Describe the examination of the neck in a suspected asphyxial death.

WHY the Technique Matters

• The neck is the one region where the pathologist can manufacture the evidence. If the neck is dissected while the head and chest are still full of blood, gravity and venous congestion force blood into the soft tissues, producing artefactual haemorrhage that is indistinguishable from the bruising of manual strangulation
• The consequence is not theoretical — an artefactual neck haemorrhage reported as strangulation could convict an innocent person of murder; and a genuine finding destroyed by careless technique could acquit a guilty one
• The rule is therefore absolute: the neck is dissected last, in a bloodless field, layer BY layer
• 1. External examination first — photograph any ligature IN situ
• describe the mark, nail marks and bruises
• look for petechiae in the conjunctivae, eyelids and behind the ears
• swab the neck for DNA before touching it → 2.
• Open the head and remove the brain, and open the chest, so that the jugular and vertebral venous systems drain → 3.
• Prop the body up with a block under the shoulders to extend the neck and assist drainage → 4.
• Reflect the skin of the neck in layers through a modified Y (V-shaped) incision, and photograph the undersurface → 5.
• Examine layer BY layer — the platysma, the superficial and deep strap muscles (sternomastoid, sternohyoid, sternothyroid, omohyoid), the carotid sheaths and the thyroid gland — recording the exact site of any haemorrhage → 6.
• Remove and examine the laryngeal skeleton — the hyoid bone and its greater cornua, the thyroid cartilage and its superior cornua, and the cricoid
• strip the perichondrium and look at each from within and without → 7.
• Open the larynx posteriorly and examine the mucosa for haemorrhage and oedema → 8.
• Examine the cervical spine and, where indicated, remove the vertebral arteries for a tear → 9.
• Take histology from every suspected bruise and from any fracture site

Interpreting the Findings

• Hyoid fracture — usually of the greater cornu, and commonest in throttling, less common in ligature strangulation and uncommon in hanging. It is found in perhaps a third of strangulations overall
• Age matters greatly — the hyoid is cartilaginous and flexible in the young, whose greater cornua do not fuse until the third or fourth decade, so it rarely fractures under 30. Its integrity therefore excludes nothing in a young person, and this must be stated in the report
• Distinguish a fracture from non-union of the greater cornu, which is a normal anatomical variant, and from an artefactual fracture produced during removal — which is common and is why the region should be dissected carefully and any fracture confirmed histologically for a vital reaction: haemorrhage at the fracture site means it occurred in life
• Fracture of the superior cornu of the thyroid cartilage is at least as common as hyoid fracture and is often overlooked; both should be sought
• Bruising of the strap muscles is significant only if it is genuine — confirmed by the bloodless technique and by histology showing extravasation with a vital reaction
• What the absence of findings means — a soft broad ligature may leave no mark and no deep injury; mugging with the forearm spreads the force and leaves little; and vagal inhibition may cause death from light pressure with no findings at all. A negative neck dissection therefore does not exclude neck compression, and the report must say so

Applied Aspects

• Never open the neck first, whatever the pressure of time; drain the head and chest, prop the shoulders, and then dissect — the five minutes saved is not worth the evidence created
• Swab the neck for DNA before touching it; an assailant who gripped the neck may have left material, and washing or handling destroys it
• Confirm every fracture histologically; an artefactual fracture from removal, or a non-united cornu, will otherwise be reported as evidence of strangulation
• State the age qualification for the hyoid; in a person under 30 an intact hyoid means nothing, and a report that implies otherwise misleads the court
• Photograph each layer as you go; the dissection is destructive and cannot be repeated, and a second opinion will depend entirely on the photographs
• Say plainly that a negative dissection does not exclude compression, and give the reasons; this qualification is what distinguishes a competent report from one that will be dismantled
• Examine the superior cornu of the thyroid as carefully as the hyoid; it fractures at least as often and is more often overlooked
• Distinguish non-union of the greater cornu from a fracture; it is a normal anatomical variant and has been reported as evidence of strangulation
• Remove the vertebral arteries where a neck blow is alleged; a tear there causes basal subarachnoid haemorrhage and instantaneous death
• Open the larynx posteriorly and inspect the mucosa for haemorrhage and oedema, which may be the only internal finding
• Prop the shoulders on a block to extend the neck; the dissection is far cleaner and the drainage more complete
• Reflect the neck skin and photograph the undersurface, as with the scalp; bruising invisible externally is often obvious from within