Page 250 - Manual of Equine Field Surgery

CHAPTER 44

Inguinal Herniorrhaphy

David A. Wilson

INDICATIONS . ANATOMY

Repair of congenital inguinal hernias is indicated The primary structures involved in congenital

for hernias that have not resolved by 3 to 6 months inguinal hernia repair are the superficial and deep

of age, for hernias that are gradually increasing in inguinal rings, the inguinal canal, the vaginal

size, or in cases in which owners request elective tunic and vaginal ring, the testicles, and the in-

repair.':" Foals with large hernias that have rup- testine within the hernial sac. The superficial

tured into the subcutaneous space or exhibit inguinal ring is formed by a slit in the aponeuro-

clinical signs of abdominal pain should not be sis of the external abdominal oblique. Its lateral

repaired in the field because of the difficulty in border continues as the femoral fascia, which is

reducing these hernias and the potential need for the medial fascia of the thigh. The deep inguinal

abdominal exploration. ring is formed by the internal abdominal oblique

muscle and arcus inguinalis (inguinal ligament).

EQUIPMENT The inguinal canal is a potential space between the

deep and superficial inguinal rings. The vaginal

tunic is an evagination of peritoneum that encases
No special equipment is required.
the testicle and sperrnatic cord. The vaginal ring,

a transition between the peritoneum and the

PREPARATION AND POSITIONING vaginal tunic, is a thickened ring that plays the role

of a limiting barrier against indirect herniation.

The horse is placed under general anesthesia and

positioned in dorsal recumbency. Preoperative

administration of antibiotics ( e.g., penicillin and PROCEDURE

gentamicin) and nonsteroidal antiinflammatory

agents are recommended. The caudoventral ab- Congenital inguinal hernias in the foal are gener-

domen is clipped and prepared for aseptic ally classified as indirect inguinal hernias in that

surgery, with care taken to not damage or irritate the intestines pass through an intact vaginal ring •

the sensitive inguinal skin. Aggressive scrubbing and are usually contained within the vaginal canal

and the use of alcohol should be avoided. Sterile and cavity ( the virtual space between the parietal

saline should be used to ensure complete removal and visceral layers of the vaginal tunic) (Figure

of any surgical soap. If there is any concern that 44-1). The approach is directly over the affected

the reduction may be prolonged, the bladder inguinal canal. A 10-cm incision is made centered

should be catheterized to minimize urine conta- over the superficial inguinal ring, starting at its

mination of the surgery site. cranial margin and extending caudal to the

246