Spinal Cord Complications After Thoracic Aortic Surgery: Long-Term Survival And Functional Status Varies With Deficit Severity

Mark F Conrad, Jason Y Ye, Thomas K Chung, J Kenneth Davison, Richard P Cambria.
Massachusetts General Hospital, Boston, MA.

OBJECTIVES: Paraplegia after thoracoabdominal aneurysm (TAA) repair has been associated with poor survival. However, little information exists concerning the spectrum of severity characterizing spinal cord ischemic complications (SCI). The goal of this study is to stratify SCI by deficit severity in an attempt to determine differences in late survival and function.

METHODS: A review of our prospectively maintained thoracic aortic database was performed from 5/87 - 12/05 in order to identify patients who experienced SCI of any extent after TAA repair. During this period, 576 patients underwent descending thoracic aortic repair [93 open, 105 endovascular (TEVAR)] or open TAA repair (279 extent I - III and 99 extent IV). In an effort to stratify severity of SCI, we created a Spinal Cord Ischemia Deficit (SCID) scale, which is defined as: I. flaccid paralysis, II. Average neurological muscle grade indicating < 50% function and III. Average neurological muscle grade indicating > 50% function. Long-term outcomes were evaluated in relation to these groups by actuarial methods.

RESULTS: 64 (11.1%) patients developed SCI of any severity during the study period [7/105 (6.6%) TEVAR, 57/471 (12%) open]. These were stratified by SCID level: I: 24 (37.5%), II: 31 (48.4%) and III: 9 (14.1%). SCI was immediate in 33 (54.1%) patients and presented in a delayed fashion in 28 (45.9%). The majority of SCI associated with TEVAR were delayed (6/7). The 30-day mortality was significantly higher in the SCI group than the overall patient cohort [15/64 (23.4%) vs 41/512 (8%), p<0.001) and varied by SCID level [I: 11/24 (45.8%), II: 4/31 (12.9%), III: 0/9 (0%), p=0.001]. The 5-year actuarial survival for all SCI was lower than for non-SCI patients (25%+6 vs 51%+3, p<0.001) and indeed, varied linearly with SCID level. However, there was no difference between SCID II/III and the non-SCI patients (41%+10 vs 51%+3, p=0.281). There were no SCID I patients alive at 5 years. While no patients with SCID I recovered the ability to walk, 8/11 (73%) of SCID II and 9/9 (100%) of SCID III could ambulate with/without assistance.

CONCLUSIONS: Survival and functional outcomes correlate with SCI severity. Patients with SCID I have a poor long-term outlook while SCID II/II I patients have a survival that is similar to non-SCI patients and most recover the ability to ambulate.