The correct interpretation of the autopsy findings in a case of hanging is of importance in making a confirmatory diagnosis of death owing to hanging.
This point was made in an article on the "Profile of suicidal hanging presented to a tertiary care hospital: A descriptive study" which was authored by I.G.D. Kitulwatte, P.A.S. Edirisinghe, H.K.N.L.P. Mendis, P.R. Wijesinghe and A. Fernando (all five attached to the Kelaniya University's Medical Faculty's Forensic Medicine Department), and U.D. Senarathne (attached to the Biochemistry Department of the same Faculty of the Sri Jayewardenepura University), and published in the Sri Lanka Journal of Forensic Medicine, Science and Law's 10th Volume's Second Issue in December, 2019.
Hanging, a form of ligature neck compression that involves suspension by the neck is, as mentioned in B.R. Sharma, D. Harish, V.P. Singh and P. Singh's "Ligature mark on neck: How informative?", a common method of suicide. The role of the forensic pathologist when a body is found suspended is to give an opinion on the manner of death and to exclude or confirm other forms of neck compression prior to being hung. The correlation of the neck markings together with the internal findings are of importance in arriving at a conclusion. It is easy to arrive at a conclusion when one finds the ‘classical features’, i.e. imprint or patterned abrasion or parched appearance surrounding the neck with asphyxia features, notes an Indian study. However, all features are seldom present together. An autopsy of a hanged body will often reveal neck markings but the ligature may be absent. The findings resulting from the application of pressure on the neck vary. Thus, a forensic pathologist is caught in a dilemma when there are atypical findings in addition to the typical ligature mark. A proper assessment of the various post-mortem findings is therefore necessary in order to arrive at a conclusion.
Distinguishing signs
The nature of the neck markings depends on the type of noose. A noose made of soft material like a saree or a scarf is known to leave only a few marks or no mark at all, in turn leading to difficulties in interpretation. A rope or a cord noose will leave a deep furrow, often with accompanying abrasions. In the case of a typical suspension, the mark will rise to an inverted 'V' shape with a gap at the back. This is often used to distinguish hanging from ligature strangulation. However, in a hanging from a low suspension point, the marks on the neck, according to D. Rao's "An autopsy study of death due to suicidal hanging – 264 Cases", tend to be horizontal rather than diagonal, simulating ligature strangulation.
The pattern of external and internal injuries and other post-mortem findings resulting from neck compression permit a forensic pathologist to resolve many unanswered questions. However, as C.T. Cooke, G.A. Cadden and J.M. Hilton's "Unusual hanging deaths" observes, there are many exceptions to the rule with atypical findings. Thus, experts in forensic medicine must be aware of the exceptions in order to arrive at balanced conclusions and scientifically based opinions.
Therefore, Kitulwatte et al. conducted a retrospective, descriptive study on deaths due to suicidal hanging reported to the Colombo North Teaching Hospital, Ragama, over a period of three years. The research was conducted on the post-mortem records of the victims. Autopsy reports, scene and post-mortem photographs and other case materials such as copies of the Police scene investigation findings were perused. Bodies that were decomposed, suspicious of homicidal suspension and those with poor records were excluded.
Observations
During the period of three years, there were 112 cases of suicidal hanging deaths. Of them, 97/86.6% were males. The majority, 81/72.3% were in the age group of 21-60 years. The majority, 78/69.6% were found hanging in their own home followed by 32/28.6% victims who were recovered from places that were known to the deceased. Only two/1.8% victims were found hanging at an unknown place. There were 23/20.5% partial suspensions and 89/79.5% complete suspensions. Problems or stress related to education were the reasons for suicide in 44/39% of the victims. A total of 40/35.7% had family disputes and nine/8% committed suicide due to broken love affairs. There were eight/7.1% who had multiple other reasons. A note of suicide was found in only 16/14.3% of the cases. A total of 61/54.5% had used a rope (coir [25%] or nylon [29.5%]) as the ligature material. A total of 26/23.2% had used a soft fabric and 12 others had used various other materials including belts (10.7%). A total of 13/11.6% were brought without a ligature. The majority (102) were having only the imprint of the ligature on the neck. There were six having peri-ligature injuries in addition to the ligature mark. There were four/3.6% with no injuries to the neck. The pattern of the ligature mark was continuous in 92/82%. A total of 20 out of 26 individuals who had used a soft fabric had a continuous ligature mark. The ligature mark was absent only in four of the victims and two of them were using a soft fabric. The ligature mark was rising to an inverted V in the majority 81/72.3%. However, there were eight/7.1% with a horizontal ligature mark and two/1.8% with multiple marks. There were 17/15.2% with a variable pattern in their ligature mark while four/3.6% were having no ligature mark. The mark was placed high on the neck in 100 individuals. A total of 82 out of them were complete suspensions. Out of the seven individuals with a low ligature mark, four were partial suspensions. There was a significant difference between the two groups. The gap or the point of suspension was found at the back of the neck (centre of the occiput) in 52/46% while the mark was high on the neck in 51/98% out of them. A total of 29/85% out of the 34 individuals whose knot was found at the side had the ligature mark placed high on the neck. Out of the seven low lying ligatures, the majority were having the point of suspension at the side of the neck. This was a statistically significant finding. On the other hand, the degree of suspension did not show any significant association with the type of hanging - typical or atypical. Classical signs were found in 41/36.6% of the victims. Of them, the commonly observed classic sign was congestion (29/25.9%). A total of 26 out of 41 had petechial haemorrhages (areas of peri-capillary bleeding that occur in a wide spectrum of disorders, which are ruptures of the microscopic capillaries that provide blood to the body's cells) and 11 had oedema (a build-up of fluid in the body which causes the affected tissue to become swollen). The presence of the classic signs showed a statistically significant association to partial suspension. The presence of the classic signs did not show any significant association to the placement of the ligature mark. Internal injuries were observed in 38/33.9% and it was found directly underlying the external injuries in 36. The commonly observed internal injuries were fractures (33). Underlying contusions were found among 10 and two had haematomas (a bad bruise which happens when an injury causes blood to collect and pool under the skin, with the pooling blood giving the skin a spongy, rubbery, lumpy feel). In a majority, the fractures were placed on the thyroid cartilage and the hyoid (a small ‘u’ shaped, horse-shoe shaped, solitary bone, situated in the midline of the neck) bone. There is no significant association of the ligature material used with the presence or absence of internal injuries. A total of 70% of the victims of complete suspension and 52% of the individuals with partial suspension had no internal injuries. Further, there is no significant difference between the two groups; partial and complete suspension, concerning the presence of internal injuries.
Not one but many
In addition to the typical autopsy findings, various atypical findings associated with death due to hanging are reported. The appearance of a ligature mark and other findings at the autopsy depend on many factors.
The majority of the deaths due to hanging were of males who were young to middle aged. The majority (70%) were found hanging inside their home. Easy accessibility and the secluded environment may be the underlying reasons for this finding. L. Biddle, J. Donovan, A. Owen-Smith, J. Potokar, D. Longson, K. Hawton, N. Kapur and D. Gunnell's "Factors influencing the decision to use hanging as a method of suicide: Qualitative study" which studied survivors of near fatal suicide attempts, found that the victims had considered hanging as an easy and straightforward method both in terms of access to materials and the ease of implementation.
In this study, the majority (80%) were complete suspensions. However, D.E. Dean, L.J. Kohler, G.C. Sterbenz, P.J. Gillespie, N.S. Gonzaga, L.J. Bauer, K. Looman and O. Owens's "Observed characteristics of suicidal hangings: An 11-year retrospective review" found partial suspension as a common presentation.
Issues related to education were the underlying reason for suicide among the majority (39%) followed by family disputes. Risk factors for suicide, per another Indian study, vary according to country, culture, religion, gender, age, and social values. There is an increasing concern regarding study related pressure and its relationship with mental health problems. P.J. Ayanthi, M.T. Hirunavukarasu and R. Rajkumar's "Academic stress and depression among adolescents: A cross sectional study" notes that academic stress is associated with depression among adolescents. The findings highlight the importance of targeting preventive strategies for the victims of the highly competitive academic environment in this country. In yet another Indian study done among the lower socio-economic, rural population, depressive disorders, other psychiatric disorders and family matters were identified as the major risk factors for suicide.
Finding a note of suicide is strong corroborative evidence in concluding the manner of death. However, a note of suicide was found only in 16/14.3% of the cases. In the "Incidence of note leaving remains constant despite increasing suicide rates" by T. Shioiri, A. Nishimura, K. Akazawa, R. Abe, H. Nushida, Y. Ueno, M. Kojika-Maruyama and T. Someya, in Japan, the mean incidence of finding a note of suicide was 30.1%. There may be cultural, ethnic, and racial variations associated with this behaviour.
A total of 55% of the victims had used coir or a nylon rope as the ligature material followed by a soft fabric in 23%. This can be explained by the easy availability and accessibility of nylon or coir ropes used for domestic work in Sri Lanka. V.N. Ambade, N. Tumram, S. Meshram and J. Borkar's "Ligature material in hanging deaths: The neglected area in forensic examination" found that 62% of the victims were using a nylon rope as a ligature material in hanging deaths. Further, A. Pradhan, B.K. Mandal and C.B. Tripathi's "Hanging: Nature of the ligature material applied and the type of hanging according to the point of suspension" notes that many other studies from Asia report rope as the commonest ligature material. In still another Indian study, soft fabric was reported as the commonest ligature material which again can be considered as a cultural variation.
A ligature mark was observed in 96%. There were associated peri-ligature injuries in 5.4% individuals. M.M.M. Shaikh, H.J. Chotaliya, A.D. Modi, A.P. Parmar and S.D. Kalele's "A study of gross post-mortem findings in cases of hanging and ligature strangulation" found peri-ligature injuries in the form of abrasion bruises and rope burns in 16.28% of the cases of hanging. Nail marks over the neck are usually suggestive of manual strangulation and may mislead the forensic pathologist in drawing conclusions. However, according to M.K. Mohanty, P. Rastogi, G.P. Kumar, V. Kumar and S. Manipady's "Peri-ligature injuries in hanging", they are also known to be caused as self inflicted by the victim while trying to remove himself/herself from the strangling grip of hanging at the last moment.
The pattern of the ligature mark was continuous in 82% of them. Even in individuals who had used a soft fabric, the majority had a continuous ligature mark. The ligature mark was absent only in four of the victims and two of them were using a soft fabric. This study revealed that there is no significant correlation of the pattern of the ligature mark to the ligature material.
The ligature mark was found high on the neck in 100 individuals and was rising to an inverted V shape in 72%. The association of complete suspension with a high ligature mark was observed with a statistical significance. S. Jayaprakash and K. Sreekumari's "Pattern of injuries to neck structures in hanging – An autopsy study" reported that partial suspension is found commonly associated with a low ligature mark. The high and rising or oblique ligature mark is described as a differentiating factor of hanging and ligature strangulation.
The mark was rising towards the point of suspension or the knot was found at the back of the neck (typical hanging) in 46% followed by behind the ear in 30%. Thus, the majority belonged in the group of atypical hanging where the knot is not at the back of the neck. There was a significant association of the placement of the point of suspension, whether back or front or on the side, with the placement of the ligature mark on the neck where a high ligature was found to show an association with the point of suspension at the back while a low lying ligature was having an association with the point of suspension at the side. However, there was no significant association of the degree of suspension with the placement of the knot. A.K. Samanta and S.R. Nayak's "Newer trends in hanging death" reported the majority adopting complete and atypical hanging.
The majority of the victims were not having the classic signs (63%). The commonly observed classic sign was congestion followed by petechial haemorrhages. Classic signs were absent in the majority of the complete suspensions while they were commonly observed in the partial suspensions with a statistically significant association. Classic signs are a result of purely mechanical vascular phenomena or obstructed venous return in the presence of continued arterial input. S.F. Ely and C.S. Hirsch's "Asphyxial deaths and petechiae: A review" explained that as pressure builds in venules and capillaries, particularly those with little surrounding connective tissue support, such as the conjunctivae and eyelids, vascular rupture produces petechiae. Since partial suspension is adequate to obstruct the veins while the arterial supply is continuing, theoretically, classic signs are more commonly observed in partial suspensions, per R. Clément, J.P. Guay, M. Redpath and A. Sauvageau's "Petechiae in hanging: A retrospective study of contributing variables". This study further confirmed the theory and revealed a significant difference in the presence of classic signs in partial suspensions compared to the complete suspension. On the other hand, the high or low placement of the ligature mark did not show any significant association with the presence of classic signs.
Nature of internal injuries
Internal injuries were absent in the majority. When present, they were found directly underlying the ligature mark in a majority. The commonest nature of internal injury was fractures and they involved the thyroid cartilage or the hyoid bone.
This contrasts with a different Indian study where internal injuries were commonly observed and the nature was of soft tissue contusions. Since the study was done retrospectively, the possible handling of artifacts at evisceration and proper documentation and discrimination cannot be assured. There is no significant statistical association of the presence or absence of internal injuries with the type of suspension, partial and complete, or the ligature material used.
This study revealed that the findings vary and could be found in many combinations, sometimes with exceptions to that which is generally accepted. Therefore, awareness of these combinations and the exceptions are of crucial importance in coming to a conclusion in a suspected case of hanging so as to avoid any erroneous opinion. Findings in this study confirmed the existing literature on many occasions but contrasted in some especially with regard to the type of internal injury. This was identified as a limitation in a retrospective study where there is a possibility of handling artifacts.