Interruption of the bilateral segmental arteries at several levels : Influence on vertebral blood flow

在多血管脊柱肿瘤患者中，术中出血有时是巨大的，特别是在根治性切除术中，如脊柱全块切除术。新的栓塞术的发展确保了脊柱肿瘤的术前栓塞术更具侵袭性、更广泛、更安全。对12只雌性犬在1~3个节段的T12椎动脉结扎后，测量T12椎体血流量。在此过程中记录了脊髓冷诱发电位。另10只犬在切断双侧节段动脉后，用硅化合物行脊髓血管造影术。结扎双侧T12椎段动脉后，T12椎体血流量下降至对照组的70.13±6.37%，结扎双侧T12节段动脉后，T12椎体血流量下降至46.48±8.97%，结扎T11、12、13节段动脉后，T12椎体血流量分别下降至24.±8.31%。结扎和切开T12及T12两个平面后的血管造影显示T12节段动脉远端切开处有较厚清晰的造影剂。然而，在三个节段(T11、12和13节段)中断后，血管造影上可见T12节段动脉远端被切断的细小而微弱的信号。结扎三个水平的节段性动脉后，6只犬的SCEP均无明显变化。阻断双侧双侧节段动脉，1个靶椎体和2个相邻椎体，使犬下胸椎的靶椎体血流量降至对照值的1/4。这一结果提示，在高血管脊柱肿瘤全椎体切除术中，术前在肿瘤椎体及其上下三个平面进行栓塞术可以有效地引导术中出血。

Intraoperative hemorrhage can be sometimes massive in patients with hypervascular spinal tumors, especially in radical resection such as total en bloc spondylectomy. The recent development of new embolization techniques ensures mole aggressive, more extensive, and safer preoperative embolization for spinal tumors. The blood flow of the T12 vertebra of twelve female dogs was measured after ligation of the bilateral segmental arteries at one to three levels, including the T12. Spinal cold evoked potentials were recorded in this procedure. Spinal angiography using a silicon compound was performed on other ten dogs after clipping and section of the bilateral segmental arteries. The blood flow of the T12 vertebra decreased to 70.13±6.37% of the control value after ligation of the bilateral segmental arteries of T12, to 46.48±8.97% after ligation of the bilateral segmental arteries of T12 and either T11 or T13, to 24.±8.31% after ligation of T11, 12 and 13, respectively. The angiogram after ligation and section of T12 and the two levels including T12 showed thick and clear contrast medium in the cut distal ends of the T12 segmental arteries. After interruption at three levels (T11, 12, and 13 level), however, the,cut distal ends of the T12 segmental arteries were seen thin and faint on the angiogram. No significant changes occurred in SCEPs after ligation of the segmental arteries at three levels in all six dogs. Interruption of the bilateral segmental arteries at three levels, one target vertebra and the two adjacent vertebrae, seduced the blood flow of the target vertebra to one forth of the control value in the lower thoracic spine in dogs. This result suggests that preoperative embolization at three levels, the levels of the tumor vertebra and the adjacent vertebrae above and below it, may seduce intraoperative hemorrhage effectively during total en bloc spondylectomy for hypervascular spinal tumors