A state of Injustice - - Dr Robert N Moles

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Chapter Three - Autopsies

A death in sudden or unexplained circumstances comes within the jurisdiction of the Coroner. It is usual practice for a police officer to be attached to the Coroner’s Office to attend such incidents. This officer liaises with the other police at the scene to determine if a forensic pathologist should be called in before the body is moved or removed. The Coroner’s police officer arranges for the removal of the body to the mortuary for an autopsy. Under the Coroner’s Act, the Coroner has to determine, if possible, the cause of death and if any further steps need to be taken. After the autopsy is done, the Coroner has to decide if there is a need for an inquest, which is a formal and usually public coroner’s hearing into a death.

The autopsy

The procedure of examining a dead body to determine the cause of death is called an autopsy. The word comes from Greek words meaning ‘to see for oneself’. The procedure is sometimes called a ‘post-mortem examination’, or even (colloquially) just a ‘post-mortem’ or PM.

A forensic autopsy in the case of a suspicious death differs from a hospital autopsy. Whereas a hospital autopsy is primarily an internal examination of a body for disease, the forensic pathologist doesn’t only for disease but also for signs of trauma, injury or foreign objects such as bullets, as well as clues to a suspect, to try to determine how and when the death occurred. This information may exclude a suspect by showing that the death was really a terrible accident, for example. Equally, it may show that a suspect’s account of how the death occurred is not true. [1] Thus a timely and competent autopsy is fundamental to the proper investigation of any suspicious death. Basic knowledge of the procedures involved and what they can show is therefore helpful to an understanding of some of the cases in this book and for this reason we now discuss how an autopsy is done.

The pathologist must be objective and operate in accordance with proper scientific standards. The obligation is to elicit as much information as possible to enable an assessment of the cause of death, and to record the observations in such a way as would enable another pathologist to provide an independent and properly informed opinion.

In unexplained deaths where there is access to a relevant medical history and there was medical supervision prior to the event, the pathologist will have some idea of what to look for and expect. With suspicious deaths, the examination is far more extensive and many more tissue samples are taken. The first thing to establish is whether the death resulted from an accident or homicide or natural causes. As someone may later be charged with murder, for example, based on the autopsy results, the evidence from the pathologist must be able to prove the cause of death beyond reasonable doubt if at all possible. Therefore the pathologist must be open to all explanations for the death, including those consistent with innocence, and these must be excluded before a finding of guilt can be achieved. For example, where a person has been assaulted and is now dead, it might be natural to think that the assault caused the death. However, that is only one possibility – one that needs to be confirmed beyond reasonable doubt. Another possibility is that the assault was merely incidental or coincidental to the death. The person could have died from a heart defect. The assault may have had nothing to do with the death. The pathologist has to examine (and exclude) any other reasonable alternative, as well as provide positive information which connects the observable injuries with the outcome. A proper chain-of-causation has to be established, so that each of the events leading to the death can be placed in their proper order. It is essential to establish, for example, whether the deceased died before or after being stabbed, or before or after the car they were driving crashed.

The pathologist must read all the background information about the person. If acting under coroner’s instructions, any further information can be obtained via the Coroner’s Office, as it has the power to demand information be provided. In such a case, a Report of Death to the Coroner form will have been completed. The Coroner has to issue proper instructions for the autopsy to proceed. The appropriately completed forms and permissions should be kept on the file.

Preparation for the autopsy

The pathologist wears the normal surgical theatre dress – boots, surgical gown with plastic apron, gloves and goggles. The mortuary technician has the various pieces of equipment ready. These include an array of knives for cutting, forceps for moving, a ladle for dealing with fluids and a saw for cutting bone. The saw used is an oscillating saw specially designed to cut hard surfaces such as bone. It will not cut soft tissue, such as the pathologist’s fingers.

A crime scene examiner should be present at the autopsy of all suspicious or unexplained deaths. The officer takes notes of the procedures and colour photographs or a video recording of the sequence of the autopsy.

The pathologist keeps personal notes of observations and procedures, which are written up afterwards. A pathologist may be conducting a number of examinations shortly after each other and it would be easy to be unsure of specific observations, even a short time later. Some pathologists dictate notes into a tape recorder, others write them as they go. Examination suites nowadays are likely to be fitted with closed circuit television to enable video recording of examinations. This also allows easy observation by colleagues or trainees.

The notes, tapes, photographs and samples must be clearly identified and kept secure. There should be a clear audit trail in relation to each item which identifies who has accessed it and when.

The external examination of the body

The body is undressed and any jewellery removed (where appropriate) and documented.

The pathologist conducts a full external examination of the body. If written notes are being used, then a body chart (a pre-printed outline sketch of a person) is used to provide details of locations where injuries are found.

There must be full documentation of all details including birth marks, skin blemishes, tattoos, scars, colour of hair and eyes, false teeth, missing teeth, lacerations, bruises, fractures and injection sites. It must be confirmed that the body is the same as that from the scene of the death and recorded in the register book or computer records. It is important to turn the body over and examine the back, and to look for possible trace contact material. This evidence might include fibres, semen or soil stains and scrapings from under the fingernails, all of which must be recorded and collected

At this point X-rays may be taken to identify or confirm fractures (especially in children), detect bullets in shooting cases, or to check against dental records for identification purposes in the case of an unknown person or a badly mutilated or decomposed body. Fingerprints may also be taken.

The internal examination of the body

As far as possible the pathologist ensures that marks from the autopsy do not show above the shroud or shirt in which the body will be later dressed as friends and family will want to make their farewells after the examination.

Opening the body cavity

Frequently the mortuary technician makes the initial cuts, although the pathologist attends to any areas where there may be complications. What we say about the standard procedures will always have this caution in mind. If, for example, the person had been strangled or shot, then any procedures would have to ensure that evidence of those injuries is preserved.

The pathologist makes various cuts with a scalpel to open up the body cavity across and along the body to open it up. The skin and soft tissue are peeled back and the ribs and breast plate removed so that the organs can be accessed for examination. The neck and bottom part of the jaw are cut and the tongue brought down so the throat and mouth can be examined in detail.

Organs released

The connections to the organs are severed so that the organs can be removed in one block. The blood vessels that supply the legs are disconnected. About 50 mls of blood is taken from these vessels to test for various drugs (including alcohol) and poisons. Some may be kept for DNA testing to resolve any identification issues. A sample of urine can be obtained by making a small cut in the upper surface of the bladder.

The next step is to remove the organs, which are removed as a block. Once this is done only the body shell remains. The blood and other fluids will be ladled or sponged out by the technician and the pathologist will look inside to check the linings and coverings for fractures, bruises or other signs of injury or disease.

Individual organs separated

The individual organs are cut away from the block and examined, commencing from the back. The major blood vessels, the inferior vena cava and the aorta, are identified and opened along their length to expose their interior, and then removed. The vessels branching from those are also examined. The pathologist is looking for signs of an aneurism (a rupture to the blood vessels), blood clots or other blockage, or injury or disease. The renal arteries which lead to the kidneys are checked and the kidneys removed. Sometimes the organs may not be removed but just cut along their length to examine their interior. This is less thorough than removing each organ separately and weighing and examining it. The ureters which conduct urine from the kidney to the bladder are then examined as well as the adrenal glands.

The thoracic and abdominal blocks are then separated. The oesophagus is released for removal with the stomach as part of the abdominal block. The diaphragm is released from the abdominal block and removed with the thoracic block.

Abdominal, pelvic and upper thoracic blocks

From the abdominal block, the oesophagus and stomach are opened and a sample of the contents of each is taken. The various abdominal organs are inspected in situ. The pelvic block is removed from the abdominal block and pelvic organs, such as the prostate in men and the ovaries in women, are examined. The heart, which is in the thoracic block, is removed by cutting the vessels which lead to it. That block is then turned over, and the airways examined, including the larynx, trachea, bronchi and lungs. The vessels of the heart are opened, as is the part of the aorta leading from it. All the remaining organs are dissected out: the lungs, heart and thyroid from the upper block, and the liver, spleen and pancreas from the lower block. Each organ is weighed and then examined in detail.

The further examination technique depends very much on what is required. One approach is to cut down the bronchi and airways of the lungs. However, as any technique for examination will (at the same time) destroy the organs or vessels, the pathologist will be very much guided by whether there is a need to demonstrate some process, or to obtain samples for further testing.

With the heart, there are many different techniques. One is to work through the chambers  and open up each of them in the order in which the blood flows through them. However, this might lead to them being unrecognisable afterwards.

Photographs are an important part of recording both the sequence of events, and the findings, especially in traumatic deaths, whether the death arises from assault, or car, workplace or recreational accidents. In criminal matters, a full sequence of photographs must be taken, usually by the crime scene examiner.

Ancillary investigations

All autopsies should be complete and the examination not restricted to areas of presumed or obvious pathology. An autopsy is not considered complete unless it is accompanied by the appropriate ancillary microscopic (histology) and chemical (toxicology) investigations. [2]

Histology

Histology is the examination of body tissues using a microscope. This detailed examination is an essential aspect of an autopsy. In a suspected criminal case, the pathologist should take as many tissue samples for histology as possible. It is better to take to many samples rather than not enough in such cases, as it is impossible to know what questions will eventually turn out to be important.

Tissue samples should be taken from organs such as the heart and lungs at least. The minimum required for each lung is four samples - two from the upper (left and right) lobes and two from the lower (left and right) lobes. In addition, it is essential to take samples of any abnormality. With the heart, tissue samples should be taken from the different areas of the blood flow within the heart, and of portions of the coronary arteries that supply blood to the heart itself. The arteries are opened and examined for blockage. A heart attack caused by a blocked artery does not necessarily damage the heart itself. The failure to appreciate this can lead to an impaired diagnosis of ischaemic heart disease or the failure to diagnose a heart attack (myocardial infarction). Ischaemia means an inadequate supply of blood to a part of the body. A myocardial infarction is where the muscle of the heart is irreversibly damaged due to a loss of blood supply. It may not be possible to find evidence of infarction as it takes about six hours for the effect of this to show up within the heart. Thus, if the person dies within one hour of the heart pain, for example, then heart tissue samples taken at an autopsy would not reveal anything even when examined using a microscope. However, by opening up the coronary artery, the pathologist can see any thrombus (clot) within it. Sound practice is to take samples from the coronary arteries for histological examination.

When pathologists see evidence of a heart attack, they have to relate these observations to what has occurred. Did the heart attack cause the accident, or was the accident the cause of the heart attack? The people who were present at the incident may not be able to relate accurately whether the person was alive or dead when they were stabbed. This may be due to their incomplete knowledge of the circumstances, or the fact that they may have been affected by drink or drugs.

The procedure for taking histological specimens is to cut representative blocks of tissue from areas of abnormality and also from normal tissue (as controls) for comparison. These blocks are placed in formalin, which fixes (hardens) the tissue. The next day, the hardened tissue can be sectioned. To do this, pieces about 2 cm x 1.5 cm in size and about 2–3 mm thick, are cut from the original blocks, trimmed to fit in a cassette and impregnated with molten wax. Additional procedures ensure that the tissue is properly positioned within the wax block, and that the block itself can then be positioned so that it can be placed on a microtome – a machine which will take off very fine slices (sections). In effect, the wax is holding the hardened tissue in position so that wafer-thin slices can be machined off it. The sections are adhered to microscope slides and stained with various dyes that will react with the tissues to produce different colours so that they can be properly identified using a microscope. The piece of tissue finally examined by the pathologist is quite small and its selection from the larger piece of tissue should be done by the pathologist and not by the technician. Under the National Association of Testing Authorities (NATA) accreditation (which is the Australian standard for laboratory accreditation) the pathologist is not allowed to get the technician to cut up the tissue specimens. Where it is just a matter of the tissue being transferred, say from the microtome to the slide, then the technician may do that, but if selection is involved, then it is the pathologist who must make that selection. This is demanding on the pathologist’s time, as they have to return to the laboratory 24 hours after the block tissue sample has been taken from the body to do the next stage. However, good laboratories should insist that the pathologists do the trimming and selection of tissue samples and organise schedules accordingly.

Samples for histology of lung, heart, spleen, liver, brain, kidneys and any abnormality should be routine. If a death is suspicious, then it is essential to take many more than that. If a body is found at home and is of a young and apparently fit person, and an autopsy as described above had not revealed any apparent cause of death, then it would be essential to take further action.

Toxicology

Usually decisions about toxicology are taken at the end of the examination. If the autopsy and histology have been of little of help in revealing the cause of death, a full toxicology screening should be done. Initially this involves screening the blood and (perhaps) urine as well. Samples of liver tissue and stomach contents, and sometimes bile, might be taken. The pathologist screens the urine and blood for drugs such as cannabis and amphetamines as well as alcohol – this is where any known social history of drug taking can be of great  help. It is very important to know what drugs or medications were found at the scene and for screening to be undertaken for them. Samples from containers taken from the scene would need to be analysed as well, as it would be unsafe to assume that the contents of containers corresponded with the description on the labels. If a volatile solvent such as chloroform or petrol is thought to be involved, lung tissue will reveal if vapours from such a solvent have been inhaled.

It is important that the pathologist is given as much help as possible in what to look for. Lawyers and police should appreciate that social and medical history is important and that any relevant information should be provided as quickly as possible to the pathologist so that appropriate tests can be conducted quickly and some of the possible causes of death eliminated.

Specialist examination

The most obvious organs for more detailed examination are the brain, heart and liver. The first thing to consider is if the brain should be sent to an expert neuropathologist. The whole brain needs to be sent as it is better for the specialist to section it as the tissue is so soft.

The brain

To examine the brain, the top of the skull is removed and nerve connections are examined and cut. The connection to the spinal cord is also examined and cut. Removing the brain is a delicate job, and must be done carefully. The brain is then examined externally for haemorrhage or swelling.

Death caused by a haemorrhage, such as a subarachnoid haemorrhage can be seen on visual inspection. This is bleeding outside the brain itself but beneath the membrane which covers the outer edge of the brain (the arachnoid membrane). An internal brain haemorrhage is likely to be seen either by the blood spilling out through the tissues of the brain, or where an area of the brain looks swollen. If such a haemorrhage is observed at this stage, the pathologist may decide that this is sufficient evidence to diagnose the cause of death and will not send the brain to the specialist.

If the brain is being sectioned at autopsy, the pathologist takes a long knife and slices through the centre of the brain to minimise damage. At this stage there will be some leakage of red cells, which would (to the untrained eye) look like bleeding. However, a pathologist should be able to distinguish such leakage from bleeding that had occurred during life.

It is often said that a loss of consciousness has no pathology. So, if someone has lost consciousness before death there may be no physical evidence of this in the examination of the brain at autopsy. If a dead person has (external) bruising to the head, it may be difficult to determine whether they hit their head and became unconscious or became unconscious and hit their head. There may be no physical signs within the brain of the initial loss of consciousness. Epilepsy is perhaps the most common occurrence of such an event, but it is by no means the only possible cause.

The heart

At a normal autopsy, somewhere between four to twenty tissues samples may be taken of the heart. When a specialist cardiac pathologist examines the heart, some 300 to 400 samples may be examined. This enables the specialist to pick up on faults or damage within the heart which would not otherwise be apparent.

What a specialist can bring to an examination highlights the need for peer review in forensic pathology, and the need for all pathologists to be in constant contact with other specialists in their field so that they can check each other’s cases and keep each other informed. Where a pathologist is working essentially on their own, without frequent exchanges of files, slides and ideas with colleagues, there is a potential problem. Lack of knowledge, or missed opportunities for updates go unnoticed. Any quality management procedure should require regular, routine and systematic peer reviews to be undertaken. Blind checking by pathologists from another laboratory of notes, files, reports, analyses and procedures used, is one way of doing this. It is an integral part of risk management.

General issues

Bruising

A pathologist must be able to substantiate the fact that a mark is a bruise as opposed to any other form of skin discolouration or blemish. Bruising results when blood vessels are damaged sufficiently to allow blood to escape through the walls of the vessel into the surrounding tissues beneath an intact skin, leading to discolouration which can be seen through the skin. [3] Not all bruising is visible to the naked eye. Blood has to escape in sufficient quantities for it to be visible through the tissues and skin. Many factors, for example skin colouring and the existence of tattoos or other marks, influence the extent to which a bruise can be seen on visual examination. Peeling back the skin over suspected areas of bruising can confirm bruising, as can taking tissue samples for microscopical analysis.

Normal procedure is to photograph the visible mark or suspected area, peel back the skin and photograph the tissue, then take a tissue sample and photograph the area again. Thus a complete record is kept of each stage of the procedure. Microscopical examination can then confirm the existence of red blood cells within tissue where blood is not normally found

The body reacts to ruptured blood vessels by utilising fibrin to stem the flow of blood and sending neutrophils (a type of white blood cell that acts as a scavenger) to mop up the escaped blood. If neutrophils are seen in tissue samples taken from the site of the bruise when examined under a microscope, bruising is confirmed

It can take up to 24 hours, and sometimes longer, for this neutrophil reaction to take place. In one person it may happen within two hours, and for another person it may still not have happened after 24 hours. Therefore telling the age of bruises based on this process is a vexed question. All the pathologist can do microscopically is to determine whether or not the reaction has occurred, but not when the injury that caused the bruise occurred

The pathologist should try to determine if any bleeding is along the septal planes (that is, between the tissue surfaces), or whether it is diffused within the tissue. This is because is not uncommon to go back to the body after 24 hours and see bruising which was not apparent upon the first examination. Bruising sometimes appears more obvious a day later. However, if the pathologist doesn’t notice bruising at the first examination, but does notice it at a subsequent examination, then careful consideration must be given to the fact that it could be bruising (or bleeding) which has been caused by the process of the autopsy itself (artifactual bruising).

Because the autopsy process involves cutting through tissues, it invariably causes bleeding. If proper care is not taken, such bleeding might subsequently be thought to have occurred during life. For example, when the scalp is peeled back from the skull, the process causes blood to escape from the many tiny blood vessels across the scalp. It is likely that this blood will collect along the line where the scalp is still joined to the skull. Gradually, blood will seep between the skin and the tissues. If the scalp is then peeled back further after a period of, say, 24 hours, a pathologist would expect to some pooled blood in the tissues where the skin was further taken back. Any bleeding or bruising found in such areas must be distinguished from bleeding or bruising which had occurred during life.

Virtopsy

The term virtopsy was created from the words ‘virtual’ and ‘autopsy’ to describe a virtual autopsy – an autopsy performed without dissecting the body. It uses computerised imaging and radiology technology to create two dimensional and three dimensional reconstructions of the body from which an objective and reproducible assessment can be made. This procedure is not yet in general use, but studies show it to be practical and reliable and it could become an established technique. Its advantages include its non-invasiveness, its potential for teleconsultation between colleagues, and its ability to use the data for teaching and in court reports and demonstrations. [4]

Documentation protocols

For a sudden or unexplained death investigation, a properly documented medical history is essential. In Australia, a person can seek medical assistance from a number of practitioners, none of whom may know about the others. The only way a pathologist can be confident of obtaining relatively complete information on someone brought in for autopsy is to check through the Medicare system. Medicare maintains records of payments and treatment providers and the Coroner has the power to request such information.

In suspected criminal cases, the pathologist must avoid any unauthorised contact with the family or friends of the deceased, just as a judge would do during a trial. While it can sometimes be helpful for the pathologist to discuss matters relating to the deceased with the family or friends it is necessary to get the permission of the Coroner before doing so.

The autopsy report

At the completion of the autopsy a formal report is prepared. A typical report begins with information concerning the identification of the body, followed by a description which includes age, sex, race, height and weight. [5] Clothing is described, and then the findings from the external examination are described- items such as hair and eye colour, scars, tattoos and any other identifying features. Injuries are described in detail.

The information from the internal examination describes the various systems of the body – respiratory, cardiovascular, alimentary, renal, endocrine, haemopoietic, central nervous and skeletal – and follows the pattern of the dissection. A record is made of the results and meaning of samples that have undergone histological or toxicological testing.

The report concludes with comment on what was directly or indirectly responsible for the death – the ‘cause of death’. The language used for this should be as simple as possible as it needs to be understood by non-medical people such as lawyers and possibly jurors. In some cases it is appropriate to comment on the ‘manner of death’. For example, commenting that the injuries found are likely to have been self-inflicted.

In a court hearing an expert witness is often pressured to be more accurate than the science sometimes allows. It is always inappropriate for an expert witness to express views that go beyond their own scientific capabilities. The pathologist’s findings and interpretations must be based on what they have actually observed, and on accepted scientific principles. Speculating on the circumstances surrounding the death should be absent or kept to a minimum [6] – It is not the job of the pathologist to speculate as to how something may have happened, only to be able to prove that it has.

Endnotes

1. JS Sexton & GR Hennigar, ‘Forensic pathology – the hidden speciality: a survey of forensic pathology training available to medical students and residents’, Journal of Forensic Sciences, no. 24, 1979, pp. 275–81.
VJ DiMaio & D DiMaio, Forensic pathology, 2nd edn, CRC Press, Boca Raton, Florida, 2001, p. 547.

2. VD Plueckhahn, Lectures on forensic medicine and pathology, 5th edn, University of Melbourne, 1982, p. 118.

3. C Capper, ‘The language of forensic medicine: the meaning of some terms employed’, Medicine, Science and the Law, no. 41, 2001, pp. 256–9.

4. MJ Thali, K Yen, W Schweitzer, W P Vock, C Boesch, C Ozdoba, G Schroth, M Ith, M Sonnenschein, T Doernhoefer, E Scheurer, T Plattner & R Dirnhofer, ‘Virtopsy, a new imaging horizon in forensic pathology: virtual autopsy by postmortem multislice computed tomography (MSCT) and magnetic resonance imaging (MRI) – a feasibility study’, Journal of Forensic Sciences, no. 48, 2003, pp. 386–403.

5. AA Moenssens, RE Moses & FE Inbau, Scientific evidence in criminal cases, Foundation Press, New York, 1973, pp. 174–6, . 212–21 (example of report).

6. VJ DiMaio & D DiMaio, Forensic pathology, 2nd edn, CRC Press, Boca Raton, Florida, 2001, p. 549

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