Epidemiological, Gross Morphological, And Histopathological Analysis Of Postmortem Cases Of Hanging - An Observational Study

Study type: Observation study

Institutional Ethical committee clearance (IEC:485/2022) was taken before starting the study from the Kasturba Medical College and Kasturba Hospital institutional ethics committee on 8^th February, 2023.

We used the STROBE reporting guidelines for our study; a completed checklist is available under Reporting Guidelines.⁴

Study Period: The current research was carried out from February 2023 to June 2024

Study location: Department of Forensic Medicine in association with the Department of Pathology.

Sample Size: 46 Autopsy cases.

Inclusion criteria

Exclusion criteria

Detailed description of procedure/processes:

Ethics committee has given the exemption from taking consent from the relatives of the deceased since these cases are postmortem cases where the law gives the consent for autopsy and determination of cause of death. In the above cases the samples were taken from death due to hanging so, the tissue must be taken out to determine the cause of death. The consent given by the law for autopsy is valid. The following details were collected from the police inquest documents, police intimation documents, bystanders of the deceased, and police:

Procedure for external examination

Following the collection of the above data, and subject to fulfilment of inclusion criteria, the case was selected for the study and subjected to detailed post-mortem examination (autopsy). The external examination includes noting the presence or absence of ligature material in situ around neck. Type and manner of hanging was noted down. If present, type of ligature material used, type and position of knot, and any other significant features were noted, after which ligature material was secured with twine, ligated, and removed. Following this, clothes were examined and removed. The visible ligature mark was assessed for location with respect to the thyroid cartilage, and whether completely or incompletely encircling the neck was noted (Figure 1). The rest of the general post-mortem external examination is conducted. After noting all the external features, the neck was dissected for internal examination.

Figure 1. Showing ligature mark present at the level of thyroid cartilage.

Procedure for neck dissection and internal examination

The linear incision for thorax and abdominal examination and evisceration is made from suprasternal notch to pubic symphysis, avoiding the umbilicus. A modification of Lettulle’s technique is used and evisceration is done, removing structures below the level of the lower end of the trachea corresponding to the sternoclavicular joint to the recto-sigmoid junction. Cranial dissection including stripping of dura is done, thus creating a bloodless field of dissection in the neck.

A 12-20 cm high block is placed underneath the shoulders, thus extending the neck for dissection. The skin incision is extended from the suprasternal notch to the symphysis menti. A 5 × 2 cm × striated muscle deep, tissue sample from the maximum compression area in the ligature mark, along with the tissue present above and below the ligature mark, is taken. The two latter areas are marked using India ink and the entire sample is preserved in 10% neutral buffered formalin and sent for histopathological examination. Using toothed forceps to hold the skin, dissection is done through the plane of the underlying subcutaneous tissue, up to the lower margins of the mandible, thus exposing the platysma muscle. The platysma muscle and deep cervical fascia are reflected to expose the muscles of the neck. The sternocleidomastoid muscle is identified, and its sternal and clavicular attachments are cut, and muscle is reflected upwards. This reveals the omohyoid muscle underneath. The inferior belly of the omohyoid muscle is cut and the muscle is reflected upwards, along with the median raphe and superior belly. The sternohyoid and the sternothyroid muscles are then identified and reflected upwards. This exposes the thyroid gland, which is dissected at the isthmus and reflected outwards to reveal the trachea underneath. Blunt dissection is used to separate the laryngeal apparatus, trachea, and pharynx from prevertebral tissue.

Opening the mouth, the tongue is pushed backward and upwards using forceps. Using a tongue knife inserted under the mandible, the attachment of muscles of the floor of the mouth and neck muscles are dissected. The dissection is continued backward, taking care to avoid the carotid arteries, and downwards up to the suprasternal notch and the pharynx and laryngeal structures are dissected out. The carotid arteries are divided in the neck and then removed. The hyoid bone is separated from its muscular attachments and examined. Later, the tissue was taken out for histopathological examination.

Procedure for histopathology examination

The tissue was allowed to fixate for a minimum of eight hours in neutral buffered formalin. The tissue was dissected methodically beginning from the epidermis extending down to the dermis and the hypodermis. The sections were passed entirely and placed in tissue processor. The sections were embedded using paraplast as the embedding media. The section cutting was done using a 5-micrometre thickness and serial sections of the tissue (3 in number) were placed on the glass slide for staining. Staining was done by using hematoxylin and eosin (automated method). Special stains such as Masson trichrome (for collagen and fibrin) & elastic van Gieson (for elastin) were performed. The slides were mounted using DPX as the refractory medium. The slides were reviewed separately by a pathology resident and subsequently by a consultant, and observations were noted and classified according to Dettmeyer’s classification.⁵

Statistical analysis

Statistical analysis was done for the obtained parameters and results are presented in percentage, tables and graphs/charts.

Underlying data is included in the Underlying Data section.⁶

Age

The age distribution of the deceased in the study ranges from 15 to 82 years. The mean age was 43.9 years. The maximum number of cases was observed in the age group of 41 to 50 years, with a significant male preponderance in this age group as Shown in Table 1.

Gender

Among the deceased, the maximum number were males 37 (80.4%) when compared to females 9 (19.6%).

Marital status

Of the deceased, 30 (65.2%) were married, 15 (32.6%) were unmarried and 1 (2.2%) were divorced. Among the married population, males were observed in more significant numbers (24 males).

Occupation

The various occupations were classified into student, professional, clerical work, daily wage worker, housewife (homemakers), and unemployed. Among these, the highest incidence was among the daily wage workers (37%). The occupation-wise distribution is given in Table 2.

Place of occurrence

The case density based on location is given in Table 3.

Associated intoxication

In 12 (26.1%) of the cases, there was associated intoxication by means of consumption of alcohol, of which the maximum number were found in the age group of 41 – 50 years. In 34 (73.9%) of cases there was no intoxication seen.

Case background

Depression 19 (41.3%) was the most cited reason for suicide in both males and females, with the greatest number of cases recorded in the 21-30 years, 31-40 years and 41-50 years age groups (4 cases per group). This was followed by health issues 10 (21.7), family conflict 7 (15.2), financial issues 5 (10.9), psychiatric illness 4 (8.7%) and work stress 1 (2.2%).

Signs of asphyxia

Congestion of the face was present in 15 (32.6%) of cases, and bluish discoloration of fingernails (cyanosis) was present in 42 (91.3%) of cases, however, oedema of the face was observed only in 2 (4.3%) of cases, and petechial haemorrhages were not observed in any cases.

Signs of neck compression

Salivary dribbling was observed in 4 (8.7%) of cases whereas the characteristic ‘La facie sympathique was not observed in any cases.

General post-mortem findings

Post-mortem lividity was observable in all cases, out of which, in 13 (28.3%) lividity was fixed and in 33 (71.7%), lividity was not fixed. Faecal stains alone were observed in 4 (8.7%) of cases, and seminal stains alone in 21 (45.7%) of cases. Both faecal and seminal stains were present in 5 (10.9%) of the cases. No urinary stains were observed in any of the cases. Subconjunctival haemorrhages were observed in 2 (4.3%) of the cases. 12 (26.1%) of the cases showed associated injuries.

Features of ligature material and ligature mark

Ligature material

Out of the 46 autopsy cases, ligature material was absent during post-mortem examination in 5 of the cases. Therefore, they could not be assessed. The various ligature materials that were observed include nylon rope 19 (46.3%), saree 5 (12.2%), shawl 5 (12.2%), unrecognizable cloth 3 (7.3%), bedsheet 2 (4.9%), towel 2 (4.9%), dhothi 2 (4.9%), coir rope 1 (2.4%), electrical wire 1 (2.4%), and luggage belt 1 (2.4%).

Type and position of knot

The ligature mark was found to run upwards and backwards from midline of the neck and was situated at a point above the thyroid cartilage in all the cases studied. Type and position of knot is shown in Tables 4 and 5.

Type and manner of hanging

All the autopsy cases of hanging in the study were suicidal in nature. 32 (69.6%) were cases of partial hanging while 14 (30.4%) of cases were complete hanging.

Injuries to soft tissues and vasculature of the neck

The subcutaneous tissue in 44 (95.7%) of the cases was pale and glistening in nature, and unremarkable in 2 (4.3%) of the cases. Strap muscle contusions were observed in 2 (4.3%) of cases with one case showing contusion of both the sternohyoid and the sternothyroid muscle and one case of contusion of only the sternothyroid muscle.

Contusion of the sternocleidomastoid muscle was observed in 6 (13%) of the cases, all of them being cases of complete hanging. Out of these, most cases (3 in number) were those of atypical position of knot. Saree was used in two of the above cases. Other muscles of the neck were unremarkable in all cases studied.

Carotid intimal tears were noted in 3 (6.5%) of the cases, of which all were cases of complete hanging with atypical position of the knot of ligature material. Nylon rope, saree and unrecognizable cloth material were used in each of the cases. No instances of thyroid gland injuries were noted.

Injuries to bony and cartilaginous structures of the neck

Hyoid bone and cervical vertebrae fractures were observed in 8 (17.4%) and 1 (2.2%) of the autopsy cases. Of the cases with hyoid bone fracture, most cases had an atypical position of the knot with nylon rope being used as the ligature material (4 cases). There was an even distribution of complete and partial hanging cases with hyoid bone fractures. No fractures were observed among the cartilages of the larynx.

Contusion of the hyoid bone was seen in 7 (15.2%) of cases, with most cases being those of complete hanging (5 cases), atypical position of knot (4 cases) and with nylon rope as the ligature material (4 cases). Contusion of thyroid cartilage was seen in 5 (10.9%) of cases, with distribution roughly like that of hyoid bone contusion. Contusions were not observed among other cartilages of larynx or cervical vertebrae.

Vital reaction

In the tissue corresponding to the region of ligature mark, vital reaction was observed in 100% of cases. The regions above and below the region of ligature mark did not show features of extravasation of red blood cells or any features of vital reaction in any of the cases.

Time since injury

Time since injury was broadly divided into fresh vital injury, vital wound, wound incurred shortly before or after death, not yet old and no longer fresh. The pattern of distribution of time since injury is given in the Table 6. Histopathological pictures of the tissues are shown in Figures 2-6.

Figure 2. Wound incurred shortly, before or after death.

(A) – H&E, 100×, (B) – H&E – 400×.

Category 1. Wound incurred shortly, before or after death is shown in Figure 2. The epidermis is intact. The dermal collagen and vessels are unremarkable. No active immune reaction is noted. Category 2. Vital wound-inflicted during lifetime is shown in Figure 3. The epidermis is eroded (black arrow) and the dermal collagen shows disruption of fibroblasts (arrow heads). Category 3. Fresh vital injury (hours to a few days) is shown in Figure 4. The epidermis is eroded. The dermis shows a reaction with RBC extravasation (arrowhead) and vessels with fibrin thrombi (black arrow). Category 4. Vital wound-no longer fresh. (few days to weeks-in single digit range) is shown in Figure 5. The dermis shows a dense neutrophilic reaction (black arrow) with admixed mononuclear cells and macrophages, new vessel formation (arrow heads). Category 5. Vital Injury-Not very old (weeks to months) is shown in Figure 6. The epidermis is regenerating. Thick sclerosed collagen (arrow heads), representing scar tissue; with loss of dermal adnexal structures and scant inflammation.

Figure 3. Vital wound-inflicted during lifetime.

(A) – H&E, 100×, (B) – H&E – 400×.

Figure 4. Fresh vital injury (hours to a few days).

Fresh vital injury (hours to a few days). (A) – H&E, 100×, (B) – H&E – 400×.

Figure 5. Vital wound-no longer fresh.

(few days to weeks-in single digit range). (a) – H&E, 400×, (b) – H&E – 400×.

Figure 6. Vital Injury-Not very old (weeks to months).

H&E, 100×.

Limitations of the study

This study was an attempt to bridge the existing knowledge gap in suicidal cases of hanging. It is evident from this study that socio-demographic factors play a significant role in the circumstances leading to suicidal deaths. Therefore, in reducing the burden of suicidal deaths, these factors must be addressed. The analysis of various gross features shows that the findings in existing literature are not always observed practically and in real-world situations. Finally, further research on the estimation of wound vitality and a consensus on the definition of the term ‘vital reaction’ will be of great forensic value.