How do you perform surgery on a rat? - briefly
First, induce anesthesia with isoflurane or an injectable cocktail, shave and disinfect the surgical area, and operate under a microscope using sterile microsurgical instruments. Then, make a precise incision, perform the required manipulation, close the wound with sutures or tissue adhesive, and administer postoperative analgesia.
How do you perform surgery on a rat? - in detail
Performing a surgical intervention on a laboratory rat requires strict adherence to aseptic techniques, precise anesthesia management, and careful postoperative monitoring.
Begin with animal selection and health assessment. Verify weight (typically 200–300 g), absence of overt disease, and appropriate acclimation. Record identification details and baseline parameters such as temperature and heart rate.
Pre‑operative preparation
- Fast the animal for 2–4 hours if the procedure involves the gastrointestinal tract; otherwise, maintain normal feeding.
- Shave the intended surgical site with electric clippers, then apply a depilatory cream if necessary.
- Disinfect the skin using alternating swabs of 70 % ethanol and povidone‑iodine, allowing each to dry before the next application.
Anesthesia
- Induce with inhalational agents (isoflurane 3–5 % in oxygen) via a calibrated vaporizer and a nose cone; maintain at 1.5–2 % for the duration of the operation.
- Confirm depth of anesthesia by the loss of pedal reflex and absence of spontaneous movement.
- Continuously monitor respiratory rate, oxygen saturation (if available), and core temperature; use a rectal probe and a warming pad to prevent hypothermia.
Instrumentation
- Sterile scalpel with a #10 blade, microsurgical scissors, fine forceps (Dumont #5), and needle holders.
- Suture material: 5‑0 or 6‑0 monofilament nylon or absorbable polyglactin, depending on tissue type.
- Optional: operating microscope or magnifying loupes for delicate structures.
Surgical steps (example: abdominal midline laparotomy)
- Position the rat in dorsal recumbency; secure limbs with tape to prevent movement.
- Make a midline skin incision of 1–2 cm using a scalpel; incise the underlying fascia with the same blade.
- Retract the incision edges with sterile stay sutures or small forceps to expose the peritoneal cavity.
- Perform the intended manipulation (organ exposure, tissue excision, grafting, etc.) using microsurgical techniques; control bleeding with bipolar cautery or micro‑clips as needed.
- Close the peritoneum and fascia with a continuous 5‑0 absorbable suture, ensuring a watertight seal.
- Approximate the skin with interrupted 6‑0 nylon sutures or a tissue adhesive; limit the number of knots to avoid excess foreign material.
Post‑operative care
- Allow the animal to recover in a warmed chamber; monitor until the righting reflex returns.
- Administer analgesia (e.g., buprenorphine 0.05 mg/kg subcutaneously every 8–12 hours for 48 hours) to mitigate pain.
- Provide supplemental fluids (0.5 ml warm saline subcutaneously) if needed.
- Inspect the incision daily for signs of infection, dehiscence, or swelling; remove skin sutures after 7–10 days.
Ethical compliance
- Obtain approval from the institutional animal care and use committee (IACUC) before any procedure.
- Follow the “3Rs” principle: replace with non‑animal alternatives when possible, reduce the number of subjects, and refine techniques to minimize distress.
Adhering to these protocols ensures reproducible outcomes, maintains animal welfare, and satisfies regulatory standards for rodent surgical research.