Department of Neurosurgery, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts.
Department of Anesthesiology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts.
Neurosurgery. 2019 Aug 1;85(2):240-249. doi: 10.1093/neuros/nyy246.
While a noninvasive flow determination would be desirable in the diagnosis of cerebrospinal fluid shunt malfunction, existing studies have not yet defined a role for thermal flow detection.
To evaluate a revised test protocol using a micropumper designed to transiently enhance flow during thermal testing to determine whether thermal detection of flow is associated with progression to shunt revision surgery.
Eighty-two unique tests were performed in 71 shunts. The primary outcome, need for revision within 7 d of testing, was compared with results of micropumper-augmented thermal flow detection. Statistical analysis was based on blind interpretation of test results and raw temperature data recorded during testing.
The test was sensitive (73%) and specific (68%) in predicting need for revision, with 5.6-fold higher probability of revision when flow was not detected. Negative predictive value in our sample was 94.2%. The probability of not requiring revision increased with increasing total temperature drop. Analysis of various possible thresholds showed that the optimal temperature cutoff may be lower than suggested by the manufacturer (0.125°C vs 0.2°C).
This is the first study to report a strong association between thermal flow evaluation and a clinical impression that a shunt is not malfunctioning. The current recommended threshold may increase the false positive rate unnecessarily, and as clinicians gain experience with the method, they may find value in examining the temperature curves themselves. Multicenter studies are suggested to further define a role for this diagnostic test.
虽然在诊断脑脊液分流故障时，非侵入性流量测定是理想的，但现有的研究尚未确定热流量检测的作用。
评估使用微泵短暂增强热测试期间的流量的修订测试方案，以确定流量的热检测是否与分流器修订手术的进展相关。
在 71 个分流器中进行了 82 项独特的测试。主要结果，即测试后 7 天内需要进行修订，与微泵增强热流量检测的结果进行了比较。统计分析基于对测试结果和测试期间记录的原始温度数据的盲法解释。
该测试在预测需要修订方面具有较高的敏感性（73%）和特异性（68%），当未检测到流量时，修订的可能性增加了 5.6 倍。在我们的样本中，阴性预测值为 94.2%。不需要修订的概率随着总温度下降的增加而增加。对各种可能阈值的分析表明，最佳温度截止值可能低于制造商建议的温度截止值（0.125°C 与 0.2°C）。
这是第一项报道热流量评估与临床印象之间存在强烈关联的研究，即分流器没有出现故障。当前推荐的阈值可能不必要地增加了假阳性率，随着临床医生获得该方法的经验，他们可能会发现检查温度曲线本身的价值。建议进行多中心研究以进一步确定这种诊断测试的作用。
