Pelvic Symphysiotomy in Cows: Indications, Instruments & Surgical Procedure in Veterinary Obstetrics

Pelvic symphysiotomy is a specialized surgical technique used in veterinary obstetrics to manage dystocia due to fetopelvic disproportion, particularly in heifers. This post outlines the indications, instruments and procedure.

Pelvic symphysiotomy is a surgical procedure used to enlarge the pelvic inlet by splitting the ischiopubic symphysis.

Indications

Pelvic symphysiotomy is indicated in cases of fetopelvic disproportion, particularly in heifers. In older animals, the procedure is less feasible due to ossification of the pelvic symphysis.

Instruments

• Scalpel
• Symphysiotomy chisel
• Hardwood bittern

Restraint

Epidural analgesia with 4–6 ml of 2% Lignocaine is used for the pelvic symphysiotomy procedure.

Procedure

After the vulva and the ventral perivulvar area have been scrubbed and disinfected, a metal urinary catheter is introduced into the urethra to monitor its location and to keep it out of the path of the chisel.

The entire symphysis is tested for ossification with a 22-gauge hypodermic needle, which is punched through the ventral vaginal wall. If no ossification is found, a 5 cm long midline skin incision is made 3–4 cm below the ventral commissure of the vulva.

The incision is made through the subcutaneous fascia to the posterior end of the pelvic symphysis.

The cutting end of the chisel is then placed through the incision to engage the symphysis.

While one hand holds the chisel firmly in line with the symphysis, the other hand is inserted into the vagina and used to check the progress of the chisel by feeling its upper guard.

An assistant begins driving the chisel with a batten while the operator controls and guides the instrument.

When the blade reaches the anterior part of the symphysis, care must be taken to avoid injury to the abdominal organs.

After completion of the cut, the chisel is pushed further by hand through the symphysis to ensure that it is completely severed.

The operator should also ensure that the bladder is not trapped in the symphysis, which closes immediately after the fetus is removed.

The skin incision is left unsutured to allow drainage. It is recommended to support the hindlegs to avoid abduction after the operation.