Influence of preservation or perfusion of intraoperatively identified spinal cord blood supply on spinal motor evoked potentials and paraplegia after aortic surgery

Abstract

Permanent ligation of arteries supplying blood to the spinal cord in operations for aortic aneurysm can lead to spinal cord ischemia, which can result in either paraparesis or paraplegia. This report describes a rapid method of intraoperative identification of those arteries that supply the spinal cord by use of an intrathecal platinum electrode to detect hydrogen in solution that has been injected into the aortic ostia. Preservation or perfusion of those identified arteries supplying the spinal cord may decrease the rate of postoperative neurologic complications. Of 28 porcine experiments with postoperative observation for 24 hours, there were 3 initial pilot experiments in which saline saturated with hydrogen was injected into the temporarily cross-clamped aorta. Twenty animals were then randomized to (1) preservation of only the vessels sequentially identified to supply blood to the spinal cord from T-13 to L-5 (n = 10); (2) division of the vessels supplying the spinal cord (n = 10). A further five animals underwent perfusion experiments wherein the identified cord arteries were perfused by a shunt, the other nonsupply arteries were divided, and the aorta was kept clamped for 45 minutes. Spinal motor evoked potentials were elicited with an intrathecal electrode and were highly sensitive for paralysis. Paralysis occurred in 0/3 pilot (p less than 0.013 vs division); 8/10 division; 1/10 preservation (p less than 0.0017 vs division); and perfusion 1/5 (p less than 0.025 vs division). Results of a pilot study in eight humans shows that the technique can be used to rapidly identify segmental arteries supplying the spinal cord, to determine if distal perfusion is supplying the spinal cord with blood flow, and if reattached segmental arteries are patent.

Diretrizes para a cirurgia das doenças da aorta

“…169 , em estudo não controlado, tenham sugerido que a naloxona associada à drenagem de LCR possa até mesmo dispensar o reimplante de artérias intercostais, nenhum benefício desta técnica foi evidenciado em ensaio randomizado subseqüente 171 , o que torna seu uso empírico.…”

<![CDATA[<B>Guidelines for surgery of aortic diseases from Brazilian Society of Cardiovascular Surgery</B>]]>

“…Although Acher et al [143] in a non-controlled study suggested that naloxone associated with CRL drainage can even dispense with the re-implantation of intercostal arteries; no benefits of this technique were evidenced in subsequent randomized trials [166] making its use empirical.…”

Prevention of reperfusion injury of the spinal cord in aortic surgery: An experimental study

“…3,16,17 Kouchoukos 18 reported a correlation to exist between paraplegia and the time of clamping and the length of harvested aorta. However, the reimplantation of the intercostals to the graft as far as possible is one of the best methods of protection, and especially all possible intercostals and lumber arteries between T6 and L1 should be reimplanted to the graft as far as possible.…”

“…3 Different studies have been carried out about to identify the ASA and ARM and placement of clamps under these arteries. 16 Svensson et al 16 identifi ed these arteries by a special method perioperatively by which the incidence of paraplegia after their operations decreased. Yamada et al 19 preoperatively revealed the ASA, ARM, and critical intercostal arteries by magnetic resonance angiography.…”