Discontinuous myelotomy: an alternative to standard myelotomy in the surgical treatment of intramedullary spinal cord tumours.

BACKGROUND

Myelotomy is an essential step for the removal of intramedullary tumours. Often, this manoeuvre requires division of large vessels surfacing the midline, contributing to the development of postoperative sensory deficits. We developed a technique of discontinuous myelotomy to preserve the integrity of these large spinal cord vessels.

METHODS

Over a three-year period, we approached 20 intramedullary astrocytomas through a posterior myelotomy consisting of two separate incisions one above and the other below the midline vessel. The tumour was removed using the Cavitron ultrasound aspirator (CUSA), through either incision. Tumour underlying the bridging area between the two incisions was successfully removed through an oblique view.

FINDINGS

We retrospectively analysed the clinical outcome in terms of sensory function. Follow-up examinations showed that up to 70% of the patients had their sensory function unchaged. 5 (20%) patients experienced a permanent worsening of their deficits, involving superficial and deep sensation in cases 1 and 4, respectively. Two (10%) patients showed significant improvement.

INTERPRETATION

Discontinuous myelotomy is a viable technical option whenever the presence of large vessels on the median raphe would make the standard midline myelotomy unsafe.