Bioptic techniques in flexible endoscopy. An experimental study in the pig.

Low success rates in biopsies of submucosal gastric lesions have been reported. We undertook an experimental study in the pig of three different and commonly used bioptic techniques to test their ability to provide submucosal material using spiked as well as nonspiked biopsy forceps. The best results were obtained using the Crosta technique where the overlying mucosa is excised using a diathermy snare and biopsies are taken from the bared underlying tissue. The hole-in-hole technique of Seifert and the ethanol injection technique of Asaki were inferior as to bioptic depth but not in size of the biopsies. Biopsy forceps with a central spike were slightly superior to those without.