Anatomical and histological study of the dorsal and ventral nasal conchal bullae in normal horses

Abstract

The morphology of the dorsal conchal bulla (DCB) and ventral conchal bulla (VCB) are poorly described. The recent recognition that these bullae can become infected, causing chronic unilateral nasal discharge, has stimulated interest in these structures. Fourteen cadaveric horse heads were transected sagittally midline and dissected to expose the nasal conchal bullae. The dimensions of each bulla, the number and orientation of drainage apertures, and cellulae septae were recorded. Randomly selected samples were examined histologically. The mean DCB and VCB lengths were 78 and 57 mm, respectively; equivalent to 13.9 per cent and 10.2 per cent of skull length, respectively. The mean DCB and VCB heights were 29 and 28 mm, respectively; equivalent to 5.2 per cent and 5 per cent of skull length, respectively. The DCB was larger than the VCB, containing more septae, cellulae and drainage apertures. No communications were identified between the bullae and the immediately adjacent paranasal sinuses. Histology revealed that the bullae consist of ciliated, pseudostratified, columnar epithelium over glandular submucosa often overlying turbinate bone and, variably, hyaline cartilage. This more detailed description of equine DCB and VCB anatomy will hopefully facilitate successful treatment of their disorders.

Radiographic identification of the equine dorsal and ventral nasal conchal bullae

“…In fact, their anatomy is usually very similar, but never identical (Froydenlund et al . ). In this study, it was also noted that the mucosal folds that delineate the rostral border of the VCB could present some differences in shape and thickness between individual horses.…”

“…) has recently ignited an interest in the anatomy and clinical imaging of these structures (Froydenlund et al . ; Liuti et al . ).…”

“…A larger number of heads aged <5 years may have provided more consistent data on size and appearance of the VCB in young horses, nevertheless similar age related variations in dimensions of the VCB have previously been described (Froydenlund et al . ; Liuti et al . ).…”

“…'s paper (), and two other papers by the same group describing the gross, histological (Froydenlund et al . ) and computed tomographic (Liuti et al . ) anatomy of the DCB and VCB have therefore created new interest in these structures from equine clinicians.…”

Surgical enlargement of the nasomaxillary aperture and transnasal conchotomy of the ventral conchal sinus: Two surgical techniques to improve sinus drainage in horses

“…An increased resistance at the tip of the conchotome when extending the incision rostrally indicates the proximity of the conchotome blade to the rostral aspect of the VCS. Attempts to extend the conchotomy beyond this point will cause profuse bleeding in clinical cases and increase the risk for postoperative infection of the ventral conchal recess and bulla located rostrally to the VCS. Limiting the caudorostral distance of the TCVCS incision to approximately 5 cm helped avoid this complication in this study.…”