Registrar Datos para Análisis de Necesidades

On completion of the external examination, an internal examination is carried out. This part of the autopsy involves an examination of each of the body’s main cavities and the organs within them. These cavities include the cranial, thoracic and abdominal cavities, but in addition areas such as the head, the face, the neck, the spine, the limbs, the pelvis and the genitalia are also examined. The basic instruments used in these procedures are the same as those used in routine surgery. While the exposure of the body contents is more extensive during an autopsy, the way in which incisions are made and the organs dissected is again only a minor modification of routine surgical techniques.

The internal examination of the body may be performed in a variety of ways as detailed below.

In practice, the method chosen will depend on the medico-legal issues that need to be addressed and the state of the human remains (burnt, decomposed, traumatised or skeletonised).

[33.760]

The conduct of the internal examination of the body at autopsy involves a systematic examination of the organs and tissues found within the body cavities and the solid tissues forming the musculoskeletal system. The recording of this process may be documented using an anatomical or body system approach. In either case a high degree of importance is placed on the use of objective descriptive terms in the report that are later interpreted in relation to their significance regarding the presence of injury or disease. The cranial cavity, the thorax, the abdomen and the pelvis comprise the regions of the body that receive the most attention during the internal examination. Not only are the major organs from these cavities examined but also the walls of the cavities themselves are assessed for characteristic features and signs of disease.

The visual inspection of internal body organs is only one part of the physical autopsy process.

Some diseases only involve alterations to the microscopic appearances of body tissues. In other

cases a disease will be visible first as a microscopic change to the body tissues that precedes any changes to the “naked eye” appearance of the relevant body organ. An example of the latter can be seen in the case of “myocardial infarction”, one of the pathological processes that can cause a heart attack. This pathology occurs when parts of the heart muscle are starved of blood and die. It may take several days of survival for the dead areas of heart muscle to become visible to the “naked eye” and if the patient dies before this, the macroscopic autopsy may be unrevealing. However, the microscopic signs of damage are visible much earlier (in the case of electron microscopy after a matter of hours) and therefore it is essential that the heart muscle is examined under the microscope. In practice the only way to ensure that these issues are covered is to perform routine microscopy on all body tissues. Of course, it is logistically impossible to examine all of each tissue microscopically but adequate sampling can be achieved so that the best possible pathology detection rate is established.

[33.770]

With some body organs, macroscopic examination at the time of the physical autopsy is particularly difficult. Organs such as the brain and the spinal cord are so soft and fragile that they may be damaged and distorted by the process of the dissection and tissue sampling. In these cases it is often necessary to process the organs by “fixing” them in a preservative solution in order that they can be made more rigid and capable of detailed dissection. In the case of brain diseases or trauma this is generally advisable although there are exceptional circumstances when dissection of the brain can be performed without fixation.

These comments relating to the brain are also applicable to other body organs in particular circumstances of disease so that it may be necessary to retain such organs during the physical autopsy and “fix” them for further examination. Unfortunately, the fixation process can take some time to render the organ suitable for specialist examination. In the case of solid organs such as the brain, it may take several weeks for fixation to be completed. This can result in difficulties in respect of the disposal of the body of the deceased. Families usually require that the funeral take place within a few days of the death and as a result in some cases the body may have to be buried or cremated without the organs that are undergoing fixation. For many families this poses no significant problem. In many ways the situation is no different from the situation where a person leaves hospital after surgery with a diseased part of their body having been removed and sent to the pathology department for pathological examination. What is important in both of these situations is that, following the completion of the specialist pathology examinations, the tissues or organs are disposed of in a safe, secure and decent manner. For some families, however, the fact that a deceased person has been buried or cremated without all of their organs is distressing and amounts to an incomplete disposal of their loved one. In these cases it is often possible to arrange for a second small funeral-like process for the remaining tissues and organs after they have been examined.

As well as demonstrating the presence of disease or injury, the autopsy can reveal the extent of the disease and some of the effects of treatments that have been provided. However, many disorders are the result of functional disturbances of body systems that involve abnormalities of vital responses. Unless these abnormal responses have caused macroscopic or microscopic structural changes in the body tissues, they will not ordinarily be detected by the physical autopsy. The same is true in association with deaths due to some drugs and poisons. Although such chemicals can cause visible alterations to body organs, in many cases the changes are non specific and toxicological tests will have to be performed on tissues and fluids collected from the body during the physical autopsy in order to identify them. In both these cases the physical autopsy may reveal no specific visible abnormalities. It is only by analysing the circumstances of the death, including the medical history, and collecting samples from the body for testing, that the death can be understood.

Dissection procedures

The incisions used to undertake the internal examination vary according to the circumstances and among pathologists. The safest procedure, the one most likely to identify the injuries of particular forensic interest while at the same time minimising artefact, commences with the scalp. The incision commences immediately behind the ear and passes through the mid-temporal regions to the same point behind the other ear. The scalp is then reflected forwards to the orbital ridges and backwards to the deep occipital region. The skull cap is then removed, preferably leaving the dura intact. The dura is incised, exposing the brain, which is then removed. The removal of the brain at this stage of the autopsy will assist drainage of blood from the head and neck and so minimise possible artefactual bruising during dissection of the neck. The dura over the base of the skull is then removed. The incisions behind the ears are continued down the anterolateral aspects of the neck across the mid-clavicle to the midline just below the sternal notch. At the midline the incision continues down to the symphysis pubis, skirting the umbilicus.

The skin of the neck is then reflected in the subcutaneous plane at least to the mandible, and possibly to the inferior margins or the orbit when the determination of the presence, or accurate delineation, of facial injuries is of particular significance. The skin of the chest and abdomen is likewise reflected in the subcutaneous plane to maximise the detection of bruises in these areas. The peritoneum is then incised in the midline and the anterior abdominal musculature is freed from the costal margins so that the abdominal contents are fully exposed. The skin of the chest having been reflected, the pectoral muscles are then freed from their costal and clavicular attachments exposing the ribs. At this point the pleural cavities can be assessed for the presence of air between the lungs and the chest wall (a pneumothorax). Several techniques can be employed including aspiration of pleural contents through a water trap, opening part of an intercostal space under water and dissecting the intercostal musculature to inspect the parietal pleura directly for the presence of visible surface lung markings. After the pathologist has checked for pneumothoraces, the sternocleidomastoid muscle is then reflected from its sternal and clavicular attachments. The sternoclavicular joints are incised and the ribs are cut, allowing removal of the sternum with attached portions of ribs and costal cartilages. At this point the surface of the mediastinum and the lining of the chest can be examined and any fluids in the pericardium (the sack around the heart) or within the pleura cavities can be measured and collected.

Should the examination of the neck be of particular importance, the thoracic organs can then be released below the thoracic inlet, allowing blood to drain from the neck to minimise artefactual bruising during the in situ neck dissection. The strap muscles of the neck can then be reflected, and the hyoid bone and thyroid cartilage can be inspected, having been subjected to minimal interference by the prosector. When such a detailed examination of the neck is not of particular importance, the removal of organs can proceed directly. The oral contents are freed by removing the floor of the mouth from its mandibular attachments. The pharynx is then dissected from its prevertebral attachments and the structures of the neck dissected away from the cervical vertebrae, making a conscious decision whether to include the carotid arteries. (In appropriate circumstances, leaving the external carotid arteries intact may be a consideration in relation to subsequent embalming.) The common and internal carotid arteries are then explored.

[33.790]

There are various techniques which can now be used to remove and subsequently examine the internal organs. The three main variations are as follows:

(1) Examining the organs in situ and then dissecting them out one by one. This technique basically follows that elaborated and used by Rudolph Virchov in the 19th century.

This technique is rarely used today. However, it may still have some value in situations where only a limited autopsy is permitted by law. A further modification of this procedure involves the taking of biopsies of major body organs while they remain in situ. In the case of high-risk cases where transmission of infectious disease is a substantial hazard of the autopsy, such an approach may be reasonable. However, the biopsy autopsy allows for only a very small part of the body organs to be examined with a consequent severe reduction in the amount of information that can be obtained.

(2) Removing groups of organs that are anatomically related to each body cavity and functionally related to specific body systems (ie, cardiovascular system–heart and great vessels; pulmonary system–lungs, trachea, larynx and diaphragm). These organ clusters or dissection blocks are removed together and dissected without disturbing their anatomical relationship. This technique is sometimes referred to as the modified Virchov procedure. The five principal groups of organs removed comprise:

(a) the central nervous system;

(b) the small and large intestines together with the mesentery;

(c) the contents of the thorax and neck including the tongue, larynx, trachea, oesophagus, heart, thoracic aorta and lungs;

(d) the stomach, duodenum, liver, biliary apparatus, pancreas and spleen; and (e) the kidneys, ureters, bladder, rectum and internal genitalia.

The modified Virchov technique is widely used by pathologists today. It is more commonly used in hospital autopsy practice but is equally applicable to forensic case work. Its principal advantage is that it allows the pathologist to examine more of the internal organs while they are still in the body and so still retain their attachments to the walls of the body cavities. Upon opening the chest and abdominal cavities, the small bowel (jejunum and ileum) and large bowel, excluding the rectum, is removed, allowing greater exposure of the remaining abdominal organs in situ within the abdominal cavity. This permits direct visualisation of the relationship of any penetrating injury to the skin of the abdomen with injuries to the internal organs, evidence which may be lost if all the internal organs are removed en masse.

The next step involves dissection of the front of the neck, as described above. The tongue is released from the floor of the mouth and brought down through the underside of the lower jaw (mandible). The soft palate is separated from the hard palate and all of the soft tissues of the anterior and lateral compartments of the neck, including the oropharynx and larynx, are dissected free from the cervical spinal column. Next the lungs are reflected forwards allowing the posterior chest wall and the diaphragm to be examined in relation to any disease or injury to the heart, mediastinum and lungs. At this point the oesophagus may be tied off to prevent loss of gastric contents, the lower thoracic aorta and oesophagus and inferior vena cava transected and the neck tissues and chest cavity contents removed.

To remove the remainder of the abdominal contents, the bowel mesentary is then dissected from the anterior wall of the aorta up to the level of the coeliac axis. The spleen, pancreas and liver are then mobilised and removed as one block with the mesentary and stomach, leaving the diaphragm intact in the body.

Finally the kidneys are reflected medially from each side and the pelvic peritoneum is freed from the pelvic wall and the iliac arteries and veins, urethra, rectum (and vagina or prostate) cut so as to enable removal of the entire pelvic contents in continuity with the aorta, bladder, ureters and kidneys. In cases of suspected genital injury, the external genitalia, anus and

perineum may be removed in continuity with this block using a modified version of the surgical procedure of abdomino-perineal resection. With removal of the five organ blocks, dissection of each can take place in a similar manner to the third technique described below.

(3) Removal of the contents of the neck, the thorax and the abdomen together with the aorta and diaphragm, in one large mass in a technique that has been attributed to Rokitansky and later to Leutille. The technique is commonly employed in forensic autopsies.

Mobilisation of the neck structures is followed by the freeing of the diaphragm from its attachments. The pelvic organs can be manually separated as a whole from their bony attachments and then incised at the pelvic floor. Then, preferably with assistance, the organs can be removed as a whole by finally incising the attachments to the vertebral column. The bulk of the “pluck” can be reduced substantially by removing the small and large bowel first.

This is simply done by cutting through the proximal jejunum (taking care to secure both incised ends of the jejunum if the contents are important for toxicological or microbiological analysis) and freeing it, the ileum and colon by cutting the root of the mesentary or preferable the mesentary adjacent to the bowel wall. The tissue mass is routinely dissected beginning posteriorly and working forwards. This technique preserves the relationships of organs enabling the whole length of the aorta and oesophagus, stomach and intestines to be examined intact and in relation to the surrounding organs.

[33.800]

In general, whatever the method used, it must be systematic and planned. All organs must be weighed in grams and the weights must be recorded. Abnormalities in the orientation and relationship of the various organs to their neighbours should be noted. In recording findings, accurate descriptions should be made of what is actually seen rather than interpretations or assumptions made about the lesion or abnormality. Before completing the autopsy, the prosector must ensure that all necessary specimens for laboratory and toxicological analysis, as well as all photographs and/or x-ray films which may be of assistance, have been taken. When there is doubt concerning the findings, whole organs should be retained for further study or for consultation with others.

The physical autopsy is not complete until the body of the deceased person has been restored to a state where the family as part of their funeral tradition can view it. The technical and scientific staff who are employed in assisting in this task are usually highly skilled and experienced. They are aware of the needs of the funeral industry and a number will also be qualified embalmers. In all cases the aim is to restore the outward appearance of the deceased to that visible before death. In deaths from severe trauma, specialised restorative techniques may be required to repair areas of the body damaged before the autopsy. Similarly, if large amounts of structurally significant tissue has been collected for investigation or for transplantation, such as the spinal column or the pelvis, more extensive restorative work will be required. In most cases relatively little restoration is required because the routine procedures employed in a standard autopsy are intrinsically non-disfiguring.

Reconstruction of the head and neck including the face are critical tasks which, because of the sensitivity given to facial injuries, must be carried out with utmost attention to detail. Given that a complete and thorough dissection of the face is not inconsistent with satisfactory reconstruction of a body after autopsy, there should be no reluctance on the part of the pathologist to carrying out such a dissection. When dissection of the face is limited to the soft tissues only, little alteration in facial outline should be expected. However, where the dissection involves not only the soft tissues but also the facial skeleton, then restoration of facial shape and form can be more difficult. In this situation it may be prudent for the

pathologist to obtain photographs of the body prior to autopsy and also photographs of the individual in life prior to cranio-facial injury and death.

In document UNIVERSIDAD DE EL SALVADOR FACULTAD DE INGENIERIA Y ARQUITECTURA ESCUELA DE INGENIERIA DE SISTEMAS INFORMÁTICOS (página 122-0)