Microsurgical Untethering of Pediatric Lipomyelomeningocele: A Stepwise, Photo-Illustrated Technical Note

Lipomyelomeningocele (LMMC) is one of the most common forms of occult spinal dysraphism, with an estimated incidence of 3-6 per 100,000 live births, and microsurgical untethering remains the cornerstone of management for symptomatic and selected at-risk children. The operation is technically demanding: reported rates of long-term symptomatic re-tethering after partial resection still reach 15-25%, and the surgeon must balance adequate untethering against preservation of the placode and lumbosacral nerve roots. In this technical note, we present a stepwise, illustrated description of our institutional 14-step microsurgical technique for pediatric LMMC. Each step is anchored to a defined anatomical landmark, beginning with a midline skin incision planned away from the anal verge and proceeding through subtotal subcutaneous lipoma resection, identification of the dural penetration site, a limited rostral laminectomy over normal anatomy, dural opening with circumferential dissection of lipoma-dura-cord adhesions, exploitation of the arachnoid-dura plane, electrophysiologically guided debulking of the intradural lipoma, stimulation-controlled division of the fatty filum, pia-to-pia reconstruction of the placode with 8-0 monofilament suture, expansile duraplasty with an artificial dural substitute, and reinforced multilayered watertight closure. Technical pearls aimed at minimizing the risks of cord injury, cerebrospinal fluid leak, and postoperative re-tethering are highlighted at each stage, and the role of multimodal intraoperative neurophysiological monitoring is emphasized. This note is intended as a practical, image-anchored operative reference for pediatric neurosurgeons and trainees managing this challenging closed neural tube defect.