Measurement of XXXX during operations upon the thoracic aorta: initial clinical experience.

@entity1 @entity63 @entity16 @entity4957 @entity1498 @entity439 @entity2759 @entity451
@entity451 has been an unpredictable, devasting complication following operations upon the thoracoabdominal aorta for over 30 years. The frequency ranges from 0.5% with operations for @entity1498 to as high as 15% following surgery for thoracoabdominal @entity439 . Both uncertainty and controversy exist about the value of different protective methods during aortic crossclamping (AXC): heparinized shunts, partial bypass, and reimplantation of intercostal arteries. This report describes the authors' initial clinical experience with a highly sensitive indicator of @entity2759 , somatosensory evoked potentials (SEP) in an attempt to prevent @entity451 associated with surgical procedures on the thoracoabdominal aorta. Seven consecutive @entity1 (one @entity1498 , five @entity439 , one @entity439 ) underwent continuous operative monitoring of SEP. Cortical response to simultaneous electrical stimulation (20 mAmps, 0.6 mSec., 2.3 cps) of both the right and @entity4957 was recorded before, during, and after AXC, and following operation. When @entity63 changes were detected by SEP, increasing distal circulation by different maneuvers (heparinized shunt, femoral-femoral bypass, reimplantation of intercostal arteries) reversed these changes. In two @entity1 with @entity439 , @entity63 changes appeared within three minutes after AXC and all potentials disappeared in nine minutes. Rapid insertion of a graft (AXC 28 and 37 minutes) resulted in SEP return 40 minutes following restoration of flow. These changes were prevented by a heparinized shunt in two @entity1 , femoral/femoral bypass in one, and T8-T9 intercostal reimplantation in one. No SEP changes occurred in the @entity1 with @entity1498 . No postoperative @entity16 occurred. Continuous operative monitoring of SEP has exciting possibilities for preventing @entity451 . It is simple, highly sensitive, and seems to provide a precise measurement of adequacy of circulation to the spinal cord.
