.lastname: Park
authors.affiliation: Pediatric Radiology, Seoul National University Children's Hospital.
authors.forename: In-One
authors.initials: IO
authors.lastname: Kim
authors.affiliation: Divisions of 1 Pediatric Neurosurgery and.
authors.forename: Kyu-Chang
authors.initials: KC
authors.lastname: Wang
mesh_terms: D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007796:Laminectomy / Q000379:methods*; D008297:Male; D012189:Retrospective Studies; D016135:Spinal Dysraphism / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*
keywords: CNS = central nervous system; EMG = electromyography; GFAP = glial fibrillary acidic protein; IHC = immunohistochemistry; LDM = limited dorsal myeloschisis; UDS = urodynamic study; laminectomy; limited dorsal myeloschisis; modified surgical procedure; spine