Chapter 68 Laparoscopic Surgery in the Elephant and Rhinoceros

Traditional abdominal surgery in the elephant and rhinoceros has rarely been performed and, in those cases in which it has, success has been limited.^1,⁴ Emergency cesarean sections in elephants have been attempted and have proved fatal for both the calf and mother. Successful castration of bull elephants has been described.^2,^3,¹² In these reports, young animals were castrated in a single procedure, whereas adults required multiple procedures. These elephant castration procedures were difficult and it was not uncommon for incisions to break down and heal by second intention. An abdominal exploratory and ovariectomy has been reported in an Indian one-horned rhinoceros, but the animal died 48 hours after the surgery.¹¹

Abdominal surgery in the elephant and rhinoceros is difficult for several reasons, the first being the animal’s overall size and how it affects the surgeon’s ability to reach and manipulate organs. Second, there is considerable thickness to the skin and body wall, which requires larger incisions and an inordinate amount of time for closure. Surgical sites may also be predisposed to dehisce and break down.^2,¹² An additional complicating anatomic variation in elephants is their peritoneum. Unlike most other mammal species, the peritoneum is covered by a fibroelastic layer and is itself redundant and only loosely attached to the body wall.⁵ For this reason, entering the peritoneal cavity of elephants, even after making an incision through the dermis and associated muscle layers, may be very challenging. Finding a route to and through the peritoneum is much more of an issue when animals are in lateral recumbency (versus standing), when there is less tension on the peritoneum. Rigid laparoscopy, or minimally invasive surgery (MIS), offers a variety of advantages over traditional surgical procedures. In humans and animals, MIS has been shown to be less painful, requires less healing time, allows faster return to normal function, and has less chance for infection.¹⁹ For the elephant and rhinoceros, MIS has these advantages and thus makes abdominal surgery a realistic and much less risky procedure. Laparoscopic abdominal surgeries have been successfully performed in the African elephant, white rhinoceros, and black rhinoceros.^6,^13,¹⁵^–¹⁷ Procedures have included abdominal exploration with diagnostic sampling and a variety of reproductive surgical techniques.

Laparoscopy in the Elephant

Animal Positioning

Abdominal laparoscopic surgery in elephants is best accomplished in a standing position, either with the animal sedated and in a restraint device or under general anesthesia, with the animal in a standing position while being suspended from a crane truck.^6,¹⁵^–¹⁷ Using MIS and maintaining the elephant in a standing position allows for small incisions, rapid access to the abdominal cavity, and excellent overall surgical success.⁷ In captive situations, in which sedation may be used along with some degree of manual restraint, abdominal laparoscopic surgery may be readily accomplished. We have successfully used butorphenol and detomidine in conjunction with local analgesic nerve blocks with the elephant in a restraint chute (Fig. 68-1). The patient is sedated to the level at which it cannot lift its trunk and maintains a wide stance on all four legs, but is not likely to lie down. Once sedated, a regional analgesic block is accomplished using a 5-inch, 18-gauge spinal needle. In elephants, an elevated platform is used to place the surgeons at the level of the paralumbar fossa. This standing sedation approach has been used for abdominal exploratory and reproductive procedures in both adult elephants and rhinoceroses.