Page 35 - Clinical Manual of Small Animal Endosurgery

Rigid Endoscopy 23

Fig. 1.21 Sterile trolley laid out in an orderly fashion for endosurgery
(e.g. laparoscopic ovariectomy). Photograph courtesy of Mr P.J. Lhermette.

Operating-room equipment
The variety and length of instruments used in this type of surgery (espe-
cially laparoscopy and thoracoscopy) requires the provision of one or
more large instrument trolleys to allow the instruments to be laid out in
an orderly and secure fashion (Fig. 1.21). During laparoscopy and tho-
racoscopy the use of gravitational forces to displace other organs is a
very effective means of retraction to increase visualisation of the opera-
tive site. A surgical table that allows the patient to be positioned with
the head down or up (the Trendelenburg and reverse Trendelenburg
positions respectively), as well as to be rotated from side to side, is
therefore of great help in improving exposure of the area of interest. The
height of the table should also be adjustable. Table height is generally
lower during endoscopic procedures than conventional procedures. This
is because of the greater length of the instruments and because the sur-
geons are looking across the table to the monitor rather than down onto
the patient.
Nearly all rigid endoscopic procedures require the patient to be under
general anaesthesia. To improve a patient’s safety this requires a dedi-
cated member of the team and appropriate monitoring should be avail-
able. Furthermore, some endoscopic procedures such as laparoscopy and
thoracoscopy require special anaesthetic considerations. The cardiovas-
cular status of the animal must be closely evaluated in laparoscopy
because of the induction of pneumoperitoneum. Carbon dioxide diffuses
across the peritoneum, causing a significant increase in arterial blood
carbon dioxide levels (Duke et al., 1996). There is often a corresponding
decrease in oxygenation, even in patients receiving mechanical ven-
tilation. Insufflation of the abdomen also increases intra-abdominal