Respiratory Surgery

Respiratory surgery is mainly performed to correct conditions within the upper respiratory tract and the larynx. These conditions are usually diagnosed endoscopically but some may the use of a dynamic overland endoscope as they can only be visualised during exercise. These procedures include:

1. Hobday – this is the removal of the lateral ventricles and the vocal folds of the larynx and is performed on horses with mild recurrent laryngeal neuropathy (whistling) This technique produces a scar within the larynx which will hold it open. The surgery can either be performed through a laryngotomy (hole cut over the larynx) with the horse anaesthetised or endoscopically with a laser under heavy sedation.

2. Prosthetic laryngoplasty (Tie back) – this is for more severe cases of recurrent laryngeal neuropathy (roaring) and involves placing a prosthetic suture on the dorsal surface o the larynx on the left side to hold the arytenoids cartilage in an abducted position. This process is usually combined with a hobday. Up until recently this procedure was performed under general anaesthesia but a technique has now been developed to do it  in the standing sedated horse.

This procedure does come with a degree of risk with the potential for food to be inhaled into the trachea post surgery and the horse to develop a persistent cough. It is has also been recognised that the prosthesis may fail and for the condition to reoccur.

3. Neuropedical graft – this is a new technique where nerves from an adjacent muscle are taken and implanted into the muscle which with stimulation begins to regenerate and perform its normal function. This technique is still under review but holds hope for the future.

4. Thermocautery of the soft palate – this procedure is used to correct dorsal displacement of the soft palate (gargling or swallowing the tongue) and involves burning the tissue of the soft palate either with a heated rod or a laser to create a scar and to stiffen the soft palate.

5. Tie forward – this is also used for correction of dorsal displacement of the soft palate and involves placement of a suture between the larynx and the hyoid bones which anchors the larynx further forward and prevents the soft palate from displacing. This is usually performed in conjunction with thermocautery of the soft palate.

6. Freeing of the epiglottis from entrapment – the epiglottis may become entrapped within a fold of mucosa from the floor of the pharynx preventing the soft palate engaging with the epiglottis.This surgery is performed in the standing sedated horse with a guarded blade. In some case a cyst may form beneath the epiglottis which can either be removed through a laryngotomy or with a laser.

7. Sinus flap surgery – this may be performed for a number of conditions including:-

• Primary sinusitis
• Upper cheek tooth problems
• Sinus cysts

This involves either the removal of or creating a flap of bone over the affected sinus and then relevant surgery performed. In most cases a separate trephine hole will be made to allow flushing of the sinus post surgery.

It is relatively common for some breakdown of the wound into the sinus to occur with further surgeries to repair any defect possible.

8. Guttural pouches (the tubes between the back of the throat and the middle ear) 

Tympany is a condition in which there is a faulty valve at the entrance to this tube causing it to fill with air. Surgery involves removal of a small area of tissue at the tube entrance to relieve this condition.

Guttural pouch mycosis – a fungal growth within the guttural pouch can cause catastrophic or even fatal nosebleeds. Surgery can be performed to ligate the affected blood vessels