Subarachnoid-subarachnoid bypass versus extradural decompression for adhesive syringomyelia: experimental and early...

Adhesive syringomyelia (SM) is associated with cerebrospinal fluid (CSF) obstruction in the spinal subarachnoid space (SAS). Recurrent obstruction after decompression or arachnoidolysis may limit surgical efficacy, making the durable surgical management of adhesive SM an important challenge in neurosurgery.

Rats with MRI-confirmed SM were allocated to S-S bypass, extradural decompression, or vehicle treatment; sham-operated rats served as additional controls. Outcomes included MRI, blinded behavioral assessment, histology, and CT and fluorescent tracer studies. A prospective uncontrolled series of 14 selected patients evaluated technical feasibility, short-term safety, and clinical and radiological changes.

In the rat model, S-S bypass was associated with greater syrinx regression and more favorable behavioral and histological outcomes than extradural decompression. Distal tracer passage was also improved, whereas scar-associated tissue and recurrent SAS narrowing were observed after extradural decompression. Clinically, all 14 procedures were completed without major complications. At final follow-up, 13 patients were descriptively classified as improved and one as stable, accompanied by modest increases in ASIA sensory and motor scores.

In this rat model, S-S bypass produced more favorable structural and functional outcomes than extradural decompression by providing an alternative pathway across the obstructed segment. The preliminary clinical series supports the technical feasibility and short-term safety of the procedure, but its clinical effectiveness requires confirmation in larger controlled studies.