VSR 421: Regional Veterinary Surgery (2+1)

PERINEAL HERNIA

• This disease is most predominantly seen in old uncastrated male dogs. Though the condition is reported in bitches and cats, the incidence is rare.
• Etiology Weakening of the pelvic diaphragm and hernia can occur due to the following factors.
• Hormonal disorders, Prostatic diseases, Rectal diseases and Anatomical factors – rectal deviations, diverticula etc.,

Perineal hernia	Perineal hernia - Radiographic view

Symptoms

• Fluctuating /hard swelling ventral and lateral to the anus (in the ischiorectal fossa)
• Swelling may be unilateral or bilateral
• The hernial contents are usually rectum, enlarged prostate and perineal fat. Retroflexion of the bladder is not uncommon. Incarceration of bladder in the perineal hernia should be considered as an emergency.
• Hard swelling should be differentiated from perianal neoplasm.

Diagnosis

• Diagnosis should be made from clinical signs.
• Contrast radiography with barium enema will help to differentiate rectal deviation from rectal diverticulum.
• Ultra sound scan will be useful to identify a retroflexed bladder.

Surgical management

 Perineal herniarraphy

• Precise anatomical correction of perineal hernia is mandatory for successful outcome.
• Many techniques are available for correction of the defect.
  • Conventional method
    • The animal is restrained in ventral recumbency in an inclined position with the hind quarters elevated. The tail is lifted up and tied in front.
    • An incision is made over the swelling. The contents are reduced. The structures are identified and the correction is made in the following manner.
    • The medial cocygeus muscle is sutured to the external anal sphincter on the dorsal aspect. The sacro sciatic ligament is anchored to the external anal sphincter on the lateral aspect and the internal obturator muscle on the pelvic floor is sutured to the external anal sphincter on the ventral aspect.
  • Internal obturator flap
    • In this technique the internal obturator flap is elevated from the pelvic floor using a periosteal elevator and sutured to the medial coccygeus, levator ani and external anal sphincter.
    • The advantage of this technique is that it acts as a sling to suspend the rectum and does not cause undue tension on the external anal sphincter as in the conventional technique.
    • Recurrent perineal hernia can be corrected using techniques such as semitendinosus muscle and reinforcement with tensor fascia lata.