Surgical technique of temporary arterial occlusion in the operative management of spinal hemangioblastomas.
Spinal hemangioblastomas (SH) are definitively treated by en bloc microsurgical resection. Although benign, their highly vascular nature makes resection challenging. A major difficulty involves intraoperative differentiation of vessels supplying the tumor from those supplying the spinal cord. Twenty patients with SH treated surgically at a single institution were reviewed. Median age was 49 years (range 24 to 70 years). Eleven patients had von Hippel-Lindau syndrome. Six underwent preoperative angiography, of which five underwent embolization. All tumors were posterior and resected through a laminectomy approach. Temporary arterial occlusion (TAO) by aneurysm clip placement with concurrent neuromonitoring was used at the tumor edge to differentiate arteries supplying the tumor from those supplying the healthy spinal cord. Arteries were assumed to not supply important regions of the cord and divided at the tumor surface if there was no change in evoked potentials after 4 minutes of occlusion. Of the 20 patients, 5 improved, 13 remained stable, and 2 worsened. Of the five treated with TAO, two improved, three remained stable, and none worsened. Median McCormick's functional grade of patients treated with TAO was II and improved to I after the operation, whereas that of those not treated with TAO remained unchanged at II (Wilcoxon rank-sum, P = .35). Temporary arterial occlusion with neuromonitoring is a safe, effective, and simple method of differentiating arteries supplying the tumor only from those that supply the functionally normal spinal cord in the operative management of difficult SH.