Influence of segmental arteries, extent, and atriofemoral bypass on postoperative paraplegia after thoracoabdominal aortic operations

Purpose: The purpose of this article was to study the influence of either reattachment or oversewing of patent segmental intercostal or lumbar arteries, extent of aneurysm, and atriofemoral bypass on the incidence of postoperative paraplegia/paraparesis in patients at high risk with type I or II thoracoabdominal aneurysms. Methods: Data were prospectively collected on 99 patients undergoing type I or II thoracoabdominal aneurysm repairs, including exact extent of repair and whether atriofemoral bypass was used. Patency of intercostal arteries from T3 to T12 and lumbar arteries from L1 to L4 were checked by intraoperative inspection. If the arteries were patent, note was taken of whether they were reattached to the new aortic prosthesis. Postoperative neurologic motor function was graded daily for the first 5 days, and the worst score in the first 30 postoperative days (POD) was used for analysis. Results: Ninety-five of 99 (96%) patients were 30-day survivors. By POD 30, 31 of 98 (32%) patients had had a neurologic deficit. There was no difference in the incidence of deficits according to whether lumbar or intercostal arteries were reattached, ignoring the effect of patency of the arteries. Of greater importance, however, was whether patent segmental arteries were oversewn at specific levels. Thus, for patients who had one or more arteries at T11, T12, or L1 oversewn (often because they could not be reattached), a deficit developed in 11 of 23 (48%) patients versus 20 of 75 (27%) patients who did not have patent arteries or had all patent arteries reattached (p = 0.05, odds ratio = 2.5). More specifically, if all arteries at this level were oversewn, a neurologic deficit developed in 63% of patients versus 23% if all their arteries were reattached (p = 0.01). Reattachment of patent arteries at individual levels from T7 to L4 showed a trend toward a lower risk of deficits but did not reach statistical significance. On multivariate analysis, atriofemoral bypass was associated with a lower risk of paralysis (p = 0.068), and significantly so when controlled for age (p = 0.0329, odds ratio 0.287). Subgrouping of extent type I thoracoabdominal aneurysms resulted in an incidence of paralysis of 14% ( 3 22) for subgroup A and 23% (5 of 22) for subgroup B compared with 43% (23 of 55) for type II thoracoabdominal aneurysms (type I [8 of 44 18%], versus type II [p = 0.0097]). Conclusion: Patients with no or few patent segmental arteries in the aortic segment being replaced have a lower risk of neurologic deficits, compared with those with patent arteries. Every effort should be made to reattach all arteries at T11, T12, and L1 and, when possible within the constraints of technical feasibility and time, also those from T7 to L4. Preoperative angiography or intraoperative hydrogen testing may better identify the arteries that need to be reattached. When feasible, atriofemoral bypass appears to be protective, particularly when sequential clamping and segmental repairs can be performed.