1.1.1 Principal Indications

• 
  

  Posttraumatic states, dens fractures, or pseudarthroses

  
  
• 
  

  Tumors

  
  
• 
  

  Osteomyelitis

  
  
• 
  

  Os odontoideum

1.1.2 Preparation of Patient, Positioning, Anesthesia, Incision

This approach continues to present the problem of opening spongy bone cavities in an area colonized by pathogens. Thorough oral disinfection is therefore required before the start of the operation. The procedure is performed under antibiotic protection, and antibiotics are applied locally before closure of the wound. The patient is placed in a supine position with the head lowered and the cervical spine slightly overextended. The anesthesiology team stands on one side of the patient, and the operator at the head, with the assistants standing on both sides of the head.

The transoral approach is facilitated by prior creation of a tracheotomy for anesthetic purposes. Tracheotomy is not absolutely necessary: the operation can also be performed without special problems with a transnasal or transoral tube that is laterally retracted by means of a long spatula. A gag is then inserted with a special plate that holds down the tongue ( Fig. 1.1 ). A hook is used to pull the soft palate up.

1.1.3 Exposure of the Vertebrae

An incision of the posterior pharyngeal wall is made with a scalpel in the midline, beginning at the readily palpable anterior tubercle of the atlas and extending to the level of C2 or C3. The length of the cut is approximately 5–6cm ( Fig. 1.2 ). The longus colli muscle now becomes visible ( Fig. 1.3 ); it is split in the midline. Using a rasp, the soft tissue on the anterior side of C1 and C2 (possibly also C3) is now retracted laterally, beginning at the midline. This brings the anterior tubercle as well as the lateral mass of the atlas and the body of the axis into view. The operative area is kept open with flexible spatulas, and hemostasis is effected by diathermy ( Fig. 1.4 ). The atlas can be exposed to at most 2 cm laterally from the midline, but vertebrae C2 and C3 to no more than 1 cm. At the inferior border of C2 in particular, there is a danger of injury to the vertebral artery ( Fig. 1.5 ). On the side of the lateral mass of the atlas, the rasp may penetrate the retromandibular fossa, and this may lead to injuries of the ninth and 12th cranial nerves.

1.1.4 Wound Closure

Wound closure is performed in two layers with absorbable interrupted sutures.

1.2.1 Principal Indications

• 
  

  Trauma

  
  
• 
  

  Degenerative changes

  
  
• 
  

  Tumors

  
  
• 
  

  Spondylitis

1.2.2 Choice of Side of Approach

For the upper and middle portions of the cervical spine, an approach is possible from either side. This also depends, however, on the side of the lesion. Right-handed persons generally prefer a right-sided approach, although for exposure of the cervical spine from C6 and below, the left-sided approach is preferable so that injury to the recurrent laryngeal nerve, which runs irregularly and at a higher level on the right side, may be avoided.

1.2.3 Positioning and Incision

The patient is placed in a supine position, generally without skeletal extension except in the presence of fresh trauma. A cushion is placed between the shoulder blades; if hyperextension is desired, a rolled-up pad is put beneath the cervical spine. The head is turned slightly toward the contralateral side, and both shoulders are pulled down with strips of adhesive tape. The operation is performed under endotracheal anesthesia.

The type of incision used depends on the desired extent of the vertebral exposure. If an exposure of only one or two segments suffices, a transverse skin incision parallel to the skin creases of the neck is recommended. The level of the transverse incision may be chosen according to the following guide:

• 
  

  C3 and C4: incision two fingerbreadths caudal to the mandible at the level of the hyoid bone

  
  
• 
  

  C4 and C5: incision at the level of the thyroid cartilage

  
  
• 
  

  C5 and C6: incision at the level of the cricoid cartilage

  
  
• 
  

  C6 and T1: incision two fingerbreadths cranial to the clavicle

For a long exposure of the cervical spine involving several segments, a longitudinal incision in front of the sternocleidomastoid is preferred. The skin incision begins at the level of the mandibular angle and extends distally as far as the manubrium of the sternum ( Fig. 1.6 ). The platysma is split in the same direction and moved to the two sides to expose the superficial cervical fascia. This is now transected longitudinally at the anterior border of the sternocleidomastoid. This usually also requires sectioning of transversely coursing cervical veins and branches of the transverse cervical nerve ( Fig. 1.7 ). The sternocleidomastoid is then retracted laterally and the subhyoid medially. The upper belly of omohyoid now extends transversely across the operative site ( Fig. 1.8 ). Undermining this belly, it is transected between two ligatures and retracted on both sides. Then the pretracheal layer of the cervical fascia is opened by blunt scissor dissection. The cervical vertebrae can now be palpated with the finger. Veins running transversely deep to the fascia (middle thyroid veins) often need to be transected between ligatures ( Fig. 1.9 ). The pretracheal fascia should then be bluntly dissected cranially and caudally, sacrificing transverse branches of the deep ansa cervicalis. The pulse of the common carotid artery can be palpated laterally with the finger. The neurovascular bundle (common carotid artery, internal jugular vein, vagus nerve) is cautiously retracted laterally, while the visceral structures (trachea, larynx, thyroid, and sternohyoid and sternothyroid muscles) are retracted medially ( Figs. 1.9 and 1.10 ).

1.2.4 Exposure of Cervical Vertebrae C2–C6

Further dissection, in the medial and cranial directions, between the prevertebral layer of the cervical fascia on the one hand, and the esophagus and larynx on the other hand, is best done with the finger. If further dissection in a cranial direction for exposure of the third or second cervical vertebra is required, the superior thyroid artery must be found, ligated, and transected ( Fig. 1.11 ).

1.2.5 Anatomical Site

( Figs. 1.12 and 1.13 )

The following anatomical structures need to be considered when exposing the proximal segments of the cervical spine: superior thyroid artery, lingual artery, and facial artery, all of which branch off from the external carotid artery and may be ligated if necessary. The hypoglossal nerve, which runs from its cranial origin caudally and then takes a medial turn in front of the external carotid artery to enter the lingual muscles, should be spared.

The superior laryngeal nerve with its external and internal branches originates from the vagus nerve and courses deep to the lingual and facial arteries before entering the larynx. Further cranially, coursing in a medial direction from the base of the skull, the glossopharyngeal nerve runs into the superior constrictor muscle of the pharynx.

The irregularly coursing veins may be ligated if necessary ( Fig. 1.14 ).

The approaches are represented schematically in Figs. 1.15 and 1.16 (red arrows).