Division of Gastroenterology and Hepatology, Dartmouth-Hitchcock Medical Center, Lebanon, NH, USA. Division of Gastroenterology, University of Michigan, Ann Arbor, MI, USA.
Am J Gastroenterol. 2018 Nov;113(11):1613-1620. doi: 10.1038/s41395-018-0230-5. Epub 2018 Aug 31.
Balloon expulsion testing (BET) is recommended to evaluate for dyssynergic defecation in patients with chronic constipation (CC). However, it remains poorly standardized and is limited to specialized centers. Our goal was to assess the clinical utility of balloon expulsion as an initial test for dyssynergic defecation and to determine appropriate testing parameters.
We performed a literature search to identify cohort studies of unselected subjects with CC and case-control studies of subjects with/without dyssynergic defecation. We defined dyssynergic defecation by constipation symptoms and a positive reference test (anorectal manometry [ARM], defecography, or electromyography [EMG]). We performed a meta-analysis using a bivariate mixed-effects regression model to assess summary sensitivity, specificity, and area under the curve (AUC) with 95% confidence intervals (CI). We conducted a meta-regression to investigate individual test parameters and demographic variables.
We identified 15 eligible studies comprising 2090 individual assessments of BET. Among cohort studies, the AUC was 0.80 (95% CI: 0.61-0.91) with 70% sensitivity (95% CI: 52-83%) and 77% specificity (95% CI: 70-82%). In pooling cohort and case-control studies, the AUC was 0.84 (95% CI: 0.68-0.93) with 70% sensitivity (95% CI: 53-82%) and 81% specificity (95% CI: 75-86%). Subject positioning (seated vs. left lateral decubitus) did not significantly affect test performance in cohort (p = 0.82) or case-control (p = 0.43) analysis. Most studies evaluated 50-60 mL water insufflation. Test performance was not significantly affected by varying the maximum allowed expulsion time between 1 to 5 min. Age and gender likely accounted for significant study heterogeneity between studies. Choice of reference test, continent of study, and year of study did not significantly affect test performance.
We report an optimized BET protocol. The performance characteristics of BET could support its use as a point of service test to screen for dyssynergic defecation in chronically constipated subjects.
球囊排出试验（BET）被推荐用于评估慢性便秘（CC）患者的协同性排便障碍。然而，它仍然缺乏标准化，并且仅限于专门的中心。我们的目标是评估球囊排出作为协同性排便障碍初始测试的临床实用性，并确定适当的测试参数。
我们进行了文献检索，以确定患有 CC 的未选择的受试者的队列研究和患有/不患有协同性排便障碍的受试者的病例对照研究。我们通过便秘症状和阳性参考测试（直肠测压[ARM]、排粪造影术或肌电图[EMG]）来定义协同性排便障碍。我们使用双变量混合效应回归模型进行荟萃分析，以评估汇总敏感性、特异性和曲线下面积（AUC），置信区间（CI）为 95%。我们进行了荟萃回归分析，以研究个体测试参数和人口统计学变量。
我们确定了 15 项符合条件的研究，包括 BET 的 2090 项单独评估。在队列研究中，AUC 为 0.80（95%CI：0.61-0.91），敏感性为 70%（95%CI：52-83%），特异性为 77%（95%CI：70-82%）。在合并队列和病例对照研究中，AUC 为 0.84（95%CI：0.68-0.93），敏感性为 70%（95%CI：53-82%），特异性为 81%（95%CI：75-86%）。体位（坐位与左侧卧位）在队列（p=0.82）或病例对照（p=0.43）分析中对测试性能没有显著影响。大多数研究评估了 50-60ml 水注入。在 1 至 5 分钟之间改变最大允许排出时间，对测试性能没有显著影响。年龄和性别可能是研究之间存在显著异质性的原因。参考测试的选择、研究所在的大陆和研究年份并没有显著影响测试性能。
我们报告了一个优化的 BET 方案。BET 的性能特征可以支持其作为一种服务点测试，用于筛选慢性便秘患者的协同性排便障碍。
