Evaluation of a thoracoscopic technique using ligating loops to obtain large lung biopsies in standing healthy and heaves-affected horses.
Authors: Relave Fabien, David Florent, Leclère Mathilde, Alexander Kate, Bussières Geneviève, Lavoie Jean Pierre, Marcoux Marcel
Journal: Veterinary surgery : VS
Summary
# Editorial Summary Obtaining diagnostic lung tissue from horses with suspected respiratory disease can be challenging; thoracoscopic biopsy offers a minimally invasive alternative to open thoracotomy, but the optimal technique remains unclear. Researchers evaluated whether pre-tied ligating loops—a cost-effective method borrowed from laparoscopic surgery—could safely secure large lung biopsies in five healthy horses and six with equine asthma (heaves), the latter sampled during both remission and acute exacerbation phases. Across 22 procedures yielding 29 biopsies, the technique proved well tolerated with acceptable safety margins: whilst postoperative pneumothorax occurred in 95% of cases, it resolved radiographically within three weeks in all instances; however, a 31% complication rate (primarily ligature slippage requiring reinforcement) and significant intraoperative hypoxaemia in non-oxygen-supplemented horses warrant careful patient selection and preparation. Clinically, this approach represents a practical, affordable option for obtaining lung samples from both healthy and chronically diseased horses, though practitioners should maintain ready access to intranasal oxygen delivery systems, backup ligating loops, and alternative instrumentation to manage complications promptly and safely.
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Practical Takeaways
- •This technique is minimally invasive and relatively inexpensive for obtaining lung biopsies even in heaves-affected horses during exacerbation, but plan for a 31% complication rate and have backup instrumentation available
- •Expect postoperative pneumothorax in most cases—it's self-limiting and resolves within 3 weeks, so serial radiographs are needed for monitoring rather than intervention
- •Have intranasal oxygen supplementation available during the procedure, especially for horses with compromised respiratory function, as intraoperative hypoxemia is common without it
Key Findings
- •Thoracoscopic lung biopsy using pre-tied ligating loops was well tolerated in all 11 horses (5 normal, 6 heaves-affected) across 22 procedures with 29 total biopsies
- •Complication rate was 31% including ligature slippage (8 cases) and pulmonary hemorrhage (1 case), with most complications managed by additional ligating loops
- •Postoperative pneumothorax occurred in 21/22 procedures but resolved radiographically within 3 weeks without intervention
- •Significant decrease in PaO2 occurred intraoperatively in horses without supplemental oxygen; 6 horses required intranasal oxygen support due to hypoxemia