a. Direct Method. The direct method embraces two types of procedures:
operative (immediate) and postoperative (delayed).
(1)
Immediate or operative cholangiography.
(a) This procedure is carried out in the operating room. The surgeon
aspirates the bile in the ducts and injects a contrast medium such as Hypaque or
Hippuran into the duct.
(b) A mobile x-ray unit, a portable high-speed grid cassette, and an
adequate supply of loaded cassettes, are used. The cassette tray with handle is first
loaded with a cassette; then it is positioned under the patient before the surgery is
started.
(c) The cassette tray handle is graduated with a centimeter scale. A
scout film is made to check positioning and the handle is marked, this enables the
technician to reposition the cassette tray during surgery. All movement of the cassette
tray is done at the head end of the table. Since the operative site is sterile-draped when
the tube is moved into position, the x-ray specialist must ask the surgeon to point out
the exact site for directing the CR.
(d) It is necessary to use as short an exposure time as possible,
especially when other than spinal anesthesia is used. If spinal anesthesia is given, the
patient should be instructed to suspend respiration during the exposure of the film. If the
patient cannot respond, ask the anesthesiologist to suspend the patient's respirations
during the exposure.
(e) Since the exposure must be made at a critical time during injection
of the contrast medium, the specialist should ask the surgeon to give him a signal so
that he can expose the film at the proper time.
(f) Before exposing the film, the specialist should direct his attention to
the surgical site to make certain that none of the surgical instruments overlie or obscure
the area to be x-rayed. This is extremely important. Failure to observe this precaution
may necessitate re-exposure and delay the surgical procedure.
(g) Exposed films should be processed immediately for reading.
Additional films are made at the request of the surgeon.
(h) The entire procedure must be carried out under aseptic conditions.
Ensure that you pay attention to all sterile fields and patient drapes, taking care not to
contaminate those areas.
(i) A representative cholangiogram made during surgery is shown in
figure 2-23. A sketch to aid in positioning the patient is shown as figure 2-24.
MD0959
2-38
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