Aspectos morfológicos da bulla tympanica de cães após osteotomia restrita ventral e lateral

Abstract

O objetivo deste trabalho foi investigar os aspectos morfológicos da bulla tympanica após osteotomia ventral e lateral. Quarenta cães adultos foram distribuídos em dois grupos de 20 animais cada. No grupo A , os animais foram submetidos a osteotomia ventral da bulla tympanica e no grupo B, a osteotomia lateral da bulla tympanica. Cada grupo foi constituído de 2 subgrupos, de acordo com o período de observação: A1 e B1 (6 semanas), A2 e B2 (12 semanas). No exame macroscópico constatou-se que a concavidade de todas as bullae tympanicae operadas era semelhante às normais. Os estudos histológicos mostraram que a regeneração completa da bulla tympanica ocorreu em apenas alguns animais de cada subgrupo. A presença de tecido conjuntivo na área de osteotomia foi verificada na maioria das bullae tympanicae operadas, resultado estatisticamente significante. A análise histológica e a histomorfometria computadorizada não mostraram diferença significante quanto ao estágio de regeneração óssea em todos os subgrupos. Concluiu-se que uma área de ostetomia restrita não causou alterações significantes na conformação da bulla tympanica de cães submetida a osteotomia ventral ou lateral; e que a regeneração total da bulla tympanica geralmente não ocorreu antes de 12 semanas de pós-operatório.

Morphological aspects of tympanic bulla after ventral osteotomy in cats

“…Previous reports in dogs found similar results. 8,13 The macroscopic exams revealed that the concavity of the operated bullae were similar to the normal ones, with preservation of the tympanic cavity. Just a slight protuberance in the inner surface of the larger compartment was detected in most of the operated bullae (Figure 3).…”

“…The anatomic changes that occur with healing of ventral tympanic bulla osteotomy have been studied in dogs, whose bulla consists of a single compartment. 7,8 Although the crescent clinical application, we did not find experimental studies about this surgery in cats. Therefore, in this study, our objective was to evaluate the morphology of the tympanic bulla after experimental ventral osteotomy in cats by radiographic, macroscopic, histolopathological and histomorphometric exams.…”

“…This abnormalities were probably masked by the overlap of cranial bones as described in a previous report on dogs submitted to experimental unilateral ventral osteotomy. 8 On the other hand, openmouth and oblique lateral radiographs afforded better visualization of the tympanic bulla, detached from the other cranial bones. This allowed detection of some features, but only in some of the oblique lateral radiographs.…”

“…This is inconsistent with a previous experimental study in dogs, in which the interruption in the contour of the tympanic bulla was seen more frequently on radiographs done in oblique lateral view. 8 But the adequacy of the radiographic plane may be related to bulla anatomy, and since the tympanic bulla of the cat seems shallower than that of the dog, the open mouth radiography may better reveal its features. The open-mouth radiographs taken immediately after surgery showed an interruption in the contour of the larger bulla compartment in 4 operated cats of A1 group and 6 of the A2 group (Figure 2).…”

“…Similar results were found in dogs submitted to experimental ventral osteotomy. 8 Bulla radiography is often useful in evaluating middle-ear diseases. Radiographic evidences of bulla diseases include densities in the tympanic cavity and thickening of the bulla wall.…”