Autopsy Techniques

As at least some of you have finished clinical appointment and seen autopsies being carried out I thought of giving you an overview of the different techniques of dissection practised in different centres around the world.

As you may have already seen our standards of autopsy dissection is way below that of the developed world. It is not that we lacked the expertise or time. Just as everything else in our society it is the lack of correct attitude and accountability.

It is the standard of practise all over the civilised world that the skin incision and dissection of the organs should be done by a suitably qualified doctor. Where there are trained 'autopsy technicians' they can eviscerate the organs after the body cavities are opened by the doctor. Even if the 'de facto' situation may differ from place to place I cannot imagine a mortuary in the developed world where the 'specialist', or any other doctor for that matter, comes to the mortuary after the untrained 'labourer' has made the skin incision, eviscerated and dissected the organs just to see the cut section wearing a 'offce attire' with the tie tucked into the pocket and to peep through the body cavities to see whether any thing is wrong.

At least some of you would be posted as DMOs and MOs-Medico-Legal in the near future. Whatever we would teach you during this brief period of you lives, I am sure that it will not retain in your brains, at least in a great majority. You would also follow this age-old path well trodden by your colleagues of bygone era as it is the norm, easy, less messy, quick etc and moreover, there is no body to oversee your work. It is also called lack of accountability both to your immediate supervisors and to the society at large. Anyway, I accept that blame cannot be entirely doctors' as the authorities who is responsible for providing facilities should also be held responsible for the 'status-quo' as doctors need decent place to enjoy their work.

Without wasting your valuable time  I would like to introduce to different techniques of autopsy dissection. Although history of autopsy techniques is interesting I am not going to dwell in there as most of you may not be concerned with such information.

There are basically four autopsy dissection techniques and many modified versions. 

Roakitansky's

Karl Rokitansky developed this technique in early nineteenth century. The basic idea is not to disturb the connection between the organs as much as possible. Each organ is dissected in situ. If abnormal anatomic relation is found the regions should be removed intact. It is, in other words, a combination of  'in situ' dissection with 'en bloc' removal (which will be discussed later). It can be performed by a single examiner. Disadvantage is that the prosector needs certain degree of pathological knowledge to identify the abnormal relationship.

 

Virchow's

 

It was developed by Rudolph Virchow (a German doctor considered to be the father of modern pathology. Remember Virchow's Triad?) The basic principle is to examine all organs systematically and to arrive at diagnosis as quickly as possible.

 

First the cranial cavity is opened and brain is dissected in the fresh state. The spinal cord is removed from the back. Abdominal cavity is opened and then the thorax. The organs are removed one by one. First from thorax. Then neck followed by abdomen.

 

They are dissected outside. This approach is good in demonstrating pathological changes in individual organs.  Advantages are its systematic stepwise approach and its simplicity. Disadvantage is the destruction of anatomic relationship of various organs making it hard to interpret findings

 

En Bloc (Ghon's)

 

In this method all the connection between physiologically connected organs are retained. The organs of the neck and thorax were removed in one block before the peritoneal cavity is opened. The gastro-intestinal tract with mesentry attached is removed. This technique is attributed to either Zenker or Ghon.

Advantages are the preservation of the important anatomic relationship and easy to handle organ blocs.  Disadvantages include the requirement of skill to remove the blocs and possibility of some diseases having multiple system involvement making the separation of blocs not conducive to proper evaluation. 

 

En Masse (LeTulle's)

 

In this technique the cervical, thoracic, abdominal and pelvic organs are removed as a single organ mass. Then they are dissected into organ blocks. Advantages are complete preservation of relationships between organs and vasculature. The speed with which it can be learned and performed is another advantage. The body can be handed over to the undertaker with no time. The negative point is the large organ mass which is difficult to be handled. This technique is attributed to Heller and LeTulle.

 

The Rokitansky technique has gone out of favour but skill in this technique may be advantage in certain autopsies as the permission to do the dissection is restricted e.g. high risk autopsy. Modern autopsy techniques include modifications of Virhow, En Bolc (Ghon's) and En Masse (LeTulle's) techniques.

 

Whatever the autopsy technique is adopted by the pathologist he/she should be prepared to modify it for the best demonstration of the pathological process which has caused the death.

 

In Sri Lanka a great majority of the forensic pathologists, who perform the dissection by themselves, like the 'En Masse' or 'LeTulle's technique as it is quick though the organ mass is pretty cumbersome to handle.

 

I personally like Gohn's 'En Boc' method as it gives you organs masses, which are easier to handle. Since the oesophagus and aorta are separated from the stomach and the abdominal aorta respectively this method has to be modified in cases of suspected oesophageal varices and abdominal aortic aneurysms.

 

This is the way I would do my dissection.

 

a. Mastoid to mastoid cut on the scalp. Separate and the anterior half and posterior half of scalp from the skull separating through the loos areolar tissue beneath the galea aponeurotica.

b. Make a horizontal cut across the temporalis musles. I do not recommend their removal as they can be sutured together when the skull is reconstructed to give it an added strength.

c. Using the bone saw (preferably the electric saw) a horizontal cut is made on skull, which runs through the frontal eminences in the front 1-2 cm above the superior margin of the orbits, through the squamous temporal bones along the cuts made on the temporalis muscles in the sides 2-3 cm above the ears and through the occipital bone 2 -3 below the lambda on the back of the skull.

d. Dissect the dura and remove the brain. (if a special neck dissection is not required the removal of the brain can be done later. Although I dissect all my cases myself the removal of skull is usually done by the 'autopsy assistant'.)

e. Make a 'U' shape skin dissection on the sides of the neck from mastoids over the clavicles (approximately over the junction between the medial and lateral halves) to a point slightly below the sternal notch over the sternal angle.

f. From that point a vertical incision is made to the pubic symphysis.

g. Abdomen and chest cavities are opened cutting across the sternum just below the first rib keeping the attachments of the clavicles and first ribs to the remaining part of the sternum intact. This may help the undertakers to reconstruct the body more easily. 

h. Then all the neck organs together with chest organs are removed in a single block after tying and cutting across the oesophagus and thoracic aorta.

i. Bowels from the duodeno-jejunal junction to recto-sigmoid junction is removed with or without mesentry (if the mesentric arteries need to be dissected the bowels are removed without it.) after tying both ends.

j. Then the rest of the abdominal organs are removed as a single block or

k. The liver is separated first.

l.  Then the duodenum, stomach, pancreas and spleen as a single bloc

m. Rest of the retro peritoneal structures aorta, IVC, kidneys, ureters, bladder, uterus, a part of the vagina and the rectum are removed as a single block after cutting through the all the structures at the floor of the pelvis.

 

This  could be called a modified En Block or Ghon's technique.

 

Priyanjith Perera

25/12/2012