Avian GI and reproductive surgery (Proceedings)
A simple ventral midline celiotomy provides limited exposure to most abdominal organs in birds. The liver, pancreas and intestines are accessible through this approach. The hepatoperitoneal cavity is entered, but this cavity does not communicate with the air sacs located lateral to it on each side. Ascites is characterized by accumulation of fluid in this cavity. The duodenum and pancreas are immediately under the body wall and it is easy to inadvertently incise these structures. If the liver is of a normal size, it is usually under the sternum making it inaccessible. Coelomitis may cause fluid to accumulate in the hepatoperitoneal cavity. Fluid can be drained and irrigation of the hepatoperitoneal cavity can be safely performed as long as the air sacs are intact.
Exposure using a ventral midline approach can be improved by creating a flap extending along one side of the caudal border of the sternum leaving 2-3 mm of muscle into suture to. A Y shaped incision can be made creating bilateral flaps. Flap approaches often provide the best exposure to mid-abdominal masses, uterine masses, and generalized abdominal disease such as yolk coelomitis. The approach should be limited to the minimum needed to accomplish the task to minimize tissue trauma and disruption of air sacs. It may be difficult to maintain anesthesia with large abdominal approaches that disrupt air sacs. Closing the incision or covering the opening with saline moistened sponges for several breaths along with increasing the percent of anesthetic gas will often help with maintenance of anesthesia.A transverse abdominal approach provides exposure to a large portion of the abdomen. With the bird in dorsal recumbency a transverse incision is made midway between the vent and the caudal extent of the sternum. The duodenal loop and pancreas lie immediately under the body wal and the ventriculus, pancreas and small intestine are most accessible. If there is hepatomegaly, the caudal extent of the liver may also be accessible. The viscera may be reflected to expose the middle and caudal divisions of the kidneys, the cranial cloaca, and the lower reproductive tract. The body wall incision is closed in a simple continuous pattern and the skin in a Ford interlocking pattern.
A left lateral approach provides good exposure to most of the abdominal organs. The pancreas and structures on the right side are not very accessible through this approach. The bird is positioned in right lateral recumbency with the left leg retracted caudally. The skin incision is made from the middle of the pubis to the sixth rib dorsal to the uncinate process. After the skin is incised, the left leg can be retracted farther caudally to improve exposure. Branches of the femoral artery and vein are located within the body wall coursing toward midline from the area of the coxofemoral joint. These vessels must be coagulated or ligated before the abdominal musculature is incised. An incision is made through the mid-lateral body wall from the level of the pubic bone to the last rib. To gain exposure to the gonad and proventriculus, the last two ribs may need to be transected. The intercostal vessels are located just cranial to each rib. They are coagulated with bipolar forceps or hemostatic clips then the ribs are transected just dorsal to the angle of the sternal and vertebral portions. Avoid the lung which may extend as far caudal as the 7th rib. A retractor, such as a Heiss retractor, is placed between the cut ends of the ribs and used to spread the ribs providing exposure to the more cranial abdominal organs. Closure involves apposition of the abdominal and intercostal muscles. No effort is made to unite the cut ends of the ribs. Skin is closed in a Ford interlocking pattern. This approach offers exposure to the male or female reproductive tract, the ventriculus, the proventriculus, the spleen, the left lung, the left kidney and some of the intestines.