Laparoscopic closure of the vaginal ring in adult stallions to prevent strangulated indirect inguinal herniation (SIIH)

Closing the vaginal ring in stallions is indicated in those stallions that were treated for a SIIH without being castrated.

In our caseload, only 24% of the stallions treated for a SIIH are castrated. The majority of those castrated stallions are not castrated for medical issues related to SIIH but castration is requested by the owner because of behaviour problems and/or not being good enough to be accepted as a stallion in the Belgian Studbooks.

Between 2000 and 2015, 165 stallions were treated for a SIIH at our hospital and 102 horses were discharged from the hospital without being castrated. Those stallions are at risk of re-herniation within the following month or years and laparoscopic closure of the vaginal rings is recommended to the owner.

Closure of the vaginal ring can only be performed laparoscopically and a couple of techniques have been described over the last 20 years1-4 .

What did we learn over the last 20 years ?

• Closure of the entire vaginal ring (also the caudal part) is mandatory to minimize the risk of re-occurrence.
• Foreign material (mesh plugs) within the inguinal canal should be avoided. Fibrotic reaction around blood vessels and nerves can cause fertility, testicular atrophy and chronic groin pain.
• A tension free closure of the vaginal ring should be the aim in sport horses (athletes).
• A hernioplasty (covering the vaginal ring) is recommended over a herniorraphy (suturing/stapling)
• In large vaginal ring (> 6 cm) a peritoneal flap hernioplasty may not be strong enough and a mesh hernioplasty should be considered.
• A detailed topographic knowledge of the inguinal anatomy is lacking. This knowledge is needed to operate safely in the danger zone, the area caudal to the mesorchium and this to avoid chronic groin pain caused by vascular and neurological damage during surgery.

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