Exploratory Laparotomy in the Dog & Cat

Step 1.

Generously clip and prepare the surgical site, extending cranially to the xiphoid, caudally to the pubis, and over 5 to 10 cm from the ventral midline on either side. Express the bladder through the abdominal wall. 

Author Insight:

Midline laparotomy incision should extend from xiphoid to pubis.

Step 2.

Inject preincisional block (2 mg/kg bupivacaine) along the ventral midline from the beginning to the end of the proposed incision in a fan-like fashion to infiltrate subcutaneous and muscular tissues. This technique provides postoperative analgesia for at least 24 hours.^3,4 

Step 3.

Use a 4-corner draping technique: in male dogs, grasp the prepuce with towel forceps and position laterally to the midline to avoid urine spillage into the surgical site; penis and prepuce can be covered by 1 of the lateral drapes. Make a parapreputial skin incision, dividing the preputial muscles and sealing external pudendal vessels with elecrocautery following the incision to allow reflection of the prepuce and penis laterally to visualize the linea alba. In female dogs and all cats, extend the ventral midline incision from xiphoid to pubis.

Step 4.

After skin incision, seal subcutaneous vessels via elecrocautery and undermine subcutaneous tissues from attachment to the rectus sheath 1 cm laterally to visualize the linea alba. Avoid excessive undermining to prevent vascular compromise of the fascia and dead space creation and subsequent seroma formation.

Step 5.

Make a stab incision to the linea alba with a scalpel and insert a finger into the incision to ensure entry to the abdominal cavity and to confirm that there are no adhesions between the abdominal wall and intra-abdominal organs. A stab incision and letting air into the abdominal cavity also allows the abdominal organs to “fall” dorsally, away from the ventral aspect of the abdominal wall, making the subsequent extension of the midline incision safer.

Step 6.

Insert thumb forceps with the tips placed caudally to lift upward on the linea alba and make a cranial to caudal incision. Extend the incision cranially by directing thumb forceps with tips placed cranially. 

Step 7A.

An alternative technique to enter the abdominal cavity is to lift the linea alba with thumb forceps and make a stab incision with the cutting edge of the scalpel blade pointing upward.

Step 7B.

Use Mayo scissors to extend the incision.

Step 8.

When treating dogs, excise the falciform ligament with elecrocautery or by placing a ligature at its base to improve exposure to the cranial abdomen. 

Step 9.

After the abdomen is entered, protect wound edges with moistened laparotomy pads and place Balfour retractors.

Step 10B.

Gently lift the colon and mesocolon toward the right side of the animal to expose abdominal organs of the left paravertebral fossa.

Step 11A.

Following abdominal exploration, lavage the abdominal cavity using large volumes of warm normal saline solution, which aids in removal of contaminants and patient warming (A, B).^2,5 Completely remove lavage fluid by suction before closing the abdomen to avoid compromise of defense mechanisms.²

Step 11B.

Following abdominal exploration, lavage the abdominal cavity using large volumes of warm normal saline solution, which aids in removal of contaminants and patient warming (A, B).^2,5 Completely remove lavage fluid by suction before closing the abdomen to avoid compromise of defense mechanisms.²

Step 12A.

The midline laparotomy incision is closed in 3 layers. The abdominal wall is closed using the external leaf of the rectus abdominis muscle sheath in a simple continuous or simple interrupted suture pattern. Most surgeons favor a continuous polydioxanone or polyglyconate suture pattern, which provides a quick and secure closure. Sutures should be placed 5–10 mm from the incision edge and spaced 5–10 mm apart, depending on the size of the animal.^6,7 

Step 12B.

Suture size depends on the animal’s weight (animals <5 kg: 3/0; 5–20 kg: 2/0; 20–40 kg: 0; and >45 kg: 1).

Author Insight:

Closure of the linea alba must include the external leaf of the rectus sheath. 

Step 13A.

Place 6 throws at the beginning and 7 at the end of the continuous pattern.^8,9

Step 13B.

Sutures should be placed tightly enough, depending on the suture material used, to get the incision edges into apposition.

Step 14A.

For the second layer, subcutaneous closure is most commonly accomplished in a simple continuous pattern using 3/0 synthetic absorbable monofilament suture to eliminate dead space and decrease tension in the incision, allowing skin edges to be placed in close apposition.

Step 14B.

In male dogs, preputial muscle should be apposed separately with a couple of simple interrupted sutures to reposition the penis normally. 

Author Insight:

Sutures should not be placed too tightly as this can cause ischemic necrosis of the incision edges; however, they must be tight enough to achieve adequate apposition of the incision edges. 

Step 15.

Close skin using a simple continuous (A), Ford interlocking (B), or intradermal pattern with buried knots (C), or use staples (D).