These two different approaches to the caudal of the male dog are worth being discussed. The most common indications for these approaches are for performing a cystotomy in a male dog and dealing with a retained intra-abdominal testicle(s). The textbooks describe the paramedian approach, which I have used many times; but I prefer the parapreputial approach much more.
The paramedian approach starts with a skin incision lateral to the prepuce and lateral to the Caudal Superficial Epigastric vein (thus lateral to the mammary chain). The SQ tissues are cleared (they are sparse at this level), and an incision is then made in the abdominal wall through the external and internal abdominal obliques (the idea being that you are lateral to the rectus abdominis).
The parapreputial approach starts with a skin incision lateral to the prepuce and medial to the Caudal Superficial Epigastric vein. The SQ tissues are cleared (they are thick here), and the abdomen is entered through the Linea Alba.
Both approaches are good and neither is perfect, so here are their pros and cons, and you can decide which you think might be best in your hands.
Paramedian:
Pros – Very little SQ tissues to incise through and close. If searching for a cryptorchid testicle, this incision places you over the path of the descending testicle.
Cons – Muscular bleeders can be more of an issue at surgery and cause more of a hematoma/swelling post-op. This is not a grid approach; the incision in the abdominal wall goes across the muscle fibers, not along them, therefore closure is less accurate and return to full function can take longer (although clinically we would not likely really notice this last point). Entering the abdomen from this approach is much less familiar and therefore can add difficulty. This incision cannot be extended much at surgery, thus no room for error or further exploration if necessary. This approach is not useful in the bilateral cryptorchid patient.
Parapreputial:
Pros – The approach into the abdomen is very familiar, and the incision can easily be extended if necessary. Minimal bleeding with a Linea Alba approach means less swelling. Perfect approach for a bilateral cryptorchid.
Cons – Requires pushing the prepuce/penis to one side. The SQ tissues here are thick and therefore require a careful approach and closure to prevent seroma formation (I always close this SQ in 2 layers). This approach is not well described in the textbooks, so watch if you are not familiar with it.
