Objective: To evaluate the efficacy of a temporary balloon occlusion test for the prevention of paraplegia following transluminally placed endoluminal prosthetic grafts for descending thoracic aortic aneurysms.
Subjects and methods: Two occlusion balloons were inserted via the brachial and femoral arteries and positioned in the proximal and distal neck of the descending thoracic aortic aneurysms using fluoroscopy. After temporary occlusion of the thoracic aorta by inflation of both the proximal and distal balloons, the evoked spinal potential was measured for 15 mins. A maximum amplitude during temporary balloon occlusion test decreasing by more than 20% of the pre-balloon occlusion level was considered to be significant, enough to not perform transluminally placed endoluminal prosthetic grafts, but instead an open repair. The test was applied in 12 cases (9 males and 3 females, 50-86 years old). All aneurysms were located between the Th6 and Th12 with a maximum diameter of 40-70 mm, and average of 56 mm.
Results: The changes in maximum amplitude of evoked spinal potential remained within 20% of the value before balloon occlusion in 11 cases. Transluminally placed endoluminal prosthetic grafts were performed in these 11 cases and no instance of paraplegia or other complication relating to the test was observed. Deployment of stent-grafts was successful in 10 cases (91%).
Conclusion: It is suggested that the preoperative measurement of evoked spinal potential during temporary balloon occlusion is clinically useful for the assessment of the risk to paraplegia occurring in transluminally placed endoluminal prosthetic grafts.