Reduction of neurologic injury after high-risk thoracoabdominal aortic operation. Cerebrospinal fluid drainage reduces paraplegia after thoracoabdominal aortic aneurysm repair: results of a randomized clinical trial. A prospective randomized study of cerebrospinal fluid drainage to prevent paraplegia after high-risk surgery on the thoracoabdominal aorta.
Of all aortic operations, thoracoabdominal aortic repairs have the highest risk of spinal cord neurologic injury, manifest by lower limb paraplegia or paraparesis. Cerebrospinal fluid drainage combined with intrathecal papaverine (CSFDr + IP) may reduce the risk and severity of neurologic injury. The objective of this study was to evaluate the effect of CSFDr + IP to prevent neurologic injury after high-risk thoracoabdominal aneurysm repairs.
                We screened 64 patients before operation with descending thoracic or thoracoabdominal aneurysms for possible inclusion in a prospective, randomized study. Thirty-three patients with high-risk type I and II thoracoabdominal aneurysms met inclusion criteria and 17 were randomly assigned to CSFDr + IP and 16 to the control group. The study was terminated early after interim analysis revealed a significant difference.
                Of 64 patients screened, 2 patients died after operation (3.1%, 2/64); both were in the randomized study (6%, 2/33), and neither had a neurologic injury. Neurologic injury developed in 2 CSFDr + IP patients and 7 control patients (p = 0.0392). Control patients also had lower postoperative motor strength scores (p = 0.0340). On multivariate analysis, risk factors for neurologic injury included (p < 0.05) longer cross-clamp time, failure to actively cool with bypass, and postoperative hypotension, whereas CSFDr + IP was protective. Logistic regression showed that CSFDr + IP and active cooling significantly reduced the risk of injury and that the two combined modalities were additive. Of 64 patients screened, only 2 (3%) had a permanent neurologic deficit preventing ambulation.
                For high-risk thoracoabdominal aneurysms, CSFDr + IP was effective in reducing the incidence and severity of neurologic injury. Active cooling may be further additive to CSFDr + IP protection, although this needs to be confirmed in a larger study. Despite the use of various strategies for the prevention of spinal cord ischemia, paraplegia and paraparesis continue to occur after thoracoabdominal aortic aneurysm (TAAA) repair. Although cerebrospinal fluid drainage (CSFD) is often used as an adjunct for spinal cord protection, its benefit remains unproven. The purpose of this randomized clinical trial was to evaluate the impact of CSFD on the incidence of spinal cord injury after extensive TAAA repair.
                After randomization, 145 patients underwent extent I or II TAAA repairs with a consistent strategy of moderate heparinization, permissive mild hypothermia, left heart bypass, and reattachment of patent critical intercostal arteries. The repairs were performed with CSFD (n = 76) or without CSFD (n = 69). In the former group, CSFD was initiated during the operation and continued for 48 hours after surgery. The target CSF pressure was 10 mm Hg or less.
                The two groups had similar risk factors for paraplegia. Aortic clamp time, left heart bypass time, and number of reattached intercostal arteries were also similar in both groups. Thirty-day mortality rates were 5.3% (four patients) and 2.9% (two patients) for CSFD and control groups, respectively (P =.68). Nine patients (13.0%) in the control group had paraplegia or paraparesis develop. In contrast, only two patients in the CSFD group (2.6%) had deficits develop (P =.03). No patients with CSFD had immediate paraplegia. Overall, CSFD resulted in an 80% reduction in the relative risk of postoperative deficits.
                Perioperative CSFD reduces the rate of paraplegia after repair of extent I and II TAAAs. This article is concerned with the study of the effect of several variables, principally that of cerebrospinal fluid drainage, on the incidence of neurologic deficit in a prospective randomized series of patients with extensive aneurysms of the descending thoracic and abdominal aorta (thoracoabdominal type I and II). Forty-six patients had cerebrospinal fluid drainage, and 52 were controls, with a total of 98 available for study. Cerebrospinal fluid pressure was continuously monitored in the former group and pressure maintained less than or equal to 10 mm Hg in 20, less than or equal to 15 mm Hg in 20, and greater than 15 mm Hg in 6 patients during period of aortic clamping. The method of treatment including reattachment of intercostal and lumbar arteries (p = 0.2), temporary atriofemoral bypass during aortic occlusion (p = 0.3), and spinal fluid drainage (p = 0.8) were not statistically significant in reducing the incidence of neurologic deficits. Thus cerebrospinal fluid drainage as we used it, was not beneficial in preventing paraplegia. On appropriate statistical analysis we found that the only significant predictor of delayed deficits was postoperative hypotension (p = 0.006).
There are limited data supporting the role of CSFD in thoracic and thoracoabdominal aneurysm surgery for prevention of neurological injury. Further clinical and experimental studies are indicated.