Studies of acid exposure immediately above the gastro-oesophageal squamocolumnar junction: evidence of short segment reflux
Studies of acid exposure immediately above the gastro-oesophageal squamocolumnar junction: evidence of short segment reflux
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DOI：
10.1136/gut.2003.022160
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发表时间：
2004-02-01
期刊：
影响因子：
24.5
通讯作者：
McColl, KEL
中科院分区：
文献类型：
--
作者：
Fletcher, J;Wirz, A;McColl, KEL
背景和目的：食管pH值通常从食管下括约肌上方5厘米处记录。然而，反流性食管炎和肠化生的粘膜改变往往影响食管远端和靠近鳞状柱连接处的部分。本研究旨在探讨食管酸暴露于靠近鳞柱交界处的鳞状黏膜。方法：对11例内镜阴性消化不良患者进行双通道24小时pH监测，常规食管pH测定无胃食管反流迹象。食管pH值记录电极放置在离鳞柱连接处5毫米和55毫米处。我们开发了一种新的技术，使用金属夹子将pH导管固定在食管粘膜上并保持电极位置。食管测压显示远端电极位于食管下括约肌的高压区。结果：我们发现24小时食管酸暴露（百分比时间pH，4）比常规位置（近5 cm）高出5 mm （11.7% vs 1.8%; p < 0.001）。在直立（12.7% v 2.3%）和仰卧（10.5% v 1.3%）以及餐前（14.2% v 1.6%）和餐后（21.8% v 2.8%）期间，远端酸暴露明显高于传统部位（p均为0.001）。靠近鳞状柱连接处记录的反流事件数量也高于常规位置（168 v 33; p, 0.001）。这两个地点的酸暴露没有相关性。结论：食管最末端的鳞状黏膜暴露于大量的酸性反流，即使在没有常规反流疾病证据的患者中也是如此。这种短段反流可以解释胃-食管交界处化生和瘤变的高发。
Background and aims: Oesophageal pH is conventionally recorded from a point 5 cm above the lower oesophageal sphincter. However, the mucosal changes of reflux oesophagitis and intestinal metaplasia tend to affect the segment of oesophagus distal to this and close to the squamocolumnar junction. This study set out to investigate oesophageal acid exposure of squamous mucosa close to the squamocolumnar junction.Methods: Dual channel 24 hour pH monitoring was carried out in 11 patients with endoscopy negative dyspepsia and no evidence of gastro-oesophageal reflux by conventional oesophageal pH metry. Oesophageal pH was recorded from electrodes positioned 5 mm and 55 mm proximal to the squamocolumnar junction. A novel technique was developed using metal clips to secure the pH catheter to the oesophageal mucosa and maintain these electrode positions. Oesophageal manometry indicated that the distal electrode was within the high pressure zone of the lower oesophageal sphincter.Results: We found that 24 hour oesophageal acid exposure ( per cent time pH,4) was greater 5 mm above the squamocolumnar junction compared with the conventional position 5 cm more proximal (11.7% v 1.8%; p < 0.001). The greater acid exposure at the distal versus the conventional site was apparent in both the upright (12.7% v 2.3%) and supine (10.5% v 1.3%) positions, as well as during preprandial (14.2% v 1.6%) and postprandial (21.8% v 2.8%) periods ( p, 0.001 for each). The number of reflux events recorded close to the squamocolumnar junction was also higher than at the conventional position ( 168 v 33; p, 0.001). There was no correlation between acid exposure at the two sites.Conclusions: The squamous mucosa of the most distal oesophagus is exposed to substantial acidic reflux, even in patients without evidence of conventional reflux disease. This short segment reflux may explain the high incidence of metaplasia and neoplasia at the gastro-oesophageal junction.