Standing Flank Laparoscopy

The general approach used for standing laparoscopy begins with fasting the horse for 24 hours to decrease the volume of the intestinal contents, and consequently improve visualization. The use of nonsteroidal antiinflammatory drugs, and antibiotics is variable. The left flank in all cases, and the right flank in some cases is prepared for aseptic surgery. Sedation is surgeons preference with some using intravenous sedation along with a caudal epidural while others use only a detomidine caudal epidural.^4-6 The skin and musculature of the flank is infiltrated with 40 to 60 ml of local anesthetic (2 % lidocaine or 2 % mepivacaine) in an inverted “L” pattern. Caudal epidural injections⁷ are performed with either a combination of 2% mepivacaine and xylazine (0.18 mg/Kg), xylazine (0.18 mg/Kg qs to 10–15 ml with 0.9% sodium chloride), or detomidine (40–60 mg/Kg qs to 10 ml with 0.9% sodium chloride) to desensitize the caudal abdomen. The horse is draped to allow access to one or both flanks as needed. The author prefers to insert a trochar catheter (Medicut Argyle trochar catheter, Sherwood Medical, St. Louis, MO) into the peritoneal space through a small stab incision in the skin in the middle of the flank (at the ventral most level of the tuber coxae, midway between the last rib and the tuber coxae) for carbon dioxide insufflation before trochar/cannula placement. Presence of the tip of the catheter in the peritoneal space is confirmed with negative pressure and the sound of air being drawn into the abdomen. Once the abdomen is distended, one or more trochar/cannulas are placed through the body wall. A skin incision similar in size to the cannula is made and the trochar/cannula is placed into the abdomen with a slow, but constant, twisting motion. The telescope is placed through a cannula and connected to the light source and video camera. As many cannulas as necessary, limited of course to the size of the surgical site, can be placed. Cannulas can be placed in the 17th intercostal space. At the end of the procedure, the abdomen is desufflated (passively, or actively with suction), the cannulas removed, and small incisions are closed with simple interrupted skin sutures, while larger incisions are closed with a simple continuous pattern in the external abdominal oblique muscle, and a simple interrupted pattern in the skin.

Ventral Midline Laparoscopy

Preoperative preparation is similar to that for the standing horse. The horse is anesthetized, placed in dorsal recumbency, and the ventral abdomen is aseptically prepared for surgery. The exact location of the draping depends upon the area of interest, but usually includes the umbilicus and the body wall out to the folds of the flank, and either to the inguinal region or the xiphoid. No matter the area of interest, a veress needle or teat cannula is inserted into the peritoneal space through a small stab incision at the umbilicus, and connected to a carbon dioxide insufflator to distend the abdomen to 15 mmHg. Once the abdomen is distended, the veress needle or teat cannula is removed, the skin incision increased to the size of the telescope cannula, and a trochar/cannula placed through the body wall. The animal can then be tilted so that the rear quarters are elevated (Trendelenberg position) to ease exploration and surgical manipulation in the caudal abdomen, or tilted so that the fore quarters are elevated to ease exploration and surgical manipulation in the cranial abdomen. In either case, the horse may need to be tied to the table to reduce movement of the patient. Other cannulas may be placed under direct visualization. Some surgeons prefer to preplace a spinal needle to determine the exact entry point of the additional cannulas.