Anatomy of the vestibulum esophagi and surgical implications during prosthetic laryngoplasty in horses.

This research investigates the anatomy of the vestibulum esophagi (the entry to the horse’s esophagus) and assesses the risk of damaging it during a laryngoplasty surgery. The study finds that understanding the anatomy of the vestibulum esophagi reduces the possibility of puncturing it during the surgery.

Study Design and Methodology

• The researchers conducted an ex vivo cadaveric study, in which they examined the anatomy of the vestibulum esophagi in five isolated horse larynges and 39 horse head and neck specimens.
• The vestibulum esophagi’s anatomy was studied by dissecting five cadaver specimens first.
• Following this, a bilateral laryngoplasty was performed. This included placing sutures through the muscular processes in various directions using both straight and curved needles.
• The surgical procedures were performed by three surgeons, two of whom were not aware of the study’s goals. This setup was likely to simulate the potential real-world ignorance of surgeons regarding the vestibulum esophagi.
• After the surgery, the positions of the sutures and any damage to the vestibulum esophagi were identified by dissecting the specimens.

Results of the Study

• The study found that the vestibulum esophagi spans the width of the larynx, connecting both wings of the thyroid cartilage and covering the rostral spine of the arytenoid cartilages.
• Incidents of adventitia (the outermost layer of the esophagus) penetration were significantly higher, attaining 72%, when the surgeons were unaware of the anatomical extent of the vestibulum esophagi. In contrast, the surgeon who knew about the study recorded only a 9% penetration rate.
• The lumen (inner space) of the vestibulum esophagi was punctured in only 4.6% of suture placements, and all occurrences were done by the two surgeons unaware of the study’s goals.

Conclusions

• The study concludes that penetrating the esophagus’ adventitia layer is more likely when surgeons lack knowledge about the anatomy of the vestibulum esophagi.
• It highlighted that comprehensive anatomical knowledge of the vestibulum esophagi can help reduce the incidences of puncturing its lumen and adventitia during suture placements on the muscular process of the arytenoid cartilage, suggesting that educating surgeons about this could minimize complications during laryngoplasty in horses.