Compared with standard colonoscopy, capsule endoscopy shows low sensitivity for detecting colonic lesions, according to a report in the July 16 issue of the New England Journal of Medicine.

Capsule endoscopy, a procedure in which the patient swallows a capsule equipped with a camera that visualizes the GI tract as it travels through, had a 64% sensitivity for detecting polyps that were 6 mm or larger and a 73% sensitivity for detecting advanced adenomas 6 mm or larger in a multicenter European study, said Dr. Andre Van Gossum of Erasme University Hospital, Brussels, and his associates.

“This study shows that capsule endoscopy is a safe method of visualizing the colonic mucosa through colon fluids without the need for sedation or insufflation,” the researchers concluded.

However, in an editorial accompanying this report, Dr. Michael Bretthauer said that the capsule’s failure to detect large polyps in 36% of the patients and its impaired ability to detect large adenomas is “cause for concern.”

Given the relatively high cost of capsule endoscopy and its requirement for more extensive bowel preparation than is needed for colonoscopy, “colon capsule endoscopy cannot be recommended at this time,” said Dr. Bretthauer of Oslo University Hospital Rikshospitalet and the Cancer Registry of Norway in Oslo.

In the study – sponsored by Given Imaging, maker of the PillCam – 328 patients who were scheduled to undergo standard colonoscopy first underwent capsule endoscopy. This required more extensive bowel preparation, including fluid administration after ingestion of the capsule to stimulate its progression through the GI tract. But it did not require the sedation or bowel insufflation needed with standard colonoscopy.

All the study subjects had known colonic disease (a history of colorectal cancer or adenomatous polyps, ulcerative colitis, or positive radiographic findings) or were suspected to have it based on signs and symptoms such as rectal bleeding, hematochezia, melena, or positive fecal occult blood test.

A total of 19 cancers were detected by colonoscopy; 14 of these also were detected by capsule endoscopy, for a sensitivity of 74% for colon malignancies, Dr. Van Gossum and his colleagues said (N. Engl. J. Med. 2009;361:264-70).

The sensitivity of capsule endoscopy was significantly affected by the quality of the colon preparation, with the poorest sensitivity occurring in cases where the lumen was partially obscured by fecal residue. In contrast, the procedure’s specificity was not affected by fecal residue.

The only adverse events reported by patients were mild and were attributable to the bowel preparation rather than to passage of the capsule itself. However, one patient was unable to swallow the PillCam, and in five others the capsule failed to reach the end of the colon before its battery ran out, rendering the examination incomplete.

In his editorial comment, Dr. Bretthauer noted that suboptimal bowel cleansing hindered imaging in 28% of the capsule endoscopies, compared with 13% of standard colonoscopies. Moreover, the more extensive bowel-cleansing regimens needed for capsule endoscopy are likely to decrease patient satisfaction with the procedure, he said (N. Engl. J. Med. 2009;361:300-1).

Colon capsule endoscopy has not been approved for use in the United States but is “actively marketed” in Europe, where the current price is about 950 euros, the equivalent of $1,150 in U.S. dollars – “not lower than the price of colonoscopy or CT colonography,” he added.

Dr. Bretthauer was the New England Journal of Medicine’s editorial fellow for 2008-2009.

Copyright (c) 2009 Elsevier Global Medical News. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.

根据7月16日出版的《新英格兰医学杂志》（New England Journal of Medicine）所刊载的文章报道，与标准结肠镜相比，应用结肠胶囊内镜检测结肠病变的敏感性较低。

 

所谓胶囊内镜检查，就是让患者吞下一个装备有相机的胶囊，当胶囊通过消化道时观察其内部情况。来自布鲁塞尔埃拉斯姆大学医院的Andre Van Gossum医生及其同事在欧洲进行了一项多中心研究，其研究结果显示，胶囊内镜检测≥6 mm息肉的敏感性为64%，检测≥6 mm进行性腺瘤的敏感性为73%。

 

研究者总结道：“此项研究显示，应用胶囊内镜，无需镇静或气腹，即可透过结肠液观察结肠黏膜，是一项安全的检测方法。”

 

然而，由Michael Bretthauer医生撰写的有关此项报道的述评指出，胶囊内镜未能检测出36%患者的大的息肉，检测大的腺瘤的能力也有不足，这些均“值得关注”。

 

Bretthauer医生就职于奥斯陆大学医院Rikshospitalet 及奥斯陆的挪威癌症登记中心。他指出，由于应用胶囊内镜的费用相对较高，而所需的肠道准备也比结肠镜要多，所以“现在还不推荐应用结肠胶囊内镜”。

 

此项研究由PillCam胶囊內镜生产商基文影像公司资助。研究者选取328名预定接受标准结肠镜检查的患者，对他们进行胶囊内镜检查。这需要更多的肠道准备，包括吞下胶囊后大量饮水，以刺激其在消化道中行进。但此种检查不用进行标准结肠镜检查所需的镇静或肠道充气。

所有参试者均有结肠疾病（包括结直肠癌或腺瘤性息肉病史、溃疡性结肠炎，或有Ｘ线阳性发现）或因出现直肠出血、便血、黑便或粪便隐血试验阳性等体征和症状而怀疑有结肠疾病。

 

Van Gossum医生及其同事指出，通过结肠镜共检测出19例癌症患者，而其中14例同时经由胶囊内镜检测出，故胶囊内镜检测结肠恶性肿瘤的敏感性为74%（N. Engl. J. Med. 2009;361:264-70）。

 

胶囊内镜检查的敏感性受到结肠准备质量的显著影响，在那些管腔因粪便残留造成部分区域模糊的病例中，其敏感性最差。相反，粪便残余并不会影响其特异性。

 

患者报告的仅有的不良反应较为缓和，均来自于肠道准备过程，而非胶囊通过过程本身。然而，有1名患者不能吞下PillCam胶囊内镜，其他5名患者服下的胶囊在电池用尽后仍未到达结肠末端，故检查未能完成。

 

Bretthauer医生在其述评中强调，因肠道净化不充分造成成像障碍的比例，在胶囊内镜检查中为28%，而在标准结肠镜检查中仅为13%。更重要的是，胶囊内镜检查所需的更多的肠道净化方案可能会减低患者对该检查程序的满意度（N. Engl. J. Med. 2009;361:300-1）。

 

他提出，结肠胶囊内镜检查在美国尚未获批准，而在欧洲则正“积极上市”，在那里现在的价格约为950欧元，相当于1150美元，“并不比结肠内镜或CT结肠成像检查价格便宜。”

 

Bretthauer医生是《新英格兰医学杂志》2008～2009年度的编委。

 

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