Minimally Invasive Surgery Techniques in Exotic Animals

Laparoscopic Salpingectomy and Vasectomy to Inhibit Fertility in Free-Ranging Nutrias (Myocastor coypus)

The nutria (Myocastor coypus), an invasive alien species, is widely spread in Europe. Pursuant to regulation (EU) no. 1143/2014, the nutria is subject to management programs to reduce its spread. Surgical fertility control is considered an acceptable method, particularly in urban circumstances, avoiding euthanasia. To maintain the hormonal patterns and the social and behavioral dynamics, surgical infertilization preserving the gonads (i.e., salpingectomy and vasectomy) is recommended. Mini-invasive surgery is an eligible choice when dealing with wildlife, allowing reduced captivation time. For these reasons, 77 free-ranging nutrias, captured in urban nuclei in Italy, underwent infertilization under general anesthesia; laparoscopic salpingectomy and vasectomy were performed on 32 animals and traditional surgery on the remainder, leaving the gonads in place. A three-port technique was used, with two paramedian trocars (5 mm) for the instruments and a median one for the telescope. Ablation was obtained through Onemytis® plasma device, allowing a rapid surgical time with no need to place visceral sutures; the skin was surgically closed. After recovery, the animals were released, and no overt complications were noted. No modification of the behavioral patterns was noted, and the population decreased during the following months.

Comparison of intra- and postoperative variables between laparoscopic and open ovariectomy in rabbits (Oryctolagus cuniculus)

OBJECTIVE

To compare intraoperative and short-term postoperative variables pertaining to laparoscopic ovariectomy (LapOVE) and open ovariectomy (OVE) in rabbits (Oryctolagus cuniculus).

ANIMALS

Twelve 4- to 5-month-old female New Zealand White rabbits.

PROCEDURES

Rabbits were randomly assigned to undergo LapOVE (n = 6) or OVE (6), with a vessel-sealing device used to seal and transect the ovarian pedicles. Laparoscopic ovariectomy was performed with a 3-port approach. Variables were measured during surgery (surgery and anesthesia times and incision lengths) and for up to 7 days after surgery (food consumption, feces production, body weight, vital parameters, blood glucose and cortisol concentrations, abdominal palpation findings, facial grimace scale scores, and ethograms).

RESULTS

Mean surgery (43.2 vs 21.7 minutes) and anesthesia (76.2 vs 48.8 minutes) times were longer and mean incision length was shorter (24.0 vs 41.5 mm) for LapOVE versus OVE. No significant differences in postoperative variables were identified between groups. During LapOVE, small intestinal perforation occurred in 1 rabbit, which was then euthanized. Postoperative complications for the remaining rabbits included superficial incisional dehiscence (LapOVE, 1/5; OVE, 2/6), subcutaneous emphysema (LapOVE, 1/5; OVE, 0/6), and seroma formation (LapOVE, 1/5; OVE, 0/6).

CONCLUSIONS AND CLINICAL RELEVANCE

Surgery time for LapOVE was twice that of OVE, and LapOVE resulted in unique complications in rabbits. No evidence of a reduction in pain or faster return to baseline physiologic status was found for LapOVE. Further evaluation of LapOVE in rabbits is warranted, with modification to techniques used in this study or a larger sample size.

The feasibility and effectiveness of thoracoscopic transdiaphragmatic approach for lung biopsy in rabbits. A randomized study

PURPOSE

To assess the feasibility of thoracoscopic transdiaphragmatic approach for biopsy of all lung lobes and to determine the optimal intercostal space (ICS) for biopsy of each lung lobe.

METHODS

Ten rabbits were positioned in dorsal recumbency. Total thoracoscopy lung biopsy was made combined transdiaphragmatic approach and right ICS approaches. A camera port was made in the transdiaphragmatic approach and the instrument port was made of ICS 7 and ICS 9. A pre tied loop ligature was placed to performed a caudal lung lobe biopsy and to simulate biopsies of the others lung lobes.

RESULTS

Biopsy of the cranial aspect of the right caudal lung lobe was performed at ICS 9. Simulated biopsy of the accessory lung lobe was performed at ICS 9. Simulated lung biopsy of the right cranial and middle lung lobes was performed at ICS 7. The caudal and dorsal aspect of the right caudal lung lobe was not visualized by telescope at transdiaphragmatic approach, and biopsy was not performed.

CONCLUSIONS

Thoracoscopic transdiaphragmatic approach for lung lobes biopsies was a feasible technique, except for the caudal aspect of the right caudal lung lobe. An ideal intercostal port for biopsy of each right lung lobe was determined.

Effects of intra-abdominal pressure on laparoscopic working space in domestic rabbits (Oryctolagus cuniculus)

OBJECTIVE

To assess the effects of 3 intra-abdominal pressures (IAPs) on pneumoperitoneal (laparoscopic working space) volume in domestic rabbits (Oryctolagus cuniculus).

ANIMALS

6 female New Zealand White rabbits.

PROCEDURES

A Latin-square design was used to randomly allocate sequences of 3 IAPs (4, 8, and 12 mm Hg) to each rabbit in a crossover study. Rabbits were anesthetized, subumbilical cannulae were placed, and CT scans were performed to obtain baseline measurements. Each IAP was achieved with CO₂ insufflation and maintained for ≥ 15 minutes; CT scans were performed with rabbits in dorsal, left lateral oblique, and right lateral oblique recumbency. The abdomen was desufflated for 5 minutes between treatments (the 3 IAPs). Pneumoperitoneal volumes were calculated from CT measurements with 3-D medical imaging software. Mixed linear regression models evaluated effects of IAP, rabbit position, and treatment order on working space volume.

RESULTS

Mean working space volume at an IAP of 8 mm Hg was significantly greater (a 19% increase) than that at 4 mm Hg, and was significantly greater (a 6.9% increase) at 12 mm Hg than that at 8 mm Hg. Treatment order, but not rabbit position, also had a significant effect on working space. Minor adverse effects reported in other species were observed in some rabbits.

CONCLUSIONS AND CLINICAL RELEVANCE

A nonlinear increase in abdominal working space was observed with increasing IAP. Depending on the type of procedure and visual access requirements, IAPs > 8 mm Hg may not provide a clinically important benefit for laparoscopy in rabbits.