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Figure 8: (a) Trachea wrapped within lateral thoracic artery flap,
tunneled to cervical incision. The pedicle (green arrow) is oriented
perpendicular to the longitudinal tracheal axis. The flap is fixed loosely
to the local subcutaneous tissue to prevent dislocation; (b) lateral neck
incision with tunneled construct (left) and lateral thoraco-abdominal
incision (right), the flap donor site
threatening apnea in rabbits. Therefore, proper induction
[19]
is carried out with the use of xylazine 6 mg/kg and ketamine
40 mg/kg intramuscularly, each injected into 1 gluteal region. Figure 9. Orthotopic inset of trachea prelaminated within the left
The primary function of xylazine is sedation, while ketamine lateral thoracic artery flap (between green arrows)
induces dissociative anesthesia. Analgesia is achieved by
administering buprenorphine 0.05 mg/kg subcutaneously in with the rabbit in dorsal decubitus without the need
the gluteal region. Additional doses are administered every to change position. After achieving proper sedation,
8 to 10 h, up to 72 h or as needed. Once proper induction the rabbit is shaved and the skin is disinfected with an
is achieved, maintenance gas-anesthesia with isoflurane 1% alcoholic preparation. Both upper legs can be fixed in
to 2% supplemented with oxygen 1 L/min is administered by relaxed extension, taking care to avoid brachial plexus
mask ventilation with spontaneous breathing. Rabbits are injury caused by overstretching of the limbs.
obligate nasal breathers, and as such, a mask firmly attached
around the nose provides adequate inhalation of isoflurane. Tracheal surgery
Rabbits are monitored with pulse oximetry. It is important The neck is opened via a vertical midline incision to expose
to work in an adequately-equipped environment with the superficial investing fascia. Deep to this fascia, the paired
proper ventilation and a scavenging system to minimize sternocleidomastoid and strap muscles are divided via their
spills. Upon orthotopic transplantation, it is useful to connecting raphe, forming a bloodless plane at the midline.
have a sterile tube available in the operating field which The raphe is opened from the thyroid cartilage to the sternal
can be inserted into the distal tracheal segment at the notch to expose the cervical trachea over its entire length.
moment that the trachea is opened. Upon approaching the sternal notch, the venous jugular
arc is encountered, running deep to the distal part of the
Euthanasia sternocleidomastoid muscles and crossing the midline. The
Rabbits are euthanized by intravenous injection of a lethal branch is ligated and an orthostatic retractor is placed to
dose of T61 0.3 mL/kg into the marginal auricular vein. When provide adequate exposure [Figure 4]. The trachea is covered
the trachea is used for transplantation or in vitro research, by pretracheal fascia. The thyroid gland is also incorporated
it is important to limit warm ischemia time. [20,21] Therefore, into this fascia, and can be divided along the midline while
opening of the neck is performed under general anesthesia. opening the fascia longitudinally. The cervical trachea is then
Only after exposure of the entire tracheal length, is the circularly detached from the surrounding tissue.
euthanizing agent administered and the trachea procured.
The recurrent laryngeal nerve travels within the tracheal-
OPERATING TECHNIQUE esophageal groove and enters the larynx on the posterior
surface of the trachea. The nerve is identified and dissection
[22]
Tracheal surgery as well as flap dissection can be performed is pursued close to the trachea to avoid vocal-cord paralysis.
Plast Aesthet Res || Volume 3 || July 7, 2016 227