Page 314 - Clinical Manual of Small Animal Endosurgery

302 Clinical Manual of Small Animal Endosurgery

performed in young prepuberal rabbits (less than 6 months of age). The
author has safely performed laparoscopic ovariohysterectomies in giant-
breed rabbits as young as 12 weeks old.
Laparoscopy has been clearly demonstrated to result in lower post-
operative abdominal adhesion formation than open surgery in rabbits
(Luciano et al., 1989; Jorgenson et al., 1995; Tittel et al., 2008), and
also in lower postoperative mortality rates than laparotomy in rabbits
with peritonitis (Chatzimavroudis et al., 2009).
A disadvantage of laparoscopy is that unrecognised bowel injuries in
rabbits, typically incurred during access, result in delayed clinical mani-
festations compared to open abdominal surgery. This appears due to the
fact that less of an inflammatory response occurs with the minimally
invasive nature of laparoscopy (Aldana et al., 2003; El-Hakim et al.,
2004, 2005). In contrast to rabbits with intestinal leakage deteriorating
within 12–24 h of open surgery, clinical impairment may be delayed for
2–3 days in rabbits undergoing laparoscopy. Laparoscopic lavage also
appears to be less effective in removing abdominal contamination, and
has a higher associated risk of postoperative adhesion formation than in
humans (Roberts et al., 2002). This is likely due to the fact that the small
operative space makes truly effective lavage difficult. It is hence essential
that the abdomen is always carefully examined immediately after entry
of the laparoscope for any signs of bowel trauma or intestinal leakage
before proceeding further.
Care must be taken with electrosurgery in rabbits, as inadvertent
peritoneal cautery or excessive charring will result in adhesion formation
(Balbinotto et al., 2010). The thick fur of rabbits, combined with their
low body weight, may also result in poor ground-plate contact when
using monopolar electrosurgery and result in burns. Radiosurgical fre-
quencies carry a lower risk. Alternatively the area to lie against the
contact plate may be clipped and wet swabs used to improve contact.

Thoracoscopy
While thoracoscopy is certainly possible in small pet mammals, size
constraints limit its applications, as well as making inadvertent pulmo-
nary trauma a much higher risk than in larger mammals. It can in fact
be very difficult to always enter instruments through ports under safe
visual control (Fig. 10.22). Small rib spaces preclude the use of endo-
scopic staplers, which are 12 mm in diameter, in even the largest rabbits.
Lung biopsies require the use of commercially available pre-tied loop
ligatures, or the surgeon employing a self-tied extracorporeal knot, such
as the Meltzer knot (see Chapter 6). An advantage of self-tied knots is
that they may be applied through 3 mm ports, unlike commercially avail-
able knots which require 5 mm ports. In some patients even 3 mm instru-
ments are too large. The extremely limited operating space remains the
main constraint, although more technically difficult procedures have
been performed, such as thymic cyst removal (Fig. 10.23).