Biomedical Engineering Reference
In-Depth Information
appropriate sutures and closing technique, and minimization
of dead space and duration of surgery. Conscientious
researchers should consult and/or collaborate with an expe-
rienced veterinarian (
National Research Council, 2011b
)or
possibly with a physician specialist on select procedures
outside veterinary expertise. The American Veterinary
Medical Association (AVMA) policy on “Surgical Proce-
dures by Non-Veterinary Students” does not advocate
instruction of nonveterinary students in surgical procedures
(
American Veterinary Medical Association, 2011
). If such
instruction is provided, surgery should only be performed
under direct veterinary supervision and with prior approval of
the appropriate IACUC. Recently, however, the AVMA
added an exemption for surgery performed for research
purposes (
Hampshire and Gonder 2007a; American Veteri-
nary Medical Association, 2011
). Although approval of
research surgeries is the responsibility of the IACUC, the
veterinarian is the primary advisor to the IACUC in these
matters. After approval of initial surgeries by the IACUC,
researchers who lack clinical training or experience may
resist reasonable suggestions such as giving the animal more
time to recuperate, performing an explantation surgery, or
even euthanasia as an alternative to a desperate attempt to
salvage a project. Determination of the best course of action
regarding repair surgeries, salvage surgeries, or repeated
surgeries often relies on the clinical
avoid skin nicks. Hair plucking, depilators (always to be
washed off with soap and water), or small scissors may
be used as an alternative in areas inaccessible for
clipping.
Positioning
Optimal positioning is generally determined by the area of
focus of the surgeon and the physiological function and
comfort of the patient. Limb flexion may compromise
peripheral circulation and contribute to the formation of
intravascular thrombosis, local ischemia, or postoperative
edema. If special positioning, such as elevated limb or head
using stereotactic apparatus, is needed the use of extra
cushioning is advised. Pieces of sponge, surgical towels, or
folded pads may be placed in areas where the secondary
decubitus ulcer could form (e.g. knees, elbows).
Surgeon's Prep
It is essential for the surgical team to adhere to established
aseptic practices, especially since nonhuman primates may
undergo lengthy procedures performed by researchers with
a wide range of surgical skills. Surgeons must wear caps,
beard covers (if indicated), masks (making a tight seal
over the bridge of the nose with the “crimp strip”), sterile
gloves, and sterile gowns donned in aseptic fashion and
worn over laundered scrub uniforms. Scrub brushes/
sponges soaked with antiseptics such as 8% povidone-
iodine (minimum available iodine 0.5%) w/w, alcohol/
detergent (7% isopropyl alcohol), or chlorhexidine
gluconate (4%) are commercially available. The manu-
facturer's recommended 3-minute scrub/rinse/repeat
should cover all four surfaces of each finger, thumb, hand,
and forearm to just below the elbow joint. Newer formu-
lations of single application materials (1% chlorhexidine
gluconate solution and ethyl alcohol 61% w/w) designed
to be scrubless, waterless, and fast acting may be used
while performing successive surgical procedures (after
doing a full scrub for the first procedure). Closed gloving
is preferred to open gloving in aseptic surgeries (
Lang and
Mancuso, 1982
), and the “prayer position” recommended
when surgeons are not operating. Veterinary staff should
be vigilant about accidental contamination by researchers
and require re-gloving even if it happens repeatedly.
Regularly offered surgery preparation training sessions for
new investigative staffs to review the above processes are
highly recommended.
judgment of the
veterinarian.
Asepsis Versus Antisepsis
The following concepts are commonly used:
Clean surgery (alimentary, respiratory, and urinary
tracts not entered, e.g. craniotomy).
l
Clean-contaminated surgery (respiratory and urinary
tracts entered, no significant spillage of contaminated
contents, e.g. tracheostomy, pulmonary lobectomy).
l
Contaminated surgery (gross spillage of contaminated
body contents or acute inflammation, e.g. abdominal
injury with intestinal laceration).
l
Dirty surgery (purulent exudate present and micro-
organismal content
l
10
5
bacteria/g of tissue (
Turner and
McIlwraith, 1982a; Dunning, 2003
), e.g. craniotomy/
durotomy to drain contents of a subdural, cortical abscess
or repair of head cap devices in the face of clearly
infected scalp-device interfaces).
>
Antibiotics should never be a substitute for a sound aseptic
approach.
Surgical Field Prep
The surgical site's scrub should follow the standard three
cycles of scrub and rinse using acceptable compounds
such as tamed iodine or chlorhexidine scrub, rinsed with
70% ethanol, or sterile water, and followed by an appli-
cation of tamed iodine solution allowed to dry. A circular
Preoperative Considerations
Hair Removal
Hair removal is critical for postoperative healing. Electric
clippers, rather than blades or razors, should be used to
