title: The rat esophagus: ultrastructure and radiological aspects of tissue response after 1320 nm Nd:YAG laser irradiation.
abstract: Morphological tissue response towards laser treatment was investigated in the esophagi of adult Wistar rats by light- and transmission electron microscopy. The specimens were fixed by perfusion immediately, 2 days and 14 days after laser treatment in order to assess different stages of the healing process. The epithelium of the lasercentre was completely destroyed in the immediate group. The connective tissue showed damaged cells, fused collagenous fibres and occluded blood vessels. Smooth muscle cells presented a vacuolated sarcoplasm and pycnotic nuclei. The cross striation of skeletal muscle cells had disappeared and their nuclei were karyolytic. In a distance of 4 mm from the lasercentre all wall tissues had an almost normal appearance. After 2 days the morphological feature of the lasercentre was the same as in the immediate group. In a distance of 2 mm some layers of flat and intact epithelial cells were observed below the necrotic epithelium. The adjacent connective tissue was infiltrated by inflammatory cells. After 14 days the formation of granulation tissue had caused an occlusion of the lumen in the lasercentre. In a distance of 2 mm the lumen was patent and the wall tissues had been partly restored. As the rat esophagus serves as a model for esophagotracheal fistulae in newborn children we assume the 1320 nm Nd:YAG laser to be a possible application in occlusion of these fistulae.
authors.affiliation: Clinic of Pediatric Surgery, University of Münster, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Schaarschmidt
authors.forename: U
authors.initials: U
authors.lastname: Stratmann
authors.forename: R R
authors.initials: RR
authors.lastname: Lehmann
authors.forename: H
authors.initials: H
authors.lastname: Heinze
authors.forename: G H
authors.initials: GH
authors.lastname: Willital
authors.forename: E
authors.initials: E
authors.lastname: Unsöld
mesh_terms: D000818:Animals; D004848:Epithelium / Q000473:pathology / Q000528:radiation effects / Q000648:ultrastructure; D004940:Esophageal Stenosis / Q000209:etiology*; D004947:Esophagus / Q000000981:diagnostic imaging / Q000473:pathology / Q000528:radiation effects* / Q000648:ultrastructure; D053685:Laser Therapy; D007834:Lasers / Q000009:adverse effects*; D008297:Male; D008854:Microscopy, Electron; D011859:Radiography; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors