Use of cellulose acetate millipore filters for the correct orientation of endoscopic biopsies in digestive diseases.

INTRODUCTION: Properly oriented endoscopic biopsies allow an effective assessment of some diagnostic features in non neoplastic gastrointestinal diseases. MATERIALS AND METHODS: We used cellulose acetate millipore filters (Endofilter, Bio-Optica, Milan, Italy) in order to improve the orientation of biopsies during processing. Forty biopsies were placed on filter after endoscopic sampling whereas no orientation attempt was done for other 40 filter-free biopsies (20 from esophagus and 20 from gastric antrum in each group). Both groups were compared in terms of orientation and assessability of the following morphological features: thickness of basal layer in the esophageal squamous epithelium, length of esophageal papillae, interstitial space dilatations in the esophageal squamous epithelium and gland atrophy in the gastric antrum. Both orientation and assessability of individual morphological features were graded with a score ranging from 1 (good) to 3 (poor). The impact of this procedure on costs was analysed, both in terms of material and technical workload. RESULTS: All 20 esophageal and 20 antral biopsies on filter showed acceptable (score 1 or 2) orientation. In contrast, 14/20 filter-free esophageal and 13/20 antral biopsies showed poor (score 3) orientation (p = 0.0001 for both groups). Basal layer thickness was assessable (score 1 or 2) in 20/20 esophageal biopsies on filter vs 14/20 filter-free ones (p = 0.0001) and length of papillae in 15/20 biopsies on filter vs 4/20 filter-free ones (p = 0.0002). Interstitial space dilatation assessability was not affected by orientation procedures. Gland atrophy in the antrum was assessable (score 1 or 2) in 20/20 gastric biopsies on filter vs 8/20 filter-free ones (p = 0.0001). The use of endofilters permitted the process of numerous (up to 8 for each block) samples from different biopsy sites together and produced a significant reduction in costs (18.35 in the case of 8 biopsies from 4 different biopsy sites). CONCLUSIONS: The use of millipore filters allows orientation of biopsy samples, improves the assessment of several diagnostic features in esophageal and gastric pathology and yields a significant reduction in costs when biopsies from different sites are processed together.