Prone: Patients are positioned prone; all pressure points are protected.
Skin incision includes sinus tract: The tract is totally excised from the skin orifice to the point of termination. Incomplete resection of the tract without intradural exploration is insufficient (1).
Laminectomy/laminotomy to resect tract and expose intradural component: Osteoplastic laminotomy is considered when long exposure is needed to expose the entire dermal sinus tract or associated pathologies.
Intradural repair: Other than tract resection, surgery includes repair of all associated intradural anomalies, cord untethering, and removal of inclusion tumors and abscesses (16). Occasionally, firm attachment prevents complete resection of a dermoid cyst or tumor (23).
Cultures: If tumor or abscess is encountered, tissue sampling for culture is important to determine antibiotic sensitivity.
Laminotomy or laminectomy: The laminar roof is removed to expose the dural sleeve. The author prefers an osteoplastic laminotomy, feeling that it may decrease the risk of delayed spinal deformity. In some cases this may be difficult when the sinus tract extends through a lamina and not an interspace.
Dissection around the tract and intradural lesions: The tract is freed from surrounding epidural structures and the dura opened using an elliptical incision around the point where the tract penetrates the dura. The tract is then separated from other intradural structures.
Complete removal of tract: Total resection of the tract and associated dermoid or epidermoid tumors decreases the risk of recurrence.
Routine dural closure: Dural closure is important to prevent postoperative leakage. A dural substitute may be needed for coverage of space left after cutting out the tract as it penetrates the dura.
Lamina: The laminar roof is repositioned and sutured in place when a laminotomy is performed. Alternatively, miniplates and screws or resorbable plates and pins can be used to reattach the laminar roof.