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.