Destructive lesions of the proximal sesamoid bones as a complication of dorsal metatarsal artery catheterization in three horses.

This article describes a study into the rare but serious complication of destructive damage to the proximal sesamoid bones in horses due to catheterization of the dorsal metatarsal artery, commonly carried out for blood pressure monitoring during general anesthesia.

Objective and Methods of the Study

• The authors aimed to investigate the destructive lesions occurring in the proximal sesamoid bones (PSBs) of horses, as a result of the catheterization of the dorsal metatarsal artery during general anesthesia. The arterial catheterization was utilized for direct blood pressure monitoring.
• Three client-owned horses were included in the study. Diagnostic procedures post-anesthesia included radiography, ultrasonography, synoviocentesis, and arthroscopy to identify the root cause of lameness observed in these horses in the limb where blood pressure monitoring occurred.
• The duration of this retrospective study was not specified. What is known is that horses showed severe lameness within 21 days post-surgery, localized to the fetlock region of the catheterized limb.

Results and Treatment

• The specified area of lameness in the horses pointed to complications arising from the catheterization of the dorsal metatarsal artery. Antibiotic therapy was administered in response to these findings.
• Surgical debridement, a procedure to remove damaged tissue or foreign objects from a wound, was feasible in one of the horses. The other two, which had inaccessible lesions, did not respond to medical management and had to be euthanized.
• The one horse that underwent surgical debridement survived, indicating that this could be a viable treatment approach when accessible.

Conclusions and Recommendations

• The diagnosis and subsequent treatment of the destructive lesions of the PSB proved challenging. This emphasizes the need for strict aseptic measures during the insertion of arterial catheters to prevent such complications.
• A change in hospital protocol was instated to improve the aseptic technique during catheter insertion and to replace manometer tubing and heparinized saline for each newly inserted arterial catheter into the dorsal metatarsal artery. This new protocol effectively eliminated the complications observed in the study.
• The article concludes by reiterating that while focal destructive lesions of the PSB due to dorsal metatarsal arterial catheterization are rare, they remain a serious complication of equine anesthesia. Therefore, careful execution and stringent hygiene protocols should be observed every time this procedure is performed.