Safety and efficacy of a minimally invasive cell sampling device ('Cytosponge') in the diagnosis of esophageal pathology: a systematic review.

Esophageal adenocarcinoma is an increasingly common cause of morbidity and mortality in developed countries. Most cases are considered the consequence of chronic gastroesophageal reflux disease, with subsequent Barrett's metaplasia and dysplasia. Because progression from Barrett's metaplasia to cancer occurs over many years, endoscopic screening and surveillance programs have been established, albeit with little or no consideration for cost-effectiveness. As an alternative to the expensive and resource-demanding endoscopic surveillance, the Cytosponge has been developed to sample the esophageal mucosa efficiently. The device is a compressed mesh sponge encapsulated in an ingestible gelatin pill attached to a string. After swallowing, the capsule dissolves allowing the sponge to expand in the stomach. As it is pulled out, cells are collected from the esophagogastric junction and throughout the esophagus. The cellular samples can be analyzed by cytology, immunohistochemistry, and molecular markers. We conducted a systematic review of all recent relevant studies to help define the role of this novel technology, including studies of screening and surveillance of Barrett's esophagus, esophageal squamous dysplasia detection, detection of eosinophilic esophagitis, and evaluation of benign esophageal diseases. With the major limitation that most studies were performed by a single investigative group that developed the technology, the device yielded overall impressive results against the endoscopy/biopsy gold standard. Patient acceptability was high. If these promising early results are validated by other investigators in other populations, the Cytosponge represents an important new advance in the detection of esophageal pathology that could potentially decrease the burden of endoscopic esophageal sampling.