Paramedian Abdominal Approach: Technique

Objectives of the Presentation

Present an alternate approach for limited access to the caudal abdomen in male dogs.

General Key Points:

Technique Advantages
Easy, quick method to access the caudal abdomen in male dogs. Allows continuation of exploration outside abdominal cavity along inguinal region to scrotum, if needed.

Technique Limitations
Only allows limited access to caudal abdomen. May cause more hemorrhage in abdominal wall compared to midline approach.

Key point: Surgeon must be certain that further exploration of abdomen will not be required before attempting this approach. Further access to abdominal cavity from the paramedian approach will cause unnecessary tissue dissection and bleeding.

Key Anatomy Points: Between the umbilicus and the pubis, the external rectus sheath is comprised of fused fascia of the external and internal abdominal oblique muscles, and the transverses abdominis muscle. On the lateral half of the external rectus fascia there are 2 separate fascial sheets (the fused fascial sheets of the abdominal oblique muscles, and the fascial sheet of the transversus abdominis muscle. In this area, there is no internal rectus fascia deep to the rectus abdominus muscle but there is a thin layer of peritoneum present. The caudal superficial epigastric vessel runs medial to the nipples as it runs forward to supply the prepuce, superficial inguinal lymph node, and mammary skin. The deep epigastric vessel runs about 1-2 cm lateral to the linea alba just deep to the rectus abdominus muscle. Smaller branches of this vessel course both lateral and more superficial in the muscle.

Technique

Step 1
With the dog positioned in dorsal recumbency, place a towel clamp on the prepuce (if a urethral catheter is not expected to be used in the procedure) and clamp it to the skin on one side of the body (the side opposite the side of your intended abdominal approach). If you expect that you will need access to the urethra, for example, to flush urinary calculi from the urethra, thoroughly irrigate the prepuce with antiseptic solution and position the prepuce within your sterile field.

Step 2
Create a skin incision about 1 cm parallel and lateral to the nipples from the level of the cranial aspect of the prepuce to about 3-4 cm cranial to the pubic bone (palpate this landmark under the skin). Avoid the caudal superficial epigastric vessels, which run longitudinal and parallel to nipples. [...]