Autopsy: Special Evisceration

stryker saw does not cut through ST well; it will basically destroy the tissue so much cleaner and easier to reflect it

explain the rationale for reflecting the temporalis muscle prior to sawing the calvarium, as presented in lecture.

1. perfusion: inject 150 mL of isotonic saline followed by 150 mL of 10% nbf with syringe

   1. too much formalin can distort the microscopic image and dislodge obstructive emboli or thrombi

2. set brain upside down in large bucket partially filled with formalin

3. pass thread underneath arterial supply (basilar, internal carotid, or middle cerebral artery)

4. hand the string under the lid of the bucket to allow for suspension in formalin

5. rest paper towel on top before applying lid

   1. wicking purposes

6. check after 24 hours

   1. replace formalin if too bloody

7. fix for 10-14 days

describe how to fix a brain via perfusion and flotation, as discussed in lecture

1. separate eyelids with eye speculum to avoid inadvertent lid injury

2. rotate eye laterally with hook and cut the medial rectus muscle

3. rotate eye inferiorly, superiorly, medially to the cut the superior, inferior and lateral rectus muscles

4. attach clamp to medial rectus muscle to pull eye forward

5. transect the optic nerve as posterior as possible, and superior/inferior oblique and ST

6. pack the orbit with gauze or cotton and cover with plastic shield

7. fix eye for 24-48 hours in nbf

anterior eye removal

1. first remove brain and dura

2. use stryker saw to cut through the orbital roof

3. remove the bone flap with forceps

4. transect eye muscles, vessels, optic nerve and ST

5. apply gentle pressure to the globe anteriorly and remove through cranial cavity

6. pack the orbit with gauze or cotton and cover with plastic shield

7. fix eye for 24-48 hours in nbf

posterior eye removal

posterior preferred when pathology involving the orbit and eye (e.g. neoplasia, vascular disease, disease of the orbital portion of the optic nerve)

when is one eye removal approach (anterior vs. posterior) over the other?

1. radiograph - most reliable for extent and mediastinal shift

2. reflect skin and subcutaneous tissue from the chest wall - be careful not to puncture pleural cavity

3. pour water into the angle between the subcutaneous tissue and chest wall

4. use scalpel to incise the intercostal tissue below the water line

5. presence of air bubbles indicates a pneumothorax, in patients with chronic obstructive airway disease, asthma, or following trauma

6. infants and neonates: submerge thorax in water

7. alternative: insert wide bore needle attached to a 50 mL syringe (plunger removed and filled with water) into the intercostal space prior to any skin incisions:

   1. bubbles in syringe = pneumothorax

describe techniques used to detect the presence of pneumothorax at autopsy

1. avoid puncturing large neck veins during dissection and pericardial sac after the rib cage is removed

2. clamp the internal mammary vessels

3. carefully open the anterior pericardial sac and fill the cavity with water

4. incise the right atrium and ventricle to identify any air bubbles that escape

5. alternative: inserts a wide bore needle attached to a 50 mL syringe (plunger removed and filled with water) in to the RV

   1. bubbles in syringe = air emboli

Describe techniques used to detect the presence of air emboli at autopsy

1. autopsies in tropical countries

2. when proper infection precautions cannot be taken

3. when all efforts to obtain permission for a regular autopsy fails, BUT next of kin agree to multiple sampling by a needle

4. can successfully sample liver, heart, kidney, large tumors

argue the diagnostic utility of needle autopsies, as presented in lecture.

1. more acceptable to families than conventional = higher consent rate

2. central organs are sampled through small incisions

3. less invasive

4. diagnostic accuracy can vary but best when used in conjunction with CT scans

argue the diagnostic utility of laparoscopic autopsies, as presented in lecture.