Anatomical Research of the Clavicular Pedicled Flap for Mandibular Reconstruction
Condition: Mandibular Reconstruction; Maxillofacial Injuries
MeSH terms: Maxillofacial Injuries
Study type: Interventional

Summary: 
      Because of the proximity of the clavicular bone to the oral cavity, and the suitable
      characteristics of the bone for implant placement, its use as a pedicled flap is an
      attractive method of mandibular reconstruction. This research, performed on fresh cadaver
      specimens, describes the vascular supply and harvesting technique of a pedicled clavicular
      bone allowing a mandibular reconstruction with a single surgical field.
    

Detailed description: 
      An osteoperiosteal clavicular flap was harvested from the right side, on 10 fresh male
      cadaver specimens whose age of death ranged between 42 and 65 years. The dissection was
      carried out by the investigator at the laboratory of the Anatomy of René Descartes University
      of Medicine in Paris in 2004, as well as in the Forensic Medicine Department of Mohamed Tahar
      Maamouri University Hospital in Tunisia.

      Technical steps for harvesting the pedicled osteoperiosteal clavicular flap:

      The cadaver is placed in dorsal recumbency, and a pad under the shoulders. A cervical
      incision with a " Z " shape was performed in which the upper branch was placed two
      centimeters below and parallel to the inferior jawline to preserve the marginal mandibular
      nerve. The vertical branch of the incision continued following the path of the
      sternocleidomastoid muscle and reached the lower branch of the " Z " at the level of the
      clavicle.

      The dissection was carried out in the cervical region's sub-platysmal plane and the
      pre-pectoral and pre-deltoid planes. The deep plane can be approached through an incision of
      the superficial cervical fascia overlying the sternocleidomastoid muscle taking into
      consideration the spinal accessory nerve. Then, the clavicle was released from the
      sternocleidomastoid muscle, but the subclavius muscle insertion was preserved on the clavicle
      to protect the subclavian vein branches. The level of undermining dissection was confined to
      the loose fat pad overlaying the scalene muscle, within which the vessels are embedded
      without exposing the brachial plexus.

      The anterior surface of the subclavian vein was exposed, and the vessels arising from this
      vein were ligated. The clavicular bone attached to a celluloadipous pedicle has been lifted
      exposing the thyrocervical trunk. A celluloadipous tissue around the branches of this trunk
      (cervical transverse artery, inferior thyroid artery, ascending cervical artery, and
      suprascapular artery) was preserved in their dissection, and care was taken to avoid injury
      of the phrenic nerve, noticeable near the inferior thyroid artery. Then, the cervical
      transverse and suprascapular arteries were ligated at their distal part. Nevertheless, the
      inferior thyroid artery could be also ligated, which increases the total pedicle length of
      the flap and improves its arc of rotation. Otherwise, the flap will be bi-pedicled. The
      ascending cervical artery was dissected along the anterior scalene muscle up to the level of
      the transverse process of the fourth cervical vertebrae which is considered the vascular
      pedicle rotation point.

      The vascular supply of the clavicular flap was highlighted by injecting the thyrocervical
      trunk with coloured latex after ligating the following arteries at their distal parts: the
      inferior thyroid, the suprascapular, and the cervical transverse.
    

Intervention name(s): Osteoperiosteal pedicled clavicular flap for mandibular and facial bone reconstruction
Intervention type(s): Other
Intervention description(s): A clavicular flap with a vascular supply based on the transverse cervical artery which receives a reverse blood supply from the ascending cervical artery. This vascular pattern is reliable because of the existence of the sub-occipital microvascular network named the " Bosniak node ".
Other intervention name(s): Anatomical Research of the clavicular pedicled flap for mandibular reconstruction
Intervention model: Single Group Assignment
Intervention model description: The harvest of a pedicle osteoperiosteal clavicular flap was performed in the same way on ten fresh cadaveric specimens. The vascular supply was studied by colored latex and methylene blue injections.
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Clavicle; Pedicled Flap; Bosniak Node; Microvascular Network; Mandibular reconstruction