Koek G H, Vos R, Flamen P, Sifrim D, Lammert F, Vanbilloen B, Janssens J, Tack J
Centre for Gastroenterological Research, University Hospital Gasthuisberg, KU Leuven, Belgium.
Gut. 2004 Jan;53(1):21-6. doi: 10.1136/gut.53.1.21.
Studies combining pH and Bilitec monitoring found a high prevalence of both acid and duodeno-gastro-oesophageal reflux in severe reflux disease. Clearance of refluxed material is a major defence mechanism against reflux. Several studies have been devoted to oesophageal acid clearance but oesophageal clearance of refluxed duodenal contents (DC) has rarely been addressed.
To compare oesophageal acid and DC clearance.
Ten healthy volunteers (five women, mean age 23 (1) years) were studied. Firstly, a balloon tip catheter, positioned in the duodenum under fluoroscopy, was used to aspirate DC after stimulation by a high caloric liquid meal (200 ml, 300 kcal). During the second session, pH and Bilitec probes were positioned 5 cm above the lower oesophageal sphincter and a small infusion catheter was introduced into the proximal oesophagus. The subject was placed supine under a gamma camera. One of two different solutions (DC mixed with 0.2 mCi Tc99m pertechnetate or citric acid (pH 2) mixed with 0.2 mCi Tc99m pertechnetate) was infused into the proximal oesophagus and the subject was instructed to swallow at 20 second intervals. Clearance was assessed using scintigraphy (dynamic acquisition, one frame per second in the anterior view; calculation of time to clear peak counts to background level), pH (time to pH<4) or Bilitec (time absorbance >0.14) monitoring, with or without continuous saliva aspiration. Each condition was studied twice in a randomised design; measurement time was four minutes, interrupted by water flushing, with a two minute rest period. Results are given as mean (SEM) and were compared by Student's t test and Pearson correlation.
Scintigraphic evaluation showed a volume clearance time of 29 (3) seconds for acid and 28 (9) seconds for DC (NS). Saliva aspiration had no significant influence on volume clearance of acid or DC (28 (4) and 30 (13) seconds, respectively; NS). pH monitoring showed an acid clearance time of 217 (15) seconds, which was significantly prolonged to 324 (30) seconds during saliva aspiration (p<0.05). Bilitec monitoring showed a DC clearance time of 131 (27) seconds, which was not significantly prolonged by saliva aspiration (176 (36) seconds; p = 0.08). DC clearance was faster than acid clearance, either without or with saliva aspiration (p<0.055 and p<0.05, respectively).
Under experimental conditions, liquid acid and DC solutions have comparable volume clearances. Chemical clearance occurs slightly faster for DC than for acid, and saliva plays a major role in the clearance of acid only.
结合pH值和Bilitec监测的研究发现，在严重反流性疾病中，酸反流和十二指肠-胃-食管反流的发生率都很高。反流物质的清除是抵御反流的主要防御机制。已有多项研究致力于食管酸清除，但反流十二指肠内容物（DC）的食管清除很少被涉及。
比较食管酸清除和DC清除。
对10名健康志愿者（5名女性，平均年龄23（1）岁）进行研究。首先，在荧光透视引导下将球囊尖端导管置于十二指肠，用于在高热量流质餐（200 ml，300 kcal）刺激后抽吸DC。在第二阶段，将pH值和Bilitec探头置于食管下括约肌上方5 cm处，并将一根小输液导管插入食管近端。受试者仰卧于γ相机下。将两种不同溶液中的一种（DC与0.2 mCi高锝酸盐Tc99m混合或柠檬酸（pH 2）与0.2 mCi高锝酸盐Tc99m混合）注入食管近端，并指示受试者每隔20秒吞咽一次。使用闪烁扫描（动态采集，前视图每秒一帧；计算清除峰值计数至背景水平的时间）、pH值（pH<4的时间）或Bilitec（吸光度>0.14的时间）监测评估清除情况，有无持续唾液抽吸均可。每种情况在随机设计下研究两次；测量时间为4分钟，期间用水冲洗并休息2分钟。结果以平均值（标准误）表示，并通过学生t检验和Pearson相关性进行比较。
闪烁扫描评估显示，酸的容积清除时间为29（3）秒，DC为28（9）秒（无显著性差异）。唾液抽吸对酸或DC的容积清除无显著影响（分别为28（4）秒和30（13）秒；无显著性差异）。pH值监测显示酸清除时间为217（15）秒，在唾液抽吸期间显著延长至324（30）秒（p<0.05）。Bilitec监测显示DC清除时间为131（27）秒，唾液抽吸未使其显著延长（176（36）秒；p = 0.08）。无论有无唾液抽吸，DC清除均比酸清除快（分别为p<0.055和p<0.05）。
在实验条件下，液态酸溶液和DC溶液具有相当的容积清除率。DC的化学清除比酸略快，且唾液仅在酸清除中起主要作用。
