Trephination of the equine rostral maxillary sinus: efficacy and safety of two trephine sites.

The research examines two different methods for accessing the rostral maxillary sinus in horses, a procedure called trephination, their safety and efficacy were studied using horse skulls of different ages. The rostral method was found to be more reliable and safer, though caution is recommended when the procedure is performed on horses less than or equal to the age of five due to the risk of damaging a cheek tooth.

Methodology

• The researchers used the skulls of deceased horses (40 in total) for this descriptive study.
• Two methods of rostral maxillary sinus (RMS) trephination were employed on each skull – a rostral approach and a caudal approach.
• Radiographic imaging was used to establish the accuracy of the trephination sites, checking if they were within the RMS and directly above a cheek tooth.
• Furthermore, Sinusotomy was performed on 14 of the skulls to verify the relationship between the radiographic and anatomical location of the trephination sites and also to establish the anatomical position of the maxillary septum.
• A logistic regression model was used to determine the age-related risk of the trephine site being directly over a cheek tooth.

Results

• The rostral approach of trephine site was within the RMS in 98% of skulls, while the caudal approach was successful in 68% of cases.
• Studies indicate that there is an 18% chance of the rostral site being directly above a cheek tooth compared to a 10% chance with the caudal site.
• There was a significant negative relationship between the trephine site overlying a tooth and the age of the horse for both rostral and caudal sites.
• The radiographic images were largely accurate when compared with the actual anatomical position of the maxillary septum in the skulls which underwent sinusotomy.

Conclusions

• The researchers concluded that the rostral approach to RMS trephination is more reliable and safer than the caudal approach.
• However, they also found that younger horses (i.e., less than or equal to 5 years of age) are at a higher risk of the procedure damaging a cheek tooth. Hence, they recommend the use of radiographic guidance when performing RMS trephination on horses of this age group.