Page 290 - Clinical Manual of Small Animal Endosurgery

278 Clinical Manual of Small Animal Endosurgery

If using an open-access approach to placement of the primary optical
trocar in small mammals, a flexible, low-profile ring retractor such as
the Lonestar retractor (ARK Surgical UK) can be extremely useful, espe-
cially in obese rabbits. It can also aid laparoscopy-assisted procedures,
such as laparoscopy-assisted gastrotomy for foreign bodies in ferrets
or iguanas, or laparoscopy-assisted cystotomy for urolithiasis in male
rabbits, by replacing the need for stay sutures, with the time-saving use
of fine blunt-ended elastic stays. This reduces the risk of any abdominal
or coelomic contamination from an opened viscus.

Birds

Avian endoscopy and coelioscopy has been performed since the 1970s,
originally for sexing in species without obvious sexual dimorphism (Bush
et al., 1978; Harrison, 1978). Avian endoscopy is arguably the most well
established of all endoscopy techniques in exotic pet animals. This is
perhaps not necessarily due to its ease, as these are small patients, with
a limited operating space, and until fairly recently there was a limited
range of suitable small instruments for multiple puncture techniques. In
fact, it is almost certainly due to the fact that the alternative, open coe-
lomic surgery, is a much poorer option, with a notably higher morbidity
and mortality, as well as severe limitations in access and visualisation.
Careful handling of the endoscope and support of the camera, light
cable and endoscope eyepiece region are needed to prevent inadvertent
injury to delicate avian structures during endoscopy (Divers, 2011). It is
highly recommended that practitioners practice on avian cadavers of
different species, to familiarise themselves with normal avian anatomy,
species differences and their appearance during endoscopy.
The so-called universal 2.7 mm-diameter, 30° viewing angle, 18 cm
endoscope and associated operating sheath truly justifies its name in pet
avian endoscopy, and is well suited to psittacines and raptors that make
up a majority of avian pet patients. In larger avian patients such as large
raptors, a 4 mm endoscope is advantageous, being less fragile and yield-
ing enhanced visualisation and illumination. A 1.9 mm endoscope is
useful for tracheoscopy, and can be used in small patients, but is fragile
and easily damaged. A 30° endoscope is extremely useful, if not essential,
for maximising visualisation in the small coelomic space of most birds.
Avian patients share the fortunate factor for the endoscopist of having
their viscera suspended within the air sacs of the coelom, making insuf-
flation unnecessary. Carbon dioxide insufflation would actually kill the
patient through asphyxia. Anaesthesia requirements are the same for any
surgical intervention, and while anaesthetic gases escape from any coe-
lomic wounds, this is negligible in coelomic endoscopy and can generally
be ignored. While brief procedures (less than 20 min total anaesthesia)
are possible under maintenance with a face mask, it is advisable, and
certainly necessary in longer procedures, to maintain anaesthesia via